main function(AST)

Signed-off-by: szdytom <szdytom@163.com>

README.md

@@ -1,33 +1,3 @@
 # acc
-A zero-dependence (sub) C compiler working in progress written in pure ISO C11.
+A (WIP) zero-dependence (sub) C compiler written in pure ISO C11, minimal but aims to implement all 4 passes(lex, parse, build ir, code generation) and a set of machine-independent optimizations.
 
-## Build from source
-
-Make sure you have `gcc` and `make` on your PATH.
-If you don't, here's command for ubuntu:
-
-```
-sudo apt install build-essential
-```
-
-To build, run:
-```
-make
-```
-
-## Usage
-
-```
-acc target inputfile (outputfile)
-```
-
-Output targets now includes:
-- `x86_64`: Intel's x84-64 ASM
-- `llvm`: LLVM's IR
-- `ast`: (used for debugging) Abstruct Syntax Tree 
-
-Example:
-
-```
-acc x86_64 test.c
-```

include/ast.h

@@ -9,41 +9,38 @@ enum {
 	A_ASSIGN,
 	A_ADD, A_SUB, A_MUL, A_DIV,
 	A_EQ, A_NE, A_LT, A_GT, A_LE, A_GE,
-	A_LIT, A_VAR,
+	A_LIT_I32, A_LIT_I64,
+	A_VAR,
 	A_BLOCK,
 	A_PRINT, A_IF, A_WHILE,
+	A_RETURN,
 	A_SOUL // what?
 };
 
-// value type
+extern const char *ast_opname[31];
-enum {
-	V_I32, V_I64, V_BOOL
-};
 
-struct value_type {
+// AST structure field shared by all types 
-	int vt; // base value type
+// llist_node *n	: for linklist
-};
+// int op		: node operation
-
+#define ASTnode_SHARED_FIELDS \
-// AST nodde types
+	struct llist_node n; \
-enum {
+	int op;
-	N_BIN, N_UN, N_MULTI, N_LEAF, N_ASSIGN
-};
 
 // AST structure (common)
 struct ASTnode {
-	int op;	//operator
+	ASTnode_SHARED_FIELDS 
 };
 
 // AST binary operation node
 struct ASTbinnode {
-	int op;
+	ASTnode_SHARED_FIELDS 
 	struct ASTnode *left;
 	struct ASTnode *right;
 };
 
 // AST if statement node
 struct ASTifnode {
-	int op;
+	ASTnode_SHARED_FIELDS 
 	struct ASTnode *left;	// condition true branch
 	struct ASTnode *right;	// condition false branch
 	struct ASTnode *cond;
@@ -51,33 +48,38 @@ struct ASTifnode {
 
 // AST unary operation node
 struct ASTunnode {
-	int op;
+	ASTnode_SHARED_FIELDS 
-	struct ASTnode *c;
+	struct ASTnode *left;
 };
 
 // AST block node
 struct ASTblocknode {
-	int op;
+	ASTnode_SHARED_FIELDS 
 	struct linklist st; // statements linklist
 };
 
-// AST literal node
+// AST integer literal (32bit) node
-struct ASTlitnode {
+struct ASTi32node {
-	int op;
+	ASTnode_SHARED_FIELDS 
-	struct value_type type;
+	int32_t val;
-	void *val;
+};
+
+// AST integer literal (64bit) node
+struct ASTi64node {
+	ASTnode_SHARED_FIELDS 
+	int64_t val;
 };
 
 // AST assign literal node
 struct ASTassignnode {
-	int op;
+	ASTnode_SHARED_FIELDS 
-	int left;
+	struct ASTnode* left;
 	struct ASTnode* right;
 };
 
 // AST variable value node
 struct ASTvarnode {
-	int op;
+	ASTnode_SHARED_FIELDS 
 	int id;
 };
 
@@ -87,9 +89,8 @@ struct ASTnode* ast_make_lit_i64(int64_t x);
 struct ASTnode* ast_make_unary(int op, struct ASTnode *c);
 struct ASTnode* ast_make_block();
 struct ASTnode* ast_make_var(int id);
-struct ASTnode* ast_make_assign(int op, int left, struct ASTnode *right);
+struct ASTnode* ast_make_assign(int op, struct ASTnode *left, struct ASTnode *right);
 struct ASTnode* ast_make_if(struct ASTnode *left, struct ASTnode *right, struct ASTnode *cond);
-int ast_type(int t);
 void ast_free(struct ASTnode *x);
 
 #endif

include/cg.h

@@ -1,29 +0,0 @@
-#ifndef ACC_CG_H
-#define ACC_CG_H
-
-#include "ast.h"
-
-extern FILE *Outfile;
-
-// cg.c
-void cg_main(int target, struct ASTnode *rt);
-void open_outputfile(char *filename);
-void cg_unload(void);
-
-// cg_x64.c
-//void cgx64_generate(struct ASTnode *rt);
-
-// cg_llvm.c
-//void cgllvm_generate(struct ASTnode *rt);
-
-// cg_ast.c
-void cgast_generate(struct ASTnode *rt);
-
-// targets
-enum {
-	CG_X64,		// Intel x86_64
-	CG_LLVM,		// LLVM IR
-	CG_AST,		// Abstruct Syntax Tree
-};
-
-#endif

include/fatals.h

@@ -5,6 +5,7 @@
 #include <stdnoreturn.h>
 
 void* malloc_or_fail(size_t s, const char *func_name);
+noreturn void fail_target(const char *target_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);

include/print_ast.h

@@ -0,0 +1,7 @@
+#ifndef ACC_DEBUG_PRINT_AST
+#define ACC_DEBUG_PRINT_AST
+
+void debug_ast_print(FILE *Outfile, struct ASTnode *rt);
+
+#endif
+

include/scan.h

@@ -1,7 +1,7 @@
 #ifndef ACC_SCAN_H
 #define ACC_SCAN_H
 
-#include "token.h"
+#include "util/linklist.h"
 
 extern int Line;
 struct linklist scan_tokens(const char *name);

include/symbol.h

@@ -1,3 +1,4 @@
+/*
 #ifndef ACC_SYMBOL_H
 #define ACC_SYMBOL_H
 
@@ -11,3 +12,4 @@ int findglob(char *s);
 int addglob(char *s);
 
 #endif
+*/

include/target.h

@@ -0,0 +1,11 @@
+#ifndef ACC_TARGET_H
+#define ACC_TARGET_H
+
+// Target types
+enum {
+	TARGET_AST
+};
+
+int target_parse(const char *target_string);
+
+#endif

include/token.h

@@ -1,29 +1,41 @@
 #ifndef ACC_TOKEN_H
 #define ACC_TOKEN_H
 
+#include <stdint.h>
 #include "util/linklist.h"
 
 // Token structure
 struct token {
+	struct llist_node n;
 	int type;	// token type
-	void* val;	// hold the value of the literal that we scanned in
+	union {		// hold the value of the literal that we scanned in
+		int16_t val_i16;
+		int32_t val_i32;
+		int64_t val_i64;
+		char *val_s;
+	};
 };
 
 // Tokens
 enum {
 	T_EOF,
-	T_SEMI,
+	T_SEMI,					// ;
-	T_LB, T_RB, T_LP, T_RP,
+	T_LB, T_RB, T_LP, T_RP,			// { } ( )
-	T_ASSIGN,
+	T_ASSIGN,				// =
-	T_PLUS, T_MINUS, T_STAR, T_SLASH,
+	T_PLUS, T_MINUS, T_STAR, T_SLASH,	// + - * /
-	T_EQ, T_NE, T_LT, T_GT, T_LE, T_GE,
+	T_EQ, T_NE, T_LT, T_GT, T_LE, T_GE,	// == != < > <= >=
-	T_INT, T_VOID, T_CHAR, T_LONG,
+	T_INT, T_VOID, T_CHAR, T_LONG,		// int void char long
-	T_PRINT, T_IF, T_ELSE, T_WHILE, T_FOR,
+	T_SHORT,				// short
-	T_I32_LIT, T_I64_LIT, T_INDENT,
+	T_PRINT, T_IF, T_ELSE,			// print if else
+	T_WHILE, T_FOR,				// while for
+	T_RETURN,				// return
+	T_I16_LIT, T_I32_LIT, T_I64_LIT,
+	T_ID,
+	T_EXCEED,
 };
 extern const char *token_typename[63];
 
 void token_free(struct token *t);
-struct token token_make_eof(void);
 
 #endif
+

include/util/hashmap.h

@@ -1,3 +1,4 @@
+/*
 #ifndef ACC_UTIL_HASHMAP
 #define ACC_UTIL_HASHMAP
 
@@ -9,4 +10,5 @@ struct hashmap {
 
 void hashmap_init();
 
-#endif
+#endif
+*/

include/util/linklist.h

@@ -2,7 +2,6 @@
 #define ACC_UTIL_LINKLIST_H
 
 struct llist_node {
-	void *val;
 	struct llist_node *nxt;
 };
 
@@ -12,8 +11,6 @@ struct linklist {
 	struct llist_node *tail;
 };
 
-struct llist_node* llist_createnode(void *val);
-
 void llist_init(struct linklist *l);
 void llist_free(struct linklist *l);
 void llist_free_full(struct linklist *l);

main.c

@@ -3,9 +3,9 @@
 #include <string.h>
 #include "scan.h"
 #include "parse.h"
-#include "cg.h"
 #include "ast.h"
-#include "symbol.h"
+#include "target.h"
+#include "print_ast.h"
 
 // Print out a usage if started incorrectly
 static void usage(char *prog) {
@@ -14,48 +14,29 @@ static void usage(char *prog) {
 	exit(1);
 }
 
-//Do clean up job
+// Do clean up job
 void unload(void) {
-	cg_unload();
-	symbol_unload();
 }
 
 int main(int argc, char *argv[]) {
-	atexit(unload);
+//	atexit(unload);
 	if (argc < 3) {
 		usage(argv[0]);
 	}
 
-	int outfile_opened = 0;
+	FILE *Outfile;
 	if (argc >= 4) {
-		open_outputfile(argv[3]);
+		Outfile = fopen(argv[3], "w");
-		outfile_opened = 1;
-	}
-
-	int target;
-	if (!strcmp(argv[1], "x86_64")) {
-		target = CG_X64;
-		if (!outfile_opened) {
-			open_outputfile("out.s");
-		}
-	} else if (!strcmp(argv[1], "llvm")) {
-		target = CG_LLVM;
-		if (!outfile_opened) {
-			open_outputfile("out.ll");
-		}
-	} else if (!strcmp(argv[1], "ast")) {
-		target = CG_AST;
-		if (!outfile_opened) {
-			open_outputfile("out.txt");
-		}
 	} else {
-		fprintf(stderr, "Unknow target %s.\n", argv[1]);
+		Outfile = fopen("out.txt", "w");
-		exit(1);
 	}
 
-	symbol_init();
+	int target = target_parse(argv[1]);
 	struct ASTnode *rt = parse(argv[2]);
-	cg_main(target, rt);
+	if (target == TARGET_AST) {
+		debug_ast_print(Outfile, rt);
+	}
 	ast_free(rt);
+	fclose(Outfile);
 	return (0);
 }

src/ast.c

@@ -4,6 +4,18 @@
 #include "fatals.h"
 #include "util/linklist.h"
 
+const char *ast_opname[] = {
+	"=",
+	"+", "-", "*", "/",
+	"==", "!=", "<", ">", "<=", ">=",
+	"int32", "int64",
+	"var",
+	"block",
+	"print", "if", "while",
+	"return",
+	NULL
+};
+
 // Build and return a binary AST node
 struct ASTnode* ast_make_binary(int op, struct ASTnode *left, struct ASTnode *right) {
 	struct ASTbinnode *x = malloc_or_fail(sizeof(struct ASTbinnode), __FUNCTION__);
@@ -14,25 +26,21 @@ struct ASTnode* ast_make_binary(int op, struct ASTnode *left, struct ASTnode *ri
 	return ((struct ASTnode*)x);
 }
 
-// Make an AST int32 literal node
+// Make an AST integer literal (32bit) node
 struct ASTnode* ast_make_lit_i32(int32_t v) {
-	struct ASTlitnode *x = malloc_or_fail(sizeof(struct ASTlitnode), __FUNCTION__);
+	struct ASTi32node *x = malloc_or_fail(sizeof(struct ASTi32node), __FUNCTION__);
 
-	x->op = A_LIT;
+	x->op = A_LIT_I32;
-	x->type.vt = V_I32;
+	x->val = v;
-	x->val = malloc_or_fail(sizeof(int32_t), __FUNCTION__);
-	*(int64_t*)x->val = v;
 	return ((struct ASTnode*)x);
 }
 
-// Make an AST int32 literal node
+// Make an AST integer literal (64bit) node
 struct ASTnode* ast_make_lit_i64(int64_t v) {
-	struct ASTlitnode *x = malloc_or_fail(sizeof(struct ASTlitnode), __FUNCTION__);
+	struct ASTi64node *x = malloc_or_fail(sizeof(struct ASTi64node), __FUNCTION__);
 
-	x->op = A_LIT;
+	x->op = A_LIT_I64;
-	x->type.vt = V_I64;
+	x->val = v;
-	x->val = malloc_or_fail(sizeof(int64_t), __FUNCTION__);
-	*(int64_t*)x->val = v;
 	return ((struct ASTnode*)x);
 }
 
@@ -46,11 +54,11 @@ 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 ASTnode* ast_make_unary(int op, struct ASTnode *child) {
 	struct ASTunnode *x = malloc_or_fail(sizeof(struct ASTunnode), __FUNCTION__);
 
 	x->op = op;
-	x->c = c;
+	x->left = child;
 	return ((struct ASTnode*)x);
 }
 
@@ -64,7 +72,7 @@ struct ASTnode* ast_make_block() {
 }
 
 // Make a assignment ast node
-struct ASTnode* ast_make_assign(int op, int left, struct ASTnode *right) {
+struct ASTnode* ast_make_assign(int op, struct ASTnode *left, struct ASTnode *right) {
 	struct ASTassignnode *x = malloc_or_fail(sizeof(struct ASTassignnode), __FUNCTION__);
 
 	x->op = op;
@@ -84,66 +92,44 @@ struct ASTnode* ast_make_if(struct ASTnode *left, struct ASTnode *right, struct
 	return ((struct ASTnode*)x);
 }
 
-// Translate ast operation type to ast node type
-int ast_type(int t) {
-	switch (t) {
-	case A_ADD: case A_SUB: case A_MUL: case A_DIV:
-	case A_EQ: case A_NE: case A_GT: case A_LT: case A_GE: case A_LE:
-	case A_IF: case A_WHILE:
-		return (N_BIN);
-	case A_ASSIGN:
-		return (N_ASSIGN);
-	case A_LIT: case A_VAR:
-		return (N_LEAF);
-	case A_BLOCK:
-		return (N_MULTI);
-	case A_PRINT:
-		return (N_UN);
-	default:
-		fail_ast_op(t, __FUNCTION__);
-	}
-}
-
 // free an AST's memory
 void ast_free(struct ASTnode *x) {
 	if (x == NULL) {
 		return;
 	}
 
-	switch (ast_type(x->op)) {
+	switch (x->op) {
-	case N_ASSIGN: {
+		case A_IF: {
-		struct ASTassignnode *t = (struct ASTassignnode*)x;
-		ast_free(t->right);
-	}	break;
-	case N_BIN: {
-		struct ASTbinnode *t = (struct ASTbinnode*)x;
-		ast_free(t->left);
-		ast_free(t->right);
-		if (x->op == A_IF) {
 			ast_free(((struct ASTifnode*)x)->cond);
-		}
+		}	// dont break
-	}	break;
+
-	case N_UN: {
+		case A_ASSIGN:
-		struct ASTunnode *t = (struct ASTunnode*)x;
+		case A_ADD: case A_SUB: case A_MUL: case A_DIV:
-		ast_free(t->c);
+		case A_EQ: case A_NE: case A_GT: case A_LT: case A_GE: case A_LE:
-	}	break;
+		case A_WHILE: {
-	case N_MULTI: {
+			struct ASTbinnode *t = (struct ASTbinnode*)x;
-		struct ASTblocknode *t = (struct ASTblocknode*)x;
+			ast_free(t->left);
-		struct llist_node *p = t->st.head;
+			ast_free(t->right);
-		while (p) {
+		}	break;
-			ast_free(p->val);
+	
-			p = p->nxt;
+		case A_PRINT: case A_RETURN: {
-		}
+			struct ASTunnode *t = (struct ASTunnode*)x;
-		llist_free(&t->st);
+			ast_free(t->left);
-	}	break;
+		}	break;
-	case N_LEAF: {
+
-		struct ASTlitnode *t = (struct ASTlitnode*)x;
+		case A_BLOCK: {
-		if (t->op == A_LIT) {
+			struct ASTblocknode *t = (struct ASTblocknode*)x;
-			if (t->val) {
+			struct llist_node *p = t->st.head, *nxt;
-				free(t->val);
+			while (p) {
+				nxt = p->nxt;
+				ast_free(p);
+				p = nxt;
 			}
-		}
+			llist_free(&t->st);
-	}	break;
+		}	break;
+
+		default: {
+		}	break;
 	}
 	free(x);
 }

src/cg.c

@@ -1,38 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <errno.h>
-#include <string.h>
-#include "cg.h"
-
-FILE *Outfile;
-
-// open output file of generated code
-void open_outputfile(char *filename) {
-	Outfile = fopen(filename, "w");
-	if (Outfile == NULL) {
-		fprintf(stderr, "Unable to open %s: %s\n", filename, strerror(errno));
-		exit(1);
-	}
-}
-
-// close Outfile at exit.
-void cg_unload(void) {
-	if (Outfile) {
-		fclose(Outfile);
-	}
-}
-
-// generates code
-void cg_main(int target, struct ASTnode *rt) {
-	if (target == CG_X64) {
-		//cgx64_generate(rt);
-	} else if (target == CG_LLVM) {
-		//cgllvm_generate(rt);
-	} else if (target == CG_AST) {
-		cgast_generate(rt);
-	} else {
-		fprintf(stderr, "Unknow target %d.\n", target);
-		exit(1);
-	}
-}
-

src/cg_ast.c

@@ -1,119 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include "ast.h"
-#include "cg.h"
-#include "symbol.h"
-#include "fatals.h"
-#include "util/array.h"
-
-static const char *ast_opname[] = {
-	"=",
-	"+", "-", "*", "/",
-	"==", "!=", "<", ">", "<=", ">=",
-	"int", "var",
-	"block",
-	"print", "if", "while"
-};
-
-static int tabs;
-
-static void cgprint_tabs() {
-	for (int i = 0; i < tabs; ++i) {
-		fprintf(Outfile, "\t");
-	}
-}
-
-static void cgenerate_dfs(struct ASTnode *x) {
-	if (x == NULL) {
-		cgprint_tabs();
-		fprintf(Outfile, "--->NULL.\n");
-		return;
-	}
-
-	int nt = ast_type(x->op);
-	if (nt == N_LEAF) {
-		if (x->op == A_LIT) {
-			struct ASTlitnode *t = (struct ASTlitnode*)x;
-			cgprint_tabs();
-			switch (t->type.vt) {
-			case V_I32:
-				fprintf(Outfile, "--->INT %d.\n", *(int32_t*)t->val);
-				break;
-			case V_I64:
-				fprintf(Outfile, "--->INT64 %lld.\n", *(int64_t*)t->val);
-				break;
-			default:
-				fprintf(stderr, "%s: Unknow literal type %d.\n", __FUNCTION__, t->type.vt);
-				exit(1);
-			}
-		} else if (x->op == A_VAR) {
-			struct ASTvarnode *t = (struct ASTvarnode*)x;
-			cgprint_tabs();
-			fprintf(Outfile, "--->VAR @%s.\n", (char*)array_get(&Gsym, t->id));
-		} else {
-			fail_ast_op(x->op, __FUNCTION__);
-		}
-	} else if (nt == N_ASSIGN) {
-		struct ASTassignnode *t = (struct ASTassignnode*)x;
-		cgprint_tabs();
-		fprintf(Outfile, "--->ASSIGN(%s) to @%s (right)\n", ast_opname[t->op], (char*)array_get(&Gsym, t->left));
-		tabs += 1;
-		cgenerate_dfs(t->right);
-		tabs -= 1;
-	} else if (nt == N_BIN) {
-		if (x->op == A_IF) {
-			struct ASTifnode *t = (struct ASTifnode*)x;
-			cgprint_tabs();
-			fprintf(Outfile, "--->IF (cond left right)\n");
-			tabs += 1;
-			cgenerate_dfs(t->cond);
-			cgenerate_dfs(t->left);
-			cgenerate_dfs(t->right);
-			tabs -= 1;
-		} else if (x->op == A_WHILE) {
-			struct ASTbinnode *t = (struct ASTbinnode*)x;
-			cgprint_tabs();
-			fprintf(Outfile, "--->WHILE(%s) (cond body)\n", ast_opname[t->op]);
-			tabs += 1;
-			cgenerate_dfs(t->left);
-			cgenerate_dfs(t->right);
-			tabs -= 1;
-		} else {
-			struct ASTbinnode *t = (struct ASTbinnode*)x;
-			cgprint_tabs();
-			fprintf(Outfile, "--->BINOP(%s) (left right)\n", ast_opname[t->op]);
-			tabs += 1;
-			cgenerate_dfs(t->left);
-			cgenerate_dfs(t->right);
-			tabs -= 1;
-		}
-	} else if (nt == N_UN) {
-		if (x->op == A_PRINT) {
-			struct ASTunnode *t = (struct ASTunnode*)x;
-			cgprint_tabs();
-			fprintf(Outfile, "--->PRINT (value)\n");
-			tabs += 1;
-			cgenerate_dfs(t->c);
-			tabs -= 1;
-		} else {
-			fail_ast_op(x->op, __FUNCTION__);
-		}
-	} else if (nt == N_MULTI) {
-		struct ASTblocknode *t = (struct ASTblocknode*)x;
-		cgprint_tabs();
-		fprintf(Outfile, "--->BLOCK (%d childs)\n", t->st.length);
-		tabs += 1;
-		struct llist_node *p = t->st.head;
-		while (p) {
-			cgenerate_dfs(p->val);
-			p = p->nxt;
-		}
-		tabs -= 1;
-	}
-}
-
-void cgast_generate(struct ASTnode *rt) {
-	tabs = 0;
-	cgenerate_dfs(rt);
-}
-

src/cg_llvm.c

@@ -1,216 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include "ast.h"
-#include "cg.h"
-#include "symbol.h"
-#include "fatals.h"
-#include "util/array.h"
-#include "util/linklist.h"
-
-static int alloc_tag(void) {
-	static int id = 0;
-	return (id++);
-}
-
-static int alloc_label(void) {
-	static int id = 0;
-	return (id++);
-}
-
-// Print out the ir preamble
-static void cgpreamble(void) {
-	fputs(	"@.printint.format = constant [4 x i8] c\"%d\\0A\\00\", align 1\n"
-		"declare dso_local i32 @printf(i8* readonly nocapture, ...)\n"
-		"define dso_local void @printint(i32 %0) {\n"
-		"\t%2 = getelementptr inbounds [4 x i8], [4 x i8]* @.printint.format, i32 0, i32 0\n"
-		"\t%3 = call i32 (i8*, ...) @printf(i8* %2, i32 %0)\n"
-		"\tret void\n"
-		"}\n"
-		"\n"
-		"define dso_local i32 @main() {\n"
-		"entry:\n", Outfile);
-}
-
-// Print out the ir postamble
-static void cgpostamble(void) {
-	fputs("\tret i32 0\n}\n", Outfile);
-}
-
-// init as global value
-static void cginit_glob(char *name) {
-	fprintf(Outfile, "@%s = dso_local global i32 0, align 4\n", name);
-}
-
-// Preform arithmetic operation between two i32
-static int cgarith_i32(int x, int y, char *op) {
-	int r = alloc_tag();
-	fprintf(Outfile, "\t%%%d = %s i32 %%%d, %%%d\n", r, op, x, y);
-	return (r);
-}
-
-// Preform comparision between integers
-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 (strcmp(ty, "i1") != 0) { // special case for bool
-		fprintf(Outfile, "\t%%%d = zext i1 %%%d to %s\n", r2, r1, ty);
-	}
-	return (r2);
-}
-
-// Preform comparision between two i32
-static int cgcomp_i32(int x, int y, char *op) {
-	return (cgcomp_i(x, y, op, "i32"));
-}
-
-// Load an int literal
-static int cgload_lit_i32(int val) {
-	int r = alloc_tag();
-	fprintf(Outfile, "\t%%%d = select i1 true, i32 %d, i32 undef\n", r, val);
-	return (r);
-}
-
-// Load an int from a global variable
-static int cgload_glob_i32(char *name) {
-	int r = alloc_tag();
-	fprintf(Outfile, "\t%%%d = load i32, i32* @%s, align 4\n", r, name);
-	return (r);
-}
-
-// Store an int into a global variable
-static int cgstore_glob_i32(int x, char *name) {
-	fprintf(Outfile, "\tstore i32 %%%d, i32* @%s, align 4\n", x, name);
-	return (x);
-}
-
-// Print a i32
-static void cgprint(int x) {
-	fprintf(Outfile, "\tcall void (i32) @printint(i32 %%%d)\n", x);
-}
-
-// Jump to a label no matter what
-static void cgjmp_always(int x) {
-	fprintf(Outfile, "\tbr label %%L%d\n", x);
-}
-
-// Conditional jump
-static void cgjmp_if_i32(int cond, int Lthen, int Lelse) {
-	int rc = alloc_tag();
-	fprintf(Outfile, "\t%%%d = icmp ne i32 0, %%%d\n", rc, cond);
-	fprintf(Outfile, "\tbr i1 %%%d, label %%L%d, label %%L%d\n", rc, Lthen, Lelse);
-}
-
-static void cgprint_label(int L) {
-	fprintf(Outfile, "L%d:\n", L);
-}
-
-// generates llvm ir from ast
-static int cgenerate_ast(struct ASTnode *rt) {
-	int nt = ast_type(rt->op);
-	if (nt == N_LEAF) {
-		if (rt->op == A_INTLIT) {
-			return (cgload_lit_i32(((struct ASTintnode*)rt)->val));
-		} else if (rt->op == A_VAR) {
-			return (cgload_glob_i32(array_get(&Gsym, ((struct ASTvarnode*)rt)->id)));
-		}
-		fail_ast_op(rt->op, __FUNCTION__);
-	} else if (nt == N_BIN) {
-		if (rt->op == A_IF) {
-			struct ASTifnode *x = (struct ASTifnode*)rt;
-			int Lthen = alloc_label(), Lelse = alloc_label(), Lend = alloc_label();
-			int condv = cgenerate_ast(x->cond);
-			cgjmp_if_i32(condv, Lthen, Lelse);
-
-			cgprint_label(Lthen);
-			cgenerate_ast(x->left);
-			cgjmp_always(Lend);
-
-			cgprint_label(Lelse);
-			cgenerate_ast(x->right);
-			cgjmp_always(Lend);
-
-			cgprint_label(Lend);
-			return (-1);
-		} else if (rt->op == A_WHILE) {
-			struct ASTbinnode *x = (struct ASTbinnode*)rt;
-			int Lstart = alloc_label(), Lbody = alloc_label(), Lend = alloc_label();
-			cgjmp_always(Lstart);
-
-			cgprint_label(Lstart);
-			int condv = cgenerate_ast(x->left);
-			cgjmp_if_i32(condv, Lbody, Lend);
-
-			cgprint_label(Lbody);
-			cgenerate_ast(x->right);
-			cgjmp_always(Lstart);
-
-			cgprint_label(Lend);
-			return (-1);
-		}
-
-		struct ASTbinnode *x = (struct ASTbinnode*)rt;
-		int lc = cgenerate_ast(x->left);
-		int rc = cgenerate_ast(x->right);
-
-		if (rt->op == A_ADD) {
-			return (cgarith_i32(lc, rc, "add nsw"));
-		} else if (rt->op == A_SUB) {
-			return (cgarith_i32(lc, rc, "sub nsw"));
-		} else if (rt->op == A_MUL) {
-			return (cgarith_i32(lc, rc, "mul nsw"));
-		} else if (rt->op == A_DIV) {
-			return (cgarith_i32(lc, rc, "sdiv"));
-		} else if (rt->op == A_EQ) {
-			return (cgcomp_i32(lc, rc, "eq"));
-		} else if (rt->op == A_NE) {
-			return (cgcomp_i32(lc, rc, "ne"));
-		} else if (rt->op == A_GT) {
-			return (cgcomp_i32(lc, rc, "sgt"));
-		} else if (rt->op == A_GE) {
-			return (cgcomp_i32(lc, rc, "sge"));
-		} else if (rt->op == A_LT) {
-			return (cgcomp_i32(lc, rc, "slt"));
-		} else if (rt->op == A_LE) {
-			return (cgcomp_i32(lc, rc, "sle"));
-		}
-		fail_ast_op(rt->op, __FUNCTION__);
-	} else if (nt == N_UN) {
-		struct ASTunnode *x = (struct ASTunnode*)rt;
-		int cv = cgenerate_ast(x->c);
-
-		if (rt->op == A_PRINT) {
-			cgprint(cv);
-			return (-1);
-		}
-		fail_ast_op(rt->op, __FUNCTION__);
-	} else if (nt == N_ASSIGN) {
-		struct ASTassignnode *x = (struct ASTassignnode*)rt;
-		int cv = cgenerate_ast(x->right);
-
-		if (rt->op == A_ASSIGN) {
-			return (cgstore_glob_i32(cv, array_get(&Gsym, x->left)));
-		}
-		fail_ast_op(rt->op, __FUNCTION__);
-	} else if (nt == N_MULTI) {
-		struct ASTblocknode *x = (struct ASTblocknode*)rt;
-		int val = -1;
-		struct llist_node *p = x->st.head;
-		while (p) {
-			val = cgenerate_ast(p->val);
-			p = p->nxt;
-		}
-		return val;
-	}
-	fail_ast_op(rt->op, __FUNCTION__);
-}
-
-// generate and write ir to Outfile
-void cgllvm_generate(struct ASTnode* rt) {
-	for (int i = 0; i < Gsym.length; ++i) {
-		cginit_glob(array_get(&Gsym, i));
-	}
-	cgpreamble();
-	cgenerate_ast(rt);
-	cgpostamble();
-}

src/fatals.c

@@ -2,6 +2,11 @@
 #include <stdlib.h>
 #include "scan.h"
 
+void fail_target(const char *target_name) {
+	fprintf(stderr, "unknown target: %s.\n", target_name);
+	exit(1);
+}
+
 void fail_malloc(const char *func_name) {
 	fprintf(stderr, "%s: unable to malloc.\n", func_name);
 	exit(1);

src/parse.c

@@ -5,11 +5,9 @@
 #include "scan.h"
 #include "token.h"
 #include "ast.h"
-#include "symbol.h"
 #include "fatals.h"
 
 static struct linklist Tokens;	// current token for parsing
-static int skip_semi = 0;	// can skip statement semi (after block)
 
 // Check that we have a binary operator and return its precedence.
 // operators with larger precedence value will be evaluated first
@@ -57,7 +55,7 @@ static int arithop(int t) {
 
 // operator ssociativity direction
 // Returns	false if left to right, e.g. +
-// 			true if right to left, e.g. =
+// 		true if right to left, e.g. =
 static bool direction_rtl(int t) {
 	switch(t) {
 		case T_ASSIGN:
@@ -77,10 +75,12 @@ static void next(void) {
 // preview next kth token from input stream
 static struct token* preview(int k) {
 	if (Tokens.length <= k) {
-		static struct token token_eof;
+		static struct token token_eof = {
-		token_eof = token_make_eof();
+			.type = T_EOF
+		};
 		return (&token_eof);
 	}
+
 	struct token* res = llist_get(&Tokens, k);
 	return (res);
 }
@@ -92,9 +92,7 @@ static struct token* current(void) {
 
 // match a token or report syntax error
 static void match(int t) {
-	if (t == T_SEMI && skip_semi) {
+	if (current()->type == t) {
-		skip_semi = 0;
-	} else if (current()->type == t) {
 		next();
 	} else {
 		fail_ce_expect(token_typename[current()->type], token_typename[t]);
@@ -102,7 +100,7 @@ static void match(int t) {
 }
 
 // check current token's type or report syntax error.
-static void check(int t) {
+static void expect(int t) {
 	if (current()->type != t) {
 		fail_ce_expect(token_typename[current()->type], token_typename[t]);
 	}
@@ -122,11 +120,14 @@ static struct ASTnode* primary(void) {
 		res = expression();
 		match(T_RP);
 	} else if (current()->type == T_I32_LIT) {
-		res = ast_make_lit_i32(*(int32_t*)current()->val);
+		res = ast_make_lit_i32(current()->val_i32);
 		next();
 	} else if (current()->type == T_I64_LIT) {
-		res = ast_make_lit_i64(*(int64_t*)current()->val);
+		res = ast_make_lit_i64(current()->val_i64);
-	} else if (current()->type == T_INDENT) {
+		next();
+	} else if (current()->type == T_ID) {
+		// TODO: identifier.
+		/*
 		int id = findglob((char*)current()->val);
 		if (id == -1) {
 			fprintf(stderr, "syntax error on line %d: unknown indentifier %s.\n", Line, (char*)current()->val);
@@ -134,6 +135,9 @@ static struct ASTnode* primary(void) {
 		}
 		next();
 		return (ast_make_var(id));
+		*/
+		res = NULL;
+		next();
 	} else {
 		fprintf(stderr, "syntax error on line %d: primary expression excpeted.\n", Line);
 		exit(1);
@@ -178,7 +182,7 @@ static struct ASTnode* binexpr(int precedence) {
 }
 
 // parse one block of code, e.g. { a; b; }
-static struct ASTnode* parse_block(void) {
+static struct ASTnode* block(void) {
 	match(T_LB);
 	if (current()->type == T_RB) {
 		next();
@@ -196,15 +200,15 @@ static struct ASTnode* parse_block(void) {
 		}
 	}
 	match(T_RB);
-	skip_semi = 1;
 	return ((struct ASTnode*)res);
 }
 
 // parse an expression
 static struct ASTnode* expression(void) {
-	if (current()->type == T_LB) {
+	if (current()->type == T_SEMI) {
-		return (parse_block());
+		return (NULL);
 	}
+
 	return (binexpr(0));
 }
 
@@ -216,10 +220,11 @@ static struct ASTnode* print_statement(void) {
 	return (res);
 }
 
+/*
 // parse variable declaration statement
 static struct ASTnode* var_declaration(void) {
 	match(T_INT);
-	check(T_INDENT);
+	expect(T_IDENT);
 	if (findglob((char*)current()->val) != -1) {
 		fail_ce("variable declared twice.");
 	}
@@ -228,6 +233,7 @@ static struct ASTnode* var_declaration(void) {
 	match(T_SEMI);
 	return (NULL);
 }
+*/
 
 // parse an if statement
 static struct ASTnode* if_statement(void) {
@@ -284,6 +290,10 @@ static struct ASTnode* for_statement(void) {
 
 	if (body == NULL && inc == NULL) {
 		wbody = NULL;
+	} else if (body == NULL) {
+		wbody = inc;
+	} else if (inc == NULL) {
+		wbody = body;
 	} else {
 		struct ASTblocknode* wt = (struct ASTblocknode*)ast_make_block();
 		llist_pushback_notnull(&wt->st, body);
@@ -293,40 +303,80 @@ static struct ASTnode* for_statement(void) {
 
 	llist_pushback_notnull(&container->st, init);
 	llist_pushback(&container->st, ast_make_binary(A_WHILE, cond, wbody));
-	return (struct ASTnode*)container;
+	return ((struct ASTnode*)container);
+}
+
+static struct ASTnode* return_statement() {
+	match(T_RETURN);
+	struct ASTnode *res = expression();
+	match(T_SEMI);
+	return (ast_make_unary(A_RETURN, res));
 }
 
 // parse one statement
 static struct ASTnode* statement(void) {
 	switch (current()->type) {
+		case T_LB:
+			return (block());
+
 		case T_SEMI:
 			return (NULL);
+
 		case T_PRINT:
 			return (print_statement());
-		case T_INT:
+
-			return (var_declaration());
+//		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;
+		case T_RETURN:
+			return (return_statement());
+
+		default: {
 			struct ASTnode* res = expression();
 			match(T_SEMI);
 			return (res);
+		}
 	}
 }
 
+// Parse one top-level function
+// Sets the func_name param.
+static struct ASTnode* function(char **func_name) {
+	match(T_INT);
+	expect(T_ID);
+	*func_name = current()->val_s;	// transfer ownership of the identifier string to caller
+	current()->val_s = NULL;	// prevent it from being freed in token_free() called by next.
+	next();
+
+	match(T_LP);
+	if (current()->type == T_VOID) {
+		next();
+		goto END_PARAM_LIST;
+	}
+	// TODO: param list
+
+END_PARAM_LIST:
+	match(T_RP);
+	return (block());
+}
+
 // Parse ans return the full ast
 struct ASTnode* parse(const char *name) {
 	Tokens = scan_tokens(name);
-	struct ASTnode* res = statement();
+	char *func_name;
-	struct llist_node *p = Tokens.head;
+	struct ASTnode* res = function(&func_name);
-	while (p != Tokens.tail) {
+
-		free(p->val);
+	free(func_name);
-		p = p->nxt;
+	while (Tokens.length > 0) {
+		token_free(llist_popfront(&Tokens));
 	}
 	llist_free(&Tokens);
 	return (res);

src/print_ast.c

@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "ast.h"
+#include "print_ast.h"
+#include "symbol.h"
+#include "fatals.h"
+#include "util/array.h"
+
+static int tabs;
+
+static void print_tabs(FILE* Outfile) {
+	for (int i = 0; i < tabs; ++i) {
+		fprintf(Outfile, "\t");
+	}
+}
+
+static void ast_dfs(FILE* Outfile, struct ASTnode *x) {
+	print_tabs(Outfile);
+	if (x == NULL) {
+		fprintf(Outfile, "--->NULL.\n");
+		return;
+	}
+
+	switch(x->op) {
+		case A_RETURN: case A_PRINT: {
+			struct ASTunnode *t = x;
+			fprintf(Outfile, "--->UNOP(%s)\n", ast_opname[x->op]);
+			tabs += 1;
+			ast_dfs(Outfile, t->left);
+			tabs -= 1;
+		}	break;
+
+		case A_LIT_I32: {
+			struct ASTi32node *t = x;
+			fprintf(Outfile, "--->INT32(%d)\n", t->val);
+		}	break;
+
+		case A_LIT_I64: {
+			struct ASTi64node *t = x;
+			fprintf(Outfile, "--->INT64(%lld)\n", t->val);
+		}	break;
+
+		case A_BLOCK: {
+			struct ASTblocknode *t = x;
+			fprintf(Outfile, "--->BLOCK(%d statements)\n", t->st.length);
+			tabs += 1;
+			struct llist_node *p = t->st.head;
+			while (p) {
+				ast_dfs(Outfile, p);
+				p = p->nxt;
+			}
+			tabs -= 1;
+		}	break;
+
+		default: {
+			fprintf(Outfile, "--->%s...\n", ast_opname[x->op]);
+		}	break;
+	}
+}
+
+void debug_ast_print(FILE *Outfile, struct ASTnode *rt) {
+	tabs = 0;
+	ast_dfs(Outfile, rt);
+}
+

src/scan.c

@@ -41,7 +41,7 @@ static void skip_whitespaces(void) {
 
 // Scan and return an integer literal value from the input file.
 static void scan_int(struct token *t) {
-	long long res = 0;
+	int64_t res = 0;
 	int c = preview();
 	while ('0' <= c && c <= '9') {
 		res = res * 10 + (c - '0');
@@ -51,12 +51,10 @@ static void scan_int(struct token *t) {
 
 	if (INT32_MIN <= res && res <= INT32_MAX) {
 		t->type = T_I32_LIT;
-		t->val = malloc_or_fail(sizeof(int32_t), __FUNCTION__);
+		t->val_i32 = (int32_t)res;
-		*((int32_t *)t->val) = (int)res;
 	} else {
 		t->type = T_I64_LIT;
-		t->val = malloc_or_fail(sizeof(int64_t), __FUNCTION__);
+		t->val_i64 = (int64_t)res;
-		*((int64_t *)t->val) = res;
 	}
 }
 
@@ -102,6 +100,7 @@ static bool scan_keyword(struct token *t, char *s) {
 		"else",
 		"while",
 		"for",
+		"return",
 		NULL
 	};
 
@@ -114,7 +113,8 @@ static bool scan_keyword(struct token *t, char *s) {
 		T_ELSE,
 		T_WHILE,
 		T_FOR,
-		-1
+		T_RETURN,
+		T_EXCEED,
 	};
 
 	for (int i = 0; map_s[i] != NULL; ++i) {
@@ -139,7 +139,7 @@ static bool scan_1c(struct token *t) {
 		{'(', T_LP},
 		{')', T_RP},
 		{';', T_SEMI},
-		{'\0', -1}
+		{'\0', T_EXCEED}
 	};
 
 	int c = preview();
@@ -156,7 +156,6 @@ static bool scan_1c(struct token *t) {
 // Scan and return the next token found in the input.
 static struct token* scan(void) {
 	struct token *t = malloc_or_fail(sizeof(struct token), __FUNCTION__);
-	t->val = NULL;
 
 	skip_whitespaces();
 	int c = preview();
@@ -203,20 +202,16 @@ static struct token* scan(void) {
 			next();
 		}
 	} else {
-		// If it's a digit, scan the integer literal value in
+		if (isdigit(c)) { // If it's a digit, scan the integer literal value in
-		if (isdigit(c)) {
 			scan_int(t);
 		} else if (isalpha(c) || c == '_') {
-			t->val = scan_indentifier(NULL);
+			t->val_s = scan_indentifier(NULL);
-			if (scan_keyword(t, t->val)) {
+			if (scan_keyword(t, t->val_s)) { // got a keyword
-				// got a keyword
+				free(t->val_s);
-				free(t->val);
+			} else { // not a keyword, so it should be an indentifier.
-				t->val = NULL;
+				t->type = T_ID;
-			} else {
-				// not a keyword, so it should be an indentifier.
-				t->type = T_INDENT;
 			}
-		} else {
+		} else { // cannot match to anything we know, report error.
 			fail_char(c);
 		}
 	}
@@ -242,4 +237,5 @@ struct linklist scan_tokens(const char *name) {
 
 	fclose(Infile);
 	return (res);
-}
+}
+

src/symbol.c

@@ -1,3 +1,4 @@
+/*
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -119,4 +120,4 @@ int addglob(char *s) {
 	trie_set(ss, res);
 	return (res);
 }
-
+*/

src/target.c

@@ -0,0 +1,22 @@
+#include <string.h>
+#include "fatals.h"
+#include "target.h"
+
+int target_parse(const char *target_string) {
+	static const char *target_map_k[] = {
+		"ast",
+		NULL
+	};
+
+	static const int target_map_v[] = {
+		TARGET_AST,
+	};
+
+	for (int i = 0; target_map_k[i]; ++i) {
+		if (strcmp(target_map_k[i], target_string) == 0) {
+			return (target_map_v[i]);
+		}
+	}
+
+	fail_target(target_string);
+}

src/token.c

@@ -1,5 +1,4 @@
 #include <stdlib.h>
-#include <stdio.h>
 #include "token.h"
 
 const char *token_typename[63] = {
@@ -10,20 +9,18 @@ const char *token_typename[63] = {
 	"+", "-", "*", "/",
 	"==", "!=", "<", ">", "<=", ">=",
 	"int", "void", "char", "long",
-	"print", "if", "else", "while", "for",
+	"short",
-	"a signed integer literal (size 32)", "a signed integer literal (size 64)", "an indentifier"
+	"print", "if", "else",
+	"while", "for",
+	"return",
+	"a integer literal (16bit)", "a integer literal (32bit)", "a integer literal (64bit)",
+	"an identifier",
+	NULL
 };
 
 void token_free(struct token *t) {
-	if (t->val) {
+	if (t->type == T_ID && t->val_s) {
-		free(t->val);
+		free(t->val_s);
 	}
 	free(t);
 }
-
-struct token token_make_eof(void) {
-	struct token res;
-	res.type = T_EOF;
-	res.val = NULL;
-	return (res);
-}

src/util/linklist.c

@@ -1,28 +1,21 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdbool.h>
 #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) {
-		fail_malloc(__FUNCTION__);
-	}
-	res->nxt = NULL;
-	res->val = val;
-	return (res);
-}
-
 // Appends an element in the linklist. 
 void llist_pushback(struct linklist *l, void *val) {
+	struct llist_node *x = (struct llist_node*)val;
+	x->nxt = NULL;
 	l->length += 1;
 	if (!l->tail) {
-		l->head = l->tail = llist_createnode(val);
+		l->head = l->tail = val;
 		return;
 	}
-	l->tail->nxt = llist_createnode(val);
+
-	l->tail = l->tail->nxt;
+	l->tail->nxt = x;
+	l->tail = x;
 }
 
 // A variant of pushback
@@ -33,7 +26,7 @@ void llist_pushback_notnull(struct linklist *l, void *val) {
 	}
 }
 
-// Returns the _index_ thh element.
+// Returns the _index_ th element.
 void* llist_get(struct linklist *l, int index) {
 	if (index >= l->length) {
 		fprintf(stderr, "linklist out of range.\n");
@@ -44,21 +37,12 @@ void* llist_get(struct linklist *l, int index) {
 	for (int i = 0; i < index; ++i) {
 		p = p->nxt;
 	}
-	return (p->val);
+	return (p);
 }
 
-// Modify the _index_ thh element.
+// Check if the given linklist is empty
-void llist_set(struct linklist *l, int index, void *val) {
+bool llist_isempty(struct linklist *l) {
-	if (index >= l->length) {
+	return (l->length == 0);
-		fprintf(stderr, "linklist out of range.\n");
-		abort();
-	}
-
-	struct llist_node *p = l->head;
-	for (int i = 0; i < index; ++i) {
-		p = p->nxt;
-	}
-	p->val = val;
 }
 
 // Init a empty linklist.
@@ -68,8 +52,8 @@ void llist_init(struct linklist *l) {
 	l->tail = NULL;
 }
 
-// Frees the linklist.
+// Frees all elements in the link list.
-// Caller must make sure all elements in the linklist has already been freed. 
+// Memory leaks if linklist element is still containing some pointer.
 void llist_free(struct linklist *l) {
 	struct llist_node *p = l->head;
 	struct llist_node *nxt;
@@ -81,22 +65,6 @@ 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) {
@@ -105,8 +73,8 @@ void llist_insert(struct linklist *l, int index, void *val) {
 		return;
 	}
 
+	struct llist_node *x = (struct llist_node*)val;
 	l->length += 1;
-	struct llist_node *x = llist_createnode(val);
 	if (index == 0) {
 		x->nxt = l->head;
 		l->head = x;
@@ -129,16 +97,13 @@ void* llist_popfront(struct linklist *l) {
 	}
 
 	l->length -= 1;
-	void *res = l->head->val;
+	struct llist_node *res = l->head;
+	l->head = res->nxt;
+	res->nxt = NULL;
 	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);
 }
 
@@ -148,11 +113,11 @@ 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) {
@@ -160,7 +125,6 @@ void* llist_remove(struct linklist *l, int index) {
 	}
 	struct llist_node *q = p->nxt;
 	p->nxt = q->nxt;
-	void *res = q->val;
+	q->nxt = NULL;
-	free(q);
+	return (q);
-	return res;
 }

tests/input01

@@ -1,4 +0,0 @@
-{ print 12 * 3;
-  print 18 - 2 * 4;
-  print 1 + 2 + 9 - 5/2 + 3*5;
-}

tests/input01.ans

@@ -1,3 +0,0 @@
-36
-10
-25

tests/input02

@@ -1,7 +0,0 @@
-{
-  int fred;
-  int jim;
-  fred= 5;
-  jim= 12;
-  print fred + jim;
-}

tests/input02.ans

@@ -1 +0,0 @@
-17

tests/input03

@@ -1,8 +0,0 @@
-{
-  int x;
-  x= 1;     print x;
-  x= x + 1; print x;
-  x= x + 1; print x;
-  x= x + 1; print x;
-  x= x + 1; print x;
-}

tests/input03.ans

@@ -1,5 +0,0 @@
-1
-2
-3
-4
-5

tests/input04

@@ -1,12 +0,0 @@
-{
-  int x;
-  x= 7 < 9;  print x;
-  x= 7 <= 9; print x;
-  x= 7 != 9; print x;
-  x= 7 == 7; print x;
-  x= 7 >= 7; print x;
-  x= 7 <= 7; print x;
-  x= 9 > 7;  print x;
-  x= 9 >= 7; print x;
-  x= 9 != 7; print x;
-}

tests/input04.ans

@@ -1,9 +0,0 @@
-1
-1
-1
-1
-1
-1
-1
-1
-1

tests/input05

@@ -1,9 +0,0 @@
-{
-  int i; int j;
-  i=6; j=12;
-  if (i < j) {
-    print i;
-  } else {
-    print j;
-  }
-}

tests/input05.ans

@@ -1 +0,0 @@
-6

tests/input06

@@ -1,7 +0,0 @@
-{ int i;
-  i=1;
-  while (i <= 10) {
-    print i;
-    i= i + 1;
-  }
-}

tests/input06.ans

@@ -1,10 +0,0 @@
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10

tests/input07

@@ -1,6 +0,0 @@
-{
-  int i;
-  for (i= 1; i <= 10; i= i + 1) {
-    print i;
-  }
-}

tests/input07.ans

@@ -1,10 +0,0 @@
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10

tests/input08

@@ -1,6 +0,0 @@
-{
-	long a = 5;
-	long b = a + 5;
-	int c = b - 1;
-	print c;
-}

tests/input08.ans

@@ -1 +0,0 @@
-9

tests/invalid/missing_paren.c

@@ -0,0 +1,3 @@
+int main( {
+    return 0;
+}

tests/invalid/missing_retval.c

@@ -0,0 +1,3 @@
+int main() {
+    return;
+}

tests/invalid/no_brace.c

@@ -0,0 +1,2 @@
+int main() {
+    return 0;

tests/invalid/no_semicolon.c

@@ -0,0 +1,3 @@
+int main() {
+    return 0
+}

tests/invalid/no_space.c

@@ -0,0 +1,3 @@
+int main() {
+    return0;
+}

tests/invalid/wrong_case.c

@@ -0,0 +1,3 @@
+int main() {
+    RETURN 0;
+}

tests/test_llvm.lua

@@ -1,50 +0,0 @@
-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

tests/valid/multi_digit.c

@@ -0,0 +1,3 @@
+int main() {
+    return 100;
+}

tests/valid/newlines.c

@@ -0,0 +1,10 @@
+
+int 
+main
+(   
+)
+{
+return
+0
+;
+}

tests/valid/no_newlines.c

@@ -0,0 +1 @@
+int main(){return 0;}

tests/valid/return_0.c

@@ -0,0 +1,3 @@
+int main() {
+    return 0;
+}

tests/valid/return_2.c

@@ -0,0 +1,3 @@
+int main() {
+    return 2;
+}

tests/valid/spaces.c

@@ -0,0 +1 @@
+   int   main    (  )  {   return  0 ; }