diff --git a/.gitignore b/.gitignore
index b0ab508..d14260a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,9 @@
 *.obj
 *.elf
 
+# Debugger
+*.pdb
+
 # Linker output
 *.ilk
 *.map
diff --git a/include/fatals.h b/include/fatals.h
index 335cd43..2230462 100644
--- a/include/fatals.h
+++ b/include/fatals.h
@@ -1,8 +1,10 @@
 #ifndef ACC_FATALS_H
 #define ACC_FATALS_H
 
-#include "noreturn.h"
+#include <stddef.h>
+#include <stdnoreturn.h>
 
+void* malloc_or_fail(size_t s, const char *func_name);
 noreturn void fail_malloc(const char *func_name);
 noreturn void fail_ast_op(int op, const char *func_name);
 noreturn void fail_ce_expect(const char *expected, const char *got);
diff --git a/include/noreturn.h b/include/noreturn.h
deleted file mode 100644
index 169bcc8..0000000
--- a/include/noreturn.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef ACC_NORETURN_H
-#define ACC_NORETURN_H
-
-#define noreturn _Noreturn
-
-#endif
\ No newline at end of file
diff --git a/include/token.h b/include/token.h
index 54e16a6..d4fc1cc 100644
--- a/include/token.h
+++ b/include/token.h
@@ -19,9 +19,9 @@ enum {
 	T_EQ, T_NE, T_LT, T_GT, T_LE, T_GE,
 	T_INT, T_VOID, T_CHAR, T_LONG,
 	T_PRINT, T_IF, T_ELSE, T_WHILE, T_FOR,
-	T_INTLIT, T_LONGLIT, T_INDENT,
+	T_I32_LIT, T_I64_LIT, T_INDENT,
 };
-extern const char *token_typename[29];
+extern const char *token_typename[63];
 
 void token_free(struct token *t);
 struct token token_make_eof(void);
diff --git a/include/util/linklist.h b/include/util/linklist.h
index 80c95bc..c65d000 100644
--- a/include/util/linklist.h
+++ b/include/util/linklist.h
@@ -13,13 +13,19 @@ struct linklist {
 };
 
 struct llist_node* llist_createnode(void *val);
-void llist_pushback(struct linklist *l, void *val);
-void llist_pushback_notnull(struct linklist *l, void *val);
-void* llist_get(struct linklist *l, int x);
-void llist_set(struct linklist *l, int x, void *val);
+
 void llist_init(struct linklist *l);
 void llist_free(struct linklist *l);
+void llist_free_full(struct linklist *l);
+
+void llist_pushback(struct linklist *l, void *val);
+void llist_pushback_notnull(struct linklist *l, void *val);
+
+void* llist_get(struct linklist *l, int x);
+void llist_set(struct linklist *l, int x, void *val);
+
 void llist_insert(struct linklist *l, int x, void *val);
-void llist_popfront(struct linklist *l);
+void* llist_popfront(struct linklist *l);
+void* llist_remove(struct linklist *l, int index);
 
 #endif
diff --git a/include/util/misc.h b/include/util/misc.h
index f2ddde6..008fabf 100644
--- a/include/util/misc.h
+++ b/include/util/misc.h
@@ -1,7 +1,9 @@
 #ifndef ACC_UTIL_MISC_H
 #define ACC_UTIL_MISC_H
 
-int strequal(const char *s1, const char *s2);
+#include <stdbool.h>
+
+bool strequal(const char *s1, const char *s2);
 char *strclone(const char *s);
 
 #endif
diff --git a/src/ast.c b/src/ast.c
index 81b7e3b..436aa8f 100644
--- a/src/ast.c
+++ b/src/ast.c
@@ -6,10 +6,7 @@
 
 // Build and return a binary AST node
 struct ASTnode* ast_make_binary(int op, struct ASTnode *left, struct ASTnode *right) {
-	struct ASTbinnode *x = malloc(sizeof(struct ASTbinnode));
-	if (x == NULL) {
-		fail_malloc(__FUNCTION__);
-	}
+	struct ASTbinnode *x = malloc_or_fail(sizeof(struct ASTbinnode), __FUNCTION__);
 
 	x->op = op;
 	x->left = left;
@@ -19,10 +16,7 @@ struct ASTnode* ast_make_binary(int op, struct ASTnode *left, struct ASTnode *ri
 
 // Make an AST int literal node
 struct ASTnode* ast_make_intlit(int val) {
-	struct ASTintnode *x = malloc(sizeof(struct ASTintnode));
-	if (x == NULL) {
-		fail_malloc(__FUNCTION__);
-	}
+	struct ASTintnode *x = malloc_or_fail(sizeof(struct ASTintnode), __FUNCTION__);
 
 	x->op = A_INTLIT;
 	x->val = val;
@@ -31,10 +25,7 @@ struct ASTnode* ast_make_intlit(int val) {
 
 // Make an AST variable value node
 struct ASTnode* ast_make_var(int id) {
-	struct ASTvarnode *x = malloc(sizeof(struct ASTvarnode));
-	if (x == NULL) {
-		fail_malloc(__FUNCTION__);
-	}
+	struct ASTvarnode *x = malloc_or_fail(sizeof(struct ASTvarnode), __FUNCTION__);
 
 	x->op = A_VAR;
 	x->id = id;
@@ -43,10 +34,7 @@ struct ASTnode* ast_make_var(int id) {
 
 // Make a unary AST node: only one child
 struct ASTnode* ast_make_unary(int op, struct ASTnode *c) {
-	struct ASTunnode *x = malloc(sizeof(struct ASTunnode));
-	if (x == NULL) {
-		fail_malloc(__FUNCTION__);
-	}
+	struct ASTunnode *x = malloc_or_fail(sizeof(struct ASTunnode), __FUNCTION__);
 
 	x->op = op;
 	x->c = c;
@@ -55,10 +43,7 @@ struct ASTnode* ast_make_unary(int op, struct ASTnode *c) {
 
 // Make a block ast node
 struct ASTnode* ast_make_block() {
-	struct ASTblocknode *x = malloc(sizeof(struct ASTblocknode));
-	if (x == NULL) {
-		fail_malloc(__FUNCTION__);
-	}
+	struct ASTblocknode *x = malloc_or_fail(sizeof(struct ASTblocknode), __FUNCTION__);
 
 	x->op = A_BLOCK;
 	llist_init(&x->st);
@@ -67,10 +52,7 @@ struct ASTnode* ast_make_block() {
 
 // Make a assignment ast node
 struct ASTnode* ast_make_assign(int op, int left, struct ASTnode *right) {
-	struct ASTassignnode *x = malloc(sizeof(struct ASTassignnode));
-	if (x == NULL) {
-		fail_malloc(__FUNCTION__);
-	}
+	struct ASTassignnode *x = malloc_or_fail(sizeof(struct ASTassignnode), __FUNCTION__);
 
 	x->op = op;
 	x->left = left;
@@ -80,10 +62,7 @@ struct ASTnode* ast_make_assign(int op, int left, struct ASTnode *right) {
 
 // Make a if statement ast node
 struct ASTnode* ast_make_if(struct ASTnode *left, struct ASTnode *right, struct ASTnode *cond) {
-	struct ASTifnode *x = malloc(sizeof(struct ASTifnode));
-	if (x == NULL) {
-		fail_malloc(__FUNCTION__);
-	}
+	struct ASTifnode *x = malloc_or_fail(sizeof(struct ASTifnode), __FUNCTION__);
 
 	x->op = A_IF;
 	x->left = left;
diff --git a/src/cg_llvm.c b/src/cg_llvm.c
index 7a4977b..f569caa 100644
--- a/src/cg_llvm.c
+++ b/src/cg_llvm.c
@@ -53,7 +53,7 @@ static int cgcomp_i(int x, int y, char *op, char *ty) {
 	int r1 = alloc_tag();
 	fprintf(Outfile, "\t%%%d = icmp %s %s %%%d, %%%d\n", r1, op, ty, x, y);
 	int r2 = alloc_tag();
-	if (ty[0] != 'i' || ty[1] != '1' || ty[2] != '\0') {
+	if (strcmp(ty, "i1") != 0) { // special case for bool
 		fprintf(Outfile, "\t%%%d = zext i1 %%%d to %s\n", r2, r1, ty);
 	}
 	return (r2);
diff --git a/src/fatals.c b/src/fatals.c
index f9dba62..4816afe 100644
--- a/src/fatals.c
+++ b/src/fatals.c
@@ -7,6 +7,14 @@ void fail_malloc(const char *func_name) {
 	exit(1);
 }
 
+void* malloc_or_fail(size_t s, const char *func_name) {
+	void *res = malloc(s);
+	if (res == NULL) {
+		fail_malloc(func_name);
+	}
+	return (res);
+}
+
 void fail_ast_op(int op, const char *func_name) {
 	fprintf(stderr, "%s: unknown ast operator %d.\n", func_name, op);
 	exit(1);
diff --git a/src/parse.c b/src/parse.c
index 2259866..3486517 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -1,5 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdbool.h>
+#include <stdint.h>
 #include "scan.h"
 #include "token.h"
 #include "ast.h"
@@ -42,10 +44,10 @@ static int arithop(int t) {
 		{T_GT,		A_GT},
 		{T_GE,		A_GE},
 		{T_ASSIGN,	A_ASSIGN},
-		{T_EOF}
+		{-1}
 	};
 
-	for (int i = 0; map[i][0] != T_EOF; ++i) {
+	for (int i = 0; map[i][0] != -1; ++i) {
 		if (t == map[i][0]) {
 			return map[i][1];
 		}
@@ -54,22 +56,21 @@ static int arithop(int t) {
 }
 
 // operator ssociativity direction
-// Return	0 if left to right, e.g. +
-// 		1 if right to left, e.g. =
-static int direction_rtl(int t) {
+// Returns	false if left to right, e.g. +
+// 			true if right to left, e.g. =
+static bool direction_rtl(int t) {
 	switch(t) {
 		case T_ASSIGN:
-			return (1);
+			return (true);
 		default:
-			return (0);
+			return (false);
 	}
 }
 
 // Next token
 static void next(void) {
 	if (Tokens.head) {
-		token_free(Tokens.head->val);
-		llist_popfront(&Tokens);
+		token_free(llist_popfront(&Tokens));
 	}
 }
 
@@ -78,7 +79,8 @@ static struct token preview(int k) {
 	if (Tokens.length <= k) {
 		return (token_make_eof());
 	}
-	return (*((struct token*)llist_get(&Tokens, k)));
+	struct token* res = llist_get(&Tokens, k);
+	return (*res);
 }
 
 // return current token from input stream
@@ -117,12 +119,12 @@ static struct ASTnode* primary(void) {
 		next();
 		res = expression();
 		match(T_RP);
-	} else if (current().type == T_INTLIT) {
-		res = ast_make_intlit(*((int*)current().val));
+	} else if (current().type == T_I32_LIT) {
+		res = ast_make_intlit(*(int32_t*)current().val);
 		next();
-	} else if (current().type == T_LONGLIT) {
+	} else if (current().type == T_I64_LIT) {
 		// todo
-		fprintf(stderr, "TOOD.\n");
+		fprintf(stderr, "TOOD: T_I64_LIT.\n");
 		exit(1);
 	} else if (current().type == T_INDENT) {
 		int id = findglob((char*)current().val);
@@ -296,29 +298,24 @@ static struct ASTnode* for_statement(void) {
 
 // parse one statement
 static struct ASTnode* statement(void) {
-	if (current().type == T_SEMI) {
-		return (NULL);
-	}
-	else if (current().type == T_PRINT) {
-		return (print_statement());
-	}
-	else if (current().type == T_INT) {
-		return (var_declaration());
-	}
-	else if (current().type == T_IF) {
-		return (if_statement());
-	}
-	else if (current().type == T_WHILE) {
-		return (while_statement());
-	}
-	else if (current().type == T_FOR) {
-		return (for_statement());
-	}
-	else {
-		skip_semi = 0;
-		struct ASTnode* res = expression();
-		match(T_SEMI);
-		return (res);
+	switch (current().type) {
+		case T_SEMI:
+			return (NULL);
+		case T_PRINT:
+			return (print_statement());
+		case T_INT:
+			return (var_declaration());
+		case T_IF:
+			return (if_statement());
+		case T_WHILE:
+			return (while_statement());
+		case T_FOR:
+			return (for_statement());
+		default:
+			skip_semi = 0;
+			struct ASTnode* res = expression();
+			match(T_SEMI);
+			return (res);
 	}
 }
 
diff --git a/src/scan.c b/src/scan.c
index 392cc07..d7a2c3a 100644
--- a/src/scan.c
+++ b/src/scan.c
@@ -1,8 +1,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
-#include <limits.h>
 #include <string.h>
+#include <stdbool.h>
+#include <stdint.h>
 #include "token.h"
 #include "fatals.h"
 #include "util/misc.h"
@@ -11,18 +12,6 @@ int Line = 1;
 static int Preview;
 static FILE *Infile;
 
-const char *token_typename[] = {
-	"EOF",
-	";",
-	"{", "}", "(", ")",
-	"=",
-	"+", "-", "*", "/",
-	"==", "!=", "<", ">", "<=", ">=",
-	"int", "void", "char", "long",
-	"print", "if", "else", "while", "for",
-	"an integer literal (type int)", "an integer literal (type long)", "an indentifier"
-};
-
 // preview one char, not getting it out from the stream
 static int preview(void) {
 	if (!Preview) {
@@ -43,9 +32,7 @@ static void next(void) {
 // Skip past input that we don't need to deal with,
 // i.e. whitespace, newlines.
 static void skip_whitespaces(void) {
-	int c;
-
-	c = preview();
+	int c = preview();
 	while (c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f') {
 		next();
 		c = preview();
@@ -53,7 +40,7 @@ static void skip_whitespaces(void) {
 }
 
 // Scan and return an integer literal value from the input file.
-static void scanint(struct token *t) {
+static void scan_int(struct token *t) {
 	long long res = 0;
 	int c = preview();
 	while ('0' <= c && c <= '9') {
@@ -62,40 +49,35 @@ static void scanint(struct token *t) {
 		c = preview();
 	}
 
-	if (INT_MIN <= res && res <= INT_MAX) {
-		t->type = T_INTLIT;
-		t->val = malloc(sizeof(int));
-		if (t->val == NULL) {
-			fail_malloc(__FUNCTION__);
-		}
-		*((int *)t->val) = (int)res;
+	if (INT32_MIN <= res && res <= INT32_MAX) {
+		t->type = T_I32_LIT;
+		t->val = malloc_or_fail(sizeof(int32_t), __FUNCTION__);
+		*((int32_t *)t->val) = (int)res;
 	} else {
-		t->type = T_LONGLIT;
-		t->val = malloc(sizeof(long long));
-		if (t->val == NULL) {
-			fail_malloc(__FUNCTION__);
-		}
-		*((long long *)t->val) = res;
+		t->type = T_I64_LIT;
+		t->val = malloc_or_fail(sizeof(int64_t), __FUNCTION__);
+		*((int64_t *)t->val) = res;
 	}
 }
 
 // Scan an identifier from the input file and
-// Return the identifier (char*)
+// Return the identifier string (char*)
+// Writes the length into _n_ or NULL
 static char* scan_indentifier(int *n) {
 	int sz = 128, len = 0;
 
-	char *res = malloc(sz * sizeof(char));
+	char *res = malloc_or_fail(sz * sizeof(char), __FUNCTION__);
 	memset(res, 0, sz * sizeof(char));
 
 	int c = preview();
 	while (isdigit(c) || isalpha(c) || c == '_') {
 		if (len >= sz - 1) {
 			sz *= 2;
-			char *old = res;
-			res = malloc(sz * sizeof(char));
-			memcpy(res, old, len * sizeof(char));
+			char *res = realloc(res, sz * sizeof(char));
+			if (res == NULL) {
+				fail_malloc(__FUNCTION__);
+			}
 			memset(res + len * sizeof(char), 0, (sz - len) * sizeof(char));
-			free(old);
 		}
 		res[len++] = c;
 		next();
@@ -108,8 +90,9 @@ static char* scan_indentifier(int *n) {
 	return (res);
 }
 
-// Given a word from the input, scan if it is a keyword
-static int scan_keyword(struct token *t, char *s) {
+// Given a word from the input, scan if it is a keyword.
+// Returns true if found keyword.
+static bool scan_keyword(struct token *t, char *s) {
 	static const char *map_s[] = {
 		"print",
 		"int",
@@ -137,15 +120,15 @@ static int scan_keyword(struct token *t, char *s) {
 	for (int i = 0; map_s[i] != NULL; ++i) {
 		if (strequal(map_s[i], s)) {
 			t->type = map_t[i];
-			return (1);
+			return (true);
 		}
 	}
-	return (0);
+	return (false);
 }
 
 // Scan one char token
 // Return 1 if found
-static int scan_1c(struct token *t) {
+static bool scan_1c(struct token *t) {
 	static const int map[][2] = {
 		{'+', T_PLUS},
 		{'-', T_MINUS},
@@ -164,18 +147,15 @@ static int scan_1c(struct token *t) {
 		if (map[i][0] == c) {
 			t->type = map[i][1];
 			next();
-			return (1);
+			return (true);
 		}
 	}
-	return (0);
+	return (false);
 }
 
 // Scan and return the next token found in the input.
 static struct token* scan(void) {
-	struct token *t = malloc(sizeof(struct token));
-	if (t == NULL) {
-		fail_malloc(__FUNCTION__);
-	}
+	struct token *t = malloc_or_fail(sizeof(struct token), __FUNCTION__);
 	t->val = NULL;
 
 	skip_whitespaces();
@@ -204,8 +184,7 @@ static struct token* scan(void) {
 			t->type = T_NE;
 			next();
 		} else {
-			fprintf(stderr, "Unrecognised character %c on line %d.\n", c, Line);
-			exit(1);
+			fail_char(c);
 		}
 	} else if (c == '<') {
 		t->type = T_LT;
@@ -226,7 +205,7 @@ static struct token* scan(void) {
 	} else {
 		// If it's a digit, scan the integer literal value in
 		if (isdigit(c)) {
-			scanint(t);
+			scan_int(t);
 		} else if (isalpha(c) || c == '_') {
 			t->val = scan_indentifier(NULL);
 			if (scan_keyword(t, t->val)) {
diff --git a/src/token.c b/src/token.c
index fdd07c4..4e3f4da 100644
--- a/src/token.c
+++ b/src/token.c
@@ -2,6 +2,18 @@
 #include <stdio.h>
 #include "token.h"
 
+const char *token_typename[63] = {
+	"EOF",
+	";",
+	"{", "}", "(", ")",
+	"=",
+	"+", "-", "*", "/",
+	"==", "!=", "<", ">", "<=", ">=",
+	"int", "void", "char", "long",
+	"print", "if", "else", "while", "for",
+	"a signed integer literal (size 32)", "a signed integer literal (size 64)", "an indentifier"
+};
+
 void token_free(struct token *t) {
 	if (t->val) {
 		free(t->val);
diff --git a/src/util/linklist.c b/src/util/linklist.c
index 3aba276..1a920a7 100644
--- a/src/util/linklist.c
+++ b/src/util/linklist.c
@@ -3,6 +3,7 @@
 #include "fatals.h"
 #include "util/linklist.h"
 
+// Create a linklist node using given value.
 struct llist_node* llist_createnode(void *val) {
 	struct llist_node *res = malloc(sizeof(struct llist_node));
 	if (res == NULL) {
@@ -13,6 +14,7 @@ struct llist_node* llist_createnode(void *val) {
 	return (res);
 }
 
+// Appends an element in the linklist. 
 void llist_pushback(struct linklist *l, void *val) {
 	l->length += 1;
 	if (!l->tail) {
@@ -23,44 +25,51 @@ void llist_pushback(struct linklist *l, void *val) {
 	l->tail = l->tail->nxt;
 }
 
+// A variant of pushback
+// Only does pushback if _val_ is not null.
 void llist_pushback_notnull(struct linklist *l, void *val) {
 	if (val) {
 		llist_pushback(l, val);
 	}
 }
 
-void* llist_get(struct linklist *l, int x) {
-	if (x >= l->length) {
+// Returns the _index_ thh element.
+void* llist_get(struct linklist *l, int index) {
+	if (index >= l->length) {
 		fprintf(stderr, "linklist out of range.\n");
 		abort();
 	}
 
 	struct llist_node *p = l->head;
-	for (int i = 0; i < x; ++i) {
+	for (int i = 0; i < index; ++i) {
 		p = p->nxt;
 	}
 	return (p->val);
 }
 
-void llist_set(struct linklist *l, int x, void *val) {
-	if (x >= l->length) {
+// Modify the _index_ thh element.
+void llist_set(struct linklist *l, int index, void *val) {
+	if (index >= l->length) {
 		fprintf(stderr, "linklist out of range.\n");
 		abort();
 	}
 
 	struct llist_node *p = l->head;
-	for (int i = 0; i < x; ++i) {
+	for (int i = 0; i < index; ++i) {
 		p = p->nxt;
 	}
 	p->val = val;
 }
 
+// Init a empty linklist.
 void llist_init(struct linklist *l) {
 	l->length = 0;
 	l->head = NULL;
 	l->tail = NULL;
 }
 
+// Frees the linklist.
+// Caller must make sure all elements in the linklist has already been freed. 
 void llist_free(struct linklist *l) {
 	struct llist_node *p = l->head;
 	struct llist_node *nxt;
@@ -72,6 +81,24 @@ void llist_free(struct linklist *l) {
 	llist_init(l);
 }
 
+// Frees the linklist.
+// Callee will free all elements in the link list.
+void llist_free_full(struct linklist *l) {
+	struct llist_node *p = l->head;
+	struct llist_node *nxt;
+	while (p) {
+		nxt = p->nxt;
+		if (p->val) {
+			free(p->val);
+		}
+		free(p);
+		p = nxt;
+	}
+	llist_init(l);
+}
+
+// Insert _val_ into the linklist as the _index_ th element.
+// If _index_ is too large, pushback only!
 void llist_insert(struct linklist *l, int index, void *val) {
 	if (index >= l->length) {
 		llist_pushback(l, val);
@@ -94,18 +121,46 @@ void llist_insert(struct linklist *l, int index, void *val) {
 	p->nxt = x;
 }
 
-void llist_popfront(struct linklist *l) {
+// Pop the first element of the link list
+// Return the first element.
+void* llist_popfront(struct linklist *l) {
 	if (l->head == NULL) {
-		return;
+		return (NULL);
 	}
 
 	l->length -= 1;
+	void *res = l->head->val;
 	if (l->length == 0) {
 		free(l->head);
 		l->head = l->tail = NULL;
+		return (res);
 	}
 
 	struct llist_node *p = l->head;
 	l->head = p->nxt;
 	free(p);
+	return (res);
+}
+
+// Removes the _index_ th element from the linklist.
+// Returns the removed value.
+void* llist_remove(struct linklist *l, int index) {
+	if (index >= l->length) {
+		return (NULL);
+	}
+	
+	if (index == 0) {
+		return (llist_popfront(l));
+	}
+	
+	l->length -= 1;
+	struct llist_node *p = l->head;
+	for (int i = 0; i < index - 2; ++i) {
+		p = p->nxt;
+	}
+	struct llist_node *q = p->nxt;
+	p->nxt = q->nxt;
+	void *res = q->val;
+	free(q);
+	return res;
 }
diff --git a/src/util/misc.c b/src/util/misc.c
index cf6a2f7..85c03ea 100644
--- a/src/util/misc.c
+++ b/src/util/misc.c
@@ -1,22 +1,15 @@
 #include <string.h>
 #include <stdlib.h>
+#include "util/misc.h"
 
 // check if two string are the same
-int strequal(const char *s1, const char *s2) {
-	for (int i = 1; ; ++i) {
-		if (s1[i] != s2[i]) {
-			return (0);
-		}
-
-		if (s1[i] == '\0') {
-			break;
-		}
-	}
-	return (1);
+bool strequal(const char *s1, const char *s2) {
+	return (strcmp(s1, s2) == 0);
 }
 
 // A impl of C23 strdup()
-char* strclone(char *s) {
+// Clones the given string
+char* strclone(const char *s) {
 	int n = strlen(s);
 	char *res = malloc(n + 1);
 	memcpy(res, s, n * sizeof(char));
diff --git a/tests/out.input01 b/tests/input01.ans
similarity index 100%
rename from tests/out.input01
rename to tests/input01.ans
diff --git a/tests/out.input02 b/tests/input02.ans
similarity index 100%
rename from tests/out.input02
rename to tests/input02.ans
diff --git a/tests/out.input03 b/tests/input03.ans
similarity index 100%
rename from tests/out.input03
rename to tests/input03.ans
diff --git a/tests/out.input04 b/tests/input04.ans
similarity index 100%
rename from tests/out.input04
rename to tests/input04.ans
diff --git a/tests/out.input05 b/tests/input05.ans
similarity index 100%
rename from tests/out.input05
rename to tests/input05.ans
diff --git a/tests/out.input06 b/tests/input06.ans
similarity index 100%
rename from tests/out.input06
rename to tests/input06.ans
diff --git a/tests/out.input07 b/tests/input07.ans
similarity index 100%
rename from tests/out.input07
rename to tests/input07.ans
diff --git a/tests/test_llvm.lua b/tests/test_llvm.lua
new file mode 100644
index 0000000..036b4fa
--- /dev/null
+++ b/tests/test_llvm.lua
@@ -0,0 +1,50 @@
+local acc_path = nil
+for _, path in ipairs({ "../acc", "../acc.exe", "../acc.out" }) do
+	if os.exists(path) then
+		acc_path = path
+	end
+end
+
+if acc_path == nil then
+	error("acc executable not found.")
+end
+
+local function compare_file(p1, p2)
+	local f1 = io.open(p1, "r");
+	local f2 = io.open(p2, "r");
+	repeat
+		local l1 = f1:read()
+		local l2 = f2:read()
+		if l1 ~= l2 then
+			f1:close()
+			f2:close()
+			return false
+		end
+	until l1 == nil
+	f1:close()
+	f2:close()
+	return true
+end
+
+for _, input in ipairs(os.files("tests/input*")) do
+	if input:endswith(".ans") then
+		goto continue
+	end
+
+	local ans = input .. ".ans"
+	if not os.exists(ans) then
+		cprint("${orange} [WARN] not found answer for case %s.", input)
+		goto continue
+	end
+	os.run("acc llvm %s out.ll", input)
+	os.run("clang out.ll -o test.exe")
+	local output = os.iorun("test.exe")
+	local output_path = os.tmpfile()
+	io.writefile(output_path, output)
+	if compare_file(output_path, ans) then
+		cprint("${green} [INFO] case %s: OK.", input)
+	else
+		cprint("${red} [INFO] case %s: FAILED.", input)
+	end
+	::continue::
+end
diff --git a/tests/test_llvm.sh b/tests/test_llvm.sh
deleted file mode 100644
index dfca175..0000000
--- a/tests/test_llvm.sh
+++ /dev/null
@@ -1,30 +0,0 @@
-#!/bin/sh
-# Run each test and compare
-# against known good output
-
-set -e
-
-echo "Testing for target llvm..."
-
-if [ ! -f ../acc ]
-then echo "Need to build ../acc first!"; exit 1
-fi
-
-for i in input*
-do if [ ! -f "out.$i" ]
-   then echo "Can't run test on $i, no answer file!"
-   else
-     echo -n $i
-     ../acc llvm $i
-     clang -o out out.ll -w
-     ./out > trial.$i
-     cmp -s "out.$i" "trial.$i"
-     if [ "$?" -eq "1" ]
-     then echo ": failed"
-       diff -c "out.$i" "trial.$i"
-       echo
-     else echo ": OK"
-     fi
-     rm -f out out.ll "trial.$i"
-   fi
-done
diff --git a/tests/test_x64.sh b/tests/test_x64.sh
deleted file mode 100644
index f081768..0000000
--- a/tests/test_x64.sh
+++ /dev/null
@@ -1,30 +0,0 @@
-#!/bin/sh
-# Run each test and compare
-# against known good output
-
-set -e
-
-echo "Testing for target x86_64..."
-
-if [ ! -f ../acc ]
-then echo "Need to build ../acc first!"; exit 1
-fi
-
-for i in input*
-do if [ ! -f "out.$i" ]
-   then echo "Can't run test on $i, no answer file!"
-   else
-     echo -n $i
-     ../acc x86_64 $i
-     gcc -o out out.s
-     ./out > trial.$i
-     cmp -s "out.$i" "trial.$i"
-     if [ "$?" -eq "1" ]
-     then echo ": failed"
-       diff -c "out.$i" "trial.$i"
-       echo
-     else echo ": OK"
-     fi
-     rm -f out out.s "trial.$i"
-   fi
-done