gdb: merge debug symbol file lookup code from coffread & elfread paths

This commit merges the code that looks for and loads the separate
debug symbol files from coffread.c and elfread.c.  The factored out
code is moved into a new objfile::find_and_add_separate_symbol_file()
method.

For the elfread.c path there should be no user visible changes after
this commit.

For the coffread.c path GDB will now attempt to perform a debuginfod
lookup for the missing debug information, assuming that GDB can find a
build-id in the COFF file.

I don't know if COFF files can include a build-id, but I the existing
coffread.c code already includes a call to
find_separate_debug_file_by_build-id, so I know that it is at least OK
for GDB to ask a COFF file for a build-id.  If the COFF file doesn't
include a build-id then the debuginfod lookup code will not trigger
and the new code is harmless.

If the COFF file does include a build-id, then we're going to end up
asking debuginfod for the debug file.  As build-ids should be unique,
this should be harmless, even if debuginfod doesn't contain any
suitable debug data, it just costs us one debuginfod lookup, so I'm
not too worried about this for now.

As with the previous commit, I've done some minimal testing using the
mingw toolchain on a Linux machine, GDB seems to still access the
split debug information just fine.

Approved-By: Tom Tromey <tom@tromey.com>

diff --git a/gdb/coffread.c b/gdb/coffread.c
index e1415d6b2587a683475f42d40a5f8ac03a510e07..5898b3a8e08c32a73edea9ddb4a6d866f5705a28 100644 (file)
--- a/gdb/coffread.c
+++ b/gdb/coffread.c
@@ -40,8 +40,6 @@
 
 #include "coff-pe-read.h"
 
-#include "build-id.h"
-
 /* The objfile we are currently reading.  */
 
 static struct objfile *coffread_objfile;
@@ -729,26 +727,8 @@ coff_symfile_read (struct objfile *objfile, symfile_add_flags symfile_flags)
           && objfile->separate_debug_objfile == NULL
           && objfile->separate_debug_objfile_backlink == NULL)
     {
-      deferred_warnings warnings;
-      std::string debugfile
-       = find_separate_debug_file_by_buildid (objfile, &warnings);
-
-      if (debugfile.empty ())
-       debugfile
-         = find_separate_debug_file_by_debuglink (objfile, &warnings);
-
-      if (!debugfile.empty ())
-       {
-         gdb_bfd_ref_ptr debug_bfd (symfile_bfd_open (debugfile.c_str ()));
-
-         symbol_file_add_separate (debug_bfd, debugfile.c_str (),
-                                   symfile_flags, objfile);
-       }
-      /* If all the methods to collect the debuginfo failed, print any
-        warnings that were collected, this is a no-op if there are no
-        warnings.  */
-      if (debugfile.empty ())
-       warnings.emit ();
+      if (objfile->find_and_add_separate_symbol_file (symfile_flags))
+       gdb_assert (objfile->separate_debug_objfile != nullptr);
     }
 }
 

diff --git a/gdb/elfread.c b/gdb/elfread.c
index 7900dfbc388f7259e94a680e9c6bf5d758a81cb0..86e7f61586e85ef4901d1e47306ece9f375424d9 100644 (file)
--- a/gdb/elfread.c
+++ b/gdb/elfread.c
@@ -41,14 +41,12 @@
 #include "regcache.h"
 #include "bcache.h"
 #include "gdb_bfd.h"
-#include "build-id.h"
 #include "location.h"
 #include "auxv.h"
 #include "mdebugread.h"
 #include "ctfread.h"
 #include "gdbsupport/gdb_string_view.h"
 #include "gdbsupport/scoped_fd.h"
-#include "debuginfod-support.h"
 #include "dwarf2/public.h"
 #include "cli/cli-cmds.h"
 
@@ -1218,59 +1216,10 @@ elf_symfile_read_dwarf2 (struct objfile *objfile,
           && objfile->separate_debug_objfile == NULL
           && objfile->separate_debug_objfile_backlink == NULL)
     {
-      deferred_warnings warnings;
-
-      std::string debugfile
-       = find_separate_debug_file_by_buildid (objfile, &warnings);
-
-      if (debugfile.empty ())
-       debugfile = find_separate_debug_file_by_debuglink (objfile, &warnings);
-
-      if (!debugfile.empty ())
-       {
-         gdb_bfd_ref_ptr debug_bfd
-           (symfile_bfd_open_no_error (debugfile.c_str ()));
-
-         if (debug_bfd != nullptr)
-           symbol_file_add_separate (debug_bfd, debugfile.c_str (),
-                                     symfile_flags, objfile);
-       }
+      if (objfile->find_and_add_separate_symbol_file (symfile_flags))
+       gdb_assert (objfile->separate_debug_objfile != nullptr);
       else
-       {
-         has_dwarf2 = false;
-         const struct bfd_build_id *build_id
-           = build_id_bfd_get (objfile->obfd.get ());
-         const char *filename = bfd_get_filename (objfile->obfd.get ());
-
-         if (build_id != nullptr)
-           {
-             gdb::unique_xmalloc_ptr<char> symfile_path;
-             scoped_fd fd (debuginfod_debuginfo_query (build_id->data,
-                                                       build_id->size,
-                                                       filename,
-                                                       &symfile_path));
-
-             if (fd.get () >= 0)
-               {
-                 /* File successfully retrieved from server.  */
-                 gdb_bfd_ref_ptr debug_bfd
-                   (symfile_bfd_open_no_error (symfile_path.get ()));
-
-                 if (debug_bfd != nullptr
-                     && build_id_verify (debug_bfd.get (), build_id->size,
-                                         build_id->data))
-                   {
-                     symbol_file_add_separate (debug_bfd, symfile_path.get (),
-                                               symfile_flags, objfile);
-                     has_dwarf2 = true;
-                   }
-               }
-           }
-       }
-      /* If all the methods to collect the debuginfo failed, print the
-        warnings, this is a no-op if there are no warnings.  */
-      if (debugfile.empty () && !has_dwarf2)
-       warnings.emit ();
+       has_dwarf2 = false;
     }
 
   return has_dwarf2;

diff --git a/gdb/objfiles.h b/gdb/objfiles.h
index 4b8aa9bfcec1ace2dd9cacb7b9df1762247191a7..ec9d354e4a7a9205220f4ce7c48f456c7eeb920e 100644 (file)
--- a/gdb/objfiles.h
+++ b/gdb/objfiles.h
@@ -513,6 +513,16 @@ public:
 
   bool has_partial_symbols ();
 
+  /* Look for a separate debug symbol file for this objfile, make use of
+     build-id, debug-link, and debuginfod as necessary.  If a suitable
+     separate debug symbol file is found then it is loaded using a call to
+     symbol_file_add_separate (SYMFILE_FLAGS is passed through unmodified
+     to this call) and this function returns true.  If no suitable separate
+     debug symbol file is found and loaded then this function returns
+     false.  */
+
+  bool find_and_add_separate_symbol_file (symfile_add_flags symfile_flags);
+
   /* Return true if this objfile has any unexpanded symbols.  A return
      value of false indicates either, that this objfile has all its
      symbols fully expanded (i.e. fully read in), or that this objfile has

diff --git a/gdb/symfile-debug.c b/gdb/symfile-debug.c
index 850da4147a3f02969c9c6929e1339795df362709..961ae2327f760c184952af04b6cb4d7f7e8bbc24 100644 (file)
--- a/gdb/symfile-debug.c
+++ b/gdb/symfile-debug.c
@@ -35,6 +35,8 @@
 #include "block.h"
 #include "filenames.h"
 #include "cli/cli-style.h"
+#include "build-id.h"
+#include "debuginfod-support.h"
 
 /* We need to save a pointer to the real symbol functions.
    Plus, the debug versions are malloc'd because we have to NULL out the
@@ -558,6 +560,70 @@ objfile::require_partial_symbols (bool verbose)
     }
 }
 
+/* See objfiles.h.  */
+
+bool
+objfile::find_and_add_separate_symbol_file (symfile_add_flags symfile_flags)
+{
+  bool has_dwarf2 = true;
+
+  deferred_warnings warnings;
+
+  std::string debugfile
+    = find_separate_debug_file_by_buildid (this, &warnings);
+
+  if (debugfile.empty ())
+    debugfile = find_separate_debug_file_by_debuglink (this, &warnings);
+
+  if (!debugfile.empty ())
+    {
+      gdb_bfd_ref_ptr debug_bfd
+       (symfile_bfd_open_no_error (debugfile.c_str ()));
+
+      if (debug_bfd != nullptr)
+       symbol_file_add_separate (debug_bfd, debugfile.c_str (),
+                                 symfile_flags, this);
+    }
+  else
+    {
+      has_dwarf2 = false;
+      const struct bfd_build_id *build_id
+       = build_id_bfd_get (this->obfd.get ());
+      const char *filename = bfd_get_filename (this->obfd.get ());
+
+      if (build_id != nullptr)
+       {
+         gdb::unique_xmalloc_ptr<char> symfile_path;
+         scoped_fd fd (debuginfod_debuginfo_query (build_id->data,
+                                                   build_id->size,
+                                                   filename,
+                                                   &symfile_path));
+
+         if (fd.get () >= 0)
+           {
+             /* File successfully retrieved from server.  */
+             gdb_bfd_ref_ptr debug_bfd
+               (symfile_bfd_open_no_error (symfile_path.get ()));
+
+             if (debug_bfd != nullptr
+                 && build_id_verify (debug_bfd.get (), build_id->size,
+                                     build_id->data))
+               {
+                 symbol_file_add_separate (debug_bfd, symfile_path.get (),
+                                           symfile_flags, this);
+                 has_dwarf2 = true;
+               }
+           }
+       }
+    }
+  /* If all the methods to collect the debuginfo failed, print the
+     warnings, this is a no-op if there are no warnings.  */
+  if (debugfile.empty () && !has_dwarf2)
+    warnings.emit ();
+
+  return has_dwarf2;
+}
+
 \f
 /* Debugging version of struct sym_probe_fns.  */