Fix issue 259.

http://code.google.com/p/v8/issues/detail?id=259

Due to constant folding of loop conditions, it is possible to have a
try/finally with no exits from the try block (eg, an infinite loop in
the try block).  In that case the code to unlink the try handler is
dead and should not be emitted.

Review URL: http://codereview.chromium.org/39251

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1434 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/codegen-ia32.cc b/src/codegen-ia32.cc
index b5ac200..649c9e5 100644 (file)
--- a/src/codegen-ia32.cc
+++ b/src/codegen-ia32.cc
@@ -2830,22 +2830,29 @@ void CodeGenerator::VisitTryFinally(TryFinally* node) {
   }
 
   // Unlink from try chain; be careful not to destroy the TOS.
-  unlink.Bind();
-  // Reload sp from the top handler, because some statements that we
-  // break from (eg, for...in) may have left stuff on the stack.
-  // Preserve the TOS in a register across stack manipulation.
-  frame_->EmitPop(eax);
-  ExternalReference handler_address(Top::k_handler_address);
-  __ mov(edx, Operand::StaticVariable(handler_address));
-  const int kNextOffset = StackHandlerConstants::kNextOffset +
-      StackHandlerConstants::kAddressDisplacement;
-  __ lea(esp, Operand(edx, kNextOffset));
-  frame_->Forget(frame_->height() - handler_height);
-
-  frame_->EmitPop(Operand::StaticVariable(handler_address));
-  frame_->Drop(StackHandlerConstants::kSize / kPointerSize - 1);
-  // Next_sp popped.
-  frame_->EmitPush(eax);
+  if (unlink.is_linked()) {
+    unlink.Bind();
+  }
+
+  // Control can reach here via a jump to unlink or by falling off the
+  // end of the try block (with no unlinks).
+  if (has_valid_frame()) {
+    // Reload sp from the top handler, because some statements that we
+    // break from (eg, for...in) may have left stuff on the stack.
+    // Preserve the TOS in a register across stack manipulation.
+    frame_->EmitPop(eax);
+    ExternalReference handler_address(Top::k_handler_address);
+    __ mov(edx, Operand::StaticVariable(handler_address));
+    const int kNextOffset = StackHandlerConstants::kNextOffset +
+        StackHandlerConstants::kAddressDisplacement;
+    __ lea(esp, Operand(edx, kNextOffset));
+    frame_->Forget(frame_->height() - handler_height);
+
+    frame_->EmitPop(Operand::StaticVariable(handler_address));
+    frame_->Drop(StackHandlerConstants::kSize / kPointerSize - 1);
+    // Next_sp popped.
+    frame_->EmitPush(eax);
+  }
 
   // --- Finally block ---
   finally_block.Bind();

diff --git a/test/mjsunit/regress/regress-259.js b/test/mjsunit/regress/regress-259.js
new file mode 100644 (file)
index 0000000..f0476ff
--- /dev/null
+++ b/test/mjsunit/regress/regress-259.js
@@ -0,0 +1,33 @@
+// Copyright 2009 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Test that we do not crash when compiling a try/finally with an
+// infinite loop (with no normal exits) in the try block.
+
+// See http://code.google.com/p/v8/issues/detail?id=259
+
+assertThrows("try { while (true) { throw 0; }} finally {}");