From 269adb9dea5b2ded168fb9ca12bd29c4e217d241 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Fri, 20 Nov 2015 10:51:35 -0500 Subject: [PATCH] c-common.c (shorten_compare): But look through macros from system headers. * c-common.c (shorten_compare): But look through macros from system headers. From-SVN: r230665 --- gcc/c-family/ChangeLog | 5 +++++ gcc/c-family/c-common.c | 6 ++++-- gcc/testsuite/gcc.dg/Wtype-limits2.c | 12 ++++++++++++ 3 files changed, 21 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/Wtype-limits2.c diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index 5ca75b4dbf0..c19cafa05f8 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,8 @@ +2015-11-19 Jason Merrill + + * c-common.c (shorten_compare): But look through macros from + system headers. + 2015-11-18 Jason Merrill * c-common.c (shorten_compare): Don't -Wtype-limits if the diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 068a0bcd2ec..fe0a235988f 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -4651,8 +4651,10 @@ shorten_compare (location_t loc, tree *op0_ptr, tree *op1_ptr, } if (TREE_CODE (primop0) != INTEGER_CST - /* Don't warn if it's from a macro. */ - && !from_macro_expansion_at (EXPR_LOCATION (primop0))) + /* Don't warn if it's from a (non-system) macro. */ + && !(from_macro_expansion_at + (expansion_point_location_if_in_system_header + (EXPR_LOCATION (primop0))))) { if (val == truthvalue_false_node) warning_at (loc, OPT_Wtype_limits, diff --git a/gcc/testsuite/gcc.dg/Wtype-limits2.c b/gcc/testsuite/gcc.dg/Wtype-limits2.c new file mode 100644 index 00000000000..92151aa68c9 --- /dev/null +++ b/gcc/testsuite/gcc.dg/Wtype-limits2.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-Wtype-limits" } */ +/* { dg-require-effective-target sync_char_short } */ + +#include + +unsigned foo (unsigned char *x) +{ + if (atomic_load (x) > 1000) /* { dg-warning "comparison is always false due to limited range of data type" } */ + return 0; + return 1; +} -- 2.30.2