Patch: remove 2 globals from C FE

[Tom Tromey]

>>>>> "Tom" == Tom Tromey <tromey@redhat.com> writes:

Tom> Here's the first one.  This removes enum_next_value and enum_overflow
Tom> in favor of an explicitly managed state structure.

It was pointed out on irc that I cut-and-pasted the comment from
enum_next_value and (1) the old comment was grammatically incorrect,
and (2) didn't make sense in the new context anyhow.  So, I deleted a
sentence from the comment.  Here's the updated patch.

Tom

Index: ChangeLog
from  Tom Tromey  <tromey@redhat.com>

	* c-tree.h (start_enum): Update.
	(build_enumerator): Likewise.
	* c-decl.c (enum_next_value): Removed.
	(enum_overflow): Likewise.
	(start_enum): Add c_enum_contents argument.  Don't use globals.
	(build_enumerator): Likewise.
	* c-tree.h (struct c_enum_contents): New struct.

Index: c-tree.h
===================================================================
--- c-tree.h	(revision 125302)
+++ c-tree.h	(working copy)
@@ -1,6 +1,6 @@
 /* Definitions for C parsing and type checking.
    Copyright (C) 1987, 1993, 1994, 1995, 1997, 1998,
-   1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -425,6 +425,17 @@
   struct c_label_context_vm *next;
 };
 
+/* Used when parsing an enum.  Initialized by start_enum.  */
+struct c_enum_contents
+{
+  /* While defining an enum type, this is 1 plus the last enumerator
+     constant value.  */
+  tree enum_next_value;
+
+  /* Nonzero means that there was overflow computing enum_next_value.  */
+  int enum_overflow;
+};
+
 
 /* in c-parser.c */
 extern void c_parse_init (void);
@@ -448,7 +459,7 @@
 extern int quals_from_declspecs (const struct c_declspecs *);
 extern struct c_declarator *build_array_declarator (tree, struct c_declspecs *,
 						    bool, bool);
-extern tree build_enumerator (tree, tree);
+extern tree build_enumerator (struct c_enum_contents *, tree, tree);
 extern tree check_for_loop_decls (void);
 extern void mark_forward_parm_decls (void);
 extern void declare_parm_level (void);
@@ -476,7 +487,7 @@
 extern tree c_builtin_function (tree);
 extern void shadow_tag (const struct c_declspecs *);
 extern void shadow_tag_warned (const struct c_declspecs *, int);
-extern tree start_enum (tree);
+extern tree start_enum (struct c_enum_contents *, tree);
 extern int  start_function (struct c_declspecs *, struct c_declarator *, tree);
 extern tree start_decl (struct c_declarator *, struct c_declspecs *, bool,
 			tree);
Index: c-decl.c
===================================================================
--- c-decl.c	(revision 125302)
+++ c-decl.c	(working copy)
@@ -81,18 +81,6 @@
 /* True means we've initialized exception handling.  */
 bool c_eh_initialized_p;
 
-/* While defining an enum type, this is 1 plus the last enumerator
-   constant value.  Note that will do not have to save this or `enum_overflow'
-   around nested function definition since such a definition could only
-   occur in an enum value expression and we don't use these variables in
-   that case.  */
-
-static tree enum_next_value;
-
-/* Nonzero means that there was overflow computing enum_next_value.  */
-
-static int enum_overflow;
-
 /* The file and line that the prototype came from if this is an
    old-style definition; used for diagnostics in
    store_parm_decls_oldstyle.  */
@@ -5801,7 +5789,7 @@
    may be used to declare the individual values as they are read.  */
 
 tree
-start_enum (tree name)
+start_enum (struct c_enum_contents *the_enum, tree name)
 {
   tree enumtype = 0;
 
@@ -5833,8 +5821,8 @@
       TYPE_VALUES (enumtype) = 0;
     }
 
-  enum_next_value = integer_zero_node;
-  enum_overflow = 0;
+  the_enum->enum_next_value = integer_zero_node;
+  the_enum->enum_overflow = 0;
 
   if (flag_short_enums)
     TYPE_PACKED (enumtype) = 1;
@@ -5987,7 +5975,7 @@
    Assignment of sequential values by default is handled here.  */
 
 tree
-build_enumerator (tree name, tree value)
+build_enumerator (struct c_enum_contents *the_enum, tree name, tree value)
 {
   tree decl, type;
 
@@ -6017,8 +6005,8 @@
      in the default.  */
   if (value == 0)
     {
-      value = enum_next_value;
-      if (enum_overflow)
+      value = the_enum->enum_next_value;
+      if (the_enum->enum_overflow)
 	error ("overflow in enumeration values");
     }
 
@@ -6031,8 +6019,9 @@
     }
 
   /* Set basis for default for next value.  */
-  enum_next_value = build_binary_op (PLUS_EXPR, value, integer_one_node, 0);
-  enum_overflow = tree_int_cst_lt (enum_next_value, value);
+  the_enum->enum_next_value = build_binary_op (PLUS_EXPR, value,
+					       integer_one_node, 0);
+  the_enum->enum_overflow = tree_int_cst_lt (the_enum->enum_next_value, value);
 
   /* Now create a declaration for the enum value name.  */
 
Index: c-parser.c
===================================================================
--- c-parser.c	(revision 125302)
+++ c-parser.c	(working copy)
@@ -1,6 +1,6 @@
 /* Parser for C and Objective-C.
    Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
 
    Parser actions based on the old Bison parser; structure somewhat
    influenced by and fragments based on the C++ parser.
@@ -1698,7 +1698,8 @@
   if (c_parser_next_token_is (parser, CPP_OPEN_BRACE))
     {
       /* Parse an enum definition.  */
-      tree type = start_enum (ident);
+      struct c_enum_contents the_enum;
+      tree type = start_enum (&the_enum, ident);
       tree postfix_attrs;
       /* We chain the enumerators in reverse order, then put them in
 	 forward order at the end.  */
@@ -1726,7 +1727,7 @@
 	    }
 	  else
 	    enum_value = NULL_TREE;
-	  enum_decl = build_enumerator (enum_id, enum_value);
+	  enum_decl = build_enumerator (&the_enum, enum_id, enum_value);
 	  TREE_CHAIN (enum_decl) = values;
 	  values = enum_decl;
 	  seen_comma = false;