The following is another issue with macros from system headers. In this case bool is defined in a system header to expand to _Bool and the "is promoted to" warning didn't trigger because of that. The fix is to use the expanded location.
Bootstrapped/regtested on x86_64-linux, ok for trunk? 2016-02-24 Marek Polacek <pola...@redhat.com> PR c/67854 * gimplify.c (gimplify_va_arg_expr): Use expanded location for the "is promoted to" warning. * gcc.dg/pr67854.c: New test. diff --git gcc/gimplify.c gcc/gimplify.c index 7be6bd7..e7ea974 100644 --- gcc/gimplify.c +++ gcc/gimplify.c @@ -11573,24 +11573,28 @@ gimplify_va_arg_expr (tree *expr_p, gimple_seq *pre_p, { static bool gave_help; bool warned; + /* Use the expansion point to handle cases such as passing bool (defined + in a system header) through `...'. */ + source_location xloc + = expansion_point_location_if_in_system_header (loc); /* Unfortunately, this is merely undefined, rather than a constraint violation, so we cannot make this an error. If this call is never executed, the program is still strictly conforming. */ - warned = warning_at (loc, 0, - "%qT is promoted to %qT when passed through %<...%>", + warned = warning_at (xloc, 0, + "%qT is promoted to %qT when passed through %<...%>", type, promoted_type); if (!gave_help && warned) { gave_help = true; - inform (loc, "(so you should pass %qT not %qT to %<va_arg%>)", + inform (xloc, "(so you should pass %qT not %qT to %<va_arg%>)", promoted_type, type); } /* We can, however, treat "undefined" any way we please. Call abort to encourage the user to fix the program. */ if (warned) - inform (loc, "if this code is reached, the program will abort"); + inform (xloc, "if this code is reached, the program will abort"); /* Before the abort, allow the evaluation of the va_list expression to exit or longjmp. */ gimplify_and_add (valist, pre_p); diff --git gcc/testsuite/gcc.dg/pr67854.c gcc/testsuite/gcc.dg/pr67854.c index e69de29..af994c6 100644 --- gcc/testsuite/gcc.dg/pr67854.c +++ gcc/testsuite/gcc.dg/pr67854.c @@ -0,0 +1,11 @@ +/* PR c/67854 */ +/* { dg-do compile } */ + +#include <stdbool.h> +#include <stdarg.h> + +void +foo (va_list ap) +{ + va_arg (ap, bool); /* { dg-warning "is promoted to .int. when passed through" } */ +} Marek