Bug 665404 - Create JaegerCompartments lazily. r=luke.

js/src/jscntxtinlines.h

@@ -391,7 +391,7 @@ LeaveTraceIfArgumentsObject(JSContext *cx, JSObject *obj)
 #ifdef JS_METHODJIT
 inline js::mjit::JaegerCompartment *JSContext::jaegerCompartment()
 {
-    return compartment->jaegerCompartment;
+    return compartment->jaegerCompartment();
 }
 #endif
 

js/src/jscompartment.cpp

@@ -77,7 +77,7 @@ JSCompartment::JSCompartment(JSRuntime *rt)
     data(NULL),
     active(false),
 #ifdef JS_METHODJIT
-    jaegerCompartment(NULL),
+    jaegerCompartment_(NULL),
 #endif
 #if ENABLE_YARR_JIT
     regExpAllocator(NULL),
@@ -106,7 +106,7 @@ JSCompartment::~JSCompartment()
 #endif
 
 #ifdef JS_METHODJIT
-    Foreground::delete_(jaegerCompartment);
+    Foreground::delete_(jaegerCompartment_);
 #endif
 
 #ifdef JS_TRACER
@@ -145,20 +145,31 @@ JSCompartment::init()
     if (!backEdgeTable.init())
         return false;
 
-#ifdef JS_METHODJIT
-    jaegerCompartment = rt->new_<mjit::JaegerCompartment>();
-    if (!jaegerCompartment || !jaegerCompartment->Initialize())
-        return false;
-#endif
-        
     return true;
 }
 
 #ifdef JS_METHODJIT
+bool
+JSCompartment::ensureJaegerCompartmentExists(JSContext *cx)
+{
+    if (jaegerCompartment_)
+        return true;
+
+    mjit::JaegerCompartment *jc = cx->new_<mjit::JaegerCompartment>();
+    if (!jc)
+        return false;
+    if (!jc->Initialize()) {
+        cx->delete_(jc);
+        return false;
+    }
+    jaegerCompartment_ = jc;
+    return true;
+}
+
 size_t
 JSCompartment::getMjitCodeSize() const
 {
-    return jaegerCompartment->execAlloc()->getCodeSize();
+    return jaegerCompartment_ ? jaegerCompartment_->execAlloc()->getCodeSize() : 0;
 }
 #endif
 

js/src/jscompartment.h

@@ -412,13 +412,27 @@ struct JS_FRIEND_API(JSCompartment) {
     js::WrapperMap               crossCompartmentWrappers;
 
 #ifdef JS_METHODJIT
-    js::mjit::JaegerCompartment  *jaegerCompartment;
+  private:
+    /* This is created lazily because many compartments don't need it. */
+    js::mjit::JaegerCompartment  *jaegerCompartment_;
     /*
      * This function is here so that xpconnect/src/xpcjsruntime.cpp doesn't
      * need to see the declaration of JaegerCompartment, which would require
      * #including MethodJIT.h into xpconnect/src/xpcjsruntime.cpp, which is
      * difficult due to reasons explained in bug 483677.
      */
+  public:
+    bool hasJaegerCompartment() {
+        return !!jaegerCompartment_;
+    }
+
+    js::mjit::JaegerCompartment *jaegerCompartment() const {
+        JS_ASSERT(jaegerCompartment_);
+        return jaegerCompartment_;
+    }
+
+    bool ensureJaegerCompartmentExists(JSContext *cx);
+
     size_t getMjitCodeSize() const;
 #endif
     WTF::BumpPointerAllocator    *regExpAllocator;

js/src/jsregexpinlines.h

@@ -481,7 +481,10 @@ RegExp::compileHelper(JSContext *cx, JSLinearString &pattern)
 
 #if ENABLE_YARR_JIT && defined(JS_METHODJIT)
     if (EnableYarrJIT(cx) && !yarrPattern.m_containsBackreferences) {
-        JSC::Yarr::JSGlobalData globalData(cx->compartment->jaegerCompartment->execAlloc());
+        bool ok = cx->compartment->ensureJaegerCompartmentExists(cx);
+        if (!ok)
+            return false;
+        JSC::Yarr::JSGlobalData globalData(cx->compartment->jaegerCompartment()->execAlloc());
         JSC::Yarr::jitCompile(yarrPattern, &globalData, codeBlock);
         if (!codeBlock.isFallBack())
             return true;

js/src/methodjit/BaseCompiler.h

@@ -147,7 +147,7 @@ class LinkerHelper : public JSC::LinkBuffer
         // The pool is incref'd after this call, so it's necessary to release()
         // on any failure.
         JSScript *script = cx->fp()->script();
-        JSC::ExecutableAllocator *allocator = script->compartment->jaegerCompartment->execAlloc();
+        JSC::ExecutableAllocator *allocator = script->compartment->jaegerCompartment()->execAlloc();
         JSC::ExecutablePool *pool;
         m_code = executableAllocAndCopy(masm, allocator, &pool);
         if (!m_code) {

js/src/methodjit/Compiler.cpp

@@ -247,6 +247,9 @@ mjit::TryCompile(JSContext *cx, StackFrame *fp)
     if (fp->script()->hasSharps)
         return Compile_Abort;
 #endif
+    bool ok = cx->compartment->ensureJaegerCompartmentExists(cx);
+    if (!ok)
+        return Compile_Abort;
 
     // Ensure that constructors have at least one slot.
     if (fp->isConstructing() && !fp->script()->nslots)
@@ -411,7 +414,7 @@ mjit::Compiler::finishThisUp(JITScript **jitp)
 
     JSC::ExecutablePool *execPool;
     uint8 *result =
-        (uint8 *)script->compartment->jaegerCompartment->execAlloc()->alloc(codeSize, &execPool);
+        (uint8 *)script->compartment->jaegerCompartment()->execAlloc()->alloc(codeSize, &execPool);
     if (!result) {
         js_ReportOutOfMemory(cx);
         return Compile_Error;

js/src/methodjit/MethodJIT.cpp

@@ -118,14 +118,14 @@ extern "C" void JaegerTrampolineReturn();
 extern "C" void JS_FASTCALL
 PushActiveVMFrame(VMFrame &f)
 {
-    f.entryfp->script()->compartment->jaegerCompartment->pushActiveFrame(&f);
+    f.entryfp->script()->compartment->jaegerCompartment()->pushActiveFrame(&f);
     f.regs.fp()->setNativeReturnAddress(JS_FUNC_TO_DATA_PTR(void*, JaegerTrampolineReturn));
 }
 
 extern "C" void JS_FASTCALL
 PopActiveVMFrame(VMFrame &f)
 {
-    f.entryfp->script()->compartment->jaegerCompartment->popActiveFrame();
+    f.entryfp->script()->compartment->jaegerCompartment()->popActiveFrame();
 }
 
 extern "C" void JS_FASTCALL

js/src/methodjit/Retcon.cpp

@@ -128,7 +128,7 @@ Recompiler::recompile()
 
     // Find all JIT'd stack frames to account for return addresses that will
     // need to be patched after recompilation.
-    for (VMFrame *f = script->compartment->jaegerCompartment->activeFrame();
+    for (VMFrame *f = script->compartment->jaegerCompartment()->activeFrame();
          f != NULL;
          f = f->previous) {