From 846b9a06a618b615b065183950854d389c390177 Mon Sep 17 00:00:00 2001
From: Josh Matthews <josh@joshmatthews.net>
Date: Tue, 14 Feb 2012 16:26:05 -0500
Subject: [PATCH] Bug 704147 - Make ctypes function pointers callable via call
 and apply. r=bholley

---
 js/src/ctypes/CTypes.cpp                      | 20 ++++++++++------
 .../ctypes/tests/unit/test_jsctypes.js.in     | 23 +++++++++++++++++--
 2 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/js/src/ctypes/CTypes.cpp b/js/src/ctypes/CTypes.cpp
index b1f014c3470f..c638fd579b30 100644
--- a/js/src/ctypes/CTypes.cpp
+++ b/js/src/ctypes/CTypes.cpp
@@ -411,6 +411,12 @@ static JSPropertySpec sFunctionProps[] = {
   { 0, 0, 0, NULL, NULL }
 };
 
+static JSFunctionSpec sFunctionInstanceFunctions[] = {
+  JS_FN("call", js_fun_call, 1, CDATAFN_FLAGS),
+  JS_FN("apply", js_fun_apply, 2, CDATAFN_FLAGS),
+  JS_FS_END
+};
+
 static JSClass sInt64ProtoClass = {
   "Int64",
   0,
@@ -857,8 +863,8 @@ InitTypeClasses(JSContext* cx, JSObject* parent)
     return false;
   js::AutoObjectRooter sroot(cx, protos[SLOT_STRUCTDATAPROTO]);
 
-  if (!InitTypeConstructor(cx, parent, CTypeProto, CDataProto,
-         sFunctionFunction, NULL, sFunctionProps, NULL, NULL,
+  if (!InitTypeConstructor(cx, parent, CTypeProto, protos[SLOT_POINTERDATAPROTO],
+         sFunctionFunction, NULL, sFunctionProps, sFunctionInstanceFunctions, NULL,
          protos[SLOT_FUNCTIONPROTO], protos[SLOT_FUNCTIONDATAPROTO]))
     return false;
   js::AutoObjectRooter froot(cx, protos[SLOT_FUNCTIONDATAPROTO]);
@@ -3319,11 +3325,11 @@ PointerType::CreateInternal(JSContext* cx, JSObject* baseType)
     return JSVAL_TO_OBJECT(slot);
 
   // Get ctypes.PointerType.prototype and the common prototype for CData objects
-  // of this type.
-  JSObject* typeProto;
-  JSObject* dataProto;
-  typeProto = CType::GetProtoFromType(baseType, SLOT_POINTERPROTO);
-  dataProto = CType::GetProtoFromType(baseType, SLOT_POINTERDATAPROTO);
+  // of this type, or ctypes.FunctionType.prototype for function pointers.
+  CTypeProtoSlot slotId = CType::GetTypeCode(cx, baseType) == TYPE_function ?
+    SLOT_FUNCTIONDATAPROTO : SLOT_POINTERDATAPROTO;
+  JSObject* dataProto = CType::GetProtoFromType(cx, baseType, slotId);
+  JSObject* typeProto = CType::GetProtoFromType(cx, baseType, SLOT_POINTERPROTO);
 
   // Create a new CType object with the common properties and slots.
   JSObject* typeObj = CType::Create(cx, typeProto, dataProto, TYPE_pointer,
diff --git a/toolkit/components/ctypes/tests/unit/test_jsctypes.js.in b/toolkit/components/ctypes/tests/unit/test_jsctypes.js.in
index 3a9ae7f8e657..01bb6a99aab9 100644
--- a/toolkit/components/ctypes/tests/unit/test_jsctypes.js.in
+++ b/toolkit/components/ctypes/tests/unit/test_jsctypes.js.in
@@ -1328,7 +1328,10 @@ function run_type_ctor_class_tests(c, t, t2, props, fns, instanceProps, instance
   // equal to 't2.prototype.__proto__' where 't2' is a different CType
   // constructed from 'c'.
   do_check_true(t.prototype.__proto__ === t2.prototype.__proto__);
-  do_check_true(t.prototype.__proto__.__proto__ === ctypes.CData.prototype);
+  if (t instanceof ctypes.FunctionType)
+    do_check_true(t.prototype.__proto__.__proto__ === ctypes.PointerType.prototype.prototype);
+  else
+    do_check_true(t.prototype.__proto__.__proto__ === ctypes.CData.prototype);
   do_check_true(t.prototype instanceof ctypes.CData);
   do_check_true(t.prototype.constructor === t);
 
@@ -1359,7 +1362,10 @@ function run_type_ctor_class_tests(c, t, t2, props, fns, instanceProps, instance
     do_check_throws(function() { t.prototype[p]; }, Error);
 
   // Make sure we can access 'prototype' on a CTypeProto.
-  do_check_true(Object.getPrototypeOf(c.prototype.prototype) === ctypes.CType.prototype.prototype);
+  if (t instanceof ctypes.FunctionType)
+    do_check_true(Object.getPrototypeOf(c.prototype.prototype) === ctypes.PointerType.prototype.prototype);
+  else
+    do_check_true(Object.getPrototypeOf(c.prototype.prototype) === ctypes.CType.prototype.prototype);
 
   // Test that an instance 'd' of 't' is a CData.
   if (t.__proto__ != ctypes.FunctionType.prototype) {
@@ -2289,6 +2295,19 @@ function run_function_tests(library)
   // Test that we can call ptr().
   do_check_eq(ptr("function pointers rule!"), 23);
 
+  // Test that we can call via call and apply
+  do_check_eq(ptr.call(null, "function pointers rule!"), 23);
+  do_check_eq(ptr.apply(null, ["function pointers rule!"]), 23);
+
+  // Test that we cannot call non-function pointers via call and apply
+  let p_t = ctypes.PointerType(ctypes.int32_t);
+  let p = p_t();
+  do_check_throws(function() { p.call(null, "woo"); }, Error);
+  do_check_throws(function() { p.apply(null, ["woo"]); }, Error);
+
+  // Test the function pointers still behave as regular pointers
+  do_check_false(ptr.isNull(), "PointerType methods should still be valid");
+  
   // Test that library.declare() returns data of type FunctionType.ptr, and that
   // it is immutable.
   do_check_true(test_ansi_len.constructor.targetType.__proto__ ===