[Bug lto/100010] New: ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans)

[Bug lto/100010] New: ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans)

[alex.miller at gmx dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

            Bug ID: 100010
           Summary: ICE in lto_output_node, at lto-cgraph.c:447
                    (-fdevirtualize-at-ltrans)
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
          Assignee: unassigned at gcc dot gnu.org
          Reporter: alex.miller at gmx dot de
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---

Building lcdf-typetools-2.108 fails with an ICE while linking the mmafm tool
(with gcc-10 using the flags "-O3 -flto -fdevirtualize-at-ltrans").

Here's a reduced sample that reproduces the issue (even with -O2):
---
struct String {
        String(char);
        ~String();
};
struct ErrorHandler {
        virtual String decorate(const String &);
};
String ErrorHandler::decorate(const String &str) {
        decorate(str);
        return 0;
}
struct LandmarkErrorHandler : ErrorHandler {
        String _landmark;
        LandmarkErrorHandler();
        String decorate(const String &);
};
String LandmarkErrorHandler::decorate(const String &) {
        return ErrorHandler::decorate(0);
}
struct Charstring {
        virtual ~Charstring();
        virtual void process() = 0;
} *interpret_cs;
Charstring::~Charstring() {}
struct : Charstring {
        void process() {}
} _cdv;
int main() {
        LandmarkErrorHandler();
        interpret_cs->process();
}
---

$ g++ -O2 -flto -fdevirtualize-at-ltrans a.cc
during IPA pass: static-var
lto1: internal compiler error: in lto_output_node, at lto-cgraph.c:447
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://bugs.gentoo.org/> for instructions.
lto-wrapper: fatal error: g++ returned 1 exit status
compilation terminated.
/usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../x86_64-pc-linux-gnu/bin/ld:
error: lto-wrapper failed
collect2: error: ld returned 1 exit status

Reducing the sources seems a bit brittle, like often with LTO:
* Combining all sources in a single file changed the error message to
  "lto1: internal compiler error: Segmentation fault", but minimizing made
  the error location reappear. The result is very similar to a multi-file
  reduction.
* Reduced sample fails with -O2, full sources need -O3.
* With g++-9.3.0 the reduced sample doesn't trigger the ICE, but the original
  sources do (at lto-cgraph.c:453).
Let me know if you need another sample.

[Bug lto/100010] [8/9/10/11 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |8.5
                 CC|                            |hubicka at gcc dot gnu.org
            Summary|ICE in lto_output_node, at  |[8/9/10/11 Regression] ICE
                   |lto-cgraph.c:447            |in lto_output_node, at
                   |(-fdevirtualize-at-ltrans)  |lto-cgraph.c:447
                   |                            |(-fdevirtualize-at-ltrans)
                   |                            |since
                   |                            |r6-6384-gceda2c69d5219719
   Last reconfirmed|                            |2021-04-11
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Confirmed, started with r6-6384-gceda2c69d5219719.

[Bug lto/100010] [8/9/10/11 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2
           Keywords|                            |ice-on-valid-code

[Bug lto/100010] [8/9/10/11 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |hubicka at gcc dot gnu.org

--- Comment #2 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
mine.

[Bug lto/100010] [9/10/11/12 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|8.5                         |9.4

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 8 branch is being closed.

[Bug lto/100010] [9/10/11/12 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.4                         |9.5

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9.4 is being released, retargeting bugs to GCC 9.5.

[Bug lto/100010] [9/10/11/12 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[xry111 at mengyan1223 dot wang]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

Xi Ruoyao <xry111 at mengyan1223 dot wang> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |xry111 at mengyan1223 dot wang

--- Comment #5 from Xi Ruoyao <xry111 at mengyan1223 dot wang> ---
Also breaks building texlive-20210325 with lto.

[Bug lto/100010] [10/11/12/13 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug lto/100010] [10/11/12/13 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug lto/100010] [10/11/12/13 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[yinyuefengyi at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

--- Comment #8 from Xionghu Luo (luoxhu at gcc dot gnu.org) <yinyuefengyi at gmail dot com> ---
At the ICE point, node->clone_of has value, but clone_of is NULL:

(gdb) p clone_of
$114 = (cgraph_node *) 0x0
(gdb) p node->clone_of
$115 = (cgraph_node *) 0x7ffff6664bb0
(gdb) pnode node->clone_of
_ZN12ErrorHandler8decorateERK6String/0 (decorate)
  Type: function
  Visibility: semantic_interposition virtual
  next sharing asm name: 0
  References:
  Referring:
  Availability: not_available
  Function flags:
  Called by:
  Calls:
(gdb) pnode node
_ZN12ErrorHandler8decorateERK6String/0 (decorate)
  Type: function definition analyzed
  Visibility: semantic_interposition virtual
  previous sharing asm name: 0
  References:
  Referring:
  Read from file: a-pr10010.o
  Function decorate/0 is inline copy in decorate/1
  Clone of _ZN12ErrorHandler8decorateERK6String/0
  Availability: local
  Unit id: 1
  Function flags: count:1073741824 (estimated locally) local
  Called by: _ZN20LandmarkErrorHandler8decorateERK6String/1 (inlined)
(1073741824 (estimated locally),1.00 per call)
  Calls: _ZN6StringD1Ev/37 (1073741824 (estimated locally),1.00 per call)
_ZN6StringC1Ec/38 (1073741824 (estimated loca
lly),1.00 per call) (can throw external)
   Polymorphic indirect call of type struct ErrorHandler token:0(1073741824
(estimated locally),1.00 per call) (can thr
ow external) of param:0 (vptr maybe changed) num speculative call targets: 0
    Outer type (dynamic):struct ErrorHandler (or a derived type) offset 0


This simple change could fix but not sure whether it is correct.

diff --git a/gcc/lto-cgraph.cc b/gcc/lto-cgraph.cc
index 6d9c36ea8b6..44a33a2af23 100644
--- a/gcc/lto-cgraph.cc
+++ b/gcc/lto-cgraph.cc
@@ -448,7 +448,7 @@ lto_output_node (struct lto_simple_output_block *ob, struct
cgraph_node *node,
   if (clone_of && !lto_symtab_encoder_encode_body_p (encoder,
ultimate_clone_of))
     clone_of = NULL;

-  if (tag == LTO_symtab_analyzed_node)
+  if (tag == LTO_symtab_analyzed_node && !flag_ltrans_devirtualize)
     gcc_assert (clone_of || !node->clone_of);
   if (!clone_of)
     streamer_write_hwi_stream (ob->main_stream, LCC_NOT_FOUND);

[Bug lto/100010] [11/12/13/14 Regression] ICE in lto_output_node, at lto-cgraph.c:447 (-fdevirtualize-at-ltrans) since r6-6384-gceda2c69d5219719

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100010

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.5

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.