Hi,
Atm this test in pr45882.c:
...
int d = a[i]; /* { dg-final { gdb-test 16 "d" "112" } } */
...
fails as follows with -flto:
...
FAIL: gcc.dg/guality/pr45882.c -O2 -flto -fuse-linker-plugin \
-fno-fat-lto-objects line 16 d == 112
...
In more detail, gdb fails to print the value of d:
...
Breakpoint 1, foo (i=i@entry=7, j=j@entry=7) at pr45882.c:16
16 ++v;
$1 = <optimized out>
$2 = 112
<optimized out> != 112
...
Variable d is a local variable in function foo, initialized from global array a.
When compiling, first cddce1 removes the initialization of d in foo, given
that d is not used afterwards. Then ipa marks array a as write-only, and
removes the stores to array a in main. This invalidates the location
expression for d, which points to a[i], so it is removed, which is why gdb
ends up printing <optimized out> for d.
This patches fixes the fail by adding attribute used to array a, preventing
array a from being marked as write-only.
Tested on x86_64.
OK for trunk?
Thanks,
- Tom
[testsuite] Fix guality/pr45882.c for flto
2018-06-21 Tom de Vries <tdevr...@suse.de>
* gcc.dg/guality/pr45882.c (a): Add used attribute.
---
gcc/testsuite/gcc.dg/guality/pr45882.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/testsuite/gcc.dg/guality/pr45882.c
b/gcc/testsuite/gcc.dg/guality/pr45882.c
index 5ca22d4f4ad..ece35238a30 100644
--- a/gcc/testsuite/gcc.dg/guality/pr45882.c
+++ b/gcc/testsuite/gcc.dg/guality/pr45882.c
@@ -3,7 +3,7 @@
/* { dg-options "-g" } */
extern void abort (void);
-int a[1024];
+int a[1024] __attribute__((used));
volatile short int v;
__attribute__((noinline,noclone,used)) int
