Hi!
When a C++17 inline static data member has a redundant out-of-class
deprecated redeclaration, we can end up with 2 DW_TAG_variable in
DW_TAG_compile_unit, one DW_AT_declaration and one with DW_AT_specification
pointing to it (the latter emitted for the redeclaration), before
gen_member_die can do its job. In there we want to move the declaration
DIE into the class and have a CU child DW_TAG_variable that has
DW_AT_specification pointing to it. But in this case we've put
the DIE with DW_AT_specification into the hash table and gen_member_die
ICEs in splice_child_die. The following patch handles that case gracefully,
by moving the DW_AT_declaration DIE into the class instead of trying to
move the DW_AT_specification one, and by making sure we don't create
yet another DIE with DW_AT_specification because we already have one.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2017-03-29 Jakub Jelinek <ja...@redhat.com>
PR debug/80234
* dwarf2out.c (gen_member_die): Handle C++17 inline static data
members with redundant out-of-class redeclaration.
* g++.dg/debug/dwarf2/pr80234-1.C: New test.
* g++.dg/debug/dwarf2/pr80234-2.C: New test.
--- gcc/dwarf2out.c.jj 2017-03-24 14:17:59.000000000 +0100
+++ gcc/dwarf2out.c 2017-03-29 17:19:08.513497649 +0200
@@ -24085,6 +24085,10 @@ gen_member_die (tree type, dw_die_ref co
for (member = TYPE_FIELDS (type); member; member = DECL_CHAIN (member))
{
struct vlr_context vlr_ctx = { type, NULL_TREE };
+ bool static_inline_p
+ = (TREE_STATIC (member)
+ && (lang_hooks.decls.decl_dwarf_attribute (member, DW_AT_inline)
+ != -1));
/* If we thought we were generating minimal debug info for TYPE
and then changed our minds, some of the member declarations
@@ -24096,9 +24100,33 @@ gen_member_die (tree type, dw_die_ref co
{
/* Handle inline static data members, which only have in-class
declarations. */
+ dw_die_ref ref = NULL;
+ if (child->die_tag == DW_TAG_variable
+ && child->die_parent == comp_unit_die ())
+ {
+ ref = get_AT_ref (child, DW_AT_specification);
+ /* For C++17 inline static data members followed by redundant
+ out of class redeclaration, we might get here with
+ child being the DIE created for the out of class
+ redeclaration and with its DW_AT_specification being
+ the DIE created for in-class definition. We want to
+ reparent the latter, and don't want to create another
+ DIE with DW_AT_specification in that case, because
+ we already have one. */
+ if (ref
+ && static_inline_p
+ && ref->die_tag == DW_TAG_variable
+ && ref->die_parent == comp_unit_die ()
+ && get_AT (ref, DW_AT_specification) == NULL)
+ {
+ child = ref;
+ ref = NULL;
+ static_inline_p = false;
+ }
+ }
if (child->die_tag == DW_TAG_variable
&& child->die_parent == comp_unit_die ()
- && get_AT (child, DW_AT_specification) == NULL)
+ && ref == NULL)
{
reparent_child (child, context_die);
if (dwarf_version < 5)
@@ -24126,9 +24154,7 @@ gen_member_die (tree type, dw_die_ref co
/* For C++ inline static data members emit immediately a DW_TAG_variable
DIE that will refer to that DW_TAG_member/DW_TAG_variable through
DW_AT_specification. */
- if (TREE_STATIC (member)
- && (lang_hooks.decls.decl_dwarf_attribute (member, DW_AT_inline)
- != -1))
+ if (static_inline_p)
{
int old_extern = DECL_EXTERNAL (member);
DECL_EXTERNAL (member) = 0;
--- gcc/testsuite/g++.dg/debug/dwarf2/pr80234-1.C.jj 2017-03-29
17:23:43.606901317 +0200
+++ gcc/testsuite/g++.dg/debug/dwarf2/pr80234-1.C 2017-03-29
17:22:51.000000000 +0200
@@ -0,0 +1,15 @@
+// PR debug/80234
+// { dg-do compile }
+// { dg-options "-gdwarf-4 -std=c++17" }
+
+struct S
+{
+ static constexpr const char n = 'S';
+ virtual ~S ();
+};
+
+constexpr const char S::n;
+
+S::~S()
+{
+}
--- gcc/testsuite/g++.dg/debug/dwarf2/pr80234-2.C.jj 2017-03-29
17:23:54.663756769 +0200
+++ gcc/testsuite/g++.dg/debug/dwarf2/pr80234-2.C 2017-03-29
17:23:59.818689378 +0200
@@ -0,0 +1,15 @@
+// PR debug/80234
+// { dg-do compile }
+// { dg-options "-gdwarf-5 -std=c++17" }
+
+struct S
+{
+ static constexpr const char n = 'S';
+ virtual ~S ();
+};
+
+constexpr const char S::n;
+
+S::~S()
+{
+}
Jakub
