posix/regcomp: initialize union structure tag to avoid warning

We see some surprising warnings on tilegx with gcc 4.8.2:

In file included from regex.c:66:0:
regcomp.c: In function ‘parse_expression’:
regcomp.c:2849:15: error: ‘end_elem’ may be used uninitialized in this
function [-Werror=maybe-uninitialized]
       else if (br_elem->type == COLL_SYM)
               ^
regcomp.c:3109:34: note: ‘end_elem’ was declared here
       bracket_elem_t start_elem, end_elem;
                                  ^
regcomp.c:3109:22: error: ‘start_elem’ may be used uninitialized in
this function [-Werror=maybe-uninitialized]
       bracket_elem_t start_elem, end_elem;
                      ^

These warnings are not seen on x86, and in fact if I compile the
preprocessed tile sources with the x86 gcc 4.8.2, I don't see the
warnings.  I do see eqiuvalent warnings if I compile the
x86-preprocessed source code with tilegx gcc 4.8.2.

The fix here is to initialize the union type field appropriately in
a couple of places where we pass a union pointer to a subroutine that
"knows" what type the union is.  Setting the type explicitly seems like
a more robust way to manage such a data structure in any case.

diff --git a/ChangeLog b/ChangeLog
index d147a0bde70a7573ea8359658cfb425f90240475..f5631c351b2bd97e6f01f3971345c4358c215431 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2015-01-07  Chris Metcalf  <cmetcalf@ezchip.com>
+
+       * posix/regcomp.c (parse_bracket_exp): Initialize type to
+       COLL_SYM in a couple of places to avoid uninitialized variable
+       wanings on tilegx gcc 4.8.2.
+
 2015-01-07  Richard Earnshaw  <rearnsha@arm.com>
 
        * sysdeps/aarch64/strcpy.S: New file.

diff --git a/posix/regcomp.c b/posix/regcomp.c
index 8e6d2f8cb5b3a28d3cb5ad72a7ea9815842342c4..fefbf67429535a692d18295fd04448b95b66adb9 100644 (file)
--- a/posix/regcomp.c
+++ b/posix/regcomp.c
@@ -3114,6 +3114,7 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
       re_token_t token2;
 
       start_elem.opr.name = start_name_buf;
+      start_elem.type = COLL_SYM;
       ret = parse_bracket_element (&start_elem, regexp, token, token_len, dfa,
                                   syntax, first_round);
       if (BE (ret != REG_NOERROR, 0))
@@ -3157,6 +3158,7 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
       if (is_range_exp == 1)
        {
          end_elem.opr.name = end_name_buf;
+         end_elem.type = COLL_SYM;
          ret = parse_bracket_element (&end_elem, regexp, &token2, token_len2,
                                       dfa, syntax, 1);
          if (BE (ret != REG_NOERROR, 0))