[Bug middle-end/55709] New: [4.8 Regression] Infinite loop in pointer_set_insert compiling cp/pt.c

["danglin at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55709

             Bug #: 55709
           Summary: [4.8 Regression] Infinite loop in pointer_set_insert
                    compiling cp/pt.c
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: danglin@gcc.gnu.org
                CC: jakub@gcc.gnu.org, steven@gcc.gnu.org
              Host: hppa-unknown-linux-gnu
            Target: hppa-unknown-linux-gnu
             Build: hppa-unknown-linux-gnu


Created attachment 28978
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28978
Compressed preprocessed sourcce

Hang occurs in stage2 here:

/home/dave/gnu/gcc/objdir/./prev-gcc/xg++
-B/home/dave/gnu/gcc/objdir/./prev-gcc/
-B/home/dave/opt/gnu/gcc/gcc-4.8/hppa-linux-gnu/bin/ -nostdinc++
-B/home/dave/gnu/gcc/objdir/prev-hppa-linux-gnu/libstdc++-v3/src/.libs
-B/home/dave/gnu/gcc/objdir/prev-hppa-linux-gnu/libstdc++-v3/libsupc++/.libs
-I/home/dave/gnu/gcc/objdir/prev-hppa-linux-gnu/libstdc++-v3/include/hppa-linux-gnu
-I/home/dave/gnu/gcc/objdir/prev-hppa-linux-gnu/libstdc++-v3/include
-I/home/dave/gnu/gcc/gcc/libstdc++-v3/libsupc++
-L/home/dave/gnu/gcc/objdir/prev-hppa-linux-gnu/libstdc++-v3/src/.libs
-L/home/dave/gnu/gcc/objdir/prev-hppa-linux-gnu/libstdc++-v3/libsupc++/.libs -c
 -DIN_GCC_FRONTEND -DIN_GCC_FRONTEND -g -O2 -DIN_GCC   -fno-exceptions
-fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings
-Wcast-qual -Wmissing-format-attribute -pedantic -Wno-long-long
-Wno-variadic-macros -Wno-overlength-strings -Werror -fno-common 
-DHAVE_CONFIG_H -I. -Icp -I../../gcc/gcc -I../../gcc/gcc/cp
-I../../gcc/gcc/../include -I../../gcc/gcc/../libcpp/include 
-I../../gcc/gcc/../libdecnumber -I../../gcc/gcc/../libdecnumber/dpd
-I../libdecnumber -I../../gcc/gcc/../libbacktrace    ../../gcc/gcc/cp/pt.c -o
cp/pt.o

(gdb) bt
#0  0x006a88a4 in insert_aux (log_slots=1, n_slots=4096, slots=0x15659c0, 
    p=0x3b579) at ../../gcc/gcc/pointer-set.c:123
#1  pointer_set_insert (pset=0xe06f20, p=0x4309cf80)
    at ../../gcc/gcc/pointer-set.c:153
#2  0x009d3dcc in assemble_external (decl=0x4309cf80)
    at ../../gcc/gcc/varasm.c:2199
#3  0x004e0608 in output_addr_const (file=0xe05a20, x=0x4421d090)
    at ../../gcc/gcc/final.c:3701
#4  0x009eb3ac in pa_assemble_integer (x=0x4421d090, size=<optimized out>, 
    aligned_p=1) at ../../gcc/gcc/config/pa/pa.c:3221
#5  0x009d476c in assemble_integer (x=0x4421d090, size=4, align=32, force=1)
    at ../../gcc/gcc/varasm.c:2496
#6  0x009eb208 in output_deferred_plabels ()
    at ../../gcc/gcc/config/pa/pa.c:5611
#7  0x0076b588 in compile_file () at ../../gcc/gcc/toplev.c:670
#8  0x0076d4ec in do_compile () at ../../gcc/gcc/toplev.c:1878
#9  toplev_main (argc=73, argv=0xfc1c002c) at ../../gcc/gcc/toplev.c:1954
#10 0x00b32bdc in main (argc=<optimized out>, argv=<optimized out>)
    at ../../gcc/gcc/main.c:36

This was introduced by:

2012-12-12  Steven Bosscher  <steven@gcc.gnu.org>
            Jakub Jelinek  <jakub@redhat.com>

        PR middle-end/52640
        * varasm.c (pending_assemble_externals_set): New pointer set.
        (process_pending_assemble_externals): Destroy the pointer set.
        (assemble_external): See if decl is in pending_assemble_externals_set,
        and add it to pending_assemble_externals if necessary.
        (init_varasm_once): Allocate pending_assemble_externals_set.

Think pending_assemble_externals_set has been destroyed when this happens.

This came up before which was why the above change wasn't installed on trunk.
See PR middle-end/52894.  Thought Steven was going to try to come up with
something better for trunk.

cc1plus options:
-fpreprocessed pt.ii -quiet -dumpbase pt.c -auxbase-strip cp/pt.o -g -O2
-Wextra -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual
-Wsuggest-attribute=format -Wpedantic -Wno-long-long -Wno-variadic-macros
-Wno-overlength-strings -Werror -version -fno-exceptions -fno-rtti
-fasynchronous-unwind-tables -fno-common -o pt.s