Merge pull request #35 from tree-sitter/handle-invalid-chars-at-eof

Handle invalid chars at EOF
This commit is contained in:
Max Brunsfeld 2016-09-04 11:05:11 -07:00 committed by GitHub
commit f8b85965a3
9 changed files with 94 additions and 112 deletions

View file

@ -28,19 +28,11 @@ typedef struct {
bool structural : 1;
} TSSymbolMetadata;
typedef enum {
TSTransitionTypeMain,
TSTransitionTypeSeparator,
TSTransitionTypeError,
} TSTransitionType;
typedef struct TSLexer {
void (*advance)(struct TSLexer *, TSStateId, TSTransitionType);
void (*advance)(struct TSLexer *, TSStateId, bool);
TSLength current_position;
TSLength token_end_position;
TSLength token_start_position;
TSLength error_end_position;
const char *chunk;
size_t chunk_start;
@ -48,10 +40,7 @@ typedef struct TSLexer {
size_t lookahead_size;
int32_t lookahead;
TSStateId starting_state;
TSSymbol result_symbol;
bool result_follows_error;
int32_t first_unexpected_character;
TSInput input;
TSDebugger debugger;
@ -94,7 +83,7 @@ struct TSLanguage {
const unsigned short *parse_table;
const TSParseActionEntry *parse_actions;
const TSStateId *lex_states;
bool (*lex_fn)(TSLexer *, TSStateId, bool);
bool (*lex_fn)(TSLexer *, TSStateId);
};
/*
@ -106,22 +95,18 @@ struct TSLanguage {
next_state: \
lookahead = lexer->lookahead;
#define GO_TO_STATE(state_value) \
{ \
#define ADVANCE(state_value) \
{ \
lexer->advance(lexer, state_value, false); \
state = state_value; \
goto next_state; \
}
#define ADVANCE(state_value) \
{ \
lexer->advance(lexer, state_value, TSTransitionTypeMain); \
GO_TO_STATE(state_value); \
}
#define SKIP(state_value) \
{ \
lexer->advance(lexer, state_value, TSTransitionTypeSeparator); \
GO_TO_STATE(state_value); \
lexer->advance(lexer, state_value, true); \
state = state_value; \
goto next_state; \
}
#define ACCEPT_TOKEN(symbol_value) \
@ -130,14 +115,7 @@ struct TSLanguage {
return true; \
}
#define LEX_ERROR() \
if (error_mode) { \
if (state == TS_STATE_ERROR) \
lexer->advance(lexer, state, TSTransitionTypeError); \
GO_TO_STATE(TS_STATE_ERROR); \
} else { \
return false; \
}
#define LEX_ERROR() return false
/*
* Parse Table Macros

View file

@ -162,6 +162,15 @@ describe("Parser", [&]() {
AssertThat(get_node_text(last), Equals("true"));
});
});
describe("when there is an unterminated error", [&]() {
it("maintains a consistent tree", [&]() {
ts_document_set_language(doc, get_test_language("javascript"));
set_text("a; /* b");
assert_root_node(
"(ERROR (program (expression_statement (identifier))) (UNEXPECTED EOF))");
});
});
});
describe("handling extra tokens", [&]() {

View file

@ -184,7 +184,7 @@ class CCodeGenerator {
void add_lex_function() {
line(
"static bool ts_lex(TSLexer *lexer, TSStateId state, bool error_mode) {");
"static bool ts_lex(TSLexer *lexer, TSStateId state) {");
indent([&]() {
line("START_LEXER();");
_switch("state", [&]() {

View file

@ -14,6 +14,10 @@ static inline void ts_length_set_unknown(TSLength *self) {
self->columns = 0;
}
static inline TSLength ts_length_min(TSLength len1, TSLength len2) {
return (len1.chars < len2.chars) ? len1 : len2;
}
static inline TSLength ts_length_add(TSLength len1, TSLength len2) {
TSLength result;
result.chars = len1.chars + len2.chars;

View file

@ -47,8 +47,7 @@ static void ts_lexer__get_lookahead(TSLexer *self) {
LOG_LOOKAHEAD();
}
static void ts_lexer__advance(TSLexer *self, TSStateId state,
TSTransitionType transition_type) {
static void ts_lexer__advance(TSLexer *self, TSStateId state, bool skip) {
if (self->chunk == empty_chunk)
return;
@ -56,7 +55,6 @@ static void ts_lexer__advance(TSLexer *self, TSStateId state,
if (self->lookahead_size) {
self->current_position.bytes += self->lookahead_size;
self->current_position.chars++;
if (self->lookahead == '\n') {
self->current_position.rows++;
self->current_position.columns = 0;
@ -65,25 +63,11 @@ static void ts_lexer__advance(TSLexer *self, TSStateId state,
}
}
switch (transition_type) {
case TSTransitionTypeSeparator:
if (self->result_follows_error) {
LOG("skip_error state:%d", state);
} else {
LOG("skip_separator state:%d", state);
self->token_start_position = self->current_position;
}
break;
case TSTransitionTypeError:
LOG("skip_error state:%d", state);
self->result_follows_error = true;
self->error_end_position = self->current_position;
if (!self->first_unexpected_character)
self->first_unexpected_character = self->lookahead;
break;
default:
LOG("advance state:%d", state);
break;
if (skip) {
LOG("skip_separator state:%d", state);
self->token_start_position = self->current_position;
} else {
LOG("advance state:%d", state);
}
if (self->current_position.bytes >= self->chunk_start + self->chunk_size)
@ -109,7 +93,6 @@ void ts_lexer_init(TSLexer *self) {
static inline void ts_lexer__reset(TSLexer *self, TSLength position) {
self->token_start_position = position;
self->token_end_position = position;
self->current_position = position;
self->chunk = 0;
@ -132,34 +115,12 @@ void ts_lexer_reset(TSLexer *self, TSLength position) {
void ts_lexer_start(TSLexer *self, TSStateId lex_state) {
LOG("start_lex state:%d, pos:%lu", lex_state, self->current_position.chars);
LOG_LOOKAHEAD();
self->starting_state = lex_state;
self->token_start_position = self->current_position;
self->result_follows_error = false;
self->result_symbol = 0;
self->first_unexpected_character = 0;
if (!self->chunk)
ts_lexer__get_chunk(self);
if (!self->lookahead_size)
ts_lexer__get_lookahead(self);
}
void ts_lexer_finish(TSLexer *self, TSLexerResult *result) {
result->padding =
ts_length_sub(self->token_start_position, self->token_end_position);
if (self->result_follows_error) {
result->symbol = ts_builtin_sym_error;
result->size =
ts_length_sub(self->error_end_position, self->token_start_position);
result->first_unexpected_character = self->first_unexpected_character;
ts_lexer_reset(self, self->error_end_position);
} else {
result->symbol = self->result_symbol;
result->size =
ts_length_sub(self->current_position, self->token_start_position);
self->token_end_position = self->current_position;
}
}

View file

@ -7,18 +7,10 @@ extern "C" {
#include "tree_sitter/parser.h"
typedef struct {
TSSymbol symbol;
TSLength padding;
TSLength size;
int32_t first_unexpected_character;
} TSLexerResult;
void ts_lexer_init(TSLexer *);
void ts_lexer_set_input(TSLexer *, TSInput);
void ts_lexer_reset(TSLexer *, TSLength);
void ts_lexer_start(TSLexer *, TSStateId);
void ts_lexer_finish(TSLexer *, TSLexerResult *);
#ifdef __cplusplus
}

View file

@ -242,37 +242,67 @@ static bool parser__condense_stack(Parser *self) {
return result;
}
static TSTree *parser__lex(Parser *self, TSStateId parse_state, bool error_mode) {
TSStateId state = self->language->lex_states[parse_state];
LOG("lex state:%d", state);
static TSTree *parser__lex(Parser *self, TSStateId parse_state) {
TSStateId start_state = self->language->lex_states[parse_state];
TSStateId current_state = start_state;
TSLength start_position = self->lexer.current_position;
TSLength position = start_position;
LOG("lex state:%d", start_state);
TSLength position = self->lexer.current_position;
bool skipped_error = false;
int32_t first_error_character = 0;
TSLength error_start_position, error_end_position;
ts_lexer_start(&self->lexer, state);
if (!self->language->lex_fn(&self->lexer, state, error_mode)) {
ts_lexer_reset(&self->lexer, position);
ts_lexer_start(&self->lexer, state);
assert(self->language->lex_fn(&self->lexer, TS_STATE_ERROR, true));
ts_lexer_start(&self->lexer, start_state);
while (!self->language->lex_fn(&self->lexer, current_state)) {
if (current_state != TS_STATE_ERROR) {
LOG("retry_in_error_mode");
ts_lexer_reset(&self->lexer, position);
ts_lexer_start(&self->lexer, start_state);
current_state = TS_STATE_ERROR;
continue;
}
if (self->lexer.lookahead == 0) {
self->lexer.result_symbol = ts_builtin_sym_error;
break;
}
if (self->lexer.current_position.chars == position.chars) {
if (!skipped_error) {
error_start_position = self->lexer.current_position;
first_error_character = self->lexer.lookahead;
}
skipped_error = true;
self->lexer.advance(&self->lexer, TS_STATE_ERROR, false);
error_end_position = self->lexer.current_position;
}
position = self->lexer.current_position;
}
TSLexerResult lex_result;
ts_lexer_finish(&self->lexer, &lex_result);
TSTree *result;
if (lex_result.symbol == ts_builtin_sym_error) {
result = ts_tree_make_error(lex_result.size, lex_result.padding,
lex_result.first_unexpected_character);
if (skipped_error) {
error_start_position = ts_length_min(error_start_position, self->lexer.token_start_position);
TSLength padding = ts_length_sub(error_start_position, start_position);
TSLength size = ts_length_sub(error_end_position, error_start_position);
ts_lexer_reset(&self->lexer, error_end_position);
result = ts_tree_make_error(size, padding, first_error_character);
} else {
result = ts_tree_make_leaf(
lex_result.symbol, lex_result.padding, lex_result.size,
ts_language_symbol_metadata(self->language, lex_result.symbol));
if (!result)
return NULL;
result->parse_state = parse_state;
TSSymbol symbol = self->lexer.result_symbol;
TSLength padding = ts_length_sub(self->lexer.token_start_position, start_position);
TSLength size = ts_length_sub(self->lexer.current_position, self->lexer.token_start_position);
result = ts_tree_make_leaf(symbol, padding, size,
ts_language_symbol_metadata(self->language, symbol));
}
result->first_leaf.lex_state = state;
if (!result)
return NULL;
result->parse_state = parse_state;
result->first_leaf.lex_state = start_state;
return result;
}
@ -333,8 +363,7 @@ static TSTree *parser__get_lookahead(Parser *self, StackVersion version,
ts_lexer_reset(&self->lexer, position);
TSStateId parse_state = ts_stack_top_state(self->stack, version);
bool error_mode = parse_state == TS_STATE_ERROR;
return parser__lex(self, parse_state, error_mode);
return parser__lex(self, parse_state);
error:
return NULL;

View file

@ -369,6 +369,15 @@ void ts_tree_edit(TSTree *self, TSInputEdit edit) {
}
}
static size_t ts_tree__write_char_to_string(char *s, size_t n, int32_t c) {
if (c == 0)
return snprintf(s, n, "EOF");
else if (c < 128)
return snprintf(s, n, "'%c'", c);
else
return snprintf(s, n, "%d", c);
}
static size_t ts_tree__write_to_string(const TSTree *self,
const TSLanguage *language, char *string,
size_t limit, bool is_root,
@ -386,8 +395,8 @@ static size_t ts_tree__write_to_string(const TSTree *self,
if (visible) {
if (self->symbol == ts_builtin_sym_error && self->child_count == 0 &&
self->size.chars > 0) {
cursor +=
snprintf(*writer, limit, "(UNEXPECTED '%c'", self->lookahead_char);
cursor += snprintf(*writer, limit, "(UNEXPECTED ");
cursor += ts_tree__write_char_to_string(*writer, limit, self->lookahead_char);
} else {
cursor += snprintf(*writer, limit, "(%s",
ts_language_symbol_name(language, self->symbol));

View file

@ -25,7 +25,7 @@ typedef struct TSTree {
size_t named_child_count;
union {
struct TSTree **children;
char lookahead_char;
int32_t lookahead_char;
};
TSLength padding;