Stop readekf and objdump from aggressively following links.

* dwarf.c (dwarf_select_sections_by_names): Return zero if no
	sections were selected.
	(dwarf_select_sections_by_letters): Likewise.
	* dwarf.h: (dwarf_select_sections_by_names): Update prototype.
	(dwarf_select_sections_by_letters): Update prototype.
	* objdump.c (might_need_separate_debug_info): New function.
	(dump_bfd): Call new function before attempting to load separate
	debug info files.
	(main): Do not enable dwarf section dumping for -WK or -WN.
	* readelf.c (parse_args): Do not enable dwarf section dumping for
	-wK or -wN.
	(might_need_separate_debug_info): New function.
	(process_object): Call new function before attempting to load
	separate debug info files.
	* testsuite/binutils-all/debuginfo.exp: Expect -WE and -wE
	debuginfod tests to pass.
	* testsuite/binutils-all/objdump.Wk: Add extra regexps.
	* testsuite/binutils-all/readelf.k: Add extra regexps.

binutils/ChangeLog

@@ -1,3 +1,24 @@
+2022-05-20  Nick Clifton  <nickc@redhat.com>
+
+	* dwarf.c (dwarf_select_sections_by_names): Return zero if no
+	sections were selected.
+	(dwarf_select_sections_by_letters): Likewise.
+	* dwarf.h: (dwarf_select_sections_by_names): Update prototype.
+	(dwarf_select_sections_by_letters): Update prototype.
+	* objdump.c (might_need_separate_debug_info): New function.
+	(dump_bfd): Call new function before attempting to load separate
+	debug info files.
+	(main): Do not enable dwarf section dumping for -WK or -WN.
+	* readelf.c (parse_args): Do not enable dwarf section dumping for
+	-wK or -wN.
+	(might_need_separate_debug_info): New function.
+	(process_object): Call new function before attempting to load
+	separate debug info files.
+	* testsuite/binutils-all/debuginfo.exp: Expect -WE and -wE
+	debuginfod tests to pass.
+	* testsuite/binutils-all/objdump.Wk: Add extra regexps.
+	* testsuite/binutils-all/readelf.k: Add extra regexps.
+
 2022-05-19  Nick Clifton  <nickc@redhat.com>
 
 	* dlltool.c (run): Initialise errmsg_fmt.

binutils/dwarf.c

@@ -12062,7 +12062,11 @@ free_debug_memory (void)
   free_dwo_info ();
 }
 
-void
+/* Enable display of specific DWARF sections as determined by the comma
+   separated strings in NAMES.  Returns non-zero if any displaying was
+   enabled.  */
+
+int
 dwarf_select_sections_by_names (const char *names)
 {
   typedef struct
@@ -12115,6 +12119,7 @@ dwarf_select_sections_by_names (const char *names)
     };
 
   const char *p;
+  int result = 0;
 
   p = names;
   while (*p)
@@ -12129,6 +12134,7 @@ dwarf_select_sections_by_names (const char *names)
 	      && (p[len] == ',' || p[len] == '\0'))
 	    {
 	      * entry->variable = entry->val;
+	      result |= entry->val;
 
 	      /* The --debug-dump=frames-interp option also
 		 enables the --debug-dump=frames option.  */
@@ -12151,48 +12157,82 @@ dwarf_select_sections_by_names (const char *names)
       if (*p == ',')
 	p++;
     }
+
+  return result;
 }
 
-void
+/* Enable display of specific DWARF sections as determined by the characters
+   in LETTERS.  Returns non-zero if any displaying was enabled.  */
+
+int
 dwarf_select_sections_by_letters (const char *letters)
 {
-  unsigned int lindex = 0;
+  typedef struct
+  {
+    const char   letter;
+    int *        variable;
+    int          val;
+    bool         cont;
+  }
+  debug_dump_letter_opts;
 
-  while (letters[lindex])
+  static const debug_dump_letter_opts letter_table [] =
-    switch (letters[lindex++])
+    {
-      {
+      { 'A', & do_debug_addr, 1, false},
-      case 'A':	do_debug_addr = 1; break;
+      { 'a', & do_debug_abbrevs, 1, false },
-      case 'a':	do_debug_abbrevs = 1; break;
+      { 'c', & do_debug_cu_index, 1, false },
-      case 'c':	do_debug_cu_index = 1; break;
 #ifdef HAVE_LIBDEBUGINFOD
-      case 'D': use_debuginfod = 1; break;
+      { 'D', & use_debuginfod, 1, false },
-      case 'E': use_debuginfod = 0; break;
+      { 'E', & use_debuginfod, 0, false },
 #endif
-      case 'F':	do_debug_frames_interp = 1; /* Fall through.  */
+      { 'F', & do_debug_frames_interp, 1, true }, /* Note the fall through.  */
-      case 'f':	do_debug_frames = 1; break;
+      { 'f', & do_debug_frames, 1, false },
-      case 'g':	do_gdb_index = 1; break;
+      { 'g', & do_gdb_index, 1, false },
-      case 'i':	do_debug_info = 1; break;
+      { 'i', & do_debug_info, 1, false },
-      case 'K': do_follow_links = 1; break;
+      { 'K', & do_follow_links, 1, false },
-      case 'N': do_follow_links = 0; break;
+      { 'k', & do_debug_links, 1, false },
-      case 'k':	do_debug_links = 1; break;
+      { 'L', & do_debug_lines, FLAG_DEBUG_LINES_DECODED, false },
-      case 'l':	do_debug_lines |= FLAG_DEBUG_LINES_RAW;	break;
+      { 'l', & do_debug_lines, FLAG_DEBUG_LINES_RAW, false },
-      case 'L':	do_debug_lines |= FLAG_DEBUG_LINES_DECODED; break;
+      { 'm', & do_debug_macinfo, 1, false },
-      case 'm': do_debug_macinfo = 1; break;
+      { 'N', & do_follow_links, 0, false },
-      case 'O':	do_debug_str_offsets = 1; break;
+      { 'O', & do_debug_str_offsets, 1, false },
-      case 'o':	do_debug_loc = 1; break;
+      { 'o', & do_debug_loc, 1, false },
-      case 'p':	do_debug_pubnames = 1; break;
+      { 'p', & do_debug_pubnames, 1, false },
-      case 'R':	do_debug_ranges = 1; break;
+      { 'R', & do_debug_ranges, 1, false },
-      case 'r':	do_debug_aranges = 1; break;
+      { 'r', & do_debug_aranges, 1, false },
-      case 's':	do_debug_str = 1; break;
+      { 's', & do_debug_str, 1, false },
-      case 'T': do_trace_aranges = 1; break;
+      { 'T', & do_trace_aranges, 1, false },
-      case 't': do_debug_pubtypes = 1; break;
+      { 't', & do_debug_pubtypes, 1, false },
-      case 'U': do_trace_info = 1; break;
+      { 'U', & do_trace_info, 1, false },
-      case 'u': do_trace_abbrevs = 1; break;
+      { 'u', & do_trace_abbrevs, 1, false },
+      { 0, NULL, 0, false }
+    };
 
-      default:
+  int result = 0;
-	warn (_("Unrecognized debug option '%s'\n"), letters);
+
-	break;
+  while (* letters)
-      }
+    {
+      const debug_dump_letter_opts * entry;
+
+      for (entry = letter_table; entry->letter; entry++)
+	{
+	  if (entry->letter == * letters)
+	    {
+	      * entry->variable |= entry->val;
+	      result |= entry->val;
+
+	      if (! entry->cont)
+		break;
+	    }
+	}
+
+      if (entry->letter == 0)
+	warn (_("Unrecognized debug letter option '%c'\n"), * letters);
+
+      letters ++;
+    }
+
+  return result;
 }
 
 void

binutils/dwarf.h

@@ -250,8 +250,8 @@ extern void *open_debug_file (const char *);
 
 extern void free_debug_memory (void);
 
-extern void dwarf_select_sections_by_names (const char *);
+extern int dwarf_select_sections_by_names (const char *);
-extern void dwarf_select_sections_by_letters (const char *);
+extern int dwarf_select_sections_by_letters (const char *);
 extern void dwarf_select_sections_all (void);
 
 extern unsigned int * find_cu_tu_set (void *, unsigned int);

binutils/objdump.c

@@ -5188,6 +5188,26 @@ sign_extend_address (bfd *abfd ATTRIBUTE_UNUSED,
   return (((vma & ((mask << 1) - 1)) ^ mask) - mask);
 }
 
+static bool
+might_need_separate_debug_info (bool is_mainfile)
+{
+  /* We do not follow links from debug info files.  */
+  if (! is_mainfile)
+    return false;
+
+  /* Since do_follow_links might be enabled by default, only treat it as an
+     indication that separate files should be loaded if setting it was a
+     deliberate user action.  */
+  if (DEFAULT_FOR_FOLLOW_LINKS == 0 && do_follow_links)
+    return true;
+  
+  if (process_links || dump_symtab || dump_debugging
+      || dump_dwarf_section_info)
+    return true;
+
+  return false;  
+}
+
 /* Dump selected contents of ABFD.  */
 
 static void
@@ -5202,16 +5222,8 @@ dump_bfd (bfd *abfd, bool is_mainfile)
   else
     byte_get = NULL;
 
-  /* Load any separate debug information files.
+  /* Load any separate debug information files.  */
-     We do this now and without checking do_follow_links because separate
+  if (byte_get != NULL && might_need_separate_debug_info (is_mainfile))
-     debug info files may contain symbol tables that we will need when
-     displaying information about the main file.  Any memory allocated by
-     load_separate_debug_files will be released when we call
-     free_debug_memory below.
-
-     The test on is_mainfile is there because the chain of separate debug
-     info files is a global variable shared by all invocations of dump_bfd.  */
-  if (byte_get != NULL && is_mainfile)
     {
       load_separate_debug_files (abfd, bfd_get_filename (abfd));
 
@@ -5783,20 +5795,30 @@ main (int argc, char **argv)
 	  do_follow_links = true;
 	  break;
 	case 'W':
-	  dump_dwarf_section_info = true;
 	  seenflag = true;
 	  if (optarg)
-	    dwarf_select_sections_by_letters (optarg);
+	    {
+	      if (dwarf_select_sections_by_letters (optarg))
+		dump_dwarf_section_info = true;
+	    }
 	  else
-	    dwarf_select_sections_all ();
+	    {
+	      dump_dwarf_section_info = true;
+	      dwarf_select_sections_all ();
+	    }
 	  break;
 	case OPTION_DWARF:
-	  dump_dwarf_section_info = true;
 	  seenflag = true;
 	  if (optarg)
-	    dwarf_select_sections_by_names (optarg);
+	    {
+	      if (dwarf_select_sections_by_names (optarg))
+		dump_dwarf_section_info = true;
+	    }
 	  else
-	    dwarf_select_sections_all ();
+	    {
+	      dwarf_select_sections_all ();
+	      dump_dwarf_section_info = true;
+	    }
 	  break;
 	case OPTION_DWARF_DEPTH:
 	  {

binutils/readelf.c

@@ -5526,31 +5526,39 @@ parse_args (struct dump_data *dumpdata, int argc, char ** argv)
 	  decompress_dumps = true;
 	  break;
 	case 'w':
-	  do_dump = true;
-	  dump_any_debugging = true;
 	  if (optarg == NULL)
 	    {
 	      do_debugging = true;
+	      do_dump = true;
+	      dump_any_debugging = true;
 	      dwarf_select_sections_all ();
 	    }
 	  else
 	    {
 	      do_debugging = false;
-	      dwarf_select_sections_by_letters (optarg);
+	      if (dwarf_select_sections_by_letters (optarg))
+		{
+		  do_dump = true;
+		  dump_any_debugging = true;
+		}
 	    }
 	  break;
 	case OPTION_DEBUG_DUMP:
-	  do_dump = true;
-	  dump_any_debugging = true;
 	  if (optarg == NULL)
 	    {
+	      do_dump = true;
 	      do_debugging = true;
+	      dump_any_debugging = true;
 	      dwarf_select_sections_all ();
 	    }
 	  else
 	    {
 	      do_debugging = false;
-	      dwarf_select_sections_by_names (optarg);
+	      if (dwarf_select_sections_by_names (optarg))
+		{
+		  do_dump = true;
+		  dump_any_debugging = true;
+		}
 	    }
 	  break;
 	case OPTION_DWARF_DEPTH:
@@ -22252,6 +22260,26 @@ initialise_dump_sects (Filedata * filedata)
     }
 }
 
+static bool
+might_need_separate_debug_info (Filedata * filedata)
+{
+  /* Debuginfo files do not need further separate file loading.  */
+  if (filedata->file_header.e_shstrndx == SHN_UNDEF)
+    return false;
+
+  /* Since do_follow_links might be enabled by default, only treat it as an
+     indication that separate files should be loaded if setting it was a
+     deliberate user action.  */
+  if (DEFAULT_FOR_FOLLOW_LINKS == 0 && do_follow_links)
+    return true;
+  
+  if (process_links || do_syms || do_unwind 
+      || dump_any_debugging || do_dump || do_debugging)
+    return true;
+
+  return false;
+}
+
 /* Process one ELF object file according to the command line options.
    This file may actually be stored in an archive.  The file is
    positioned at the start of the ELF object.  Returns TRUE if no
@@ -22335,7 +22363,7 @@ process_object (Filedata * filedata)
   if (! process_version_sections (filedata))
     res = false;
 
-  if (filedata->file_header.e_shstrndx != SHN_UNDEF)
+  if (might_need_separate_debug_info (filedata))
     have_separate_files = load_separate_debug_files (filedata, filedata->file_name);
   else
     have_separate_files = false;

binutils/testsuite/binutils-all/debuginfod.exp

@@ -189,7 +189,7 @@ if { [regexp ".*DEBUGINFOD.*" $conf_objdump] } {
     test_fetch_debugaltlink $OBJDUMP "-Wk"
 
     set test "disabling debuginfod access"
-    setup_xfail *-*-*
+    # setup_xfail *-*-*
     test_fetch_debuglink $OBJDUMP "-W -WE"
     set test "debuginfod"
 
@@ -202,7 +202,7 @@ if { [regexp ".*DEBUGINFOD.*" $conf_readelf] } {
     test_fetch_debugaltlink $READELF "-wk"
 
     set test "disabling debuginfod access"
-    setup_xfail *-*-*
+    # setup_xfail *-*-*
     test_fetch_debuglink $READELF "-w -wE"
     set test "debuginfod"
 

binutils/testsuite/binutils-all/objdump.Wk

@@ -1,8 +1,9 @@
+#...
 tmpdir/debuglink\.o:     file format .*
-Contents of the \.gnu_debuglink section:
+Contents of the \.gnu_debuglink section.*
   Separate debug info file: this_is_a_debuglink\.debug
   CRC value: 0x12345678
-Contents of the \.gnu_debugaltlink section:
+Contents of the \.gnu_debugaltlink section.*
   Separate debug info file: linkdebug\.debug
   Build-ID \(0x18 bytes\):
  00 11 22 33 44 55 66 77 88 99 aa bb cc dd ee ff 01 23 45 67 89 ab cd ef

binutils/testsuite/binutils-all/readelf.k

@@ -1,7 +1,8 @@
-Contents of the \.gnu_debuglink section:
+#...
+Contents of the \.gnu_debuglink section.*
   Separate debug info file: this_is_a_debuglink\.debug
   CRC value: 0x12345678
-Contents of the \.gnu_debugaltlink section:
+Contents of the \.gnu_debugaltlink section.*
   Separate debug info file: linkdebug\.debug
   Build-ID \(0x18 bytes\):
  00 11 22 33 44 55 66 77 88 99 aa bb cc dd ee ff 01 23 45 67 89 ab cd ef