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ipa-sra: Prevent constructing debug info from wrong argument

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The mechanism generating debug info for removed parameters did not
adjust index of the argument in the call statement to take into
account extra arguments IPA-SRA might have produced when splitting a
strucutre.  This patch addresses that omission and stops gdb from
showing incorrect value for the removed parameter and says "value
optimized out" instead.  The guality testcase will end up as
UNSUPPORTED in the results which is how Richi told me on IRC we deal
with this.

It is possible to generate debug info to actually show the value of
the removed parameter but so far my approaches to do just that seem
toocontroversial
(https://gcc.gnu.org/pipermail/gcc-patches/2020-May/546705.html), so
before I come up with something better I'd like to push this to master
and the gcc-10 branch in time for the GCC 10.2 release.

gcc/ChangeLog:

2020-07-01  Martin Jambor  <mjambor@suse.cz>

	PR debug/95343
	* ipa-param-manipulation.c (ipa_param_adjustments::modify_call): Adjust
	argument index if necessary.

gcc/testsuite/ChangeLog:

2020-07-01  Martin Jambor  <mjambor@suse.cz>

	PR debug/95343
	* gcc.dg/guality/pr95343.c: New test.
This commit is contained in:
Martin Jambor 2020-07-02 14:30:50 +02:00
parent 1ac9258cca
commit 053c88093a
2 changed files with 50 additions and 1 deletions
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6
gcc/ipa-param-manipulation.c
View file

@ -790,7 +790,11 @@ ipa_param_adjustments::modify_call (gcall *stmt,
if (!is_gimple_reg (old_parm) || kept[i])
continue;
tree origin = DECL_ORIGIN (old_parm);
tree arg = gimple_call_arg (stmt, i);
tree arg;
if (transitive_remapping)
arg = gimple_call_arg (stmt, index_map[i]);
else
arg = gimple_call_arg (stmt, i);
if (!useless_type_conversion_p (TREE_TYPE (origin), TREE_TYPE (arg)))
{

45
gcc/testsuite/gcc.dg/guality/pr95343.c Normal file
View file

@ -0,0 +1,45 @@
/* { dg-do run } */
/* { dg-options "-g -fno-ipa-icf" } */
volatile int v;
int __attribute__((noipa))
get_val0 (void) {return 0;}
int __attribute__((noipa))
get_val2 (void) {return 2;}
struct S
{
int a, b, c;
};
static int __attribute__((noinline))
bar (struct S s, int x, int y, int z, int i)
{
int r;
v = s.a + s.b; /* { dg-final { gdb-test . "i+1" "3" } } */
return r;
}
static int __attribute__((noinline))
foo (struct S s, int i)
{
int r;
r = bar (s, 3, 4, 5, i);
return r;
}
int
main (void)
{
struct S s;
int i;
i = get_val2 ();
s.a = get_val0 ();
s.b = get_val0 ();
s.c = get_val0 ();
int r = foo (s, i);
v = r + i;
return 0;
}