[Bug c/79684] New: Conditional jump or move depends on uninitialised value in GIMPLE FE

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79684

            Bug ID: 79684
           Summary: Conditional jump or move depends on uninitialised
                    value in GIMPLE FE
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: dmalcolm at gcc dot gnu.org, rguenth at gcc dot gnu.org
  Target Milestone: ---

Hello.

Starting from r244434, I see:
valgrind --leak-check=yes --trace-children=yes ./xgcc -B.
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/tree-ssa/scev-3.c -c

==18764== Conditional jump or move depends on uninitialised value(s)
==18764==    at 0x142888B: can_be_stored_compactly_p (line-map.c:144)
==18764==    by 0x142888B: get_combined_adhoc_loc(line_maps*, unsigned int,
source_range, void*) (line-map.c:186)
==18764==    by 0xEBAC2F: COMBINE_LOCATION_DATA (line-map.h:1020)
==18764==    by 0xEBAC2F: set_source_range(tree_node*, source_range)
(tree.c:14380)
==18764==    by 0xEBAC81: set_source_range(tree_node*, unsigned int, unsigned
int) (tree.c:14370)
==18764==    by 0x6ED7DA: c_parser_gimple_postfix_expression_after_primary
(gimple-parser.c:977)
==18764==    by 0x6ED7DA: c_parser_gimple_postfix_expression(c_parser*)
(gimple-parser.c:942)
==18764==    by 0x6EE4AA: c_parser_gimple_unary_expression(c_parser*)
(gimple-parser.c:624)
==18764==    by 0x6EEE91: c_parser_gimple_statement (gimple-parser.c:271)
==18764==    by 0x6EEE91: c_parser_gimple_compound_statement
(gimple-parser.c:226)
==18764==    by 0x6EEE91: c_parser_parse_gimple_body(c_parser*)
(gimple-parser.c:92)
==18764==    by 0x6D7E55: c_parser_declaration_or_fndef(c_parser*, bool, bool,
bool, bool, bool, tree_node**, vec<c_token, va_heap, vl_ptr>,
oacc_routine_data*, bool*) (c-parser.c:2091)
==18764==    by 0x6DFD5B: c_parser_external_declaration(c_parser*)
(c-parser.c:1468)
==18764==    by 0x6E07B9: c_parser_translation_unit (c-parser.c:1348)
==18764==    by 0x6E07B9: c_parse_file() (c-parser.c:18195)
==18764==    by 0x73EDC2: c_common_parse_file() (c-opts.c:1107)
==18764==    by 0xBFFDCE: compile_file() (toplev.c:467)
==18764==    by 0x654106: do_compile (toplev.c:1984)
==18764==    by 0x654106: toplev::main(int, char**) (toplev.c:2118)

Thanks