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/*
* Copyright (C) 2025 Johnny Richard <johnny@johnnyrichard.com>
*
* SPDX-License-Identifier: LGPL-3.0-or-later
*
* This file is part of obe.
*
* obe is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option)
* any later version.
*
* obe is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with obe. If not, see <https://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <obe/array.h>
#include <obe/lexer.h>
#include <obe/parser.h>
#include <stdbool.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
static obe_ir_function_t obe_parser_parse_function(obe_parser_t* parser);
inline static bool expected_next_token(obe_lexer_t *lexer, obe_token_t *token,
obe_token_kind_t expected_kind);
static bool expected_token(obe_lexer_t *lexer, obe_token_t *token,
obe_token_kind_t expected_kind);
void
obe_parser_init(obe_parser_t* parser, obe_lexer_t* lexer, obe_arena_t* arena)
{
assert(parser && lexer && arena);
parser->lexer = lexer;
parser->arena = arena;
}
void
obe_parser_next_expected_token(obe_parser_t* parser,
obe_token_t* token,
obe_token_kind_t kind)
{
obe_lexer_next_token(parser->lexer, token);
if (token->kind != kind) {
fprintf(stderr,
"%s:%zu:%zu: syntax error: expected token <%s> but got <%s>.\n",
parser->lexer->filename,
token->loc.lineno + 1,
token->loc.offset - token->loc.lineoffset + 1,
obe_token_to_cstr(kind),
obe_token_to_cstr(token->kind));
exit(EXIT_FAILURE);
}
}
obe_ir_translation_unit_t*
obe_parser_parse(obe_parser_t* parser)
{
obe_ir_translation_unit_t* tu = obe_ir_translation_unit_new(parser->arena);
// FIXME: Add support to parse multiple functions
obe_array_append(tu->funcs, obe_parser_parse_function(parser));
return tu;
}
static obe_ir_function_t
obe_parser_parse_function(obe_parser_t* parser)
{
obe_token_t token;
expected_next_token(parser->lexer, &token, TOKEN_KW_FN);
expected_next_token(parser->lexer, &token, TOKEN_IDENT);
obe_ir_function_t func = { .name = token.value, .instrs = obe_array(parser->arena, obe_ir_inst_t) };
expected_next_token(parser->lexer, &token, TOKEN_LBRACE);
obe_lexer_next_token(parser->lexer, &token);
while (token.kind != TOKEN_EOF && token.kind != TOKEN_RBRACE) {
switch (token.kind) {
case TOKEN_KW_RETURN:
{
expected_next_token(parser->lexer, &token, TOKEN_IDENT);
char value[token.value.length + 1];
memcpy(value, token.value.chars, token.value.length);
value[token.value.length] = 0;
obe_ir_inst_t inst = {
.kind = OBE_IR_INST_RETURN,
.operand1 = (obe_ir_operand_t) {
.kind = OBE_IR_OPERAND_IDENT,
.value = obe_arena_strdup(parser->arena, value)
}
};
obe_array_append(func.instrs, inst);
expected_next_token(parser->lexer, &token, TOKEN_SEMICOLON);
} break;
case TOKEN_KW_BR:
{
expected_next_token(parser->lexer, &token, TOKEN_IDENT);
char op1[token.value.length + 1];
memcpy(op1, token.value.chars, token.value.length);
op1[token.value.length] = 0;
expected_next_token(parser->lexer, &token, TOKEN_LABEL);
char dest[token.value.length + 1];
memcpy(dest, token.value.chars, token.value.length);
dest[token.value.length] = 0;
expected_next_token(parser->lexer, &token, TOKEN_SEMICOLON);
obe_ir_inst_t inst = {
.kind = OBE_IR_INST_BR,
.dest = obe_arena_strdup(parser->arena, dest),
.operand1 = (obe_ir_operand_t) {
.kind = OBE_IR_OPERAND_IDENT,
.value = obe_arena_strdup(parser->arena, op1)
}
};
obe_array_append(func.instrs, inst);
} break;
case TOKEN_LABEL:
{
char label[token.value.length + 1];
memcpy(label, token.value.chars, token.value.length);
label[token.value.length] = 0;
expected_next_token(parser->lexer, &token, TOKEN_COLON);
obe_ir_inst_t inst = {
.kind = OBE_IR_INST_LABEL,
.dest = obe_arena_strdup(parser->arena, label)
};
obe_array_append(func.instrs, inst);
} break;
case TOKEN_IDENT:
{
obe_string_t val = token.value;
char dest[token.value.length + 1];
memcpy(dest, token.value.chars, token.value.length);
dest[token.value.length] = 0;
expected_next_token(parser->lexer, &token, TOKEN_COLON);
expected_next_token(parser->lexer, &token, TOKEN_INT);
expected_next_token(parser->lexer, &token, TOKEN_EQ);
expected_next_token(parser->lexer, &token, TOKEN_NUMBER);
char number[token.value.length + 1];
memcpy(number, token.value.chars, token.value.length);
number[token.value.length] = 0;
obe_ir_inst_t inst = {
.kind = OBE_IR_INST_CONST,
.type = OBE_IR_TYPE_INT,
.dest = obe_arena_strdup(parser->arena, dest),
.operand1 = (obe_ir_operand_t) {
.kind = OBE_IR_OPERAND_LITERAL,
.value = obe_arena_strdup(parser->arena, number)
}
};
obe_array_append(func.instrs, inst);
expected_next_token(parser->lexer, &token, TOKEN_SEMICOLON);
} break;
default:
{
printf("%s:%ld:%ld: token <" PRIs ">\n",
parser->lexer->filename,
token.loc.lineno + 1,
token.loc.offset - token.loc.lineoffset + 1,
PRIsARG(token.value));
}
}
obe_lexer_next_token(parser->lexer, &token);
}
expected_token(parser->lexer, &token, TOKEN_RBRACE);
return func;
}
static bool
expected_token(obe_lexer_t *lexer, obe_token_t *token, obe_token_kind_t expected_kind)
{
if (token->kind != expected_kind) {
fprintf(stderr,
"%s:%lu:%lu: syntax error: got '" PRIs "' token but expect '%s'\n",
lexer->filename,
token->loc.lineno + 1,
token->loc.offset - lexer->loc.lineoffset + 1,
PRIsARG(token->value),
obe_token_to_cstr(expected_kind));
exit(EXIT_FAILURE);
}
return true;
}
inline static bool
expected_next_token(obe_lexer_t *lexer,
obe_token_t *token,
obe_token_kind_t expected_kind)
{
obe_lexer_next_token(lexer, token);
return expected_token(lexer, token, expected_kind);
}
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