[Bug c++/53026] New: segfault in pt.c: lookup_template_class

[mattipee at yahoo dot co.uk]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53026

             Bug #: 53026
           Summary: segfault in pt.c: lookup_template_class
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mattipee@yahoo.co.uk


HEADLINE: pt.c:7595 - "Address 0x3 is not stack'd, malloc'd..."

user@host:~$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/i686-pc-linux-gnu/4.8.0/lto-wrapper
Target: i686-pc-linux-gnu
Configured with: ../gcc-svn/configure : (reconfigured) ../gcc-svn/configure :
(reconfigured) ../gcc-svn/configure
--enable-languages=c,c++,fortran,java,lto,objc --no-create --no-recursion :
(reconfigured) ../gcc-svn/configure --enable-languages=c++ : (reconfigured)
../gcc-svn/configure --enable-languages=c,c++,lto --no-create --no-recursion :
(reconfigured) ../gcc-svn/configure --enable-languages=c,c++,lto --no-create
--no-recursion : (reconfigured) ../gcc-svn/configure
--enable-languages=c,c++,lto --no-create --no-recursion
Thread model: posix
gcc version 4.8.0 20120417 (experimental) (GCC) 

(built, I believe, at revision 186523)

It would take some effort to construct minimal code to reproduce this segfault,
but the following details are available now...

user@host:~$ valgrind /path/to/cc1plus -std=c++11 -O2 -g0 -Wall ...
...
==18469==    at 0x81915D1: lookup_template_class(tree_node*, tree_node*,
tree_node*, tree_node*, int, int) (pt.c:7595)
==18469==    by 0x8194504: tsubst_aggr_type(tree_node*, tree_node*, int,
tree_node*, int) (pt.c:9876)
==18469==    by 0x819FB2A: tsubst(tree_node*, tree_node*, int, tree_node*)
(pt.c:11662)
==18469==    by 0x81B1E1E: tsubst_arg_types(tree_node*, tree_node*, int,
tree_node*) (pt.c:10844)
==18469==    by 0x81B1D04: tsubst_arg_types(tree_node*, tree_node*, int,
tree_node*) (pt.c:10814)
==18469==    by 0x81B219A: tsubst_function_type(tree_node*, tree_node*, int,
tree_node*) (pt.c:10940)
==18469==    by 0x819F676: tsubst(tree_node*, tree_node*, int, tree_node*)
(pt.c:11599)
==18469==    by 0x81A862D: tsubst_decl(tree_node*, tree_node*, int)
(pt.c:10247)
==18469==    by 0x81A01E4: tsubst(tree_node*, tree_node*, int, tree_node*)
(pt.c:11111)
==18469==    by 0x81AA6B4: tsubst_decl(tree_node*, tree_node*, int)
(pt.c:10094)
==18469==    by 0x81A01E4: tsubst(tree_node*, tree_node*, int, tree_node*)
(pt.c:11111)
==18469==    by 0x81D087F: instantiate_class_template(tree_node*) (pt.c:8935)
==18469==  Address 0x3 is not stack'd, malloc'd or (recently) free'd
==18469==