c++: Fix up ICE in emit_support_tinfo_1 [PR109042]
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Commit Message
Hi!
In my recent rtti.cc change I assumed when emitting the support tinfos
that the tinfos for the fundamental types haven't been created yet.
Normally (in libsupc++.a (fundamental_type_info.o)) that is the case,
but as can be seen on the testcase, one can violate it by using typeid
etc. in the same TU and do it before ~__fundamental_type_info ()
definition.
The following patch fixes that by popping from unemitted_tinfo_decls
only in the normal case when it is there, and treating non-NULL
DECL_INITIAL on a tinfo node as indication that emit_tinfo_decl has
processed it already.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2023-03-07 Jakub Jelinek <jakub@redhat.com>
PR c++/109042
* rtti.cc (emit_support_tinfo_1): Don't assert that last
unemitted_tinfo_decls element is tinfo, instead pop from it only in
that case.
* decl2.cc (c_parse_final_cleanups): Don't call emit_tinfo_decl
for unemitted_tinfO_decls which have already non-NULL DECL_INITIAL.
* g++.dg/rtti/pr109042.C: New test.
Jakub
Comments
On 3/7/23 04:07, Jakub Jelinek wrote:
> Hi!
>
> In my recent rtti.cc change I assumed when emitting the support tinfos
> that the tinfos for the fundamental types haven't been created yet.
> Normally (in libsupc++.a (fundamental_type_info.o)) that is the case,
> but as can be seen on the testcase, one can violate it by using typeid
> etc. in the same TU and do it before ~__fundamental_type_info ()
> definition.
>
> The following patch fixes that by popping from unemitted_tinfo_decls
> only in the normal case when it is there, and treating non-NULL
> DECL_INITIAL on a tinfo node as indication that emit_tinfo_decl has
> processed it already.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2023-03-07 Jakub Jelinek <jakub@redhat.com>
>
> PR c++/109042
> * rtti.cc (emit_support_tinfo_1): Don't assert that last
> unemitted_tinfo_decls element is tinfo, instead pop from it only in
> that case.
> * decl2.cc (c_parse_final_cleanups): Don't call emit_tinfo_decl
> for unemitted_tinfO_decls which have already non-NULL DECL_INITIAL.
>
> * g++.dg/rtti/pr109042.C: New test.
>
> --- gcc/cp/rtti.cc.jj 2023-03-03 00:34:52.028567946 +0100
> +++ gcc/cp/rtti.cc 2023-03-06 19:06:27.433307136 +0100
> @@ -1581,10 +1581,10 @@ emit_support_tinfo_1 (tree bltn)
> /* Emit it right away if not emitted already. */
> if (DECL_INITIAL (tinfo) == NULL_TREE)
> {
> - gcc_assert (unemitted_tinfo_decls->last () == tinfo);
> bool ok = emit_tinfo_decl (tinfo);
> gcc_assert (ok);
> - unemitted_tinfo_decls->pop ();
> + if (unemitted_tinfo_decls->last () == tinfo)
> + unemitted_tinfo_decls->pop ();
So if it's not last we'll leave it in the vec, even though it is no
longer unemitted, and let c_parse_final_cleanups deal with removing it?
That could use a comment. OK with that change.
> }
> }
> }
> --- gcc/cp/decl2.cc.jj 2023-01-18 16:11:47.053213397 +0100
> +++ gcc/cp/decl2.cc 2023-03-06 19:07:16.830582984 +0100
> @@ -4982,7 +4982,7 @@ c_parse_final_cleanups (void)
> get emitted. */
> for (i = unemitted_tinfo_decls->length ();
> unemitted_tinfo_decls->iterate (--i, &t);)
> - if (emit_tinfo_decl (t))
> + if (DECL_INITIAL (t) || emit_tinfo_decl (t))
> {
> reconsider = true;
> unemitted_tinfo_decls->unordered_remove (i);
> --- gcc/testsuite/g++.dg/rtti/pr109042.C.jj 2023-03-06 19:11:06.995208812 +0100
> +++ gcc/testsuite/g++.dg/rtti/pr109042.C 2023-03-06 19:10:59.117324298 +0100
> @@ -0,0 +1,20 @@
> +// PR c++/109042
> +// { dg-do compile }
> +
> +namespace std { class type_info {}; }
> +
> +std::type_info
> +foo ()
> +{
> + return typeid (void);
> +}
> +
> +namespace __cxxabiv1 {
> + struct __fundamental_type_info {
> + virtual ~__fundamental_type_info ();
> + };
> +
> + __fundamental_type_info::~__fundamental_type_info ()
> + {
> + }
> +}
>
> Jakub
>
@@ -1581,10 +1581,10 @@ emit_support_tinfo_1 (tree bltn)
/* Emit it right away if not emitted already. */
if (DECL_INITIAL (tinfo) == NULL_TREE)
{
- gcc_assert (unemitted_tinfo_decls->last () == tinfo);
bool ok = emit_tinfo_decl (tinfo);
gcc_assert (ok);
- unemitted_tinfo_decls->pop ();
+ if (unemitted_tinfo_decls->last () == tinfo)
+ unemitted_tinfo_decls->pop ();
}
}
}
@@ -4982,7 +4982,7 @@ c_parse_final_cleanups (void)
get emitted. */
for (i = unemitted_tinfo_decls->length ();
unemitted_tinfo_decls->iterate (--i, &t);)
- if (emit_tinfo_decl (t))
+ if (DECL_INITIAL (t) || emit_tinfo_decl (t))
{
reconsider = true;
unemitted_tinfo_decls->unordered_remove (i);
@@ -0,0 +1,20 @@
+// PR c++/109042
+// { dg-do compile }
+
+namespace std { class type_info {}; }
+
+std::type_info
+foo ()
+{
+ return typeid (void);
+}
+
+namespace __cxxabiv1 {
+ struct __fundamental_type_info {
+ virtual ~__fundamental_type_info ();
+ };
+
+ __fundamental_type_info::~__fundamental_type_info ()
+ {
+ }
+}