Improve Debugging for Undefined Structs

Author: fabcz

OCRunner/RunEnv/MFValue.mm

@@ -563,6 +563,24 @@ - (MFValue *)fieldForKey:(NSString *)key copied:(BOOL)copied{
     NSCAssert(self.type == OCTypeStruct, @"must be struct");
     NSString *structName = self.typeName;
     ORStructDeclare *declare = [[ORTypeSymbolTable shareInstance] symbolItemForTypeName:structName].declare;
+#if DEBUG
+    if (!declare) {
+        NSLog(@"\
+\n---------OCRunner Error---------\n\
+Unknown struct: '%@'\n\
+Tried to access the field '%@' of the struct '%@', but the struct '%@' was not defined in advance\n\
+You need to add the missing struct in OCRunner scripts.\n\
+For example:\n\
+If it is 'NSDirectionalEdgeInsets', then add the following struct:\n\
+```\n\
+typedef struct {\n\
+    CGFloat top, leading, bottom, trailing;\n\
+} NSDirectionalEdgeInsets;\n\
+```\n\
+-----------------------------------", structName, key, structName, structName);
+        NSAssert(false, @"As mentioned above");
+    }
+#endif
     NSUInteger offset = declare.keyOffsets[key].unsignedIntegerValue;
     MFValue *result = [MFValue defaultValueWithTypeEncoding:declare.keyTypeEncodes[key].UTF8String];
     if (copied) {

OCRunnerTests/ORTestWithObjc.m

@@ -373,6 +373,23 @@ - (void)testStructGetValue{
     XCTAssert(aValue.type == OCTypeDouble);
     XCTAssert(aValue.doubleValue == 4);
 }
+- (void)testStructGetValueNoDefine{
+    //    NSString *source = @"\
+    //    struct NSDirectionalEdgeInsets {\
+    //        CGFloat top, leading, bottom, trailing;\
+    //    };\
+    //    CGFloat top = UIApplication.sharedApplication.keyWindow.directionalLayoutMargins.top;\
+    //    ";
+    NSString *source = @"CGFloat top = UIApplication.sharedApplication.keyWindow.directionalLayoutMargins.top;";
+    MFScopeChain *scope = self.currentScope;
+    AST *ast = [_parser parseSource:source];
+    for (id <OCExecute> exp in ast.globalStatements) {
+        [exp execute:scope];
+    }
+    if (@available(iOS 11.0, *)) {
+        XCTAssert(UIApplication.sharedApplication.keyWindow.directionalLayoutMargins.top == [scope getValueWithIdentifier:@"top"].doubleValue);
+    }
+}
 - (void)testDetectStructMemeryLayoutCode{
     NSString *result = detectStructMemeryLayoutEncodeCode("{CGRect={CGPoint=ff{CGPoint=dd}}{CGSize=dd}}");
     XCTAssert([result isEqualToString:@"ffdddd"]);