Add GetAllocationSite which try to recover allocation site of a given…

… object.
nbp · Feb 11, 2013 · 861435e · 861435e
1 parent 641bc07
commit 861435e
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Showing 3 changed files with 92 additions and 0 deletions.
diff --git a/js/src/jsfriendapi.cpp b/js/src/jsfriendapi.cpp
@@ -16,10 +16,12 @@
 #include "jswrapper.h"
 #include "jsweakmap.h"
 #include "jswatchpoint.h"
+#include "jsinfer.h"
 
 #include "builtin/TestingFunctions.h"
 
 #include "jsobjinlines.h"
+#include "jsinferinlines.h"
 
 using namespace js;
 using namespace JS;
@@ -1373,4 +1375,62 @@ StopWatchingLeaks(JSContext *cx)
     ReleaseWatchedSet(rt->defaultFreeOp());
 }
 
+JS_FRIEND_API(JSBool)
+GetAllocationSite(JSContext *cx, JSHandleObject object, JSMutableHandleValue loc)
+{
+    using namespace js::types;
+    loc.setUndefined();
+
+    TypeObject *obj = object->getType(cx);
+    if (!obj)
+        return true;
+
+    AllocationSiteKey location;
+    AllocationSiteTable *allocSites = cx->compartment->types.allocationSiteTable;
+    if (!allocSites)
+        return true;
+
+    /* Match the TypeObject to find the allocation site of the object. */
+    for (AllocationSiteTable::Range r = allocSites->all(); !r.empty(); r.popFront()) {
+        if (r.front().value == obj) {
+            location.script = r.front().key.script;
+            location.offset = r.front().key.offset;
+            location.kind = r.front().key.kind;
+            break;
+        }
+    }
+
+    RootedValue objectCtor(cx, UndefinedValue());
+    RootedObject global(cx, JS_GetGlobalObject(cx));
+    if (!JS_GetProperty(cx, global, "Object", objectCtor.address()))
+        return false;
+    if (!objectCtor.isObject())
+        return false;
+
+    RootedObject locObj(cx, JS_New(cx, &objectCtor.toObject(), 0, NULL));
+    if (!locObj)
+        return false;
+
+    const char *filename = JS_GetScriptFilename(cx, location.script);
+    if (!filename)
+        return false;
+
+    RootedValue v(cx);
+    RootedString filenameStr(cx, JS_NewStringCopyZ(cx, filename));
+    if (!filenameStr)
+        return false;
+
+    v.setString(filenameStr);
+    if (!JS_SetProperty(cx, locObj, "filename", v.address()))
+        return false;
+
+    jsbytecode *pc = location.script->code + location.offset;
+    v.setInt32(JS_PCToLineNumber(cx, location.script, pc));
+    if (!JS_SetProperty(cx, locObj, "line", v.address()))
+        return false;
+
+    loc.setObject(*locObj);
+    return true;
+}
+
 } /* namespace js */
diff --git a/js/src/jsfriendapi.h b/js/src/jsfriendapi.h
@@ -1448,6 +1448,10 @@ LiveWatchedObjects(JSContext *cx, JSMutableHandleValue watched);
 extern JS_FRIEND_API(void)
 StopWatchingLeaks(JSContext *cx);
 
+/* Attempt to recover the location where the object has been allocated. */
+extern JS_FRIEND_API(JSBool)
+GetAllocationSite(JSContext *cx, JSHandleObject object, JSMutableHandleValue loc);
+
 } /* namespace js */
 
 #endif /* jsfriendapi_h___ */
diff --git a/js/src/shell/js.cpp b/js/src/shell/js.cpp
@@ -2281,6 +2281,30 @@ DumpObject(JSContext *cx, unsigned argc, jsval *vp)
 
 #endif /* DEBUG */
 
+static JSBool
+GetAllocationSite(JSContext *cx, unsigned argc, jsval *vp)
+{
+    if (argc < 1) {
+        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_MORE_ARGS_NEEDED,
+                             "watchForLeak", "0", "s");
+        return false;
+    }
+
+    RootedValue target(cx, JS_ARGV(cx, vp)[0]);
+    if (!target.isObject()) {
+        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_UNEXPECTED_TYPE,
+                             "argument", "not an object");
+        return false;
+    }
+
+    RootedObject obj(cx, &target.toObject());
+    RootedValue allocSite(cx, UndefinedValue());
+    if (!js::GetAllocationSite(cx, obj, &allocSite))
+        return false;
+    JS_SET_RVAL(cx, vp, allocSite);
+    return true;
+}
+
 static JSBool
 BuildDate(JSContext *cx, unsigned argc, jsval *vp)
 {
@@ -3771,6 +3795,10 @@ static JSFunctionSpecWithHelp shell_functions[] = {
 "stopWatchingLeaks()",
 "  Clear meta-data needed for tracking logical leaks."),
 
+    JS_FN_HELP("getAllocationSite", GetAllocationSite, 0, 0,
+"getAllocationSite(object)",
+"  Attempt to recover the location of the allocation of the given object."),
+
     JS_FN_HELP("build", BuildDate, 0, 0,
 "build()",
 "  Show build date and time."),