From: "Jørgen Kvalsvik" <jorgen.kvalsvik@woven-planet.global>
To: gcc-patches@gcc.gnu.org
Cc: mliska@suse.cz
Subject: Ping [PATCH] Add condition coverage profiling
Date: Tue, 25 Oct 2022 08:33:42 +0200 [thread overview]
Message-ID: <b920e748-b649-d35a-8100-4c0a6a09581a@woven-planet.global> (raw)
In-Reply-To: <20221012101619.7221-1-jorgen.kvalsvik@woven-planet.global>
On 12/10/2022 12:16, Jørgen Kvalsvik wrote:
> This patch adds support in gcc+gcov for modified condition/decision
> coverage (MC/DC) with the -fprofile-conditions flag. MC/DC is a type of
> test/code coverage and it is particularly important in the avation and
> automotive industries for safety-critical applications. MC/DC it is
> required for 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
>
> Wahlen, Heimdahl, and De Silva "Efficient Test Coverage Measurement for
> MC/DC" describes an algorithm for adding instrumentation by carrying
> over information from the AST, but my algorithm analyses the the control
> flow graph to instrument for coverage. This has the benefit of being
> programming language independent and faithful to compiler decisions
> and transformations, although I have only tested it on constructs in C
> and C++, see testsuite/gcc.misc-tests and testsuite/g++.dg.
>
> Like Wahlen et al this implementation records coverage in fixed-size
> bitsets which gcov knows how to interpret. This is very fast, but
> introduces a limit on the number of terms in a single boolean
> expression, the number of bits in a gcov_unsigned_type (which is
> typedef'd to uint64_t), so for most practical purposes this would be
> acceptable. This limitation is in the implementation and not the
> algorithm, so support for more conditions can be added by also
> introducing arbitrary-sized bitsets.
>
> For space overhead, the instrumentation needs two accumulators
> (gcov_unsigned_type) per condition in the program which will be written
> to the gcov file. In addition, every function gets a pair of local
> accumulators, but these accmulators are reused between conditions in the
> same function.
>
> For time overhead, there is a zeroing of the local accumulators for
> every condition and one or two bitwise operation on every edge taken in
> the an expression.
>
> 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)
> condition outcomes 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
> ]
> }
> ],
>
> Some expressions, mostly those without else-blocks, are effectively
> "rewritten" in the CFG construction making the algorithm unable to
> distinguish them:
>
> and.c:
>
> if (a && b && c)
> x = 1;
>
> ifs.c:
>
> if (a)
> if (b)
> if (c)
> x = 1;
>
> gcc will build the same graph for both these programs, and gcov will
> report boths as 3-term expressions. It is vital that it is not
> interpreted the other way around (which is consistent with the shape of
> the graph) because otherwise the masking would be wrong for the and.c
> program which is a more severe error. While surprising, users would
> probably expect some minor rewriting of semantically-identical
> expressions.
>
> and.c.gcov:
> #####: 2: if (a && b && c)
> decisions covered 6/6
> #####: 3: x = 1;
>
> ifs.c.gcov:
> #####: 2: if (a)
> #####: 3: if (b)
> #####: 4: if (c)
> #####: 5: x = 1;
> condition outcomes covered 6/6
>
> Adding else clauses alters the program (ifs.c can have 3 elses, and.c
> only 1) and coverage becomes less surprising
>
> ifs.c.gcov:
> #####: 2: if (a)
> condition outcomes covered 2/2
> #####: 4: {
> #####: 4: if (b)
> condition outcomes covered 2/2
> 5: {
> #####: 6: if (c)
> condition outcomes covered 2/2
> #####: 7: x = 1;
> #####: 8: }
> #####: 9: else
> #####: 10: x = 2;
> #####: 11: }
> #####: 12: else
> #####: 13: x = 3;
>
> Since the algorithm works on CFGs, it cannot detect some ternary
> operator introduced conditionals. For example, int x = a ? 0 : 1 in
> gimple becomes _x = (_a == 0). From source you would expect coverage,
> but it gets neither branch nor condition coverage. For completeness, it
> could be achieved by scanning all gimple statements for such
> comparisons, and insert an extra instruction for recording the outcome.
>
> The test suite contains a lot of small programs 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.
>
> Alternative author email: Jørgen Kvalsvik <j@lambda.is>
>
> gcc/ChangeLog:
>
> * builtins.cc (expand_builtin_fork_or_exec): Check
> profile_condition_flag.
> * collect2.cc (main): Add -fno-profile-conditions to OBSTACK.
> * common.opt: Add new options -fprofile-conditions and
> * doc/gcov.texi: Add --conditions documentation.
> * doc/invoke.texi: Add -fprofile-conditions documentation.
> * gcc.cc: Link gcov on -fprofile-conditions.
> * gcov-counter.def (GCOV_COUNTER_CONDS): New.
> * gcov-dump.cc (tag_conditions): New.
> * gcov-io.h (GCOV_TAG_CONDS): New.
> (GCOV_TAG_CONDS_LENGTH): Likewise.
> (GCOV_TAG_CONDS_NUM): Likewise.
> * 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 conditions counters.
> (read_count_file): Read conditions counters.
> (file_summary): Print conditions.
> (accumulate_line_info): Accumulate conditions.
> (output_line_details): Print conditions.
> * ipa-inline.cc (can_early_inline_edge_p): Check
> profile_condition_flag.
> * ipa-split.cc (pass_split_functions::gate): Likewise.
> * passes.cc (finish_optimization_passes): Likewise.
> * profile.cc (find_conditions): New declaration.
> (cov_length): Likewise.
> (cov_blocks): Likewise.
> (cov_masks): 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-profile.cc (struct conds_ctx): New.
> (CONDITIONS_MAX_TERMS): New.
> (EDGE_CONDITION): New.
> (cmp_index_map): New.
> (index_of): New.
> (block_conditional_p): New.
> (edge_conditional_p): New.
> (single): New.
> (single_edge): New.
> (contract_edge): New.
> (contract_edge_up): New.
> (merge_split_outcome): New.
> (ancestors_of): New.
> (struct outcomes): New.
> (conditional_succs): New.
> (condition_index): New.
> (masking_vectors): New.
> (cond_reachable_from): New.
> (neighborhood): New.
> (isolate_expression): New.
> (emit_bitwise_op): New.
> (make_index_map_visit): New.
> (make_index_map): New.
> (collect_conditions): New.
> (yes): New.
> (struct condcov): New.
> (cov_length): New.
> (cov_blocks): New.
> (cov_masks): New.
> (cov_free): New.
> (find_conditions): New.
> (instrument_decisions): New.
> (tree_profiling): Check profile_condition_flag.
> (pass_ipa_tree_profile::gate): Likewise.
>
> libgcc/ChangeLog:
>
> * libgcov-merge.c (__gcov_merge_ior): New dummy function.
>
> 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/builtins.cc | 2 +-
> gcc/collect2.cc | 7 +-
> gcc/common.opt | 8 +
> gcc/doc/gcov.texi | 36 +
> gcc/doc/invoke.texi | 19 +
> gcc/gcc.cc | 4 +-
> gcc/gcov-counter.def | 3 +
> gcc/gcov-dump.cc | 24 +
> gcc/gcov-io.h | 3 +
> gcc/gcov.cc | 200 +++-
> gcc/ipa-inline.cc | 2 +-
> gcc/ipa-split.cc | 3 +-
> gcc/passes.cc | 3 +-
> gcc/profile.cc | 84 +-
> gcc/testsuite/g++.dg/gcov/gcov-18.C | 234 +++++
> gcc/testsuite/gcc.misc-tests/gcov-19.c | 1250 ++++++++++++++++++++++++
> gcc/testsuite/gcc.misc-tests/gcov-20.c | 22 +
> gcc/testsuite/gcc.misc-tests/gcov-21.c | 16 +
> gcc/testsuite/lib/gcov.exp | 191 +++-
> gcc/tree-profile.cc | 1050 +++++++++++++++++++-
> libgcc/libgcov-merge.c | 5 +
> 21 files changed, 3138 insertions(+), 28 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
>
> diff --git a/gcc/builtins.cc b/gcc/builtins.cc
> index 5f319b28030..972ae7e2040 100644
> --- a/gcc/builtins.cc
> +++ b/gcc/builtins.cc
> @@ -5884,7 +5884,7 @@ 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 && !profile_condition_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 d81c7f28f16..0cd8bf4a3a3 100644
> --- a/gcc/collect2.cc
> +++ b/gcc/collect2.cc
> @@ -1032,9 +1032,9 @@ 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-profile-conditions -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);
> @@ -1230,6 +1230,7 @@ main (int argc, char **argv)
> }
> obstack_free (&temporary_obstack, temporary_firstobj);
> *c_ptr++ = "-fno-profile-arcs";
> + *c_ptr++ = "-fno-profile-conditions";
> *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 bce3e514f65..5d0682e283a 100644
> --- a/gcc/common.opt
> +++ b/gcc/common.opt
> @@ -859,6 +859,10 @@ 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 coverage gives up.
> +
> Wmissing-profile
> Common Var(warn_missing_profile) Init(1) Warning
> Warn in case profiles in -fprofile-use do not exist.
> @@ -2318,6 +2322,10 @@ fprofile-arcs
> Common Var(profile_arc_flag)
> Insert arc-based program profiling code.
>
> +fprofile-conditions
> +Common Var(profile_condition_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 a1f7d26e610..7f2c0d00d94 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 +170,13 @@ 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).
> +
> @item -d
> @itemx --display-progress
> Display the progress on the standard output.
> @@ -293,6 +301,7 @@ Each @var{line} has the following form:
> @{
> "branches": ["$branch"],
> "count": 2,
> + "conditions": ["$condition"],
> "line_number": 15,
> "unexecuted_block": false,
> "function_name": "foo",
> @@ -341,6 +350,33 @@ Fields of the @var{branch} element have following semantics:
> @var{throw}: true when the branch is an exceptional branch
> @end itemize
>
> +Each @var{condition} element have the following semantics:
> +
> +@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 conditions in this expression
> +
> +@item
> +@var{covered}: number of covered conditions 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 a9ecc4426a4..62d48df369d 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -614,6 +614,7 @@ Objective-C and Objective-C++ Dialects}.
> @item Program Instrumentation Options
> @xref{Instrumentation Options,,Program Instrumentation Options}.
> @gccoptlist{-p -pg -fprofile-arcs --coverage -ftest-coverage @gol
> +-fprofile-conditions @gol
> -fprofile-abs-path @gol
> -fprofile-dir=@var{path} -fprofile-generate -fprofile-generate=@var{path} @gol
> -fprofile-info-section -fprofile-info-section=@var{name} @gol
> @@ -6140,6 +6141,13 @@ error. @option{-Wno-coverage-invalid-line-number} can be used to disable the
> warning or @option{-Wno-error=coverage-invalid-line-number} can be used to
> disable the error.
>
> +@item -Wno-coverage-too-many-conditions
> +@opindex Wno-coverage-too-many-conditions
> +@opindex Wcoverage-too-many-conditions
> +Warn in case a condition 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.
> +
> @item -Wno-cpp @r{(C, Objective-C, C++, Objective-C++ and Fortran only)}
> @opindex Wno-cpp
> @opindex Wcpp
> @@ -15839,6 +15847,13 @@ E.g. @code{gcc a.c b.c -o binary} would generate @file{binary-a.gcda} and
>
> @xref{Cross-profiling}.
>
> +@item -fprofile-conditions
> +@opindex fprofile-conditions
> +Add code so that program conditions are instrumented. During execution the
> +program records what terms in a conditional contributes to a decision. The
> +data may be used to verify that all terms in a booleans are tested and have an
> +effect on the outcome of a condition.
> +
> @cindex @command{gcov}
> @item --coverage
> @opindex coverage
> @@ -15899,6 +15914,10 @@ 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{-fprofile-conditions}, for each conditional in your program GCC
> +creates a bitset and records the boolean values that have an independent effect
> +on the outcome of that expression.
> +
> @need 2000
> @item -ftest-coverage
> @opindex ftest-coverage
> diff --git a/gcc/gcc.cc b/gcc/gcc.cc
> index afb23cd07b0..601e48377de 100644
> --- a/gcc/gcc.cc
> +++ b/gcc/gcc.cc
> @@ -1145,7 +1145,7 @@ proper position among the other output files. */
> %:include(libgomp.spec)%(link_gomp)}\
> %{fgnu-tm:%:include(libitm.spec)%(link_itm)}\
> %(mflib) " STACK_SPLIT_SPEC "\
> - %{fprofile-arcs|fprofile-generate*|coverage:-lgcov} " SANITIZER_SPEC " \
> + %{fprofile-arcs|fprofile-conditions|fprofile-generate*|coverage:-lgcov} " SANITIZER_SPEC " \
> %{!nostdlib:%{!r:%{!nodefaultlibs:%(link_ssp) %(link_gcc_c_sequence)}}}\
> %{!nostdlib:%{!r:%{!nostartfiles:%E}}} %{T*} \n%(post_link) }}}}}}"
> #endif
> @@ -1262,7 +1262,7 @@ 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|fprofile-conditions|fprofile-generate*|coverage:\
> %{!fprofile-update=single:\
> %{pthread:-fprofile-update=prefer-atomic}}}";
>
> diff --git a/gcc/gcov-counter.def b/gcc/gcov-counter.def
> index 6d2182bd3db..96563a59a45 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 03023bfb226..6dc1df6e3e1 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,
> }
> }
>
> +static void
> +tag_conditions (const char *filename ATTRIBUTE_UNUSED,
> + unsigned tag ATTRIBUTE_UNUSED, int length ATTRIBUTE_UNUSED,
> + unsigned depth)
> +{
> + unsigned n_conditions = GCOV_TAG_CONDS_NUM (length);
> +
> + printf (" %u conditionals", 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 e91cd736556..a9b52cc6abc 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 9cf1071166f..bc2932e7890 100644
> --- a/gcc/gcov.cc
> +++ b/gcc/gcov.cc
> @@ -79,6 +79,7 @@ using namespace std;
> class function_info;
> class block_info;
> class source_info;
> +class condition_info;
>
> /* Describes an arc between two basic blocks. */
>
> @@ -132,6 +133,28 @@ public:
> vector<unsigned> lines;
> };
>
> +class condition_info
> +{
> +public:
> + condition_info ();
> +
> + int popcount () const;
> +
> + gcov_type_unsigned truev;
> + gcov_type_unsigned falsev;
> +
> + unsigned n_terms;
> +};
> +
> +condition_info::condition_info (): truev (0), falsev (0), n_terms (0)
> +{
> +}
> +
> +int condition_info::popcount () const
> +{
> + return __builtin_popcountll (truev) + __builtin_popcountll (falsev);
> +}
> +
> /* Describes a basic block. Contains lists of arcs to successor and
> predecessor blocks. */
>
> @@ -165,6 +188,8 @@ public:
> /* Block is a landing pad for longjmp or throw. */
> unsigned is_nonlocal_return : 1;
>
> + condition_info conditions;
> +
> vector<block_location_info> locations;
>
> struct
> @@ -275,6 +300,8 @@ public:
> vector<block_info> blocks;
> unsigned blocks_executed;
>
> + vector<condition_info*> conditions;
> +
> /* Raw arc coverage counts. */
> vector<gcov_type> counts;
>
> @@ -351,6 +378,9 @@ struct coverage_info
> int branches_executed;
> int branches_taken;
>
> + int conditions;
> + int conditions_covered;
> +
> int calls;
> int calls_executed;
>
> @@ -550,6 +580,10 @@ static int multiple_files = 0;
>
> static int flag_branches = 0;
>
> +/* Output conditions (modified condition/decision coverage) */
> +
> +static int flag_conditions = 0;
> +
> /* Show unconditional branches too. */
> static int flag_unconditional = 0;
>
> @@ -656,6 +690,7 @@ 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 *);
> @@ -664,6 +699,7 @@ 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 *);
> @@ -928,6 +964,7 @@ 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 condition/decision 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");
> @@ -980,6 +1017,7 @@ 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' },
> @@ -1008,7 +1046,7 @@ 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)
> @@ -1025,6 +1063,9 @@ 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. */
> @@ -1132,6 +1173,45 @@ 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);
> }
>
> @@ -1956,6 +2036,28 @@ 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 ();
> @@ -2086,11 +2188,26 @@ read_count_file (void)
> goto cleanup;
> }
> }
> - else if (tag == GCOV_TAG_FOR_COUNTER (GCOV_COUNTER_ARCS) && fn)
> + 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);
> if (length != GCOV_TAG_COUNTER_LENGTH (fn->counts.size ()))
> - goto mismatch;
> + goto mismatch;
>
> if (read_length > 0)
> for (ix = 0; ix != fn->counts.size (); ix++)
> @@ -2430,6 +2547,13 @@ add_branch_counts (coverage_info *coverage, const arc_info *arc)
> }
> }
>
> +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. */
>
> @@ -2533,6 +2657,18 @@ file_summary (const coverage_info *coverage)
> coverage->calls);
> else
> fnotice (stdout, "No calls\n");
> +
> + }
> +
> + if (flag_conditions)
> + {
> + if (coverage->conditions)
> + fnotice (stdout, "Decisions covered:%s of %d\n",
> + format_gcov (coverage->conditions_covered,
> + coverage->conditions, 2),
> + coverage->conditions);
> + else
> + fnotice (stdout, "No decisions\n");
> }
> }
>
> @@ -2767,6 +2903,12 @@ 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
> @@ -2868,6 +3010,33 @@ accumulate_line_counts (source_info *src)
> }
> }
>
> +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. */
>
> @@ -3078,16 +3247,29 @@ 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/ipa-inline.cc b/gcc/ipa-inline.cc
> index 14969198cde..3e37305843e 100644
> --- a/gcc/ipa-inline.cc
> +++ b/gcc/ipa-inline.cc
> @@ -646,7 +646,7 @@ can_early_inline_edge_p (struct cgraph_edge *e)
> " edge not inlinable: not in SSA form\n");
> return false;
> }
> - else if (profile_arc_flag
> + else if ((profile_arc_flag || profile_condition_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 16734617d03..07d2b17ab12 100644
> --- a/gcc/ipa-split.cc
> +++ b/gcc/ipa-split.cc
> @@ -1929,7 +1929,8 @@ 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
> + && !profile_condition_flag);
> }
>
> } // anon namespace
> diff --git a/gcc/passes.cc b/gcc/passes.cc
> index 78a07f8691a..3457ad1c5b3 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 || profile_condition_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 96121d60711..f7f6d1f7197 100644
> --- a/gcc/profile.cc
> +++ b/gcc/profile.cc
> @@ -66,9 +66,19 @@ along with GCC; see the file COPYING3. If not see
> #include "cfgloop.h"
> #include "sreal.h"
> #include "file-prefix-map.h"
> +#include "stringpool.h"
>
> #include "profile.h"
>
> +struct condcov;
> +struct condcov *find_conditions (struct function*);
> +unsigned cov_length (const struct condcov*);
> +array_slice<basic_block> cov_blocks (struct condcov*, unsigned);
> +array_slice<gcov_type_unsigned > cov_masks (struct condcov*, unsigned);
> +void cov_free (struct condcov*);
> +int instrument_decisions (array_slice<basic_block>, unsigned, tree*,
> + 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 +110,7 @@ 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 +1166,12 @@ 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 +1190,7 @@ 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 +1415,18 @@ 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));
> @@ -1512,29 +1538,74 @@ branch_prob (bool thunk)
>
> remove_fake_edges ();
>
> + if (profile_condition_flag || profile_arc_flag)
> + gimple_init_gcov_profiler ();
> +
> + if (profile_condition_flag)
> + {
> + struct condcov *cov = find_conditions (cfun);
> + gcc_assert (cov);
> + const unsigned nconds = cov_length (cov);
> + total_num_conds += nconds;
> +
> + if (coverage_counter_alloc (GCOV_COUNTER_CONDS, 2 * nconds))
> + {
> + /* Add two extra variables to the function for the local
> + accumulators, which are zero'd on the entry of a new conditional.
> + The local accumulators are shared between decisions in order to
> + use less stack space. */
> + tree accu[2] = {
> + build_decl (UNKNOWN_LOCATION, VAR_DECL,
> + get_identifier ("__accu_t"), get_gcov_type ()),
> + build_decl (UNKNOWN_LOCATION, VAR_DECL,
> + get_identifier ("__accu_f"), get_gcov_type ()),
> + };
> +
> + gcov_position_t offset {};
> + if (output_to_file)
> + offset = gcov_write_tag (GCOV_TAG_CONDS);
> +
> + for (unsigned i = 0; i < nconds; ++i)
> + {
> + array_slice<basic_block> expr = cov_blocks (cov, i);
> + array_slice<gcov_type_unsigned> masks = cov_masks (cov, i);
> + gcc_assert (expr.is_valid ());
> + gcc_assert (masks.is_valid ());
> +
> + int terms = instrument_decisions (expr, i, accu, masks.begin ());
> + 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))
> @@ -1664,6 +1735,7 @@ 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;
> }
> @@ -1703,5 +1775,7 @@ 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..310ed5297c0
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/gcov/gcov-18.C
> @@ -0,0 +1,234 @@
> +/* { dg-options "--coverage -fprofile-conditions -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;
> +}
> +
> +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);
> +
> +}
> +
> +/* { 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..1adff7c76f4
> --- /dev/null
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-19.c
> @@ -0,0 +1,1250 @@
> +/* { dg-options "-fprofile-conditions -ftest-coverage" } */
> +/* { dg-do run { target native } } */
> +
> +/* some side effect to stop branches from being pruned */
> +int x = 0;
> +
> +/* || 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)
> +{
> + /* With no else this is interpreted as (a && (b || c)) */
> + if (a) /* conditions(3/6) true(2) false(1 2)*/
> + {
> + if (b || c)
> + x = a + b + c;
> + }
> +}
> +
> +void
> +mcdc004e (int a, int b, int c)
> +{
> + /* With the else, this is interpreted as 2 expressions */
> + if (a) /* conditions(2/2) */
> + {
> + if (b || c) /* conditions(1/4) true(1) false(0 1) */
> + x = a + b + c;
> + }
> + else
> + {
> + x = c;
> + }
> +}
> +
> +/* 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;
> +}
> +
> +/* 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(6/6) */
> + if (b)
> + if (c)
> + 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;
> + }
> +}
> +
> +/* 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:
> + /* Evaluates to if (a || b || c) x = 1 */
> + if (a) /* conditions(5/6) true(2) */
> + /* conditions(end) */
> + goto then;
> + else if (b)
> + goto then;
> + else if (c)
> + 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:
> + /* similar to if (a || b || c) x = 1 */
> + 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;
> +}
> +
> +/* 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;
> +}
> +
> +void
> +mcdc008d (int a, int b, int c, int d)
> +{
> + /* multi-term loop conditional */
> + 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--;
> +}
> +
> +/* 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 always (int x) { (void) x; return 1; }
> +
> +/* no-condition infinite loops */
> +void
> +mcdc010c (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 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
> + *
> + * But the expression was implemented wrong. 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;
> + }
> +}
> +
> +
> +/* check 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
> +noop () {}
> +
> +void
> +mcdc017b (int a, int b)
> +{
> + do
> + {
> + /*
> + * This call is important; it can add more nodes to the body in the
> + * CFG, which has 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) */
> + {
> + right = b > right ? a : right; /* conditions(2/2) */
> + }
> + } while (n-- > 0); /* conditions(2/2) */
> +}
> +
> +int id (int x) { return x; }
> +int inv (int x) { return !x; }
> +
> +/* 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) */
> + {
> + 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) */
> + 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) */
> +}
> +
> +void
> +mcdc020c (int a, int b)
> +{
> + x = a ? 0
> + : b ? 1 /* conditions(2/2) */
> + : 2; /* conditions(1/2) false(0) */
> + /* 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;
> +}
> +
> +/* 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;
> +}
> +
> +void
> +mcdc024a (int a, int b)
> +{
> + if (a && b) /* conditions(1/4) true(0 1) false(1) */
> + /* conditions(end) */
> + {
> +label1:
> + x = 1;
> + }
> + else
> + {
> + x = 2;
> + }
> +
> + if (a || b) /* conditions(2/4) true(0 1) */
> + /* conditions(end) */
> + {
> +label2:
> + x = 1;
> + }
> + else
> + {
> + x = 2;
> + }
> +}
> +
> +void
> +mcdc024b (int a, int b)
> +{
> +
> + if (a && b) /* conditions(1/4) true(0 1) false(1) */
> + /* conditions(end) */
> + {
> + x = 1;
> + }
> + else
> + {
> +label1:
> + x = 2;
> + }
> +
> + if (a || b) /* conditions(2/4) true(0 1) */
> + /* conditions(end) */
> + {
> + x = 1;
> + }
> + else
> + {
> +label2:
> + x = 2;
> + }
> +}
> +
> +void
> +mcdc024c (int a, int b)
> +{
> + if (a && b) /* conditions(1/4) true(0 1) false(1) */
> + /* conditions(end) */
> + {
> +label1:
> + x = 1;
> + }
> + else
> + {
> +label2:
> + x = 2;
> + }
> +
> + if (a || b) /* conditions(2/4) true(0 1) */
> + /* conditions(end) */
> + {
> +label3:
> + x = 1;
> + }
> + else
> + {
> +label4:
> + x = 2;
> + }
> +}
> +
> +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);
> +
> + mcdc005a (1, 0, 1);
> +
> + mcdc005b (1, 1, 0, 0);
> + mcdc005b (1, 0, 0, 0);
> +
> + mcdc005c (0, 1, 1, 0);
> +
> + mcdc005d (1, 0, 0, 0);
> +
> + 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);
> +
> + 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);
> +
> + 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);
> +
> + mcdc010a (0, 0);
> + mcdc010a (0, 9);
> + mcdc010a (2, 1);
> +
> + mcdc010b ();
> +
> + mcdc010c (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);
> +
> + 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);
> +
> + mcdc021d (1, 0, 1, 0);
> +
> + mcdc022a (0, 0);
> +
> + mcdc022b (0);
> + mcdc022b (1);
> +
> + mcdc022c (0);
> + mcdc022c (1);
> +
> + mcdc022d (1);
> +
> + 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, 0);
> + mcdc024b (0, 0);
> + mcdc024c (0, 0);
> +}
> +
> +/* { 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..847dae495db
> --- /dev/null
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-20.c
> @@ -0,0 +1,22 @@
> +/* { dg-options "-fprofile-conditions -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..978be3276a2
> --- /dev/null
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-21.c
> @@ -0,0 +1,16 @@
> +/* { dg-options "-fprofile-conditions" } */
> +
> +/* 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/lib/gcov.exp b/gcc/testsuite/lib/gcov.exp
> index 9d5b2cdb86b..69168d67d03 100644
> --- a/gcc/testsuite/lib/gcov.exp
> +++ b/gcc/testsuite/lib/gcov.exp
> @@ -174,6 +174,184 @@ 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.
> +#
> +# 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 n 0
> + set keywords {"end" "suppress"}
> + while {[gets $fd line] >= 0} {
> + regexp "^\[^:\]+: *(\[0-9\]+):" "$line" all n
> + set prefix "$testname line $n"
> +
> + 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 e] {
> + # *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.
> + 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
> + }
> +
> + set suppress 0
> + set destructor 0
> + set should ""
> + set shouldt ""
> + set shouldf ""
> + set shouldall ""
> + set newt ""
> + set newf ""
> +
> + if [regexp {destructor\(\)} "$line"] {
> + set destructor 1
> + }
> +
> + if [regexp {(\d+)/(\d+)} "$e" all i k] {
> + regexp {true\(([0-9 ]+)\)} "$line" all newt
> + regexp {false\(([0-9 ]+)\)} "$line" all newf
> +
> + # 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 $newf]]
> + set nexpected [expr {$k - $i}]
> + if {$nterms != $nexpected} {
> + fail "$prefix: expected $nexpected uncovered terms; got $nterms"
> + set ok 0
> + }
> + set shouldall $e
> + set shouldt $newt
> + set shouldf $newf
> + } elseif {$e == "end"} {
> + # no-op - state has 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 $i]
> + } else {
> + fail "$testname line $n: 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 == "" && $destructor == 1} {
> + set suppress 1
> + continue
> + }
> +
> + if {$cond == $shouldall} {
> + set shouldall ""
> + } else {
> + fail "$testname line $n: unexpected summary $cond"
> + set ok 0
> + }
> + }
> +
> + if {$ok != 1} {
> + incr failed
> + }
> + }
> + close $fd
> + return $failed
> +}
> +
> #
> # verify-calls -- check that call return percentages are as expected
> #
> @@ -321,6 +499,7 @@ 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 +510,13 @@ 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 +586,11 @@ 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 +605,12 @@ 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-profile.cc b/gcc/tree-profile.cc
> index 2beb49241f2..0b537d64d97 100644
> --- a/gcc/tree-profile.cc
> +++ b/gcc/tree-profile.cc
> @@ -58,6 +58,8 @@ 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"
> +#include "cfgloop.h"
>
> static GTY(()) tree gcov_type_node;
> static GTY(()) tree tree_interval_profiler_fn;
> @@ -73,6 +75,1048 @@ static GTY(()) tree ic_tuple_var;
> static GTY(()) tree ic_tuple_counters_field;
> static GTY(()) tree ic_tuple_callee_field;
>
> +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
> +{
> + /* Bitmap of the processed blocks. Bit n set means basic_block->index has
> + been processed either explicitly or as a part of an expression. */
> + auto_sbitmap marks;
> +
> + /* 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, 32> blocks;
> +
> + /* Map from basic_block->index to an ordering so that for a single
> + expression (a || b && c) => index_map[a] < index_map[b] < index_map[c].
> + The values do not have to be consecutive and can be interleaved by
> + values from other expressions, so comparisons only make sense for blocks
> + that belong to the same expression. */
> + auto_vec<int, 64> index_map;
> +
> + /* 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) : marks (size),
> + G1 (size), G2 (size), G3 (size)
> + {
> + bitmap_clear (marks);
> + }
> +
> + /* Mark a node as processed so nodes are not processed twice for example in
> + loops, gotos. */
> + void mark (const basic_block b) noexcept (true)
> + {
> + gcc_assert (!bitmap_bit_p (marks, b->index));
> + bitmap_set_bit (marks, b->index);
> + }
> +
> + /* Mark nodes as processed so they are not processed twice. */
> + void mark (const vec<basic_block>& bs) noexcept (true)
> + {
> + for (const basic_block b : bs)
> + mark (b);
> + }
> +
> + /* Check if all nodes are marked. A successful run should visit & mark
> + every reachable node exactly once. */
> + bool all_marked (const vec<basic_block>& reachable) const noexcept (true)
> + {
> + for (const basic_block b : reachable)
> + if (!bitmap_bit_p (marks, b->index))
> + return false;
> + return true;
> + }
> +};
> +
> +/* 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 (sizeof (gcov_type_unsigned) * BITS_PER_UNIT)
> +#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 cmp_index_map (a, b, ...) < 0. The result is undefined if lhs, rhs
> + belong to different expressions. */
> +int
> +cmp_index_map (const void *lhs, const void *rhs, void *index_map)
> +{
> + const_basic_block l = *(const basic_block*) lhs;
> + const_basic_block r = *(const basic_block*) rhs;
> + const vec<int>* im = (const vec<int>*) index_map;
> + 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;
> +}
> +
> +/* Returns true if this is a conditional node, i.e. it has outgoing true and
> + false edges. */
> +bool
> +block_conditional_p (const basic_block b)
> +{
> + unsigned t = 0;
> + unsigned f = 0;
> + for (edge e : b->succs)
> + {
> + t |= (e->flags & EDGE_TRUE_VALUE);
> + f |= (e->flags & EDGE_FALSE_VALUE);
> + }
> + return t && f;
> +}
> +
> +/* Check if the edge is a conditional. */
> +bool
> +edge_conditional_p (const edge e)
> +{
> + return e->flags & EDGE_CONDITION;
> +}
> +
> +/* 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 [1], it should be considered a
> + single-successor.
> +
> + [1] if this is not possible, these functions can be removed and replaced by
> + their basic-block.h cousins. */
> +bool
> +single (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)
> +{
> + for (edge e : edges)
> + {
> + if (e->flags & EDGE_COMPLEX)
> + continue;
> + return e;
> + }
> + return NULL;
> +}
> +
> +/* Sometimes, for example with function calls 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
> +
> + contract_edge ignores the series of intermediate nodes and makes a virtual
> + edge A -> C without having to construct a new simplified CFG explicitly. It
> + gets more complicated as non-conditional edges is how the body of the
> + then/else blocks are separated from the boolean expression, so only edges
> + that are inserted because of function calls in the expression itself must be
> + merged.
> +
> + Only chains of single-exit single-entry nodes that end with a condition
> + should be contracted. */
> +edge
> +contract_edge (edge e)
> +{
> + edge source = e;
> + while (true)
> + {
> + basic_block dest = e->dest;
> + if (!single (dest->preds))
> + return source;
> + if (e->flags & EDGE_DFS_BACK)
> + return source;
> + if (block_conditional_p (dest))
> + return e;
> +
> + e = single_edge (dest->succs);
> + if (!e)
> + return source;
> + }
> +}
> +
> +/* This is the predecessor dual of contract_edge; it collapses the predecessor
> + blocks between two operands in a boolean expression. */
> +edge
> +contract_edge_up (edge e)
> +{
> + while (true)
> + {
> + basic_block src = e->src;
> + if (edge_conditional_p (e))
> + return e;
> + if (!single (src->preds))
> + return e;
> + e = single_edge (src->preds);
> + }
> +}
> +
> +/* "Undo" an edge split. Sometimes the sink of a boolean expression will be
> + split into multiple blocks to accurately track line coverage, for example
> + when there is a goto-label at the top of the then/else block:
> +
> + if (a && b)
> + {
> + l1:
> + ...
> + }
> + else
> + {
> + l2:
> + ...
> + }
> +
> + and the corresponding CFG where a1 and b1 are created in edge splits to the
> + same destination (F):
> +
> + a
> + |\
> + | a1
> + b \
> + |\ |
> + | b1|
> + | \|
> + T F
> +
> + This function recognizes this shape and returns the "merges" the split
> + outcome block by returning their common successor. In all other cases it is
> + the identity function.
> +*/
> +basic_block
> +merge_split_outcome (basic_block b)
> +{
> + if (!single (b->succs))
> + return b;
> + if (!single (b->preds))
> + return b;
> +
> + const unsigned flag = single_edge (b->preds)->flags & EDGE_CONDITION;
> + if (!flag)
> + return b;
> +
> + edge e = single_edge (b->succs);
> + for (edge pred : e->dest->preds)
> + {
> + if (!single (pred->src->preds))
> + return b;
> + if (!(single_edge (pred->src->preds)->flags & flag))
> + return b;
> + }
> + return e->dest;
> +}
> +
> +
> +/* Find the set {ancestors(p) intersect G} where ancestors is the recursive set
> + of predecessors for p. Limiting to the ancestors that are also in G (see
> + cond_reachable_from) and by q is an optimization as ancestors outside G have
> + no effect when isolating expressions.
> +
> + dfs_enumerate_from () does not work as the filter function needs edge
> + information and dfs_enumerate_from () only considers blocks. */
> +void
> +ancestors_of (basic_block p, basic_block q, const sbitmap G, sbitmap ancestors)
> +{
> + if (!bitmap_bit_p (G, p->index))
> + return;
> +
> + bitmap_set_bit (ancestors, p->index);
> + bitmap_set_bit (ancestors, q->index);
> + if (p == q)
> + return;
> +
> + auto_vec<basic_block, 16> stack;
> + stack.safe_push (p);
> +
> + while (!stack.is_empty())
> + {
> + basic_block b = stack.pop ();
> + if (single (b->preds))
> + {
> + edge e = single_edge (b->preds);
> + e = contract_edge_up (e);
> + b = e->dest;
> + }
> +
> + for (edge e : b->preds)
> + {
> + basic_block src = e->src;
> + if (bitmap_bit_p (ancestors, e->src->index))
> + continue;
> + if (!bitmap_bit_p (G, e->src->index))
> + continue;
> + bitmap_set_bit (ancestors, src->index);
> + stack.safe_push (src);
> + }
> + }
> +}
> +
> +/* 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 = merge_split_outcome (e->dest);
> + if (e->flags & EDGE_FALSE_VALUE)
> + c.f = merge_split_outcome (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;
> +}
> +
> +/* Compute the masking vector.
> +
> + 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 in the CFG 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.
> +
> + 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
> + destination. The top is always the node corresponding to the left-most
> + operand of the two it holds that index_map[top] < index_map[bot].
> +
> + Now consider (a && b) || (c && d) and its masking vectors:
> +
> + 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 nodes in an expression have outgoing edges to either the outcome or some
> + other node in the expression. The "bot" node is also the last term in a
> + masked subexpression, so the problem becomes finding the subgraph where all
> + paths end up in the successors to bot.
> +
> + 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 vector is represented as two bitfields per term in the
> + expression with the index corresponding to the term in the source
> + expression. a || b && c becomes the term vector [a b c] and the masking
> + vectors [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. */
> +void
> +masking_vectors (conds_ctx& ctx, array_slice<basic_block> blocks,
> + array_slice<gcov_type_unsigned> masks)
> +{
> + gcc_assert (blocks.is_valid ());
> + gcc_assert (!blocks.empty ());
> + gcc_assert (masks.is_valid ());
> +
> + sbitmap marks = ctx.G1;
> + sbitmap expr = ctx.G2;
> + vec<basic_block>& queue = ctx.B1;
> + vec<basic_block>& body = ctx.B2;
> + const vec<int>& index_map = ctx.index_map;
> + bitmap_clear (expr);
> +
> + for (const basic_block b : blocks)
> + bitmap_set_bit (expr, b->index);
> +
> + /* Set up for the iteration - include two outcome nodes in the traversal and
> + ignore the leading term since it cannot mask anything. The algorithm is
> + not sensitive to the traversal order. */
> + body.truncate (0);
> + body.reserve (blocks.size () + 2);
> + for (const basic_block b : blocks)
> + body.quick_push (b);
> +
> + outcomes out = conditional_succs (blocks.back ());
> + body.quick_push (out.t);
> + body.quick_push (out.f);
> + body[0] = body.pop ();
> +
> + for (const basic_block b : body)
> + {
> + for (edge e1 : b->preds)
> + for (edge e2 : b->preds)
> + {
> + const basic_block top = e1->src;
> + const basic_block bot = e2->src;
> + const unsigned cond = e1->flags & e2->flags & (EDGE_CONDITION);
> +
> + if (!cond)
> + continue;
> + if (e1 == e2)
> + continue;
> + if (!bitmap_bit_p (expr, top->index))
> + continue;
> + if (!bitmap_bit_p (expr, bot->index))
> + continue;
> + if (index_map[top->index] > index_map[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, blocks) + condition_index (cond);
> + 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, blocks);
> + gcc_assert (index != -1);
> + masks[m] |= gcov_type_unsigned (1) << index;
> + bitmap_set_bit (marks, q->index);
> +
> + for (edge e : q->preds)
> + {
> + e = contract_edge_up (e);
> + if (!edge_conditional_p (e))
> + continue;
> + if (e->flags & EDGE_DFS_BACK)
> + continue;
> + if (bitmap_bit_p (marks, e->src->index))
> + continue;
> + if (!bitmap_bit_p (expr, e->src->index))
> + continue;
> + queue.safe_push (e->src);
> + }
> + }
> + }
> + }
> +}
> +
> +/* Find the nodes reachable from p by following only (possibly contracted)
> + condition edges dominated by p and ignore DFS back edges. From a high level
> + this is partitioning the CFG into subgraphs by removing all non-condition
> + edges and selecting a single connected subgraph. This creates a cut C = (G,
> + G') where G is the returned explicitly by this function.
> +
> + It is assumed that all paths from p go through q (q post-dominates p). p
> + must always be the first term in an expression and a condition node.
> +
> + If |G| = 1 then this is a single term expression. If |G| > 1 then either
> + this is a multi-term expression or the first block in the then/else block is
> + a conditional expression as well.
> +
> + Only nodes dominated by p is added - under optimization some blocks may be
> + merged and multiple independent conditions may share the same outcome
> + (making successors misidentified as a right operands), but true right-hand
> + operands are always dominated by the first term.
> +
> + The function outputs both a bitmap and a vector as both are useful to the
> + caller. */
> +void
> +cond_reachable_from (basic_block p, basic_block q, sbitmap expr,
> + vec<basic_block>& out)
> +{
> + out.safe_push (p);
> + bitmap_set_bit (expr, p->index);
> + for (unsigned pos = 0; pos < out.length (); pos++)
> + {
> + for (edge e : out[pos]->succs)
> + {
> + basic_block dest = contract_edge (e)->dest;
> + if (dest == q)
> + continue;
> + if (!dominated_by_p (CDI_DOMINATORS, dest, p))
> + continue;
> + if (!block_conditional_p (dest))
> + continue;
> + if (bitmap_bit_p (expr, dest->index))
> + continue;
> + if (e->flags & EDGE_DFS_BACK)
> + continue;
> +
> + bitmap_set_bit (expr, dest->index);
> + out.safe_push (dest);
> + }
> + }
> +}
> +
> +/* Find the neighborhood of the graph G = [blocks, blocks+n), the
> + successors of nodes in G that are not also in G. In the cut C = (G, G')
> + these are the nodes in G' with incoming edges that cross the span. */
> +void
> +neighborhood (const vec<basic_block>& blocks, sbitmap G, vec<basic_block>& out)
> +{
> + for (const basic_block b : blocks)
> + {
> + for (edge e : b->succs)
> + {
> + basic_block dest = contract_edge (e)->dest;
> + if (bitmap_bit_p (G, dest->index))
> + continue;
> + if (!out.contains (dest))
> + out.safe_push (dest);
> + }
> + }
> +
> + /* Fix the neighborhood by correcting edge splits to the outcome nodes. */
> + for (unsigned i = 0; i != out.length (); i++)
> + {
> + basic_block prev = out[i];
> + basic_block next = merge_split_outcome (prev);
> + if (next->index != prev->index)
> + {
> + bitmap_set_bit (G, prev->index);
> + out[i] = next;
> + }
> + }
> +}
> +
> +/* Find and isolate the expression starting at p.
> +
> + Make a cut C = (G, G') following only condition edges. G is a superset of
> + the expression B, but the walk may include expressions from the then/else
> + blocks if they start with conditions. Only the subgraph B is the ancestor
> + of *both* the then/else outcome, which means B is the intersection of the
> + ancestors of the nodes in the neighborhood N(G). */
> +void
> +isolate_expression (conds_ctx &ctx, basic_block p, vec<basic_block>& out)
> +{
> + sbitmap expr = ctx.G1;
> + sbitmap reachable = ctx.G2;
> + sbitmap ancestors = ctx.G3;
> + bitmap_clear (expr);
> + bitmap_clear (reachable);
> +
> + vec<basic_block>& G = ctx.B1;
> + vec<basic_block>& NG = ctx.B2;
> + G.truncate (0);
> + NG.truncate (0);
> +
> + basic_block post = get_immediate_dominator (CDI_POST_DOMINATORS, p);
> + cond_reachable_from (p, post, reachable, G);
> + if (G.length () == 1)
> + {
> + out.safe_push (p);
> + return;
> + }
> +
> + neighborhood (G, reachable, NG);
> + bitmap_copy (expr, reachable);
> +
> + for (const basic_block neighbor : NG)
> + {
> + bitmap_clear (ancestors);
> + for (edge e : neighbor->preds)
> + ancestors_of (e->src, p, reachable, ancestors);
> + bitmap_and (expr, expr, ancestors);
> + }
> +
> + for (const basic_block b : G)
> + if (bitmap_bit_p (expr, b->index))
> + out.safe_push (b);
> + out.sort (cmp_index_map, &ctx.index_map);
> +}
> +
> +/* Emit lhs = op1 <op> op2 on edges. This emits non-atomic instructions and
> + should only be used on the local accumulators. */
> +void
> +emit_bitwise_op (edge e, tree lhs, tree op1, tree_code op, tree op2)
> +{
> + tree tmp;
> + gassign *read;
> + gassign *bitw;
> + gimple *write;
> +
> + tmp = make_temp_ssa_name (gcov_type_node, NULL, "__conditions_tmp");
> + read = gimple_build_assign (tmp, op1);
> + tmp = make_temp_ssa_name (gcov_type_node, NULL, "__conditions_tmp");
> + bitw = gimple_build_assign (tmp, op, gimple_assign_lhs (read), op2);
> + write = gimple_build_assign (lhs, gimple_assign_lhs (bitw));
> +
> + gsi_insert_on_edge (e, read);
> + gsi_insert_on_edge (e, bitw);
> + gsi_insert_on_edge (e, write);
> +}
> +
> +/* Visitor for make_index_map. */
> +void
> +make_index_map_visit (basic_block b, vec<basic_block>& L, vec<int>& marks)
> +{
> + if (marks[b->index])
> + return;
> +
> + for (edge e : b->succs)
> + if (!(e->flags & EDGE_DFS_BACK))
> + make_index_map_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).
> +
> + It is important to select unvisited nodes in DFS order to ensure the
> + roots/leading terms of boolean expressions are visited first (the other
> + terms being covered by the recursive step), but the visiting order of
> + individual boolean expressions carries no significance.
> +
> + For the expression (a || (b && c) || d) the blocks should be [a b c d]. */
> +void
> +make_index_map (const vec<basic_block>& blocks, int max_index,
> + vec<basic_block>& L, vec<int>& index_map)
> +{
> + L.truncate (0);
> + L.reserve (max_index);
> +
> + /* Use of the output map as a temporary for tracking visited status. */
> + index_map.truncate (0);
> + index_map.safe_grow_cleared (max_index);
> + for (const basic_block b : blocks)
> + make_index_map_visit (b, L, index_map);
> +
> + /* 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 < index_map.length (); i++)
> + index_map[i] = -1;
> +
> + gcc_assert (blocks.length () == L.length ());
> + L.reverse ();
> + const unsigned nblocks = L.length ();
> + for (unsigned i = 0; i < nblocks; i++)
> + {
> + gcc_assert (L[i]->index != -1);
> + index_map[L[i]->index] = int (i);
> + }
> +}
> +
> +/* Walk the CFG and collect conditionals.
> +
> + 1. Collect a candidate set G by walking from the root following all
> + (contracted) condition edges.
> + 2. This creates a cut C = (G, G'); find the neighborhood N(G).
> + 3. For every node in N(G), follow the edges across the cut and collect all
> + ancestors (that are also in G).
> + 4. The intersection of all these ancestor sets is the boolean expression B
> + that starts in root.
> +
> + Walking is not guaranteed to find nodes in the order of the expression, it
> + might find (a || b) && c as [a c b], so the result must be sorted by the
> + index map. */
> +const vec<basic_block>&
> +collect_conditions (conds_ctx& ctx, const basic_block block)
> +{
> + vec<basic_block>& blocks = ctx.blocks;
> + blocks.truncate (0);
> +
> + if (bitmap_bit_p (ctx.marks, block->index))
> + return blocks;
> +
> + if (!block_conditional_p (block))
> + {
> + ctx.mark (block);
> + return blocks;
> + }
> +
> + isolate_expression (ctx, block, blocks);
> + ctx.mark (blocks);
> +
> + if (blocks.length () > CONDITIONS_MAX_TERMS)
> + {
> + location_t loc = gimple_location (gsi_stmt (gsi_last_bb (block)));
> + warning_at (loc, OPT_Wcoverage_too_many_conditions,
> + "Too many conditions (found %u); giving up coverage",
> + blocks.length ());
> + blocks.truncate (0);
> + }
> + return blocks;
> +}
> +
> +/* Used for dfs_enumerate_from () to include all reachable nodes. */
> +bool
> +yes (const_basic_block, const void *)
> +{
> + return true;
> +}
> +
> +}
> +
> +struct condcov {
> + explicit condcov (unsigned nblocks) noexcept (true) : ctx (nblocks) {}
> + auto_vec<int, 128> m_index;
> + auto_vec<basic_block, 256> m_blocks;
> + auto_vec<gcov_type_unsigned, 512> m_masks;
> + conds_ctx ctx;
> +};
> +
> +unsigned
> +cov_length (const struct condcov* cov)
> +{
> + if (cov->m_index.is_empty ())
> + return 0;
> + return cov->m_index.length () - 1;
> +}
> +
> +array_slice<basic_block>
> +cov_blocks (struct condcov* cov, unsigned 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);
> +}
> +
> +array_slice<gcov_type_unsigned>
> +cov_masks (struct condcov* cov, unsigned n)
> +{
> + if (n >= cov->m_index.length ())
> + return array_slice<gcov_type_unsigned>::invalid ();
> +
> + gcov_type_unsigned *begin = cov->m_masks.begin () + 2*cov->m_index[n];
> + gcov_type_unsigned *end = cov->m_masks.begin () + 2*cov->m_index[n + 1];
> + return array_slice<gcov_type_unsigned> (begin, end - begin);
> +}
> +
> +void
> +cov_free (struct condcov* cov)
> +{
> + delete cov;
> +}
> +
> +/* Condition coverage (MC/DC)
> +
> + Algorithm
> + ---------
> + 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 analyses the control flow graph to analyze
> + expressions and compute masking vectors, but is inspired by their marking
> + functions for recording outcomes. The individual phases are described in
> + more detail closer to the implementation.
> +
> + The CFG is traversed in DFS order. It is important that the first basic
> + block in an expression is the first one visited, but the order of
> + independent expressions does not matter. When the function terminates,
> + every node in the dfs should have been processed and marked exactly once.
> + If there are unreachable nodes they are ignored and not instrumented.
> +
> + The CFG is broken up into segments between dominators. This isn't strictly
> + necessary, but since boolean expressions cannot cross dominators it makes
> + for a nice way to introduce limits to searches.
> +
> + 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].
> +
> + 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.
> + */
> +struct condcov*
> +find_conditions (struct function *fn)
> +{
> + record_loop_exits ();
> + 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);
> + condcov *cov = new condcov (nblocks);
> + conds_ctx& ctx = cov->ctx;
> +
> + auto_vec<basic_block, 16> dfs;
> + dfs.safe_grow (nblocks);
> + const basic_block entry = ENTRY_BLOCK_PTR_FOR_FN (fn);
> + const basic_block exit = ENTRY_BLOCK_PTR_FOR_FN (fn);
> + int n = dfs_enumerate_from (entry, 0, yes, dfs.address (), nblocks, exit);
> + dfs.truncate (n);
> + make_index_map (dfs, nblocks, ctx.B1, ctx.index_map);
> +
> + /* Visit all reachable nodes and collect conditions. DFS 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 (const basic_block b : dfs)
> + {
> + const vec<basic_block>& expr = collect_conditions (ctx, b);
> + if (!expr.is_empty ())
> + {
> + cov->m_blocks.safe_splice (expr);
> + cov->m_index.safe_push (cov->m_blocks.length ());
> + }
> + }
> + gcc_assert (ctx.all_marked (dfs));
> +
> + 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 unsigned length = cov_length (cov);
> + for (unsigned i = 0; i < length; i++)
> + masking_vectors (ctx, cov_blocks (cov, i), cov_masks (cov, i));
> +
> + return cov;
> +}
> +
> +int
> +instrument_decisions (array_slice<basic_block> expr, unsigned condno,
> + tree *accu, gcov_type_unsigned *masks)
> +{
> + /* Zero the local accumulators. */
> + tree zero = build_int_cst (get_gcov_type (), 0);
> + for (edge e : expr[0]->succs)
> + {
> + gsi_insert_on_edge (e, gimple_build_assign (accu[0], zero));
> + gsi_insert_on_edge (e, gimple_build_assign (accu[1], zero));
> + }
> + /* Add instructions for updating the function-local accumulators. */
> + for (size_t i = 0; i < expr.size (); i++)
> + {
> + for (edge e : expr[i]->succs)
> + {
> + if (!edge_conditional_p (e))
> + continue;
> +
> + /* accu |= expr[i] */
> + const int k = condition_index (e->flags);
> + tree rhs = build_int_cst (gcov_type_node, 1ULL << i);
> + emit_bitwise_op (e, accu[k], accu[k], BIT_IOR_EXPR, rhs);
> +
> + if (masks[2*i + k] == 0)
> + continue;
> +
> + /* accu &= mask[i] */
> + tree mask = build_int_cst (gcov_type_node, ~masks[2*i + k]);
> + for (int j = 0; j < 2; j++)
> + emit_bitwise_op (e, accu[j], accu[j], BIT_AND_EXPR, mask);
> + }
> + }
> +
> + 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);
> +
> + /* Add instructions for flushing the local accumulators.
> +
> + It is important that the flushes happen on on the outcome's incoming
> + edges, otherwise flushes could be lost to exception handling.
> +
> + void fn (int a)
> + {
> + if (a)
> + fclose();
> + exit();
> + }
> +
> + Can yield the CFG:
> + A
> + |\
> + | B
> + |/
> + e
> +
> + This typically only happen in optimized builds, but gives linker errors
> + because the counter is left as an undefined symbol. */
> +
> + outcomes out = conditional_succs (expr.back ());
> + const basic_block outcome_blocks[] = { out.t, out.t, out.f, out.f, };
> + const int outcome[] = { 0, 1, 0, 1 };
> + for (int i = 0; i < 4; i++)
> + {
> + const int k = outcome[i];
> + for (edge e : outcome_blocks[i]->preds)
> + {
> + /* The outcome may have been split and we want to check if the
> + edge is sourced from inside the expression, so contract it to
> + find the source conditional edge. */
> + e = contract_edge_up (e);
> +
> + /* Only instrument edges from inside the expression. Sometimes
> + complicated control flow (like sigsetjmp and gotos) add
> + predecessors that don't come from the boolean expression. */
> + if (index_of (e->src, expr) == -1)
> + continue;
> +
> + tree ref = tree_coverage_counter_ref (GCOV_COUNTER_CONDS,
> + 2*condno + k);
> + tree tmp = make_temp_ssa_name (gcov_type_node, NULL,
> + "__conditions_tmp");
> + if (atomic)
> + {
> + tree relaxed = build_int_cst (integer_type_node,
> + MEMMODEL_RELAXED);
> + ref = unshare_expr (ref);
> + gassign *read = gimple_build_assign (tmp, accu[k]);
> + gcall *flush = gimple_build_call (atomic_ior, 3,
> + build_addr (ref),
> + gimple_assign_lhs (read),
> + relaxed);
> +
> + gsi_insert_on_edge (e, read);
> + gsi_insert_on_edge (e, flush);
> + }
> + else
> + {
> + gassign *read = gimple_build_assign (tmp, ref);
> + tmp = gimple_assign_lhs (read);
> + gsi_insert_on_edge (e, read);
> + ref = unshare_expr (ref);
> + emit_bitwise_op (e, ref, accu[k], BIT_IOR_EXPR, tmp);
> + }
> + }
> + }
> + return expr.size ();
> +}
> +
> +#undef CONDITIONS_MAX_TERMS
> +#undef EDGE_CONDITION
> +
> /* Do initialization work for the edge profiler. */
>
> /* Add code:
> @@ -758,7 +1802,7 @@ 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 || profile_condition_flag)
> expand_thunk (node, false, true);
> /* Read cgraph profile but keep function as thunk at profile-use
> time. */
> @@ -803,7 +1847,7 @@ 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 || profile_condition_flag || flag_test_coverage)
> FOR_EACH_DEFINED_FUNCTION (node)
> {
> if (!gimple_has_body_p (node->decl)
> @@ -897,7 +1941,7 @@ 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 || profile_condition_flag));
> }
>
> } // anon namespace
> diff --git a/libgcc/libgcov-merge.c b/libgcc/libgcov-merge.c
> index 89741f637e1..9e3e8ee5657 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))) {}
Gentle ping. I have a tuned the summary output slightly (decisions covered ->
condition outcomes covered) already.
next prev parent reply other threads:[~2022-10-25 6:33 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-12 10:16 Jørgen Kvalsvik
2022-10-18 0:17 ` Hans-Peter Nilsson
2022-10-18 10:13 ` Jørgen Kvalsvik
2022-10-25 6:33 ` Jørgen Kvalsvik [this message]
2022-10-27 10:34 ` Ping " Martin Liška
2022-11-02 6:16 ` Jørgen Kvalsvik
2022-11-09 20:08 ` [Ping 2][PATCH] " Jørgen Kvalsvik
2022-11-10 14:19 ` Ping [PATCH] " Martin Liška
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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).