params.def (PARAM_VERIFY_CANONICAL_TYPES): Remove.

2007-07-11  Douglas Gregor  <doug.gregor@gmail.com>

       * params.def (PARAM_VERIFY_CANONICAL_TYPES): Remove.
       (PARAM_USE_CANONICAL_TYPES): New; decides whether to use canonical
       types or not.
       * params.h (VERIFY_CANONICAL_TYPES): Remove.
       (USE_CANONICAL_TYPES): New.
       * doc/invoke.texi (verify-canonical-types): Remove.
       (use-canonical-types): Add.

2007-07-11  Douglas Gregor  <doug.gregor@gmail.com>

       * typeck.c (comptypes): When USE_CANONICAL_TYPES, use the
       canonical types; otherwise, fall back to structural type
       comparisons. If ENABLE_CHECKING and USE_CANONICAL_TYPES, give an
       internal compiler error if the canonical types are wrong.

From-SVN: r126550

6 files changed, 56 insertions, 47 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a90b025e2d8..4a01bbe04c8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2007-07-11  Douglas Gregor  <doug.gregor@gmail.com>
+
+	* params.def (PARAM_VERIFY_CANONICAL_TYPES): Remove.
+	(PARAM_USE_CANONICAL_TYPES): New; decides whether to use canonical 
+	types or not.
+	* params.h (VERIFY_CANONICAL_TYPES): Remove.
+	(USE_CANONICAL_TYPES): New.
+	* doc/invoke.texi (verify-canonical-types): Remove.
+	(use-canonical-types): Add.
+	
 2007-07-11  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	* config/spu/spu.c (spu_optimization_options): Remove setting of
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 3ffc400c1cb..8165176ae5e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2007-07-11  Douglas Gregor  <doug.gregor@gmail.com>
+
+	* typeck.c (comptypes): When USE_CANONICAL_TYPES, use the
+	canonical types; otherwise, fall back to structural type
+	comparisons. If ENABLE_CHECKING and USE_CANONICAL_TYPES, give an
+	internal compiler error if the canonical types are wrong.
+	
 2007-07-11  Paolo Carlini  <pcarlini@suse.de>
 
 	PR c++/32560
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 3b8b914864e..4f08c8e9aa7 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -1108,8 +1108,6 @@ comptypes (tree t1, tree t2, int strict)
 {
   if (strict == COMPARE_STRICT)
     {
-      bool result;
-
       if (t1 == t2)
 	return true;
 
@@ -1121,37 +1119,34 @@ comptypes (tree t1, tree t2, int strict)
 	   perform a deep check. */
 	return structural_comptypes (t1, t2, strict);
 
-      if (VERIFY_CANONICAL_TYPES)
+#ifdef ENABLE_CHECKING
+      if (USE_CANONICAL_TYPES)
 	{
-	  result = structural_comptypes (t1, t2, strict);
-
+	  bool result = structural_comptypes (t1, t2, strict);
+	  
 	  if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
-	    {
-	      /* The two types are structurally equivalent, but their
-		 canonical types were different. This is a failure of the
-		 canonical type propagation code.*/
-	      warning(0,
-		      "canonical types differ for identical types %T and %T", 
-		      t1, t2);
-	      debug_tree (t1);
-	      debug_tree (t2);
-	    }
+	    /* The two types are structurally equivalent, but their
+	       canonical types were different. This is a failure of the
+	       canonical type propagation code.*/
+	    internal_error 
+	      ("canonical types differ for identical types %T and %T", 
+	       t1, t2);
 	  else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
-	    {
-	      /* Two types are structurally different, but the canonical
-		 types are the same. This means we were over-eager in
-		 assigning canonical types. */
-	      warning (0, 
-		       "same canonical type node for different types %T and %T",
-		       t1, t2);
-	      debug_tree (t1);
-	      debug_tree (t2);
-	    }
+	    /* Two types are structurally different, but the canonical
+	       types are the same. This means we were over-eager in
+	       assigning canonical types. */
+	    internal_error 
+	      ("same canonical type node for different types %T and %T",
+	       t1, t2);
 	  
 	  return result;
 	}
-      else
+#else
+      if (USE_CANONICAL_TYPES)
 	return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
+#endif
+      else
+	return structural_comptypes (t1, t2, strict);
     }
   else if (strict == COMPARE_STRUCTURAL)
     return structural_comptypes (t1, t2, COMPARE_STRICT);
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 6a4bc299c2a..c954b9fe9d5 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -6960,12 +6960,12 @@ The size of cache line in L1 cache, in bytes.
 @item l1-cache-size
 The number of cache lines in L1 cache.
 
-@item verify-canonical-types
-Whether the compiler should verify the ``canonical'' types used for
-type equality comparisons within the C++ and Objective-C++ front
-ends. Set to 1 (the default when GCC is configured with
---enable-checking) to enable verification, 0 to disable verification
-(the default when GCC is configured with --disable-checking).
+@item use-canonical-types
+Whether the compiler should use the ``canonical'' type system.  By
+default, this should always be 1, which uses a more efficient internal
+mechanism for comparing types in C++ and Objective-C++.  However, if
+bugs in the canonical type system are causing compilation failures,
+set this value to 0 to disable canonical types.
 
 @end table
 @end table
diff --git a/gcc/params.def b/gcc/params.def
index 70ca3ad00c1..c9d5b8084dd 100644
--- a/gcc/params.def
+++ b/gcc/params.def
@@ -673,19 +673,16 @@ DEFPARAM (PARAM_L1_CACHE_LINE_SIZE,
 	  "The size of L1 cache line",
 	  32, 0, 0)
 
-#ifdef ENABLE_CHECKING
-# define GCC_CANONICAL_TYPES_DEFAULT 1
-#else
-# define GCC_CANONICAL_TYPES_DEFAULT 0
-#endif
-
-/* Whether we should verify that the canonical types in the system are
-   consistent with the "structural" typing. */
-
-DEFPARAM (PARAM_VERIFY_CANONICAL_TYPES,
-	  "verify-canonical-types",
-	  "Whether to verify canonical types",
-	  GCC_CANONICAL_TYPES_DEFAULT, 0, 1)
+/* Whether we should use canonical types rather than deep "structural"
+   type checking.  Setting this value to 1 (the default) improves
+   compilation performance in the C++ and Objective-C++ front end;
+   this value should only be set to zero to work around bugs in the
+   canonical type system by disabling it.  */
+
+DEFPARAM (PARAM_USE_CANONICAL_TYPES,
+	  "use-canonical-types",
+	  "Whether to use canonical types",
+	  1, 0, 1)
 /*
 Local variables:
 mode:c
diff --git a/gcc/params.h b/gcc/params.h
index 386e781c26a..410ae335fe4 100644
--- a/gcc/params.h
+++ b/gcc/params.h
@@ -168,6 +168,6 @@ typedef enum compiler_param
   PARAM_VALUE (PARAM_L1_CACHE_SIZE)
 #define L1_CACHE_LINE_SIZE \
   PARAM_VALUE (PARAM_L1_CACHE_LINE_SIZE)
-#define VERIFY_CANONICAL_TYPES \
-  PARAM_VALUE (PARAM_VERIFY_CANONICAL_TYPES)
+#define USE_CANONICAL_TYPES \
+  PARAM_VALUE (PARAM_USE_CANONICAL_TYPES)
 #endif /* ! GCC_PARAMS_H */