Merge pull request #217 from ThakeeNathees/super-calls

super class method call implemented

scripts/README.md

@@ -13,7 +13,7 @@ can download it your self at https://premake.github.io/download.
 python3 download_premake.py
 ```
 
-It will download and place the `premake.exe` (in windows) binary next to
+It will download and place the `premake5.exe` (in windows) binary next to
 it, next run the following command to generate Visual studio solution files.
 
 ```

scripts/premake5.lua

@@ -68,13 +68,3 @@ project "pocket_cli"
           cli_dir .. "**.h" }
   includedirs ({ src_dir .. "include/" })
   links { "pocket_static" }
-
-  
-  
-
-
-
-
-
-
-

src/pk_compiler.c

@@ -127,7 +127,7 @@ typedef enum {
   TK_TRUE,       // true
   TK_FALSE,      // false
   TK_SELF,       // self
-  // TODO: TK_SUPER
+  TK_SUPER,      // super
 
   TK_DO,         // do
   TK_THEN,       // then
@@ -191,6 +191,7 @@ static _Keyword _keywords[] = {
   { "true",     4, TK_TRUE     },
   { "false",    5, TK_FALSE    },
   { "self",     4, TK_SELF     },
+  { "super",    5, TK_SUPER    },
   { "do",       2, TK_DO       },
   { "then",     4, TK_THEN     },
   { "while",    5, TK_WHILE    },
@@ -1533,6 +1534,7 @@ static void exprSubscript(Compiler* compiler);
 static void exprValue(Compiler* compiler);
 
 static void exprSelf(Compiler* compiler);
+static void exprSuper(Compiler* compiler);
 
 #define NO_RULE { NULL,          NULL,          PREC_NONE }
 #define NO_INFIX PREC_NONE
@@ -1600,7 +1602,8 @@ GrammarRule rules[] = {  // Prefix       Infix             Infix Precedence
   /* TK_NOT        */ { exprUnaryOp,   NULL,             PREC_UNARY },
   /* TK_TRUE       */ { exprValue,     NULL,             NO_INFIX },
   /* TK_FALSE      */ { exprValue,     NULL,             NO_INFIX },
-  /* TK_FALSE      */ { exprSelf,      NULL,             NO_INFIX },
+  /* TK_SELF       */ { exprSelf,      NULL,             NO_INFIX },
+  /* TK_SUPER      */ { exprSuper,     NULL,             NO_INFIX },
   /* TK_DO         */   NO_RULE,
   /* TK_THEN       */   NO_RULE,
   /* TK_WHILE      */   NO_RULE,
@@ -2020,7 +2023,9 @@ static void exprMap(Compiler* compiler) {
 // is OP_METHOD_CALL the [method] should refer a string in the module's
 // constant pool, otherwise it's ignored.
 static void _compileCall(Compiler* compiler, Opcode call_type, int method) {
-  ASSERT((call_type == OP_CALL) || (call_type == OP_METHOD_CALL), OOPS);
+  ASSERT((call_type == OP_CALL) ||
+         (call_type == OP_METHOD_CALL) ||
+         (call_type == OP_SUPER_CALL), OOPS);
 
   // Compile parameters.
   int argc = 0;
@@ -2038,7 +2043,7 @@ static void _compileCall(Compiler* compiler, Opcode call_type, int method) {
 
   emitByte(compiler, argc);
 
-  if (call_type == OP_METHOD_CALL) {
+  if ((call_type == OP_METHOD_CALL) || (call_type == OP_SUPER_CALL)) {
     ASSERT_INDEX(method, (int)compiler->module->constants.count);
     emitShort(compiler, method);
   }
@@ -2146,6 +2151,42 @@ static void exprSelf(Compiler* compiler) {
   }
 }
 
+static void exprSuper(Compiler* compiler) {
+
+  if (compiler->func->type != FUNC_CONSTRUCTOR &&
+      compiler->func->type != FUNC_METHOD) {
+    semanticError(compiler, compiler->parser.previous,
+                  "Invalid use of 'super'.");
+    return;
+  }
+
+  ASSERT(compiler->func->ptr != NULL, OOPS);
+
+  int index = 0;
+  const char* name = compiler->func->ptr->name;
+  int name_length = -1;
+
+  if (!match(compiler, TK_LPARAN)) { // super.method().
+    consume(compiler, TK_DOT, "Invalid use of 'super'.");
+
+    consume(compiler, TK_NAME, "Expected a method name after 'super'.");
+    name = compiler->parser.previous.start;
+    name_length = compiler->parser.previous.length;
+
+    consume(compiler, TK_LPARAN, "Expected symbol '('.");
+
+  } else { // super().
+    name_length = (int)strlen(name);
+  }
+
+  if (compiler->parser.has_syntax_error) return;
+
+  emitOpcode(compiler, OP_PUSH_SELF);
+  moduleAddString(compiler->module, compiler->parser.vm,
+                  name, name_length, &index);
+  _compileCall(compiler, OP_SUPER_CALL, index);
+}
+
 static void parsePrecedence(Compiler* compiler, Precedence precedence) {
   lexToken(compiler);
   if (compiler->parser.has_syntax_error) return;

src/pk_core.c

@@ -968,21 +968,31 @@ Class* getClass(PKVM* vm, Var instance) {
   return inst->cls;
 }
 
-bool hasMethod(PKVM* vm, Var self, String* name, Closure** _method) {
-  Class* cls = getClass(vm, self);
-  ASSERT(cls != NULL, OOPS);
-
+// Returns a method on a class (it'll walk up the inheritance tree to search
+// and if the method not found, it'll return NULL.
+static inline Closure* clsGetMethod(Class* cls, String* name) {
   Class* cls_ = cls;
   do {
     for (int i = 0; i < (int)cls_->methods.count; i++) {
       Closure* method_ = cls_->methods.data[i];
       if (IS_CSTR_EQ(name, method_->fn->name, name->length)) {
-        if (_method) *_method = method_;
-        return true;
+        return method_;
       }
     }
     cls_ = cls_->super_class;
   } while (cls_ != NULL);
+  return NULL;
+}
+
+bool hasMethod(PKVM* vm, Var self, String* name, Closure** _method) {
+  Class* cls = getClass(vm, self);
+  ASSERT(cls != NULL, OOPS);
+
+  Closure* method_ = clsGetMethod(cls, name);
+  if (method_ != NULL) {
+    *_method = method_;
+    return true;
+  }
 
   return false;
 }
@@ -1000,6 +1010,22 @@ Var getMethod(PKVM* vm, Var self, String* name, bool* is_method) {
   return varGetAttrib(vm, self, name);
 }
 
+Closure* getSuperMethod(PKVM* vm, Var self, String* name) {
+  Class* super = getClass(vm, self)->super_class;
+  if (super == NULL) {
+    VM_SET_ERROR(vm, stringFormat(vm, "'$' object has no parent class.", \
+                 varTypeName(self)));
+    return NULL;
+  };
+
+  Closure* method = clsGetMethod(super, name);
+  if (method == NULL) {
+    VM_SET_ERROR(vm, stringFormat(vm, "'@' class has no method named '@'.", \
+                 super->name, name));
+  }
+  return method;
+}
+
 #define UNSUPPORTED_UNARY_OP(op)                                   \
   VM_SET_ERROR(vm, stringFormat(vm, "Unsupported operand ($) for " \
                "unary operator " op ".", varTypeName(v)))

src/pk_core.h

@@ -75,6 +75,10 @@ Class* getClass(PKVM* vm, Var instance);
 // If the method / attribute not found, it'll set a runtime error on the VM.
 Var getMethod(PKVM* vm, Var self, String* name, bool* is_method);
 
+// Returns the method (closure) from the instance's super class. If the method
+// doesn't exists, it'll set an error on the VM.
+Closure* getSuperMethod(PKVM* vm, Var self, String* name);
+
 // Unlike getMethod this will not set error and will not try to get attribute
 // with the same name. It'll return true if the method exists on [self], false
 // otherwise and if the [method] argument is not NULL, method will be set.

src/pk_debug.c

@@ -512,6 +512,7 @@ void dumpFunctionCode(PKVM* vm, Function* func) {
         break;
       }
 
+      case OP_SUPER_CALL:
       case OP_METHOD_CALL:
       {
         int argc = READ_BYTE();

src/pk_opcodes.h

@@ -133,7 +133,14 @@ OPCODE(POP, 0, -1)
 // params: 2 byte name index.
 OPCODE(IMPORT, 2, 1)
 
-// Call a method on the variable at the stack top. See opcode CALL for detail.
+// Call a super class's method on the variable at (stack_top - argc).
+// See opcode CALL for detail.
+// params: 2 bytes method name index in the constant pool.
+//         1 byte argc.
+OPCODE(SUPER_CALL, 3, -0) //< Stack size will be calculated at compile time.
+
+// Call a method on the variable at (stack_top - argc). See opcode CALL for
+// detail.
 // params: 2 bytes method name index in the constant pool.
 //         1 byte argc.
 OPCODE(METHOD_CALL, 3, -0) //< Stack size will be calculated at compile time.

src/pk_vm.c

@@ -889,13 +889,10 @@ L_vm_main_loop:
 
       if (strcmp(method->fn->name, CTOR_NAME) == 0) {
         cls->ctor = method;
-      } else {
-        // TODO: The method buffer should be ordered with it's name and
-        // inserted in a way to preserve the order to implement binary search
-        // to find a method.
-        pkClosureBufferWrite(&cls->methods, vm, method);
       }
 
+      pkClosureBufferWrite(&cls->methods, vm, method);
+
       DROP();
       DISPATCH();
     }
@@ -952,14 +949,28 @@ L_vm_main_loop:
       Var callable;
       const Closure* closure;
 
+      uint16_t index; //< To get the method name.
+      String* name; //< The method name.
+
+    OPCODE(SUPER_CALL):
+        argc = READ_BYTE();
+        fiber->ret = (fiber->sp - argc - 1);
+        fiber->self = *fiber->ret; //< Self for the next call.
+        index = READ_SHORT();
+        name = moduleGetStringAt(module, (int)index);
+        Closure* super_method = getSuperMethod(vm, fiber->self, name);
+        CHECK_ERROR(); // Will return if super_method is NULL.
+        callable = VAR_OBJ(super_method);
+      goto L_do_call;
+
     OPCODE(METHOD_CALL):
       argc = READ_BYTE();
       fiber->ret = (fiber->sp - argc - 1);
       fiber->self = *fiber->ret; //< Self for the next call.
 
-      uint16_t index = READ_SHORT();
+      index = READ_SHORT();
+      name = moduleGetStringAt(module, (int)index);
       bool is_method;
-      String* name = moduleGetStringAt(module, (int)index);
       callable = getMethod(vm, fiber->self, name, &is_method);
       CHECK_ERROR();
       goto L_do_call;
@@ -1055,16 +1066,18 @@ L_do_call:
 
       } else {
 
-        if (instruction == OP_CALL || instruction == OP_METHOD_CALL) {
+        if (instruction == OP_TAIL_CALL) {
+          reuseCallFrame(vm, closure);
+          LOAD_FRAME();  //< Re-load the frame to vm's execution variables.
+
+        } else {
+          ASSERT((instruction == OP_CALL) ||
+                 (instruction == OP_METHOD_CALL) ||
+                 (instruction == OP_SUPER_CALL), OOPS);
+
           UPDATE_FRAME(); //< Update the current frame's ip.
           pushCallFrame(vm, closure, fiber->ret);
           LOAD_FRAME();  //< Load the top frame to vm's execution variables.
-
-        } else {
-          ASSERT(instruction == OP_TAIL_CALL, OOPS);
-
-          reuseCallFrame(vm, closure);
-          LOAD_FRAME();  //< Re-load the frame to vm's execution variables.
         }
       }
 

tests/lang/class.pk

@@ -193,4 +193,44 @@ assert(!n5 == 3)
 assert(!n5 == 2)
 assert(!n5 == 1)
 
+###############################################################################
+## SUPER CLASS METHOD
+###############################################################################
+
+class A
+  def _init()
+    print("A init")
+  end
+  def foo()
+    print("A foo")
+    ret = self.bar()
+    assert(ret == "B.bar")
+    return "A.foo"
+  end
+  def bar()
+    print("A bar")
+    return "A.bar"
+  end
+end
+
+class B is A
+  def _init()
+    super()
+    print("B init")
+  end  
+  def foo()
+    print("B foo")
+    ret = super()
+    assert(ret == "A.foo")
+    return super.bar()
+  end
+  def bar()
+    print("B bar")
+    return "B.bar"
+  end
+end
+
+b = B()
+assert(b.foo() == "A.bar")
+
 print('ALL TESTS PASSED')