etags.c segv
On my Solaris 5.8 machines here at work, when running 'make TAGS' with
a 21.4.16 build, I'm getting a segv running etags.
Here's the backtrace:
#0 0x00021ba4 in regex_compile (
pattern=0xffbefada "[ \t]*DEF\\(VAR\\|INE\\)_[A-Z_]+[ \t]*([
\t]*\"\\([^\"]+\\)\"", size=50,
syntax=512, bufp=0x45ea8) at /u/sheltonv/software/src/xemacs-21.4.16/src/regex.c:2008
#1 0x0002fa10 in re_compile_pattern (
pattern=0xffbefada "[ \t]*DEF\\(VAR\\|INE\\)_[A-Z_]+[ \t]*([
\t]*\"\\([^\"]+\\)\"", length=50,
bufp=0x45ea8) at /u/sheltonv/software/src/xemacs-21.4.16/src/regex.c:6251
#2 0x0001e5b4 in add_regex (
regexp_pattern=0xffbefada "[ \t]*DEF\\(VAR\\|INE\\)_[A-Z_]+[ \t]*([
\t]*\"\\([^\"]+\\)\"",
ignore_case=0, lang=0x0) at
/u/sheltonv/software/src/xemacs-21.4.16/lib-src/etags.c:5175
#3 0x0001e458 in analyse_regex (
regex_arg=0xffbefada "[ \t]*DEF\\(VAR\\|INE\\)_[A-Z_]+[ \t]*([
\t]*\"\\([^\"]+\\)\"",
ignore_case=0) at /u/sheltonv/software/src/xemacs-21.4.16/lib-src/etags.c:5136
#4 0x000127e4 in main (argc=5, argv=0xffbef974)
at /u/sheltonv/software/src/xemacs-21.4.16/lib-src/etags.c:1133
Here's what I found:
(gdb) p bufp
$3 = (struct re_pattern_buffer *) 0x45ea8
(gdb) p *bufp
$4 = {buffer = 0x0, allocated = 0, used = 0, syntax = 512, fastmap = 0x0, translate = 0x0,
re_nsub = 0, re_ngroups = 0, can_be_null = 0, regs_allocated = 0, fastmap_accurate = 0,
no_sub = 0, not_bol = 0, not_eol = 0, newline_anchor = 1,
external_to_internal_register = 0x75736572, external_to_internal_register_size =
286368}
(The values for both external_to_internal_register and
external_to_internal_register_size looked potentially suspicious to me
- bufp was newly allocated in add_regex just before the call to
re_compile_pattern.)
In regex.c, at line 2004, there's the following check:
if (bufp->external_to_internal_register == 0)
{
bufp->external_to_internal_register_size = INIT_REG_TRANSLATE_SIZE;
RETALLOC (bufp->external_to_internal_register,
bufp->external_to_internal_register_size,
int);
}
So, I set external_to_internal_register to 0 and the crash went away.
Patch included here:
--- xemacs-21.4.16/lib-src/etags.c 2004-06-24 00:02:29.000000000 -0400
+++ xemacs-21.4.16/lib-src/etags.c-works 2004-12-16 15:44:56.109304000 -0500
＠＠ -5171,6 +5171,7 ＠＠
patbuf->fastmap = NULL;
patbuf->buffer = NULL;
patbuf->allocated = 0;
+ patbuf->external_to_internal_register = 0;
err = re_compile_pattern (regexp_pattern, strlen (regexp_pattern), patbuf);
if (err != NULL)
But, this can't be right, can it? patbuf is allocated in etags.c and
it looks like it's not fully initialized, but if this fix is right,
how could the code ever have worked?
Thanks for any help you can offer,
Vin
--
In a minute there is time
For decisions and revisions which a minute will reverse. T.S. Eliot
[URL: http://www.cs.amherst.edu/~ccm/prufrock.html]