[windows] patch to set breakpoint in a dll

[asmwarrior <asmwarrior@gmail.com>]

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Hi, all. Several months ago, I have propose and discuss this issue, but now I see no progress, so I just give a "Ping" like post.

The patch is quite simple. (see the attachment), currently, the patch is include in the MinGW's official gdb 7.4 release.

Why we need this patch? It can let us debug dll(the dll is build with relative file path under GCC)
The reason is below: this is my modified code

int
find_and_open_source (const char *filename,
		      const char *dirname,
		      char **fullname)
{
   char *path = source_path;
   const char *p;
   int result;
   char *lpath;

   /* Quick way out if we already know its full name.  */

   if (*fullname)
     {
       /* The user may have requested that source paths be rewritten
          according to substitution rules he provided.  If a substitution
          rule applies to this path, then apply it.  */
       char *rewritten_fullname = rewrite_source_path (*fullname);

       if (rewritten_fullname != NULL)
         {
           xfree (*fullname);
           *fullname = rewritten_fullname;
         }

       result = open (*fullname, OPEN_MODE);
       if (result >= 0)
       {
         lpath = gdb_realpath(*fullname);
         xfree(*fullname);
         *fullname = lpath;
         return result;
       }
       /* Didn't work -- free old one, try again.  */
       xfree (*fullname);
       *fullname = NULL;
     }

Here,
the *fullname = E:\code\cb\wx\wxWidgets-2.8.12\build\msw/../../src/common/string.cpp

And you set the break point by using this command:
break "E:/code/cb/wx/wxWidgets-2.8.12/src/common/string.cpp:164"
Without the patch, GDB can not set the breakpoint, no file name matches.

Luckily, the second break command works:
break E:\code\cb\wx\wxWidgets-2.8.12\build\msw/../../src/common/string.cpp:164
But I think no body will wrote such kind of file path specification.


Now, In my patch, I add a function "gdb_realpath" which internally use Windows API GetFullPathName() to calculate the canonized path. So, with this patch, the first break command works.

We have many discussion before:
http://sourceware.org/ml/gdb/2011-06/msg00074.html

Thanks.

Yuanhui Zhang
Codeblocks forum ID(ollydbg)











[-- Attachment #2: dll_bp.patch --]
[-- Type: text/x-patch, Size: 791 bytes --]

 gdb/source.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/gdb/source.c b/gdb/source.c
index cfdf81b..cd87e34 100644
--- a/gdb/source.c
+++ b/gdb/source.c
@@ -979,6 +979,7 @@ find_and_open_source (const char *filename,
   char *path = source_path;
   const char *p;
   int result;
+  char *lpath;
 
   /* Quick way out if we already know its full name.  */
 
@@ -997,7 +998,12 @@ find_and_open_source (const char *filename,
 
       result = open (*fullname, OPEN_MODE);
       if (result >= 0)
-	return result;
+      {
+        lpath = gdb_realpath(*fullname);
+        xfree(*fullname);
+        *fullname = lpath;
+        return result;
+      }
       /* Didn't work -- free old one, try again.  */
       xfree (*fullname);
       *fullname = NULL;