symtab/1677: [regression] selftest.exp, crash in lookup_symtab

[mec dot gnu at mindspring dot com]

>Number:         1677
>Category:       symtab
>Synopsis:       [regression] selftest.exp, crash in lookup_symtab
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jun 16 18:58:00 UTC 2004
>Closed-Date:
>Last-Modified:
>Originator:     mec.gnu@mindspring.com
>Release:        gdb HEAD 2004-06-13 05:30:11 UTC
>Organization:
>Environment:
native i686-pc-linux-gnu
red hat 8.0
gdb HEAD 2004-06-13 05:30:11 UTC
gdb compiled with gcc 3.3.2
dwarf-2
>Description:
gdb crashes in selftest.exp.

gdb.log excerpt:

  (gdb) PASS: gdb.base/selftest.exp: print a string
  step^M
  xmalloc (size=0) at /berman/fsf/_today_/source/gdb/HEAD/src/gdb/utils.c:1128^M
  1128      return xmmalloc (NULL, size);^M
  (gdb) PASS: gdb.base/selftest.exp: step into xmalloc call
  continue^M
  Continuing.^M
  FAIL: gdb.base/selftest.exp: (timeout) Set xgdb prompt

Stack trace:

  (gdb) bt 6
  #0  0x4207931a in strcmp () from /lib/i686/libc.so.6
  #1  0x080eb0ca in lookup_symtab (
      name=0xbfffe99c "/berman/fsf/_today_/source/gdb/HEAD/src/gdb/main.c")
      at /berman/fsf/_today_/source/gdb/HEAD/src/gdb/symtab.c:185
  #2  0x080f7ea3 in symtab_from_filename (argptr=0xbfffeaac,
      p=0x32 <Address 0x32 out of bounds>, is_quote_enclosed=0,
      not_found_ptr=0x0)
      at /berman/fsf/_today_/source/gdb/HEAD/src/gdb/linespec.c:1523
  #3  0x080f719b in decode_line_1 (argptr=0xbfffeaac, funfirstline=1,
      default_symtab=0x871a6d0, default_line=1128, canonical=0x0,
      not_found_ptr=0x0)
      at /berman/fsf/_today_/source/gdb/HEAD/src/gdb/linespec.c:744
  #4  0x080cebaa in breakpoint_re_set_one (bint=0x84dbd50)
      at /berman/fsf/_today_/source/gdb/HEAD/src/gdb/breakpoint.c:7149
  #5  0x0807f001 in do_catch_errors (uiout=0x82ced48, data=0x2f)
      at /berman/fsf/_today_/source/gdb/HEAD/src/gdb/top.c:524
  (More stack frames follow...)

Code fragment:

  (gdb) frame 1
  (gdb) list
  182         if (full_path != NULL)
  183           {
  184             const char *fp = symtab_to_fullname (s);
  185             if (FILENAME_CMP (full_path, fp) == 0)
  186               {
  187                 return s;
  188               }
  189           }

Data dump:

  (gdb) print *s
  $2 = {next = 0x8517dfc, blockvector = 0x851af74, linetable = 0x0,
    block_line_section = 11, primary = 1, macro_table = 0x0,
    filename = 0x851afc4 "version.c",
    dirname = 0x851afd8 "/berman/fsf/_today_/berman/build/target/native/gdb/HEAD
    line_charpos = 0x0, language = language_c,
    debugformat = 0x851b014 "DWARF 2", version = 0x0, fullname = 0x0,
    objfile = 0x82ef630}

Check it out.  s->fullname is NULL, so lookup_symtab barfs out when it calls FILENAME_CMP.

I suspect this patch, although it might be something else:

2004-06-10  Bob Rossi  <bob@brasko.net>

        * dbxread.c (read_dbx_symtab): Set pst->dirname when known.
        * dwarf2read.c (partial_die_info) : Add dirname field.
        (dwarf2_build_psymtabs_hard) : Set pst->dirname when known.
        (read_partial_die) : Save away DW_AT_comp_dir.
        * defs.h (symtab_to_filename) : Removed.
        * source.c (find_and_open_source) : Added.
        (open_source_file): Just calls find_and_open_source.
        (symtab_to_filename) : Removed.
        (symtab_to_fullname, psymtab_to_fullname ) : Added.
        * source.h (psymtab_to_fullname,symtab_to_fullname): Added.
        * symtab.c (lookup_symtab): Call symtab_to_fullname instead of
        symtab_to_filename.
        * symtab.h (partial_symtab): Add dirname field.
        * mi/mi-cmd-file.c (FILENAME,FULLNAME): Added.
        (mi_cmd_file_list_exec_source_file): Call new function symtab_to_fullnam
        to find fullname.
        (mi_cmd_file_list_exec_source_files): Added.
        * mi/mi-cmds.c (mi_cmd_mi_cmds) : Add -file-list-exec-source-files.
        * mi/mi-cmds.h (mi_cmd_file_list_exec_source_files): Added.

This regressed some time between gdb HEAD 2004-06-06 19:02:08 UTC and gdb HEAD 2004-06-13 05:30:11 UTC.  To be formal, it worked with gdb 6.1.



>How-To-Repeat:
Run selftest.exp.

I could do some work and trim this down to a much smaller test case if requested.
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: