From: "Jørgen Kvalsvik" <j@lambda.is>
To: gcc-patches@gcc.gnu.org
Cc: hubicka@ucw.cz, richard.guenther@gmail.com
Subject: Ping [PATCH v10 1/2] Add condition coverage (MC/DC)
Date: Tue, 12 Mar 2024 21:40:06 +0100 [thread overview]
Message-ID: <ac7ac89b-b495-42a2-8a8e-95f4438ee378@lambda.is> (raw)
In-Reply-To: <20240223111800.1209438-1-j@lambda.is>
On 23/02/2024 12:17, Jørgen Kvalsvik wrote:
> This patch adds support in gcc+gcov for modified condition/decision
> coverage (MC/DC) with the -fcondition-coverage flag. MC/DC is a type of
> test/code coverage and it is particularly important for safety-critical
> applicaitons in industries like aviation and automotive. Notably, MC/DC
> is required or recommended by:
>
> * DO-178C for the most critical software (Level A) in avionics.
> * IEC 61508 for SIL 4.
> * ISO 26262-6 for ASIL D.
>
> From the SQLite webpage:
>
> Two methods of measuring test coverage were described above:
> "statement" and "branch" coverage. There are many other test
> coverage metrics besides these two. Another popular metric is
> "Modified Condition/Decision Coverage" or MC/DC. Wikipedia defines
> MC/DC as follows:
>
> * Each decision tries every possible outcome.
> * Each condition in a decision takes on every possible outcome.
> * Each entry and exit point is invoked.
> * Each condition in a decision is shown to independently affect
> the outcome of the decision.
>
> In the C programming language where && and || are "short-circuit"
> operators, MC/DC and branch coverage are very nearly the same thing.
> The primary difference is in boolean vector tests. One can test for
> any of several bits in bit-vector and still obtain 100% branch test
> coverage even though the second element of MC/DC - the requirement
> that each condition in a decision take on every possible outcome -
> might not be satisfied.
>
> https://sqlite.org/testing.html#mcdc
>
> MC/DC comes in different flavours, the most important being unique
> cause MC/DC and masking MC/DC. This patch implements masking MC/DC,
> which is works well with short circuiting semantics, and according to
> John Chilenski's "An Investigation of Three Forms of the Modified
> Condition Decision Coverage (MCDC) Criterion" (2001) is as good as
> unique cause at catching bugs.
>
> Whalen, Heimdahl, and De Silva "Efficient Test Coverage Measurement for
> MC/DC" describes an algorithm for determining masking from an AST walk,
> but my algorithm figures this out from analyzing the control flow graph.
> The CFG is considered a binary decision diagram and an evaluation
> becomes a path through the BDD, which is recorded. Certain paths will
> mask ("null out") the contribution from earlier path segments, which can
> be determined by finding short circuit endpoints. Masking is the
> short circuiting of terms in the reverse-ordered Boolean function, and
> the masked terms do not affect the decision like short-circuited
> terms do not affect the decision.
>
> A tag/discriminator mapping from gcond->uid is created during
> gimplification and made available through the function struct. The
> values are unimportant as long as basic conditions constructed from a
> single Boolean expression are given the same identifier. This happens in
> the breaking down of ANDIF/ORIF trees, so the coverage generally works
> well for frontends that create such trees.
>
> Like Whalen et al this implementation records coverage in fixed-size
> bitsets which gcov knows how to interpret. This takes only a few bitwise
> operations per condition and is very fast, but comes with a limit on the
> number of terms in a single boolean expression; the number of bits in a
> gcov_unsigned_type (which is usually typedef'd to uint64_t). For most
> practical purposes this is acceptable, and by default a warning will be
> issued if gcc cannot instrument the expression. This is a practical
> limitation in the implementation, not the algorithm, so support for more
> conditions can be added by also introducing arbitrary-sized bitsets.
>
> In action it looks pretty similar to the branch coverage. The -g short
> opt carries no significance, but was chosen because it was an available
> option with the upper-case free too.
>
> gcov --conditions:
>
> 3: 17:void fn (int a, int b, int c, int d) {
> 3: 18: if ((a && (b || c)) && d)
> conditions covered 3/8
> condition 0 not covered (true false)
> condition 1 not covered (true)
> condition 2 not covered (true)
> condition 3 not covered (true)
> 1: 19: x = 1;
> -: 20: else
> 2: 21: x = 2;
> 3: 22:}
>
> gcov --conditions --json-format:
>
> "conditions": [
> {
> "not_covered_false": [
> 0
> ],
> "count": 8,
> "covered": 3,
> "not_covered_true": [
> 0,
> 1,
> 2,
> 3
> ]
> }
> ],
>
> Expressions with constants may be heavily rewritten before it reaches
> the gimplification, so constructs like int x = a ? 0 : 1 becomes
> _x = (_a == 0). From source you would expect coverage, but it gets
> neither branch nor condition coverage. The same applies to expressions
> like int x = 1 || a which are simply replaced by a constant.
>
> The test suite contains a lot of small programs and functions. Some of
> these were designed by hand to test for specific behaviours and graph
> shapes, and some are previously-failed test cases in other programs
> adapted into the test suite.
>
> gcc/ChangeLog:
>
> * builtins.cc (expand_builtin_fork_or_exec): Check
> condition_coverage_flag.
> * collect2.cc (main): Add -fno-condition-coverage to OBSTACK.
> * common.opt: Add new options -fcondition-coverage and
> -Wcoverage-too-many-conditions.
> * doc/gcov.texi: Add --conditions documentation.
> * doc/invoke.texi: Add -fcondition-coverage documentation.
> * function.cc (free_after_compilation): Free cond_uids.
> * function.h (struct function): Add cond_uids.
> * gcc.cc: Link gcov on -fcondition-coverage.
> * gcov-counter.def (GCOV_COUNTER_CONDS): New.
> * gcov-dump.cc (tag_conditions): New.
> * gcov-io.h (GCOV_TAG_CONDS): New.
> (GCOV_TAG_CONDS_LENGTH): New.
> (GCOV_TAG_CONDS_NUM): New.
> * gcov.cc (class condition_info): New.
> (condition_info::condition_info): New.
> (condition_info::popcount): New.
> (struct coverage_info): New.
> (add_condition_counts): New.
> (output_conditions): New.
> (print_usage): Add -g, --conditions.
> (process_args): Likewise.
> (output_intermediate_json_line): Output conditions.
> (read_graph_file): Read condition counters.
> (read_count_file): Likewise.
> (file_summary): Print conditions.
> (accumulate_line_info): Accumulate conditions.
> (output_line_details): Print conditions.
> * gimplify.cc (next_cond_uid): New.
> (reset_cond_uid): New.
> (shortcut_cond_r): Set condition discriminator.
> (tag_shortcut_cond): New.
> (gimple_associate_condition_with_expr): New.
> (shortcut_cond_expr): Set condition discriminator.
> (gimplify_cond_expr): Likewise.
> (gimplify_function_tree): Call reset_cond_uid.
> * ipa-inline.cc (can_early_inline_edge_p): Check
> condition_coverage_flag.
> * ipa-split.cc (pass_split_functions::gate): Likewise.
> * passes.cc (finish_optimization_passes): Likewise.
> * profile.cc (struct condcov): New declaration.
> (cov_length): Likewise.
> (cov_blocks): Likewise.
> (cov_masks): Likewise.
> (cov_maps): Likewise.
> (cov_free): Likewise.
> (instrument_decisions): New.
> (read_thunk_profile): Control output to file.
> (branch_prob): Call find_conditions, instrument_decisions.
> (init_branch_prob): Add total_num_conds.
> (end_branch_prob): Likewise.
> * tree-core.h (struct tree_exp): Add condition_uid.
> * tree-profile.cc (struct conds_ctx): New.
> (CONDITIONS_MAX_TERMS): New.
> (EDGE_CONDITION): New.
> (topological_cmp): New.
> (index_of): New.
> (single_p): New.
> (single_edge): New.
> (contract_edge_up): New.
> (struct outcomes): New.
> (conditional_succs): New.
> (condition_index): New.
> (condition_uid): New.
> (masking_vectors): New.
> (emit_assign): New.
> (emit_bitwise_op): New.
> (make_top_index_visit): New.
> (make_top_index): New.
> (paths_between): New.
> (struct condcov): New.
> (cov_length): New.
> (cov_blocks): New.
> (cov_masks): New.
> (cov_maps): New.
> (cov_free): New.
> (find_conditions): New.
> (struct counters): New.
> (find_counters): New.
> (resolve_counter): New.
> (resolve_counters): New.
> (instrument_decisions): New.
> (tree_profiling): Check condition_coverage_flag.
> (pass_ipa_tree_profile::gate): Likewise.
> * tree.h (SET_EXPR_UID): New.
> (EXPR_COND_UID): New.
>
> libgcc/ChangeLog:
>
> * libgcov-merge.c (__gcov_merge_ior): New.
>
> gcc/testsuite/ChangeLog:
>
> * lib/gcov.exp: Add condition coverage test function.
> * g++.dg/gcov/gcov-18.C: New test.
> * gcc.misc-tests/gcov-19.c: New test.
> * gcc.misc-tests/gcov-20.c: New test.
> * gcc.misc-tests/gcov-21.c: New test.
> * gcc.misc-tests/gcov-22.c: New test.
> * gcc.misc-tests/gcov-23.c: New test.
> ---
> gcc/builtins.cc | 2 +-
> gcc/collect2.cc | 7 +-
> gcc/common.opt | 9 +
> gcc/doc/gcov.texi | 38 +
> gcc/doc/invoke.texi | 21 +
> gcc/function.cc | 1 +
> gcc/function.h | 4 +
> gcc/gcc.cc | 4 +-
> gcc/gcov-counter.def | 3 +
> gcc/gcov-dump.cc | 24 +
> gcc/gcov-io.h | 3 +
> gcc/gcov.cc | 209 ++-
> gcc/gimplify.cc | 123 +-
> gcc/ipa-inline.cc | 2 +-
> gcc/ipa-split.cc | 2 +-
> gcc/passes.cc | 3 +-
> gcc/profile.cc | 76 +-
> gcc/testsuite/g++.dg/gcov/gcov-18.C | 282 ++++
> gcc/testsuite/gcc.misc-tests/gcov-19.c | 1737 ++++++++++++++++++++++++
> gcc/testsuite/gcc.misc-tests/gcov-20.c | 22 +
> gcc/testsuite/gcc.misc-tests/gcov-21.c | 16 +
> gcc/testsuite/gcc.misc-tests/gcov-22.c | 103 ++
> gcc/testsuite/gcc.misc-tests/gcov-23.c | 361 +++++
> gcc/testsuite/lib/gcov.exp | 259 +++-
> gcc/tree-core.h | 3 +
> gcc/tree-profile.cc | 1058 ++++++++++++++-
> gcc/tree.h | 4 +
> libgcc/libgcov-merge.c | 5 +
> 28 files changed, 4339 insertions(+), 42 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/gcov/gcov-18.C
> create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-19.c
> create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-20.c
> create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-21.c
> create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-22.c
> create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-23.c
>
> ---
> Changes since v9:
>
> * function->cond_uid is no longer in ggc memory
> * function->cond_uid and condition annotation is only done when coverage
> is requested
> * A few new test cases, notably interactions with C++ constexpr
> * Updated comments based on review feedback
> ---
>
> diff --git a/gcc/builtins.cc b/gcc/builtins.cc
> index aa86ac1545d..f2a044bbbfa 100644
> --- a/gcc/builtins.cc
> +++ b/gcc/builtins.cc
> @@ -5994,7 +5994,7 @@ expand_builtin_fork_or_exec (tree fn, tree exp, rtx target, int ignore)
> tree call;
>
> /* If we are not profiling, just call the function. */
> - if (!profile_arc_flag)
> + if (!profile_arc_flag && !condition_coverage_flag)
> return NULL_RTX;
>
> /* Otherwise call the wrapper. This should be equivalent for the rest of
> diff --git a/gcc/collect2.cc b/gcc/collect2.cc
> index c943f9f577c..af920ff2033 100644
> --- a/gcc/collect2.cc
> +++ b/gcc/collect2.cc
> @@ -1035,9 +1035,9 @@ main (int argc, char **argv)
> lto_mode = LTO_MODE_LTO;
> }
>
> - /* -fno-profile-arcs -fno-test-coverage -fno-branch-probabilities
> - -fno-exceptions -w -fno-whole-program */
> - num_c_args += 6;
> + /* -fno-profile-arcs -fno-condition-coverage -fno-test-coverage
> + -fno-branch-probabilities -fno-exceptions -w -fno-whole-program */
> + num_c_args += 7;
>
> c_argv = XCNEWVEC (char *, num_c_args);
> c_ptr = CONST_CAST2 (const char **, char **, c_argv);
> @@ -1233,6 +1233,7 @@ main (int argc, char **argv)
> }
> obstack_free (&temporary_obstack, temporary_firstobj);
> *c_ptr++ = "-fno-profile-arcs";
> + *c_ptr++ = "-fno-condition-coverage";
> *c_ptr++ = "-fno-test-coverage";
> *c_ptr++ = "-fno-branch-probabilities";
> *c_ptr++ = "-fno-exceptions";
> diff --git a/gcc/common.opt b/gcc/common.opt
> index 161a035d736..b93850b48dd 100644
> --- a/gcc/common.opt
> +++ b/gcc/common.opt
> @@ -870,6 +870,11 @@ Wcoverage-invalid-line-number
> Common Var(warn_coverage_invalid_linenum) Init(1) Warning
> Warn in case a function ends earlier than it begins due to an invalid linenum macros.
>
> +Wcoverage-too-many-conditions
> +Common Var(warn_too_many_conditions) Init(1) Warning
> +Warn when a conditional has too many terms and condition coverage profiling
> +gives up instrumenting the expression.
> +
> Wmissing-profile
> Common Var(warn_missing_profile) Init(1) Warning
> Warn in case profiles in -fprofile-use do not exist.
> @@ -2458,6 +2463,10 @@ fprofile-arcs
> Common Var(profile_arc_flag)
> Insert arc-based program profiling code.
>
> +fcondition-coverage
> +Common Var(condition_coverage_flag)
> +Insert condition coverage profiling code.
> +
> fprofile-dir=
> Common Joined RejectNegative Var(profile_data_prefix)
> Set the top-level directory for storing the profile data.
> diff --git a/gcc/doc/gcov.texi b/gcc/doc/gcov.texi
> index 3019efc4674..6bd75959e94 100644
> --- a/gcc/doc/gcov.texi
> +++ b/gcc/doc/gcov.texi
> @@ -124,6 +124,7 @@ gcov [@option{-v}|@option{--version}] [@option{-h}|@option{--help}]
> [@option{-a}|@option{--all-blocks}]
> [@option{-b}|@option{--branch-probabilities}]
> [@option{-c}|@option{--branch-counts}]
> + [@option{-g}|@option{--conditions}]
> [@option{-d}|@option{--display-progress}]
> [@option{-f}|@option{--function-summaries}]
> [@option{-j}|@option{--json-format}]
> @@ -169,6 +170,14 @@ be shown, unless the @option{-u} option is given.
> Write branch frequencies as the number of branches taken, rather than
> the percentage of branches taken.
>
> +@item -g
> +@itemx --conditions
> +Write condition coverage to the output file, and write condition summary info
> +to the standard output. This option allows you to see if the conditions in
> +your program at least once had an independent effect on the outcome of the
> +boolean expression (modified condition/decision coverage). This requires you
> +to compile the source with @option{-fcondition-coverage}.
> +
> @item -d
> @itemx --display-progress
> Display the progress on the standard output.
> @@ -301,6 +310,7 @@ Each @var{line} has the following form:
> "branches": ["$branch"],
> "calls": ["$call"],
> "count": 2,
> + "conditions": ["$condition"],
> "line_number": 15,
> "unexecuted_block": false,
> "function_name": "foo",
> @@ -384,6 +394,34 @@ to @var{line::count})
> @var{destination_block_id}: ID of the basic block this calls continues after return
> @end itemize
>
> +Each @var{condition} has the following form:
> +
> +@smallexample
> +@{
> + "count": 4,
> + "covered": 2,
> + "not_covered_false": [],
> + "not_covered_true": [0, 1],
> +@}
> +
> +@end smallexample
> +
> +Fields of the @var{condition} element have following semantics:
> +
> +@itemize @bullet
> +@item
> +@var{count}: number of condition outcomes in this expression
> +
> +@item
> +@var{covered}: number of covered condition outcomes in this expression
> +
> +@item
> +@var{not_covered_true}: terms, by index, not seen as true in this expression
> +
> +@item
> +@var{not_covered_false}: terms, by index, not seen as false in this expression
> +@end itemize
> +
> @item -H
> @itemx --human-readable
> Write counts in human readable format (like 24.6k).
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index f93128dbe2b..7bfd2478555 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -635,6 +635,7 @@ Objective-C and Objective-C++ Dialects}.
> @item Program Instrumentation Options
> @xref{Instrumentation Options,,Program Instrumentation Options}.
> @gccoptlist{-p -pg -fprofile-arcs --coverage -ftest-coverage
> +-fcondition-coverage
> -fprofile-abs-path
> -fprofile-dir=@var{path} -fprofile-generate -fprofile-generate=@var{path}
> -fprofile-info-section -fprofile-info-section=@var{name}
> @@ -6547,6 +6548,14 @@ poorly optimized code and is useful only in the
> case of very minor changes such as bug fixes to an existing code-base.
> Completely disabling the warning is not recommended.
>
> +@opindex Wno-coverage-too-many-conditions
> +@opindex Wcoverage-too-many-conditions
> +@item -Wno-coverage-too-many-conditions
> +Warn if @option{-fcondition-coverage} is used and an expression have too many
> +terms and GCC gives up coverage. Coverage is given up when there are more
> +terms in the conditional than there are bits in a @code{gcov_type_unsigned}.
> +This warning is enabled by default.
> +
> @opindex Wno-coverage-invalid-line-number
> @opindex Wcoverage-invalid-line-number
> @item -Wno-coverage-invalid-line-number
> @@ -16867,6 +16876,14 @@ Note that if a command line directly links source files, the corresponding
> E.g. @code{gcc a.c b.c -o binary} would generate @file{binary-a.gcda} and
> @file{binary-b.gcda} files.
>
> +@item -fcondition-coverage
> +@opindex fcondition-coverage
> +Add code so that program conditions are instrumented. During execution the
> +program records what terms in a conditional contributes to a decision, which
> +can be used to verify that all terms in a Boolean function are tested and have
> +an independent effect on the outcome of a decision. The result can be read
> +with @code{gcov --conditions}.
> +
> @xref{Cross-profiling}.
>
> @cindex @command{gcov}
> @@ -16929,6 +16946,10 @@ executed. When an arc is the only exit or only entrance to a block, the
> instrumentation code can be added to the block; otherwise, a new basic
> block must be created to hold the instrumentation code.
>
> +With @option{-fcondition-coverage}, for each conditional in your program GCC
> +creates a bitset and records the exercised boolean values that have an
> +independent effect on the outcome of that expression.
> +
> @need 2000
> @opindex ftest-coverage
> @item -ftest-coverage
> diff --git a/gcc/function.cc b/gcc/function.cc
> index 89841787ff8..401219652a7 100644
> --- a/gcc/function.cc
> +++ b/gcc/function.cc
> @@ -216,6 +216,7 @@ free_after_compilation (struct function *f)
> f->machine = NULL;
> f->cfg = NULL;
> f->curr_properties &= ~PROP_cfg;
> + delete f->cond_uids;
>
> regno_reg_rtx = NULL;
> }
> diff --git a/gcc/function.h b/gcc/function.h
> index 833c35e3da6..d3c500859f8 100644
> --- a/gcc/function.h
> +++ b/gcc/function.h
> @@ -270,6 +270,10 @@ struct GTY(()) function {
> /* Value histograms attached to particular statements. */
> htab_t GTY((skip)) value_histograms;
>
> + /* Annotated gconds so that basic conditions in the same expression map to
> + the same same uid. This is used for condition coverage. */
> + hash_map <gcond*, unsigned> *GTY((skip)) cond_uids;
> +
> /* For function.cc. */
>
> /* Points to the FUNCTION_DECL of this function. */
> diff --git a/gcc/gcc.cc b/gcc/gcc.cc
> index 9f21ad9453e..8578abc84f7 100644
> --- a/gcc/gcc.cc
> +++ b/gcc/gcc.cc
> @@ -1165,7 +1165,7 @@ proper position among the other output files. */
> %:include(libgomp.spec)%(link_gomp)}\
> %{fgnu-tm:%:include(libitm.spec)%(link_itm)}\
> " STACK_SPLIT_SPEC "\
> - %{fprofile-arcs|fprofile-generate*|coverage:-lgcov} " SANITIZER_SPEC " \
> + %{fprofile-arcs|fcondition-coverage|fprofile-generate*|coverage:-lgcov} " SANITIZER_SPEC " \
> %{!nostdlib:%{!r:%{!nodefaultlibs:%(link_ssp) %(link_gcc_c_sequence)}}}\
> %{!nostdlib:%{!r:%{!nostartfiles:%E}}} %{T*} \n%(post_link) }}}}}}"
> #endif
> @@ -1288,7 +1288,7 @@ static const char *cc1_options =
> %{!fsyntax-only:%{S:%W{o*}%{!o*:-o %w%b.s}}}\
> %{fsyntax-only:-o %j} %{-param*}\
> %{coverage:-fprofile-arcs -ftest-coverage}\
> - %{fprofile-arcs|fprofile-generate*|coverage:\
> + %{fprofile-arcs|fcondition-coverage|fprofile-generate*|coverage:\
> %{!fprofile-update=single:\
> %{pthread:-fprofile-update=prefer-atomic}}}";
>
> diff --git a/gcc/gcov-counter.def b/gcc/gcov-counter.def
> index 727ef424181..4d5b9c65a70 100644
> --- a/gcc/gcov-counter.def
> +++ b/gcc/gcov-counter.def
> @@ -49,3 +49,6 @@ DEF_GCOV_COUNTER(GCOV_COUNTER_IOR, "ior", _ior)
>
> /* Time profile collecting first run of a function */
> DEF_GCOV_COUNTER(GCOV_TIME_PROFILER, "time_profiler", _time_profile)
> +
> +/* Conditions. The counter is interpreted as a bit-set. */
> +DEF_GCOV_COUNTER(GCOV_COUNTER_CONDS, "conditions", _ior)
> diff --git a/gcc/gcov-dump.cc b/gcc/gcov-dump.cc
> index 20e464022dc..d843223986c 100644
> --- a/gcc/gcov-dump.cc
> +++ b/gcc/gcov-dump.cc
> @@ -38,6 +38,7 @@ static void print_version (void);
> static void tag_function (const char *, unsigned, int, unsigned);
> static void tag_blocks (const char *, unsigned, int, unsigned);
> static void tag_arcs (const char *, unsigned, int, unsigned);
> +static void tag_conditions (const char *, unsigned, int, unsigned);
> static void tag_lines (const char *, unsigned, int, unsigned);
> static void tag_counters (const char *, unsigned, int, unsigned);
> static void tag_summary (const char *, unsigned, int, unsigned);
> @@ -77,6 +78,7 @@ static const tag_format_t tag_table[] =
> {GCOV_TAG_FUNCTION, "FUNCTION", tag_function},
> {GCOV_TAG_BLOCKS, "BLOCKS", tag_blocks},
> {GCOV_TAG_ARCS, "ARCS", tag_arcs},
> + {GCOV_TAG_CONDS, "CONDITIONS", tag_conditions},
> {GCOV_TAG_LINES, "LINES", tag_lines},
> {GCOV_TAG_OBJECT_SUMMARY, "OBJECT_SUMMARY", tag_summary},
> {0, NULL, NULL}
> @@ -392,6 +394,28 @@ tag_arcs (const char *filename ATTRIBUTE_UNUSED,
> }
> }
>
> +/* Print number of conditions (not outcomes, i.e. if (x && y) is 2, not 4). */
> +static void
> +tag_conditions (const char *filename, unsigned /* tag */, int length,
> + unsigned depth)
> +{
> + unsigned n_conditions = GCOV_TAG_CONDS_NUM (length);
> +
> + printf (" %u conditions", n_conditions);
> + if (flag_dump_contents)
> + {
> + for (unsigned ix = 0; ix != n_conditions; ix++)
> + {
> + const unsigned blockno = gcov_read_unsigned ();
> + const unsigned nterms = gcov_read_unsigned ();
> +
> + printf ("\n");
> + print_prefix (filename, depth, gcov_position ());
> + printf (VALUE_PADDING_PREFIX "block %u:", blockno);
> + printf (" %u", nterms);
> + }
> + }
> +}
> static void
> tag_lines (const char *filename ATTRIBUTE_UNUSED,
> unsigned tag ATTRIBUTE_UNUSED, int length ATTRIBUTE_UNUSED,
> diff --git a/gcc/gcov-io.h b/gcc/gcov-io.h
> index e6f33e32652..eda4611ac42 100644
> --- a/gcc/gcov-io.h
> +++ b/gcc/gcov-io.h
> @@ -261,6 +261,9 @@ typedef uint64_t gcov_type_unsigned;
> #define GCOV_TAG_ARCS ((gcov_unsigned_t)0x01430000)
> #define GCOV_TAG_ARCS_LENGTH(NUM) (1 + (NUM) * 2 * GCOV_WORD_SIZE)
> #define GCOV_TAG_ARCS_NUM(LENGTH) (((LENGTH / GCOV_WORD_SIZE) - 1) / 2)
> +#define GCOV_TAG_CONDS ((gcov_unsigned_t)0x01470000)
> +#define GCOV_TAG_CONDS_LENGTH(NUM) ((NUM) * 2 * GCOV_WORD_SIZE)
> +#define GCOV_TAG_CONDS_NUM(LENGTH) (((LENGTH) / GCOV_WORD_SIZE) / 2)
> #define GCOV_TAG_LINES ((gcov_unsigned_t)0x01450000)
> #define GCOV_TAG_COUNTER_BASE ((gcov_unsigned_t)0x01a10000)
> #define GCOV_TAG_COUNTER_LENGTH(NUM) ((NUM) * 2 * GCOV_WORD_SIZE)
> diff --git a/gcc/gcov.cc b/gcc/gcov.cc
> index 8b4748d3a1a..6a65e808dce 100644
> --- a/gcc/gcov.cc
> +++ b/gcc/gcov.cc
> @@ -46,6 +46,7 @@ along with Gcov; see the file COPYING3. If not see
> #include "color-macros.h"
> #include "pretty-print.h"
> #include "json.h"
> +#include "hwint.h"
>
> #include <zlib.h>
> #include <getopt.h>
> @@ -81,6 +82,7 @@ using namespace std;
> class function_info;
> class block_info;
> class source_info;
> +class condition_info;
>
> /* Describes an arc between two basic blocks. */
>
> @@ -134,6 +136,33 @@ public:
> vector<unsigned> lines;
> };
>
> +/* Describes a single conditional expression and the (recorded) conditions
> + shown to independently affect the outcome. */
> +class condition_info
> +{
> +public:
> + condition_info ();
> +
> + int popcount () const;
> +
> + /* Bitsets storing the independently significant outcomes for true and false,
> + respectively. */
> + gcov_type_unsigned truev;
> + gcov_type_unsigned falsev;
> +
> + /* Number of terms in the expression; if (x) -> 1, if (x && y) -> 2 etc. */
> + unsigned n_terms;
> +};
> +
> +condition_info::condition_info (): truev (0), falsev (0), n_terms (0)
> +{
> +}
> +
> +int condition_info::popcount () const
> +{
> + return popcount_hwi (truev) + popcount_hwi (falsev);
> +}
> +
> /* Describes a basic block. Contains lists of arcs to successor and
> predecessor blocks. */
>
> @@ -167,6 +196,8 @@ public:
> /* Block is a landing pad for longjmp or throw. */
> unsigned is_nonlocal_return : 1;
>
> + condition_info conditions;
> +
> vector<block_location_info> locations;
>
> struct
> @@ -277,6 +308,8 @@ public:
> vector<block_info> blocks;
> unsigned blocks_executed;
>
> + vector<condition_info*> conditions;
> +
> /* Raw arc coverage counts. */
> vector<gcov_type> counts;
>
> @@ -353,6 +386,9 @@ struct coverage_info
> int branches_executed;
> int branches_taken;
>
> + int conditions;
> + int conditions_covered;
> +
> int calls;
> int calls_executed;
>
> @@ -552,6 +588,10 @@ static int multiple_files = 0;
>
> static int flag_branches = 0;
>
> +/* Output conditions (modified condition/decision coverage). */
> +
> +static bool flag_conditions = 0;
> +
> /* Show unconditional branches too. */
> static int flag_unconditional = 0;
>
> @@ -658,6 +698,7 @@ static int read_count_file (void);
> static void solve_flow_graph (function_info *);
> static void find_exception_blocks (function_info *);
> static void add_branch_counts (coverage_info *, const arc_info *);
> +static void add_condition_counts (coverage_info *, const block_info *);
> static void add_line_counts (coverage_info *, function_info *);
> static void executed_summary (unsigned, unsigned);
> static void function_summary (const coverage_info *);
> @@ -666,6 +707,7 @@ static const char *format_gcov (gcov_type, gcov_type, int);
> static void accumulate_line_counts (source_info *);
> static void output_gcov_file (const char *, source_info *);
> static int output_branch_count (FILE *, int, const arc_info *);
> +static void output_conditions (FILE *, const block_info *);
> static void output_lines (FILE *, const source_info *);
> static string make_gcov_file_name (const char *, const char *);
> static char *mangle_name (const char *);
> @@ -930,6 +972,8 @@ print_usage (int error_p)
> fnotice (file, " -b, --branch-probabilities Include branch probabilities in output\n");
> fnotice (file, " -c, --branch-counts Output counts of branches taken\n\
> rather than percentages\n");
> + fnotice (file, " -g, --conditions Include modified condition/decision\n\
> + coverage in output\n");
> fnotice (file, " -d, --display-progress Display progress information\n");
> fnotice (file, " -D, --debug Display debugging dumps\n");
> fnotice (file, " -f, --function-summaries Output summaries for each function\n");
> @@ -983,6 +1027,7 @@ static const struct option options[] =
> { "all-blocks", no_argument, NULL, 'a' },
> { "branch-probabilities", no_argument, NULL, 'b' },
> { "branch-counts", no_argument, NULL, 'c' },
> + { "conditions", no_argument, NULL, 'g' },
> { "json-format", no_argument, NULL, 'j' },
> { "human-readable", no_argument, NULL, 'H' },
> { "no-output", no_argument, NULL, 'n' },
> @@ -1011,7 +1056,7 @@ process_args (int argc, char **argv)
> {
> int opt;
>
> - const char *opts = "abcdDfhHijklmno:pqrs:tuvwx";
> + const char *opts = "abcdDfghHijklmno:pqrs:tuvwx";
> while ((opt = getopt_long (argc, argv, opts, options, NULL)) != -1)
> {
> switch (opt)
> @@ -1028,6 +1073,9 @@ process_args (int argc, char **argv)
> case 'f':
> flag_function_summary = 1;
> break;
> + case 'g':
> + flag_conditions = 1;
> + break;
> case 'h':
> print_usage (false);
> /* print_usage will exit. */
> @@ -1152,6 +1200,45 @@ output_intermediate_json_line (json::array *object,
> }
> }
>
> + json::array *conditions = new json::array ();
> + lineo->set ("conditions", conditions);
> + if (flag_conditions)
> + {
> + vector<block_info *>::const_iterator it;
> + for (it = line->blocks.begin (); it != line->blocks.end (); it++)
> + {
> + const condition_info& info = (*it)->conditions;
> + if (info.n_terms == 0)
> + continue;
> +
> + const int count = 2 * info.n_terms;
> + const int covered = info.popcount ();
> +
> + json::object *cond = new json::object ();
> + cond->set ("count", new json::integer_number (count));
> + cond->set ("covered", new json::integer_number (covered));
> +
> + json::array *mtrue = new json::array ();
> + json::array *mfalse = new json::array ();
> + cond->set ("not_covered_true", mtrue);
> + cond->set ("not_covered_false", mfalse);
> +
> + if (count != covered)
> + {
> + for (unsigned i = 0; i < info.n_terms; i++)
> + {
> + gcov_type_unsigned index = 1;
> + index <<= i;
> + if (!(index & info.truev))
> + mtrue->append (new json::integer_number (i));
> + if (!(index & info.falsev))
> + mfalse->append (new json::integer_number (i));
> + }
> + }
> + conditions->append (cond);
> + }
> + }
> +
> object->append (lineo);
> }
>
> @@ -1969,6 +2056,28 @@ read_graph_file (void)
> }
> }
> }
> + else if (fn && tag == GCOV_TAG_CONDS)
> + {
> + unsigned num_dests = GCOV_TAG_CONDS_NUM (length);
> +
> + if (!fn->conditions.empty ())
> + fnotice (stderr, "%s:already seen conditions for '%s'\n",
> + bbg_file_name, fn->get_name ());
> + else
> + fn->conditions.resize (num_dests);
> +
> + for (unsigned i = 0; i < num_dests; ++i)
> + {
> + unsigned idx = gcov_read_unsigned ();
> +
> + if (idx >= fn->blocks.size ())
> + goto corrupt;
> +
> + condition_info *info = &fn->blocks[idx].conditions;
> + info->n_terms = gcov_read_unsigned ();
> + fn->conditions[i] = info;
> + }
> + }
> else if (fn && tag == GCOV_TAG_LINES)
> {
> unsigned blockno = gcov_read_unsigned ();
> @@ -2099,6 +2208,21 @@ read_count_file (void)
> goto cleanup;
> }
> }
> + else if (tag == GCOV_TAG_FOR_COUNTER (GCOV_COUNTER_CONDS) && fn)
> + {
> + length = abs (read_length);
> + if (length != GCOV_TAG_COUNTER_LENGTH (2 * fn->conditions.size ()))
> + goto mismatch;
> +
> + if (read_length > 0)
> + {
> + for (ix = 0; ix != fn->conditions.size (); ix++)
> + {
> + fn->conditions[ix]->truev |= gcov_read_counter ();
> + fn->conditions[ix]->falsev |= gcov_read_counter ();
> + }
> + }
> + }
> else if (tag == GCOV_TAG_FOR_COUNTER (GCOV_COUNTER_ARCS) && fn)
> {
> length = abs (read_length);
> @@ -2443,6 +2567,15 @@ add_branch_counts (coverage_info *coverage, const arc_info *arc)
> }
> }
>
> +/* Increment totals in COVERAGE according to to block BLOCK. */
> +
> +static void
> +add_condition_counts (coverage_info *coverage, const block_info *block)
> +{
> + coverage->conditions += 2 * block->conditions.n_terms;
> + coverage->conditions_covered += block->conditions.popcount ();
> +}
> +
> /* Format COUNT, if flag_human_readable_numbers is set, return it human
> readable format. */
>
> @@ -2546,6 +2679,18 @@ file_summary (const coverage_info *coverage)
> coverage->calls);
> else
> fnotice (stdout, "No calls\n");
> +
> + }
> +
> + if (flag_conditions)
> + {
> + if (coverage->conditions)
> + fnotice (stdout, "Condition outcomes covered:%s of %d\n",
> + format_gcov (coverage->conditions_covered,
> + coverage->conditions, 2),
> + coverage->conditions);
> + else
> + fnotice (stdout, "No conditions\n");
> }
> }
>
> @@ -2780,6 +2925,12 @@ static void accumulate_line_info (line_info *line, source_info *src,
> it != line->branches.end (); it++)
> add_branch_counts (&src->coverage, *it);
>
> + if (add_coverage)
> + for (vector<block_info *>::iterator it = line->blocks.begin ();
> + it != line->blocks.end (); it++)
> + add_condition_counts (&src->coverage, *it);
> +
> +
> if (!line->blocks.empty ())
> {
> /* The user expects the line count to be the number of times
> @@ -2881,6 +3032,37 @@ accumulate_line_counts (source_info *src)
> }
> }
>
> +/* Output information about the conditions in block BINFO. The output includes
> + * a summary (n/m outcomes covered) and a list of the missing (uncovered)
> + * outcomes. */
> +
> +static void
> +output_conditions (FILE *gcov_file, const block_info *binfo)
> +{
> + const condition_info& info = binfo->conditions;
> + if (info.n_terms == 0)
> + return;
> +
> + const int expected = 2 * info.n_terms;
> + const int got = info.popcount ();
> +
> + fnotice (gcov_file, "condition outcomes covered %d/%d\n", got, expected);
> + if (expected == got)
> + return;
> +
> + for (unsigned i = 0; i < info.n_terms; i++)
> + {
> + gcov_type_unsigned index = 1;
> + index <<= i;
> + if ((index & info.truev & info.falsev))
> + continue;
> +
> + const char *t = (index & info.truev) ? "" : "true";
> + const char *f = (index & info.falsev) ? "" : " false";
> + fnotice (gcov_file, "condition %2u not covered (%s%s)\n", i, t, f + !t[0]);
> + }
> +}
> +
> /* Output information about ARC number IX. Returns nonzero if
> anything is output. */
>
> @@ -3091,16 +3273,29 @@ output_line_details (FILE *f, const line_info *line, unsigned line_num)
> if (flag_branches)
> for (arc = (*it)->succ; arc; arc = arc->succ_next)
> jx += output_branch_count (f, jx, arc);
> +
> + if (flag_conditions)
> + output_conditions (f, *it);
> }
> }
> - else if (flag_branches)
> + else
> {
> - int ix;
> + if (flag_branches)
> + {
> + int ix;
> +
> + ix = 0;
> + for (vector<arc_info *>::const_iterator it = line->branches.begin ();
> + it != line->branches.end (); it++)
> + ix += output_branch_count (f, ix, (*it));
> + }
>
> - ix = 0;
> - for (vector<arc_info *>::const_iterator it = line->branches.begin ();
> - it != line->branches.end (); it++)
> - ix += output_branch_count (f, ix, (*it));
> + if (flag_conditions)
> + {
> + for (vector<block_info *>::const_iterator it = line->blocks.begin ();
> + it != line->blocks.end (); it++)
> + output_conditions (f, *it);
> + }
> }
> }
>
> diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
> index 342e43a7f25..c72d7eb02e3 100644
> --- a/gcc/gimplify.cc
> +++ b/gcc/gimplify.cc
> @@ -71,6 +71,28 @@ along with GCC; see the file COPYING3. If not see
> #include "context.h"
> #include "tree-nested.h"
>
> +/* Identifier for a basic condition, mapping it to other basic conditions of
> + its Boolean expression. Basic conditions given the same uid (in the same
> + function) are parts of the same ANDIF/ORIF expression. Used for condition
> + coverage. */
> +static unsigned nextuid = 1;
> +/* Get a fresh identifier for a new condition expression. This is used for
> + condition coverage. */
> +static unsigned
> +next_cond_uid ()
> +{
> + return nextuid++;
> +}
> +/* Reset the condition uid to the value it should have when compiling a new
> + function. 0 is already the default/untouched value, so start at non-zero.
> + A valid and set id should always be > 0. This is used for condition
> + coverage. */
> +static void
> +reset_cond_uid ()
> +{
> + nextuid = 1;
> +}
> +
> /* Hash set of poisoned variables in a bind expr. */
> static hash_set<tree> *asan_poisoned_variables = NULL;
>
> @@ -4131,13 +4153,16 @@ gimplify_call_expr (tree *expr_p, gimple_seq *pre_p, bool want_value)
>
> LOCUS is the source location of the COND_EXPR.
>
> + The condition_uid is a discriminator tag for condition coverage used to map
> + conditions to its corresponding full Boolean function.
> +
> This function is the tree equivalent of do_jump.
>
> shortcut_cond_r should only be called by shortcut_cond_expr. */
>
> static tree
> shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p,
> - location_t locus)
> + location_t locus, unsigned condition_uid)
> {
> tree local_label = NULL_TREE;
> tree t, expr = NULL;
> @@ -4159,13 +4184,14 @@ shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p,
> false_label_p = &local_label;
>
> /* Keep the original source location on the first 'if'. */
> - t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p, locus);
> + t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p, locus,
> + condition_uid);
> append_to_statement_list (t, &expr);
>
> /* Set the source location of the && on the second 'if'. */
> new_locus = rexpr_location (pred, locus);
> t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p, false_label_p,
> - new_locus);
> + new_locus, condition_uid);
> append_to_statement_list (t, &expr);
> }
> else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
> @@ -4182,13 +4208,14 @@ shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p,
> true_label_p = &local_label;
>
> /* Keep the original source location on the first 'if'. */
> - t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL, locus);
> + t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL, locus,
> + condition_uid);
> append_to_statement_list (t, &expr);
>
> /* Set the source location of the || on the second 'if'. */
> new_locus = rexpr_location (pred, locus);
> t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p, false_label_p,
> - new_locus);
> + new_locus, condition_uid);
> append_to_statement_list (t, &expr);
> }
> else if (TREE_CODE (pred) == COND_EXPR
> @@ -4211,9 +4238,11 @@ shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p,
> new_locus = rexpr_location (pred, locus);
> expr = build3 (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
> shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
> - false_label_p, locus),
> + false_label_p, locus, condition_uid),
> shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
> - false_label_p, new_locus));
> + false_label_p, new_locus,
> + condition_uid));
> + SET_EXPR_UID (expr, condition_uid);
> }
> else
> {
> @@ -4221,6 +4250,7 @@ shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p,
> build_and_jump (true_label_p),
> build_and_jump (false_label_p));
> SET_EXPR_LOCATION (expr, locus);
> + SET_EXPR_UID (expr, condition_uid);
> }
>
> if (local_label)
> @@ -4271,12 +4301,44 @@ find_goto_label (tree expr)
> return NULL_TREE;
> }
>
> +
> +/* Given a multi-term condition (ANDIF, ORIF), walk the predicate PRED and tag
> + every basic condition with CONDITION_UID. Two basic conditions share the
> + CONDITION_UID discriminator when they belong to the same predicate, which is
> + used by the condition coverage. Doing this as an explicit step makes for a
> + simpler implementation than weaving it into the splitting code as the
> + splitting code eventually calls the entry point gimplfiy_expr which makes
> + bookkeeping complicated. */
> +static void
> +tag_shortcut_cond (tree pred, unsigned condition_uid)
> +{
> + if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR
> + || TREE_CODE (pred) == TRUTH_ORIF_EXPR)
> + {
> + tree fst = TREE_OPERAND (pred, 0);
> + tree lst = TREE_OPERAND (pred, 1);
> +
> + if (TREE_CODE (fst) == TRUTH_ANDIF_EXPR
> + || TREE_CODE (fst) == TRUTH_ORIF_EXPR)
> + tag_shortcut_cond (fst, condition_uid);
> + else if (TREE_CODE (fst) == COND_EXPR)
> + SET_EXPR_UID (fst, condition_uid);
> +
> + if (TREE_CODE (lst) == TRUTH_ANDIF_EXPR
> + || TREE_CODE (lst) == TRUTH_ORIF_EXPR)
> + tag_shortcut_cond (lst, condition_uid);
> + else if (TREE_CODE (lst) == COND_EXPR)
> + SET_EXPR_UID (lst, condition_uid);
> + }
> +}
> +
> /* Given a conditional expression EXPR with short-circuit boolean
> predicates using TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR, break the
> - predicate apart into the equivalent sequence of conditionals. */
> -
> + predicate apart into the equivalent sequence of conditionals. CONDITION_UID
> + is a the tag/discriminator for this EXPR - all basic conditions in the
> + expression will be given the same CONDITION_UID. */
> static tree
> -shortcut_cond_expr (tree expr)
> +shortcut_cond_expr (tree expr, unsigned condition_uid)
> {
> tree pred = TREE_OPERAND (expr, 0);
> tree then_ = TREE_OPERAND (expr, 1);
> @@ -4288,6 +4350,8 @@ shortcut_cond_expr (tree expr)
> bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
> bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
>
> + tag_shortcut_cond (pred, condition_uid);
> +
> /* First do simple transformations. */
> if (!else_se)
> {
> @@ -4303,7 +4367,7 @@ shortcut_cond_expr (tree expr)
> /* Set the source location of the && on the second 'if'. */
> if (rexpr_has_location (pred))
> SET_EXPR_LOCATION (expr, rexpr_location (pred));
> - then_ = shortcut_cond_expr (expr);
> + then_ = shortcut_cond_expr (expr, condition_uid);
> then_se = then_ && TREE_SIDE_EFFECTS (then_);
> pred = TREE_OPERAND (pred, 0);
> expr = build3 (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
> @@ -4325,7 +4389,7 @@ shortcut_cond_expr (tree expr)
> /* Set the source location of the || on the second 'if'. */
> if (rexpr_has_location (pred))
> SET_EXPR_LOCATION (expr, rexpr_location (pred));
> - else_ = shortcut_cond_expr (expr);
> + else_ = shortcut_cond_expr (expr, condition_uid);
> else_se = else_ && TREE_SIDE_EFFECTS (else_);
> pred = TREE_OPERAND (pred, 0);
> expr = build3 (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
> @@ -4333,6 +4397,9 @@ shortcut_cond_expr (tree expr)
> }
> }
>
> + /* The expr tree should also have the expression id set. */
> + SET_EXPR_UID (expr, condition_uid);
> +
> /* If we're done, great. */
> if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
> && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
> @@ -4380,7 +4447,7 @@ shortcut_cond_expr (tree expr)
> /* If there was nothing else in our arms, just forward the label(s). */
> if (!then_se && !else_se)
> return shortcut_cond_r (pred, true_label_p, false_label_p,
> - EXPR_LOC_OR_LOC (expr, input_location));
> + EXPR_LOC_OR_LOC (expr, input_location), condition_uid);
>
> /* If our last subexpression already has a terminal label, reuse it. */
> if (else_se)
> @@ -4412,7 +4479,8 @@ shortcut_cond_expr (tree expr)
> jump_over_else = block_may_fallthru (then_);
>
> pred = shortcut_cond_r (pred, true_label_p, false_label_p,
> - EXPR_LOC_OR_LOC (expr, input_location));
> + EXPR_LOC_OR_LOC (expr, input_location),
> + condition_uid);
>
> expr = NULL;
> append_to_statement_list (pred, &expr);
> @@ -4586,6 +4654,24 @@ generic_expr_could_trap_p (tree expr)
> return false;
> }
>
> +/* Associate the condition STMT with the discriminator UID. STMTs that are
> + broken down with ANDIF/ORIF from the same Boolean expression should be given
> + the same UID; 'if (a && b && c) { if (d || e) ... } ...' should yield the
> + { a: 1, b: 1, c: 1, d: 2, e: 2 } when gimplification is done. This is used
> + for condition coverage. */
> +static void
> +gimple_associate_condition_with_expr (struct function *fn, gcond *stmt,
> + unsigned uid)
> +{
> + if (!condition_coverage_flag)
> + return;
> +
> + if (!fn->cond_uids)
> + fn->cond_uids = new hash_map <gcond*, unsigned> ();
> +
> + fn->cond_uids->put (stmt, uid);
> +}
> +
> /* Convert the conditional expression pointed to by EXPR_P '(p) ? a : b;'
> into
>
> @@ -4688,7 +4774,7 @@ gimplify_cond_expr (tree *expr_p, gimple_seq *pre_p, fallback_t fallback)
> if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
> || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
> {
> - expr = shortcut_cond_expr (expr);
> + expr = shortcut_cond_expr (expr, next_cond_uid ());
>
> if (expr != *expr_p)
> {
> @@ -4752,11 +4838,16 @@ gimplify_cond_expr (tree *expr_p, gimple_seq *pre_p, fallback_t fallback)
> else
> label_false = create_artificial_label (UNKNOWN_LOCATION);
>
> + unsigned cond_uid = EXPR_COND_UID (expr);
> + if (cond_uid == 0)
> + cond_uid = next_cond_uid ();
> +
> gimple_cond_get_ops_from_tree (COND_EXPR_COND (expr), &pred_code, &arm1,
> &arm2);
> cond_stmt = gimple_build_cond (pred_code, arm1, arm2, label_true,
> label_false);
> gimple_set_location (cond_stmt, EXPR_LOCATION (expr));
> + gimple_associate_condition_with_expr (cfun, cond_stmt, cond_uid);
> copy_warning (cond_stmt, COND_EXPR_COND (expr));
> gimplify_seq_add_stmt (&seq, cond_stmt);
> gimple_stmt_iterator gsi = gsi_last (seq);
> @@ -18176,6 +18267,8 @@ gimplify_function_tree (tree fndecl)
> else
> push_struct_function (fndecl);
>
> + reset_cond_uid ();
> +
> /* Tentatively set PROP_gimple_lva here, and reset it in gimplify_va_arg_expr
> if necessary. */
> cfun->curr_properties |= PROP_gimple_lva;
> diff --git a/gcc/ipa-inline.cc b/gcc/ipa-inline.cc
> index dc120e6da5a..9502a21c741 100644
> --- a/gcc/ipa-inline.cc
> +++ b/gcc/ipa-inline.cc
> @@ -682,7 +682,7 @@ can_early_inline_edge_p (struct cgraph_edge *e)
> }
> gcc_assert (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->caller->decl))
> && gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)));
> - if (profile_arc_flag
> + if ((profile_arc_flag || condition_coverage_flag)
> && ((lookup_attribute ("no_profile_instrument_function",
> DECL_ATTRIBUTES (caller->decl)) == NULL_TREE)
> != (lookup_attribute ("no_profile_instrument_function",
> diff --git a/gcc/ipa-split.cc b/gcc/ipa-split.cc
> index 6730f4f9d0e..ca3bd5e3529 100644
> --- a/gcc/ipa-split.cc
> +++ b/gcc/ipa-split.cc
> @@ -1930,7 +1930,7 @@ pass_split_functions::gate (function *)
> /* When doing profile feedback, we want to execute the pass after profiling
> is read. So disable one in early optimization. */
> return (flag_partial_inlining
> - && !profile_arc_flag && !flag_branch_probabilities);
> + && !profile_arc_flag && !flag_branch_probabilities);
> }
>
> } // anon namespace
> diff --git a/gcc/passes.cc b/gcc/passes.cc
> index 087aed52934..110a6b0b174 100644
> --- a/gcc/passes.cc
> +++ b/gcc/passes.cc
> @@ -352,7 +352,8 @@ finish_optimization_passes (void)
> gcc::dump_manager *dumps = m_ctxt->get_dumps ();
>
> timevar_push (TV_DUMP);
> - if (profile_arc_flag || flag_test_coverage || flag_branch_probabilities)
> + if (profile_arc_flag || condition_coverage_flag || flag_test_coverage
> + || flag_branch_probabilities)
> {
> dumps->dump_start (pass_profile_1->static_pass_number, NULL);
> end_branch_prob ();
> diff --git a/gcc/profile.cc b/gcc/profile.cc
> index fc59326a19b..bff3b96d871 100644
> --- a/gcc/profile.cc
> +++ b/gcc/profile.cc
> @@ -69,6 +69,17 @@ along with GCC; see the file COPYING3. If not see
>
> #include "profile.h"
>
> +struct condcov;
> +struct condcov *find_conditions (struct function*);
> +size_t cov_length (const struct condcov*);
> +array_slice<basic_block> cov_blocks (struct condcov*, size_t);
> +array_slice<uint64_t> cov_masks (struct condcov*, size_t);
> +array_slice<sbitmap> cov_maps (struct condcov* cov, size_t n);
> +void cov_free (struct condcov*);
> +size_t instrument_decisions (array_slice<basic_block>, size_t,
> + array_slice<sbitmap>,
> + array_slice<gcov_type_unsigned>);
> +
> /* Map from BBs/edges to gcov counters. */
> vec<gcov_type> bb_gcov_counts;
> hash_map<edge,gcov_type> *edge_gcov_counts;
> @@ -100,6 +111,7 @@ static int total_num_passes;
> static int total_num_times_called;
> static int total_hist_br_prob[20];
> static int total_num_branches;
> +static int total_num_conds;
>
> /* Forward declarations. */
> static void find_spanning_tree (struct edge_list *);
> @@ -1155,6 +1167,12 @@ read_thunk_profile (struct cgraph_node *node)
> the flow graph that are needed to reconstruct the dynamic behavior of the
> flow graph. This data is written to the gcno file for gcov.
>
> + When FLAG_PROFILE_CONDITIONS is nonzero, this functions instruments the
> + edges in the control flow graph to track what conditions are evaluated to in
> + order to determine what conditions are covered and have an independent
> + effect on the outcome (modified condition/decision coverage). This data is
> + written to the gcno file for gcov.
> +
> When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
> information from the gcda file containing edge count information from
> previous executions of the function being compiled. In this case, the
> @@ -1173,6 +1191,7 @@ branch_prob (bool thunk)
> struct edge_list *el;
> histogram_values values = histogram_values ();
> unsigned cfg_checksum, lineno_checksum;
> + bool output_to_file;
>
> total_num_times_called++;
>
> @@ -1397,10 +1416,18 @@ branch_prob (bool thunk)
>
> /* Write the data from which gcov can reconstruct the basic block
> graph and function line numbers (the gcno file). */
> + output_to_file = false;
> if (coverage_begin_function (lineno_checksum, cfg_checksum))
> {
> gcov_position_t offset;
>
> + /* The condition coverage needs a deeper analysis to identify expressions
> + of conditions, which means it is not yet ready to write to the gcno
> + file. It will write its entries later, but needs to know if it do it
> + in the first place, which is controlled by the return value of
> + coverage_begin_function. */
> + output_to_file = true;
> +
> /* Basic block flags */
> offset = gcov_write_tag (GCOV_TAG_BLOCKS);
> gcov_write_unsigned (n_basic_blocks_for_fn (cfun));
> @@ -1514,29 +1541,65 @@ branch_prob (bool thunk)
>
> remove_fake_edges ();
>
> + if (condition_coverage_flag || profile_arc_flag)
> + gimple_init_gcov_profiler ();
> +
> + if (condition_coverage_flag)
> + {
> + struct condcov *cov = find_conditions (cfun);
> + gcc_assert (cov);
> + const size_t nconds = cov_length (cov);
> + total_num_conds += nconds;
> +
> + if (coverage_counter_alloc (GCOV_COUNTER_CONDS, 2 * nconds))
> + {
> + gcov_position_t offset {};
> + if (output_to_file)
> + offset = gcov_write_tag (GCOV_TAG_CONDS);
> +
> + for (size_t i = 0; i != nconds; ++i)
> + {
> + array_slice<basic_block> expr = cov_blocks (cov, i);
> + array_slice<uint64_t> masks = cov_masks (cov, i);
> + array_slice<sbitmap> maps = cov_maps (cov, i);
> + gcc_assert (expr.is_valid ());
> + gcc_assert (masks.is_valid ());
> + gcc_assert (maps.is_valid ());
> +
> + size_t terms = instrument_decisions (expr, i, maps, masks);
> + if (output_to_file)
> + {
> + gcov_write_unsigned (expr.front ()->index);
> + gcov_write_unsigned (terms);
> + }
> + }
> + if (output_to_file)
> + gcov_write_length (offset);
> + }
> + cov_free (cov);
> + }
> +
> /* For each edge not on the spanning tree, add counting code. */
> if (profile_arc_flag
> && coverage_counter_alloc (GCOV_COUNTER_ARCS, num_instrumented))
> {
> unsigned n_instrumented;
>
> - gimple_init_gcov_profiler ();
> -
> n_instrumented = instrument_edges (el);
>
> gcc_assert (n_instrumented == num_instrumented);
>
> if (flag_profile_values)
> instrument_values (values);
> -
> - /* Commit changes done by instrumentation. */
> - gsi_commit_edge_inserts ();
> }
>
> free_aux_for_edges ();
>
> values.release ();
> free_edge_list (el);
> + /* Commit changes done by instrumentation. */
> + gsi_commit_edge_inserts ();
> +
> coverage_end_function (lineno_checksum, cfg_checksum);
> if (flag_branch_probabilities
> && (profile_status_for_fn (cfun) == PROFILE_READ))
> @@ -1669,6 +1732,7 @@ init_branch_prob (void)
> total_num_passes = 0;
> total_num_times_called = 0;
> total_num_branches = 0;
> + total_num_conds = 0;
> for (i = 0; i < 20; i++)
> total_hist_br_prob[i] = 0;
> }
> @@ -1708,5 +1772,7 @@ end_branch_prob (void)
> (total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100
> / total_num_branches, 5*i, 5*i+5);
> }
> + fprintf (dump_file, "Total number of conditions: %d\n",
> + total_num_conds);
> }
> }
> diff --git a/gcc/testsuite/g++.dg/gcov/gcov-18.C b/gcc/testsuite/g++.dg/gcov/gcov-18.C
> new file mode 100644
> index 00000000000..620aef12699
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/gcov/gcov-18.C
> @@ -0,0 +1,282 @@
> +/* { dg-options "--coverage -fcondition-coverage -std=c++11" } */
> +/* { dg-do run { target native } } */
> +
> +#include <vector>
> +#include <stdexcept>
> +
> +class nontrivial_destructor
> +{
> +public:
> + explicit nontrivial_destructor (int v) : val (v) {}
> + ~nontrivial_destructor () {}
> +
> + explicit operator bool() const { return bool(val); }
> +
> + int val;
> +};
> +
> +int identity (int x) { return x; }
> +int throws (int) { throw std::runtime_error("exception"); }
> +
> +int
> +throw_if (int x)
> +{
> + if (x) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + throw std::runtime_error("exception");
> + return x;
> +}
> +
> +/* Used for side effects to insert nodes in conditional bodies etc. */
> +int x = 0;
> +
> +/* Conditionals work in the presence of non-trivial destructors. */
> +void
> +mcdc001a (int a)
> +{
> + nontrivial_destructor v (a);
> +
> + if (v.val > 0) /* conditions(2/2) */
> + x = v.val;
> + else
> + x = -v.val;
> +}
> +
> +/* Non-trivial destructor in-loop temporary. */
> +nontrivial_destructor
> +mcdc002a (int a, int b)
> +{
> + for (int i = 0; i < a; i++) /* conditions(2/2) */
> + {
> + nontrivial_destructor tmp (a);
> + if (tmp.val % b) /* conditions(2/2) */
> + return nontrivial_destructor (0);
> + x += i;
> + } /* conditions(suppress) */
> + /* conditions(end) */
> +
> + return nontrivial_destructor (a * b);
> +}
> +
> +/* Conditional in constructor. */
> +void
> +mcdc003a (int a)
> +{
> + class C
> + {
> + public:
> + explicit C (int e) : v (e)
> + {
> + if (e) /* conditions(1/2) false(0) */
> + v = x - e;
> + }
> + int v;
> + };
> +
> + C c (a);
> + if (c.v > 2) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + x = c.v + a;
> +}
> +
> +/* Conditional in destructor. */
> +void
> +mcdc004a (int a)
> +{
> + class C
> + {
> + public:
> + explicit C (int e) : v (e) {}
> + ~C ()
> + {
> + if (v) /* conditions(2/2) */
> + x = 2 * v;
> + }
> + int v;
> + };
> +
> + C c (a);
> + x = 1; // arbitrary action between ctor+dtor
> +}
> +
> +/* Conditional in try. */
> +void
> +mcdc005a (int a)
> +{
> + try
> + {
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + x = 2 * identity (a);
> + else
> + x = 1;
> + }
> + catch (...)
> + {
> + x = 0;
> + }
> +}
> +
> +/* Conditional in catch. */
> +void
> +mcdc006a (int a) {
> + try
> + {
> + throws (a);
> + }
> + catch (std::exception&)
> + {
> + if (a) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + x = identity (a);
> + else
> + x = 0;
> + }
> +}
> +
> +void
> +mcdc006b (int a)
> +{
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + throws (a);
> + else
> + x = 1;
> +}
> +
> +void
> +mcdc006c (int a) try
> +{
> + throws (a);
> +}
> +catch (...) {
> + if (a) /* conditions(2/2) */
> + x = 5;
> +}
> +
> +/* Temporary with destructor as term. */
> +void
> +mcdc007a (int a, int b)
> +{
> + x = a && nontrivial_destructor (b); /* conditions(3/4) false(1) destructor() */
> +}
> +
> +void
> +mcdc007b (int a, int b)
> +{
> + if (a || throw_if (b)) /* conditions(3/4) true(1) destructor() */
> + x = -1;
> + else
> + x = 1;
> +}
> +
> +void
> +mcdc007c (int a, int b)
> +{
> + if (throw_if (a) || throw_if (b)) /* conditions(2/4) true(0 1) destructor() */
> + x = -1;
> + else
> + x = 1;
> +}
> +
> +/* Destructor with delete. */
> +void
> +mcdc008a (int a)
> +{
> + class C
> + {
> + public:
> + int size = 5;
> + int* ptr = nullptr;
> +
> + explicit C (int v) : size (v + 5), ptr (new int[size]) /* conditions(suppress) */
> + /* conditions(end) */
> + {
> + for (int i = 0; i < size; i++) /* conditions(2/2) */
> + ptr[i] = i + 1;
> + }
> + ~C()
> + {
> + // delete with implicit nullptr check
> + delete ptr; /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + }
> + };
> +
> + C c (a);
> + if (c.ptr[a + 1]) /* conditions(1/2) false(0) */
> + x = a;
> +}
> +
> +/* Templates. */
> +template <typename T>
> +void
> +mcdc009a (T a)
> +{
> + if (a > 0) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + x += 2;
> +}
> +
> +/* constexpr. */
> +
> +/* Compile-time evaluated branches do not contribute to coverage. */
> +constexpr int
> +mcdc010a (int a, int b)
> +{
> + return a > b ? 1 : 2; /* conditions(1/2) true(0) */
> + /* conditions(end) */
> +}
> +
> +/* Compile-time only evaluated functions do not show up in the compiled program
> + and gets no coverage at all. If this would generate output unexpectedly it
> + would trigger a test failure ("unexpected output"). */
> +constexpr int
> +mcdc010b (int a, int b)
> +{
> + return a > b ? 1 : 2;
> +}
> +
> +int
> +main (void)
> +{
> + mcdc001a (0);
> + mcdc001a (1);
> +
> + mcdc002a (1, 1);
> + mcdc002a (1, 2);
> +
> + mcdc003a (1);
> +
> + mcdc004a (0);
> + mcdc004a (1);
> +
> + mcdc005a (0);
> +
> + mcdc006a (1);
> +
> + mcdc006b (0);
> +
> + mcdc006c (0);
> + mcdc006c (1);
> +
> + mcdc007a (0, 0);
> + mcdc007a (1, 1);
> +
> + mcdc007b (0, 0);
> + mcdc007b (1, 0);
> +
> + mcdc007c (0, 0);
> +
> + mcdc008a (1);
> +
> + mcdc009a (1);
> +
> + /* Use identity () so that this is not constexpr eval'd. */
> + int v1 = mcdc010a (identity (2), 4);
> + constexpr int v2 = mcdc010a (4, 2);
> +
> + constexpr int v3 = mcdc010b (2, 4);
> +}
> +
> +/* { dg-final { run-gcov conditions { --conditions gcov-18.C } } } */
> diff --git a/gcc/testsuite/gcc.misc-tests/gcov-19.c b/gcc/testsuite/gcc.misc-tests/gcov-19.c
> new file mode 100644
> index 00000000000..17f1fb4e923
> --- /dev/null
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-19.c
> @@ -0,0 +1,1737 @@
> +/* { dg-options "-fcondition-coverage -ftest-coverage" } */
> +/* { dg-do run { target native } } */
> +
> +/* Some side effect to stop branches from being pruned. */
> +int x = 0;
> +
> +int id (int x) { return x; }
> +int inv (int x) { return !x; }
> +
> +/* || works. */
> +void
> +mcdc001a (int a, int b)
> +{
> + if (a || b) /* conditions(1/4) true(0) false(0 1) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc001b (int a, int b)
> +{
> + if (a || b) /* conditions(3/4) true(0) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc001c (int a, int b)
> +{
> + if (a || b) /* conditions(4/4) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc001d (int a, int b, int c)
> +{
> + if (a || b || c) /* conditions(2/6) false(0 1 2) true(2) */
> + /* conditions(end) */
> + x = 1;
> +}
> +
> +/* && works */
> +void
> +mcdc002a (int a, int b)
> +{
> + if (a && b) /* conditions(1/4) true(0 1) false(0) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc002b (int a, int b)
> +{
> + if (a && b) /* conditions(3/4) false(0) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc002c (int a, int b)
> +{
> + if (a && b) /* conditions(4/4) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc002d (int a, int b, int c)
> +{
> + if (a && b && c) /* conditions(4/6) false(0 2) */
> + /* conditions(end) */
> + x = 1;
> +}
> +
> +/* Negation works. */
> +void
> +mcdc003a (int a, int b)
> +{
> + if (!a || !b) /* conditions(2/4) false(0 1) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +/* Single conditionals with and without else. */
> +void
> +mcdc004a (int a)
> +{
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc004b (int a)
> +{
> + if (a) /* conditions(2/2) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc004c (int a)
> +{
> + if (a) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + x = 1;
> +}
> +
> +void
> +mcdc004d (int a, int b, int c)
> +{
> + if (a) /* conditions(2/2) */
> + {
> + if (b || c) /* conditions(1/4) true(1) false(0 1) */
> + x = a + b + c;
> + }
> +}
> +
> +void
> +mcdc004e (int a, int b, int c)
> +{
> + if (a) /* conditions(2/2) */
> + {
> + if (b || c) /* conditions(1/4) true(1) false(0 1) */
> + /* conditions(end) */
> + x = a + b + c;
> + }
> + else
> + {
> + x = c;
> + }
> +}
> +
> +void
> +mcdc004f (int a, int b, int c)
> +{
> + if (a) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + {
> + x = 1;
> + }
> + else if (b) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + x = 2;
> + if (c) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + x = 3;
> + }
> +}
> +
> +/* mixing && and || works */
> +void
> +mcdc005a (int a, int b, int c)
> +{
> + if ((a && b) || c) /* conditions(1/6) true(0 1) false(0 1 2) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc005b (int a, int b, int c, int d)
> +{
> + /* This is where masking MC/DC gets unintuitive:
> +
> + 1 1 0 0 => covers 1 (d = 0) as && 0 masks everything to the left
> + 1 0 0 0 => covers 2 (b = 0, c = 0) as (a && 0) masks a and d is never
> + evaluated. */
> + if ((a && (b || c)) && d) /* conditions(3/8) true(0 1 2 3) false(0) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc005c (int a, int b, int c, int d)
> +{
> + if (a || (b && c) || d) /* conditions(2/8) true(0 3) false(0 1 2 3) */
> + /* conditions(end) */
> + x = a + b + c + d;
> +}
> +
> +void
> +mcdc005d (int a, int b, int c, int d)
> +{
> + /* This test is quite significant - it has a single input
> + (1, 0, 0, 0) and tests specifically for when a multi-term left operand
> + is masked. d = 0 should mask a || b and for the input there are no other
> + sources for masking a (since b = 0). */
> + if ((a || b) && (c || d)) /* conditions(2/8) true(0 1 2 3) false(0 1) */
> + /* conditions(end) */
> + x = a + b;
> + else
> + x = c + d;
> +}
> +
> +/* Mixing in constants kills the decision removes the term outright. */
> +void
> +mcdc005e (int a, int b)
> +{
> + x += 0 && a;
> + x += a && 1;
> + x += 0 && a && b;
> + x += a && 1 && b; /* conditions(4/4) */
> + x += a && b && 0;
> + x += 0 && 1;
> + x += 1 && a;
> + x += a && 0;
> + x += 1 || a;
> + x += a || 0;
> + x += 1 || a || b;
> + x += a || 0 || b; /* conditions(4/4) */
> + x += a || b || 1;
> + x += 1 || 0;
> + x += 0 || a;
> + x += a || 1;
> +}
> +
> +/* Nested conditionals. */
> +void
> +mcdc006a (int a, int b, int c, int d, int e)
> +{
> + if (a) /* conditions(2/2) */
> + {
> + if (b && c) /* conditions(3/4) false(1) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> + }
> + else
> + {
> + if (c || d) /* conditions(2/4) true(0 1) */
> + /* conditions(end) */
> + x = 3;
> + else
> + x = 4;
> + }
> +}
> +
> +void
> +mcdc006b (int a, int b, int c)
> +{
> + if (a) /* conditions(2/2) */
> + if (b) /* conditions(2/2) */
> + if (c) /* conditions(2/2) */
> + x = a + b + c;
> +}
> +
> +void
> +mcdc006c (int a, int b, int c)
> +{
> + if (a) /* conditions(2/2) */
> + {
> + if (b) /*conditions(2/2) */
> + {
> + if (c) /* conditions(2/2) */
> + {
> + x = a + b + c;
> + }
> + }
> + else
> + {
> + x = b;
> + }
> + }
> + else
> + {
> + x = a;
> + }
> +}
> +
> +void
> +mcdc006d (int a, int b, int c)
> +{
> + if (a) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + {
> + if (b) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + x = a + b;
> + if (c) /* conditions(2/2) */
> + /* conditions(end) */
> + x = a + b;
> + }
> +}
> +
> +void
> +mcdc006e (int a, int b, int c, int d)
> +{
> + if ((a || b || c) && id (d)) /* conditions(4/8) true(0 1 2 3) false() */
> + /* conditions(end) */
> + x = 1;
> +}
> +
> +/* else/if. */
> +void
> +mcdc007a (int a, int b, int c, int d)
> +{
> + if (a) /* conditions(2/2) */
> + {
> + if (b) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> + }
> + else if (c) /* conditions(2/2) */
> + {
> + if (d) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + x = 3;
> + else
> + x = 4;
> + }
> +}
> +
> +void
> +mcdc007b (int a, int b, int c)
> +{
> + goto begin;
> +then:
> + x = 1;
> + return;
> +begin:
> + if (a) /* conditions(2/2) */
> + goto then;
> + else if (b) /* conditions(2/2) */
> + goto then;
> + else if (c) /* conditions(1/2) true(0) */
> + goto then;
> +}
> +
> +void
> +mcdc007c (int a, int b, int c)
> +{
> + goto begin;
> +then1:
> + x = 1;
> + return;
> +then2:
> + x = 1;
> + return;
> +then3:
> + x = 1;
> + return;
> +begin:
> + if (a) /* conditions(2/2) */
> + goto then1;
> + else if (b) /* conditions(2/2) */
> + goto then2;
> + else if (c) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + goto then3;
> +}
> +
> +void
> +noop () {}
> +
> +int
> +mcdc007d (int a, int b, int c, int d, int e)
> +{
> + noop ();
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + {
> + if (b || c) /* conditions(0/4) true(0 1) false(0 1) */
> + /* conditions(end) */
> + x = 2;
> + if (d) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return 1;
> + }
> + if (e) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + return 0;
> +
> + return 2;
> +}
> +
> +/* while loop. */
> +void
> +mcdc008a (int a)
> +{
> + while (a < 10) /* conditions(2/2) */
> + x = a++;
> +}
> +
> +void
> +mcdc008b (int a)
> +{
> + while (a > 10) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + x = a--;
> +}
> +
> +void
> +mcdc008c (int a)
> +{
> + // should work, even with no body
> + while (a) /* conditions(2/2) */
> + break;
> +}
> +
> +/* Multi-term loop conditional. */
> +void
> +mcdc008d (int a, int b, int c, int d)
> +{
> + while ((a && (b || c)) && d) /* conditions(8/8) */
> + a = b = c = d = 0;
> +}
> +
> +void
> +mcdc009a (int a, int b)
> +{
> + while (a > 0 && b > 0) /* conditions(3/4) false(1) */
> + /* conditions(end) */
> + x = a--;
> +}
> +
> +void
> +mcdc009b (int a, int b)
> +{
> + while (a-- > 0 && b) {} /* conditions(2/4) true(0 1) */
> + /* conditions(end) */
> +}
> +
> +/* for loop. */
> +void
> +mcdc010a (int a, int b)
> +{
> + for (int i = 0; i < b; i++) /* conditions(2/2) */
> + {
> + if (a < b) /* conditions(2/2) */
> + x = 1;
> + else
> + x = a += 2;
> + }
> +}
> +
> +void
> +mcdc010b ()
> +{
> + for (int a = 0; a <= 1; ++a) /* conditions(2/2) */
> + {
> + x = a;
> + }
> +}
> +
> +int
> +mcdc010c (int a, int b, int c)
> +{
> + for (;a || b || c;) /* conditions(4/6) true(0 2) */
> + /* conditions(end) */
> + return 1;
> + return 0;
> +}
> +
> +
> +int always (int x) { (void) x; return 1; }
> +
> +/* No-condition infinite loops. */
> +void
> +mcdc010d (int a)
> +{
> + for (;;)
> + {
> + if (always(a)) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + {
> + x = a;
> + break;
> + }
> + x += a + 1;
> + }
> +}
> +
> +/* Conditionals without control flow constructs work. */
> +void
> +mcdc011a (int a, int b, int c)
> +{
> + x = (a && b) || c; /* conditions(5/6) false(1) */
> + /* conditions(end) */
> +}
> +
> +/* Sequential expressions are handled independently. */
> +void
> +mcdc012a (int a, int b, int c)
> +{
> + if (a || b) /* conditions(3/4) true(0) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +
> + if (c) /* conditions(2/2) */
> + x = 1;
> +}
> +
> +/* Cannot ever satisfy (masking) MC/DC, even with all input combinations,
> + because not all variables independently affect the decision. */
> +void
> +mcdc013a (int a, int b, int c)
> +{
> + (void)b;
> + /* Specification: (a && b) || c
> + The implementation does not match the specification. This has branch
> + coverage, but not MC/DC. */
> + if ((a && !c) || c) /* conditions(5/6) false(1) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +void
> +mcdc014a ()
> +{
> + int conds[64] = { 0 };
> + /* conditions(64/128) true(0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63) */
> + x = conds[ 0] || conds[ 1] || conds[ 2] || conds[ 3] || conds[ 4] ||
> + conds[ 5] || conds[ 6] || conds[ 7] || conds[ 8] || conds[ 9] ||
> + conds[10] || conds[11] || conds[12] || conds[13] || conds[14] ||
> + conds[15] || conds[16] || conds[17] || conds[18] || conds[19] ||
> + conds[20] || conds[21] || conds[22] || conds[23] || conds[24] ||
> + conds[25] || conds[26] || conds[27] || conds[28] || conds[29] ||
> + conds[30] || conds[31] || conds[32] || conds[33] || conds[34] ||
> + conds[35] || conds[36] || conds[37] || conds[38] || conds[39] ||
> + conds[40] || conds[41] || conds[42] || conds[43] || conds[44] ||
> + conds[45] || conds[46] || conds[47] || conds[48] || conds[49] ||
> + conds[50] || conds[51] || conds[52] || conds[53] || conds[54] ||
> + conds[55] || conds[56] || conds[57] || conds[58] || conds[59] ||
> + conds[60] || conds[61] || conds[62] || conds[63]
> + ; /* conditions(end) */
> +}
> +
> +/* Early returns. */
> +void
> +mcdc015a (int a, int b)
> +{
> + if (a) /* conditions(2/2) */
> + return;
> +
> + if (b) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + x = 1;
> +}
> +
> +void
> +mcdc015b (int a, int b)
> +{
> + for (int i = 5; i > a; i--) /* conditions(2/2) */
> + {
> + if (i == b) /* conditions(2/2) */
> + return;
> + x = i;
> + }
> +}
> +
> +void
> +mcdc015c (int a, int b)
> +{
> + for (int i = 5; i > a; i--) /* conditions(2/2) */
> + {
> + if (i == b) /* conditions(2/2) */
> + {
> + x = 0;
> + return;
> + }
> + else
> + {
> + x = 1;
> + return;
> + }
> +
> + x = i;
> + }
> +}
> +
> +/* Early returns, gotos. */
> +void
> +mcdc015d (int a, int b, int c)
> +{
> + if (a) return; /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + if (id (b)) return; /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + if (id (c)) return; /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> +}
> +
> +
> +/* Nested loops. */
> +void
> +mcdc016a (int a, int b)
> +{
> + for (int i = 0; i < a; i++) /* conditions(2/2) */
> + for (int k = 0; k < b; k++) /* conditions(2/2) */
> + x = i + k;
> +}
> +
> +void
> +mcdc016b (int a, int b)
> +{
> + for (int i = 0; i < a; i++) /* conditions(2/2) */
> + {
> + if (a > 5) /* conditions(2/2) */
> + break;
> +
> + for (int k = 0; k < b; k++) /* conditions(2/2) */
> + x = i + k;
> + }
> +}
> +
> +void
> +mcdc016c (int a, int b)
> +{
> + for (int i = 0; i < a; i++) /* conditions(2/2) */
> + {
> + if (a > 5) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + return;
> +
> + for (int k = 0; k < b; k++) /* conditions(2/2) */
> + x = i + k;
> + }
> +}
> +
> +void
> +mcdc016d (int a, int b)
> +{
> + for (int i = 0; i < a; i++) /* conditions(2/2) */
> + {
> + for (int k = 0; k < 5; k++) /* conditions(2/2) */
> + {
> + if (b > 5) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + return;
> + x = i + k;
> + }
> +
> + }
> +}
> +
> +/* do-while loops */
> +void
> +mcdc017a (int a)
> +{
> + do
> + {
> + a--;
> + } while (a > 0); /* conditions(2/2) */
> +}
> +
> +void
> +mcdc017b (int a, int b)
> +{
> + do
> + {
> + /* This call is important; it can add more nodes to the body in the
> + CFG, which changes how close exits and breaks are to the loop
> + conditional. */
> + noop ();
> + a--;
> + if (b) /* conditions(2/2) */
> + break;
> +
> + } while (a > 0); /* conditions(2/2) */
> +}
> +
> +void
> +mcdc017c (int a, int b)
> +{
> + int left = 0;
> + int right = 0;
> + int n = a + b;
> + do
> + {
> + if (a) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + {
> + left = a > left ? b : left; /* conditions(2/2) */
> + }
> + if (b) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + {
> + right = b > right ? a : right; /* conditions(2/2) */
> + }
> + } while (n-- > 0); /* conditions(2/2) */
> +}
> +
> +void
> +mcdc017d (int a, int b, int c)
> +{
> + do
> + {
> + a--;
> + } while (a > 0 && b && c); /* conditions(0/6) true(0 1 2) false(0 1 2) */
> + /* conditions(end) */
> +}
> +
> +/* Collection of odd cases lifted-and-adapted from real-world code. */
> +int
> +mcdc018a (int a, int b, int c, int d, int e, int f, int g, int len)
> +{
> + int n;
> + /* adapted from zlib/gz_read */
> + do
> + {
> + n = -1;
> + if (n > len) /* conditions(2/2) */
> + n = len;
> +
> + if (b) /* conditions(2/2) */
> + {
> + if (b < 5) /* conditions(2/2) */
> + x = 1;
> + noop();
> + }
> + else if (c && d) /* conditions(3/4) false(1) */
> + /* conditions(end) */
> + {
> + x = 2;
> + break;
> + }
> + else if (e || f) /* conditions(2/4) false(0 1) */
> + /* conditions(end) */
> + {
> + if (id(g)) /* conditions(2/2) */
> + return 0;
> + continue;
> + }
> + } while (a-- > 0); /* conditions(2/2) */
> +
> + return 1;
> +}
> +
> +void
> +mcdc018b (int a, int b, int c)
> +{
> + int n;
> + while (a) /* conditions(2/2) */
> + {
> + /* else block does not make a difference for the problem, but ensures
> + loop termination. */
> + if (b) /* conditions(2/2) */
> + n = c ? 0 : 0; // does not show up in CFG (embedded in the block)
> + else
> + n = 0;
> + a = n;
> + }
> +}
> +
> +/* Adapted from zlib/compress2. */
> +void
> +mcdc018c (int a, int b)
> +{
> + int err;
> + do
> + {
> + a = inv (a);
> + err = a;
> + } while (err); /* conditions(1/2) true(0) */
> + /* conditions(end) */
> +
> + a = id (a);
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + x *= a + 1;
> +}
> +
> +/* Too many conditions, coverage gives up. */
> +void
> +mcdc019a ()
> +{
> + int conds[65] = { 0 };
> + #pragma GCC diagnostic push
> + #pragma GCC diagnostic ignored "-Wcoverage-too-many-conditions"
> + x = conds[ 0] || conds[ 1] || conds[ 2] || conds[ 3] || conds[ 4] ||
> + conds[ 5] || conds[ 6] || conds[ 7] || conds[ 8] || conds[ 9] ||
> + conds[10] || conds[11] || conds[12] || conds[13] || conds[14] ||
> + conds[15] || conds[16] || conds[17] || conds[18] || conds[19] ||
> + conds[20] || conds[21] || conds[22] || conds[23] || conds[24] ||
> + conds[25] || conds[26] || conds[27] || conds[28] || conds[29] ||
> + conds[30] || conds[31] || conds[32] || conds[33] || conds[34] ||
> + conds[35] || conds[36] || conds[37] || conds[38] || conds[39] ||
> + conds[40] || conds[41] || conds[42] || conds[43] || conds[44] ||
> + conds[45] || conds[46] || conds[47] || conds[48] || conds[49] ||
> + conds[50] || conds[51] || conds[52] || conds[53] || conds[54] ||
> + conds[55] || conds[56] || conds[57] || conds[58] || conds[59] ||
> + conds[60] || conds[61] || conds[62] || conds[63] || conds[64]
> + ;
> + #pragma GCC diagnostic pop
> +}
> +
> +/* Ternary. */
> +void
> +mcdc020a (int a)
> +{
> + // special case, this can be reduced to:
> + // _1 = argc != 0;
> + // e = (int) _1;
> + x = a ? 1 : 0;
> +
> + // changing to different int makes branch
> + x = a ? 2 : 1; /* conditions(2/2) */
> +}
> +
> +void
> +mcdc020b (int a, int b)
> +{
> + x = (a || b) ? 1 : 0; /* conditions(3/4) true(1) */
> + /* conditions(end) */
> +}
> +
> +void
> +mcdc020c (int a, int b)
> +{
> + x = a ? 0
> + : b ? 1 /* conditions(2/2) */
> + : 2; /* conditions(1/2) false(0) */
> + /* conditions(end) */
> +}
> +
> +int
> +mcdc020d (int b, int c, int d, int e, int f)
> +{
> + return ((b ? c : d) && e && f); /* conditions(7/10) true(2) false(3 4) */
> + /* conditions(end) */
> +}
> +
> +/* Infinite loop (no exit-edge), this should not be called, but it should
> + compile fine. */
> +void
> +mcdc021a ()
> +{
> + while (1)
> + ;
> +}
> +
> +/* Computed goto can give all sorts of problems, including difficult path
> + contractions. */
> +void
> +mcdc021b ()
> +{
> + void *op = &&dest;
> +dest:
> + if (op) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + goto * 0;
> +}
> +
> +int __sigsetjmp ();
> +
> +/* This should compile, but not called. */
> +void
> +mcdc021c ()
> +{
> + while (x) /* conditions(0/2) true(0) false(0)*/
> + /* conditions(end) */
> + __sigsetjmp ();
> +}
> +
> +/* If edges are not properly contracted the a && id (b) will be interpreted as
> + two independent expressions. */
> +void
> +mcdc021d (int a, int b, int c, int d)
> +{
> + if (a && id (b)) /* conditions(1/4) true(0 1) false(0) */
> + /* conditions(end) */
> + x = 1;
> + else if (c && id (d)) /* conditions(1/4) true(0 1) false(0) */
> + /* conditions(end) */
> + x = 2;
> + else
> + x = 3;
> +}
> +
> +/* Adapted from linux arch/x86/tools/relocs.c
> + With poor edge contracting this became an infinite loop. */
> +void
> +mcdc022a (int a, int b)
> +{
> + for (int i = 0; i < 5; i++) /* conditions(2/2) */
> + {
> + x = i;
> + for (int j = i; j < 5; j++) /* conditions(2/2) */
> + {
> + if (id (id (a)) || id (b)) /* conditions(3/4) true(0) */
> + /* conditions(end) */
> + continue;
> + b = inv(b);
> + }
> + }
> +}
> +
> +int
> +mcdc022b (int a)
> +{
> + int devt;
> + if (a) /* conditions(2/2) */
> + {
> + x = a * 2;
> + if (x != a / 10 || x != a % 10) /* conditions(1/4) true(1) false(0 1) */
> + /* conditions(end) */
> + return 0;
> + } else {
> + devt = id (a);
> + if (devt) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + return 0;
> + }
> +
> + return devt;
> +}
> +
> +/* Adapted from linux arch/x86/events/intel/ds.c
> +
> + It broken sorting so that the entry block was not the first node after
> + sorting. */
> +void
> +mcdc022c (int a)
> +{
> + if (!a) /* conditions(2/2) */
> + return;
> +
> + for (int i = 0; i < 5; i++) /* conditions(2/2) */
> + {
> + if (id (a + i) || inv (a - 1)) /* conditions(1/4) false(0 1) true(1) */
> + /* conditions(end) */
> + x = a + i;
> + if (inv (a)) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + break;
> + }
> +}
> +
> +void
> +mcdc022d (int a)
> +{
> + int i;
> + for (i = 0; i < id (a); i++) /* conditions(1/2) false(0) */
> + {
> + if (!inv (a)) /* conditions(1/2) false(0)*/
> + /* conditions(end) */
> + break;
> + }
> +
> + if (i < a) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + x = a + 1;
> +}
> +
> +/* Adapted from openssl-3.0.1/crypto/cmp/cmp_msg.c ossl_cmp_error_new (). */
> +void
> +mcdc022e (int a, int b, int c, int d)
> +{
> + if (a || b) /* conditions(1/4) true(0) false(0 1) */
> + /* conditions(end) */
> + {
> + if (always (c)) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + goto err;
> + d++;
> + }
> +
> + if (d) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + goto err;
> + return;
> +
> +err:
> + noop ();
> +}
> +
> +/* 023 specifically tests that masking works correctly, which gets complicated
> + fast with a mix of operators and deep subexpressions. These tests violates
> + the style guide slightly to emphasize the nesting. They all share the same
> + implementation and only one input is given to each function to obtain clean
> + coverage results. */
> +void
> +mcdc023a (int a, int b, int c, int d, int e, int f, int g, int h, int i, int k,
> + int l, int m, int n)
> +{
> + // [a m n] = 0, [b, ...] = 1
> + // a is masked by b and the remaining terms should be short circuited
> + if (/* conditions(1/24) true(0 2 3 4 5 6 7 8 9 10 11) false(0 1 2 3 4 5 6 7 8 9 10 11) */
> + /* conditions(end) */
> + (a || b)
> + || ( ((c && d) || (e && (f || g) && h))
> + && (k || l)
> + && (m || n)))
> + x = a + b;
> + else
> + x = b + c;
> +}
> +
> +void
> +mcdc023b (int a, int b, int c, int d, int e, int f, int g, int h, int i, int k,
> + int l, int m, int n)
> +{
> + // [a b d h] = 0, [c, ...] = 1
> + // h = 0 => false but does not mask (a || b) or (c && d). d = 0 masks c.
> + if (/* conditions(4/24) true(0 1 2 3 4 5 6 7 8 9 10 11) false(2 4 5 6 8 9 10 11) */
> + /* conditions(end) */
> + (a || b)
> + || ( ((c && d) || (e && (f || g) && h))
> + && (k || l)
> + && (m || n)))
> + x = a + b;
> + else
> + x = b + c;
> +}
> +
> +void
> +mcdc023c (int a, int b, int c, int d, int e, int f, int g, int h, int i, int k,
> + int l, int m, int n)
> +{
> + /* [m n a b] = 0, [...] = 1
> + n,m = 0 should mask all other terms than a, b */
> + if (/* conditions(4/24) true(0 1 2 3 4 5 6 7 8 9 10 11) false(2 3 4 5 6 7 8 9) */
> + /* conditions(end) */
> + (a || b)
> + || ( ((c && d) || (e && (f || g) && h))
> + && (k || l)
> + && (m || n)))
> + x = a + b;
> + else
> + x = b + c;
> +}
> +
> +void
> +mcdc023d (int a, int b, int c, int d, int e, int f, int g, int h, int i, int k,
> + int l, int m, int n)
> +{
> + /* [a b] = 0, [h, ...] = 1
> + n,m = 0 should mask all other terms than a, b */
> + if (/* conditions(4/24) true(0 1 2 3 4 5 6 7 8 9 10 11) false(2 3 4 5 6 7 10 11) */
> + /* conditions(end) */
> + (a || b)
> + || ( ((c && d) || (e && (f || g) && h))
> + && (k || l)
> + && (m || n)))
> + x = a + b;
> + else
> + x = b + c;
> +}
> +
> +void
> +mcdc023e (int a, int b, int c, int d, int e, int f, int g, int h, int i, int k,
> + int l, int m, int n)
> +{
> + /* [a b d] = 0, [c h, ...] = 1
> + h = 1 should mask c, d, leave other terms intact.
> + If [k l m n] were false then h itself would be masked.
> + [a b] are masked as collateral by [m n]. */
> + if (/* conditions(5/24) true(0 1 2 3 6 9 11) false(0 1 2 3 4 5 6 7 8 9 10 11) */
> + /* conditions(end) */
> + (a || b)
> + || ( ((c && d) || (e && (f || g) && h))
> + && (k || l)
> + && (m || n)))
> + x = a + b;
> + else
> + x = b + c;
> +}
> +
> +void
> +mcdc023f (int a, int b, int c, int d, int e, int f, int g, int h, int i, int k,
> + int l, int m, int n)
> +{
> + /* [a b c f g] = 0, [e, ...] = 1
> + [f g] = 0 should mask e, leave [c d] intact. */
> + if (/* conditions(5/24) true(0 1 2 3 4 5 6 7 8 9 10 11) false(3 4 7 8 9 10 11) */
> + /* conditions(end) */
> + (a || b)
> + || ( ((c && d) || (e && (f || g) && h))
> + && (k || l)
> + && (m || n)))
> + x = a + b;
> + else
> + x = b + c;
> +}
> +
> +void
> +mcdc023g (int a, int b, int c, int d, int e, int f, int g, int h, int i, int k,
> + int l, int m, int n)
> +{
> + /* [a b d f g] = 0, [e c, ...] = 1
> + Same as 023f but with [c d] flipped so d masks c rather than c
> + short-circuits. This should not be lost. */
> + if (/* conditions(5/24) true(0 1 2 3 4 5 6 7 8 9 10 11) false(2 4 7 8 9 10 11) */
> + /* conditions(end) */
> + (a || b)
> + || ( ((c && d) || (e && (f || g) && h))
> + && (k || l)
> + && (m || n)))
> + x = a + b;
> + else
> + x = b + c;
> +}
> +
> +/* Gotos, return, labels can make odd graphs. It is important that conditions
> + are assigned to the right expression, and that there are no miscounts. In
> + these tests values may be re-used, as checking things like masking an
> + independence is done in other test cases and not so useful here. */
> +void
> +mcdc024a (int a, int b)
> +{
> + /* This is a reference implementation without the labels, which should not
> + alter behavior. */
> + if (a && b) /* conditions(2/4) true(0 1) */
> + /* conditions(end) */
> + {
> + x = 1;
> + }
> + else
> + {
> + x = 2;
> + }
> +
> + if (a || b) /* conditions(2/4) false(0 1) */
> + /* conditions(end) */
> + {
> + x = 1;
> + }
> + else
> + {
> + x = 2;
> + }
> +}
> +
> +void
> +mcdc024b (int a, int b)
> +{
> + if (a && b) /* conditions(2/4) true(0 1) */
> + /* conditions(end) */
> + {
> +label1:
> + x = 1;
> + }
> + else
> + {
> + x = 2;
> + }
> +
> + if (a || b) /* conditions(2/4) false(0 1) */
> + /* conditions(end) */
> + {
> +label2:
> + x = 1;
> + }
> + else
> + {
> + x = 2;
> + }
> +}
> +
> +void
> +mcdc024c (int a, int b)
> +{
> +
> + if (a && b) /* conditions(2/4) true(0 1) */
> + /* conditions(end) */
> + {
> + x = 1;
> + }
> + else
> + {
> +label1:
> + x = 2;
> + }
> +
> + if (a || b) /* conditions(2/4) false(0 1) */
> + /* conditions(end) */
> + {
> + x = 1;
> + }
> + else
> + {
> +label2:
> + x = 2;
> + }
> +}
> +
> +void
> +mcdc024d (int a, int b)
> +{
> + if (a && b) /* conditions(2/4) true(0 1) */
> + /* conditions(end) */
> + {
> +label1:
> + x = 1;
> + }
> + else
> + {
> +label2:
> + x = 2;
> + }
> +
> + if (a || b) /* conditions(2/4) false(0 1) */
> + /* conditions(end) */
> + {
> +label3:
> + x = 1;
> + }
> + else
> + {
> +label4:
> + x = 2;
> + }
> +}
> +
> +int
> +mcdc024e (int a, int b, int c)
> +{
> + /* Graphs can get complicated with the innermost returns and else-less if,
> + so we must make sure these conditions are counted correctly. */
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + {
> + if (b) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + if (c) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return 1;
> + else
> + return 2;
> + }
> +
> + if (a) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return 3;
> + }
> +
> + return 5;
> +}
> +
> +/* Nested else-less ifs with inner returns needs to be counted right, which
> + puts some pressure on the expression isolation. */
> +int
> +mcdc024f (int a, int b, int c)
> +{
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + {
> + if (b) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + if (c) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + if (a) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return 1;
> + else
> + return 2;
> + }
> +
> + if (a) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return 3;
> + }
> +
> + if (b) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return 4;
> + }
> + return 5;
> +}
> +
> +int
> +mcdc024g (int a, int b, int c)
> +{
> + if (b) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + return 0;
> +
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + {
> + if (b) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + b += 2;
> + if (b & 0xFF) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + c++;
> +
> + return c;
> + }
> + c += 10;
> + }
> + return 1;
> +}
> +
> +
> +int
> +mcdc024h (int a, int b, int c)
> +{
> + if (b) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + goto inner;
> +
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + ++a;
> +
> +
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + {
> + if (b) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> +inner:
> + b += 2;
> + if (b & 0xFF) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + c++;
> +
> + return c;
> + }
> + c += 10;
> + }
> + return 1;
> +}
> +
> +int
> +mcdc024i (int a, int b, int c)
> +{
> +fst:
> + b++;
> +snd:
> + b++;
> +
> + if (b > 10) /* conditions(2/2) */
> + /* conditions(end) */
> + goto end;
> +
> + if (b < 5) /* conditions(2/2) */
> + /* conditions(end) */
> + goto fst;
> + else
> + goto snd;
> +
> +end:
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + ++a;
> +
> +
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + {
> + if (b) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + b += 2;
> + if (b & 0xFF) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + c++;
> +
> + return c;
> + }
> + c += 10;
> + }
> + return 1;
> +}
> +
> +/* Adapted from alsa-lib 1.2.8 src/control/control.c. If two expressions share
> + an outcome with bypass nodes they would be handled twice. */
> +int
> +mcdc025a (int a, int b, int c)
> +{
> + int err;
> + if (id (a)) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + {
> + if (b) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return -1;
> + }
> + else
> + {
> + err = id (c);
> + if (err > 0) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + return err;
> + }
> + err = id (a);
> + return err;
> +}
> +
> +/* Boolean expressions in function call parameters. These tests are all built
> + with a reference expression which should behave the same as the function
> + call versions. */
> +int
> +mcdc026a (int a, int b, int c, int d, int e)
> +{
> + int cad = c && d; /* conditions(4/4) */
> + /* conditions(end) */
> + int x = a && b && cad && e; /* conditions(5/8) false(0 1 3) */
> + /* conditions(end) */
> + int y = a && b && id (c && d) && e; /* conditions(5/8; 4/4) false(0 1 3;;) */
> + /* conditions(end) */
> + return x + y;
> +}
> +
> +int
> +mcdc026b (int a, int b, int c, int d, int e)
> +{
> + int dae = d && e; /* conditions(3/4) false(1) */
> + /* conditions(end) */
> + int x = a && b && c && dae; /* conditions(6/8) false(0 1) */
> + int y = a && b && c && id (d && e); /* conditions(6/8; 3/4) false(0 1; 1) */
> + /* conditions(end) */
> + return x + y;
> +}
> +
> +int
> +mcdc026c (int a, int b, int c, int d, int e)
> +{
> + int cod = c || d; /* conditions(3/4) true(1) */
> + /* conditions(end) */
> + int x = a && b && cod && e; /* conditions(5/8) false(0 1 3) */
> + int y = a && b && id (c || d) && e; /* conditions(5/8; 3/4) true(;1) false(0 1 3;) */
> + /* conditions(end) */
> + return x+y;
> +}
> +
> +int
> +mcdc026d (int a, int b, int c, int d, int e)
> +{
> + int aab = a && b; /* conditions(2/4) false(0 1) */
> + /* conditions(end) */
> + int cod = c || d; /* conditions(3/4) true(1) */
> + /* conditions(end) */
> + int x = aab && cod && e; /* conditions(4/6) false(0 2) */
> + /* conditions(end) */
> + int y = id (a && b) && id (c || d) && e; /* conditions(2/4;4/6;3/4) true(;;1) false(0 1;0 2;;) */
> + /* conditions(end) */
> + return x + y;
> +}
> +
> +int
> +mcdc026e (int a, int b, int c, int d, int e)
> +{
> + int cod = c || d; /* conditions(3/4) true(1) */
> + /* conditions(end) */
> + int dae = d && e; /* conditions(3/4) false(1) */
> + /* conditions(end) */
> + int aacod = a && cod; /* conditions(3/4) false(0)*/
> + /* conditions(end) */
> + int x = aacod && dae; /* conditions(4/4) */
> + /* conditions(end) */
> + int y = id (a && id (c || d)) && id (d && e); /* conditions(3/4; 3/4; 4/4; 3/4) true(;1;;) false(0;;;1) */
> + /* conditions(end) */
> + return x + y;
> +}
> +
> +int main ()
> +{
> + mcdc001a (0, 1);
> +
> + mcdc001b (0, 1);
> + mcdc001b (0, 0);
> +
> + mcdc001c (0, 1);
> + mcdc001c (0, 0);
> + mcdc001c (1, 1);
> +
> + mcdc001d (1, 1, 1);
> + mcdc001d (0, 1, 0);
> +
> + mcdc002a (1, 0);
> +
> + mcdc002b (1, 0);
> + mcdc002b (1, 1);
> +
> + mcdc002c (0, 0);
> + mcdc002c (1, 1);
> + mcdc002c (1, 0);
> +
> + mcdc002d (1, 1, 1);
> + mcdc002d (1, 0, 0);
> +
> + mcdc003a (0, 0);
> + mcdc003a (1, 0);
> +
> + mcdc004a (0);
> + mcdc004b (0);
> + mcdc004b (1);
> + mcdc004c (1);
> +
> + mcdc004d (0, 0, 0);
> + mcdc004d (1, 1, 1);
> +
> + mcdc004e (0, 0, 0);
> + mcdc004e (1, 1, 1);
> +
> + mcdc004f (1, 1, 1);
> +
> + mcdc005a (1, 0, 1);
> +
> + mcdc005b (1, 1, 0, 0);
> + mcdc005b (1, 0, 0, 0);
> +
> + mcdc005c (0, 1, 1, 0);
> +
> + mcdc005d (1, 0, 0, 0);
> +
> + mcdc005e (0, 0);
> + mcdc005e (0, 1);
> + mcdc005e (1, 0);
> + mcdc005e (1, 1);
> +
> + mcdc006a (0, 0, 0, 0, 0);
> + mcdc006a (1, 0, 0, 0, 0);
> + mcdc006a (1, 1, 1, 0, 0);
> +
> + mcdc006b (0, 0, 0);
> + mcdc006b (1, 0, 0);
> + mcdc006b (1, 1, 0);
> + mcdc006b (1, 1, 1);
> +
> + mcdc006c (0, 0, 0);
> + mcdc006c (1, 0, 0);
> + mcdc006c (1, 1, 0);
> + mcdc006c (1, 1, 1);
> +
> + mcdc006d (1, 0, 0);
> + mcdc006d (1, 0, 1);
> +
> + mcdc006e (0, 0, 0, 0);
> + mcdc006e (0, 0, 1, 0);
> + mcdc006e (0, 1, 0, 0);
> +
> + mcdc007a (0, 0, 0, 0);
> + mcdc007a (1, 0, 0, 0);
> + mcdc007a (0, 0, 1, 0);
> +
> + mcdc007b (0, 0, 0);
> + mcdc007b (0, 1, 1);
> + mcdc007b (1, 0, 1);
> +
> + mcdc007c (0, 0, 0);
> + mcdc007c (0, 1, 1);
> + mcdc007c (1, 0, 1);
> +
> + mcdc007d (0, 1, 0, 1, 1);
> +
> + mcdc008a (0);
> +
> + mcdc008b (0);
> +
> + mcdc008c (0);
> + mcdc008c (1);
> +
> + mcdc008d (0, 0, 0, 0);
> + mcdc008d (1, 0, 0, 0);
> + mcdc008d (1, 0, 1, 0);
> + mcdc008d (1, 0, 1, 1);
> + mcdc008d (1, 1, 1, 1);
> +
> + mcdc009a (0, 0);
> + mcdc009a (1, 1);
> +
> + mcdc009b (0, 0);
> + mcdc009b (1, 0);
> +
> + mcdc010a (0, 0);
> + mcdc010a (0, 9);
> + mcdc010a (2, 1);
> +
> + mcdc010b ();
> +
> + mcdc010c (0, 0, 0);
> + mcdc010c (0, 1, 0);
> +
> + mcdc010d (1);
> +
> + mcdc011a (0, 0, 0);
> + mcdc011a (1, 1, 0);
> + mcdc011a (1, 0, 1);
> +
> + mcdc012a (0, 0, 0);
> + mcdc012a (0, 1, 1);
> +
> + mcdc013a (0, 0, 0);
> + mcdc013a (0, 0, 1);
> + mcdc013a (0, 1, 0);
> + mcdc013a (0, 1, 1);
> + mcdc013a (1, 0, 0);
> + mcdc013a (1, 0, 1);
> + mcdc013a (1, 1, 0);
> + mcdc013a (1, 1, 1);
> +
> + mcdc014a ();
> +
> + mcdc015a (0, 0);
> + mcdc015a (1, 0);
> +
> + mcdc015b (0, 0);
> + mcdc015b (0, 1);
> + mcdc015b (6, 1);
> +
> + mcdc015c (0, 0);
> + mcdc015c (0, 5);
> + mcdc015c (6, 1);
> +
> + mcdc015d (1, 0, 0);
> +
> + mcdc016a (5, 5);
> +
> + mcdc016b (5, 5);
> + mcdc016b (6, 5);
> +
> + mcdc016c (5, 5);
> +
> + mcdc016d (1, 0);
> +
> + mcdc017a (0);
> + mcdc017a (2);
> +
> + mcdc017b (2, 0);
> + mcdc017b (0, 1);
> +
> + mcdc017c (1, 1);
> +
> + mcdc018a (0, 0, 1, 1, 0, 0, 0, 0);
> + mcdc018a (0, 1, 0, 0, 0, 0, 1, -2);
> + mcdc018a (0, 6, 0, 0, 0, 0, 1, -2);
> + mcdc018a (0, 6, 0, 0, 0, 0, 1, -2);
> + mcdc018a (0, 0, 0, 1, 0, 1, 1, 0);
> + mcdc018a (1, 0, 0, 0, 1, 1, 0, 0);
> +
> + mcdc018b (1, 0, 0);
> + mcdc018b (1, 1, 0);
> +
> + mcdc018c (1, 1);
> +
> + mcdc019a ();
> +
> + mcdc020a (0);
> + mcdc020a (1);
> +
> + mcdc020b (0, 0);
> + mcdc020b (1, 0);
> +
> + mcdc020c (0, 1);
> + mcdc020c (1, 1);
> +
> + mcdc020d (0, 0, 0, 0, 0);
> + mcdc020d (1, 0, 0, 1, 1);
> + mcdc020d (1, 1, 0, 1, 1);
> +
> + mcdc021d (1, 0, 1, 0);
> +
> + mcdc022a (0, 0);
> +
> + mcdc022b (0);
> + mcdc022b (1);
> +
> + mcdc022c (0);
> + mcdc022c (1);
> +
> + mcdc022d (1);
> + mcdc022e (0, 1, 1, 0);
> +
> + mcdc023a (0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1);
> + mcdc023b (0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1);
> + mcdc023c (0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0);
> + mcdc023d (0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1);
> + mcdc023e (0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1);
> + mcdc023f (0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1);
> + mcdc023g (0, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1);
> +
> + mcdc024a (0, 1);
> + mcdc024b (0, 1);
> + mcdc024c (0, 1);
> + mcdc024d (0, 1);
> + mcdc024a (1, 0);
> + mcdc024b (1, 0);
> + mcdc024c (1, 0);
> + mcdc024d (1, 0);
> +
> + mcdc024e (0, 0, 0);
> + mcdc024f (0, 0, 0);
> + mcdc024g (0, 0, 0);
> + mcdc024h (0, 0, 0);
> + mcdc024i (0, 0, 0);
> +
> + mcdc025a (0, 0, 1);
> +
> + mcdc026a (1, 1, 1, 0, 1);
> + mcdc026a (1, 1, 0, 0, 1);
> + mcdc026a (1, 1, 1, 1, 1);
> +
> + mcdc026b (1, 1, 1, 0, 1);
> + mcdc026b (1, 1, 0, 0, 1);
> + mcdc026b (1, 1, 1, 1, 1);
> +
> + mcdc026c (1, 1, 1, 0, 1);
> + mcdc026c (1, 1, 0, 0, 1);
> + mcdc026c (1, 1, 1, 1, 1);
> +
> + mcdc026d (1, 1, 1, 0, 1);
> + mcdc026d (1, 1, 0, 0, 1);
> + mcdc026d (1, 1, 1, 1, 1);
> +
> + mcdc026e (1, 1, 1, 0, 1);
> + mcdc026e (1, 1, 0, 0, 1);
> + mcdc026e (1, 1, 1, 1, 1);
> +}
> +
> +/* { dg-final { run-gcov conditions { --conditions gcov-19.c } } } */
> diff --git a/gcc/testsuite/gcc.misc-tests/gcov-20.c b/gcc/testsuite/gcc.misc-tests/gcov-20.c
> new file mode 100644
> index 00000000000..215faffc980
> --- /dev/null
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-20.c
> @@ -0,0 +1,22 @@
> +/* { dg-options "-fcondition-coverage -ftest-coverage -fprofile-update=atomic" } */
> +/* { dg-do run { target native } } */
> +
> +/* Some side effect to stop branches from being pruned */
> +int x = 0;
> +
> +void
> +conditions_atomic001 (int a, int b)
> +{
> + if (a || b) /* conditions(1/4) true(0) false(0 1) */
> + /* conditions(end) */
> + x = 1;
> + else
> + x = 2;
> +}
> +
> +int main ()
> +{
> + conditions_atomic001 (0, 1);
> +}
> +
> +/* { dg-final { run-gcov conditions { --conditions gcov-20.c } } } */
> diff --git a/gcc/testsuite/gcc.misc-tests/gcov-21.c b/gcc/testsuite/gcc.misc-tests/gcov-21.c
> new file mode 100644
> index 00000000000..3395422166a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-21.c
> @@ -0,0 +1,16 @@
> +/* { dg-options "-fcondition-coverage" } */
> +
> +/* https://gcc.gnu.org/pipermail/gcc-patches/2022-April/592927.html */
> +char trim_filename_name;
> +int r;
> +
> +void trim_filename() {
> + if (trim_filename_name)
> + r = 123;
> + while (trim_filename_name)
> + ;
> +}
> +
> +int main ()
> +{
> +}
> diff --git a/gcc/testsuite/gcc.misc-tests/gcov-22.c b/gcc/testsuite/gcc.misc-tests/gcov-22.c
> new file mode 100644
> index 00000000000..641791a7223
> --- /dev/null
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-22.c
> @@ -0,0 +1,103 @@
> +/* { dg-options "-fcondition-coverage -ftest-coverage" } */
> +/* { dg-do run { target native } } */
> +
> +#include <setjmp.h>
> +jmp_buf buf;
> +
> +void noop () {}
> +int identity (int x) { return x; }
> +
> +/* This function is a test to verify that the expression isolation does not
> + break on a CFG with the right set of complex edges. The (_ && setjmp)
> + created complex edges after the function calls and a circular pair of
> + complex edges around the setjmp call. This triggered a bug when the search
> + for right operands only would consider nodes dominated by the left-most
> + term, as this would only be the case if the complex edges were removed. (_
> + && setjmp) is undefined behavior, but it does happen in the wild.
> +
> + __builtin_setjmp did not trigger this, so we need setjmp from libc. */
> +void
> +setjmp001 (int a, int b, int c)
> +{
> + if (a) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + noop ();
> +
> + if (b) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + noop ();
> +
> + if (c && setjmp (buf)) /* conditions(1/4) true(0 1) false(1) */
> + /* conditions(end) */
> + noop ();
> +}
> +
> +/* Adapted from freetype-2.13.0 gxvalid/gxvmod.c classic_kern_validate */
> +int
> +setjmp002 (int a)
> +{
> + int error = identity(a);
> +
> + if (error) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + goto Exit;
> +
> + if (a+1) /* conditions(1/2) false(0) */
> + /* conditions(end) */
> + {
> + noop ();
> + if (setjmp (buf)) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + noop ();
> +
> + if (error) /* conditions(1/2) true(0) */
> + /* conditions(end) */
> + noop ();
> + }
> +
> + error--;
> +
> +Exit:
> + return error;
> +}
> +
> +int
> +setjmp003 (int a)
> +{
> + /* || setjmp is undefined behavior, so the result here does not have to
> + make sense. It would be nice if the result is not something like 35/4
> + conditions covered. */
> + if (a || setjmp (buf)) /* conditions(suppress) */
> + /* conditions(end) */
> + a += 12;
> +
> + return a;
> +}
> +
> +jmp_buf dest;
> +
> +int
> +setdest ()
> +{
> + if (setjmp (dest)) /* conditions(2/2) */
> + return 1;
> + return 2;
> +}
> +
> +void
> +jump ()
> +{
> + longjmp (dest, 1);
> +}
> +
> +int
> +main ()
> +{
> + setjmp001 (0, 1, 0);
> + setjmp002 (0);
> + setjmp003 (0);
> + setdest ();
> + jump ();
> +}
> +
> +/* { dg-final { run-gcov conditions { --conditions gcov-22.c } } } */
> diff --git a/gcc/testsuite/gcc.misc-tests/gcov-23.c b/gcc/testsuite/gcc.misc-tests/gcov-23.c
> new file mode 100644
> index 00000000000..72849d80e3a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-23.c
> @@ -0,0 +1,361 @@
> +/* { dg-options "-fcondition-coverage -ftest-coverage -O2 -c" } */
> +
> +#include <stdint.h>
> +#include <limits.h>
> +#include <setjmp.h>
> +jmp_buf buf;
> +
> +int id (int);
> +int idp (int *);
> +int err;
> +char c;
> +
> +/* This becomes problematic only under optimization for the case when the
> + compiler cannot inline the function but have to generate a call. It is not
> + really interesting to run, only build. Notably, both the function calls and
> + the return values are important to construct a problematic graph.
> +
> + This test is also a good example of where optimization makes condition
> + coverage unpredictable, but not unusable. If this is built without
> + optimization the conditions work as you would expect from reading the
> + source. */
> +/* Adapted from cpio-2.14 gnu/utmens.c lutimens (). */
> +int
> +mcdc001 (int *v)
> +{
> + int adjusted;
> + int adjustment_needed = 0;
> +
> + int *ts = v ? &adjusted : 0; /* conditions(0/4) true(0 1) false(0 1) */
> + /* conditions(end) */
> + if (ts)
> + adjustment_needed = idp (ts);
> + if (adjustment_needed < 0)
> + return -1;
> +
> + if (adjustment_needed) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + if (adjustment_needed != 3) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return -1;
> + if (ts) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return 0;
> + }
> +
> + if (adjustment_needed && idp (&adjusted)) /* conditions(0/4) true(0 1) false(0 1) */
> + /* conditions(end) */
> + return -1;
> + if (adjusted) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return idp (ts);
> +
> + return -1;
> +}
> +
> +/* This failed when the candidate set internal/contracted-past nodes were not
> + properly marked as reachable in the candidate reduction phase. */
> +/* Adapted from cpio-2.14 gnu/mktime.c mktime_internal (). */
> +int
> +mcdc002 ()
> +{
> + int a;
> + if (idp (&a)) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + if (id (a)) /* conditions(0/2) true(0/2) true(0) false(0) */
> + /* conditions(end) */
> + goto exit;
> +
> + if (err) /* conditions(0/2) true(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return -1;
> + }
> +
> +exit:
> + return a;
> +}
> +
> +/* Adapted from icu4c-73.1 common/ucase.cpp ucase_getCaseLocale (). */
> +int
> +mcdc003 (const char *locale)
> +{
> + /* extern, so its effect won't be optimized out. */
> + c = *locale++;
> + if (c == 'z') /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + return 1;
> + }
> + else if (c >= 'a') /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + {
> + if (id (c)) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + c = *locale++;
> + }
> + else
> + {
> + if (c == 'T')
> + {
> + if (id (c)) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + c = *locale++;
> + if (id (c)) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + c = *locale++;
> + }
> + /* This may or may not become a jump table. */
> + else if (c == 'L') /* conditions(suppress) */
> + /* conditions(end) */
> + c = *locale++;
> + else if (c == 'E') /* conditions(suppress) */
> + /* conditions(end) */
> + c = *locale++;
> + else if (c == 'N') /* conditions(suppress) */
> + /* conditions(end) */
> + c = *locale++;
> + else if (c == 'H') /* conditions(suppress) */
> + /* conditions(end) */
> + {
> + c = *locale++;
> + if (id (c)) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + c = *locale++;
> + }
> + }
> +
> + return 1;
> +}
> +
> +/* The || will be changed to |, so it is impractical to predict the number of
> + conditions. If the walk is not properly implemented this will not finish
> + compiling, so the actual coverage is not interesting. */
> +/* Adapted from icu4c-73.1 common/uresdata.cpp res_findResource (). */
> +int
> +mcdc004 (int r, char* path, char* key)
> +{
> + char *idcc (char *, char);
> + #define is_kind1(type) ((type) == 23 || (type) == 14 || (type == 115))
> + #define is_kind2(type) ((type) == 16 || (type) == 77 || (type == 118))
> + #define is_kind12(type) (is_kind1 ((type)) || is_kind2 ((type)))
> +
> + char *nextSepP = path;
> + int t1 = r;
> + int type = id (t1);
> +
> + if (!is_kind12 (type)) /* conditions(suppress) */
> + /* conditions(end) */
> + return -1;
> +
> + while (*path && t1 != -1 && is_kind12 (type)) /* conditions(suppress) */
> + /* conditions(end) */
> + {
> + nextSepP = idcc(path, '/');
> + if(nextSepP == path) /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + return -1;
> +
> + if (*nextSepP == 'a') /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + *key = *path;
> + else if (*nextSepP == 'b') /* conditions(0/2) true(0) false(0) */
> + /* conditions(end) */
> + *key = 0;
> + type = t1;
> + }
> +
> + return t1;
> +}
> +
> +/* Adapted from jxl 0.8.2 lib/extras/dec/apng.cc processing_start ().
> + This created a graph where depth-first traversal of the CFG would not
> + process nodes in the wrong order (the extra control inserted from setjmp
> + created a path of complexes from root to !b without going through !a).
> +
> + This only happened under optimization. */
> +int
> +mcdc005 (int a, int b)
> +{
> + a = id (a);
> + b = id (b);
> +
> + /* The a || b gets transformed to a | b, then fused with setjmp because
> + they both have the same return value. */
> + if (a || b) /* conditions(0/4) true(0 1) false(0 1) */
> + /* conditions(end) */
> + return 1;
> + else
> + a += 1;
> +
> + if (setjmp (buf))
> + return 1;
> +
> + return a;
> +}
> +
> +/* Adapted from cpio-2.14 gnu/quotearg.c quotearg_buffer_restyled. The ifs in
> + the cases (with fallthrough) re-use the same value which under optimization
> + causes path reuse which must be sorted out. */
> +int
> +mcdc006 (int quoting_style, int elide, int *buffer)
> +{
> + int backslash = 0;
> + switch (quoting_style)
> + {
> + case 1:
> + if (!elide)
> + backslash = 1;
> + case 2:
> + if (!elide)
> + if (buffer)
> + *buffer = '"';
> + }
> +
> + if (quoting_style == 2 && backslash)
> + quoting_style = 1;
> + return 1;
> +}
> +
> +/* Adapted from pcre2-10.42 pcre2_compile.c pcre2_compile. If SSA nodes are
> + created at the wrong place in the block it will fail flow analysis (because
> + the label is in the middle of block), caused by the final break in this
> + case. */
> +void
> +mcdc007 (int options, int *pso, int len)
> +{
> + if (options == 5)
> + return;
> +
> + while (options--)
> + {
> + int i;
> + for (i = 0; i < len; i++)
> + {
> + int *p = pso + i;
> + int skipatstart = *p + 2;
> + if (skipatstart) {
> + switch(*p)
> + {
> + case 1:
> + *p |= *p + 1;
> + break;
> + case 2:
> + skipatstart += *p - skipatstart;
> + break;
> + }
> + break;
> + }
> + }
> + if (i >= len) break;
> + }
> +}
> +
> +/* Adapted from alsa-lib 1.2.8 pcm/pcm.c snd_pcm_chmap_print. */
> +int
> +mcdc008 (int *map, unsigned maxlen, int *buf)
> +{
> + unsigned int len = 0;
> + for (unsigned i = 0; i < *map; i++) {
> + unsigned int p = map[i] & 0xF;
> + if (i > 0) {
> + if (len >= maxlen)
> + return -1;
> + }
> + if (map[i] & 0xFF)
> + len += idp (buf + len);
> + else {
> + len += idp (buf);
> + }
> + if (map[i] & 0xFF00) {
> + len += idp (buf + len);
> + if (len >= maxlen)
> + return -1;
> + }
> + }
> + return len;
> +}
> +
> +/* Adapted from cpio-2.14 gnu/mktime.c mktime_internal (). The combination of
> + goto, automatic variables, and the ternary causes the post dominator of the
> + highest topological ordered node not to be the common post dominator of the
> + expression as a whole. */
> +int
> +mcdc009 (int *tp, int t, int isdst)
> +{
> + int t0 = tp[0];
> + int t1 = tp[1];
> + int t2 = tp[2];
> +
> + if (t0 < 0 || (isdst < 0 ? t1 : (isdst != 0)))
> + goto offset_found;
> +
> + if (t == 0)
> + return -1;
> +
> + t1 = t2;
> +
> +offset_found:
> + return t;
> +}
> +
> +/* Adapted from Berkeley db 4.8.30 rep/rep_elect.c __rep_cmp_vote. This
> + particular combination of fallthrough and folding creates a path into the
> + the inner if () that does not go through the first basic condition. */
> +void
> +mcdc010 (int cmp, int *rep, int sites, int priority, int flags)
> +{
> + if (sites > 1 && (priority != 0 || (flags & 0xFF)))
> + {
> + if ( (priority != 0 && *rep == 0)
> + || (((priority == 0 && *rep == 0)
> + || (priority != 0 && *rep != 0)) && cmp > 0))
> + {
> + *rep = cmp;
> + }
> + }
> +}
> +
> +/* For not sufficiently protected back edges this would create an infinite
> + loop. */
> +void
> +mcdc011 (int a, int b)
> +{
> + if (a && id (b))
> + for (;;) {}
> + id (a+1);
> +}
> +
> +/* Adapted from alsa-1.2.8 tlv.c get_tlv_info (). Under optimization, the
> + conditions may be replaced with min (). */
> +int
> +mcdc012 (int x, int y)
> +{
> + int err;
> + err = id (x);
> + if (err < 0)
> + return err;
> + err = id (y);
> + if (err < 0)
> + return err;
> + return 0;
> +}
> +
> +/* Adapted from alsa-1.2.8 control.c snd_ctl_elem_id_compare_numid (). This
> + test is probably not so accurate on targets where int == int64. Under
> + optimization, the conditions may be replaced with min/max. */
> +int
> +mcdc013 (const int64_t *id1, const int64_t *id2)
> +{
> + int64_t d;
> + d = *id1 - *id2;
> + if (d & 0xFF)
> + {
> + if (d > INT_MAX)
> + d = INT_MAX;
> + else if (d < INT_MIN)
> + d = INT_MIN;
> + }
> + return d;
> +}
> diff --git a/gcc/testsuite/lib/gcov.exp b/gcc/testsuite/lib/gcov.exp
> index e5e94fa5a76..5a3e20ce374 100644
> --- a/gcc/testsuite/lib/gcov.exp
> +++ b/gcc/testsuite/lib/gcov.exp
> @@ -174,6 +174,252 @@ proc verify-branches { testname testcase file } {
> return $failed
> }
>
> +#
> +# verify-conditions -- check that conditions are checked as expected
> +#
> +# TESTNAME is the name of the test, including unique flags.
> +# TESTCASE is the name of the test file.
> +# FILE is the name of the gcov output file.
> +#
> +# Checks are based on comments in the source file. Condition coverage comes
> +# with with two types of output, a summary and a list of the uncovered
> +# conditions. Both must be checked to pass the test
> +#
> +# To check for conditions, add a comment the line of a conditional:
> +# /* conditions(n/m) true(0 1) false(1) */
> +#
> +# where n/m are the covered and total conditions in the expression. The true()
> +# and false() take the indices expected *not* covered.
> +#
> +# This means that all coverage statements should have been seen:
> +# /* conditions(end) */
> +#
> +# If all conditions are covered i.e. n == m, then conditions(end) can be
> +# omitted. If either true() or false() are empty they can be omitted too.
> +#
> +# In some very specific cases there is a need to match multiple conditions on
> +# the same line, for example if (a && fn (b || c) && d), which is interpreted
> +# roughly as tmp _bc = b || c; if (a && _bc && d). The argument to fn is
> +# considered its own expression and its coverage report will be written on the
> +# same line. For these cases, use conditions(n/m; n/m;...) true(0 1;;...)
> +# where ; marks the end of the list element where the ith list matches the ith
> +# expression. The true()/false() matchers can be omitted if no expression
> +# expects them, otherwise use the empty list if all true/false outcomes are
> +# covered.
> +#
> +# C++ can insert conditionals in the CFG that are not present in source code.
> +# These must be manually suppressed since unexpected and unhandled conditions
> +# are an error (to help combat regressions). Output can be suppressed with
> +# conditions(suppress) and conditions(end). suppress should usually be on a
> +# closing brace.
> +#
> +# Some expressions, when using unnamed temporaries as operands, will have
> +# destructors in expressions. The coverage of the destructor will be reported
> +# on the same line as the expression itself, but suppress() would also swallow
> +# the expected tested-for messages. To handle these, use the destructor() [1]
> +# which will suppress everything from and including the second "conditions
> +# covered".
> +#
> +# [1] it is important that the destructor() is *on the same line* as the
> +# conditions(m/n)
> +proc verify-conditions { testname testcase file } {
> + set failed 0
> + set suppress 0
> + set destructor 0
> + set should ""
> + set shouldt ""
> + set shouldf ""
> + set shouldall ""
> + set fd [open $file r]
> + set lineno 0
> + set checks [list]
> + set keywords {"end" "suppress"}
> + while {[gets $fd line] >= 0} {
> + regexp "^\[^:\]+: *(\[0-9\]+):" "$line" all lineno
> + set prefix "$testname line $lineno"
> +
> + if {![regexp "condition" $line]} {
> + continue
> + }
> +
> + # Missing coverage for both true and false will cause a failure, but
> + # only count it once for the report.
> + set ok 1
> + if [regexp {conditions *\([0-9a-z/; ]+\)} "$line" all] {
> + # *Very* coarse sanity check: conditions() should either be a
> + # keyword or n/m, anything else means a buggy test case. end is
> + # optional for cases where all conditions are covered, since it
> + # only expects a single line of output.
> + regexp {conditions *\(([0-9a-z/]+)\)} "$line" all e
> + if {([lsearch -exact $keywords $e] >= 0 || [regexp {\d+/\d+} "$e"]) == 0} {
> + fail "$prefix: expected conditions (n/m), (suppress) or (end); was ($e)"
> + incr failed
> + continue
> + }
> +
> + # Any keyword means a new context. Set the error flag if not all
> + # expected output has been seen, and reset the state.
> + if {[llength $shouldt] != 0} {
> + fail "$prefix: expected 'not covered (true)' for terms: $shouldt"
> + set ok 0
> + }
> +
> + if {[llength $shouldf] != 0} {
> + fail "$prefix: expected 'not covered (false)' for terms: $shouldf"
> + set ok 0
> + }
> +
> + if {$shouldall ne ""} {
> + fail "$prefix: coverage summary not found; expected $shouldall"
> + set ok 0
> + }
> +
> + if {[llength $checks] != 0} {
> + set missing [llength checks]
> + fail "$prefix: expected $missing more conditions"
> + set ok 0
> + }
> +
> + set suppress 0
> + set destructor 0
> + set setup 0
> + set checks [list]
> +
> + if [regexp {destructor\(\)} "$line"] {
> + set destructor 1
> + }
> +
> + # Find the expressions on this line. There may be more, to support
> + # constructs like (a && fn (b && c) && d).
> + # The match produces lists like [conditions(n/m) n m]
> + set argconds ""
> + set argtrue ""
> + set argfalse ""
> + regexp {conditions *\(([0-9 /;]+)\)} $line _ argconds
> + regexp {true *\(([0-9 ;]+)\)} $line _ argtrue
> + regexp {false *\(([0-9 ;]+)\)} $line _ argfalse
> + set condv [split $argconds ";"]
> + set truev [split $argtrue ";"]
> + set falsev [split $argfalse ";"]
> + set ncases [llength $condv]
> +
> + for {set i 0} {$i < $ncases} {incr i} {
> + set summary [lindex $condv $i]
> + set n [lindex [split $summary "/"] 0]
> + set m [lindex [split $summary "/"] 1]
> + set newt [lindex $truev $i]
> + set newf [lindex $falsev $i]
> +
> + # Sanity check - if the true() and false() vectors should have
> + # m-n elements to cover all uncovered conditions. Because of
> + # masking it can sometimes be surprising what terms are
> + # independent, so this makes for more robust test at the cost
> + # of being slightly more annoying to write.
> + set nterms [expr [llength $newt] + [llength $newf]]
> + set nexpected [expr {$m - $n}]
> + if {$nterms != $nexpected} {
> + fail "$prefix: expected $nexpected uncovered terms; got $nterms"
> + set ok 0
> + }
> + set shouldall $e
> + set should ""
> + set shouldt $newt
> + set shouldf $newf
> + set shouldall [regsub -all { } "$n/$m" ""]
> + lappend checks [list $should $shouldt $shouldf $shouldall $newt $newf]
> + }
> +
> + if {[llength $checks] > 0} {
> + # no-op - the stack of checks to do is set up
> + } elseif {$e == "end"} {
> + # no-op - state should already been reset, and errors flagged
> + } elseif {$e == "suppress"} {
> + set suppress 1
> + } else {
> + # this should be unreachable,
> + fail "$prefix: unhandled control ($e), should be unreachable"
> + set ok 0
> + }
> + } elseif {$suppress == 1} {
> + # ignore everything in a suppress block. C++ especially can insert
> + # conditionals in exceptions and destructors which would otherwise
> + # be considered unhandled.
> + continue
> + } elseif [regexp {condition +(\d+) not covered \((.*)\)} "$line" all cond condv] {
> + foreach v {true false} {
> + if [regexp $v $condv] {
> + if {"$v" == "true"} {
> + set should shouldt
> + } else {
> + set should shouldf
> + }
> +
> + set i [lsearch [set $should] $cond]
> + if {$i != -1} {
> + set $should [lreplace [set $should] $i $i]
> + } else {
> + fail "$prefix: unexpected uncovered term $cond ($v)"
> + set ok 0
> + }
> + }
> + }
> + } elseif [regexp {condition outcomes covered (\d+/\d+)} "$line" all cond] {
> + # the destructor-generated "conditions covered" lines will be
> + # written after all expression-related output. Handle these by
> + # turning on suppression if the destructor-suppression is
> + # requested.
> + if {$shouldall == "" && $destructor == 1} {
> + set suppress 1
> + continue
> + }
> +
> + if {[llength $checks] == 0} {
> + fail "$prefix: unexpected summary $cond"
> + set ok 0
> + } else {
> + # Report any missing conditions from the previous set if this
> + # is not the first condition block
> + if {$setup == 1} {
> + if {[llength $shouldt] != 0} {
> + fail "$prefix: expected 'not covered (true)' for terms: $shouldt"
> + set ok 0
> + }
> + if {[llength $shouldf] != 0} {
> + fail "$prefix: expected 'not covered (false)' for terms: $shouldf"
> + set ok 0
> + }
> + if {$shouldall ne ""} {
> + fail "$prefix: coverage summary not found; expected $shouldall"
> + set ok 0
> + }
> + }
> + set setup 1
> + set current [lindex $checks 0]
> + set checks [lreplace $checks 0 0]
> + set should [lindex $current 0]
> + set shouldt [lindex $current 1]
> + set shouldf [lindex $current 2]
> + set shouldall [lindex $current 3]
> + set newt [lindex $current 4]
> + set newf [lindex $current 5]
> +
> + if {$cond == $shouldall} {
> + set shouldall ""
> + } else {
> + fail "$prefix: unexpected summary - expected $shouldall, got $cond"
> + set ok 0
> + }
> + }
> + }
> +
> + if {$ok != 1} {
> + incr failed
> + }
> + }
> + close $fd
> + return $failed
> +}
> +
> #
> # verify-calls -- check that call return percentages are as expected
> #
> @@ -321,6 +567,7 @@ proc run-gcov { args } {
> set gcov_args ""
> set gcov_verify_calls 0
> set gcov_verify_branches 0
> + set gcov_verify_conditions 0
> set gcov_verify_lines 1
> set gcov_verify_intermediate 0
> set gcov_remove_gcda 0
> @@ -331,10 +578,13 @@ proc run-gcov { args } {
> set gcov_verify_calls 1
> } elseif { $a == "branches" } {
> set gcov_verify_branches 1
> + } elseif { $a == "conditions" } {
> + set gcov_verify_conditions 1
> } elseif { $a == "intermediate" } {
> set gcov_verify_intermediate 1
> set gcov_verify_calls 0
> set gcov_verify_branches 0
> + set gcov_verify_conditions 0
> set gcov_verify_lines 0
> } elseif { $a == "remove-gcda" } {
> set gcov_remove_gcda 1
> @@ -404,6 +654,11 @@ proc run-gcov { args } {
> } else {
> set bfailed 0
> }
> + if { $gcov_verify_conditions } {
> + set cdfailed [verify-conditions $testname $testcase $testcase.gcov]
> + } else {
> + set cdfailed 0
> + }
> if { $gcov_verify_calls } {
> set cfailed [verify-calls $testname $testcase $testcase.gcov]
> } else {
> @@ -418,12 +673,12 @@ proc run-gcov { args } {
>
> # Report whether the gcov test passed or failed. If there were
> # multiple failures then the message is a summary.
> - set tfailed [expr $lfailed + $bfailed + $cfailed + $ifailed]
> + set tfailed [expr $lfailed + $bfailed + $cdfailed + $cfailed + $ifailed]
> if { $xfailed } {
> setup_xfail "*-*-*"
> }
> if { $tfailed > 0 } {
> - fail "$testname gcov: $lfailed failures in line counts, $bfailed in branch percentages, $cfailed in return percentages, $ifailed in intermediate format"
> + fail "$testname gcov: $lfailed failures in line counts, $bfailed in branch percentages, $cdfailed in condition/decision, $cfailed in return percentages, $ifailed in intermediate format"
> if { $xfailed } {
> clean-gcov $testcase
> }
> diff --git a/gcc/tree-core.h b/gcc/tree-core.h
> index 65e51b939a2..44b9fa10431 100644
> --- a/gcc/tree-core.h
> +++ b/gcc/tree-core.h
> @@ -1582,6 +1582,9 @@ enum omp_clause_linear_kind
> struct GTY(()) tree_exp {
> struct tree_typed typed;
> location_t locus;
> + /* Discriminator for basic conditions in a Boolean expressions. Trees that
> + are operands of the same Boolean expression should have the same uid. */
> + unsigned condition_uid;
> tree GTY ((length ("TREE_OPERAND_LENGTH ((tree)&%h)"))) operands[1];
> };
>
> diff --git a/gcc/tree-profile.cc b/gcc/tree-profile.cc
> index 9c8fdb8b18f..263c2639280 100644
> --- a/gcc/tree-profile.cc
> +++ b/gcc/tree-profile.cc
> @@ -58,6 +58,7 @@ along with GCC; see the file COPYING3. If not see
> #include "alloc-pool.h"
> #include "symbol-summary.h"
> #include "symtab-thunks.h"
> +#include "cfganal.h"
>
> static GTY(()) tree gcov_type_node;
> static GTY(()) tree tree_interval_profiler_fn;
> @@ -108,6 +109,1055 @@ enum counter_update_method {
>
> static counter_update_method counter_update = COUNTER_UPDATE_SINGLE_THREAD;
>
> +/* These functions support measuring modified conditition/decision coverage
> + (MC/DC). MC/DC requires all of the below during testing:
> +
> + - Each entry and exit point is invoked
> + - Each decision takes every possible outcome
> + - Each condition in a decision takes every possible outcome
> + - Each condition in a decision is shown to independently affect the outcome
> + of the decision
> +
> + Independence of a condition is shown by recording it being evaluated to a
> + value (true/false) and not being made irrelevant ("masked") by a later term.
> + This feature adds some instrumentation code, a few bitwise operators, that
> + records the branches taken in conditions and applies a filter for the
> + masking effect. Masking is essentially short-circuiting in reverse: a
> + condition does not contribute to the outcome if it would short circuit the
> + (sub) expression if it was evaluated right-to-left, (_ && false) and (_ ||
> + true).
> +
> + The program is essentially rewritten this way:
> +
> + - if (a || b) { fn () }
> + + if (a) { _t |= 0x1; goto _then; }
> + + else { _f |= 0x1;
> + + if (b) { _t |= 0x2; _mask |= 0x1; goto _then; }
> + + else { _f |= 0x2; goto _else; }
> + + _then:
> + + _gcov_t |= (_t & _mask);
> + + _gcov_f |= (_f & _mask);
> + + fn (); goto _end;
> + + _else:
> + + _gcov_t |= (_t & _mask);
> + + _gcov_f |= (_f & _mask);
> + + fn ();
> + + _end:
> +
> + It is assumed the front end will provide discrimnators so that conditional
> + basic blocks (basic block with a conditional jump and outgoing true/false
> + edges) that belong to the same Boolean expression have the same
> + discriminator. Masking is determined by analyzing these expressions as a
> + reduced order binary decision diagram. */
> +namespace
> +{
> +/* Some context and reused instances between function calls. Large embedded
> + buffers are used to up-front request enough memory for most programs and
> + merge them into a single allocation at the cost of using more memory in the
> + average case. Some numbers from linux v5.13 which is assumed to be a
> + reasonably diverse code base: 75% of the functions in linux have less than
> + 16 nodes in the CFG and approx 2.5% have more than 64 nodes. The functions
> + that go beyond a few dozen nodes tend to be very large (>100) and so 64
> + seems like a good balance.
> +
> + This is really just a performance balance of the cost of allocation and
> + wasted memory. */
> +struct conds_ctx
> +{
> + /* This is both a reusable shared allocation which is also used to return
> + single expressions, which means it for most code should only hold a
> + couple of elements. */
> + auto_vec<basic_block, 64> blocks;
> +
> + /* Index for the topological order indexed by basic_block->index to an
> + ordering so that expression (a || b && c) => top_index[a] < top_index[b]
> + < top_index[c]. */
> + auto_vec<int, 256> top_index;
> +
> + /* Pre-allocate bitmaps and vectors for per-function book keeping. This is
> + pure instance reuse and the bitmaps carry no data between function
> + calls. */
> + auto_vec<basic_block, 64> B1;
> + auto_vec<basic_block, 64> B2;
> + auto_sbitmap G1;
> + auto_sbitmap G2;
> + auto_sbitmap G3;
> +
> + explicit conds_ctx (unsigned size) noexcept (true) : G1 (size), G2 (size),
> + G3 (size)
> + {
> + }
> +};
> +
> +/* Only instrument terms with fewer than number of bits in a (wide) gcov
> + integer, which is probably 64. The algorithm itself does not impose this
> + limitation, but it makes for a simpler implementation.
> +
> + * Allocating the output data structure (coverage_counter_alloc ()) can
> + assume pairs of gcov_type_unsigned and not use a separate length field.
> + * A pair gcov_type_unsigned can be used as accumulators.
> + * Updating accumulators is can use the bitwise operations |=, &= and not
> + custom operators that work for arbitrary-sized bit-sets.
> +
> + Most real-world code should be unaffected by this, but it is possible
> + (especially for generated code) to exceed this limit. */
> +#define CONDITIONS_MAX_TERMS (TYPE_PRECISION (gcov_type_node))
> +#define EDGE_CONDITION (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)
> +
> +/* Compare two basic blocks by their order in the expression i.e. for (a || b)
> + then topological_cmp (a, b, ...) < 0. The result is undefined if LHS, RHS
> + belong to different expressions. The TOP_INDEX argument should be the
> + top_index vector from ctx. */
> +int
> +topological_cmp (const void *lhs, const void *rhs, void *top_index)
> +{
> + const_basic_block l = *(const basic_block*) lhs;
> + const_basic_block r = *(const basic_block*) rhs;
> + const vec<int>* im = (const vec<int>*) top_index;
> + return (*im)[l->index] - (*im)[r->index];
> +}
> +
> +/* Find the index of NEEDLE in BLOCKS; return -1 if not found. This has two
> + uses, sometimes for the index and sometimes for set member checks. Sets are
> + typically very small (number of conditions, >8 is uncommon) so linear search
> + should be very fast. */
> +int
> +index_of (const basic_block needle, array_slice<basic_block> blocks)
> +{
> + for (size_t i = 0; i < blocks.size (); i++)
> + if (blocks[i] == needle)
> + return int (i);
> + return -1;
> +}
> +
> +/* Special cases of the single_*_p and single_*_edge functions in basic-block.h
> + that don't consider exception handling or other complex edges. This helps
> + create a view of the CFG with only normal edges - if a basic block has both
> + an outgoing fallthrough and exceptional edge, it should be considered a
> + single-successor. */
> +bool
> +single_p (const vec<edge, va_gc> *edges)
> +{
> + int n = EDGE_COUNT (edges);
> + if (n == 0)
> + return false;
> +
> + for (edge e : edges)
> + if (e->flags & EDGE_COMPLEX)
> + n -= 1;
> +
> + return n == 1;
> +}
> +
> +/* Get the single, non-complex edge. Behavior is undefined edges have more
> + than 1 non-complex edges. */
> +edge
> +single_edge (const vec<edge, va_gc> *edges)
> +{
> + gcc_checking_assert (single_p (edges));
> + for (edge e : edges)
> + {
> + if (e->flags & EDGE_COMPLEX)
> + continue;
> + return e;
> + }
> + return NULL;
> +}
> +
> +/* Sometimes, for example with function calls, goto labels, and C++
> + destructors, the CFG gets extra nodes that are essentially single-entry
> + single-exit in the middle of boolean expressions. For example:
> +
> + x || can_throw (y)
> +
> + A
> + /|
> + / |
> + B |
> + | |
> + C |
> + / \ |
> + / \|
> + F T
> +
> + Without the extra node inserted by the function + exception it becomes a
> + proper 2-term graph, not 2 single-term graphs.
> +
> + A
> + /|
> + C |
> + / \|
> + F T
> +
> + This function finds the source edge of these paths. This is often the
> + identity function. */
> +edge
> +contract_edge_up (edge e)
> +{
> + while (true)
> + {
> + basic_block src = e->src;
> + if (!single_p (src->preds))
> + return e;
> + if (!single_p (src->succs))
> + return e;
> + e = single_edge (src->preds);
> + }
> +}
> +
> +/* A simple struct for storing/returning outcome block pairs. Either both
> + blocks are set or both are NULL. */
> +struct outcomes
> +{
> + basic_block t = NULL;
> + basic_block f = NULL;
> +
> + operator bool () const noexcept (true)
> + {
> + return t && f;
> + }
> +};
> +
> +/* Get the true/false successors of a basic block. If b is not a conditional
> + block both edges are NULL. */
> +outcomes
> +conditional_succs (const basic_block b)
> +{
> + outcomes c;
> + for (edge e : b->succs)
> + {
> + if (e->flags & EDGE_TRUE_VALUE)
> + c.t = e->dest;
> + if (e->flags & EDGE_FALSE_VALUE)
> + c.f = e->dest;
> + }
> +
> + gcc_assert ((c.t && c.f) || (!c.t && !c.f));
> + return c;
> +}
> +
> +/* Get the index or offset of a conditional flag, 0 for true and 1 for false.
> + These indices carry no semantics but must be consistent as they are used to
> + index into data structures in code generation and gcov. */
> +unsigned
> +condition_index (unsigned flag)
> +{
> + return (flag & EDGE_CONDITION) == EDGE_TRUE_VALUE ? 0 : 1;
> +}
> +
> +/* Returns the condition identifier for the basic block if set, otherwise 0.
> + This is only meaningful in GIMPLE and is used for condition coverage.
> +
> + There may be conditions created that did not get an uid, such as those
> + implicitly created by destructors. We could include them in the condition
> + coverage for completeness (i.e. condition coverage implies (implicit) branch
> + coverage), but they have no natural buckets and should all be single-term.
> + For now these are ignored and given uid = 0, and branch coverage is left to
> + -fprofile-arcs.
> +
> + Under optimization, COND_EXPRs may be folded, replaced with switches,
> + min-max, etc., which leaves ghost identifiers in basic blocks that do not
> + end with a conditional jump. They are not really meaningful for condition
> + coverage anymore, but since coverage is unreliable under optimization anyway
> + this is not a big problem. */
> +unsigned
> +condition_uid (struct function *fn, basic_block b)
> +{
> + gimple *stmt = gsi_stmt (gsi_last_bb (b));
> + if (!safe_is_a<gcond *> (stmt))
> + return 0;
> +
> + unsigned *v = fn->cond_uids->get (as_a <gcond*> (stmt));
> + return v ? *v : 0;
> +}
> +
> +/* Compute the masking table.
> +
> + Masking and short circuiting are deeply connected - masking occurs when
> + control flow reaches a state that is also reachable with short circuiting.
> + In fact, masking corresponds to short circuiting for the reversed
> + expression. This means we can find the limits, the last term in preceeding
> + subexpressions, by following the edges that short circuit to the same
> + outcome. The algorithm treats the CFG as a reduced order binary decision
> + diagram (see Randall E. Bryant's Graph Based Algorithms for Boolean
> + Function Manipulation (1987)).
> +
> + In the simplest case a || b:
> +
> + a
> + |\
> + | b
> + |/ \
> + T F
> +
> + T has has multiple incoming edges and is the outcome of a short circuit,
> + with top = a, bot = b. The top node (a) is masked when the edge (b, T) is
> + taken.
> +
> + The names "top" and "bot" refer to a pair of nodes with a shared
> + successor. The top is always the node corresponding to the left-most
> + operand of the two, and it holds that top < bot in a topological ordering.
> +
> + Now consider (a && b) || (c && d) and its masking table:
> +
> + a
> + |\
> + b \
> + |\|
> + | c
> + | |\
> + | d \
> + |/ \|
> + T F
> +
> + a[0] = {}
> + a[1] = {}
> + b[0] = {a}
> + b[1] = {}
> + c[0] = {}
> + c[1] = {}
> + d[0] = {c}
> + d[1] = {a,b}
> +
> + Note that 0 and 1 are indices and not boolean values - a[0] is the index in
> + the masking vector when a takes the true edge.
> +
> + b[0] and d[0] are identical to the a || b example, and d[1] is the bot in
> + the triangle [d, b] -> T. b is the top node in the [d, b] relationship and
> + last term in (a && b). To find the other terms masked we use the fact that
> + all paths in an expression go through either of the outcomes, found by
> + collecting all non-complex edges that go out of the expression (the
> + neighborhood). In some cases the outgoing edge go through intermediate (or
> + bypass) nodes, and we collect these paths too (see contract_edge_up).
> +
> + We find the terms by marking the outcomes (in this case c, T) and walk the
> + predecessors starting at top (in this case b) and masking nodes when both
> + successors are marked.
> +
> + The masking table is represented as two bitfields per term in the expression
> + with the index corresponding to the term in the Boolean expression.
> + a || b && c becomes the term vector [a b c] and the masking table [a[0]
> + a[1] b[0] ...]. The kth bit of a masking vector is set if the the kth term
> + is masked by taking the edge.
> +
> + The out masks are in uint64_t (the practical maximum for gcov_type_node for
> + any target) as it has to be big enough to store the target size gcov types
> + independent of the host. */
> +void
> +masking_vectors (conds_ctx& ctx, array_slice<basic_block> blocks,
> + array_slice<sbitmap> maps, array_slice<uint64_t> masks)
> +{
> + gcc_assert (blocks.is_valid ());
> + gcc_assert (!blocks.empty ());
> + gcc_assert (maps.is_valid ());
> + gcc_assert (masks.is_valid ());
> + gcc_assert (sizeof (masks[0]) * BITS_PER_UNIT >= CONDITIONS_MAX_TERMS);
> +
> + if (bitmap_count_bits (maps[0]) == 1)
> + return;
> +
> + sbitmap marks = ctx.G1;
> + const sbitmap core = maps[0];
> + const sbitmap allg = maps[1];
> + vec<basic_block>& queue = ctx.B1;
> + vec<basic_block>& body = ctx.B2;
> + const vec<int>& top_index = ctx.top_index;
> +
> + /* Set up for the iteration - include the outcome nodes in the traversal.
> + The algorithm compares pairs of nodes and is not really sensitive to
> + traversal order, but need to maintain topological order because the
> + index of masking nodes maps to the index in the accumulators. We must
> + also check the incoming-to-outcome pairs. These edges may in turn be
> + split (this happens with labels on top of then/else blocks) so we must
> + follow any single-in single-out path. The non-condition blocks do not
> + have to be in order as they are non-condition blocks and will not be
> + considered for the set-bit index. */
> + body.truncate (0);
> + body.reserve (blocks.size () + 2);
> + for (const basic_block b : blocks)
> + if (bitmap_bit_p (core, b->index))
> + body.quick_push (b);
> +
> + for (basic_block b : blocks)
> + {
> + if (!bitmap_bit_p (core, b->index))
> + continue;
> +
> + for (edge e : b->succs)
> + {
> + if (e->flags & EDGE_COMPLEX)
> + continue;
> + if (bitmap_bit_p (allg, e->dest->index))
> + continue;
> + body.safe_push (e->dest);
> +
> + /* There may be multiple nodes between the condition edge and the
> + actual outcome, and we need to know when these paths join to
> + determine if there is short circuit/masking. This is
> + effectively creating a virtual edge from the condition node to
> + the real outcome. */
> + while (!(e->flags & EDGE_DFS_BACK) && single_p (e->dest->succs))
> + {
> + e = single_edge (e->dest->succs);
> + body.safe_push (e->dest);
> + }
> + }
> + }
> +
> + /* Find the masking. The leftmost element cannot mask anything, so
> + start at 1. */
> + for (size_t i = 1; i != body.length (); i++)
> + {
> + const basic_block b = body[i];
> + for (edge e1 : b->preds)
> + for (edge e2 : b->preds)
> + {
> + if (e1 == e2)
> + continue;
> + if ((e1->flags | e2->flags) & EDGE_COMPLEX)
> + continue;
> +
> + edge etop = contract_edge_up (e1);
> + edge ebot = contract_edge_up (e2);
> + gcc_assert (etop != ebot);
> +
> + const basic_block top = etop->src;
> + const basic_block bot = ebot->src;
> + const unsigned cond = etop->flags & ebot->flags & EDGE_CONDITION;
> + if (!cond)
> + continue;
> + if (top_index[top->index] > top_index[bot->index])
> + continue;
> + if (!bitmap_bit_p (core, top->index))
> + continue;
> + if (!bitmap_bit_p (core, bot->index))
> + continue;
> +
> + outcomes out = conditional_succs (top);
> + gcc_assert (out);
> + bitmap_clear (marks);
> + bitmap_set_bit (marks, out.t->index);
> + bitmap_set_bit (marks, out.f->index);
> + queue.truncate (0);
> + queue.safe_push (top);
> +
> + // The edge bot -> outcome triggers the masking
> + const int m = 2*index_of (bot, body) + condition_index (cond);
> + gcc_assert (m >= 0);
> + while (!queue.is_empty ())
> + {
> + basic_block q = queue.pop ();
> + /* q may have been processed & completed by being added to the
> + queue multiple times, so check that there is still work to
> + do before continuing. */
> + if (bitmap_bit_p (marks, q->index))
> + continue;
> +
> + outcomes succs = conditional_succs (q);
> + if (!bitmap_bit_p (marks, succs.t->index))
> + continue;
> + if (!bitmap_bit_p (marks, succs.f->index))
> + continue;
> +
> + const int index = index_of (q, body);
> + gcc_assert (index != -1);
> + masks[m] |= uint64_t (1) << index;
> + bitmap_set_bit (marks, q->index);
> +
> + for (edge e : q->preds)
> + {
> + e = contract_edge_up (e);
> + if (e->flags & EDGE_DFS_BACK)
> + continue;
> + if (bitmap_bit_p (marks, e->src->index))
> + continue;
> + if (!bitmap_bit_p (core, e->src->index))
> + continue;
> + queue.safe_push (e->src);
> + }
> + }
> + }
> + }
> +}
> +
> +/* Emit LHS = RHS on edges. This is just a short hand that automates the
> + building of the assign and immediately puts it on the edge, which becomes
> + noisy. */
> +tree
> +emit_assign (edge e, tree lhs, tree rhs)
> +{
> + gassign *w = gimple_build_assign (lhs, rhs);
> + gsi_insert_on_edge (e, w);
> + return lhs;
> +}
> +
> +/* Emit lhs = RHS on edges. The lhs is created. */
> +tree
> +emit_assign (edge e, tree rhs)
> +{
> + return emit_assign (e, make_ssa_name (gcov_type_node), rhs);
> +}
> +
> +/* Emit LHS = OP1 <OP> OP2 on edges. */
> +tree
> +emit_bitwise_op (edge e, tree op1, tree_code op, tree op2 = NULL_TREE)
> +{
> + tree lhs = make_ssa_name (gcov_type_node);
> + gassign *w = gimple_build_assign (lhs, op, op1, op2);
> + gsi_insert_on_edge (e, w);
> + return lhs;
> +}
> +
> +/* Visitor for make_top_index. */
> +void
> +make_top_index_visit (basic_block b, vec<basic_block>& L, vec<int>& marks)
> +{
> + if (marks[b->index])
> + return;
> +
> + /* Follow the false edge first, if it exists, so that true paths are given
> + the lower index in the ordering. Any iteration order
> + would yield a valid and useful topological ordering, but making sure the
> + true branch has the lower index first makes reporting work better for
> + expressions with ternaries. Walk the false branch first because the
> + array will be reversed to finalize the topological order.
> +
> + With the wrong ordering (a ? b : c) && d could become [a c b d], but the
> + (expected) order is really [a b c d]. */
> +
> + const unsigned false_fwd = EDGE_DFS_BACK | EDGE_FALSE_VALUE;
> + for (edge e : b->succs)
> + if ((e->flags & false_fwd) == EDGE_FALSE_VALUE)
> + make_top_index_visit (e->dest, L, marks);
> +
> + for (edge e : b->succs)
> + if (!(e->flags & false_fwd))
> + make_top_index_visit (e->dest, L, marks);
> +
> + marks[b->index] = 1;
> + L.quick_push (b);
> +}
> +
> +/* Find a topological sorting of the blocks in a function so that left operands
> + are before right operands including subexpressions. Sorting on block index
> + does not guarantee this property and the syntactical order of terms is very
> + important to the condition coverage. The sorting algorithm is from Cormen
> + et al (2001) but with back-edges ignored and thus there is no need for
> + temporary marks (for cycle detection). The L argument is a buffer/working
> + memory, and the output will be written to TOP_INDEX.
> +
> + For the expression (a || (b && c) || d) the blocks should be [a b c d]. */
> +void
> +make_top_index (array_slice<basic_block> blocks, vec<basic_block>& L,
> + vec<int>& top_index)
> +{
> + L.truncate (0);
> + L.reserve (blocks.size ());
> +
> + /* Use of the output map as a temporary for tracking visited status. */
> + top_index.truncate (0);
> + top_index.safe_grow_cleared (blocks.size ());
> + for (const basic_block b : blocks)
> + make_top_index_visit (b, L, top_index);
> +
> + /* Insert canaries - if there are unreachable nodes (for example infinite
> + loops) then the unreachable nodes should never be needed for comparison,
> + and L.length () < max_index. An index mapping should also never be
> + recorded twice. */
> + for (unsigned i = 0; i != top_index.length (); i++)
> + top_index[i] = -1;
> +
> + gcc_assert (blocks.size () == L.length ());
> + L.reverse ();
> + const unsigned nblocks = L.length ();
> + for (unsigned i = 0; i != nblocks; i++)
> + {
> + gcc_assert (L[i]->index != -1);
> + top_index[L[i]->index] = int (i);
> + }
> +}
> +
> +/* Find all nodes including non-conditions in a Boolean expression. We need to
> + know the paths through the expression so that the masking and
> + instrumentation phases can limit searches and know what subgraphs must be
> + threaded through, but not counted, such as the (b || c) in
> + a && fn (b || c) && d.
> +
> + It is essentially the intersection of downwards paths from the expression
> + nodes EXPR to the post-dominator and upwards from the post-dominator.
> + Finding the dominator is slightly more involved than picking the first/last,
> + particularly under optimization, because both incoming and outgoing paths
> + may have multiple entries/exits.
> +
> + It is assumed GRAPH is an array_slice of the basic blocks of this function
> + sorted by the basic block index. */
> +vec<basic_block>&
> +paths_between (conds_ctx &ctx, array_slice<basic_block> graph,
> + const vec<basic_block>& expr)
> +{
> + if (expr.length () == 1)
> + {
> + ctx.blocks.truncate (0);
> + ctx.blocks.safe_push (expr[0]);
> + return ctx.blocks;
> + }
> +
> + basic_block dom;
> + sbitmap up = ctx.G1;
> + sbitmap down = ctx.G2;
> + sbitmap paths = ctx.G3;
> + vec<basic_block>& queue = ctx.B1;
> +
> + queue.truncate (0);
> + bitmap_clear (down);
> + dom = get_immediate_dominator (CDI_POST_DOMINATORS, expr[0]);
> + for (basic_block b : expr)
> + if (dom != b)
> + dom = nearest_common_dominator (CDI_POST_DOMINATORS, dom, b);
> + queue.safe_splice (expr);
> + while (!queue.is_empty ())
> + {
> + basic_block b = queue.pop ();
> + if (!bitmap_set_bit (down, b->index))
> + continue;
> + if (b == dom)
> + continue;
> + for (edge e : b->succs)
> + if (!(e->flags & (EDGE_COMPLEX | EDGE_DFS_BACK)))
> + queue.safe_push (e->dest);
> + }
> +
> + queue.truncate (0);
> + bitmap_clear (up);
> + dom = expr[0];
> + for (basic_block b : expr)
> + if (dom != b)
> + dom = nearest_common_dominator (CDI_DOMINATORS, dom, b);
> + queue.safe_splice (expr);
> + while (!queue.is_empty ())
> + {
> + basic_block b = queue.pop ();
> + if (!bitmap_set_bit (up, b->index))
> + continue;
> + if (b == dom)
> + continue;
> + for (edge e : b->preds)
> + if (!(e->flags & (EDGE_COMPLEX | EDGE_DFS_BACK)))
> + queue.safe_push (e->src);
> + }
> +
> + bitmap_and (paths, up, down);
> + vec<basic_block>& blocks = ctx.blocks;
> + blocks.truncate (0);
> + blocks.reserve (graph.size ());
> + sbitmap_iterator itr;
> + unsigned index;
> + EXECUTE_IF_SET_IN_BITMAP (paths, 0, index, itr)
> + blocks.quick_push (graph[index]);
> + return blocks;
> +}
> +
> +}
> +
> +/* Context object for the condition coverage. This stores conds_ctx (the
> + buffers reused when analyzing the cfg) and the output arrays. This is
> + designed to be heap allocated and aggressively preallocates large buffers to
> + avoid having to reallocate for most programs. */
> +struct condcov
> +{
> + explicit condcov (unsigned nblocks) noexcept (true) : ctx (nblocks),
> + m_maps (sbitmap_vector_alloc (2 * nblocks, nblocks))
> + {
> + bitmap_vector_clear (m_maps, 2 * nblocks);
> + }
> + auto_vec<size_t, 128> m_index;
> + auto_vec<basic_block, 256> m_blocks;
> + auto_vec<uint64_t, 512> m_masks;
> + conds_ctx ctx;
> + sbitmap *m_maps;
> +};
> +
> +/* Get the length, that is the number of Boolean expression found. cov_length
> + is the one-past index for cov_{blocks,masks,maps}. */
> +size_t
> +cov_length (const struct condcov* cov)
> +{
> + if (cov->m_index.is_empty ())
> + return 0;
> + return cov->m_index.length () - 1;
> +}
> +
> +/* The subgraph, exluding intermediates, for the nth Boolean expression. */
> +array_slice<basic_block>
> +cov_blocks (struct condcov* cov, size_t n)
> +{
> + if (n >= cov->m_index.length ())
> + return array_slice<basic_block>::invalid ();
> +
> + basic_block *begin = cov->m_blocks.begin () + cov->m_index[n];
> + basic_block *end = cov->m_blocks.begin () + cov->m_index[n + 1];
> + return array_slice<basic_block> (begin, end - begin);
> +}
> +
> +/* The masks for the nth Boolean expression. */
> +array_slice<uint64_t>
> +cov_masks (struct condcov* cov, size_t n)
> +{
> + if (n >= cov->m_index.length ())
> + return array_slice<uint64_t>::invalid ();
> +
> + uint64_t *begin = cov->m_masks.begin () + 2*cov->m_index[n];
> + uint64_t *end = cov->m_masks.begin () + 2*cov->m_index[n + 1];
> + return array_slice<uint64_t> (begin, end - begin);
> +}
> +
> +/* The maps for the nth Boolean expression. */
> +array_slice<sbitmap>
> +cov_maps (struct condcov* cov, size_t n)
> +{
> + if (n >= cov->m_index.length ())
> + return array_slice<sbitmap>::invalid ();
> +
> + sbitmap *begin = cov->m_maps + 2*n;
> + sbitmap *end = begin + 2;
> + return array_slice<sbitmap> (begin, end - begin);
> +}
> +
> +/* Deleter for condcov. */
> +void
> +cov_free (struct condcov* cov)
> +{
> + sbitmap_vector_free (cov->m_maps);
> + delete cov;
> +}
> +
> +/* Condition coverage (MC/DC)
> +
> + Whalen, Heimdahl, De Silva in "Efficient Test Coverage Measurement for
> + MC/DC" describe an algorithm for modified condition/decision coverage based
> + on AST analysis. This algorithm does analyzes the control flow graph
> + (interpreted as a binary decision diagram) to determine the masking vectors.
> + The individual phases are described in more detail closer to the
> + implementation.
> +
> + The coverage only considers the positions, not the symbols, in a
> + conditional, e.g. !A || (!B && A) is a 3-term conditional even though A
> + appears twice. Subexpressions have no effect on term ordering:
> + (a && (b || (c && d)) || e) comes out as [a b c d e]. Functions whose
> + arguments are Boolean expressions are treated as separate expressions, that
> + is, a && fn (b || c) && d is treated as [a _fn d] and [b c], not [a b c d].
> +
> + The output for gcov is a vector of pairs of unsigned integers, interpreted
> + as bit-sets, where the bit index corresponds to the index of the condition
> + in the expression.
> +
> + The returned condcov should be released by the caller with cov_free. */
> +struct condcov*
> +find_conditions (struct function *fn)
> +{
> + mark_dfs_back_edges (fn);
> + const bool have_dom = dom_info_available_p (fn, CDI_DOMINATORS);
> + const bool have_post_dom = dom_info_available_p (fn, CDI_POST_DOMINATORS);
> + if (!have_dom)
> + calculate_dominance_info (CDI_DOMINATORS);
> + if (!have_post_dom)
> + calculate_dominance_info (CDI_POST_DOMINATORS);
> +
> + const unsigned nblocks = n_basic_blocks_for_fn (fn);
> + basic_block *fnblocksp = basic_block_info_for_fn (fn)->address ();
> + condcov *cov = new condcov (nblocks);
> + conds_ctx& ctx = cov->ctx;
> + array_slice<basic_block> fnblocks (fnblocksp, nblocks);
> + make_top_index (fnblocks, ctx.B1, ctx.top_index);
> +
> + /* Bin the Boolean expressions so that exprs[id] -> [x1, x2, ...]. */
> + hash_map<int_hash<unsigned, 0>, vec<basic_block>> exprs;
> + for (basic_block b : fnblocks)
> + {
> + const unsigned uid = condition_uid (fn, b);
> + if (uid == 0)
> + continue;
> + exprs.get_or_insert (uid).safe_push (b);
> + }
> +
> + /* Visit all reachable nodes and collect conditions. Topological order is
> + important so the first node of a boolean expression is visited first
> + (it will mark subsequent terms). */
> + cov->m_index.safe_push (0);
> + for (auto expr : exprs)
> + {
> + vec<basic_block>& conds = expr.second;
> + if (conds.length () > CONDITIONS_MAX_TERMS)
> + {
> + location_t loc = gimple_location (gsi_stmt (gsi_last_bb (conds[0])));
> + warning_at (loc, OPT_Wcoverage_too_many_conditions,
> + "Too many conditions (found %u); giving up coverage",
> + conds.length ());
> + continue;
> + }
> + conds.sort (topological_cmp, &ctx.top_index);
> + vec<basic_block>& subgraph = paths_between (ctx, fnblocks, conds);
> + subgraph.sort (topological_cmp, &ctx.top_index);
> + const unsigned index = cov->m_index.length () - 1;
> + sbitmap condm = cov->m_maps[0 + 2*index];
> + sbitmap subgm = cov->m_maps[1 + 2*index];
> + for (basic_block b : conds)
> + bitmap_set_bit (condm, b->index);
> + for (basic_block b : subgraph)
> + bitmap_set_bit (subgm, b->index);
> + cov->m_blocks.safe_splice (subgraph);
> + cov->m_index.safe_push (cov->m_blocks.length ());
> + }
> +
> + if (!have_dom)
> + free_dominance_info (fn, CDI_DOMINATORS);
> + if (!have_post_dom)
> + free_dominance_info (fn, CDI_POST_DOMINATORS);
> +
> + cov->m_masks.safe_grow_cleared (2 * cov->m_index.last ());
> + const size_t length = cov_length (cov);
> + for (size_t i = 0; i != length; i++)
> + masking_vectors (ctx, cov_blocks (cov, i), cov_maps (cov, i),
> + cov_masks (cov, i));
> +
> + return cov;
> +}
> +
> +namespace
> +{
> +
> +/* Stores the incoming edge and previous counters (in SSA form) on that edge
> + for the node e->deston that edge for the node e->dest. The counters record
> + the seen-true (0), seen-false (1), and current-mask (2). They are stored in
> + an array rather than proper members for access-by-index as the code paths
> + tend to be identical for the different counters. */
> +struct counters
> +{
> + edge e;
> + tree counter[3];
> + tree& operator [] (size_t i) { return counter[i]; }
> +};
> +
> +/* Find the counters for the incoming edge e, or NULL if the edge has not been
> + recorded (could be for complex incoming edges). */
> +counters*
> +find_counters (vec<counters>& candidates, edge e)
> +{
> + for (counters& candidate : candidates)
> + if (candidate.e == e)
> + return &candidate;
> + return NULL;
> +}
> +
> +/* Resolve the SSA for a specific counter KIND. If it is not modified by any
> + incoming edges, simply forward it, otherwise create a phi node of all the
> + candidate counters and return it. */
> +tree
> +resolve_counter (vec<counters>& cands, size_t kind)
> +{
> + gcc_assert (!cands.is_empty ());
> + gcc_assert (kind < 3);
> +
> + counters& fst = cands[0];
> +
> + if (!fst.e || fst.e->dest->preds->length () == 1)
> + {
> + gcc_assert (cands.length () == 1);
> + return fst[kind];
> + }
> +
> + tree zero0 = build_int_cst (gcov_type_node, 0);
> + tree ssa = make_ssa_name (gcov_type_node);
> + gphi *phi = create_phi_node (ssa, fst.e->dest);
> + for (edge e : fst.e->dest->preds)
> + {
> + counters *prev = find_counters (cands, e);
> + if (prev)
> + add_phi_arg (phi, (*prev)[kind], e, UNKNOWN_LOCATION);
> + else
> + {
> + tree zero = make_ssa_name (gcov_type_node);
> + gimple_stmt_iterator gsi = gsi_after_labels (e->src);
> + gassign *set = gimple_build_assign (zero, zero0);
> + gsi_insert_before (&gsi, set, GSI_NEW_STMT);
> + add_phi_arg (phi, zero, e, UNKNOWN_LOCATION);
> + }
> + }
> + return ssa;
> +}
> +
> +/* Resolve all the counters for a node. Note that the edge is undefined, as
> + the counters are intended to form the base to push to the successors, and
> + because the is only meaningful for nodes with a single predecessor. */
> +counters
> +resolve_counters (vec<counters>& cands)
> +{
> + counters next;
> + next[0] = resolve_counter (cands, 0);
> + next[1] = resolve_counter (cands, 1);
> + next[2] = resolve_counter (cands, 2);
> + return next;
> +}
> +
> +}
> +
> +/* Add instrumentation to a decision subgraph. EXPR should be the
> + (topologically sorted) block of nodes returned by cov_blocks, MAPS the
> + bitmaps returned by cov_maps, and MASKS the block of bitsets returned by
> + cov_masks. CONDNO should be the index of this condition in the function,
> + i.e. the same argument given to cov_{masks,graphs}. EXPR may contain nodes
> + in-between the conditions, e.g. when an operand contains a function call,
> + or there is a setjmp and the cfg is filled with complex edges.
> +
> + Every node is annotated with three counters; the true, false, and mask
> + value. First, walk the graph and determine what if there are multiple
> + possible values for either accumulator depending on the path taken, in which
> + case a phi node is created and registered as the accumulator. Then, those
> + values are pushed as accumulators to the immediate successors. For some
> + very particular programs there may be multiple paths into the expression
> + (e.g. when prior terms are determined by a surrounding conditional) in which
> + case the default zero-counter is pushed, otherwise all predecessors will
> + have been considered before the successor because of topologically ordered
> + traversal. Finally, expr is traversed again to look for edges to the
> + outcomes, that is, edges with a destination outside of expr, and the local
> + accumulators are flushed to the global gcov counters on these edges. In
> + some cases there are edge splits that cause 3+ edges to the two outcome
> + nodes.
> +
> + If a complex edge is taken (e.g. on a longjmp) the accumulators are
> + attempted poisoned so that there would be no change to the global counters,
> + but this has proven unreliable in the presence of undefined behavior, see
> + the setjmp003 test.
> +
> + It is important that the flushes happen on the basic condition outgoing
> + edge, otherwise flushes could be lost to exception handling or other
> + abnormal control flow. */
> +size_t
> +instrument_decisions (array_slice<basic_block> expr, size_t condno,
> + array_slice<sbitmap> maps, array_slice<uint64_t> masks)
> +{
> + tree zero = build_int_cst (gcov_type_node, 0);
> + tree poison = build_int_cst (gcov_type_node, ~0ULL);
> + const sbitmap core = maps[0];
> + const sbitmap allg = maps[1];
> +
> + hash_map<basic_block, vec<counters>> table;
> + counters zerocounter;
> + zerocounter.e = NULL;
> + zerocounter[0] = zero;
> + zerocounter[1] = zero;
> + zerocounter[2] = zero;
> +
> + unsigned xi = 0;
> + tree rhs = build_int_cst (gcov_type_node, 1ULL << xi);
> + for (basic_block current : expr)
> + {
> + vec<counters>& candidates = table.get_or_insert (current);
> + if (candidates.is_empty ())
> + candidates.safe_push (zerocounter);
> + counters prev = resolve_counters (candidates);
> +
> + int increment = 0;
> + for (edge e : current->succs)
> + {
> + counters next = prev;
> + next.e = e;
> +
> + if (bitmap_bit_p (core, e->src->index) && (e->flags & EDGE_CONDITION))
> + {
> + const int k = condition_index (e->flags);
> + next[k] = emit_bitwise_op (e, prev[k], BIT_IOR_EXPR, rhs);
> + if (masks[2*xi + k])
> + {
> + tree m = build_int_cst (gcov_type_node, masks[2*xi + k]);
> + next[2] = emit_bitwise_op (e, prev[2], BIT_IOR_EXPR, m);
> + }
> + increment = 1;
> + }
> + else if (e->flags & EDGE_COMPLEX)
> + {
> + /* A complex edge has been taken - wipe the accumulators and
> + poison the mask so that this path does not contribute to
> + coverage. */
> + next[0] = poison;
> + next[1] = poison;
> + next[2] = poison;
> + }
> + table.get_or_insert (e->dest).safe_push (next);
> + }
> + xi += increment;
> + if (increment)
> + rhs = build_int_cst (gcov_type_node, 1ULL << xi);
> + }
> +
> + gcc_assert (xi == bitmap_count_bits (core));
> +
> + const tree relaxed = build_int_cst (integer_type_node, MEMMODEL_RELAXED);
> + const bool atomic = flag_profile_update == PROFILE_UPDATE_ATOMIC;
> + const tree atomic_ior = builtin_decl_explicit
> + (TYPE_PRECISION (gcov_type_node) > 32
> + ? BUILT_IN_ATOMIC_FETCH_OR_8
> + : BUILT_IN_ATOMIC_FETCH_OR_4);
> +
> + /* Flush to the gcov accumulators. */
> + for (const basic_block b : expr)
> + {
> + if (!bitmap_bit_p (core, b->index))
> + continue;
> +
> + for (edge e : b->succs)
> + {
> + /* Flush the accumulators on leaving the Boolean function. The
> + destination may be inside the function only when it returns to
> + the loop header, such as do { ... } while (x); */
> + if (bitmap_bit_p (allg, e->dest->index)) {
> + if (!(e->flags & EDGE_DFS_BACK))
> + continue;
> + if (e->dest != expr[0])
> + continue;
> + }
> +
> + vec<counters> *cands = table.get (e->dest);
> + gcc_assert (cands);
> + counters *prevp = find_counters (*cands, e);
> + gcc_assert (prevp);
> + counters prev = *prevp;
> +
> + /* _true &= ~mask, _false &= ~mask */
> + counters next;
> + next[2] = emit_bitwise_op (e, prev[2], BIT_NOT_EXPR);
> + next[0] = emit_bitwise_op (e, prev[0], BIT_AND_EXPR, next[2]);
> + next[1] = emit_bitwise_op (e, prev[1], BIT_AND_EXPR, next[2]);
> +
> + /* _global_true |= _true, _global_false |= _false */
> + for (size_t k = 0; k != 2; ++k)
> + {
> + tree ref = tree_coverage_counter_ref (GCOV_COUNTER_CONDS,
> + 2*condno + k);
> + if (atomic)
> + {
> + ref = unshare_expr (ref);
> + gcall *flush = gimple_build_call (atomic_ior, 3,
> + build_addr (ref),
> + next[k], relaxed);
> + gsi_insert_on_edge (e, flush);
> + }
> + else
> + {
> + tree get = emit_assign (e, ref);
> + tree put = emit_bitwise_op (e, next[k], BIT_IOR_EXPR, get);
> + emit_assign (e, unshare_expr (ref), put);
> + }
> + }
> + }
> + }
> +
> + return xi;
> +}
> +
> +#undef CONDITIONS_MAX_TERMS
> +#undef EDGE_CONDITION
> +
> /* Do initialization work for the edge profiler. */
>
> /* Add code:
> @@ -837,7 +1887,7 @@ tree_profiling (void)
> thunk = true;
> /* When generate profile, expand thunk to gimple so it can be
> instrumented same way as other functions. */
> - if (profile_arc_flag)
> + if (profile_arc_flag || condition_coverage_flag)
> expand_thunk (node, false, true);
> /* Read cgraph profile but keep function as thunk at profile-use
> time. */
> @@ -882,7 +1932,7 @@ tree_profiling (void)
> release_profile_file_filtering ();
>
> /* Drop pure/const flags from instrumented functions. */
> - if (profile_arc_flag || flag_test_coverage)
> + if (profile_arc_flag || condition_coverage_flag || flag_test_coverage)
> FOR_EACH_DEFINED_FUNCTION (node)
> {
> if (!gimple_has_body_p (node->decl)
> @@ -914,7 +1964,7 @@ tree_profiling (void)
>
> push_cfun (DECL_STRUCT_FUNCTION (node->decl));
>
> - if (profile_arc_flag || flag_test_coverage)
> + if (profile_arc_flag || condition_coverage_flag || flag_test_coverage)
> FOR_EACH_BB_FN (bb, cfun)
> {
> gimple_stmt_iterator gsi;
> @@ -999,7 +2049,7 @@ pass_ipa_tree_profile::gate (function *)
> disabled. */
> return (!in_lto_p && !flag_auto_profile
> && (flag_branch_probabilities || flag_test_coverage
> - || profile_arc_flag));
> + || profile_arc_flag || condition_coverage_flag));
> }
>
> } // anon namespace
> diff --git a/gcc/tree.h b/gcc/tree.h
> index 086b55f0375..f4186a72b5c 100644
> --- a/gcc/tree.h
> +++ b/gcc/tree.h
> @@ -1358,6 +1358,10 @@ class auto_suppress_location_wrappers
> ~auto_suppress_location_wrappers () { --suppress_location_wrappers; }
> };
>
> +/* COND_EXPR identificer/discriminator accessors. */
> +#define SET_EXPR_UID(t, v) EXPR_CHECK ((t))->exp.condition_uid = (v)
> +#define EXPR_COND_UID(t) EXPR_CHECK ((t))->exp.condition_uid
> +
> /* In a TARGET_EXPR node. */
> #define TARGET_EXPR_SLOT(NODE) TREE_OPERAND_CHECK_CODE (NODE, TARGET_EXPR, 0)
> #define TARGET_EXPR_INITIAL(NODE) TREE_OPERAND_CHECK_CODE (NODE, TARGET_EXPR, 1)
> diff --git a/libgcc/libgcov-merge.c b/libgcc/libgcov-merge.c
> index 5d6e17d1483..eed3556373b 100644
> --- a/libgcc/libgcov-merge.c
> +++ b/libgcc/libgcov-merge.c
> @@ -33,6 +33,11 @@ void __gcov_merge_add (gcov_type *counters __attribute__ ((unused)),
> unsigned n_counters __attribute__ ((unused))) {}
> #endif
>
> +#ifdef L_gcov_merge_ior
> +void __gcov_merge_ior (gcov_type *counters __attribute__ ((unused)),
> + unsigned n_counters __attribute__ ((unused))) {}
> +#endif
> +
> #ifdef L_gcov_merge_topn
> void __gcov_merge_topn (gcov_type *counters __attribute__ ((unused)),
> unsigned n_counters __attribute__ ((unused))) {}
next prev parent reply other threads:[~2024-03-12 20:40 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-23 11:17 Jørgen Kvalsvik
2024-02-23 11:18 ` [PATCH v10 2/2] Add gcov MC/DC tests for GDC Jørgen Kvalsvik
2024-02-23 11:44 ` Iain Buclaw
2024-04-05 8:34 ` [PATCH] testsuite: Fix up error on gcov1.d Jakub Jelinek
2024-04-05 8:57 ` Richard Biener
2024-03-12 20:40 ` Jørgen Kvalsvik [this message]
2024-03-21 12:23 ` Ping^2 [PATCH v10 1/2] Add condition coverage (MC/DC) Jørgen Kvalsvik
2024-04-03 7:32 ` Ping^3 " Jørgen Kvalsvik
2024-04-04 12:10 ` Jan Hubicka
2024-04-04 12:54 ` Jørgen Kvalsvik
2024-04-04 13:56 ` Jan Hubicka
2024-04-05 13:00 ` Rainer Orth
2024-04-05 13:34 ` Jørgen Kvalsvik
2024-04-05 14:03 ` H.J. Lu
2024-04-15 8:53 ` Rainer Orth
2024-04-15 9:03 ` Jørgen Kvalsvik
2024-04-15 9:39 ` Jørgen Kvalsvik
2024-04-15 11:18 ` Rainer Orth
2024-04-15 11:34 ` Jørgen Kvalsvik
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ac7ac89b-b495-42a2-8a8e-95f4438ee378@lambda.is \
--to=j@lambda.is \
--cc=gcc-patches@gcc.gnu.org \
--cc=hubicka@ucw.cz \
--cc=richard.guenther@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).