add a way to test dissassembling of .asm files automatically

src/asm.c

@@ -6,51 +6,15 @@
 #define u16 uint16_t
 #define u8  uint8_t
 
-struct cpu_state {
-    u16 ax, bx, cx, dx, sp, bp, si, di;
-};
+const char *wide_reg_names[8]     = { "ax", "cx", "dx", "bx", "sp", "bp", "si", "di" };
+const char *non_wide_reg_names[8] = { "al", "cl", "dl", "bl", "ah", "ch", "dh", "bh" };
 
 const char *lookup_reg_name(u8 idx, bool wide) {
     if (wide) {
-        if        (idx == 0b000) {
-            return "ax";
-        } else if (idx == 0b001) {
-            return "cx";
-        } else if (idx == 0b010) {
-            return "dx";
-        } else if (idx == 0b011) {
-            return "bx";
-        } else if (idx == 0b100) {
-            return "sp";
-        } else if (idx == 0b101) {
-            return "bp";
-        } else if (idx == 0b110) {
-            return "si";
-        } else if (idx == 0b111) {
-            return "di";
-        }
+        return wide_reg_names[idx];
     } else {
-        if        (idx == 0b000) {
-            return "al";
-        } else if (idx == 0b001) {
-            return "cl";
-        } else if (idx == 0b010) {
-            return "dl";
-        } else if (idx == 0b011) {
-            return "bl";
-        } else if (idx == 0b100) {
-            return "ah";
-        } else if (idx == 0b101) {
-            return "ch";
-        } else if (idx == 0b110) {
-            return "dh";
-        } else if (idx == 0b111) {
-            return "bh";
-        }
+        return non_wide_reg_names[idx];
     }
-
-    printf("ERROR: Unknown register %d, wide %d", idx, wide);
-    abort();
 }
 
 void dissassemble(FILE *src, FILE *dst) {
@@ -59,6 +23,7 @@ void dissassemble(FILE *src, FILE *dst) {
         u8 byte1 = fgetc(src);
         u8 byte2 = fgetc(src);
 
+        // Register memory to/from register
         if ((byte1 & 0b11111100) == 0b10001000) {
             bool wide = byte1 & 0b1;
             bool direction = (byte1 & 0b10) >> 1;

src/main.c

@@ -1,9 +1,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <fcntl.h>
+#include <string.h>
 #include "os.h"
-#include "cpu.c"
 #include <errno.h>
+#include "asm.c"
+
+#define strequal(a, b) strcmp(a, b) == 0
 
 const char *get_tmp_dir() {
 #ifdef IS_WINDOWS
@@ -17,6 +20,24 @@ const char *get_tmp_dir() {
 #endif
 }
 
+int strendswith(const char *str, const char *suffix)
+{
+    if (!str || !suffix)
+        return 0;
+    size_t lenstr = strlen(str);
+    size_t lensuffix = strlen(suffix);
+    if (lensuffix >  lenstr)
+        return 0;
+    return strncmp(str + lenstr - lensuffix, suffix, lensuffix) == 0;
+}
+
+char *strdup(const char *src) {
+    char *dst = malloc(strlen (src) + 1);
+    if (dst == NULL) return NULL;
+    strcpy(dst, src);
+    return dst;
+}
+
 void get_tmp_file(char *filename, const char *prefix) {
 	const char *dir = get_tmp_dir();
 	sprintf(filename, "%s\\%sXXXXXX", dir, prefix);
@@ -24,28 +45,124 @@ void get_tmp_file(char *filename, const char *prefix) {
 	close(fd);
 }
 
-int main() {
-	char tmp_filename[MAX_PATH_SIZE];
-	get_tmp_file(tmp_filename, "nasm_output");
-
-	char *example_filename = "examples/many_register_mov.asm";
+void print_usage(const char *program) {
+	fprintf(stderr, "Usage: %s <test|dump> <file>\n", program);
+}
 
+int compile_asm(const char *src, const char *dst) {
 	char command[512] = { 0 };
-	snprintf(command, sizeof(command), "nasm \"%s\" -o \"%s\"", example_filename, tmp_filename);
-	if (system(command)) {
-		printf("ERROR: Failed to compile '%s'", example_filename);
+	snprintf(command, sizeof(command), "nasm \"%s\" -o \"%s\"", src, dst);
+	return system(command);
+}
+
+int compare_files(const char *expected, const char *gotten) {
+	int rc = -1;
+	FILE *f1 = fopen(expected, "r");
+	FILE *f2 = fopen(gotten, "r");
+
+	int i = 0;
+	while (!feof(f1) && !feof(f2)) {
+		int byte1 = fgetc(f1);
+		int byte2 = fgetc(f2);
+		if (byte1 != byte2) {
+			printf("Mismatch byte at %d, expected %d got %d\n", i, byte1, byte2);
+			goto err;
+		}
+		i++;
+	}
+
+	if (!feof(f1) || !feof(f2)) {
+
+		goto err;
+	}
+
+	rc = 0;
+err:
+	fclose(f1);
+	fclose(f2);
+	return rc;
+}
+
+int main(int argc, char **argv) {
+	if (argc != 3) {
+		print_usage(argv[0]);
 		return -1;
 	}
 
-	FILE *assembly = fopen(tmp_filename, "r");
-	if (assembly == NULL) {
-		printf("ERROR: Opening file '%s': %d\n", tmp_filename, errno);
+	if (strequal(argv[1], "test")) {
+		char *asm_file = argv[2];
+		if (!strendswith(asm_file, ".asm")) {
+			printf("ERROR: Expected *.asm file, gotten '%s'", asm_file);
+			return -1;
+		}
+
+		char *bin_filename = "test-input.o";
+		if (compile_asm(asm_file, bin_filename)) {
+			printf("ERROR: Failed to compile '%s'", asm_file);
+			return -1;
+		}
+
+		FILE *bin_test = fopen(bin_filename, "rb");
+		if (bin_test == NULL) {
+			printf("ERROR: Opening file '%s': %d\n", bin_filename, errno);
+			return -1;
+		}
+
+		char *dissassembly_filename = "test-dump.asm";
+		FILE *dissassembly = fopen(dissassembly_filename, "wb+");
+		if (dissassembly == NULL) {
+			printf("ERROR: Opening file '%s': %d\n", dissassembly_filename, errno);
+			return -1;
+		}
+		dissassemble(bin_test, dissassembly);
+		fclose(dissassembly);
+
+		char *dissassembly_dump_filename = "test-dump-asm.o";
+		if (compile_asm(dissassembly_filename, dissassembly_dump_filename)) {
+			printf("ERROR: Failed to compile '%s'", dissassembly_filename);
+			return -1;
+		}
+
+		if (!compare_files(bin_filename, dissassembly_dump_filename)) {
+			printf("Test success\n");
+		} else {
+			printf("Test failed\n");
+		}
+
+	} else if (strequal(argv[1], "dump")) {
+		char *input_file = argv[2];
+
+		if (strendswith(input_file, ".asm")) {
+			char bin_filename[MAX_PATH_SIZE];
+			get_tmp_file(bin_filename, "nasm_output");
+
+			if (compile_asm(input_file, bin_filename)) {
+				printf("ERROR: Failed to compile '%s'", input_file);
+				return -1;
+			}
+
+			FILE *assembly = fopen(bin_filename, "r");
+			if (assembly == NULL) {
+				printf("ERROR: Opening file '%s': %d\n", bin_filename, errno);
+				return -1;
+			}
+			dissassemble(assembly, stdout);
+
+			remove(bin_filename);
+		} else {
+			FILE *assembly = fopen(input_file, "r");
+			if (assembly == NULL) {
+				printf("ERROR: Opening file '%s': %d\n", input_file, errno);
+				return -1;
+			}
+			dissassemble(assembly, stdout);
+			fclose(assembly);
+		}
+
+	} else {
+		print_usage(argv[0]);
 		return -1;
 	}
-	dissassemble(assembly, stdout);
-	fclose(assembly);
-
-	remove(tmp_filename);
 
 	return 0;
 }

test-dump-asm.o

@@ -0,0 +1 @@
+菓

test-dump.asm

@@ -0,0 +1,3 @@
+bits 16
+
+mov cx, bx

test-input.o

@@ -0,0 +1 @@
+菓