Extract parser and add x64 assembly emission

This commit is contained in:
Krzosa Karol
2026-05-13 22:48:57 +02:00
parent 4cffa1f69a
commit f41560c5e7
6 changed files with 339 additions and 274 deletions

2
base.c
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@@ -2,7 +2,7 @@
_Noreturn
void base_panicf(char *file, int line, const char *fmt, ...) {
fprintf(stderr, "%s:%d", file, line);
fprintf(stderr, "%s:%d: ", file, line);
va_list args;
va_start(args, fmt);
vfprintf(stderr, fmt, args);

View File

@@ -1,4 +1,20 @@
set -euo pipefail
# set -euo pipefail
assert_eq() {
expected="$1"
actual="$2"
if [ "$expected" != "$actual" ]; then
echo "assert failed: expected '$expected', got '$actual'"
exit 1
fi
}
verify_expr() {
./main "$1"
clang out.s -o test
./test
assert_eq $? $2
}
if [[ ! -e build ]]; then
mkdir build
@@ -7,4 +23,10 @@ cd build
clang -o meta $(realpath ../meta.c) -g -Wall -Wextra -Wshadow -fdiagnostics-absolute-paths
./meta > ../meta_gen.c
clang -o main $(realpath ../main.c) -g -Wall -Wextra -Wshadow -fdiagnostics-absolute-paths
./main
./main
verify_expr "2+1-1" 2
verify_expr "(2+1-1)*3" 6
echo done

34
emit_asm_x64.c Normal file
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@@ -0,0 +1,34 @@
void emit_expr(FILE *file, Ast *n) {
switch (n->kind) {
case AST_INT: {
fprintf(file, " mov rax, %lu\n", n->u);
} break;
case AST_BINARY: {
emit_expr(file, n->l);
fprintf(file, " push rax\n");
emit_expr(file, n->r);
fprintf(file, " pop rcx\n");
if (n->op == TOK_PLUS) {
fprintf(file, " add rax, rcx\n");
} else if (n->op == TOK_STAR) {
fprintf(file, " imul rax, rcx\n");
} else if (n->op == TOK_MINUS) {
fprintf(file, " mov rdx, rax\n");
fprintf(file, " mov rax, rcx\n");
fprintf(file, " sub rax, rdx\n");
} else {
panicf("error");
}
} break;
default: panicf("error");
}
}
void emit_program(FILE *file, Ast *n) {
fprintf(file, ".intel_syntax noprefix\n");
fprintf(file, ".global main\n");
fprintf(file, "main:\n");
emit_expr(file, n);
fprintf(file, " ret\n");
}

47
lex.c
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@@ -191,4 +191,49 @@ Token_Array lex_file(char *file, char *src, int len) {
}
}
return result;
}
}
void lex_test(void) {
char *src = "12 + 34.5 * 6\n- 7 % 2 / 1 == 1 != 2 <= 3 >= 4 && 3 || 4 << 1 >> 2";
Lexer lex = make_lexer("test.c", src, (int)strlen(src));
assert_token(lex_token(&lex), TOK_INT, "12", 0, 0);
assert_token(lex_token(&lex), TOK_PLUS, "+", 0, 3);
assert_token(lex_token(&lex), TOK_FLOAT, "34.5", 0, 5);
assert_token(lex_token(&lex), TOK_STAR, "*", 0, 10);
assert_token(lex_token(&lex), TOK_INT, "6", 0, 12);
assert_token(lex_token(&lex), TOK_MINUS, "-", 1, 0);
assert_token(lex_token(&lex), TOK_INT, "7", 1, 2);
assert_token(lex_token(&lex), TOK_PERCENT, "%", 1, 4);
assert_token(lex_token(&lex), TOK_INT, "2", 1, 6);
assert_token(lex_token(&lex), TOK_SLASH, "/", 1, 8);
assert_token(lex_token(&lex), TOK_INT, "1", 1, 10);
assert_token(lex_token(&lex), TOK_EQ, "==", 1, 12);
assert_token(lex_token(&lex), TOK_INT, "1", 1, 15);
assert_token(lex_token(&lex), TOK_NEQ, "!=", 1, 17);
assert_token(lex_token(&lex), TOK_INT, "2", 1, 20);
assert_token(lex_token(&lex), TOK_LEQ, "<=", 1, 22);
assert_token(lex_token(&lex), TOK_INT, "3", 1, 25);
assert_token(lex_token(&lex), TOK_GEQ, ">=", 1, 27);
assert_token(lex_token(&lex), TOK_INT, "4", 1, 30);
assert_token(lex_token(&lex), TOK_AND, "&&", 1, 32);
assert_token(lex_token(&lex), TOK_INT, "3", 1, 35);
assert_token(lex_token(&lex), TOK_OR, "||", 1, 37);
assert_token(lex_token(&lex), TOK_INT, "4", 1, 40);
assert_token(lex_token(&lex), TOK_LSHIFT, "<<", 1, 42);
assert_token(lex_token(&lex), TOK_INT, "1", 1, 45);
assert_token(lex_token(&lex), TOK_RSHIFT, ">>", 1, 47);
assert_token(lex_token(&lex), TOK_INT, "2", 1, 50);
Token eof = lex_token(&lex);
assert(eof.kind == TOK_EOF);
assert(eof.len == 0);
assert(eof.line == 1);
assert(eof.column == 51);
Token_Array array = lex_file("test.c", src, (int)strlen(src));
assert(array.len == 28);
printf("lexer tests passed\n");
}

284
main.c
View File

@@ -9,277 +9,21 @@
#include "base.c"
#include "meta_gen.c"
#include "lex.c"
#include "parser.c"
#include "emit_asm_x64.c"
typedef struct Parser {
Token *at;
Token *end;
} Parser;
typedef enum Ast_Kind {
AST_NONE,
AST_ERROR,
AST_INT,
AST_UNARY,
AST_BINARY,
} Ast_Kind;
typedef struct Ast Ast;
struct Ast {
Ast_Kind kind;
Token *pos;
union {
uint64_t u;
struct {
Token_Kind op;
Ast *l;
Ast *r;
};
char *error;
};
};
Token *next_token(Parser *p) {
if (p->at < p->end) {
return p->at++;
}
return p->at;
}
Token *match_token(Parser *p, Token_Kind kind) {
if (p->at->kind == kind) {
return next_token(p);
}
return NULL;
}
Token *expect_token(Parser *p, Token_Kind kind) {
if (p->at->kind == kind) {
return next_token(p);
}
panicf("expected token kind: %s, got instead: %s", token_to_name(p->at->kind), token_to_name(kind));
}
Ast *create_ast(Token *token, Ast_Kind kind) {
Ast *result = calloc(1, sizeof(Ast));
result->pos = token;
result->kind = kind;
return result;
}
Ast *create_binary_expr(Token *token, Token_Kind op, Ast *left, Ast *right) {
Ast *result = create_ast(token, AST_BINARY);
result->op = op;
result->l = left;
result->r = right;
return result;
}
Ast *parse_expr(Parser *p, int power_of_binding_to_right);
Ast *parse_atom(Parser *p) {
Token *token = p->at;
Ast *n = NULL;
if (match_token(p, TOK_INT)) {
n = create_ast(token, AST_INT);
n->u = token->u;
} else if (match_token(p, TOK_LPAREN)) {
// @todo: do a comma list here
n = parse_expr(p, 0);
expect_token(p, TOK_RPAREN);
int main(int argc, char **argv) {
if (argc == 2) {
Token_Array tokens = lex_file("expr", argv[1], strlen(argv[1]));
Parser parser = {tokens.data, tokens.data + tokens.len};
Ast *ast = parse_expr(&parser, 0);
FILE *file = fopen("out.s", "w");
emit_program(file, ast);
fclose(file);
} else {
panicf("unknown token in %s. %.*s (%s/%d), ", __FUNCTION__, token->len, token->str, token_to_name(token->kind), token->kind);
vec_test();
lex_test();
parser_test();
}
return n;
}
int get_binding_power(Token *tok) {
switch (tok->kind) {
case TOK_STAR: case TOK_SLASH: case TOK_PERCENT: return 120;
case TOK_PLUS: case TOK_MINUS: return 110;
case TOK_LSHIFT: case TOK_RSHIFT: return 100;
case TOK_LT: case TOK_LEQ: case TOK_GT: case TOK_GEQ: return 90;
case TOK_EQ: case TOK_NEQ: return 80;
case TOK_BITAND: return 70;
case TOK_BITXOR: return 60;
case TOK_BITOR: return 50;
case TOK_AND: return 40;
case TOK_OR: return 30;
default: return 0;
}
}
Ast *parse_valid_left_binding(Parser *p, Token *tok, Ast *left) {
switch (tok->kind) {
case TOK_PLUS: case TOK_MINUS: case TOK_STAR: case TOK_SLASH: case TOK_PERCENT:
case TOK_EQ: case TOK_NEQ: case TOK_LT: case TOK_LEQ: case TOK_GT: case TOK_GEQ: case TOK_BITAND:
case TOK_BITOR: case TOK_BITXOR: case TOK_AND: case TOK_OR: case TOK_LSHIFT: case TOK_RSHIFT: {
return create_binary_expr(tok, tok->kind, left, parse_expr(p, get_binding_power(tok)));
} break;
default: panicf("unknown token in %s. %.*s (%s/%d), ", __FUNCTION__, tok->len, tok->str, token_to_name(tok->kind), tok->kind);
}
return NULL;
}
Ast *parse_expr(Parser *p, int power_of_binding_to_right) {
Ast *n = parse_atom(p);
while (get_binding_power(p->at) > power_of_binding_to_right) {
Token *tok = next_token(p);
n = parse_valid_left_binding(p, tok, n);
}
return n;
}
int64_t eval_expr(Ast *n) {
switch (n->kind) {
case AST_INT: return (int64_t)n->u;
case AST_BINARY: {
int64_t left = eval_expr(n->l);
int64_t right = eval_expr(n->r);
switch (n->op) {
case TOK_PLUS: return left + right;
case TOK_MINUS: return left - right;
case TOK_STAR: return left * right;
case TOK_SLASH: return left / right;
case TOK_PERCENT: return left % right;
case TOK_EQ: return left == right;
case TOK_NEQ: return left != right;
case TOK_LT: return left < right;
case TOK_LEQ: return left <= right;
case TOK_GT: return left > right;
case TOK_GEQ: return left >= right;
case TOK_BITAND: return left & right;
case TOK_BITOR: return left | right;
case TOK_BITXOR: return left ^ right;
case TOK_AND: return left && right;
case TOK_OR: return left || right;
case TOK_LSHIFT: return left << right;
case TOK_RSHIFT: return left >> right;
default: panicf("invalid token kind in eval_expr, binary");
}
} break;
default: panicf("invalid ast kind in eval_expr");
}
}
void print_expr(Ast *n) {
switch (n->kind) {
case AST_INT: printf("%lu", n->u); break;
case AST_BINARY: {
print_expr(n->l);
printf(" %s ", token_to_op(n->op));
print_expr(n->r);
} break;
default: panicf("encountered invalid ast kind in %s of kind: %d\n", __FUNCTION__, n->kind);
}
}
void parser_test(void) {
#define TEST_EVAL(expr) do { \
Token_Array tokens = lex_file("eval_test", (#expr), strlen((#expr)));\
Parser p = {tokens.data, tokens.data + tokens.len};\
Ast *result = parse_expr(&p, 0);\
int64_t left = eval_expr(result);\
int64_t right = (expr);\
if (left != right) {\
printf("%s:%d expected: %ld, got: %ld\n expression: ", __FILE__, __LINE__, left, right);\
print_expr(result);\
printf("\n");\
}\
} while (0)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wparentheses"
TEST_EVAL(32+5-4);
TEST_EVAL(16/2/2);
TEST_EVAL(9*4/6);
TEST_EVAL(17%5);
TEST_EVAL(5125-42|(4&3)^2|2%1242);
TEST_EVAL((45%2)^(23&3));
TEST_EVAL(1<16*2);
TEST_EVAL(16>1+2);
TEST_EVAL(4<=2+2);
TEST_EVAL(5>=2+2);
TEST_EVAL(4==2+2);
TEST_EVAL(5!=2+2);
TEST_EVAL(1+1+1+1+2-2-3-4-5);
TEST_EVAL(5%2^5&6|3);
TEST_EVAL(6&3);
TEST_EVAL(6|3);
TEST_EVAL(6^3);
TEST_EVAL(1&&2);
TEST_EVAL(0||3);
TEST_EVAL(1||0&&0);
TEST_EVAL(8<<2);
TEST_EVAL(32>>3);
TEST_EVAL((2+3)*(4+5));
TEST_EVAL(9>3&1);
TEST_EVAL(8|1<4);
TEST_EVAL(7<=3+4);
TEST_EVAL(8>=2*4);
TEST_EVAL(4==2+2);
TEST_EVAL(5!=2+2);
TEST_EVAL(1&&2);
TEST_EVAL(0||3);
TEST_EVAL(1||0&&0);
TEST_EVAL(8<<2);
TEST_EVAL(32>>3);
TEST_EVAL(1+2<<3);
TEST_EVAL(16>>1+1);
#pragma clang diagnostic pop
printf("parser tests passed\n");
}
void lex_test(void) {
char *src = "12 + 34.5 * 6\n- 7 % 2 / 1 == 1 != 2 <= 3 >= 4 && 3 || 4 << 1 >> 2";
Lexer lex = make_lexer("test.c", src, (int)strlen(src));
assert_token(lex_token(&lex), TOK_INT, "12", 0, 0);
assert_token(lex_token(&lex), TOK_PLUS, "+", 0, 3);
assert_token(lex_token(&lex), TOK_FLOAT, "34.5", 0, 5);
assert_token(lex_token(&lex), TOK_STAR, "*", 0, 10);
assert_token(lex_token(&lex), TOK_INT, "6", 0, 12);
assert_token(lex_token(&lex), TOK_MINUS, "-", 1, 0);
assert_token(lex_token(&lex), TOK_INT, "7", 1, 2);
assert_token(lex_token(&lex), TOK_PERCENT, "%", 1, 4);
assert_token(lex_token(&lex), TOK_INT, "2", 1, 6);
assert_token(lex_token(&lex), TOK_SLASH, "/", 1, 8);
assert_token(lex_token(&lex), TOK_INT, "1", 1, 10);
assert_token(lex_token(&lex), TOK_EQ, "==", 1, 12);
assert_token(lex_token(&lex), TOK_INT, "1", 1, 15);
assert_token(lex_token(&lex), TOK_NEQ, "!=", 1, 17);
assert_token(lex_token(&lex), TOK_INT, "2", 1, 20);
assert_token(lex_token(&lex), TOK_LEQ, "<=", 1, 22);
assert_token(lex_token(&lex), TOK_INT, "3", 1, 25);
assert_token(lex_token(&lex), TOK_GEQ, ">=", 1, 27);
assert_token(lex_token(&lex), TOK_INT, "4", 1, 30);
assert_token(lex_token(&lex), TOK_AND, "&&", 1, 32);
assert_token(lex_token(&lex), TOK_INT, "3", 1, 35);
assert_token(lex_token(&lex), TOK_OR, "||", 1, 37);
assert_token(lex_token(&lex), TOK_INT, "4", 1, 40);
assert_token(lex_token(&lex), TOK_LSHIFT, "<<", 1, 42);
assert_token(lex_token(&lex), TOK_INT, "1", 1, 45);
assert_token(lex_token(&lex), TOK_RSHIFT, ">>", 1, 47);
assert_token(lex_token(&lex), TOK_INT, "2", 1, 50);
Token eof = lex_token(&lex);
assert(eof.kind == TOK_EOF);
assert(eof.len == 0);
assert(eof.line == 1);
assert(eof.column == 51);
Token_Array array = lex_file("test.c", src, (int)strlen(src));
assert(array.len == 28);
printf("lexer tests passed\n");
}
int main() {
vec_test();
lex_test();
parser_test();
}

220
parser.c Normal file
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@@ -0,0 +1,220 @@
typedef struct Parser {
Token *at;
Token *end;
} Parser;
typedef enum Ast_Kind {
AST_NONE,
AST_ERROR,
AST_INT,
AST_UNARY,
AST_BINARY,
} Ast_Kind;
typedef struct Ast Ast;
struct Ast {
Ast_Kind kind;
Token *pos;
union {
uint64_t u;
struct {
Token_Kind op;
Ast *l;
Ast *r;
};
char *error;
};
};
Token *next_token(Parser *p) {
if (p->at < p->end) {
return p->at++;
}
return p->at;
}
Token *match_token(Parser *p, Token_Kind kind) {
if (p->at->kind == kind) {
return next_token(p);
}
return NULL;
}
Token *expect_token(Parser *p, Token_Kind kind) {
if (p->at->kind == kind) {
return next_token(p);
}
panicf("expected token kind: %s, got instead: %s", token_to_name(p->at->kind), token_to_name(kind));
}
Ast *create_ast(Token *token, Ast_Kind kind) {
Ast *result = calloc(1, sizeof(Ast));
result->pos = token;
result->kind = kind;
return result;
}
Ast *create_binary_expr(Token *token, Token_Kind op, Ast *left, Ast *right) {
Ast *result = create_ast(token, AST_BINARY);
result->op = op;
result->l = left;
result->r = right;
return result;
}
Ast *parse_expr(Parser *p, int power_of_binding_to_right);
Ast *parse_atom(Parser *p) {
Token *token = p->at;
Ast *n = NULL;
if (match_token(p, TOK_INT)) {
n = create_ast(token, AST_INT);
n->u = token->u;
} else if (match_token(p, TOK_LPAREN)) {
// @todo: do a comma list here
n = parse_expr(p, 0);
expect_token(p, TOK_RPAREN);
} else {
panicf("unknown token in %s. %.*s (%s/%d), ", __FUNCTION__, token->len, token->str, token_to_name(token->kind), token->kind);
}
return n;
}
int get_binding_power(Token *tok) {
switch (tok->kind) {
case TOK_STAR: case TOK_SLASH: case TOK_PERCENT: return 120;
case TOK_PLUS: case TOK_MINUS: return 110;
case TOK_LSHIFT: case TOK_RSHIFT: return 100;
case TOK_LT: case TOK_LEQ: case TOK_GT: case TOK_GEQ: return 90;
case TOK_EQ: case TOK_NEQ: return 80;
case TOK_BITAND: return 70;
case TOK_BITXOR: return 60;
case TOK_BITOR: return 50;
case TOK_AND: return 40;
case TOK_OR: return 30;
default: return 0;
}
}
Ast *parse_valid_left_binding(Parser *p, Token *tok, Ast *left) {
switch (tok->kind) {
case TOK_PLUS: case TOK_MINUS: case TOK_STAR: case TOK_SLASH: case TOK_PERCENT:
case TOK_EQ: case TOK_NEQ: case TOK_LT: case TOK_LEQ: case TOK_GT: case TOK_GEQ: case TOK_BITAND:
case TOK_BITOR: case TOK_BITXOR: case TOK_AND: case TOK_OR: case TOK_LSHIFT: case TOK_RSHIFT: {
return create_binary_expr(tok, tok->kind, left, parse_expr(p, get_binding_power(tok)));
} break;
default: panicf("unknown token in %s. %.*s (%s/%d), ", __FUNCTION__, tok->len, tok->str, token_to_name(tok->kind), tok->kind);
}
return NULL;
}
Ast *parse_expr(Parser *p, int power_of_binding_to_right) {
Ast *n = parse_atom(p);
while (get_binding_power(p->at) > power_of_binding_to_right) {
Token *tok = next_token(p);
n = parse_valid_left_binding(p, tok, n);
}
return n;
}
int64_t eval_expr(Ast *n) {
switch (n->kind) {
case AST_INT: return (int64_t)n->u;
case AST_BINARY: {
int64_t left = eval_expr(n->l);
int64_t right = eval_expr(n->r);
switch (n->op) {
case TOK_PLUS: return left + right;
case TOK_MINUS: return left - right;
case TOK_STAR: return left * right;
case TOK_SLASH: return left / right;
case TOK_PERCENT: return left % right;
case TOK_EQ: return left == right;
case TOK_NEQ: return left != right;
case TOK_LT: return left < right;
case TOK_LEQ: return left <= right;
case TOK_GT: return left > right;
case TOK_GEQ: return left >= right;
case TOK_BITAND: return left & right;
case TOK_BITOR: return left | right;
case TOK_BITXOR: return left ^ right;
case TOK_AND: return left && right;
case TOK_OR: return left || right;
case TOK_LSHIFT: return left << right;
case TOK_RSHIFT: return left >> right;
default: panicf("invalid token kind in eval_expr, binary");
}
} break;
default: panicf("invalid ast kind in eval_expr");
}
}
void print_expr(Ast *n) {
switch (n->kind) {
case AST_INT: printf("%lu", n->u); break;
case AST_BINARY: {
print_expr(n->l);
printf(" %s ", token_to_op(n->op));
print_expr(n->r);
} break;
default: panicf("encountered invalid ast kind in %s of kind: %d\n", __FUNCTION__, n->kind);
}
}
void parser_test(void) {
#define TEST_EVAL(expr) do { \
Token_Array tokens = lex_file("eval_test", (#expr), strlen((#expr)));\
Parser p = {tokens.data, tokens.data + tokens.len};\
Ast *result = parse_expr(&p, 0);\
int64_t left = eval_expr(result);\
int64_t right = (expr);\
if (left != right) {\
printf("%s:%d expected: %ld, got: %ld\n expression: ", __FILE__, __LINE__, left, right);\
print_expr(result);\
printf("\n");\
}\
} while (0)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wparentheses"
TEST_EVAL(32+5-4);
TEST_EVAL(16/2/2);
TEST_EVAL(9*4/6);
TEST_EVAL(17%5);
TEST_EVAL(5125-42|(4&3)^2|2%1242);
TEST_EVAL((45%2)^(23&3));
TEST_EVAL(1<16*2);
TEST_EVAL(16>1+2);
TEST_EVAL(4<=2+2);
TEST_EVAL(5>=2+2);
TEST_EVAL(4==2+2);
TEST_EVAL(5!=2+2);
TEST_EVAL(1+1+1+1+2-2-3-4-5);
TEST_EVAL(5%2^5&6|3);
TEST_EVAL(6&3);
TEST_EVAL(6|3);
TEST_EVAL(6^3);
TEST_EVAL(1&&2);
TEST_EVAL(0||3);
TEST_EVAL(1||0&&0);
TEST_EVAL(8<<2);
TEST_EVAL(32>>3);
TEST_EVAL((2+3)*(4+5));
TEST_EVAL(9>3&1);
TEST_EVAL(8|1<4);
TEST_EVAL(7<=3+4);
TEST_EVAL(8>=2*4);
TEST_EVAL(4==2+2);
TEST_EVAL(5!=2+2);
TEST_EVAL(1&&2);
TEST_EVAL(0||3);
TEST_EVAL(1||0&&0);
TEST_EVAL(8<<2);
TEST_EVAL(32>>3);
TEST_EVAL(1+2<<3);
TEST_EVAL(16>>1+1);
#pragma clang diagnostic pop
printf("parser tests passed\n");
}