[Bug ipa/65432] New: [5 Regression] Invalid read of size 1: ipa_icf::sem_item_optimizer::merge_classes(unsigned int) (ipa-icf.c:2958)

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65432

            Bug ID: 65432
           Summary: [5 Regression] Invalid read of size 1:
                    ipa_icf::sem_item_optimizer::merge_classes(unsigned
                    int) (ipa-icf.c:2958)
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org

Running the testsuite on ppc64le with an --enable-checking=valgrind
compiler shows many instances of:

==94166== Invalid read of size 1
==94166==    at 0x40980F8: strlen (in
/usr/lib64/valgrind/vgpreload_memcheck-ppc64le-linux.so)
==94166==    by 0x4626503: vfprintf@@GLIBC_2.17 (in /usr/lib64/libc-2.20.so)
==94166==    by 0x4631003: fprintf@@GLIBC_2.17 (in /usr/lib64/libc-2.20.so)
==94166==    by 0x10CF34B3: ipa_icf::sem_item_optimizer::merge_classes(unsigned
int) (ipa-icf.c:2958)
==94166==    by 0x10CF962B: ipa_icf::sem_item_optimizer::execute()
(ipa-icf.c:2236)
==94166==    by 0x10CFC8DF: ipa_icf_driver (ipa-icf.c:3060)
==94166==    by 0x10CFC8DF: ipa_icf::pass_ipa_icf::execute(function*)
(ipa-icf.c:3107)
==94166==    by 0x1068FBC7: execute_one_pass(opt_pass*) (passes.c:2328)
==94166==    by 0x10690B53: execute_ipa_pass_list(opt_pass*) (passes.c:2727)
==94166==    by 0x1038D2DF: ipa_passes (cgraphunit.c:2207)
==94166==    by 0x1038D2DF: symbol_table::compile() (cgraphunit.c:2295)
==94166==    by 0x1038ED47: symbol_table::finalize_compilation_unit()
(cgraphunit.c:2444)
==94166==    by 0x101A31CB: cp_write_global_declarations() (decl2.c:4754)
==94166==    by 0x1076894F: compile_file() (toplev.c:608)
==94166==  Address 0x701ee20 is 0 bytes inside a block of size 38 free'd
==94166==    at 0x4095394: free (in
/usr/lib64/valgrind/vgpreload_memcheck-ppc64le-linux.so)
==94166==    by 0x10243CAF: cxx_printable_name_internal(tree_node*, int, bool)
(tree.c:2026)
==94166==    by 0x10374D23: symtab_node::name() const (symtab.c:479)
==94166==    by 0x10CF3497: name (ipa-icf.h:177)
==94166==    by 0x10CF3497: ipa_icf::sem_item_optimizer::merge_classes(unsigned
int) (ipa-icf.c:2958)
==94166==    by 0x10CF962B: ipa_icf::sem_item_optimizer::execute()
(ipa-icf.c:2236)
==94166==    by 0x10CFC8DF: ipa_icf_driver (ipa-icf.c:3060)
==94166==    by 0x10CFC8DF: ipa_icf::pass_ipa_icf::execute(function*)
(ipa-icf.c:3107)
==94166==    by 0x1068FBC7: execute_one_pass(opt_pass*) (passes.c:2328)
==94166==    by 0x10690B53: execute_ipa_pass_list(opt_pass*) (passes.c:2727)
==94166==    by 0x1038D2DF: ipa_passes (cgraphunit.c:2207)
==94166==    by 0x1038D2DF: symbol_table::compile() (cgraphunit.c:2295)
==94166==    by 0x1038ED47: symbol_table::finalize_compilation_unit()
(cgraphunit.c:2444)
==94166==    by 0x101A31CB: cp_write_global_declarations() (decl2.c:4754)
==94166==    by 0x1076894F: compile_file() (toplev.c:608)