Patch: RFA: fix PR java/16789

[Tom Tromey]

This patch fixes PR 16789.

There are two parts to this bug.

First, we generated incorrect bytecode for something like
staticMethod().staticMethod() (which is valid but weird).  This was
compiled to <compound_expr <call> <call>>, and we weren't setting
CAN_COMPLETE_NORMALLY on the first call -- so jcf-write would omit the
second call.

Second, this construct was causing a crash in force_evaluation_order.
I believe the correct fix is to move the check for a no-argument call
below the code that unwraps the COMPOUND_EXPR.

Michael, I CC'd you since I think this might fix the ICE we were
debugging in irc yesterday.  It is worth a try anyway.

Tested on x86 FC2, including mauve and jacks.  Regression test
included.

Ok?

Tom

Index: gcc/java/ChangeLog
from  Tom Tromey  <tromey@redhat.com>
	PR java/16789:
	* parse.y (resolve_qualified_expression_name): Set
	CAN_COMPLETE_NORMALLY on first call when chaining static calls.
	* expr.c (force_evaluation_order): Check for empty argument list
	after stripping COMPOUND_EXPR.

Index: gcc/java/expr.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/java/expr.c,v
retrieving revision 1.204
diff -u -r1.204 expr.c
--- gcc/java/expr.c 25 Aug 2004 09:52:50 -0000 1.204
+++ gcc/java/expr.c 21 Sep 2004 22:24:41 -0000
@@ -3178,9 +3178,6 @@
     {
       tree arg, cmp;
 
-      if (!TREE_OPERAND (node, 1))
-	return node;
-
       arg = node;
       
       /* Position arg properly, account for wrapped around ctors. */
@@ -3189,7 +3186,11 @@
       
       arg = TREE_OPERAND (arg, 1);
       
-      /* Not having a list of argument here is an error. */ 
+      /* An empty argument list is ok, just ignore it.  */
+      if (!arg)
+	return node;
+
+      /* Not having a list of arguments here is an error. */ 
       if (TREE_CODE (arg) != TREE_LIST)
         abort ();
 
Index: gcc/java/parse.y
===================================================================
RCS file: /cvs/gcc/gcc/gcc/java/parse.y,v
retrieving revision 1.505
diff -u -r1.505 parse.y
--- gcc/java/parse.y 17 Sep 2004 21:55:01 -0000 1.505
+++ gcc/java/parse.y 21 Sep 2004 22:24:47 -0000
@@ -9607,6 +9607,9 @@
 	     forcoming function's argument. */
 	  if (previous_call_static && is_static)
 	    {
+	      /* We must set CAN_COMPLETE_NORMALLY for the first call
+		 since it is done nowhere else.  */
+	      CAN_COMPLETE_NORMALLY (decl) = 1;
 	      decl = build2 (COMPOUND_EXPR, TREE_TYPE (*where_found),
 			     decl, *where_found);
 	      TREE_SIDE_EFFECTS (decl) = 1;
Index: libjava/ChangeLog
from  Tom Tromey  <tromey@redhat.com>
	PR java/16789:
	* testsuite/libjava.lang/pr16789.out: New file.
	* testsuite/libjava.lang/pr16789.java: New file.

Index: libjava/testsuite/libjava.lang/pr16789.java
===================================================================
RCS file: libjava/testsuite/libjava.lang/pr16789.java
diff -N libjava/testsuite/libjava.lang/pr16789.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ libjava/testsuite/libjava.lang/pr16789.java 21 Sep 2004 22:24:50 -0000
@@ -0,0 +1,15 @@
+// gcj used to generate incorrect bytecode for
+// staticMethod().staticMethod()
+public class pr16789
+{
+  public void foo()
+  {
+    System.out.println(Thread.currentThread().holdsLock(this));
+  }
+
+  public static void main(String[] args)
+  {
+    new pr16789().foo();
+  }
+}
+
Index: libjava/testsuite/libjava.lang/pr16789.out
===================================================================
RCS file: libjava/testsuite/libjava.lang/pr16789.out
diff -N libjava/testsuite/libjava.lang/pr16789.out
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ libjava/testsuite/libjava.lang/pr16789.out 21 Sep 2004 22:24:50 -0000
@@ -0,0 +1 @@
+false