[WebIDL] Generate correct code when a pointer is returned from an interface method

Author: agnickolov

AUTHORS

@@ -598,3 +598,4 @@ a license to everyone to use it as detailed in LICENSE.)
 * Jerry Zhuang <[email protected]>
 * Taisei Kon <[email protected]>
 * YAMAMOTO Takashi <[email protected]>
+* Artur Gatin <[email protected]> (copyright owned by Teladoc Health, Inc.)

test/webidl/post.js

@@ -243,6 +243,20 @@ try {
   s.Print(123, null); // Expects a string or a wrapped pointer
 } catch (e) {}
 
+// Returned pointers (issue 14745)
+
+var factory = new TheModule.ObjectFactory();
+var objectProvider = factory.getProvider();
+var smallObject = objectProvider.getObject();
+
+// This will print 123 if we managed to access the object, which means that integers
+// were correctly typecast to ObjectProvider pointer and SmallObject pointer.
+console.log(smallObject.getID(123));
+
+TheModule.destroy(factory)
+
+// end of issue 14745
+
 // Check for overflowing the stack
 
 var before = Date.now();
@@ -285,7 +299,5 @@ if (isMemoryGrowthAllowed) {
   }
 }
 
-//
-
 console.log('\ndone.')
 })();

test/webidl/test.h

@@ -194,3 +194,38 @@ typedef struct LongLongTypes {
   unsigned long long* lluArray;
   long long ll;
 } LongLongTypes;
+
+// Returning child objects in a hierarchy
+
+struct ISmallObject {
+  virtual int getID(int number) = 0;
+};
+
+struct IObjectProvider {
+  virtual ISmallObject* getObject() = 0;
+};
+
+class SmallObject : public ISmallObject {
+public:
+  int getID(int number) {
+    return number;
+  }
+};
+
+class ObjectProvider : public IObjectProvider {
+public:
+  ISmallObject* getObject() {
+    return &m_smallObject;
+  }
+private:
+  SmallObject m_smallObject;
+};
+
+class ObjectFactory {
+public:
+  IObjectProvider* getProvider() {
+    return &m_ObjectProvider;
+  }
+private:
+  ObjectProvider m_ObjectProvider;
+};

test/webidl/test.idl

@@ -169,3 +169,30 @@ interface LongLongTypes {
   readonly attribute unsigned long long[] lluArray;
   attribute long long ll;
 };
+
+[NoDelete]
+interface ISmallObject {
+  long getID(long number);
+};
+
+[JSImplementation="ISmallObject"]
+interface JSSmallObject {
+  void JSSmallObject();
+  long getID(long number);
+};
+
+[NoDelete]
+interface IObjectProvider {
+  ISmallObject getObject();
+};
+
+[JSImplementation="IObjectProvider"]
+interface JSObjectProvider {
+  void JSObjectProvider();
+  JSSmallObject getObject();
+};
+
+interface ObjectFactory {
+  void ObjectFactory();
+  IObjectProvider getProvider();
+};

test/webidl/test_ALL.out

@@ -109,3 +109,4 @@ Aborted(Assertion failed: [CHECK FAILED] Parent::Parent(val:val): Expecting <int
 Parent:42
 Aborted(Assertion failed: [CHECK FAILED] Parent::voidStar(something:something): Expecting <pointer>)
 Aborted(Assertion failed: [CHECK FAILED] StringUser::Print(anotherString:anotherString): Expecting <string>)
+123

test/webidl/test_DEFAULT.out

@@ -108,5 +108,6 @@ struct_ptr_array[0]->attr2 == 101
 Parent:0
 Parent:42
 |abc|1|(null)|123|
+123
 
 done.

test/webidl/test_FAST.out

@@ -108,5 +108,6 @@ struct_ptr_array[0]->attr2 == 101
 Parent:0
 Parent:42
 |abc|1|(null)|123|
+123
 
 done.

tools/webidl_binder.py

@@ -647,15 +647,16 @@ def make_call_args(i):
       if i == max_args:
         dec_args = ', '.join([type_to_cdec(raw[j]) + ' ' + args[j] for j in range(i)])
         js_call_args = ', '.join(['%s%s' % (('(ptrdiff_t)' if sig[j] in interfaces else '') + take_addr_if_nonpointer(raw[j]), args[j]) for j in range(i)])
+        em_asm_macro = 'EM_ASM_%s' % ('PTR' if c_return_type[-1] == '*' else 'INT' if c_return_type not in C_FLOATS else 'DOUBLE')
 
         js_impl_methods.append(r'''  %s %s(%s) %s {
-    %sEM_ASM_%s({
+    %s (%s) %s({
       var self = Module['getCache'](Module['%s'])[$0];
       if (!self.hasOwnProperty('%s')) throw 'a JSImplementation must implement all functions, you forgot %s::%s.';
       %sself['%s'](%s)%s;
     }, (ptrdiff_t)this%s);
   }''' % (c_return_type, func_name, dec_args, maybe_const,
-          basic_return, 'INT' if c_return_type not in C_FLOATS else 'DOUBLE',
+          basic_return, c_return_type, em_asm_macro,
           class_name,
           func_name, class_name, func_name,
           return_prefix,