diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 3feb910..a3dae34 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -47,6 +47,7 @@ along with GCC; see the file COPYING3. If not see #include "gimplify.h" #include "substring-locations.h" #include "spellcheck.h" +#include "gcc-rich-location.h" cpp_reader *parse_in; /* Declared in c-pragma.h. */ @@ -13057,4 +13058,76 @@ diagnose_mismatched_attributes (tree olddecl, tree newdecl) return warned; } +/* Warn if an argument at position param_pos is passed to a + restrict-qualified param, and it aliases with another argument. */ + +void +warn_for_restrict (unsigned param_pos, vec *args) +{ + tree arg = (*args)[param_pos]; + if (TREE_VISITED (arg) || operand_equal_p (arg, null_pointer_node, 0)) + return; + + location_t loc = EXPR_LOC_OR_LOC (arg, input_location); + gcc_rich_location richloc (loc); + + unsigned i; + tree current_arg; + auto_vec arg_positions; + + FOR_EACH_VEC_ELT (*args, i, current_arg) + { + if (i == param_pos) + continue; + + tree current_arg = (*args)[i]; + if (operand_equal_p (arg, current_arg, 0)) + { + TREE_VISITED (current_arg) = 1; + arg_positions.safe_push (i); + } + } + + if (arg_positions.is_empty ()) + return; + + struct obstack fmt_obstack; + gcc_obstack_init (&fmt_obstack); + char *fmt = (char *) obstack_alloc (&fmt_obstack, 0); + + char num[32]; + sprintf (num, "%u", param_pos + 1); + + obstack_grow (&fmt_obstack, "passing argument ", + strlen ("passing argument ")); + obstack_grow (&fmt_obstack, num, strlen (num)); + obstack_grow (&fmt_obstack, + " to restrict-qualified parameter aliases with argument", + strlen (" to restrict-qualified parameter " + "aliases with argument")); + + /* make argument plural and append space. */ + if (arg_positions.length () > 1) + obstack_1grow (&fmt_obstack, 's'); + obstack_1grow (&fmt_obstack, ' '); + + unsigned pos; + FOR_EACH_VEC_ELT (arg_positions, i, pos) + { + tree arg = (*args)[pos]; + if (EXPR_HAS_LOCATION (arg)) + richloc.add_range (EXPR_LOCATION (arg), false); + + sprintf (num, "%u", pos + 1); + obstack_grow (&fmt_obstack, num, strlen (num)); + + if (i < arg_positions.length () - 1) + obstack_grow (&fmt_obstack, ", ", strlen (", ")); + } + + obstack_1grow (&fmt_obstack, 0); + warning_at_rich_loc (&richloc, OPT_Wrestrict, fmt); + obstack_free (&fmt_obstack, fmt); +} + #include "gt-c-family-c-common.h" diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h index bc22baa..cdb762e 100644 --- a/gcc/c-family/c-common.h +++ b/gcc/c-family/c-common.h @@ -920,6 +920,7 @@ extern void c_parse_final_cleanups (void); extern void warn_for_omitted_condop (location_t, tree); extern void warn_for_memset (location_t, tree, tree, int); +extern void warn_for_restrict (unsigned, vec *); /* These macros provide convenient access to the various _STMT nodes. */ diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt index a5358ed..5ec3a25 100644 --- a/gcc/c-family/c.opt +++ b/gcc/c-family/c.opt @@ -1012,6 +1012,11 @@ Wduplicate-decl-specifier C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall) Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier. +Wrestrict +C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) +Warn when an argument passed to a restrict-qualified parameter aliases with +another argument. + ansi C ObjC C++ ObjC++ A synonym for -std=c89 (for C) or -std=c++98 (for C++). diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c index fe0c95f..05510f6 100644 --- a/gcc/c/c-parser.c +++ b/gcc/c/c-parser.c @@ -8369,6 +8369,25 @@ c_parser_postfix_expression_after_primary (c_parser *parser, warn_for_memset (expr_loc, arg0, arg2, literal_zero_mask); } + if (TREE_CODE (expr.value) == FUNCTION_DECL && warn_restrict) + { + unsigned i; + tree arg; + FOR_EACH_VEC_SAFE_ELT (exprlist, i, arg) + TREE_VISITED (arg) = 0; + + unsigned param_pos = 0; + function_args_iterator iter; + tree t; + FOREACH_FUNCTION_ARGS (TREE_TYPE (expr.value), t, iter) + { + if (POINTER_TYPE_P (t) && TYPE_RESTRICT (t) + && !TYPE_READONLY (TREE_TYPE (t))) + warn_for_restrict (param_pos, exprlist); + param_pos++; + } + } + start = expr.get_start (); finish = parser->tokens_buf[0].get_finish (); expr.value diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 690e928..ab73655 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -6878,6 +6878,26 @@ cp_parser_postfix_expression (cp_parser *parser, bool address_p, bool cast_p, warn_for_memset (input_location, arg0, arg2, literal_mask); } + if (TREE_CODE (postfix_expression) == FUNCTION_DECL + && warn_restrict) + { + unsigned i; + tree arg; + FOR_EACH_VEC_SAFE_ELT (args, i, arg) + TREE_VISITED (arg) = 0; + + unsigned param_pos = 0; + for (tree decl = DECL_ARGUMENTS (postfix_expression); + decl != NULL_TREE; + decl = DECL_CHAIN (decl), param_pos++) + { + tree type = TREE_TYPE (decl); + if (POINTER_TYPE_P (type) && TYPE_RESTRICT (type) + && !TYPE_READONLY (TREE_TYPE (type))) + warn_for_restrict (param_pos, args); + } + } + if (TREE_CODE (postfix_expression) == COMPONENT_REF) { tree instance = TREE_OPERAND (postfix_expression, 0); diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 1f04501..869bf07 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -288,7 +288,7 @@ Objective-C and Objective-C++ Dialects}. -Wparentheses -Wno-pedantic-ms-format @gol -Wplacement-new -Wplacement-new=@var{n} @gol -Wpointer-arith -Wno-pointer-to-int-cast @gol --Wno-pragmas -Wredundant-decls -Wno-return-local-addr @gol +-Wno-pragmas -Wredundant-decls -Wrestrict -Wno-return-local-addr @gol -Wreturn-type -Wsequence-point -Wshadow -Wno-shadow-ivar @gol -Wshift-overflow -Wshift-overflow=@var{n} @gol -Wshift-count-negative -Wshift-count-overflow -Wshift-negative-value @gol @@ -5274,6 +5274,12 @@ compilations. Warn when deleting a pointer to incomplete type, which may cause undefined behavior at runtime. This warning is enabled by default. +@item -Wrestrict +@opindex Wrestrict +@opindex Wno-restrict +Warn when an argument passed to a restrict-qualified parameter +aliases with another argument + @item -Wuseless-cast @r{(C++ and Objective-C++ only)} @opindex Wuseless-cast @opindex Wno-useless-cast diff --git a/gcc/testsuite/c-c++-common/pr35503-1.c b/gcc/testsuite/c-c++-common/pr35503-1.c new file mode 100644 index 0000000..25e3721 --- /dev/null +++ b/gcc/testsuite/c-c++-common/pr35503-1.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-Wrestrict" } */ + +int foo (char *__restrict buf, const char *__restrict fmt, ...); + +void f(void) +{ + char buf[100] = "hello"; + foo (buf, "%s-%s", buf, "world"); /* { dg-warning "passing argument 1 to restrict-qualified parameter aliases with argument 3" } */ +} diff --git a/gcc/testsuite/c-c++-common/pr35503-2.c b/gcc/testsuite/c-c++-common/pr35503-2.c new file mode 100644 index 0000000..bfcd944 --- /dev/null +++ b/gcc/testsuite/c-c++-common/pr35503-2.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-fdiagnostics-show-caret -Wrestrict" } */ + +void f(int *__restrict x, int *y, int *__restrict z, int *w); + +void foo(int alpha, int beta) +{ + f (&alpha, &beta, &alpha, &alpha); /* { dg-warning "passing argument 1 to restrict-qualified parameter aliases with arguments 3, 4" } */ + +/* { dg-begin-multiline-output "" } + f (&alpha, &beta, &alpha, &alpha); + ^~~~~~ ~~~~~~ ~~~~~~ + { dg-end-multiline-output "" } */ +} diff --git a/gcc/testsuite/c-c++-common/pr35503-3.c b/gcc/testsuite/c-c++-common/pr35503-3.c new file mode 100644 index 0000000..8cbacab --- /dev/null +++ b/gcc/testsuite/c-c++-common/pr35503-3.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-Wrestrict" } */ + +void f(int *x, int *__restrict y); + +void foo(int a) +{ + f (&a, &a); /* { dg-warning "passing argument 2 to restrict-qualified parameter aliases with argument 1" } */ +}