Remap dynamic cast hint values to be consistent across ABIs.

	* search.c (dynamic_cast_base_recurse): Remap generated value.
	(get_dynamic_cast_base_type): Adjust documentation.
	* tinfo.h (__user_type_info::dyncast): Likewise.
	(__user_type_info::find_public_subobj): Remap BOFF meaning.
	* tinfo.cc (__si_type_info::do_dyncast): Remap BOFF meaning.
	(__class_type_info::do_dyncast): Likewise.
	(__class_type_info::do_find_public_subobj): Likewise.
	* tinfo2.cc (__dynamic_cast): Remap BOFF parameter.

From-SVN: r31538

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index c123e53..074c0b0 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,15 @@
+2000-01-20  Nathan Sidwell  <sidwell@codesourcery.com>
+
+       Remap dynamic cast hint values to be consistent across ABIs.
+       * search.c (dynamic_cast_base_recurse): Remap generated value.
+       (get_dynamic_cast_base_type): Adjust documentation.
+       * tinfo.h (__user_type_info::dyncast): Likewise.
+       (__user_type_info::find_public_subobj): Remap BOFF meaning.
+       * tinfo.cc (__si_type_info::do_dyncast): Remap BOFF meaning.
+       (__class_type_info::do_dyncast): Likewise.
+       (__class_type_info::do_find_public_subobj): Likewise.
+       * tinfo2.cc (__dynamic_cast): Remap BOFF parameter.     
+
 2000-01-19  Gabriel Dos Reis  <gdr@codesourcery.coom>
 
         * typeck.c (build_unary_op): Use cp_pedwarn, not pedwarn.

diff --git a/gcc/cp/search.c b/gcc/cp/search.c
index d29cdb5..390c974 100644 (file)
--- a/gcc/cp/search.c
+++ b/gcc/cp/search.c
@@ -503,12 +503,12 @@ dynamic_cast_base_recurse (subtype, binfo, via_virtual, offset_ptr)
 {
   tree binfos;
   int i, n_baselinks;
-  int worst = -3;
+  int worst = -2;
   
   if (BINFO_TYPE (binfo) == subtype)
     {
       if (via_virtual)
-        return -2;
+        return -1;
       else
         {
           *offset_ptr = BINFO_OFFSET (binfo);
@@ -528,26 +528,28 @@ dynamic_cast_base_recurse (subtype, binfo, via_virtual, offset_ptr)
       rval = dynamic_cast_base_recurse
              (subtype, base_binfo,
               via_virtual || TREE_VIA_VIRTUAL (base_binfo), offset_ptr);
-      if (worst == -3)
+      if (worst == -2)
         worst = rval;
       else if (rval >= 0)
-        worst = worst >= 0 ? -1 : worst;
-      else if (rval > -3)
-        worst = worst < rval ? worst : rval;
+        worst = worst >= 0 ? -3 : worst;
+      else if (rval == -1)
+        worst = -1;
+      else if (rval == -3 && worst != -1)
+        worst = -3;
     }
   return worst;
 }
 
-/* The dynamic cast runtime needs a hint about how the static SUBTYPE type started
-   from is related to the required TARGET type, in order to optimize the
-   inheritance graph search. This information is independant of the
+/* The dynamic cast runtime needs a hint about how the static SUBTYPE type
+   started from is related to the required TARGET type, in order to optimize
+   the inheritance graph search. This information is independant of the
    current context, and ignores private paths, hence get_base_distance is
    inappropriate. Return a TREE specifying the base offset, BOFF.
    BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
       and there are no public virtual SUBTYPE bases.
-   BOFF == -1, SUBTYPE occurs as multiple public non-virtual bases.
-   BOFF == -2, SUBTYPE occurs as multiple public virtual or non-virtual bases.
-   BOFF == -3, SUBTYPE is not a public base.  */
+   BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
+   BOFF == -2, SUBTYPE is not a public base.
+   BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases.  */
 
 tree
 get_dynamic_cast_base_type (subtype, target)

diff --git a/gcc/cp/tinfo.cc b/gcc/cp/tinfo.cc
index 18a00b0..1ad5840 100644 (file)
--- a/gcc/cp/tinfo.cc
+++ b/gcc/cp/tinfo.cc
@@ -243,7 +243,7 @@ do_dyncast (int boff, sub_kind access_path,
       if (boff >= 0)
         result.target2sub = ((char *)subptr - (char *)objptr) == boff
               ? contained_public : not_contained;
-      else if (boff == -3)
+      else if (boff == -2)
         result.target2sub = not_contained;
       return false;
     }
@@ -361,7 +361,7 @@ do_dyncast (int boff, sub_kind access_path,
       if (boff >= 0)
         result.target2sub = ((char *)subptr - (char *)objptr) == boff
               ? contained_public : not_contained;
-      else if (boff == -3)
+      else if (boff == -2)
         result.target2sub = not_contained;
       return false;
     }
@@ -519,7 +519,7 @@ do_find_public_subobj (int boff, const type_info &subtype, void *objptr, void *s
         continue; // Not public, can't be here.
       void *p;
 
-      if (base_list[i].is_virtual && boff == -1)
+      if (base_list[i].is_virtual && boff == -3)
        // Not a virtual base, so can't be here.
        continue;
       

diff --git a/gcc/cp/tinfo.h b/gcc/cp/tinfo.h
index 116c7a8..91d52bd 100644 (file)
--- a/gcc/cp/tinfo.h
+++ b/gcc/cp/tinfo.h
@@ -24,12 +24,12 @@ struct __user_type_info : public std::type_info {
   // BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset
   //    BOFF, and there are no public virtual SUBTYPE bases.
   //    Therefore check if SUBOBJ is at offset BOFF when we find a target
-  // BOFF == -1, SUBTYPE occurs as multiple public non-virtual bases.
-  //    Lazily search the non-virtual bases of TARGET.
-  // BOFF == -2, SUBTYPE occurs as multiple public virtual or non-virtual bases.
+  // BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
   //    Lazily search all the bases of TARGET.
-  // BOFF == -3, SUBTYPE is not a public base.
-  // For backwards compatibility set BOFF to -2, that is the safe `don't know'
+  // BOFF == -2, SUBTYPE is not a public base.
+  // BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases.
+  //    Lazily search the non-virtual bases of TARGET.
+  // For backwards compatibility set BOFF to -1, that is the safe `don't know'
   // value. We don't care about SUBTYPES as private bases of TARGET, as they
   // can never succeed as downcasts, only as crosscasts -- and then only if
   // they are virtual. This is more complicated that it might seem.
@@ -131,7 +131,7 @@ struct __user_type_info : public std::type_info {
     if (boff >= 0)
       return ((char *)subptr - (char *)objptr) == boff
               ? contained_public : not_contained;
-    if (boff == -3)
+    if (boff == -2)
       return not_contained;
     return do_find_public_subobj (boff, subtype, objptr, subptr);
   }

diff --git a/gcc/cp/tinfo2.cc b/gcc/cp/tinfo2.cc
index f24b59b..f1b9d92 100644 (file)
--- a/gcc/cp/tinfo2.cc
+++ b/gcc/cp/tinfo2.cc
@@ -1,5 +1,5 @@
 // Methods for type_info for -*- C++ -*- Run Time Type Identification.
-// Copyright (C) 1994, 96-97, 1998, 1999 Free Software Foundation
+// Copyright (C) 1994, 96-97, 1998, 1999, 2000 Free Software Foundation
 
 // This file is part of GNU CC.
 
@@ -274,7 +274,7 @@ __dynamic_cast (const type_info& (*from)(void), const type_info& (*to)(void),
 {
   if (!require_public) abort();
   return static_cast <__user_type_info const &> (from ()).dyncast
-      (/*boff=*/-2, to (), address, sub (), subptr);
+      (/*boff=*/-1, to (), address, sub (), subptr);
 }
 
 extern "C" void *