save and load compiled vmbl files

src/vmbl.c

@@ -1,5 +1,7 @@
 #include "vmbl.h"
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 VMBL_Exception VBML_ExecuteInstruction(VMBL_State *vmblState, VMBL_Instruction instruction) {
 	switch (instruction.type)
@@ -21,8 +23,34 @@ VMBL_Exception VBML_ExecuteInstruction(VMBL_State *vmblState, VMBL_Instruction i
 		vmblState->stackSize--;
 		break;
 
-	default:
+	case INSTRUCTION_DUPLICATE:
+		if (vmblState->stackSize - instruction.opperand <= 0) {
+			return (VMBL_Exception){ EXCEPTION_STACK_UNDERFLOW };
+		}
 
+		if (vmblState->stackSize >= VMBL_STACK_SIZE) {
+			return (VMBL_Exception){ EXCEPTION_STACK_OVERFLOW };
+		}
+		
+		if (instruction.opperand < 0) {
+			return (VMBL_Exception) { EXCEPTION_INVALID_OPPERAND };
+		}
+		
+		vmblState->stack[vmblState->stackSize++] = vmblState->stack[vmblState->stackSize - 1 - instruction.opperand];
+
+		break;
+
+	case INSTRUCTION_JUMP:
+
+		vmblState->ip = instruction.opperand;
+
+		break;
+
+	case INSTRUCTION_HALT:
+		vmblState->halted = true;
+		break;
+
+	default:
 		return (VMBL_Exception) { EXCEPTION_INVALID_OPCODE };
 		break;
 	}
@@ -36,10 +64,115 @@ void VMBL_Dump(VMBL_State vmblState, VMBL_Exception exception) {
 
 	if (vmblState.stackSize > 0) {
 		for (size_t i = 0; i < vmblState.stackSize; i++) {
-				fprintf(stderr, "    0x%lX: %ld\n", i, vmblState.stack[i]);
+				fprintf(stderr, "    0x%lX: 0x%ld\n", i, vmblState.stack[i]);
 		}
 	} else {
 		fprintf(stderr, "    [empty]\n");
 	}
 	
+}
+
+void VMBL_StartVM(VMBL_State *vmblState) {
+	for (;;)
+	{
+		// fetch next instruction
+		if (vmblState->ip >= VMBL_PROGRAM_SIZE) {
+			VMBL_Dump(*vmblState, (VMBL_Exception){ EXCEPTION_INVALID_INSTRUCTION_ACCESS});
+			return;
+		}
+
+		
+		VMBL_Instruction instruction = vmblState->program[vmblState->ip++];
+		printf("%s 0x%lx\n", instructionTypeToCStr(instruction.type), instruction.opperand);
+		
+		VMBL_Exception exception = VBML_ExecuteInstruction(vmblState, instruction);
+
+		if (exception.type != EXCEPTION_NONE) {
+			VMBL_Dump(*vmblState, exception);
+			return;
+		}
+
+		if (vmblState->halted) {
+			return;
+		}
+		 
+	}
+	
+}
+
+
+// executable operations
+void VMBL_LoadExecutable(VMBL_State *vmblState, VMBL_Instruction *program, size_t programSize) {
+	if (programSize > VMBL_PROGRAM_SIZE) {
+		fprintf(stderr, "VMBL: failed to load program from memory because it is %ld words in size, while the max size is %d.", programSize, VMBL_PROGRAM_SIZE);
+		exit(1);
+	}
+
+	memcpy(vmblState->program, program, sizeof(program[0]) * programSize);
+
+	vmblState->programSize = programSize;
+}
+
+void VMBL_LoadExecutableFromFile(VMBL_State *vmblState, const char* filePath) {
+	FILE *file = fopen(filePath, "rb");
+
+	if (file == NULL) {
+		perror("VMBL: Failed to open file");
+		exit(1);
+	}
+
+	fseek(file, 0, SEEK_END);
+	long size = ftell(file);
+	rewind(file);
+
+	size_t programSize = size / sizeof(vmblState->program[0]);
+	VMBL_Instruction program[programSize];
+	fread(program, sizeof(program[0]), programSize, file);
+
+	VMBL_LoadExecutable(vmblState, program, programSize);
+
+	fclose(file);
+	
+}
+
+void VMBL_SaveExecutable(const char* filePath, VMBL_Instruction *program, size_t programSize) {
+	FILE *file = fopen(filePath, "wb");
+
+	if (file == NULL) {
+		perror("VMBL: Failed to open file");
+		exit(1);
+	}
+
+	fwrite(program, sizeof(program[0]), programSize, file);
+	fclose(file);
+}
+
+char *instructionTypeToCStr(InstructionType type) {
+	switch (type)
+	{
+
+	case INSTRUCTION_PUSH:
+		return "PUSH";
+		break;
+
+	case INSTRUCTION_ADD:
+		return "ADD ";
+		break;
+
+	case INSTRUCTION_DUPLICATE:
+		return "DUP ";
+		break;
+		
+	case INSTRUCTION_JUMP:
+		return "JMP ";
+		break;
+
+	case INSTRUCTION_HALT:
+		return "HALT";
+		break;
+	
+	default:
+		return "??? ";
+		break;
+	}
 }