Hi!
As mentioned in the PR, we don't guarantee DECL_UID to be the same between
corresponding decls in -g and -g0 builds, -g can create more decls and all
that is guaranteed is that the DECL_UIDs of the corresponding decls compare
the same.
The following testcase gets a -fcompare-debug failure because these
functions use DECL_UID as the number in ASM_FORMAT_PRIVATE_NAME.
The patch fixes it by using just a sequential number there instead.
I don't think this can be called during PCH writing, this only happens for
non-public decls and the C/C++ FEs shouldn't mangling those at that point
(furthermore C++ FE uses a different set_decl_assembler_name hook and this
one is something only the gimplifier calls on C.NNNN temporaries.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2020-03-25 Jakub Jelinek <ja...@redhat.com>
PR c++/94223
* langhooks.c (lhd_set_decl_assembler_name): Use a static ulong
counter instead of DECL_UID.
* lto-lang.c (lto_set_decl_assembler_name): Use a static ulong
counter instead of DECL_UID.
* g++.dg/opt/pr94223.C: New test.
--- gcc/langhooks.c.jj 2020-01-12 11:54:36.670409531 +0100
+++ gcc/langhooks.c 2020-03-24 16:05:26.728284808 +0100
@@ -160,16 +160,17 @@ lhd_set_decl_assembler_name (tree decl)
Can't use just the variable's own name for a variable whose scope
is less than the whole compilation. Concatenate a distinguishing
- number - we use the DECL_UID. */
+ number. */
if (TREE_PUBLIC (decl) || DECL_FILE_SCOPE_P (decl))
id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
else
{
const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
+ static unsigned long num;
char *label;
- ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
+ ASM_FORMAT_PRIVATE_NAME (label, name, num++);
id = get_identifier (label);
}
--- gcc/lto/lto-lang.c.jj 2020-01-12 11:54:36.678409411 +0100
+++ gcc/lto/lto-lang.c 2020-03-24 13:55:10.463826320 +0100
@@ -1179,8 +1179,9 @@ lto_set_decl_assembler_name (tree decl)
{
const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
char *label;
+ static unsigned long num;
- ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
+ ASM_FORMAT_PRIVATE_NAME (label, name, num++);
id = get_identifier (label);
}
--- gcc/testsuite/g++.dg/opt/pr94223.C.jj 2020-03-24 16:03:42.069863475
+0100
+++ gcc/testsuite/g++.dg/opt/pr94223.C 2020-03-24 16:04:53.327788620 +0100
@@ -0,0 +1,5 @@
+// PR c++/94223
+// { dg-do compile }
+// { dg-options "-O0 -std=c++2a -fcompare-debug" }
+
+#include "../cpp1z/init-statement6.C"
Jakub
