Changeset 235419 in webkit for trunk/Source/JavaScriptCore/jit/JITExceptions.cpp

Timestamp:

Aug 27, 2018, 10:01:05 PM (7 years ago)

Author:

[email protected]

Message:

Fix exception throwing code so that topCallFrame and topEntryFrame stay true to their names.
​https://bugs.webkit.org/show_bug.cgi?id=188577
<rdar://problem/42985684>

Reviewed by Saam Barati.

JSTests:

• stress/regress-188577.js: Added.

Source/JavaScriptCore:

1. Introduced CallFrame::convertToStackOverflowFrame() which converts the current (top) CallFrame (which may not have a valid callee) into a StackOverflowFrame.

The StackOverflowFrame is a sentinel frame that the low level code (exception
throwing code, stack visitor, and stack unwinding code) will know to skip
over. The StackOverflowFrame will also have a valid JSCallee so that client
code can compute the globalObject or VM from this frame.

As a result, client code that throws StackOverflowErrors no longer need to
compute the caller frame to throw from: it just converts the top frame into
a StackOverflowFrame and everything should *Just Work*.

2. NativeCallFrameTracerWithRestore is now obsolete.

Instead, client code should always call convertToStackOverflowFrame() on the
frame before instantiating a NativeCallFrameTracer with it.

This means that topCallFrame will always point to the top CallFrame (which
may be a StackOverflowFrame), and topEntryFrame will always point to the top
EntryFrame. We'll never temporarily point them to the previous EntryFrame
(which we used to do with NativeCallFrameTracerWithRestore).

3. genericUnwind() and Interpreter::unwind() will now always unwind from the top CallFrame, and will know how to handle a StackOverflowFrame if they see one.

This obsoletes the UnwindStart flag.

• CMakeLists.txt:
• JavaScriptCore.xcodeproj/project.pbxproj:
• Sources.txt:
• debugger/Debugger.cpp:

(JSC::Debugger::pauseIfNeeded):

• interpreter/CallFrame.cpp:

(JSC::CallFrame::callerFrame const):
(JSC::CallFrame::unsafeCallerFrame const):
(JSC::CallFrame::convertToStackOverflowFrame):
(JSC::CallFrame::callerFrame): Deleted.
(JSC::CallFrame::unsafeCallerFrame): Deleted.

• interpreter/CallFrame.h:

(JSC::ExecState::iterate):

• interpreter/CallFrameInlines.h: Added.

(JSC::CallFrame::isStackOverflowFrame const):
(JSC::CallFrame::isWasmFrame const):

• interpreter/EntryFrame.h: Added.

(JSC::EntryFrame::vmEntryRecordOffset):
(JSC::EntryFrame::calleeSaveRegistersBufferOffset):

• interpreter/FrameTracers.h:

(JSC::NativeCallFrameTracerWithRestore::NativeCallFrameTracerWithRestore): Deleted.
(JSC::NativeCallFrameTracerWithRestore::~NativeCallFrameTracerWithRestore): Deleted.

• interpreter/Interpreter.cpp:

(JSC::Interpreter::unwind):

• interpreter/Interpreter.h:
• interpreter/StackVisitor.cpp:

(JSC::StackVisitor::StackVisitor):

• interpreter/StackVisitor.h:

(JSC::StackVisitor::visit):
(JSC::StackVisitor::topEntryFrameIsEmpty const):

• interpreter/VMEntryRecord.h:

(JSC::VMEntryRecord::callee const):
(JSC::EntryFrame::vmEntryRecordOffset): Deleted.
(JSC::EntryFrame::calleeSaveRegistersBufferOffset): Deleted.

• jit/AssemblyHelpers.h:
• jit/JITExceptions.cpp:

(JSC::genericUnwind):

• jit/JITExceptions.h:
• jit/JITOperations.cpp:
• llint/LLIntOffsetsExtractor.cpp:
• llint/LLIntSlowPaths.cpp:

(JSC::LLInt::LLINT_SLOW_PATH_DECL):

• llint/LowLevelInterpreter.asm:
• llint/LowLevelInterpreter32_64.asm:
• llint/LowLevelInterpreter64.asm:
• runtime/CallData.cpp:
• runtime/CommonSlowPaths.cpp:

(JSC::throwArityCheckStackOverflowError):
(JSC::SLOW_PATH_DECL):

• runtime/CommonSlowPathsExceptions.cpp: Removed.
• runtime/CommonSlowPathsExceptions.h: Removed.
• runtime/Completion.cpp:

(JSC::evaluateWithScopeExtension):

• runtime/JSGeneratorFunction.h:
• runtime/JSGlobalObject.cpp:

(JSC::JSGlobalObject::init):
(JSC::JSGlobalObject::visitChildren):

• runtime/JSGlobalObject.h:

(JSC::JSGlobalObject::stackOverflowFrameCallee const):

• runtime/VM.cpp:

(JSC::VM::throwException):

• runtime/VM.h:
• runtime/VMInlines.h:

(JSC::VM::topJSCallFrame const):

LayoutTests:

• http/tests/misc/large-js-program-expected.txt:

File:

• trunk/Source/JavaScriptCore/jit/JITExceptions.cpp (modified) (4 diffs)

trunk/Source/JavaScriptCore/jit/JITExceptions.cpp

@@ -31 +31 @@
 #include "CodeBlock.h"
 #include "Disassembler.h"
+#include "EntryFrame.h"
 #include "Interpreter.h"
 #include "JSCInlines.h"
@@ -39 +40 @@
 #include "Opcode.h"
 #include "ShadowChicken.h"
-#include "VM.h"
+#include "VMInlines.h"
 
 namespace JSC {
 
-void genericUnwind(VM* vm, ExecState* callFrame, UnwindStart unwindStart)
+void genericUnwind(VM* vm, ExecState* callFrame)
 {
     auto scope = DECLARE_CATCH_SCOPE(*vm);
+    CallFrame* topJSCallFrame = vm->topJSCallFrame();
     if (Options::breakOnThrow()) {
-        CodeBlock* codeBlock = callFrame->codeBlock();
-        if (codeBlock)
-            dataLog("In call frame ", RawPointer(callFrame), " for code block ", *codeBlock, "\n");
-        else
-            dataLog("In call frame ", RawPointer(callFrame), " with null CodeBlock\n");
+        CodeBlock* codeBlock = topJSCallFrame->codeBlock();
+        dataLog("In call frame ", RawPointer(topJSCallFrame), " for code block ", codeBlock, "\n");
         CRASH();
     }
     
-    ExecState* shadowChickenTopFrame = callFrame;
-    if (unwindStart == UnwindFromCallerFrame) {
-        EntryFrame* topEntryFrame = vm->topEntryFrame;
-        shadowChickenTopFrame = callFrame->callerFrame(topEntryFrame);
-    }
-    vm->shadowChicken().log(*vm, shadowChickenTopFrame, ShadowChicken::Packet::throwPacket());
-    
+    vm->shadowChicken().log(*vm, topJSCallFrame, ShadowChicken::Packet::throwPacket());
+
     Exception* exception = scope.exception();
     RELEASE_ASSERT(exception);
-    HandlerInfo* handler = vm->interpreter->unwind(*vm, callFrame, exception, unwindStart); // This may update callFrame.
+    HandlerInfo* handler = vm->interpreter->unwind(*vm, callFrame, exception); // This may update callFrame.
 
     void* catchRoutine;
@@ -84 +78 @@
     } else
         catchRoutine = LLInt::getCodePtr<ExceptionHandlerPtrTag>(handleUncaughtException).executableAddress();
-    
+
     ASSERT(bitwise_cast<uintptr_t>(callFrame) < bitwise_cast<uintptr_t>(vm->topEntryFrame));
 
@@ -95 +89 @@
 }
 
-void genericUnwind(VM* vm, ExecState* callFrame)
-{
-    genericUnwind(vm, callFrame, UnwindFromCurrentFrame);
-}
-
 } // namespace JSC