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dotfiles/.config/nvim/treesitter/dockerfile/scanner.c
2026-01-30 15:47:24 +03:00

343 lines
10 KiB
C

// https://github.com/faergeek/tree-sitter-dockerfile/tree/make-language-injections-easier
// https://github.com/camdencheek/tree-sitter-dockerfile
//
// The MIT License (MIT)
//
// Copyright (c) 2021 Camden Cheek
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <wctype.h>
#include "tree_sitter/parser.h"
#define MAX_HEREDOCS 10
#define DEL_SPACE 512
typedef struct {
bool in_heredoc;
bool stripping_heredoc;
unsigned heredoc_count;
char *heredocs[MAX_HEREDOCS];
} scanner_state;
enum TokenType {
HEREDOC_MARKER,
HEREDOC_LINE,
HEREDOC_END,
HEREDOC_NL,
ERROR_SENTINEL,
};
void *tree_sitter_dockerfile_external_scanner_create() {
scanner_state *state = malloc(sizeof(scanner_state));
memset(state, 0, sizeof(scanner_state));
return state;
}
void tree_sitter_dockerfile_external_scanner_destroy(void *payload) {
if (!payload)
return;
scanner_state *state = payload;
for (unsigned i = 0; i < MAX_HEREDOCS; i++) {
if (state->heredocs[i]) {
free(state->heredocs[i]);
}
}
free(state);
}
unsigned tree_sitter_dockerfile_external_scanner_serialize(void *payload,
char *buffer) {
scanner_state *state = payload;
unsigned pos = 0;
buffer[pos++] = state->in_heredoc;
buffer[pos++] = state->stripping_heredoc;
for (unsigned i = 0; i < state->heredoc_count; i++) {
// Add the ending null byte to the length since we'll have to copy it as
// well.
unsigned len = strlen(state->heredocs[i]) + 1;
// If we run out of space, just drop the heredocs that don't fit.
// We need at least len + 1 bytes space since we'll copy len bytes below
// and later add a null byte at the end.
if (pos + len + 1 > TREE_SITTER_SERIALIZATION_BUFFER_SIZE) {
break;
}
memcpy(&buffer[pos], state->heredocs[i], len);
pos += len;
}
// Add a null byte at the end to make it easy to detect.
buffer[pos++] = 0;
return pos;
}
void tree_sitter_dockerfile_external_scanner_deserialize(void *payload,
const char *buffer,
unsigned length) {
scanner_state *state = payload;
// Free all current heredocs to avoid leaking memory when we overwrite the
// array later.
for (unsigned i = 0; i < state->heredoc_count; i++) {
free(state->heredocs[i]);
state->heredocs[i] = NULL;
}
if (length == 0) {
state->in_heredoc = false;
state->stripping_heredoc = false;
state->heredoc_count = 0;
} else {
unsigned pos = 0;
state->in_heredoc = buffer[pos++];
state->stripping_heredoc = buffer[pos++];
unsigned heredoc_count = 0;
for (unsigned i = 0; i < MAX_HEREDOCS; i++) {
unsigned len = strlen(&buffer[pos]);
// We found the ending null byte which means that we're done.
if (len == 0)
break;
// Account for the ending null byte in strings (again).
len++;
char *heredoc = malloc(len);
memcpy(heredoc, &buffer[pos], len);
state->heredocs[i] = heredoc;
heredoc_count++;
pos += len;
}
state->heredoc_count = heredoc_count;
}
}
static void skip_whitespace(TSLexer *lexer) {
while (lexer->lookahead != '\0' && lexer->lookahead != '\n' &&
iswspace(lexer->lookahead))
lexer->advance(lexer, true);
}
static bool scan_marker(scanner_state *state, TSLexer *lexer) {
skip_whitespace(lexer);
if (lexer->lookahead != '<')
return false;
lexer->advance(lexer, false);
if (lexer->lookahead != '<')
return false;
lexer->advance(lexer, false);
bool stripping = false;
if (lexer->lookahead == '-') {
stripping = true;
lexer->advance(lexer, false);
}
int32_t quote = 0;
if (lexer->lookahead == '"' || lexer->lookahead == '\'') {
quote = lexer->lookahead;
lexer->advance(lexer, false);
}
// Reserve a reasonable amount of space for the heredoc delimiter string.
// Most heredocs (like EOF, EOT, EOS, FILE, etc.) are pretty short so we'll
// usually only need a few bytes. We're also limited to less than 1024 bytes
// by tree-sitter since our state has to fit in
// TREE_SITTER_SERIALIZATION_BUFFER_SIZE.
char delimiter[DEL_SPACE];
// We start recording the actual string at position 1 since we store whether
// it's a stripping heredoc in the first position (with either a dash or a
// space).
unsigned del_idx = 1;
while (lexer->lookahead != '\0' &&
(quote ? lexer->lookahead != quote : !iswspace(lexer->lookahead))) {
if (lexer->lookahead == '\\') {
lexer->advance(lexer, false);
if (lexer->lookahead == '\0') {
return false;
}
}
if (del_idx > 0) {
delimiter[del_idx++] = lexer->lookahead;
}
lexer->advance(lexer, false);
// If we run out of space, stop recording the delimiter but keep
// advancing the lexer to ensure that we at least parse the marker
// correctly. Reserve two bytes: one for the strip indicator and
// one for the terminating null byte.
if (del_idx >= DEL_SPACE - 2) {
del_idx = 0;
}
}
if (quote) {
if (lexer->lookahead != quote) {
return false;
}
lexer->advance(lexer, false);
}
if (del_idx == 0) {
lexer->result_symbol = HEREDOC_MARKER;
return true;
}
delimiter[0] = stripping ? '-' : ' ';
delimiter[del_idx] = '\0';
// We copy the delimiter string to the heap here since we can't store our
// stack-allocated string in our state (which is stored on the heap).
char *del_copy = malloc(del_idx + 1);
memcpy(del_copy, delimiter, del_idx + 1);
if (state->heredoc_count == 0) {
state->heredoc_count = 1;
state->heredocs[0] = del_copy;
state->stripping_heredoc = stripping;
} else if (state->heredoc_count >= MAX_HEREDOCS) {
free(del_copy);
} else {
state->heredocs[state->heredoc_count++] = del_copy;
}
lexer->result_symbol = HEREDOC_MARKER;
return true;
}
static bool scan_content(scanner_state *state, TSLexer *lexer,
const bool *valid_symbols) {
if (state->heredoc_count == 0) {
state->in_heredoc = false;
return false;
}
state->in_heredoc = true;
if (state->stripping_heredoc) {
skip_whitespace(lexer);
}
if (valid_symbols[HEREDOC_END]) {
unsigned delim_idx = 1;
// Look for the current heredoc delimiter.
while (state->heredocs[0][delim_idx] != '\0' &&
lexer->lookahead != '\0' &&
lexer->lookahead == state->heredocs[0][delim_idx]) {
lexer->advance(lexer, false);
delim_idx++;
}
// Check if the entire string matched.
if (state->heredocs[0][delim_idx] == '\0') {
lexer->result_symbol = HEREDOC_END;
// Shift the first heredoc off the list.
free(state->heredocs[0]);
for (unsigned i = 1; i < state->heredoc_count; i++) {
state->heredocs[i - 1] = state->heredocs[i];
}
state->heredocs[state->heredoc_count - 1] = NULL;
state->heredoc_count--;
if (state->heredoc_count > 0) {
state->stripping_heredoc = state->heredocs[0][0] == '-';
} else {
state->in_heredoc = false;
}
return true;
}
}
if (!valid_symbols[HEREDOC_LINE])
return false;
lexer->result_symbol = HEREDOC_LINE;
for (;;) {
switch (lexer->lookahead) {
case '\0':
if (lexer->eof(lexer)) {
state->in_heredoc = false;
return true;
}
lexer->advance(lexer, false);
break;
case '\n':
return true;
default:
lexer->advance(lexer, false);
}
}
}
bool tree_sitter_dockerfile_external_scanner_scan(void *payload, TSLexer *lexer,
const bool *valid_symbols) {
scanner_state *state = payload;
if (valid_symbols[ERROR_SENTINEL]) {
if (state->in_heredoc) {
return scan_content(state, lexer, valid_symbols);
} else {
return scan_marker(state, lexer);
}
}
// HEREDOC_NL only matches a linebreak if there are open heredocs. This is
// necessary to avoid a conflict in the grammar since a normal line break
// could either be the start of a heredoc or the end of an instruction.
if (valid_symbols[HEREDOC_NL]) {
if (state->heredoc_count > 0 && lexer->lookahead == '\n') {
lexer->result_symbol = HEREDOC_NL;
lexer->advance(lexer, false);
return true;
}
}
if (valid_symbols[HEREDOC_MARKER]) {
return scan_marker(state, lexer);
}
if (valid_symbols[HEREDOC_LINE] || valid_symbols[HEREDOC_END]) {
return scan_content(state, lexer, valid_symbols);
}
return false;
}