Bug 854564 - Fix SPS crash when running asm.js (r=sstangl)

--HG--
extra : rebase_source : 17be1e7c2425d9c821981bd3158f97da2d152f2a

js/src/ion/AsmJS.h

@@ -74,14 +74,13 @@ class AsmJSActivation
 {
     JSContext *cx_;
     const AsmJSModule &module_;
-    unsigned entryIndex_;
     AsmJSActivation *prev_;
     void *errorRejoinSP_;
     SPSProfiler *profiler_;
     void *resumePC_;
 
   public:
-    AsmJSActivation(JSContext *cx, const AsmJSModule &module, unsigned entryIndex);
+    AsmJSActivation(JSContext *cx, const AsmJSModule &module);
     ~AsmJSActivation();
 
     const AsmJSModule &module() const { return module_; }

js/src/ion/AsmJSLink.cpp

@@ -240,18 +240,16 @@ DynamicallyLinkModule(JSContext *cx, CallArgs args, AsmJSModule &module)
     return true;
 }
 
-AsmJSActivation::AsmJSActivation(JSContext *cx, const AsmJSModule &module, unsigned entryIndex)
+AsmJSActivation::AsmJSActivation(JSContext *cx, const AsmJSModule &module)
   : cx_(cx),
     module_(module),
-    entryIndex_(entryIndex),
     errorRejoinSP_(NULL),
     profiler_(NULL),
     resumePC_(NULL)
 {
     if (cx->runtime->spsProfiler.enabled()) {
         profiler_ = &cx->runtime->spsProfiler;
-        JSFunction *fun = module_.exportedFunction(entryIndex_).unclonedFunObj();
-        profiler_->enter(cx_, fun->nonLazyScript(), fun);
+        profiler_->enterNative("asm.js code", this);
     }
 
     prev_ = cx_->runtime->mainThread.asmJSActivationStack_;
@@ -264,10 +262,8 @@ AsmJSActivation::AsmJSActivation(JSContext *cx, const AsmJSModule &module, unsig
 
 AsmJSActivation::~AsmJSActivation()
 {
-    if (profiler_) {
-        JSFunction *fun = module_.exportedFunction(entryIndex_).unclonedFunObj();
-        profiler_->exit(cx_, fun->nonLazyScript(), fun);
-    }
+    if (profiler_)
+        profiler_->exitNative();
 
     JS_ASSERT(cx_->runtime->mainThread.asmJSActivationStack_ == this);
 
@@ -324,7 +320,7 @@ CallAsmJS(JSContext *cx, unsigned argc, Value *vp)
     }
 
     {
-        AsmJSActivation activation(cx, module, exportIndex);
+        AsmJSActivation activation(cx, module);
 
         // Call into generated code.
         if (!func.code()(coercedArgs.begin()))

js/src/vm/SPSProfiler.cpp

@@ -151,6 +151,24 @@ SPSProfiler::exit(JSContext *cx, RawScript script, RawFunction maybeFun)
 #endif
 }
 
+void
+SPSProfiler::enterNative(const char *string, void *sp)
+{
+    /* these operations cannot be re-ordered, so volatile-ize operations */
+    volatile ProfileEntry *stack = stack_;
+    volatile uint32_t *size = size_;
+    uint32_t current = *size;
+
+    JS_ASSERT(enabled());
+    if (current < max_) {
+        stack[current].setLabel(string);
+        stack[current].setStackAddress(sp);
+        stack[current].setScript(NULL);
+        stack[current].setLine(0);
+    }
+    *size = current + 1;
+}
+
 void
 SPSProfiler::push(const char *string, void *sp, RawScript script, jsbytecode *pc)
 {

js/src/vm/SPSProfiler.h

@@ -175,6 +175,10 @@ class SPSProfiler
         }
     }
 
+    /* Enter a C++ function. */
+    void enterNative(const char *string, void *sp);
+    void exitNative() { pop(); }
+
 #ifdef JS_METHODJIT
     struct ICInfo
     {