4 files changed, 86 insertions, 14 deletions
diff --git a/gcc/go/ChangeLog b/gcc/go/ChangeLog
index b68f4bb070b..d70dc40c4c6 100644
--- a/gcc/go/ChangeLog
+++ b/gcc/go/ChangeLog
@@ -1,3 +1,17 @@
+2010-12-06  Ian Lance Taylor  <iant@google.com>
+
+	PR other/46789
+	PR bootstrap/46812
+	* go-lang.c (go_char_p): Define type and vectors.
+	(go_search_dirs): New static variable.
+	(go_langhook_handle_option): Use version and version/machine
+	directories for -L.
+	(go_langhook_post_options): Add non-specific -L paths.
+	* Make-lang.in (go/go-lang.o): Define DEFAULT_TARGET_VERSION and
+	DEFAULT_TARGET_MACHINE when compiling.
+	* gccgo.texi (Invoking gccgo): Only document -L for linking.
+	(Import and Export): Don't mention -L for finding import files.
+
 2010-12-03  Ian Lance Taylor  <iant@google.com>
 
 	PR bootstrap/46776
diff --git a/gcc/go/Make-lang.in b/gcc/go/Make-lang.in
index fc981d4a5fb..4d008161a1c 100644
--- a/gcc/go/Make-lang.in
+++ b/gcc/go/Make-lang.in
@@ -218,10 +218,16 @@ GO_IMPORT_H = go/gofrontend/import.h go/gofrontend/export.h
 
 go/go-backend.o: go/go-backend.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
 	$(TREE_H) $(TM_H) $(TM_P_H)
+
 go/go-lang.o: go/go-lang.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(OPTS_H) \
-	$(TREE_H) $(GIMPLE_H) $(GGC_H) $(TOPLEV_H) debug.h options.h \
-	$(FLAGS_H) convert.h $(DIAGNOSTIC_H) langhooks.h $(LANGHOOKS_DEF_H) \
-	$(EXCEPT_H) $(TARGET_H) $(GO_C_H) gt-go-go-lang.h gtype-go.h
+		$(TREE_H) $(GIMPLE_H) $(GGC_H) $(TOPLEV_H) debug.h options.h \
+		$(FLAGS_H) convert.h $(DIAGNOSTIC_H) langhooks.h \
+		$(LANGHOOKS_DEF_H) $(EXCEPT_H) $(TARGET_H) $(GO_C_H) \
+		gt-go-go-lang.h gtype-go.h
+	$(COMPILER) $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) \
+	  -DDEFAULT_TARGET_VERSION=\"$(version)\" \
+	  -DDEFAULT_TARGET_MACHINE=\"$(target_noncanonical)\" \
+	  -c $< $(OUTPUT_OPTION)
 
 GOINCLUDES = -I $(srcdir)/go -I $(srcdir)/go/gofrontend
 
diff --git a/gcc/go/gccgo.texi b/gcc/go/gccgo.texi
index 0e41261eec1..b6f8910a8db 100644
--- a/gcc/go/gccgo.texi
+++ b/gcc/go/gccgo.texi
@@ -154,8 +154,8 @@ compile time.
 
 @item -L@var{dir}
 @cindex @option{-L}
-When compiling, synonymous with @option{-I}.  When linking, specify a
-library search directory, as with @command{gcc}.
+When linking, specify a library search directory, as with
+@command{gcc}.
 
 @item -fgo-prefix=@var{string}
 @cindex @option{-fgo-prefix}
@@ -198,11 +198,10 @@ first one that it finds.
 @end table
 
 The compiler will search for these files in the directories named by
-any @option{-I} or @option{-L} options, in order in which the
-directories appear on the command line.  The compiler will then search
-several standard system directories.  Finally the compiler will search
-the current directory (to search the current directory earlier, use
-@samp{-I.}).
+any @option{-I} options, in order in which the directories appear on
+the command line.  The compiler will then search several standard
+system directories.  Finally the compiler will search the current
+directory (to search the current directory earlier, use @samp{-I.}).
 
 The compiler will extract the export information directly from the
 compiled object file.  The file @file{@var{gopackage}.gox} will
diff --git a/gcc/go/go-lang.c b/gcc/go/go-lang.c
index 9c85ab7f7a2..0f3c1838f4b 100644
--- a/gcc/go/go-lang.c
+++ b/gcc/go/go-lang.c
@@ -162,6 +162,17 @@ go_langhook_init_options_struct (struct gcc_options *opts)
   opts->x_flag_non_call_exceptions = 1;
 }
 
+/* Infrastructure for a VEC of char * pointers.  */
+
+typedef const char *go_char_p;
+DEF_VEC_P(go_char_p);
+DEF_VEC_ALLOC_P(go_char_p, heap);
+
+/* The list of directories to search after all the Go specific
+   directories have been searched.  */
+
+static VEC(go_char_p, heap) *go_search_dirs;
+
 /* Handle Go specific options.  Return 0 if we didn't do anything.  */
 
 static bool
@@ -179,13 +190,47 @@ go_langhook_handle_option (
   switch (code)
     {
     case OPT_I:
-    case OPT_L:
-      /* For the compiler, we currently handle -I and -L exactly the
-	 same way: they give us a directory to search for import
-	 statements.  */
       go_add_search_path (arg);
       break;
 
+    case OPT_L:
+      /* A -L option is assumed to come from the compiler driver.
+	 This is a system directory.  We search the following
+	 directories, if they exist, before this one:
+	   dir/go/VERSION
+	   dir/go/VERSION/MACHINE
+	 This is like include/c++.  */
+      {
+	static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
+	size_t len;
+	char *p;
+	struct stat st;
+
+	len = strlen (arg);
+	p = XALLOCAVEC (char,
+			(len + sizeof "go" + sizeof DEFAULT_TARGET_VERSION
+			 + sizeof DEFAULT_TARGET_MACHINE + 3));
+	strcpy (p, arg);
+	if (len > 0 && !IS_DIR_SEPARATOR (p[len - 1]))
+	  strcat (p, dir_separator_str);
+	strcat (p, "go");
+	strcat (p, dir_separator_str);
+	strcat (p, DEFAULT_TARGET_VERSION);
+	if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
+	  {
+	    go_add_search_path (p);
+	    strcat (p, dir_separator_str);
+	    strcat (p, DEFAULT_TARGET_MACHINE);
+	    if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
+	      go_add_search_path (p);
+	  }
+
+	/* Search ARG too, but only after we've searched to Go
+	   specific directories for all -L arguments.  */
+	VEC_safe_push (go_char_p, heap, go_search_dirs, arg);
+      }
+      break;
+
     case OPT_fgo_dump_:
       ret = go_enable_dump (arg) ? true : false;
       break;
@@ -207,8 +252,16 @@ go_langhook_handle_option (
 static bool
 go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 {
+  unsigned int ix;
+  const char *dir;
+
   gcc_assert (num_in_fnames > 0);
 
+  FOR_EACH_VEC_ELT (go_char_p, go_search_dirs, ix, dir)
+    go_add_search_path (dir);
+  VEC_free (go_char_p, heap, go_search_dirs);
+  go_search_dirs = NULL;
+
   if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
     flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;