c-decl.c (start_decl): Unconditionally issue error for 'typedef foo = bar'.

gcc:
	* c-decl.c (start_decl): Unconditionally issue error for
	'typedef foo = bar'.
	(finish_decl): Remove special case for TYPE_DECL with initializer.

	* doc/extend.texi: Delete "Naming Types" section.  Change all
	cross-references to that section to refer to "Typeof" instead.
	Add the useful safe-max()-macro example from "Naming Types" to
	"Typeof", rewritten using that extension.

gcc/cp:
	* decl.c (start_decl): Unconditionally issue error for
	'typedef foo = bar'.
	(cp_finish_decl): Remove special case for TYPE_DECL with initializer.
	(grokdeclarator): Remove redundant error for 'typedef foo = bar'.

gcc/testsuite:
	* g++.dg/ext/typedef-init.C: New test.
	* gcc.dg/typedef-init.c: New test.

From-SVN: r57995

8 files changed, 101 insertions, 73 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c2bdf92..fbe859a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,16 @@
+2002-10-09  Zack Weinberg  <zack@codesourcery.com>
+
+	PR c/7353
+	* c-decl.c (start_decl): Unconditionally issue error for
+	'typedef foo = bar'.
+	(finish_decl): Remove special case for TYPE_DECL with initializer.
+
+	* doc/extend.texi: Delete "Naming Types" section.  Change all
+	cross-references to that section to refer to "Typeof" instead.
+	Add the useful safe-max()-macro example from "Naming Types" to
+	"Typeof", rewritten using that extension.  Add some compatibility
+	notes to "Typeof."
+
 2002-10-09  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* loop.c: Revert 2002-08-15 change.
diff --git a/gcc/c-decl.c b/gcc/c-decl.c
index dba2737..60fade4 100644
--- a/gcc/c-decl.c
+++ b/gcc/c-decl.c
@@ -2821,15 +2821,9 @@ start_decl (declarator, declspecs, initialized, attributes)
     switch (TREE_CODE (decl))
       {
       case TYPE_DECL:
-	/* typedef foo = bar  means give foo the same type as bar.
-	   We haven't parsed bar yet, so `finish_decl' will fix that up.
-	   Any other case of an initialization in a TYPE_DECL is an error.  */
-	if (pedantic || list_length (declspecs) > 1)
-	  {
-	    error ("typedef `%s' is initialized",
-		   IDENTIFIER_POINTER (DECL_NAME (decl)));
-	    initialized = 0;
-	  }
+	error ("typedef `%s' is initialized",
+	       IDENTIFIER_POINTER (DECL_NAME (decl)));
+	initialized = 0;
 	break;
 
       case FUNCTION_DECL:
@@ -2988,16 +2982,7 @@ finish_decl (decl, init, asmspec_tree)
     init = 0;
 
   if (init)
-    {
-      if (TREE_CODE (decl) != TYPE_DECL)
-	store_init_value (decl, init);
-      else
-	{
-	  /* typedef foo = bar; store the type of bar as the type of foo.  */
-	  TREE_TYPE (decl) = TREE_TYPE (init);
-	  DECL_INITIAL (decl) = init = 0;
-	}
-    }
+    store_init_value (decl, init);
 
   /* Deduce size of array from initialization, if not already known */
   if (TREE_CODE (type) == ARRAY_TYPE
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 49d65cd..edb8694 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2002-10-09  Zack Weinberg  <zack@codesourcery.com>
+
+	* decl.c (start_decl): Unconditionally issue error for
+	'typedef foo = bar'.
+	(cp_finish_decl): Remove special case for TYPE_DECL with initializer.
+	(grokdeclarator): Remove redundant error for 'typedef foo = bar'.
+
 2002-10-09  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* decl2.c (prune_vtable_vardecl): Delete unused function.
@@ -84,7 +91,7 @@
 2002-10-02  Matt Austern  <austern@apple.com>
 	* decl.c (walk_vtables_r): Fixed typo that caused result to
 	never get a nonzero value.
-	
+
 2002-10-02  Roger Sayle  <roger@eyesopen.com>
 
 	PR optimization/6627
@@ -98,7 +105,7 @@
 
 	* class.c (check_field_decls): Changed warning about const member
 	variables so that it doesn't get issued for a class aggregate.
-	
+
 2002-10-01  Mark Mitchell  <mark@codesourcery.com>
 
 	* decl.c (cp_finish_decl): Make sure array types are laid out,
@@ -181,12 +188,12 @@
 	(dfs_unuse_fields): Likewise.
 	* tree.c (pod_type_p): Handle error_mark_node.
 	(zero_init_p): Likewise.
-	* typeck.c (lookup_anon_field): Skip FIELD_DECLs for base 
+	* typeck.c (lookup_anon_field): Skip FIELD_DECLs for base
 	subobjects.
 	* typeck2.c (store_init_value): Remove #if 0'd code.
 	(force_store_init_value): Remove.
 	(process_init_constructor): Use build_zero_init.
-	
+
 2002-09-29  Nathan Sidwell  <nathan@codesourcery.com>
 
 	PR c++/7788
@@ -214,7 +221,7 @@
 	even number of bytes when computing the size without virtual
 	bases.
 	* cp/cp-tree.h (abi_version_at_least): New macro.
-	
+
 2002-09-21  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* ChangeLog: Follow spelling conventions.
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index e095f07..8ab8a5e 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7290,14 +7290,8 @@ start_decl (declarator, declspecs, initialized, attributes, prefix_attributes)
     switch (TREE_CODE (decl))
       {
       case TYPE_DECL:
-	/* typedef foo = bar  means give foo the same type as bar.
-	   We haven't parsed bar yet, so `cp_finish_decl' will fix that up.
-	   Any other case of an initialization in a TYPE_DECL is an error.  */
-	if (pedantic || list_length (declspecs) > 1)
-	  {
-	    error ("typedef `%D' is initialized", decl);
-	    initialized = 0;
-	  }
+	error ("typedef `%D' is initialized", decl);
+	initialized = 0;
 	break;
 
       case FUNCTION_DECL:
@@ -8156,12 +8150,6 @@ cp_finish_decl (decl, init, asmspec_tree, flags)
   /* Take care of TYPE_DECLs up front.  */
   if (TREE_CODE (decl) == TYPE_DECL)
     {
-      if (init && DECL_INITIAL (decl))
-	{
-	  /* typedef foo = bar; store the type of bar as the type of foo.  */
-	  TREE_TYPE (decl) = type = TREE_TYPE (init);
-	  DECL_INITIAL (decl) = init = NULL_TREE;
-	}
       if (type != error_mark_node
 	  && IS_AGGR_TYPE (type) && DECL_NAME (decl))
 	{
@@ -11365,9 +11353,6 @@ grokdeclarator (declarator, declspecs, decl_context, initialized, attrlist)
       bad_specifiers (decl, "type", virtualp, quals != NULL_TREE,
 		      inlinep, friendp, raises != NULL_TREE);
 
-      if (initialized)
-	error ("typedef declaration includes an initializer");
-
       return decl;
     }
 
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index a95098f..f583a67 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -427,7 +427,6 @@ extensions, accepted by GCC in C89 mode and in C++.
 * Labels as Values::    Getting pointers to labels, and computed gotos.
 * Nested Functions::    As in Algol and Pascal, lexical scoping of functions.
 * Constructing Calls::	Dispatching a call to another function.
-* Naming Types::        Giving a name to the type of some expression.
 * Typeof::              @code{typeof}: referring to the type of an expression.
 * Lvalues::             Using @samp{?:}, @samp{,} and casts in lvalues.
 * Conditionals::        Omitting the middle operand of a @samp{?:} expression.
@@ -538,8 +537,7 @@ the value of an enumeration constant, the width of a bit-field, or
 the initial value of a static variable.
 
 If you don't know the type of the operand, you can still do this, but you
-must use @code{typeof} (@pxref{Typeof}) or type naming (@pxref{Naming
-Types}).
+must use @code{typeof} (@pxref{Typeof}).
 
 Statement expressions are not supported fully in G++, and their fate
 there is unclear.  (It is possible that they will become fully supported
@@ -888,29 +886,6 @@ the containing function.  You should specify, for @var{result}, a value
 returned by @code{__builtin_apply}.
 @end deftypefn
 
-@node Naming Types
-@section Naming an Expression's Type
-@cindex naming types
-
-You can give a name to the type of an expression using a @code{typedef}
-declaration with an initializer.  Here is how to define @var{name} as a
-type name for the type of @var{exp}:
-
-@example
-typedef @var{name} = @var{exp};
-@end example
-
-This is useful in conjunction with the statements-within-expressions
-feature.  Here is how the two together can be used to define a safe
-``maximum'' macro that operates on any arithmetic type:
-
-@example
-#define max(a,b) \
-  (@{typedef _ta = (a), _tb = (b);  \
-    _ta _a = (a); _tb _b = (b);     \
-    _a > _b ? _a : _b; @})
-@end example
-
 @cindex underscores in variables in macros
 @cindex @samp{_} in variables in macros
 @cindex local variables in macros
@@ -962,6 +937,21 @@ A @code{typeof}-construct can be used anywhere a typedef name could be
 used.  For example, you can use it in a declaration, in a cast, or inside
 of @code{sizeof} or @code{typeof}.
 
+@code{typeof} is often useful in conjunction with the
+statements-within-expressions feature.  Here is how the two together can
+be used to define a safe ``maximum'' macro that operates on any
+arithmetic type and evaluates each of its arguments exactly once:
+
+@example
+#define max(a,b) \
+  (@{ typeof (a) _a = (a); \
+      typeof (b) _b = (b); \
+    _a > _b ? _a : _b; @})
+@end example
+
+@noindent
+Some more examples of the use of @code{typeof}:
+
 @itemize @bullet
 @item
 This declares @code{y} with the type of what @code{x} points to.
@@ -1011,6 +1001,26 @@ Thus, @code{array (pointer (char), 4)} is the type of arrays of 4
 pointers to @code{char}.
 @end itemize
 
+@emph{Compatibility Note:} In addition to @code{typeof}, GCC 2 supported
+a more limited extension which permitted one to write
+
+@example
+typedef @var{T} = @var{expr};
+@end example
+
+@noindent
+with the effect of declaring @var{T} to have the type of the expression
+@var{expr}.  This extension does not work with GCC 3 (versions between
+3.0 and 3.2 will crash; 3.2.1 and later give an error).  Code which
+relies on it should be rewritten to use @code{typeof}:
+
+@example
+typedef typeof(@var{expr}) @var{T};
+@end example
+
+@noindent
+This will work with all versions of GCC@.
+
 @node Lvalues
 @section Generalized Lvalues
 @cindex compound expressions as lvalues
@@ -6827,12 +6837,12 @@ the minimum value of variables @var{i} and @var{j}.
 
 However, side effects in @code{X} or @code{Y} may cause unintended
 behavior.  For example, @code{MIN (i++, j++)} will fail, incrementing
-the smaller counter twice.  A GNU C extension allows you to write safe
-macros that avoid this kind of problem (@pxref{Naming Types,,Naming an
-Expression's Type}).  However, writing @code{MIN} and @code{MAX} as
-macros also forces you to use function-call notation for a
-fundamental arithmetic operation.  Using GNU C++ extensions, you can
-write @w{@samp{int min = i <? j;}} instead.
+the smaller counter twice.  The GNU C @code{typeof} extension allows you
+to write safe macros that avoid this kind of problem (@pxref{Typeof}).
+However, writing @code{MIN} and @code{MAX} as macros also forces you to
+use function-call notation for a fundamental arithmetic operation.
+Using GNU C++ extensions, you can write @w{@samp{int min = i <? j;}}
+instead.
 
 Since @code{<?} and @code{>?} are built into the compiler, they properly
 handle expressions with side-effects;  @w{@samp{int min = i++ <? j++;}}
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f51687f..f3122fd 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2002-10-09  Zack Weinberg  <zack@codesourcery.com>
+
+	* g++.dg/ext/typedef-init.C: New test.
+	* gcc.dg/typedef-init.c: New test.
+
 2002-10-09  Neil Booth  <neil@daikokuya.co.uk>
 
 	* gcc.dg/cpp/paste13.c: New test.
diff --git a/gcc/testsuite/g++.dg/ext/typedef-init.C b/gcc/testsuite/g++.dg/ext/typedef-init.C
new file mode 100644
index 0000000..5602783
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/typedef-init.C
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-fpermissive" } // suppress default -pedantic-errors */
+
+/* This code used to be a legitimate, if dubious, extension.  However,
+   it's been broken since GCC 3.0 (caused ICE) and we have now removed
+   the extension.  See PR c/7353.
+
+   C++ issues a warning in addition to the error, since this construct
+   appears to be a case of implicit int (forbidden in std. C++) until
+   we get to the equals sign.  */
+
+typedef A = 0;  /* { dg-error "initialized" "typedef A = B" } */
+                /* { dg-warning "no type" "also warns" { target *-*-* } 12 } */
+A a;            /* { dg-bogus "" "no error cascade" } */
diff --git a/gcc/testsuite/gcc.dg/typedef-init.c b/gcc/testsuite/gcc.dg/typedef-init.c
new file mode 100644
index 0000000..9cb4830b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/typedef-init.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu89" } // suppress default -pedantic-errors */
+
+/* This code used to be a legitimate, if dubious, extension.  However,
+   it's been broken since GCC 3.0 (caused ICE) and we have now removed
+   the extension.  See PR c/7353.  */
+
+typedef A = 0;  /* { dg-error "initialized" "typedef A = B" } */
+A a;            /* { dg-bogus "" "no error cascade" } */