* options.h (enum Incremental_disposition): Define.

(class General_options): Add new options: --incremental,
	--incremental_changed, --incremental_unchanged,
	--incremental_unknown.  Add incremental_disposition_ and
	implicit_incremental_ fields.
	(General_options::incremental_disposition): New function.
	(class Position_dependent_options): Add incremental_disposition
	option.
	(Position_dependent_options::copy_from_options): Set incremental
	dispositions.
	* options.cc (General_options::parse_incremental_changed): New
	function.
        (General_options::parse_incremental_unchanged): New function.
        (General_options::parse_incremental_unknown): New function.
        (General_options::General_options): Initialize new fields
	incremental_disposition_ and implicit_incremental_.
        (General_options::finalize): Check for uasge of --incremental-*
	without --incremental.

gold/ChangeLog

@@ -1,3 +1,24 @@
+2009-02-06  Mikolaj Zalewski  <mikolajz@google.com>
+
+	* options.h (enum Incremental_disposition): Define.
+	(class General_options): Add new options: --incremental,
+	--incremental_changed, --incremental_unchanged,
+	--incremental_unknown.  Add incremental_disposition_ and
+	implicit_incremental_ fields.
+	(General_options::incremental_disposition): New function.
+	(class Position_dependent_options): Add incremental_disposition
+	option.
+	(Position_dependent_options::copy_from_options): Set incremental
+	dispositions.
+	* options.cc (General_options::parse_incremental_changed): New
+	function.
+        (General_options::parse_incremental_unchanged): New function.
+        (General_options::parse_incremental_unknown): New function.
+        (General_options::General_options): Initialize new fields
+	incremental_disposition_ and implicit_incremental_.
+        (General_options::finalize): Check for uasge of --incremental-*
+	without --incremental.
+
 2009-02-06  Chris Demetriou  <cgd@google.com>
 
 	* gold.h (gold_undefined_symbol): Change to take only a Symbol

gold/options.cc

@@ -289,6 +289,30 @@ General_options::parse_defsym(const char*, const char* arg,
   cmdline->script_options().define_symbol(arg);
 }
 
+void
+General_options::parse_incremental_changed(const char*, const char*,
+                                           Command_line*)
+{
+  this->implicit_incremental_ = true;
+  this->incremental_disposition_ = INCREMENTAL_CHANGED;
+}
+
+void
+General_options::parse_incremental_unchanged(const char*, const char*,
+                                             Command_line*)
+{
+  this->implicit_incremental_ = true;
+  this->incremental_disposition_ = INCREMENTAL_UNCHANGED;
+}
+
+void
+General_options::parse_incremental_unknown(const char*, const char*,
+                                           Command_line*)
+{
+  this->implicit_incremental_ = true;
+  this->incremental_disposition_ = INCREMENTAL_CHECK;
+}
+
 void
 General_options::parse_library(const char*, const char* arg,
                                Command_line* cmdline)
@@ -621,7 +645,8 @@ namespace gold
 
 General_options::General_options()
   : execstack_status_(General_options::EXECSTACK_FROM_INPUT), static_(false),
-    do_demangle_(false), plugins_()
+    do_demangle_(false), plugins_(),
+    incremental_disposition_(INCREMENTAL_CHECK), implicit_incremental_(false)
 {
 }
 
@@ -839,6 +864,10 @@ General_options::finalize()
 		 "[0.0, 1.0)"),
 	       this->hash_bucket_empty_fraction());
 
+  if (this->implicit_incremental_ && !this->incremental())
+    gold_fatal(_("Options --incremental-changed, --incremental-unchanged, "
+                 "--incremental-unknown require the use of --incremental"));
+
   // FIXME: we can/should be doing a lot more sanity checking here.
 }
 

gold/options.h

@@ -56,6 +56,18 @@ class Position_dependent_options;
 class Target;
 class Plugin_manager;
 
+// Incremental build action for a specific file, as selected by the user.
+
+enum Incremental_disposition
+{
+  // Determine the status from the timestamp (default).
+  INCREMENTAL_CHECK,
+  // Assume the file changed from the previous build.
+  INCREMENTAL_CHANGED,
+  // Assume the file didn't change from the previous build.
+  INCREMENTAL_UNCHANGED
+};
+
 // The nested namespace is to contain all the global variables and
 // structs that need to be defined in the .h file, but do not need to
 // be used outside this class.
@@ -660,6 +672,19 @@ class General_options
   DEFINE_string(dynamic_linker, options::TWO_DASHES, 'I', NULL,
                 N_("Set dynamic linker path"), N_("PROGRAM"));
 
+  DEFINE_bool(incremental, options::TWO_DASHES, '\0', false,
+              N_("Work in progress; do not use"),
+              N_("Do a full build"));
+
+  DEFINE_special(incremental_changed, options::TWO_DASHES, '\0',
+                 N_("Assume files changed"), NULL);
+
+  DEFINE_special(incremental_unchanged, options::TWO_DASHES, '\0',
+                 N_("Assume files didn't change"), NULL);
+
+  DEFINE_special(incremental_unknown, options::TWO_DASHES, '\0',
+                 N_("Use timestamps to check files (default)"), NULL);
+
   DEFINE_special(just_symbols, options::TWO_DASHES, '\0',
                  N_("Read only symbol values from FILE"), N_("FILE"));
 
@@ -769,11 +794,11 @@ class General_options
                  N_("Do not link against shared libraries"), NULL);
 
   DEFINE_bool(gc_sections, options::TWO_DASHES, '\0', false,
-              N_("Remove unused sections"), 
+              N_("Remove unused sections"),
               N_("Don't remove unused sections (default)"));
- 
+
   DEFINE_bool(print_gc_sections, options::TWO_DASHES, '\0', false,
-              N_("List removed unused sections on stderr"), 
+              N_("List removed unused sections on stderr"),
               N_("Do not list removed unused sections"));
 
   DEFINE_bool(stats, options::TWO_DASHES, '\0', false,
@@ -969,6 +994,13 @@ class General_options
   in_dynamic_list(const char* symbol) const
   { return this->dynamic_list_.version_script_info()->symbol_is_local(symbol); }
 
+  // The disposition given by the --incremental-changed,
+  // --incremental-unchanged or --incremental-unknown option.  The
+  // value may change as we proceed parsing the command line flags.
+  Incremental_disposition
+  incremental_disposition() const
+  { return this->incremental_disposition_; }
+
  private:
   // Don't copy this structure.
   General_options(const General_options&);
@@ -1026,6 +1058,14 @@ class General_options
   // script.cc, we store this as a Script_options object, even though
   // we only use a single Version_tree from it.
   Script_options dynamic_list_;
+  // The disposition given by the --incremental-changed,
+  // --incremental-unchanged or --incremental-unknown option.  The
+  // value may change as we proceed parsing the command line flags.
+  Incremental_disposition incremental_disposition_;
+  // Wheater we have seen one of the options that require incremental
+  // build (--incremental-changed, --incremental-unchanged or
+  // --incremental-unknown)
+  bool implicit_incremental_;
 };
 
 // The position-dependent options.  We use this to store the state of
@@ -1062,12 +1102,14 @@ class Position_dependent_options
     this->set_Bdynamic(options.Bdynamic());
     this->set_format_enum(options.format_enum());
     this->set_whole_archive(options.whole_archive());
+    this->set_incremental_disposition(options.incremental_disposition());
   }
 
   DEFINE_posdep(as_needed, bool);
   DEFINE_posdep(Bdynamic, bool);
   DEFINE_posdep(format_enum, General_options::Object_format);
   DEFINE_posdep(whole_archive, bool);
+  DEFINE_posdep(incremental_disposition, Incremental_disposition);
 
  private:
   // This is a General_options with everything set to its default