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

[Asm warrior <asmwarrior@gmail.com>]

On 2011-6-14 0:59, Eli Zaretskii wrote:
>> Date: Mon, 13 Jun 2011 14:29:28 +0800
>> >  From: Asm warrior<asmwarrior@gmail.com>
>> >  CC: "John E. / TDM"<tdragon@tdragon.net>, Eli Zaretskii<eliz@gnu.org>,
>> >    jan.kratochvil@redhat.com,keiths@redhat.com
>> >
>> >  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.
> Because the function that canonicalizes the file name does not support
> backslashes correctly?
>

By reading the gdb source, mostly in file: source.c and symtab.c

I found that in the function:

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;
}

This function try to check if the file exists.

The lucky thing is: The function call:

open("D:\code\wxWidgets-2.8.12\build\msw/../../src/common/string.cpp") ;

works OK.

Though the file path is not satisfied by me, but it just satisfied by 
open() function, Yeah, the open() function can internally do a path 
canonization on its parameter, and gdb knows that this file exists and 
can be opened.

As I know, GDB does not do a canonization on any returned file names. (I 
can't find any code snippet doing this kind of work).

Well, the proposed method can be: (see below)
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);
       *******
       DoSomePathCanonization(&s->fullname);
       *******
       return s->fullname;
     }

   return NULL;
}

This way, the returned string can be:
"D:/code/wxWidgets-2.8.12/src/common/string.cpp"

BTW:Did you thing that Any one would like to set a breakpoint by using 
name containing many "../../"?

I can hardly think one would like to set a break point by entering this 
command:

b "D:\code\wxWidgets-2.8.12\build\msw/../../src/common/string.cpp:165"

I personally think this is too ugly.

Any ideas?

Asmwarrior
ollydbg from codeblocks' forum