Fix a bug in abrupt exit from with or catch inside finally.

When with or catch is nested inside finally, we were not properly restoring
the context in the stack for the finally code.  Also, as a small
optimization, restore it from the handler block instead of iteratively
unwinding contexts.

R=fschneider@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/7837023

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9160 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/full-codegen-arm.cc

@@ -4290,6 +4290,34 @@ void FullCodeGenerator::ExitFinallyBlock() {
 }
 
 
+#undef __
+
+#define __ ACCESS_MASM(masm())
+
+FullCodeGenerator::NestedStatement* FullCodeGenerator::TryFinally::Exit(
+    int* stack_depth,
+    int* context_length) {
+  // The macros used here must preserve the result register.
+
+  // Because the handler block contains the context of the finally
+  // code, we can restore it directly from there for the finally code
+  // rather than iteratively unwinding contexts via their previous
+  // links.
+  __ Drop(*stack_depth);  // Down to the handler block.
+  if (*context_length > 0) {
+    // Restore the context to its dedicated register and the stack.
+    __ ldr(cp, MemOperand(sp, StackHandlerConstants::kContextOffset));
+    __ str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  }
+  __ PopTryHandler();
+  __ bl(finally_entry_);
+
+  *stack_depth = 0;
+  *context_length = 0;
+  return previous_;
+}
+
+
 #undef __
 
 } }  // namespace v8::internal

src/full-codegen.cc

@@ -1354,25 +1354,6 @@ void FullCodeGenerator::VisitThrow(Throw* expr) {
 }
 
 
-FullCodeGenerator::NestedStatement* FullCodeGenerator::TryFinally::Exit(
-    int* stack_depth,
-    int* context_length) {
-  // The macros used here must preserve the result register.
-  __ Drop(*stack_depth);
-  __ PopTryHandler();
-  *stack_depth = 0;
-
-  Register context = FullCodeGenerator::context_register();
-  while (*context_length > 0) {
-    codegen_->LoadContextField(context, Context::PREVIOUS_INDEX);
-    --(*context_length);
-  }
-
-  __ Call(finally_entry_);
-  return previous_;
-}
-
-
 FullCodeGenerator::NestedStatement* FullCodeGenerator::TryCatch::Exit(
     int* stack_depth,
     int* context_length) {

src/ia32/full-codegen-ia32.cc

@@ -4346,6 +4346,34 @@ void FullCodeGenerator::ExitFinallyBlock() {
 }
 
 
+#undef __
+
+#define __ ACCESS_MASM(masm())
+
+FullCodeGenerator::NestedStatement* FullCodeGenerator::TryFinally::Exit(
+    int* stack_depth,
+    int* context_length) {
+  // The macros used here must preserve the result register.
+
+  // Because the handler block contains the context of the finally
+  // code, we can restore it directly from there for the finally code
+  // rather than iteratively unwinding contexts via their previous
+  // links.
+  __ Drop(*stack_depth);  // Down to the handler block.
+  if (*context_length > 0) {
+    // Restore the context to its dedicated register and the stack.
+    __ mov(esi, Operand(esp, StackHandlerConstants::kContextOffset));
+    __ mov(Operand(ebp, StandardFrameConstants::kContextOffset), esi);
+  }
+  __ PopTryHandler();
+  __ call(finally_entry_);
+
+  *stack_depth = 0;
+  *context_length = 0;
+  return previous_;
+}
+
+
 #undef __
 
 } }  // namespace v8::internal

src/mips/full-codegen-mips.cc

@@ -4291,6 +4291,34 @@ void FullCodeGenerator::ExitFinallyBlock() {
 }
 
 
+#undef __
+
+#define __ ACCESS_MASM(masm())
+
+FullCodeGenerator::NestedStatement* FullCodeGenerator::TryFinally::Exit(
+    int* stack_depth,
+    int* context_length) {
+  // The macros used here must preserve the result register.
+
+  // Because the handler block contains the context of the finally
+  // code, we can restore it directly from there for the finally code
+  // rather than iteratively unwinding contexts via their previous
+  // links.
+  __ Drop(*stack_depth);  // Down to the handler block.
+  if (*context_length > 0) {
+    // Restore the context to its dedicated register and the stack.
+    __ lw(cp, MemOperand(sp, StackHandlerConstants::kContextOffset));
+    __ sw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  }
+  __ PopTryHandler();
+  __ Call(finally_entry_);
+
+  *stack_depth = 0;
+  *context_length = 0;
+  return previous_;
+}
+
+
 #undef __
 
 } }  // namespace v8::internal

src/x64/full-codegen-x64.cc

@@ -4228,6 +4228,33 @@ void FullCodeGenerator::ExitFinallyBlock() {
 
 #undef __
 
+#define __ ACCESS_MASM(masm())
+
+FullCodeGenerator::NestedStatement* FullCodeGenerator::TryFinally::Exit(
+    int* stack_depth,
+    int* context_length) {
+  // The macros used here must preserve the result register.
+
+  // Because the handler block contains the context of the finally
+  // code, we can restore it directly from there for the finally code
+  // rather than iteratively unwinding contexts via their previous
+  // links.
+  __ Drop(*stack_depth);  // Down to the handler block.
+  if (*context_length > 0) {
+    // Restore the context to its dedicated register and the stack.
+    __ movq(rsi, Operand(rsp, StackHandlerConstants::kContextOffset));
+    __ movq(Operand(rbp, StandardFrameConstants::kContextOffset), rsi);
+  }
+  __ PopTryHandler();
+  __ call(finally_entry_);
+
+  *stack_depth = 0;
+  *context_length = 0;
+  return previous_;
+}
+
+
+#undef __
 
 } }  // namespace v8::internal
 

test/mjsunit/regress/regress-95485.js

@@ -0,0 +1,42 @@
+// Copyright 2011 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.
+
+function Test() {
+  var left  = 'XXX';
+  var right = 'YYY';
+  for (var i = 0; i < 3; i++) {
+    var cons = left + right;
+    var substring = cons.substring(2, 4);
+    try {
+      with ({Test: i})
+          continue;
+    } finally { }
+  }
+  return substring;
+}
+
+assertEquals('XY', Test());