[Bug middle-end/52894] New: [4.5,4.6,4.7,4.8 Regression] Stage1 bootstrap fails with gcc-4.6.3: Infinite loop in pointer_set_insert

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52894

             Bug #: 52894
           Summary: [4.5,4.6,4.7,4.8 Regression] Stage1 bootstrap fails
                    with gcc-4.6.3: Infinite loop in pointer_set_insert
    Classification: Unclassified
           Product: gcc
           Version: 4.6.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: danglin@gcc.gnu.org
              Host: hppa-unknown-linux-gnu
            Target: hppa-unknown-linux-gnu
             Build: hppa-unknown-linux-gnu


Bootstrap fails with Debian gcc-4.6.3-2 and gcc-4.7.0-2.  The failure
was most likely caused by r185758 based on backtrace:

    PR middle-end/52640
    * varasm.c: Include pointer-set.h.
    (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.

gcc-4.6.3-1 and gcc-4.7.0-1 were ok.

The cause of the loop is as yet unclear but it is clearly not associated
with the above change.  The failure occurs compiling a number of files in
stage1.  It seems to be associated with the second vector allocation
in pointer_set_insert.

Triggered with the following options:

-fpreprocessed cgraphbuild.i -quiet -dumpbase cgraphbuild.c -auxbase-strip
cgraphbuild.o -g -Wextra -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual
-Wstrict-prototypes -Wmissing-prototypes -Wmissing-format-attribute -pedantic
-Wno-long-long -Wno-variadic-macros -Wno-overlength-strings
-Wold-style-definition -Wc++-compat -version -fkeep-inline-functions
-fno-common -o cgraphbuild.s