re PR java/20056 ('verification failed: incompatible type on stack' with --indirect-dispatch)

	PR java/20056:
	* verify.cc (type::EITHER): New constant.
	(check_field_constant): Use it.
	(type::compatible): Handle it.

From-SVN: r95403

2 files changed, 42 insertions, 14 deletions

diff --git a/libjava/ChangeLog b/libjava/ChangeLog
index b1fbc96..324a5b2 100644
--- a/libjava/ChangeLog
+++ b/libjava/ChangeLog
@@ -1,3 +1,10 @@
+2005-02-22  Tom Tromey  <tromey@redhat.com>
+
+	PR java/20056:
+	* verify.cc (type::EITHER): New constant.
+	(check_field_constant): Use it.
+	(type::compatible): Handle it.
+
 2005-02-22  Michael Koch  <konqueror@gmx.de>
 
 	* gnu/java/security/PolicyFile.java,
diff --git a/libjava/verify.cc b/libjava/verify.cc
index a809307..141f27a 100644
--- a/libjava/verify.cc
+++ b/libjava/verify.cc
@@ -578,9 +578,11 @@ private:
     //
     // First, when constructing a new object, it is the PC of the
     // `new' instruction which created the object.  We use the special
-    // value UNINIT to mean that this is uninitialized, and the
-    // special value SELF for the case where the current method is
-    // itself the <init> method.
+    // value UNINIT to mean that this is uninitialized.  The special
+    // value SELF is used for the case where the current method is
+    // itself the <init> method.  the special value EITHER is used
+    // when we may optionally allow either an uninitialized or
+    // initialized reference to match.
     //
     // Second, when the key is return_address_type, this holds the PC
     // of the instruction following the `jsr'.
@@ -588,6 +590,7 @@ private:
 
     static const int UNINIT = -2;
     static const int SELF = -1;
+    static const int EITHER = -3;
 
     // Basic constructor.
     type ()
@@ -734,19 +737,33 @@ private:
       if (k.klass == NULL)
 	verifier->verify_fail ("programmer error in type::compatible");
 
-      // An initialized type and an uninitialized type are not
-      // compatible.
-      if (isinitialized () != k.isinitialized ())
-	return false;
-
-      // Two uninitialized objects are compatible if either:
-      // * The PCs are identical, or
-      // * One PC is UNINIT.
-      if (! isinitialized ())
+      // Handle the special 'EITHER' case, which is only used in a
+      // special case of 'putfield'.  Note that we only need to handle
+      // this on the LHS of a check.
+      if (! isinitialized () && pc == EITHER)
 	{
-	  if (pc != k.pc && pc != UNINIT && k.pc != UNINIT)
+	  // If the RHS is uninitialized, it must be an uninitialized
+	  // 'this'.
+	  if (! k.isinitialized () && k.pc != SELF)
 	    return false;
 	}
+      else if (isinitialized () != k.isinitialized ())
+	{
+	  // An initialized type and an uninitialized type are not
+	  // otherwise compatible.
+	  return false;
+	}
+      else
+	{
+	  // Two uninitialized objects are compatible if either:
+	  // * The PCs are identical, or
+	  // * One PC is UNINIT.
+	  if (! isinitialized ())
+	    {
+	      if (pc != k.pc && pc != UNINIT && k.pc != UNINIT)
+		return false;
+	    }
+	}
 
       return klass->compatible(k.klass, verifier);
     }
@@ -2003,7 +2020,11 @@ private:
 	// We don't look at the signature, figuring that if it is
 	// wrong we will fail during linking.  FIXME?
 	&& _Jv_Linker::has_field_p (current_class, name))
-      class_type->set_uninitialized (type::SELF, this);
+      // Note that we don't actually know whether we're going to match
+      // against 'this' or some other object of the same type.  So,
+      // here we set things up so that it doesn't matter.  This relies
+      // on knowing what our caller is up to.
+      class_type->set_uninitialized (type::EITHER, this);
 
     return result;
   }