Bug 879079 - Fix static root analysis hazards around ValueToSource; r=sfink

--HG--
extra : rebase_source : 2f31fdefdcdd6bb95beace105f6b79458d3a407f

js/src/jsopcode.cpp

@@ -1339,7 +1339,8 @@ ExpressionDecompiler::decompilePC(jsbytecode *pc)
         JSObject *obj = (op == JSOP_REGEXP)
                         ? script->getRegExp(GET_UINT32_INDEX(pc))
                         : script->getObject(GET_UINT32_INDEX(pc));
-        JSString *str = ValueToSource(cx, ObjectValue(*obj));
+        RootedValue objv(cx, ObjectValue(*obj));
+        JSString *str = ValueToSource(cx, objv);
         if (!str)
             return false;
         return write(str);
@@ -2120,7 +2121,7 @@ js::GetPCCountScriptSummary(JSContext *cx, size_t index)
 
     AppendJSONProperty(buf, "file", NO_COMMA);
     JSString *str = JS_NewStringCopyZ(cx, script->filename());
-    if (!str || !(str = ValueToSource(cx, StringValue(str))))
+    if (!str || !(str = StringToSource(cx, str)))
         return NULL;
     buf.append(str);
 
@@ -2131,7 +2132,7 @@ js::GetPCCountScriptSummary(JSContext *cx, size_t index)
         JSAtom *atom = script->function()->displayAtom();
         if (atom) {
             AppendJSONProperty(buf, "name");
-            if (!(str = ValueToSource(cx, StringValue(atom))))
+            if (!(str = StringToSource(cx, atom)))
                 return NULL;
             buf.append(str);
         }
@@ -2218,7 +2219,7 @@ GetPCCountJSON(JSContext *cx, const ScriptAndCounts &sac, StringBuffer &buf)
     AppendJSONProperty(buf, "text", NO_COMMA);
 
     JSString *str = JS_DecompileScript(cx, script, NULL, 0);
-    if (!str || !(str = ValueToSource(cx, StringValue(str))))
+    if (!str || !(str = StringToSource(cx, str)))
         return false;
 
     buf.append(str);
@@ -2274,7 +2275,7 @@ GetPCCountJSON(JSContext *cx, const ScriptAndCounts &sac, StringBuffer &buf)
             AppendJSONProperty(buf, "text");
             JSString *str = JS_NewStringCopyZ(cx, text);
             js_free(text);
-            if (!str || !(str = ValueToSource(cx, StringValue(str))))
+            if (!str || !(str = StringToSource(cx, str)))
                 return false;
             buf.append(str);
         }
@@ -2335,7 +2336,7 @@ GetPCCountJSON(JSContext *cx, const ScriptAndCounts &sac, StringBuffer &buf)
 
                 AppendJSONProperty(buf, "code");
                 JSString *str = JS_NewStringCopyZ(cx, block.code());
-                if (!str || !(str = ValueToSource(cx, StringValue(str))))
+                if (!str || !(str = StringToSource(cx, str)))
                     return false;
                 buf.append(str);
 

js/src/jsstr.cpp

@@ -343,7 +343,7 @@ static JSBool
 str_uneval(JSContext *cx, unsigned argc, Value *vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
-    JSString *str = ValueToSource(cx, args.get(0));
+    JSString *str = ValueToSource(cx, args.handleOrUndefinedAt(0));
     if (!str)
         return false;
 
@@ -3804,7 +3804,7 @@ template JSString *
 js::ToStringSlow<NoGC>(JSContext *cx, Value arg);
 
 JSString *
-js::ValueToSource(JSContext *cx, const Value &v)
+js::ValueToSource(JSContext *cx, HandleValue v)
 {
     JS_CHECK_RECURSION(cx, return NULL);
     assertSameCompartment(cx, v);
@@ -3812,7 +3812,7 @@ js::ValueToSource(JSContext *cx, const Value &v)
     if (v.isUndefined())
         return cx->names().void0;
     if (v.isString())
-        return js_QuoteString(cx, v.toString(), '"');
+        return StringToSource(cx, v.toString());
     if (v.isPrimitive()) {
         /* Special case to preserve negative zero, _contra_ toString. */
         if (v.isDouble() && IsNegativeZero(v.toDouble())) {
@@ -3821,8 +3821,7 @@ js::ValueToSource(JSContext *cx, const Value &v)
 
             return js_NewStringCopyN<CanGC>(cx, js_negzero_ucNstr, 2);
         }
-        RootedValue vRoot(cx, v);
-        return ToString<CanGC>(cx, vRoot);
+        return ToString<CanGC>(cx, v);
     }
 
     RootedValue rval(cx, NullValue());
@@ -3838,6 +3837,12 @@ js::ValueToSource(JSContext *cx, const Value &v)
     return ToString<CanGC>(cx, rval);
 }
 
+JSString *
+js::StringToSource(JSContext *cx, JSString *str)
+{
+    return js_QuoteString(cx, str, '"');
+}
+
 bool
 js::EqualStrings(JSContext *cx, JSString *str1, JSString *str2, bool *result)
 {

js/src/jsstr.h

@@ -165,7 +165,15 @@ namespace js {
  * an error, otherwise returning a new string reference.
  */
 extern JSString *
-ValueToSource(JSContext *cx, const js::Value &v);
+ValueToSource(JSContext *cx, HandleValue v);
+
+/*
+ * Convert a JSString to its source expression; returns null after reporting an
+ * error, otherwise returns a new string reference. No Handle needed since the
+ * input is dead after the GC.
+ */
+extern JSString *
+StringToSource(JSContext *cx, JSString *str);
 
 /*
  * Test if strings are equal. The caller can call the function even if str1