Footprint wins: disable export/import from js1.5, fuse common code before a given jump target in js_Invoke, avoid unnecessary subtraction when enforcing ARGC_LIMIT. Also, clean up comment nits.

js/src/jsconfig.h

@@ -454,7 +454,7 @@
 #define JS_HAS_SEQUENCE_OPS     1       /* has array.slice, string.concat */
 #define JS_HAS_INITIALIZERS     1       /* has var o = {'foo': 42, 'bar':3} */
 #define JS_HAS_OBJ_WATCHPOINT   1       /* has o.watch and o.unwatch */
-#define JS_HAS_EXPORT_IMPORT    1       /* has export fun; import obj.fun */
+#define JS_HAS_EXPORT_IMPORT    0       /* has export fun; import obj.fun */
 #define JS_HAS_EVAL_THIS_SCOPE  1       /* Math.eval is same as with (Math) */
 #define JS_HAS_TRIPLE_EQOPS     1       /* has === and !== identity eqops */
 #define JS_HAS_SHARP_VARS       1       /* has #n=, #n# for object literals */

js/src/jsinterp.c

@@ -794,12 +794,10 @@ js_Invoke(JSContext *cx, uintN argc, uintN flags)
                 goto out2;
 
             if (JSVAL_IS_FUNCTION(cx, v)) {
-                funobj = JSVAL_TO_OBJECT(v);
-                parent = OBJ_GET_PARENT(cx, funobj);
-                fun = (JSFunction *) JS_GetPrivate(cx, funobj);
-
                 /* Make vp refer to funobj to keep it available as argv[-2]. */
                 *vp = v;
+                funobj = JSVAL_TO_OBJECT(v);
+                parent = OBJ_GET_PARENT(cx, funobj);
                 goto have_fun;
             }
         }
@@ -807,14 +805,14 @@ js_Invoke(JSContext *cx, uintN argc, uintN flags)
         script = NULL;
         minargs = nvars = 0;
 
-        /* Try a call or construct native object op, using fun as fallback. */
+        /* Try a call or construct native object op. */
         native = (flags & JSINVOKE_CONSTRUCT) ? ops->construct : ops->call;
         if (!native)
             goto bad;
     } else {
+have_fun:
         /* Get private data and set derived locals from it. */
         fun = (JSFunction *) JS_GetPrivate(cx, funobj);
-have_fun:
         native = fun->native;
         script = fun->script;
         minargs = fun->nargs + fun->extra;
@@ -825,7 +823,7 @@ have_fun:
             thisp = parent;
     }
 
-    /* Initialize frame except for varobj, thisp, sp, spbase, and scopeChain. */
+    /* Initialize the rest of frame, except for sp (set by SAVE_SP later). */
     frame.varobj = NULL;
     frame.callobj = frame.argsobj = NULL;
     frame.script = script;
@@ -1248,9 +1246,9 @@ ImportProperty(JSContext *cx, JSObject *obj, jsid id)
 
         /*
          * Handle the case of importing a property that refers to a local
-         * variable or formal parameter of a function activation.  Those
+         * variable or formal parameter of a function activation.  These
          * properties are accessed by opcodes using stack slot numbers
-         * generated by the compiler rather than runtime name-lookup. These
+         * generated by the compiler rather than runtime name-lookup.  These
          * local references, therefore, bypass the normal scope chain lookup.
          * So, instead of defining a new property in the activation object,
          * modify the existing value in the stack slot.
@@ -2979,7 +2977,7 @@ js_Interpret(JSContext *cx, jsval *result)
                  * NB: rval2 must be the property identifier, and rval the
                  * object from which to get the property.  The pair form an
                  * ECMA "reference type", which can be used on the right- or
-                 * left-hand side of assignment op.  Only native methods can
+                 * left-hand side of assignment ops.  Only native methods can
                  * return reference types.  See JSOP_SETCALL just below for
                  * the left-hand-side case.
                  */

js/src/jsparse.c

@@ -2698,7 +2698,7 @@ MemberExpr(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc,
 
         if (js_MatchToken(cx, ts, TOK_LP) && !ArgumentList(cx, ts, tc, pn))
             return NULL;
-        if (pn->pn_count - 1 >= ARGC_LIMIT) {
+        if (pn->pn_count > ARGC_LIMIT) {
             JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                                  JSMSG_TOO_MANY_CON_ARGS);
             return NULL;
@@ -2763,7 +2763,7 @@ MemberExpr(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc,
 
             if (!ArgumentList(cx, ts, tc, pn2))
                 return NULL;
-            if (pn2->pn_count - 1 >= ARGC_LIMIT) {
+            if (pn2->pn_count > ARGC_LIMIT) {
                 JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                                      JSMSG_TOO_MANY_FUN_ARGS);
                 return NULL;