krzosa/smallprojects
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Extract parser and add x64 assembly emission

Browse Source
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
Download Patch File Download Diff File Expand all files Collapse all files

220
parser.c Normal file
View File

@@ -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");
}