From: Martin Uecker Date: Thu, 13 Apr 2023 17:35:15 +0000 (+0200) Subject: Reduce false positives for -Wnonnull for VLA parameters [PR98541] X-Git-Tag: basepoints/gcc-15~5024 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6e9ee44d96e5bda8808dd9d8ccf58d2525383f6b;p=thirdparty%2Fgcc.git Reduce false positives for -Wnonnull for VLA parameters [PR98541] This patch limits the warning about NULL arguments to VLA parameters declared [static n]. PR c/98541 gcc/ * gimple-ssa-warn-access.cc (pass_waccess::maybe_check_access_sizes): For VLA bounds in parameters, only warn about null pointers with 'static'. gcc/testsuite: * gcc.dg/Wnonnull-4.c: Adapt test. * gcc.dg/Wstringop-overflow-40.c: Adapt test. --- diff --git a/gcc/gimple-ssa-warn-access.cc b/gcc/gimple-ssa-warn-access.cc index e439d1b9b683..8b734295f09d 100644 --- a/gcc/gimple-ssa-warn-access.cc +++ b/gcc/gimple-ssa-warn-access.cc @@ -3477,27 +3477,14 @@ pass_waccess::maybe_check_access_sizes (rdwr_map *rwm, tree fndecl, tree fntype, if (integer_zerop (ptr)) { - if (sizidx >= 0 && tree_int_cst_sgn (sizrng[0]) > 0) + if (!access.second.internal_p + && sizidx >= 0 && tree_int_cst_sgn (sizrng[0]) > 0) { /* Warn about null pointers with positive sizes. This is different from also declaring the pointer argument with attribute nonnull when the function accepts null pointers only when the corresponding size is zero. */ - if (access.second.internal_p) - { - const std::string argtypestr - = access.second.array_as_string (ptrtype); - - if (warning_at (loc, OPT_Wnonnull, - "argument %i of variable length " - "array %s is null but " - "the corresponding bound argument " - "%i value is %s", - ptridx + 1, argtypestr.c_str (), - sizidx + 1, sizstr)) - arg_warned = OPT_Wnonnull; - } - else if (warning_at (loc, OPT_Wnonnull, + if (warning_at (loc, OPT_Wnonnull, "argument %i is null but " "the corresponding size argument " "%i value is %s", diff --git a/gcc/testsuite/gcc.dg/Wnonnull-4.c b/gcc/testsuite/gcc.dg/Wnonnull-4.c index 2c1c45a98567..1f14fbba45df 100644 --- a/gcc/testsuite/gcc.dg/Wnonnull-4.c +++ b/gcc/testsuite/gcc.dg/Wnonnull-4.c @@ -27,9 +27,9 @@ void test_fca_n (int r_m1) T ( 0); // Verify positive bounds. - T ( 1); // { dg-warning "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is 1" } - T ( 9); // { dg-warning "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is 9" } - T (max); // { dg-warning "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } + T ( 1); // { dg-bogus "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is 1" } + T ( 9); // { dg-bogus "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is 9" } + T (max); // { dg-bogus "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } } @@ -55,9 +55,9 @@ void test_fsa_x_n (int r_m1) T ( 0); // Verify positive bounds. - T ( 1); // { dg-warning "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is 1" } - T ( 9); // { dg-warning "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is 9" } - T (max); // { dg-warning "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } + T ( 1); // { dg-bogus "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is 1" } + T ( 9); // { dg-bogus "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is 9" } + T (max); // { dg-bogus "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } } @@ -83,9 +83,9 @@ void test_fia_1_n (int r_m1) T ( 0); // Verify positive bounds. - T ( 1); // { dg-warning "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is 1" } - T ( 9); // { dg-warning "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is 9" } - T (max); // { dg-warning "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } + T ( 1); // { dg-bogus "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is 1" } + T ( 9); // { dg-bogus "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is 9" } + T (max); // { dg-bogus "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } } @@ -111,9 +111,9 @@ void test_fla_3_n (int r_m1) T ( 0); // Verify positive bounds. - T ( 1); // { dg-warning "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is 1" } - T ( 9); // { dg-warning "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is 9" } - T (max); // { dg-warning "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } + T ( 1); // { dg-bogus "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is 1" } + T ( 9); // { dg-bogus "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is 9" } + T (max); // { dg-bogus "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } } @@ -139,9 +139,9 @@ void test_fda_n_5 (int r_m1) T ( 0); // Verify positive bounds. - T ( 1); // { dg-warning "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is 1" } - T ( 9); // { dg-warning "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is 9" } - T (max); // { dg-warning "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is \\d+" } + T ( 1); // { dg-bogus "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is 1" } + T ( 9); // { dg-bogus "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is 9" } + T (max); // { dg-bogus "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is \\d+" } } @@ -167,7 +167,7 @@ void test_fca_n_n (int r_m1) T ( 0); // Verify positive bounds. - T ( 1); // { dg-warning "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is 1" } - T ( 9); // { dg-warning "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is 9" } - T (max); // { dg-warning "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } + T ( 1); // { dg-bogus "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is 1" } + T ( 9); // { dg-bogus "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is 9" } + T (max); // { dg-bogus "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" } } diff --git a/gcc/testsuite/gcc.dg/Wstringop-overflow-40.c b/gcc/testsuite/gcc.dg/Wstringop-overflow-40.c index 386c92dc7a81..9e0ad1f3aff4 100644 --- a/gcc/testsuite/gcc.dg/Wstringop-overflow-40.c +++ b/gcc/testsuite/gcc.dg/Wstringop-overflow-40.c @@ -11,6 +11,7 @@ void fxa2 (int16_t[2]) __attribute__ ((nonnull)); void fas2 (int16_t[static 2]); void fvla (unsigned n, int16_t[n]); +void fvlaS (unsigned n, int16_t[static n]); void test_array_1_dim (void) { @@ -33,7 +34,8 @@ void test_array_1_dim (void) fas2 (a1); // { dg-warning "'fas2' accessing 4 bytes in a region of size 2 " } fas2 (&i); // { dg-warning "'fas2' accessing 4 bytes in a region of size 2 " } - fvla (1, 0); // { dg-warning "\\\[-Wnonnull" } + fvla (1, 0); + fvlaS (1, 0); // { dg-warning "\\\[-Wnonnull" } fvla (1, &i); fvla (2, a2); fvla (2, a1); // { dg-warning "'fvla' accessing 4 bytes in a region of size 2 " } @@ -47,6 +49,7 @@ void fxac2 (const int16_t[2]) __attribute__ ((nonnull)); void facs2 (const int16_t[static 2]); void fvlac (unsigned n, const int16_t[n]); +void fvlacS (unsigned n, const int16_t[static n]); void test_const_array_1_dim (void) { @@ -69,7 +72,8 @@ void test_const_array_1_dim (void) facs2 (a1); // { dg-warning "'facs2' reading 4 bytes from a region of size 2 " } facs2 (&i); // { dg-warning "'facs2' reading 4 bytes from a region of size 2 " } - fvlac (1, 0); // { dg-warning "\\\[-Wnonnull" } + fvlac (1, 0); + fvlacS (1, 0); // { dg-warning "\\\[-Wnonnull" } fvlac (1, &i); fvlac (2, a2); fvlac (2, a1); // { dg-warning "'fvlac' reading 4 bytes from a region of size 2 " }