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parser.c
887 lines (675 loc) · 22.2 KB
/
parser.c
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#include <stdlib.h>
#include <stdio.h> // TODO: remove
#include <assert.h>
#include "parser.h"
#include "vector.h"
#include "token.h"
#include "log.h"
#define ErrRet \
rewind_state(parser, _parser_state); \
return res;
#define ErrProp \
if (res.result == PARSER_ERROR) {ErrRet}
static ParserResult parse_transition_unit(Parser *parser);
static ParserResult parse_external_declaration(Parser *parser);
static ParserResult parse_function_definition(Parser *parser);
static ParserResult parse_declaration_specifiers(Parser *parser);
static ParserResult parse_declarator(Parser *parser);
static ParserResult parse_direct_declarator(Parser *parser);
static ParserResult parse_parameter_type_list(Parser *parser);
static ParserResult parse_parameter_list(Parser *parser);
static ParserResult parse_parameter_declaration(Parser *parser);
static ParserResult parse_stmt(Parser *parser);
static ParserResult parse_stmt_compound(Parser *parser);
static ParserResult parse_block_item(Parser *parser);
static ParserResult parse_stmt_expr(Parser *parser);
static ParserResult parse_stmt_selection(Parser *parser);
static ParserResult parse_stmt_jump(Parser *parser);
static ParserResult parse_expr(Parser *parser);
static ParserResult parse_expr_assign(Parser *parser);
static ParserResult parse_expr_additive(Parser *parser);
static ParserResult parse_expr_postfix(Parser *parser);
static ParserResult parse_argument_expr_list(Parser *parser);
static ParserResult parse_expr_primary(Parser *parser);
static ParserResult parse_constant(Parser *parser);
static ParserResult parse_id(Parser *parser);
static ParserResult combinator_more1(Parser *parser, ParserResult (*f)(Parser *parser));
static ParserResult combinator_more1_sep(Parser *parser, TokenKind sep, ParserResult (*f)(Parser *parser));
static ParserResult current_token(Parser *parser);
static ParserResult assume_token(Parser *parser, TokenKind kind);
static void forward_token(Parser *parser);
static void debug_print_current_token(Parser *parser);
typedef size_t state_t;
static state_t save_state(Parser *parser);
static void rewind_state(Parser *parser, state_t state);
struct parser_t {
Vector* tokens;
NodeArena* arena;
size_t position;
Vector* position_stack;
};
Parser* parser_new(Vector* tokens, NodeArena* arena) {
Parser* p = (Parser*)malloc(sizeof(Parser));
if (!p) {
return 0;
}
p->tokens = tokens;
p->arena = arena;
p->position = 0;
p->position_stack = vector_new(sizeof(size_t));
return p;
}
void parser_drop(Parser *parser) {
if (!parser) {
return;
}
vector_drop(parser->position_stack);
free(parser);
}
ParserResult parser_parse(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = parse_transition_unit(parser); ErrProp;
return res;
}
void parser_fprint_error(FILE *fp, ParseError *err) {
switch (err->kind) {
case PARSER_ERROR_KIND_EOF:
fprintf(fp, "Unexpected EOF");
break;
case PARSER_ERROR_KIND_UNEXPECTED:
fprintf(fp, "Unexpected token: ");
token_fprint(fp, err->value.unexpected.token);
break;
case PARSER_ERROR_KIND_MORE1:
fprintf(fp, "Eexpected more than 0 tokens");
break;
}
}
ParserResult parse_transition_unit(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = combinator_more1(parser, parse_external_declaration); ErrProp;
Vector* nodes = res.value.nodes;
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_TRANS_UNIT;
node->value.trans_unit.decls = nodes;
res.value.node = node;
return res;
}
ParserResult parse_external_declaration(Parser *parser) {
return parse_function_definition(parser);
}
ParserResult parse_function_definition(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = parse_id(parser); ErrProp; // TODO: fix
Node* decl_spec = res.value.node;
res = parse_declarator(parser); ErrProp;
Node* decl = res.value.node;
res = parse_stmt_compound(parser); ErrProp;
Node* block = res.value.node;
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_FUNC_DEF;
node->value.func_def.decl_spec = decl_spec;
node->value.func_def.decl = decl;
node->value.func_def.block = block;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
ParserResult parse_declaration_specifiers(Parser *parser) {
return parse_id(parser); // TODO: fix
}
ParserResult parse_declarator(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = parse_direct_declarator(parser); ErrProp;
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_DECLARATOR;
node->value.declarator.node = res.value.node;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
ParserResult parse_direct_declarator(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
Node* gen_node;
res = parse_id(parser);
if (res.result == PARSER_ERROR) {
goto phase2;
}
{
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_DIRECT_DECLARATOR;
node->value.direct_declarator.base = res.value.node;
node->value.direct_declarator.kind = NODE_DIRECT_DECLARATOR_KIND_BASE;
gen_node = node;
}
goto base_passed;
phase2:
res = assume_token(parser, TOK_KIND_LPAREN); ErrProp;
forward_token(parser);
res = parse_declarator(parser); ErrProp;
Node* decl = res.value.node;
res = assume_token(parser, TOK_KIND_RPAREN); ErrProp;
forward_token(parser);
{
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_DIRECT_DECLARATOR;
node->value.direct_declarator.base = decl;
node->value.direct_declarator.kind = NODE_DIRECT_DECLARATOR_KIND_BASE;
gen_node = node;
}
base_passed:
for(;;) {
_parser_state = save_state(parser);
res = current_token(parser);
if (res.result == PARSER_ERROR) {
rewind_state(parser, _parser_state);
goto total_passed;
}
forward_token(parser);
NodeDirectDeclaratorKind d;
Node* nodes[2] = {NULL, NULL};
switch(res.value.token->kind) {
case TOK_KIND_LPAREN:
res = parse_parameter_type_list(parser);
if (res.result == PARSER_OK) {
d = NODE_DIRECT_DECLARATOR_KIND_PARAM_TYPE_LIST;
nodes[0] = res.value.node;
goto partial_paren_passed;
}
goto total_passed; // Not matched
partial_paren_passed:
res = assume_token(parser, TOK_KIND_RPAREN);
if (res.result == PARSER_ERROR) {
goto total_passed;
}
forward_token(parser);
break;
case TOK_KIND_LBRACKET:
res = assume_token(parser, TOK_KIND_RBRACKET);
if (res.result == PARSER_ERROR) {
goto total_passed;
}
forward_token(parser);
break;
default:
goto total_passed;
}
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_DIRECT_DECLARATOR;
node->value.direct_declarator.kind = d;
node->value.direct_declarator.base = gen_node;
switch(d) {
case NODE_DIRECT_DECLARATOR_KIND_PARAM_TYPE_LIST:
node->value.direct_declarator.args[0] = nodes[0];
break;
default:
assert(0); // TODO: error handling...
}
gen_node = node;
}
total_passed:
rewind_state(parser, _parser_state);
res.result = PARSER_OK;
res.value.node = gen_node;
return res;
}
// TODO: support '...'
ParserResult parse_parameter_type_list(Parser *parser) {
return parse_parameter_list(parser);
}
ParserResult parse_parameter_list(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = combinator_more1_sep(parser, TOK_KIND_COMMA, parse_parameter_declaration); ErrProp;
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_PARAM_LIST;
node->value.param_list.params = res.value.nodes;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
ParserResult parse_parameter_declaration(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = parse_declaration_specifiers(parser); ErrProp;
Node* spec = res.value.node;
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_PARAM_DECL;
node->value.param_decl.spec = spec;
res = parse_declarator(parser);
if (res.result == PARSER_ERROR) {
goto next_phase;
}
node->value.param_decl.decl = res.value.node;
res.result = PARSER_OK;
res.value.node = node;
return res;
next_phase:
// TODO: support 'abstract-declarator opt'
node->value.param_decl.decl = NULL;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
ParserResult parse_stmt(Parser *parser) {
ParserResult res;
res = parse_stmt_compound(parser);
if (res.result == PARSER_OK) {
goto finish;
}
res = parse_stmt_expr(parser);
if (res.result == PARSER_OK) {
goto finish;
}
res = parse_stmt_selection(parser);
if (res.result == PARSER_OK) {
goto finish;
}
res = parse_stmt_jump(parser);
if (res.result == PARSER_OK) {
goto finish;
}
// Not matched...
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_UNEXPECTED; // TODO: fix
fprintf(DEBUGOUT, "failed: parse stmt\n");
finish:
return res;
}
ParserResult parse_stmt_compound(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = assume_token(parser, TOK_KIND_LBRACE); ErrProp;
forward_token(parser);
res = combinator_more1(parser, parse_block_item); ErrProp;
Vector* nodes = res.value.nodes;
res = assume_token(parser, TOK_KIND_RBRACE); ErrProp;
forward_token(parser);
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_STMT_COMPOUND;
node->value.stmt_compound.stmts = nodes;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
ParserResult parse_block_item(Parser *parser) {
ParserResult res;
res = parse_stmt(parser);
if (res.result == PARSER_OK) {
goto finish;
}
// Not matched...
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_UNEXPECTED; // TODO: fix
finish:
return res;
}
ParserResult parse_stmt_expr(Parser *parser) {
fprintf(DEBUGOUT, "parse_stmt_expr: START!\n");
ParserResult res;
state_t _parser_state = save_state(parser);
Node* expr = NULL;
res = parse_expr(parser); // Optional
if (res.result == PARSER_OK) {
fprintf(DEBUGOUT, "parse_stmt_expr: EXPR OK!\n");
expr = res.value.node;
}
fprintf(DEBUGOUT, "parse_stmt_expr: EXPR!\n");
debug_print_current_token(parser);
res = assume_token(parser, TOK_KIND_SEMICOLON); ErrProp;
forward_token(parser);
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_STMT_EXPR;
node->value.stmt_expr.expr = expr;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
ParserResult parse_stmt_selection(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
fprintf(DEBUGOUT, "parse_stmt_selection: START!\n");
res = current_token(parser); ErrProp;
forward_token(parser);
Token* t = res.value.token;
switch (t->kind) {
case TOK_KIND_IF:
res = assume_token(parser, TOK_KIND_LPAREN); ErrProp;
forward_token(parser);
res = parse_expr(parser); ErrProp;
Node* cond_expr = res.value.node;
res = assume_token(parser, TOK_KIND_RPAREN); ErrProp;
forward_token(parser);
res = parse_stmt(parser); ErrProp;
Node* then_body = res.value.node;
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_STMT_IF;
node->value.stmt_if.cond = cond_expr;
node->value.stmt_if.then_b = then_body;
node->value.stmt_if.else_b = NULL;
_parser_state = save_state(parser);
// Next, Check else clause
res = assume_token(parser, TOK_KIND_ELSE);
if (res.result == PARSER_ERROR) {
goto if_passed;
}
forward_token(parser);
res = parse_stmt(parser);
if (res.result == PARSER_ERROR) {
goto if_passed;
}
node->value.stmt_if.else_b = res.value.node;
_parser_state = save_state(parser);
if_passed:
rewind_state(parser, _parser_state);
res.result = PARSER_OK;
res.value.node = node;
return res;
default:
// TODO: support switch
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_UNEXPECTED;
res.error.value.unexpected.token = t;
rewind_state(parser, _parser_state);
return res;
}
}
ParserResult parse_stmt_jump(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = current_token(parser); ErrProp;
forward_token(parser);
Token* t = res.value.token;
switch (t->kind) {
case TOK_KIND_RETURN:
res = parse_expr(parser); ErrProp;
Node* expr = res.value.node;
res = assume_token(parser, TOK_KIND_SEMICOLON); ErrProp;
forward_token(parser);
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_STMT_JUMP;
node->value.stmt_jump.kind = t->kind;
node->value.stmt_jump.expr = expr;
res.result = PARSER_OK;
res.value.node = node;
return res;
default:
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_UNEXPECTED;
res.error.value.unexpected.token = t;
rewind_state(parser, _parser_state);
return res;
}
}
ParserResult parse_expr(Parser *parser) {
return parse_expr_assign(parser);
}
ParserResult parse_expr_assign(Parser *parser) {
return parse_expr_additive(parser);
}
ParserResult parse_expr_additive(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = parse_expr_postfix(parser); ErrProp;
for (;;) {
_parser_state = save_state(parser);
ParserResult res0 = current_token(parser);
if (res0.result == PARSER_ERROR) {
rewind_state(parser, _parser_state);
goto escape;
}
Token* op = res0.value.token;
switch (op->kind) {
case TOK_KIND_PLUS:
break;
case TOK_KIND_MINUS:
break;
default:
rewind_state(parser, _parser_state);
goto escape;
}
forward_token(parser);
res0 = parse_expr_postfix(parser);
if (res0.result == PARSER_ERROR) {
rewind_state(parser, _parser_state);
goto escape;
}
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_EXPR_BIN;
node->value.expr_bin.op = op;
node->value.expr_bin.lhs = res.value.node;
node->value.expr_bin.rhs = res0.value.node;
res.value.node = node;
_parser_state = save_state(parser); // Forward state
}
escape:
return res;
}
ParserResult parse_expr_postfix(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
Node* gen_node;
res = parse_expr_primary(parser); ErrProp;
gen_node = res.value.node;
for(;;) {
_parser_state = save_state(parser);
res = current_token(parser);
if (res.result == PARSER_ERROR) {
rewind_state(parser, _parser_state);
goto total_passed;
}
forward_token(parser);
NodeExprPostfixKind d;
Node* nodes[1] = {NULL};
switch(res.value.token->kind) {
case TOK_KIND_LPAREN:
res = parse_argument_expr_list(parser); // Optional
d = NODE_EXPR_POSTFIX_KIND_FUNC_CALL;
nodes[0] = NULL;
if (res.result == PARSER_OK) {
nodes[0] = res.value.node;
}
res = assume_token(parser, TOK_KIND_RPAREN);
if (res.result == PARSER_ERROR) {
goto total_passed;
}
forward_token(parser);
break;
case TOK_KIND_LBRACKET:
res = assume_token(parser, TOK_KIND_RBRACKET);
if (res.result == PARSER_ERROR) {
goto total_passed;
}
forward_token(parser);
break;
default:
goto total_passed;
}
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_EXPR_POSTFIX;
node->value.expr_postfix.kind = d;
node->value.expr_postfix.lhs = gen_node;
switch(d) {
case NODE_EXPR_POSTFIX_KIND_FUNC_CALL:
node->value.expr_postfix.rhs = nodes[0]; // Nullable
break;
default:
assert(0); // TODO: error handling...
}
gen_node = node;
}
total_passed:
rewind_state(parser, _parser_state);
res.result = PARSER_OK;
res.value.node = gen_node;
return res;
}
ParserResult parse_argument_expr_list(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = combinator_more1_sep(parser, TOK_KIND_COMMA, parse_expr_assign); ErrProp;
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_ARGS_LIST;
node->value.args_list.args = res.value.nodes;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
ParserResult parse_expr_primary(Parser *parser) {
ParserResult res;
res = parse_id(parser);
if (res.result == PARSER_OK) {
goto finish;
}
res = parse_constant(parser);
if (res.result == PARSER_OK) {
goto finish;
}
// Not matched...
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_UNEXPECTED; // TODO: fix
finish:
return res;
}
ParserResult parse_constant(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = current_token(parser); ErrProp;
forward_token(parser);
Token* t = res.value.token;
switch (t->kind) {
case TOK_KIND_INT_LIT:
{
char* const tok_buf = token_to_string(t);
long int n = strtol(tok_buf, NULL, 10); // TODO: fix type
free(tok_buf);
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_LIT_INT;
node->value.lit_int.v = n;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
case TOK_KIND_STRING_LIT:
{
char* const tok_buf = token_to_string(t);
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_LIT_STRING;
node->value.lit_string.v = tok_buf;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
default:
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_UNEXPECTED;
res.error.value.unexpected.token = t;
rewind_state(parser, _parser_state);
return res;
}
}
ParserResult parse_id(Parser *parser) {
ParserResult res;
state_t _parser_state = save_state(parser);
res = current_token(parser); ErrProp;
forward_token(parser);
debug_print_current_token(parser);
Token* t = res.value.token;
switch (t->kind) {
case TOK_KIND_ID:
{
Node* node = node_arena_malloc(parser->arena);
node->kind = NODE_ID;
node->value.id.tok = t;
res.result = PARSER_OK;
res.value.node = node;
return res;
}
default:
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_UNEXPECTED;
res.error.value.unexpected.token = t;
rewind_state(parser, _parser_state);
return res;
}
}
ParserResult combinator_more1(Parser *parser, ParserResult (*f)(Parser *parser)) {
return combinator_more1_sep(parser, TOK_KIND_EMPTY, f);
}
// TODO: Use sep
ParserResult combinator_more1_sep(Parser *parser, TokenKind sep, ParserResult (*f)(Parser *parser)) {
ParserResult res;
state_t _parser_state = save_state(parser);
Vector* elems = vector_new(sizeof(Node*));
for(;;) {
res = f(parser);
if (res.result == PARSER_ERROR) {
break;
}
Node** np = (Node**)vector_append(elems);
*np = res.value.node;
}
if (vector_len(elems) == 0) {
vector_drop(elems);
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_MORE1;
rewind_state(parser, _parser_state);
return res;
}
res.result = PARSER_OK;
res.value.nodes = elems;
return res;
}
ParserResult current_token(Parser *parser) {
ParserResult res;
Token* t = (Token*)vector_at(parser->tokens, parser->position);
if (!t) {
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_EOF;
// This function does not consume any tokens, not rewind
return res;
}
res.result = PARSER_OK;
res.value.token = t;
return res;
}
ParserResult assume_token(Parser *parser, TokenKind kind) {
ParserResult res = current_token(parser);
if (res.result == PARSER_ERROR) {
return res;
}
Token* t = res.value.token;
if (t->kind != kind) {
res.result = PARSER_ERROR;
res.error.kind = PARSER_ERROR_KIND_UNEXPECTED;
res.error.value.unexpected.token = t;
// This function does not consume any tokens, not rewind
return res;
}
return res;
}
void forward_token(Parser *parser) {
parser->position++;
}
state_t save_state(Parser *parser) {
return parser->position;
}
void rewind_state(Parser *parser, state_t state) {
parser->position = state;
}
void debug_print_current_token(Parser *parser) {
fprintf(DEBUGOUT, "DEBUG_PRINT: CURRENT_TOKEN ");
ParserResult res = current_token(parser);
if (res.result == PARSER_ERROR) {
fprintf(DEBUGOUT, "ERR!\n");
return;
}
fprintf(DEBUGOUT, "OK! -> ");
token_fprint_buf(DEBUGOUT, res.value.token);
fprintf(DEBUGOUT, "\n");
}