Allow gdb to find debug symbols file by build-id for PE file format also

This promotes BFD's struct elf_build_id to the generic struct bfd_build_id,
populated when an ELF or PE BFD is read.

gdb is updated to use that, and to use the build-id to find symbols for PE files
also.

There is currently no generic way to extract the build-id from an object file,
perhaps an option to objdump to do this might make sense?

On x86_64-pc-cygwin, gdb's sepdebug.exp changes:

-# of unsupported tests          1
+# of expected passes            90

I don't seem to get consistent testsuite runs on i686-linux-gnu, but there
don't appear to be any regressions.

bfd/ChangeLog:

2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>

	* elf-bfd.h : Remove struct elf_build_id.
	* bfd.c : Add struct bfd_build_id.
	* bfd-in2.h: Regenerate.
	* elf.c (elfobj_grok_gnu_build_id): Update to use bfd_build_id.
	* libpei.h: Add protoype and macros for
	bfd_XXi_slurp_codeview_record.
	* peXXigen.c (_bfd_XXi_slurp_codeview_record): Make public
	* peicode.h (pe_bfd_read_buildid): Add.
	(pe_bfd_object_p): Use pe_bfd_read_buildid().

gdb/ChangeLog:

2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>

	* build-id.c: Don't include elf-bfd.h.
	(build_id_bfd_get): Use bfd_build_id.
	(build_id_verify): Ditto.
	* build-id.h: Ditto.
	(find_separate_debug_file_by_buildid): Ditto.
	* python/py-objfile.c: Don't include elf-bfd.h.
	(objfpy_get_build_id) Use bfd_build_id.
	(objfpy_build_id_matches, objfpy_lookup_objfile_by_build_id): Ditto.
	* coffread.c: Include build-id.h.
	(coff_symfile_read): Try find_separate_debug_file_by_buildid.

gdb/doc/ChangeLog:

2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>

	* gdb.texinfo (Separate Debug Files): Document that PE is also
	supported.

gdb/testsuite/ChangeLog:

2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>

	* gdb.base/sepdebug.exp: Add EXEEXT where needed.
	* lib/gdb.exp (get_build_id): Teach how to extract build-id from a
	PE file.
	* lib/future.exp (gdb_find_objdump): Add gdb_find_objdump.

Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>

11 files changed, 94 insertions, 45 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 4769bad..fdf519a 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,16 @@
+2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>
+
+	* build-id.c: Don't include elf-bfd.h.
+	(build_id_bfd_get): Use bfd_build_id.
+	(build_id_verify): Ditto.
+	* build-id.h: Ditto.
+	(find_separate_debug_file_by_buildid): Ditto.
+	* python/py-objfile.c: Don't include elf-bfd.h.
+	(objfpy_get_build_id) Use bfd_build_id.
+	(objfpy_build_id_matches, objfpy_lookup_objfile_by_build_id): Ditto.
+	* coffread.c: Include build-id.h.
+	(coff_symfile_read): Try find_separate_debug_file_by_buildid.
+
 2015-06-03  Jon Turney  <jon.turney@dronecode.org.uk>
 
 	* windows-nat.c (do_windows_fetch_inferior_registers)
diff --git a/gdb/build-id.c b/gdb/build-id.c
index 8f7bbb4..ebf9f45 100644
--- a/gdb/build-id.c
+++ b/gdb/build-id.c
@@ -19,7 +19,6 @@
 
 #include "defs.h"
 #include "bfd.h"
-#include "elf-bfd.h"
 #include "gdb_bfd.h"
 #include "build-id.h"
 #include "gdb_vecs.h"
@@ -30,19 +29,17 @@
 
 /* See build-id.h.  */
 
-const struct elf_build_id *
+const struct bfd_build_id *
 build_id_bfd_get (bfd *abfd)
 {
-  if (!bfd_check_format (abfd, bfd_object)
-      || bfd_get_flavour (abfd) != bfd_target_elf_flavour
-      /* Although this is ELF_specific, it is safe to do in generic
-	 code because it does not rely on any ELF-specific symbols at
-	 link time, and if the ELF code is not available in BFD, then
-	 ABFD will not have the ELF flavour.  */
-      || elf_tdata (abfd)->build_id == NULL)
+  if (!bfd_check_format (abfd, bfd_object))
     return NULL;
 
-  return elf_tdata (abfd)->build_id;
+  if (abfd->build_id != NULL)
+    return abfd->build_id;
+
+  /* No build-id */
+  return NULL;
 }
 
 /* See build-id.h.  */
@@ -50,7 +47,7 @@ build_id_bfd_get (bfd *abfd)
 int
 build_id_verify (bfd *abfd, size_t check_len, const bfd_byte *check)
 {
-  const struct elf_build_id *found;
+  const struct bfd_build_id *found;
   int retval = 0;
 
   found = build_id_bfd_get (abfd);
@@ -139,7 +136,7 @@ build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id)
 char *
 find_separate_debug_file_by_buildid (struct objfile *objfile)
 {
-  const struct elf_build_id *build_id;
+  const struct bfd_build_id *build_id;
 
   build_id = build_id_bfd_get (objfile->obfd);
   if (build_id != NULL)
diff --git a/gdb/build-id.h b/gdb/build-id.h
index f77dda2..bea761b 100644
--- a/gdb/build-id.h
+++ b/gdb/build-id.h
@@ -22,7 +22,7 @@
 
 /* Locate NT_GNU_BUILD_ID from ABFD and return its content.  */
 
-extern const struct elf_build_id *build_id_bfd_get (bfd *abfd);
+extern const struct bfd_build_id *build_id_bfd_get (bfd *abfd);
 
 /* Return true if ABFD has NT_GNU_BUILD_ID matching the CHECK value.
    Otherwise, issue a warning and return false.  */
diff --git a/gdb/coffread.c b/gdb/coffread.c
index 3b5a968..7722cdb 100644
--- a/gdb/coffread.c
+++ b/gdb/coffread.c
@@ -41,6 +41,7 @@
 #include "coff-pe-read.h"
 
 #include "psymtab.h"
+#include "build-id.h"
 
 extern void _initialize_coffread (void);
 
@@ -738,7 +739,10 @@ coff_symfile_read (struct objfile *objfile, int symfile_flags)
     {
       char *debugfile;
 
-      debugfile = find_separate_debug_file_by_debuglink (objfile);
+      debugfile = find_separate_debug_file_by_buildid (objfile);
+
+      if (debugfile == NULL)
+	debugfile = find_separate_debug_file_by_debuglink (objfile);
       make_cleanup (xfree, debugfile);
 
       if (debugfile)
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 4d42a37..53e6689 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>
+
+	* gdb.texinfo (Separate Debug Files): Document that PE is also
+	supported.
+
 2015-06-13  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* gdb.texinfo (TUI Commands): Bring all 'tui reg' commands into a
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index faca83e..81e3181 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -18170,7 +18170,7 @@ the executable and the debug file came from the same build.
 @item
 The executable contains a @dfn{build ID}, a unique bit string that is
 also present in the corresponding debug info file.  (This is supported
-only on some operating systems, notably those which use the ELF format
+only on some operating systems, when using the ELF or PE file formats
 for binary files and the @sc{gnu} Binutils.)  For more details about
 this feature, see the description of the @option{--build-id}
 command-line option in @ref{Options, , Command Line Options, ld.info,
diff --git a/gdb/python/py-objfile.c b/gdb/python/py-objfile.c
index c9528c3..5dc9ae6 100644
--- a/gdb/python/py-objfile.c
+++ b/gdb/python/py-objfile.c
@@ -23,7 +23,6 @@
 #include "objfiles.h"
 #include "language.h"
 #include "build-id.h"
-#include "elf-bfd.h"
 #include "symtab.h"
 
 typedef struct
@@ -134,7 +133,7 @@ objfpy_get_build_id (PyObject *self, void *closure)
 {
   objfile_object *obj = (objfile_object *) self;
   struct objfile *objfile = obj->objfile;
-  const struct elf_build_id *build_id = NULL;
+  const struct bfd_build_id *build_id = NULL;
 
   OBJFPY_REQUIRE_VALID (obj);
 
@@ -484,7 +483,7 @@ objfpy_build_id_ok (const char *string)
    It is assumed that objfpy_build_id_ok (string) returns TRUE.  */
 
 static int
-objfpy_build_id_matches (const struct elf_build_id *build_id,
+objfpy_build_id_matches (const struct bfd_build_id *build_id,
 			 const char *string)
 {
   size_t i;
@@ -542,7 +541,7 @@ objfpy_lookup_objfile_by_build_id (const char *build_id)
 
   ALL_OBJFILES (objfile)
     {
-      const struct elf_build_id *obfd_build_id;
+      const struct bfd_build_id *obfd_build_id;
 
       if (objfile->obfd == NULL)
 	continue;
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index e01f883..c564c66 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>
+
+	* gdb.base/sepdebug.exp: Add EXEEXT where needed.
+	* lib/gdb.exp (get_build_id): Teach how to extract build-id from a
+	PE file.
+	* lib/future.exp (gdb_find_objdump): Add gdb_find_objdump.
+
 2015-06-12  Antoine Tremblay  <antoine.tremblay@ericsson.com>
 
 	PR breakpoints/16465
diff --git a/gdb/testsuite/gdb.base/sepdebug.exp b/gdb/testsuite/gdb.base/sepdebug.exp
index 3194377..c363be4 100644
--- a/gdb/testsuite/gdb.base/sepdebug.exp
+++ b/gdb/testsuite/gdb.base/sepdebug.exp
@@ -42,7 +42,7 @@ if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {deb
 # the name of a debuginfo only file. This file will be stored in the
 # gdb.base/ subdirectory.
 
-if [gdb_gnu_strip_debug $binfile] {
+if [gdb_gnu_strip_debug $binfile$EXEEXT] {
     # check that you have a recent version of strip and objcopy installed
     unsupported "cannot produce separate debug info files"
     return -1
@@ -60,7 +60,7 @@ set new_name [standard_output_file ${testfile}${EXEEXT}]
 remote_exec build "rm -rf [file dirname $new_name]"
 
 remote_exec build "mkdir [file dirname $new_name]"
-remote_exec build "ln -s ${binfile} $new_name"
+remote_exec build "ln -s ${binfile}${EXEEXT} $new_name"
 clean_restart ${testfile}${EXEEXT}
 if { $gdb_file_cmd_debug_info != "debug" } then {
     fail "No debug information found."
@@ -716,10 +716,10 @@ proc test_different_dir {type test_different_dir xfail} {
 # the "set debug-file-directory" command.
 
 set different_dir [standard_output_file ${testfile}.dir]
-set debugfile "${different_dir}/[standard_output_file ${testfile}.debug]"
+set debugfile "${different_dir}/[standard_output_file ${testfile}${EXEEXT}.debug]"
 remote_exec build "rm -rf $different_dir"
 remote_exec build "mkdir -p [file dirname $debugfile]"
-remote_exec build "mv -f [standard_output_file ${testfile}.debug] $debugfile"
+remote_exec build "mv -f [standard_output_file ${testfile}${EXEEXT}.debug] $debugfile"
 
 test_different_dir debuglink $different_dir 0
 
@@ -727,7 +727,7 @@ test_different_dir debuglink $different_dir 0
 # Test CRC mismatch is reported.
 
 if {[build_executable sepdebug.exp sepdebug2 sepdebug2.c debug] != -1
-    && ![gdb_gnu_strip_debug [standard_output_file sepdebug2]]} {
+    && ![gdb_gnu_strip_debug [standard_output_file sepdebug2]$EXEEXT]} {
 
     remote_exec build "cp ${debugfile} [standard_output_file sepdebug2.debug]"
 
@@ -743,7 +743,7 @@ if {[build_executable sepdebug.exp sepdebug2 sepdebug2.c debug] != -1
 
 # NT_GNU_BUILD_ID / .note.gnu.build-id test:
 
-set build_id_debug_filename [build_id_debug_filename_get $binfile]
+set build_id_debug_filename [build_id_debug_filename_get $binfile$EXEEXT]
 if ![string compare $build_id_debug_filename ""] then {
     unsupported "build-id is not supported by the compiler"
 
diff --git a/gdb/testsuite/lib/future.exp b/gdb/testsuite/lib/future.exp
index 2fb635b..a27e120 100644
--- a/gdb/testsuite/lib/future.exp
+++ b/gdb/testsuite/lib/future.exp
@@ -104,6 +104,17 @@ proc gdb_find_objcopy {} {
     return $objcopy
 }
 
+# find target objdump
+proc gdb_find_objdump {} {
+    global OBJDUMP_FOR_TARGET
+    if [info exists OBJDUMP_FOR_TARGET] {
+	set objdump $OBJDUMP_FOR_TARGET
+    } else {
+	set objdump [transform objdump]
+    }
+    return $objdump
+}
+
 proc gdb_find_readelf {} {
     global READELF_FOR_TARGET
     if [info exists READELF_FOR_TARGET] {
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 41797e7..21a4638 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -4539,28 +4539,41 @@ gdb_caching_proc gdb_has_argv0 {
 # Returns "" if there is none.
 
 proc get_build_id { filename } {
-    set tmp [standard_output_file "${filename}-tmp"]
-    set objcopy_program [gdb_find_objcopy]
-
-    set result [catch "exec $objcopy_program -j .note.gnu.build-id -O binary $filename $tmp" output]
-    verbose "result is $result"
-    verbose "output is $output"
-    if {$result == 1} {
-	return ""
+    if { ([istarget "*-*-mingw*"]
+	  || [istarget *-*-cygwin*]) } {
+	set objdump_program [gdb_find_objdump]
+	set result [catch {set data [exec $objdump_program -p $filename | grep signature | cut "-d " -f4]} output]
+	verbose "result is $result"
+	verbose "output is $output"
+	if {$result == 1} {
+	    return ""
+	}
+	return $data
     }
-    set fi [open $tmp]
-    fconfigure $fi -translation binary
-    # Skip the NOTE header.
-    read $fi 16
-    set data [read $fi]
-    close $fi
-    file delete $tmp
-    if ![string compare $data ""] then {
-	return ""
+    else
+    {
+	set tmp [standard_output_file "${filename}-tmp"]
+	set objcopy_program [gdb_find_objcopy]
+	set result [catch "exec $objcopy_program -j .note.gnu.build-id -O binary $filename $tmp" output]
+	verbose "result is $result"
+	verbose "output is $output"
+	if {$result == 1} {
+	    return ""
+	}
+	set fi [open $tmp]
+	fconfigure $fi -translation binary
+	# Skip the NOTE header.
+	read $fi 16
+	set data [read $fi]
+	close $fi
+	file delete $tmp
+	if ![string compare $data ""] then {
+	    return ""
+	}
+	# Convert it to hex.
+	binary scan $data H* data
+	return $data
     }
-    # Convert it to hex.
-    binary scan $data H* data
-    return $data
 }
 
 # Return the build-id hex string (usually 160 bits as 40 hex characters)