[patch] Fix some plugin API issues in BFD

[patch] Fix some plugin API issues in BFD

[Rafael Ávila de Espíndola]

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I recently updated a plugin to use the file descriptor directly. This 
worked fine in gold, but had two issues using bfd (nm and ar):

*) The filesize was not being set.
*) The code expected the claim_file callback to not seek.

That is not my understanding from reading the api documentation in 
http://gcc.gnu.org/wiki/whopr/driver, so the attached patch fixes both 
issues.

2010-02-08  Rafael Ávila de Espíndola <respindola@mozilla.com>

	* plugin.c (bfd_plugin_object_p): Correctly set the filesize
	and handle claim_file seeking.

Cheers,
Rafael

[-- Attachment #2: bfd.patch --]
[-- Type: text/x-patch, Size: 799 bytes --]

diff --git a/bfd/plugin.c b/bfd/plugin.c
index 30a4923..319ef50 100644
--- a/bfd/plugin.c
+++ b/bfd/plugin.c
@@ -251,7 +251,7 @@ bfd_plugin_object_p (bfd *abfd)
     {
       iobfd = abfd;
       file.offset = 0;
-      file.filesize = 0; /*FIXME*/
+      file.filesize = 0;
     }
 
   if (!iobfd->iostream && !bfd_open_file (iobfd))
@@ -259,8 +259,18 @@ bfd_plugin_object_p (bfd *abfd)
 
   file.fd = fileno ((FILE *) iobfd->iostream);
 
+  if (!abfd->my_archive)
+    {
+      struct stat stat_buf;
+      if (fstat (file.fd, &stat_buf))
+        return NULL;
+      file.filesize = stat_buf.st_size;
+    }
+
   file.handle = abfd;
+  off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
   claim_file (&file, &claimed);
+  lseek(file.fd, cur_offset, SEEK_SET);
   if (!claimed)
     return NULL;
 

Re: [patch] Fix some plugin API issues in BFD

[Rafael Avila de Espindola]

ccing Dave and Cary.

On 11-02-08 10:17 PM, Rafael Ávila de Espíndola wrote:
> I recently updated a plugin to use the file descriptor directly. This
> worked fine in gold, but had two issues using bfd (nm and ar):
>
> *) The filesize was not being set.
> *) The code expected the claim_file callback to not seek.
>
> That is not my understanding from reading the api documentation in
> http://gcc.gnu.org/wiki/whopr/driver, so the attached patch fixes both
> issues.
>
> 2010-02-08 Rafael Ávila de Espíndola <respindola@mozilla.com>
>
> * plugin.c (bfd_plugin_object_p): Correctly set the filesize
> and handle claim_file seeking.

Cheers,
Rafael

Re: [patch] Fix some plugin API issues in BFD

[Rafael Ávila de Espíndola]

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An updated patch is attached that also avoids calling onload multiple times.

2010-02-20  Rafael Ávila de Espíndola <respindola@mozilla.com>

        * plugin.c (bfd_plugin_object_p): Correctly set the filesize
	and handle claim_file seeking. Only try to load the plugin once.

On 2011-02-08 22:17, Rafael Ávila de Espíndola wrote:
> I recently updated a plugin to use the file descriptor directly. This
> worked fine in gold, but had two issues using bfd (nm and ar):
> 
> *) The filesize was not being set.
> *) The code expected the claim_file callback to not seek.
> 
> That is not my understanding from reading the api documentation in
> http://gcc.gnu.org/wiki/whopr/driver, so the attached patch fixes both
> issues.

Cheers,
Rafael

[-- Attachment #2: bfd.patch --]
[-- Type: text/x-patch, Size: 1371 bytes --]

diff --git a/bfd/plugin.c b/bfd/plugin.c
index 30a4923..224d0e2 100644
--- a/bfd/plugin.c
+++ b/bfd/plugin.c
@@ -232,16 +232,21 @@ static const bfd_target *
 bfd_plugin_object_p (bfd *abfd)
 {
   int claimed = 0;
-  int t = load_plugin ();
   struct ld_plugin_input_file file;
   bfd *iobfd;
-
-  if (!t)
+  static int have_loaded = 0;
+  static int have_plugin = 0;
+  if (!have_loaded)
+    {
+      have_loaded = 1;
+      have_plugin = load_plugin ();
+    }
+  if (!have_plugin)
     return NULL;
 
   file.name = abfd->filename;
 
-  if (abfd->my_archive)
+  if (abfd->format == bfd_archive)
     {
       iobfd = abfd->my_archive;
       file.offset = abfd->origin;
@@ -251,7 +256,7 @@ bfd_plugin_object_p (bfd *abfd)
     {
       iobfd = abfd;
       file.offset = 0;
-      file.filesize = 0; /*FIXME*/
+      file.filesize = 0;
     }
 
   if (!iobfd->iostream && !bfd_open_file (iobfd))
@@ -259,8 +264,18 @@ bfd_plugin_object_p (bfd *abfd)
 
   file.fd = fileno ((FILE *) iobfd->iostream);
 
+  if (abfd->format == bfd_object)
+    {
+      struct stat stat_buf;
+      if (fstat (file.fd, &stat_buf))
+        return NULL;
+      file.filesize = stat_buf.st_size;
+    }
+
   file.handle = abfd;
+  off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
   claim_file (&file, &claimed);
+  lseek(file.fd, cur_offset, SEEK_SET);
   if (!claimed)
     return NULL;
 

Re: [patch] Fix some plugin API issues in BFD

[Rafael Ávila de Espíndola]

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On 2011-02-20 14:54, Rafael Ávila de Espíndola wrote:
> An updated patch is attached that also avoids calling onload multiple times.

Sorry, the correct one is now attached.

Cheers,
Rafael

[-- Attachment #2: bfd.patch --]
[-- Type: text/x-patch, Size: 1224 bytes --]

diff --git a/bfd/plugin.c b/bfd/plugin.c
index 30a4923..bba9548 100644
--- a/bfd/plugin.c
+++ b/bfd/plugin.c
@@ -232,11 +232,16 @@ static const bfd_target *
 bfd_plugin_object_p (bfd *abfd)
 {
   int claimed = 0;
-  int t = load_plugin ();
   struct ld_plugin_input_file file;
   bfd *iobfd;
-
-  if (!t)
+  static int have_loaded = 0;
+  static int have_plugin = 0;
+  if (!have_loaded)
+    {
+      have_loaded = 1;
+      have_plugin = load_plugin ();
+    }
+  if (!have_plugin)
     return NULL;
 
   file.name = abfd->filename;
@@ -251,7 +256,7 @@ bfd_plugin_object_p (bfd *abfd)
     {
       iobfd = abfd;
       file.offset = 0;
-      file.filesize = 0; /*FIXME*/
+      file.filesize = 0;
     }
 
   if (!iobfd->iostream && !bfd_open_file (iobfd))
@@ -259,8 +264,18 @@ bfd_plugin_object_p (bfd *abfd)
 
   file.fd = fileno ((FILE *) iobfd->iostream);
 
+  if (!abfd->my_archive)
+    {
+      struct stat stat_buf;
+      if (fstat (file.fd, &stat_buf))
+        return NULL;
+      file.filesize = stat_buf.st_size;
+    }
+
   file.handle = abfd;
+  off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
   claim_file (&file, &claimed);
+  lseek(file.fd, cur_offset, SEEK_SET);
   if (!claimed)
     return NULL;
 

Re: [patch] Fix some plugin API issues in BFD

[Dave Korn]

On 20/02/2011 21:17, Rafael Ávila de Espíndola wrote:
> On 2011-02-20 14:54, Rafael Ávila de Espíndola wrote:
>> An updated patch is attached that also avoids calling onload multiple times.
> 
> Sorry, the correct one is now attached.


  Sorry for not answering earlier.  I don't have formal approval rights over
this area, so we still need a maintainer, but I can review this patch based on
my experience working in the area.

  The parts about only loading the plugin once and setting the filesize in the
(!abfd->my_archive) case are clearly correct.  The bit about saving and
restoring the filepos, I had to refresh my memory on, but since we cleared up
the issues around the ownership of the fd passed to the plugin, that's the
right solution too.  So AFAIC the patch is OK.

    cheers,
      DaveK

Re: [patch] Fix some plugin API issues in BFD

[DJ Delorie]

> +  static int have_plugin = 0;
> +  if (!have_loaded)

Blank line between declarations and code, please.  Otherwise OK.