gdb, gdbserver: use structured bindings in a few places

I wanted to change one of these, so I searched for more similar
instances, while at it.  I think this looks a bit tidier, over unpacking
the pairs by hand.

Change-Id: Ife4b678f7a6aed01803434197c564d2ab93532a7
Approved-By: Tom Tromey <tom@tromey.com>

gdb/corelow.c

@@ -451,11 +451,8 @@ core_target::build_file_mappings ()
   const bfd_build_id *core_build_id
     = build_id_bfd_get (current_program_space->core_bfd ());
 
-  for (const auto &iter : mapped_files)
+  for (const auto &[filename, file_data] : mapped_files)
     {
-      const std::string &filename = iter.first;
-      const mapped_file &file_data = iter.second;
-
       /* If this mapped file has the same build-id as was discovered for
 	 the core-file itself, then we assume this is the main
 	 executable.  Record the filename as we can use this later.  */

gdb/dictionary.c

@@ -952,14 +952,9 @@ mdict_create_hashed (struct obstack *obstack,
   retval->n_allocated_dictionaries = nsyms.size ();
 
   int idx = 0;
-  for (const auto &pair : nsyms)
-    {
-      enum language language = pair.first;
-      std::vector<symbol *> symlist = pair.second;
-
-      retval->dictionaries[idx++]
-	= dict_create_hashed (obstack, language, symlist);
-    }
+  for (const auto &[language, symlist] : nsyms)
+    retval->dictionaries[idx++] = dict_create_hashed (obstack, language,
+						      symlist);
 
   return retval;
 }
@@ -997,14 +992,9 @@ mdict_create_linear (struct obstack *obstack,
   retval->n_allocated_dictionaries = nsyms.size ();
 
   int idx = 0;
-  for (const auto &pair : nsyms)
-    {
-      enum language language = pair.first;
-      std::vector<symbol *> symlist = pair.second;
-
-      retval->dictionaries[idx++]
-	= dict_create_linear (obstack, language, symlist);
-    }
+  for (const auto &[language, symlist] : nsyms)
+    retval->dictionaries[idx++] = dict_create_linear (obstack, language,
+						      symlist);
 
   return retval;
 }
@@ -1135,10 +1125,8 @@ mdict_add_pending (struct multidictionary *mdict,
   gdb::unordered_map<enum language, std::vector<symbol *>> nsyms
     = collate_pending_symbols_by_language (symbol_list);
 
-  for (const auto &pair : nsyms)
+  for (const auto &[language, symlist] : nsyms)
     {
-      enum language language = pair.first;
-      std::vector<symbol *> symlist = pair.second;
       struct dictionary *dict = find_language_dictionary (mdict, language);
 
       if (dict == nullptr)

gdb/solib-svr4.c

@@ -3591,16 +3591,11 @@ find_debug_base_for_solib (const solib *solib)
   auto *lm_info
     = gdb::checked_static_cast<const lm_info_svr4 *> (solib->lm_info.get ());
 
-  for (const auto &tuple : info->solib_lists)
-    {
-      CORE_ADDR debug_base = tuple.first;
-      const std::vector<svr4_so> &sos = tuple.second;
-
-      for (const svr4_so &so : sos)
-	if (svr4_same (solib->original_name.c_str (), so.name.c_str (),
-		       *lm_info, *so.lm_info))
-	  return debug_base;
-    }
+  for (const auto &[debug_base, sos] : info->solib_lists)
+    for (const svr4_so &so : sos)
+      if (svr4_same (solib->original_name.c_str (), so.name.c_str (), *lm_info,
+		     *so.lm_info))
+	return debug_base;
 
   return 0;
 }

gdb/solib.c

@@ -1210,14 +1210,13 @@ info_linker_namespace_command (const char *pattern, int from_tty)
 
   bool ns_separator = false;
 
-  for (auto &solibs_pair : all_solibs_to_print)
+  for (const auto &[ns, solibs_to_print] : all_solibs_to_print)
     {
       if (ns_separator)
 	uiout->message ("\n\n");
       else
 	ns_separator = true;
-      int ns = solibs_pair.first;
-      std::vector<const solib *> solibs_to_print = solibs_pair.second;
+
       if (solibs_to_print.size () == 0)
 	{
 	  uiout->message (_("Linker namespace [[%d]] is not active.\n"), ns);

gdb/symtab.c

@@ -6986,11 +6986,8 @@ info_module_subcommand (bool quiet, const char *module_regexp,
 
   const char *last_filename = "";
   const symbol *last_module_symbol = nullptr;
-  for (const module_symbol_search &ms : module_symbols)
+  for (const auto &[p, q] : module_symbols)
     {
-      const symbol_search &p = ms.first;
-      const symbol_search &q = ms.second;
-
       gdb_assert (q.symbol != nullptr);
 
       if (last_module_symbol != p.symbol)

gdbserver/server.cc

@@ -1018,20 +1018,15 @@ handle_general_set (char *own_buf)
 	    });
 	}
 
-      for (const auto &iter : set_options)
-	{
-	  thread_info *thread = iter.first;
-	  gdb_thread_options options = iter.second;
+      for (const auto [thread, options] : set_options)
+	if (thread->thread_options != options)
+	  {
+	    threads_debug_printf ("[options for %s are now %s]\n",
+				  target_pid_to_str (thread->id).c_str (),
+				  to_string (options).c_str ());
 
-	  if (thread->thread_options != options)
-	    {
-	      threads_debug_printf ("[options for %s are now %s]\n",
-				    target_pid_to_str (thread->id).c_str (),
-				    to_string (options).c_str ());
-
-	      thread->thread_options = options;
-	    }
-	}
+	    thread->thread_options = options;
+	  }
 
       write_ok (own_buf);
       return;