[PATCH][all-langs] Defer size_t and sizetype setting to the middle-end

[Richard Guenther <rguenther at suse dot de>]

This patch defers the control over size_t and sizetype to the
middle-end which in turn consults the target.  This removes
various inconsistencies for frontends that do not seem to care
about size_t and will allow simplifying the global tree initialization.

Bootstrapped on x86_64-unknown-linux-gnu for all languages, testing
in progress.

Ok for trunk?  (the change is worthwhile from an LTO and middle-end
perspective and I'll apply leeway to frontends that appear to be
unmaintained - hello Java)

Thanks,
Richard.

2011-06-01  Richard Guenther  <rguenther@suse.de>

	* tree.c (build_common_tree_nodes): Also initialize size_type_node.
	Call set_sizetype from here.

	c-family/
	* c-common.c (c_common_nodes_and_builtins): Do not set
	size_type_node or call set_sizetype.

	go/
	* go-lang.c (go_langhook_init): Do not set
	size_type_node or call set_sizetype.

	fortran/
	* f95-lang.c (gfc_init_decl_processing): Do not set
	size_type_node or call set_sizetype.

	java/
	* decl.c (java_init_decl_processing): Properly initialize
	size_type_node.

	lto/
	* lto-lang.c (lto_init): Do not set
	size_type_node or call set_sizetype.

	ada/
	* gcc-interface/misc.c (gnat_init): Do not set
	size_type_node or call set_sizetype.

Index: gcc/tree.c
===================================================================
--- gcc/tree.c	(revision 174520)
+++ gcc/tree.c	(working copy)
@@ -9142,6 +9142,7 @@ build_common_tree_nodes (bool signed_cha
         int128_unsigned_type_node = make_unsigned_type (128);
       }
 #endif
+
   /* Define a boolean type.  This type only represents boolean values but
      may be larger than char depending on the value of BOOL_TYPE_SIZE.
      Front ends which want to override this size (i.e. Java) can redefine
@@ -9151,6 +9152,17 @@ build_common_tree_nodes (bool signed_cha
   TYPE_MAX_VALUE (boolean_type_node) = build_int_cst (boolean_type_node, 1);
   TYPE_PRECISION (boolean_type_node) = 1;
 
+  /* Define what type to use for size_t.  */
+  if (strcmp (SIZE_TYPE, "unsigned int") == 0)
+    size_type_node = unsigned_type_node;
+  else if (strcmp (SIZE_TYPE, "long unsigned int") == 0)
+    size_type_node = long_unsigned_type_node;
+  else if (strcmp (SIZE_TYPE, "long long unsigned int") == 0)
+    size_type_node = long_long_unsigned_type_node;
+  else
+    gcc_unreachable ();
+  set_sizetype (size_type_node);
+
   /* Fill in the rest of the sized types.  Reuse existing type nodes
      when possible.  */
   intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 0);
Index: gcc/c-family/c-common.c
===================================================================
--- gcc/c-family/c-common.c	(revision 174520)
+++ gcc/c-family/c-common.c	(working copy)
@@ -4666,13 +4666,7 @@ c_common_nodes_and_builtins (void)
 					 TYPE_DECL, NULL_TREE,
 					 widest_unsigned_literal_type_node));
 
-  /* `unsigned long' is the standard type for sizeof.
-     Note that stddef.h uses `unsigned long',
-     and this must agree, even if long and int are the same size.  */
-  size_type_node =
-    TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE)));
   signed_size_type_node = c_common_signed_type (size_type_node);
-  set_sizetype (size_type_node);
 
   pid_type_node =
     TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE)));
Index: gcc/go/go-lang.c
===================================================================
--- gcc/go/go-lang.c	(revision 174520)
+++ gcc/go/go-lang.c	(working copy)
@@ -87,15 +87,6 @@ go_langhook_init (void)
 {
   build_common_tree_nodes (false);
 
-  /* The sizetype may be "unsigned long" or "unsigned long long".  */
-  if (TYPE_MODE (long_unsigned_type_node) == ptr_mode)
-    size_type_node = long_unsigned_type_node;
-  else if (TYPE_MODE (long_long_unsigned_type_node) == ptr_mode)
-    size_type_node = long_long_unsigned_type_node;
-  else
-    size_type_node = long_unsigned_type_node;
-  set_sizetype (size_type_node);
-
   build_common_tree_nodes_2 (0);
 
   /* We must create the gogo IR after calling build_common_tree_nodes
Index: gcc/fortran/f95-lang.c
===================================================================
--- gcc/fortran/f95-lang.c	(revision 174520)
+++ gcc/fortran/f95-lang.c	(working copy)
@@ -590,9 +590,6 @@ gfc_init_decl_processing (void)
      want double_type_node to actually have double precision.  */
   build_common_tree_nodes (false);
 
-  size_type_node = gfc_build_uint_type (POINTER_SIZE);
-  set_sizetype (size_type_node);
-
   build_common_tree_nodes_2 (0);
   void_list_node = build_tree_list (NULL_TREE, void_type_node);
 
Index: gcc/java/decl.c
===================================================================
--- gcc/java/decl.c	(revision 174520)
+++ gcc/java/decl.c	(working copy)
@@ -606,7 +606,14 @@ java_init_decl_processing (void)
 
   /* This is not a java type, however tree-dfa requires a definition for
      size_type_node.  */
-  size_type_node = make_unsigned_type (POINTER_SIZE);
+  if (strcmp (SIZE_TYPE, "unsigned int") == 0)
+    size_type_node = make_unsigned_type (INT_TYPE_SIZE);
+  else if (strcmp (SIZE_TYPE, "long unsigned int") == 0)
+    size_type_node = make_unsigned_type (LONG_TYPE_SIZE);
+  else if (strcmp (SIZE_TYPE, "long long unsigned int") == 0)
+    size_type_node = make_unsigned_type (LONG_LONG_TYPE_SIZE);
+  else
+    gcc_unreachable ();
   set_sizetype (size_type_node);
 
   /* Define these next since types below may used them.  */
Index: gcc/lto/lto-lang.c
===================================================================
--- gcc/lto/lto-lang.c	(revision 174520)
+++ gcc/lto/lto-lang.c	(working copy)
@@ -1087,17 +1087,6 @@ lto_init (void)
   /* Create the basic integer types.  */
   build_common_tree_nodes (flag_signed_char);
 
-  /* Tell the middle end what type to use for the size of objects.  */
-  if (strcmp (SIZE_TYPE, "unsigned int") == 0)
-    size_type_node = unsigned_type_node;
-  else if (strcmp (SIZE_TYPE, "long unsigned int") == 0)
-    size_type_node = long_unsigned_type_node;
-  else if (strcmp (SIZE_TYPE, "long long unsigned int") == 0)
-    size_type_node = long_long_unsigned_type_node;
-  else
-    gcc_unreachable ();
-  set_sizetype (size_type_node);
-
   /* The global tree for the main identifier is filled in by
      language-specific front-end initialization that is not run in the
      LTO back-end.  It appears that all languages that perform such
Index: gcc/ada/gcc-interface/misc.c
===================================================================
--- gcc/ada/gcc-interface/misc.c	(revision 174520)
+++ gcc/ada/gcc-interface/misc.c	(working copy)
@@ -309,17 +309,6 @@ gnat_init (void)
      matter since we'll use the explicit `unsigned char' for Character.  */
   build_common_tree_nodes (flag_signed_char);
 
-  /* In Ada, we use the unsigned type corresponding to the width of Pmode as
-     SIZETYPE.  In most cases when ptr_mode and Pmode differ, C will use the
-     width of ptr_mode for SIZETYPE, but we get better code using the width
-     of Pmode.  Note that, although we manipulate negative offsets for some
-     internal constructs and rely on compile time overflow detection in size
-     computations, using unsigned types for SIZETYPEs is fine since they are
-     treated specially by the middle-end, in particular sign-extended.  */
-  size_type_node = gnat_type_for_mode (Pmode, 1);
-  set_sizetype (size_type_node);
-  TYPE_NAME (sizetype) = get_identifier ("size_type");
-
   /* In Ada, we use an unsigned 8-bit type for the default boolean type.  */
   boolean_type_node = make_unsigned_type (8);
   TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);