[Bug c++/32325] New: cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[Bug c++/32325] New: cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[gcc-bugzilla at gcc dot gnu dot org]

During a mainline bootstrap on alpha-dec-osf5.1b, the libstdc++ configure
failed:

checking for exception model to use... configure: error: unable to detect
exception model
make[1]: *** [configure-target-libstdc++-v3] Error 1

config.log reveals:

configure:13794: checking for exception model to use
configure:13838:  /vol/gccsrc/obj/gcc-4.3.0-20070612/5.1b-gcc/./gcc/xgcc
-shared-libgcc -B/vol/gccsrc/obj/gcc-4.3.0-20070612/5.1b-gcc/./gcc -nostdinc++
-L/vol/gccsrc/obj/gcc-4.3.0-20070612/5.1b-gcc/alpha-dec-osf5.1b/libstdc++-v3/src
-L/vol/gccsrc/obj/gcc-4.3.0-20070612/5.1b-gcc/alpha-dec-osf5.1b/libstdc++-v3/src/.libs
-B/vol/gcc/alpha-dec-osf5.1b/bin/ -B/vol/gcc/alpha-dec-osf5.1b/lib/ -isystem
/vol/gcc/alpha-dec-osf5.1b/include -isystem
/vol/gcc/alpha-dec-osf5.1b/sys-include -c -S  conftest.cc >&5
configure: In function 'void foo()':
configure:13836: error: end insn 27 for block 7 not found in the insn stream
configure:13836: error: head insn 24 for block 7 not found in the insn stream
configure:13836: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
configure:13841: $? = 1
configure:13870: error: unable to detect exception model

This happens with the following conftest.cc:

struct S { ~S(); };
void bar();
void foo()
{
  S s;
  bar();
}

 % ./cc1plus conftest.cc
 void foo()
Analyzing compilation unit
Performing interprocedural optimizations
 <visibility> <early_local_cleanups> <inline>Assembling functions:
 void foo()
conftest.cc: In function 'void foo()':
conftest.cc:7: error: end insn 27 for block 7 not found in the insn stream
conftest.cc:7: error: head insn 24 for block 7 not found in the insn stream
conftest.cc:7: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

Running gdb reveals

Program received signal SIGSEGV, Segmentation fault.
rtl_verify_flow_info () at /vol/gcc/src/gcc-dist/gcc/cfgrtl.c:2005
(gdb) where
#0  rtl_verify_flow_info () at /vol/gcc/src/gcc-dist/gcc/cfgrtl.c:2005
#1  0x0000000120516638 in verify_flow_info () at
/vol/gcc/src/gcc-dist/gcc/cfghooks.c:245
#2  0x0000000120618934 in commit_edge_insertions () at
/vol/gcc/src/gcc-dist/gcc/cfgrtl.c:1467
#3  0x0000000120415bcc in alpha_gp_save_rtx () at
/vol/gcc/src/gcc-dist/gcc/config/alpha/alpha.c:4784
#4  0x00000001206406fc in gen_exception_receiver () at
/vol/gcc/src/gcc-dist/gcc/config/alpha/alpha.md:7019
#5  0x0000000120314dc8 in finish_eh_generation () at
/vol/gcc/src/gcc-dist/gcc/except.c:1633
#6  0x0000000120314f98 in rest_of_handle_eh () at
/vol/gcc/src/gcc-dist/gcc/except.c:3985
#7  0x0000000120421978 in execute_one_pass (pass=0x0) at
/vol/gcc/src/gcc-dist/gcc/passes.c:1124
#8  0x0000000120421c48 in execute_pass_list (pass=0x0) at
/vol/gcc/src/gcc-dist/gcc/passes.c:1177
#9  0x0000000120421c5c in execute_pass_list (pass=0x0) at
/vol/gcc/src/gcc-dist/gcc/passes.c:1178
#10 0x00000001204fef44 in tree_rest_of_compilation (fndecl=0x0) at
/vol/gcc/src/gcc-dist/gcc/tree-optimize.c:406
#11 0x00000001202535c8 in c_expand_body (fndecl=0x140137d80) at
/vol/gcc/src/gcc-dist/gcc/c-common.c:4331
#12 0x00000001201ea958 in expand_body (fn=0x18de60) at
/vol/gcc/src/gcc-dist/gcc/cp/semantics.c:3136
#13 0x0000000120423f60 in cgraph_expand_function (node=0x18de60) at
/vol/gcc/src/gcc-dist/gcc/cgraphunit.c:1073
#14 0x0000000120427400 in cgraph_optimize () at
/vol/gcc/src/gcc-dist/gcc/cgraphunit.c:1142
#15 0x000000012015e054 in cp_write_global_declarations () at
/vol/gcc/src/gcc-dist/gcc/cp/decl2.c:3305
#16 0x00000001204432e0 in toplev_main (argc=1, argv=0x0) at
/vol/gcc/src/gcc-dist/gcc/toplev.c:1064
#17 0x000000012029fe98 in main (argc=1075019136, argv=0x11fffbb30) at
/vol/gcc/src/gcc-dist/gcc/main.c:35
(gdb) p x
$1 = 0x0

I.e. rtl_verify_flow_info dereferences a NULL pointer.  This happens only
on alpha-dec-osf5.1b, alpha-dec-osf4.0f is unaffected.

Environment:
System: OSF1 bartok V5.1 2650 alpha
Machine: alpha

host: alpha-dec-osf5.1b
build: alpha-dec-osf5.1b
target: alpha-dec-osf5.1b
configured with: /vol/gcc/src/gcc-dist/configure --prefix=/vol/gcc
--with-local-prefix=/vol/gcc --disable-nls --host alpha-dec-osf5.1b --build
alpha-dec-osf5.1b --target alpha-dec-osf5.1b --with-gmp=/vol/gcc
--with-mpfr=/vol/gcc --enable-languages=c,c++,fortran,java,objc,ada
--disable-libmudflap

How-To-Repeat:
Bootstrap as described above.


-- 
           Summary: cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B:
                    SEGV in rtl_verify_flow_info
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ro at techfak dot uni-bielefeld dot de
 GCC build triplet: alpha-dec-osf5.1b
  GCC host triplet: alpha-dec-osf5.1b
GCC target triplet: alpha-dec-osf5.1b


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32325

[Bug target/32325] [4.3 Regression] cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal
          Component|c++                         |target
           Keywords|                            |build, ice-on-valid-code
            Summary|cc1plus ICE configuring     |[4.3 Regression] cc1plus ICE
                   |libstdc++ on Tru64 UNIX     |configuring libstdc++ on
                   |V5.1B: SEGV in              |Tru64 UNIX V5.1B: SEGV in
                   |rtl_verify_flow_info        |rtl_verify_flow_info
   Target Milestone|---                         |4.3.0
            Version|unknown                     |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32325

[Bug target/32325] [4.3 Regression] cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[ro at techfak dot uni-bielefeld dot de]

------- Comment #1 from ro at techfak dot uni-bielefeld dot de  2007-09-20 14:17 -------
Subject: Re:  [4.3 Regression] cc1plus ICE configuring libstdc++ on Tru64 UNIX
V5.1B: SEGV in rtl_verify_flow_info

A reghunt revealed that this was caused by the following patch:

2007-03-02  Eric Botcazou  <ebotcazou@adacore.com>

        * config/alpha/alpha.c (alpha_gp_save_rtx): Insert the insns at the
        entry by means of emit_insn_at_entry.

Since alpha_gp_save_rtx is only used with TARGET_LD_BUGGY_LDGP, which is
only defined in osf5.h, alpha-dec-osf5.1b is affected while
alpha-dec-osf4.0f is not.

        Rainer


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32325

[Bug target/32325] [4.3 Regression] cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[ebotcazou at gcc dot gnu dot org]

------- Comment #2 from ebotcazou at gcc dot gnu dot org  2007-09-20 20:45 -------
> A reghunt revealed that this was caused by the following patch:
> 
> 2007-03-02  Eric Botcazou  <ebotcazou@adacore.com>
> 
>         * config/alpha/alpha.c (alpha_gp_save_rtx): Insert the insns at the
>         entry by means of emit_insn_at_entry.

Right.  Interestingly enough, this is purely a checking failure, i.e. the IL
is correct at the end of the pass.  What happens is that in

  if (USING_SJLJ_EXCEPTIONS)
    sjlj_build_landing_pads ();
  else
    dw2_build_landing_pads ();

  cfun->eh->built_landing_pads = 1;

  /* We've totally changed the CFG.  Start over.  */
  find_exception_handler_labels ();
  break_superblocks ();
  if (USING_SJLJ_EXCEPTIONS)
    commit_edge_insertions ();

dw2_build_landing_pads will trigger a CFG verification, which of course is
not the right thing to do given the comment in the code.

The solution is the original patch I posted:
  http://gcc.gnu.org/ml/gcc-patches/2006-11/msg01448.html
which was OKed by RTH:
  http://gcc.gnu.org/ml/gcc-patches/2007-02/msg01162.html
so I'm going to apply it.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32325

[Bug target/32325] [4.3 Regression] cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[ebotcazou at gcc dot gnu dot org]

------- Comment #3 from ebotcazou at gcc dot gnu dot org  2007-09-20 20:46 -------
Fixing.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |ebotcazou at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-09-20 20:46:14
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32325

[Bug target/32325] [4.3 Regression] cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[ebotcazou at gcc dot gnu dot org]

------- Comment #4 from ebotcazou at gcc dot gnu dot org  2007-09-20 20:48 -------
Btw, Rainer, would you know whether TARGET_LD_BUGGY_LDGP is still relevant?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32325

[Bug target/32325] [4.3 Regression] cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[ebotcazou at gcc dot gnu dot org]

------- Comment #5 from ebotcazou at gcc dot gnu dot org  2007-09-22 08:43 -------
Subject: Bug 32325

Author: ebotcazou
Date: Sat Sep 22 08:42:57 2007
New Revision: 128665

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=128665
Log:
        PR target/32325
        * except.c (finish_eh_generation): Call commit_edge_insertions if
        there are insns queued on the entry edge.
        * config/alpha/alpha.c (alpha_gp_save_rtx): Insert the insns on
        the entry edge.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/alpha/alpha.c
    trunk/gcc/except.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32325

[Bug target/32325] [4.3 Regression] cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[ebotcazou at gcc dot gnu dot org]

------- Comment #6 from ebotcazou at gcc dot gnu dot org  2007-09-22 08:46 -------
Note that libstdc++-v3 didn't build for me without a kludge for EOVERFLOW.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32325

[Bug target/32325] [4.3 Regression] cc1plus ICE configuring libstdc++ on Tru64 UNIX V5.1B: SEGV in rtl_verify_flow_info

[roger at eyesopen dot com]

------- Comment #7 from roger at eyesopen dot com  2007-10-13 04:14 -------
*** Bug 33545 has been marked as a duplicate of this bug. ***


-- 

roger at eyesopen dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |roger at eyesopen dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32325