M projects/08/src/codewriter.h → projects/08/src/codewriter.h

@@ -97,12 +97,14 @@ "0;JMP\n"              // return
                        "\n"
                        "(__comp_funcs_end)\n";
 
-char vm_init[] = "//@256\n"  // starting address of stack (nothing pushed yet)
-                 "//D=A\n"   // D = 256
-                 "//@SP\n"   // A = <constant representing address of SP>
-                 "//M=D\n"   // <memory pointed to by SP> = 256
+char vm_init[] = "@256\n"  // starting address of stack (nothing pushed yet)
+                 "D=A\n"   // D = 256
+                 "@SP\n"   // A = <constant representing address of SP>
+                 "M=D\n"   // <memory pointed to by SP> = 256
                  "\n%s\n";   // <- comp_vm_funcs
 // TODO: add initializers for argument, local, static, constant, this, that
+
+// TODO only output vm_stop when Main.main
 char vm_stop[] = "(END)\n"   // starting address of stack (nothing pushed yet)
                  "@END\n"    // D = 256
                  "0;JMP\n";  // A = <constant representing address of SP>
@@ -332,20 +334,79 @@ 
 	return true;
 }
 
+static bool write_label(struct vm_instruction_t *vm_instr, FILE *fp)
+{
+	char label_asm[] = "(%s)\n";
+	fprintf(fp, label_asm, vm_instr->arg1);
+	return true;
+}
+
+static bool write_goto(struct vm_instruction_t *vm_instr, FILE *fp)
+{
+	char goto_asm[] = "@%s\n"
+	                  "0;JMP\n";
+	fprintf(fp, goto_asm, vm_instr->arg1);
+	return true;
+}
+
+static bool write_if(struct vm_instruction_t *vm_instr, FILE *fp)
+{
+	char if_asm[] = "@SP\n"  // pop register D
+	                "AM=M-1\n"
+	                "D=M\n"     // pop value into D register
+	                "@%s\n"
+	                "D;JNE\n";
+	fprintf(fp, if_asm, vm_instr->arg1);
+	return true;
+}
+
+static bool write_function(struct vm_instruction_t *vm_instr, FILE *fp)
+{
+	print_vm_instruction(vm_instr, fp);
+	return true;  // STUB TODO implement
+}
+
+static bool write_return(struct vm_instruction_t *vm_instr, FILE *fp)
+{
+	print_vm_instruction(vm_instr, fp);
+	return true;  // STUB TODO implement
+}
+
+static bool write_call(struct vm_instruction_t *vm_instr, FILE *fp)
+{
+	print_vm_instruction(vm_instr, fp);
+	return true;  // STUB TODO implement
+}
+
 bool write_instruction(struct vm_instruction_t *vm_instr, FILE *fp)
 {
 	fprintf(fp, "\n// %lu: %s\n", file_line_no, vm_instr->line);
-	if (vm_instr->cmd == C_ARITHMETIC) {
-		write_arithmetic(vm_instr, fp);
-	} else if (vm_instr->cmd == C_PUSH) {
-		write_push(vm_instr, fp);
-	} else if (vm_instr->cmd == C_POP) {
-		write_pop(vm_instr, fp);
-	} else {
+
+	switch (vm_instr->cmd) {
+	case C_ARITHMETIC:
+		return write_arithmetic(vm_instr, fp);
+	case C_PUSH:
+		return write_push(vm_instr, fp);
+	case C_POP:
+		return write_pop(vm_instr, fp);
+	case C_LABEL:
+		return write_label(vm_instr, fp);
+	case C_GOTO:
+		return write_goto(vm_instr, fp);
+	case C_IF:
+		return write_if(vm_instr, fp);
+	case C_FUNCTION:
+		return write_function(vm_instr, fp);
+	case C_RETURN:
+		return write_return(vm_instr, fp);
+	case C_CALL:
+		return write_call(vm_instr, fp);
+	default:
 		err("error: unrecognized instruction (%u)\n", vm_instr->cmd);
 		return false;
 	}
-	return true;
+
+	return false;  // should never reach here tbh
 }
 
 #endif // _CODEWRITER_H

M projects/08/src/parser.h → projects/08/src/parser.h

@@ -73,9 +73,9 @@ vm_instr->arg1 = NULL;
 	return true;
 }
 
-void print_vm_instruction(struct vm_instruction_t *vm_instr)
+void print_vm_instruction(struct vm_instruction_t *vm_instr, FILE *fp)
 {
-	printf("{\n\tcmd: %d,\n\targ1: \"%s\",\n\targ2: %hu,\n}\n",
+	fprintf(fp, "{\n\tcmd: %d,\n\targ1: \"%s\",\n\targ2: %hu,\n}\n",
 	        vm_instr->cmd, vm_instr->arg1, vm_instr->arg2);
 }