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/**
* THIS FILE IS PENDING SECONDARY REVIEW. MAY CONTAIN VULNERABILITIES!
*
* Parser code is inherently more prone to vulnerabilities. This will have to be checked!!
*/
/**
* @file parser.c
* @author 0x221E
* @brief .
* @description
*
* @warning User manages the memory of the parser.
* @warning Backend manages the memory of itself.
* @warning Parser is guaranteed to provide safe memory, constrained by the length of string_view.
*/
// TODO: Count newlines, add a new field to parser struct.
#include <parser.h>
#include <err.h>
#include <net.h>
#include <lib/sv.h>
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <stddef.h>
int is_alpha(char c)
{
return (c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z');
}
int is_key_char(char c)
{
return is_alpha(c) || c == '_';
}
int is_whitespace(char c)
{
return c == ' ' || c == '\r' || c == '\t';
}
char parser_peek(struct parser *parser, size_t i)
{
size_t npos = parser->pos + i;
if(npos >= parser->len)
return parser->src[parser->pos];
return parser->src[npos];
}
char parser_advance(struct parser *parser, size_t i)
{
size_t npos = parser->pos + i;
if(npos >= parser->len)
return parser->src[parser->pos];
parser->pos = npos;
return parser->src[npos];
}
/* expects on the current position */
int parser_expect(struct parser *parser, char e)
{
assert(parser != NULL);
char c = parser_peek(parser, 0);
if(c != e)
return 1;
parser_advance(parser, 1);
return 0;
}
void parser_expect_throw(struct parser *parser, char e, const char *fail)
{
if(parser_expect(parser, e)) {
fprintf(stderr, "%s", fail);
parser->state = PARSER_STATE_ERROR;
}
}
void skip_whitespace(struct parser *parser)
{
while(parser->pos < parser->len &&
is_whitespace(parser->src[parser->pos]))
parser->pos++;
}
int parser_init(struct parser *parser,
struct string_view *mem,
struct parser_backend *backend,
void *userdata)
{
assert(parser != NULL);
assert(mem != NULL);
assert(backend != NULL);
if ((backend->on_block_start == NULL) ||
(backend->on_block_end == NULL) ||
(backend->on_kv == NULL) ||
(mem->buf == NULL))
return -PARINITERR;
parser->pos = 0;
parser->src = mem->buf;
parser->len = mem->len;
parser->state = PARSER_STATE_GRACEFUL;
parser->backend = backend;
parser->userdata = userdata;
parser->backend->on_init();
return SUCCESS;
}
int parser_parse(struct parser *parser)
{
assert(parser != NULL);
while(parser->pos < parser->len - 1) {
char c = parser_peek(parser, 0);
char nc = parser_peek(parser, 1);
if (c == '[' && nc == '/')
parser_parse_block_end(parser);
else if (c == '[')
parser_parse_block_start(parser);
else if (c == '-')
parser_parse_kv(parser);
/* else if (c == '+') */
/* parser_parse_blocklist(parser); */
else
parser_advance(parser, 1);
}
if (parser->state == PARSER_STATE_ERROR)
return -PARPARERR;
return SUCCESS;
}
void parser_parse_block_start(struct parser *parser)
{
assert(parser != NULL);
parser_expect_throw(parser, '[', "Block beginning expects a '['.");
size_t spos = parser->pos;
size_t len = 0;
while (parser->pos < parser->len &&
is_alpha(parser_peek(parser, 0))) {
parser_advance(parser, 1);
len++;
}
printf("Block start compiled with name: %.*s\n", (int)len, &parser->src[spos]);
parser_expect_throw(parser, ']', "Block beginning expects a ']'.");
parser_expect_throw(parser, '\n', "Block must be on a seperate line!");
struct string_view block_name = sv_create(&parser->src[spos], len);
parser->backend->on_block_start(&block_name, parser->userdata);
}
void parser_parse_block_end(struct parser *parser)
{
assert(parser != NULL);
parser_expect_throw(parser, '[', "Block end expects a '['.");
parser_expect_throw(parser, '/', "Block end expects a '/'.");
size_t spos = parser->pos;
size_t len = 0;
while (parser->pos < parser->len &&
is_alpha(parser_peek(parser, 0))) {
parser_advance(parser, 1);
len++;
}
printf("Block end compiled with name: %.*s\n", (int)len, &parser->src[spos]);
parser_expect_throw(parser, ']', "Block end expects a ']'.");
parser_expect_throw(parser, '\n', "Block must be on a seperate line!");
struct string_view block_name = sv_create(&parser->src[spos], len);
parser->backend->on_block_end(&block_name, parser->userdata);
}
void parser_parse_kv(struct parser *parser)
{
assert(parser != NULL);
parser_expect_throw(parser, '-', "key-value expects a '-'.");
size_t keypos = parser->pos;
size_t keylen = 0;
while (parser->pos < parser->len &&
is_key_char(parser_peek(parser, 0))) {
parser_advance(parser, 1);
keylen++;
}
parser_expect_throw(parser, '=', "key-value expects a '='.\n");
size_t valpos = parser->pos;
size_t vallen = 0;
while (parser->pos < parser->len &&
parser_peek(parser, 0) != '\n') {
parser_advance(parser, 1);
vallen++;
}
printf("Key: %.*s, value: %.*s.\n", (int)keylen, &parser->src[keypos], (int)vallen, &parser->src[valpos]);
parser_expect_throw(parser, '\n', "key-value items must be seperated with a newline character");
struct string_view key = sv_create(&parser->src[keypos], keylen);
struct string_view value = sv_create(&parser->src[valpos], vallen);
parser->backend->on_kv(&key, &value, parser->userdata);
}
/* void parser_parse_blocklist(struct parser *parser) */
/* { */
/* assert(parser != NULL); */
/* /\* parser->backend->on_blocklist(&value, parser->userdata); *\/ */
/* } */
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