Move clearing of flag_strict_aliasing to gcc interface.

From-SVN: r168774

6 files changed, 46 insertions, 20 deletions

diff --git a/gcc/go/ChangeLog b/gcc/go/ChangeLog
index d25a523..6354ce5 100644
--- a/gcc/go/ChangeLog
+++ b/gcc/go/ChangeLog
@@ -1,3 +1,12 @@
+2011-01-13  Ian Lance Taylor  <iant@google.com>
+
+	* go-backend.c: Include "rtl.h" and "target.h".
+	(go_imported_unsafe): New function.
+	* go-c.h (go_imported_unsafe): Declare.
+	* Make-lang.in (go/go-backend.o): Depend on $(RTL_H).
+	(go/gogo-tree.o): Remove dependency on $(RTL_H).
+	(go/unsafe.o): Depend on $(GO_C_H).
+
 2010-12-31  Joern Rennecke  <amylaar@spamcop.net>
 
 	PR go/47113
diff --git a/gcc/go/Make-lang.in b/gcc/go/Make-lang.in
index 48799f4..a8c3aa6 100644
--- a/gcc/go/Make-lang.in
+++ b/gcc/go/Make-lang.in
@@ -1,6 +1,6 @@
 # Make-lang.in -- Top level -*- makefile -*- fragment for gcc Go frontend.
 
-# Copyright (C) 2009, 2010 Free Software Foundation, Inc.
+# Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc.
 
 # This file is part of GCC.
 
@@ -221,7 +221,7 @@ GO_EXPRESSIONS_H = go/gofrontend/expressions.h go/gofrontend/operator.h
 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)
+	$(TM_H) $(RTL_H) $(TREE_H) $(TM_P_H) $(TARGET_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 \
@@ -254,7 +254,7 @@ go/go-dump.o: go/gofrontend/go-dump.cc $(GO_SYSTEM_H) $(GO_C_H) \
 	go/gofrontend/go-dump.h
 go/gogo-tree.o: go/gofrontend/gogo-tree.cc $(GO_SYSTEM_H) $(TOPLEV_H) \
 	$(TREE_H) $(GIMPLE_H) tree-iterator.h $(CGRAPH_H) langhooks.h \
-	convert.h output.h $(DIAGNOSTIC_H) $(RTL_H) $(GO_TYPES_H) \
+	convert.h output.h $(DIAGNOSTIC_H) $(GO_TYPES_H) \
 	$(GO_EXPRESSIONS_H) $(GO_STATEMENTS_H) $(GO_GOGO_H)
 go/gogo.o: go/gofrontend/gogo.cc $(GO_SYSTEM_H) $(GO_C_H) \
 	go/gofrontend/go-dump.h $(GO_LEX_H) $(GO_TYPES_H) $(GO_STATEMENTS_H) \
@@ -277,4 +277,5 @@ go/types.o: go/gofrontend/types.cc $(GO_SYSTEM_H) $(TOPLEV_H) intl.h $(TREE_H) \
 	$(GIMPLE_H) $(REAL_H) convert.h $(GO_C_H) $(GO_GOGO_H) \
 	go/gofrontend/operator.h $(GO_EXPRESSIONS_H) $(GO_STATEMENTS_H) \
 	go/gofrontend/export.h $(GO_IMPORT_H) $(GO_TYPES_H)
-go/unsafe.o: go/gofrontend/unsafe.cc $(GO_SYSTEM_H) $(GO_TYPES_H) $(GO_GOGO_H)
+go/unsafe.o: go/gofrontend/unsafe.cc $(GO_SYSTEM_H) $(GO_C_H) $(GO_TYPES_H) \
+	$(GO_GOGO_H)
diff --git a/gcc/go/go-backend.c b/gcc/go/go-backend.c
index 9ffe38a..5ecc99b 100644
--- a/gcc/go/go-backend.c
+++ b/gcc/go/go-backend.c
@@ -1,5 +1,5 @@
 /* go-backend.c -- Go frontend interface to gcc backend.
-   Copyright (C) 2010 Free Software Foundation, Inc.
+   Copyright (C) 2010, 2011 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -20,9 +20,11 @@ along with GCC; see the file COPYING3.  If not see
 #include "config.h"
 #include "system.h"
 #include "coretypes.h"
-#include "tree.h"
 #include "tm.h"
+#include "rtl.h"
+#include "tree.h"
 #include "tm_p.h"
+#include "target.h"
 
 #include "go-c.h"
 
@@ -70,3 +72,22 @@ go_trampoline_info (unsigned int *size, unsigned int *alignment)
   *size = TRAMPOLINE_SIZE;
   *alignment = TRAMPOLINE_ALIGNMENT;
 }
+
+/* This is called by the Go frontend proper if the unsafe package was
+   imported.  When that happens we can not do type-based alias
+   analysis.  */
+
+void
+go_imported_unsafe (void)
+{
+  flag_strict_aliasing = false;
+
+  /* This is a real hack.  init_varasm_once has already grabbed an
+     alias set, which we don't want when we aren't doing strict
+     aliasing.  We reinitialize to make it do it again.  This should
+     be OK in practice since we haven't really done anything yet.  */
+  init_varasm_once ();
+
+  /* Let the backend know that the options have changed.  */
+  targetm.override_options_after_change ();
+}
diff --git a/gcc/go/go-c.h b/gcc/go/go-c.h
index 19d5c05..a451517 100644
--- a/gcc/go/go-c.h
+++ b/gcc/go/go-c.h
@@ -1,5 +1,5 @@
 /* go-c.h -- Header file for go frontend gcc C interface.
-   Copyright (C) 2009, 2010 Free Software Foundation, Inc.
+   Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -65,6 +65,8 @@ extern unsigned int go_field_alignment (tree);
 
 extern void go_trampoline_info (unsigned int *size, unsigned int *alignment);
 
+extern void go_imported_unsafe (void);
+
 #if defined(__cplusplus) && !defined(ENABLE_BUILD_WITH_CXX)
 } /* End extern "C".  */
 #endif
diff --git a/gcc/go/gofrontend/gogo-tree.cc b/gcc/go/gofrontend/gogo-tree.cc
index bcb2519..ccd17c6 100644
--- a/gcc/go/gofrontend/gogo-tree.cc
+++ b/gcc/go/gofrontend/gogo-tree.cc
@@ -22,7 +22,6 @@ extern "C"
 #include "convert.h"
 #include "output.h"
 #include "diagnostic.h"
-#include "rtl.h"
 
 #ifndef ENABLE_BUILD_WITH_CXX
 }
@@ -810,17 +809,6 @@ Gogo::write_globals()
 
   // Pass everything back to the middle-end.
 
-  if (this->imported_unsafe_)
-    {
-      // Importing the "unsafe" package automatically disables TBAA.
-      flag_strict_aliasing = false;
-
-      // This is a real hack.  init_varasm_once has already grabbed an
-      // alias set, which we don't want when we aren't going strict
-      // aliasing.  We reinitialize to make it do it again.  FIXME.
-      init_varasm_once();
-    }
-
   wrapup_global_declarations(vec, count);
 
   cgraph_finalize_compilation_unit();
diff --git a/gcc/go/gofrontend/unsafe.cc b/gcc/go/gofrontend/unsafe.cc
index 51d812b..e219f61 100644
--- a/gcc/go/gofrontend/unsafe.cc
+++ b/gcc/go/gofrontend/unsafe.cc
@@ -6,6 +6,7 @@
 
 #include "go-system.h"
 
+#include "go-c.h"
 #include "types.h"
 #include "gogo.h"
 
@@ -130,5 +131,9 @@ Gogo::import_unsafe(const std::string& local_name, bool is_local_name_exported,
   if (add_to_globals)
     this->add_named_object(no);
 
-  this->imported_unsafe_ = true;
+  if (!this->imported_unsafe_)
+    {
+      go_imported_unsafe();
+      this->imported_unsafe_ = true;
+    }
 }