Hi! As the following testcase shows, with -w we don't emit -Wbuiltin-declaration-mismatch warnings (correct), but emit weird messages: ~/src/gcc/obj46/gcc/xgcc -B ~/src/gcc/obj46/gcc/ -w pr89525.c -S pr89525.c: In function ‘foo’: pr89525.c:5:8: note: declared here 5 | double sqrt (); /* { dg-bogus "declared here" } */ | ^~~~
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2019-02-27 Jakub Jelinek <ja...@redhat.com> PR c/89525 * c-typeck.c (convert_arguments): Call inform_declaration only if the previous warning_at call returned true. * gcc.dg/pr89525.c: New test. --- gcc/c/c-typeck.c.jj 2019-01-24 20:15:16.913439861 +0100 +++ gcc/c/c-typeck.c 2019-02-27 21:33:37.815873072 +0100 @@ -3509,12 +3509,10 @@ convert_arguments (location_t loc, vec<l if (builtin_type == void_type_node) { - warning_at (loc, OPT_Wbuiltin_declaration_mismatch, - "too many arguments to built-in function %qE " - "expecting %d", - function, parmnum); - - inform_declaration (fundecl); + if (warning_at (loc, OPT_Wbuiltin_declaration_mismatch, + "too many arguments to built-in function %qE " + "expecting %d", function, parmnum)) + inform_declaration (fundecl); builtin_typetail = NULL_TREE; } @@ -3651,10 +3649,10 @@ convert_arguments (location_t loc, vec<l for (tree t = builtin_typetail; t; t = TREE_CHAIN (t)) ++nargs; - warning_at (loc, OPT_Wbuiltin_declaration_mismatch, - "too few arguments to built-in function %qE expecting %u", - function, nargs - 1); - inform_declaration (fundecl); + if (warning_at (loc, OPT_Wbuiltin_declaration_mismatch, + "too few arguments to built-in function %qE " + "expecting %u", function, nargs - 1)) + inform_declaration (fundecl); } return error_args ? -1 : (int) parmnum; --- gcc/testsuite/gcc.dg/pr89525.c.jj 2019-02-27 21:34:45.863757616 +0100 +++ gcc/testsuite/gcc.dg/pr89525.c 2019-02-27 21:34:24.232112209 +0100 @@ -0,0 +1,11 @@ +/* PR c/89525 */ +/* { dg-do compile } */ +/* { dg-options "-w" } */ + +double sqrt (); /* { dg-bogus "declared here" } */ + +void +foo (void) +{ + sqrt (); +} Jakub