Re: setting a breakpoint on a dll, relative path or absolute path issue

[Asm warrior <asmwarrior@gmail.com>]

I just go a little further, and found that there is a function to look 
up a file name in symbol tables.

struct symtab * lookup_symtab (const char *name)

the parameter name is the user supplied file name string to set a 
breakpoint.

This function will loop all the symbols and do a string match.

symtab_to_fullname() is used to read symbol's filename, it was defined 
in the gdb/source.c line 1110


char *
symtab_to_fullname (struct symtab *s)
{
   int r;

   if (!s)
     return NULL;

   /* Don't check s->fullname here, the file could have been
      deleted/moved/..., look for it again.  */
   r = find_and_open_source (s->filename, s->dirname, &s->fullname);

   if (r >= 0)
     {
       close (r);
       return s->fullname;
     }

   return NULL;
}

When loop on the symbols. I found that at one loop, I get

s->filename = "../../src/common/string.cpp"
s->dirname  = "D:\code\wxWidgets-2.8.12\build\msw"

But too badly, the result
s->fullname = 
"D:\code\wxWidgets-2.8.12\build\msw/../../src/common/string.cpp"

This is the reason about the issue, if the result is:
"D:\code\wxWidgets-2.8.12/src/common/string.cpp"
Then, this problem can be fixed.

I'm not sure why gdb does not give a cannical filename, but still leaves 
the "../../" in the result.



By the way, gdb's matching algorithm care both "/" and "\" as equivalent 
char under Windows.

Look at here: gdb\libiberty\filename_cmp.c

int
filename_cmp (const char *s1, const char *s2)
{
#ifndef HAVE_DOS_BASED_FILE_SYSTEM
  return strcmp(s1, s2);
#else
  for (;;)
     {
      int c1 = TOLOWER (*s1);
      int c2 = TOLOWER (*s2);

      /* On DOS-based file systems, the '/' and the '\' are equivalent.  */
      if (c1 == '/')
        c1 = '\\';
      if (c2 == '/')
        c2 = '\\';

      if (c1 != c2)
        return (c1 - c2);

      if (c1 == '\0')
        return 0;

      s1++;
      s2++;
     }
#endif
}


Asmwarrior
ollydbg from codeblocks' forum