#include "strbuffer.h"
#include "utf.h"
+#define STREAM_STATE_OK 0
+#define STREAM_STATE_EOF -1
+#define STREAM_STATE_ERROR -2
+
#define TOKEN_INVALID -1
#define TOKEN_EOF 0
#define TOKEN_STRING 256
#define TOKEN_FALSE 260
#define TOKEN_NULL 261
-/* read one byte from stream, return EOF on end of file */
+/* Read one byte from stream, convert to unsigned char, then int, and
+ return. return EOF on end of file. This corresponds to the
+ behaviour of fgetc(). */
typedef int (*get_func)(void *data);
-/* return non-zero if end of file has been reached */
-typedef int (*eof_func)(void *data);
-
typedef struct {
get_func get;
- eof_func eof;
void *data;
- int stream_pos;
char buffer[5];
int buffer_pos;
+ int state;
+ int line;
+ int column, last_column;
+ size_t position;
} stream_t;
-
typedef struct {
stream_t stream;
strbuffer_t saved_text;
int token;
- int line, column;
union {
char *string;
json_int_t integer;
} value;
} lex_t;
+#define stream_to_lex(stream) container_of(stream, lex_t, stream)
+
/*** error reporting ***/
char msg_text[JSON_ERROR_TEXT_LENGTH];
int line = -1, col = -1;
+ size_t pos = 0;
const char *result = msg_text;
if(!error)
const char *saved_text = strbuffer_value(&lex->saved_text);
char msg_with_context[JSON_ERROR_TEXT_LENGTH];
- line = lex->line;
+ line = lex->stream.line;
+ col = lex->stream.column;
+ pos = lex->stream.position;
if(saved_text && saved_text[0])
{
}
else
{
- snprintf(msg_with_context, JSON_ERROR_TEXT_LENGTH,
- "%s near end of file", msg_text);
- result = msg_with_context;
+ if(lex->stream.state == STREAM_STATE_ERROR) {
+ /* No context for UTF-8 decoding errors */
+ result = msg_text;
+ }
+ else {
+ snprintf(msg_with_context, JSON_ERROR_TEXT_LENGTH,
+ "%s near end of file", msg_text);
+ result = msg_with_context;
+ }
}
}
- jsonp_error_set(error, line, col, "%s", result);
+ jsonp_error_set(error, line, col, pos, "%s", result);
}
/*** lexical analyzer ***/
static void
-stream_init(stream_t *stream, get_func get, eof_func eof, void *data)
+stream_init(stream_t *stream, get_func get, void *data)
{
stream->get = get;
- stream->eof = eof;
stream->data = data;
- stream->stream_pos = 0;
stream->buffer[0] = '\0';
stream->buffer_pos = 0;
+
+ stream->state = STREAM_STATE_OK;
+ stream->line = 1;
+ stream->column = 0;
+ stream->position = 0;
}
-static char stream_get(stream_t *stream, json_error_t *error)
+static int stream_get(stream_t *stream, json_error_t *error)
{
- char c;
+ int c;
+
+ if(stream->state != STREAM_STATE_OK)
+ return stream->state;
if(!stream->buffer[stream->buffer_pos])
{
- stream->buffer[0] = stream->get(stream->data);
- stream->buffer_pos = 0;
+ c = stream->get(stream->data);
+ if(c == EOF) {
+ stream->state = STREAM_STATE_EOF;
+ return STREAM_STATE_EOF;
+ }
- c = stream->buffer[0];
+ stream->buffer[0] = c;
+ stream->buffer_pos = 0;
- if((unsigned char)c >= 0x80 && c != (char)EOF)
+ if(0x80 <= c && c <= 0xFF)
{
/* multi-byte UTF-8 sequence */
int i, count;
if(!utf8_check_full(stream->buffer, count, NULL))
goto out;
- stream->stream_pos += count;
stream->buffer[count] = '\0';
}
- else {
+ else
stream->buffer[1] = '\0';
- stream->stream_pos++;
- }
}
- return stream->buffer[stream->buffer_pos++];
+ c = stream->buffer[stream->buffer_pos++];
-out:
- error_set(error, NULL, "unable to decode byte 0x%x at position %d",
- (unsigned char)c, stream->stream_pos);
+ stream->position++;
+ if(c == '\n') {
+ stream->line++;
+ stream->last_column = stream->column;
+ stream->column = 0;
+ }
+ else if(utf8_check_first(c)) {
+ /* track the Unicode character column, so increment only if
+ this is the first character of a UTF-8 sequence */
+ stream->column++;
+ }
- stream->buffer[0] = EOF;
- stream->buffer[1] = '\0';
- stream->buffer_pos = 1;
+ return c;
- return EOF;
+out:
+ stream->state = STREAM_STATE_ERROR;
+ error_set(error, stream_to_lex(stream), "unable to decode byte 0x%x", c);
+ return STREAM_STATE_ERROR;
}
-static void stream_unget(stream_t *stream, char c)
+static void stream_unget(stream_t *stream, int c)
{
+ if(c == STREAM_STATE_EOF || c == STREAM_STATE_ERROR)
+ return;
+
+ stream->position--;
+ if(c == '\n') {
+ stream->line--;
+ stream->column = stream->last_column;
+ }
+ else if(utf8_check_first(c))
+ stream->column--;
+
assert(stream->buffer_pos > 0);
stream->buffer_pos--;
assert(stream->buffer[stream->buffer_pos] == c);
return stream_get(&lex->stream, error);
}
-static int lex_eof(lex_t *lex)
-{
- return lex->stream.eof(lex->stream.data);
-}
-
-static void lex_save(lex_t *lex, char c)
+static void lex_save(lex_t *lex, int c)
{
strbuffer_append_byte(&lex->saved_text, c);
}
static int lex_get_save(lex_t *lex, json_error_t *error)
{
- char c = stream_get(&lex->stream, error);
- lex_save(lex, c);
+ int c = stream_get(&lex->stream, error);
+ if(c != STREAM_STATE_EOF && c != STREAM_STATE_ERROR)
+ lex_save(lex, c);
return c;
}
-static void lex_unget_unsave(lex_t *lex, char c)
+static void lex_unget(lex_t *lex, int c)
{
- char d;
stream_unget(&lex->stream, c);
- d = strbuffer_pop(&lex->saved_text);
- assert(c == d);
+}
+
+static void lex_unget_unsave(lex_t *lex, int c)
+{
+ if(c != STREAM_STATE_EOF && c != STREAM_STATE_ERROR) {
+ char d;
+ stream_unget(&lex->stream, c);
+ d = strbuffer_pop(&lex->saved_text);
+ assert(c == d);
+ }
}
static void lex_save_cached(lex_t *lex)
{
lex_save(lex, lex->stream.buffer[lex->stream.buffer_pos]);
lex->stream.buffer_pos++;
+ lex->stream.position++;
}
}
static void lex_scan_string(lex_t *lex, json_error_t *error)
{
- char c;
+ int c;
const char *p;
char *t;
int i;
c = lex_get_save(lex, error);
while(c != '"') {
- if(c == (char)EOF) {
- lex_unget_unsave(lex, c);
- if(lex_eof(lex))
- error_set(error, lex, "premature end of input");
+ if(c == STREAM_STATE_ERROR)
+ goto out;
+
+ else if(c == STREAM_STATE_EOF) {
+ error_set(error, lex, "premature end of input");
goto out;
}
- else if((unsigned char)c <= 0x1F) {
+ else if(0 <= c && c <= 0x1F) {
/* control character */
lex_unget_unsave(lex, c);
if(c == '\n')
c = lex_get_save(lex, error);
for(i = 0; i < 4; i++) {
if(!isxdigit(c)) {
- lex_unget_unsave(lex, c);
error_set(error, lex, "invalid escape");
goto out;
}
c == 'f' || c == 'n' || c == 'r' || c == 't')
c = lex_get_save(lex, error);
else {
- lex_unget_unsave(lex, c);
error_set(error, lex, "invalid escape");
goto out;
}
#define json_strtoint strtol
#endif
-static int lex_scan_number(lex_t *lex, char c, json_error_t *error)
+static int lex_scan_number(lex_t *lex, int c, json_error_t *error)
{
const char *saved_text;
char *end;
c = lex_get_save(lex, error);
}
else {
- lex_unget_unsave(lex, c);
- goto out;
+ lex_unget_unsave(lex, c);
+ goto out;
}
if(c != '.' && c != 'E' && c != 'e') {
if(c == '.') {
c = lex_get(lex, error);
- if(!isdigit(c))
+ if(!isdigit(c)) {
+ lex_unget(lex, c);
goto out;
+ }
lex_save(lex, c);
c = lex_get_save(lex, error);
static int lex_scan(lex_t *lex, json_error_t *error)
{
- char c;
+ int c;
strbuffer_clear(&lex->saved_text);
c = lex_get(lex, error);
while(c == ' ' || c == '\t' || c == '\n' || c == '\r')
- {
- if(c == '\n')
- lex->line++;
-
c = lex_get(lex, error);
+
+ if(c == STREAM_STATE_EOF) {
+ lex->token = TOKEN_EOF;
+ goto out;
}
- if(c == (char)EOF) {
- if(lex_eof(lex))
- lex->token = TOKEN_EOF;
- else
- lex->token = TOKEN_INVALID;
+ if(c == STREAM_STATE_ERROR) {
+ lex->token = TOKEN_INVALID;
goto out;
}
return result;
}
-static int lex_init(lex_t *lex, get_func get, eof_func eof, void *data)
+static int lex_init(lex_t *lex, get_func get, void *data)
{
- stream_init(&lex->stream, get, eof, data);
+ stream_init(&lex->stream, get, data);
if(strbuffer_init(&lex->saved_text))
return -1;
lex->token = TOKEN_INVALID;
- lex->line = 1;
-
return 0;
}
else
{
stream->pos++;
- return c;
+ return (unsigned char)c;
}
}
-static int string_eof(void *data)
-{
- string_data_t *stream = (string_data_t *)data;
- return (stream->data[stream->pos] == '\0');
-}
-
json_t *json_loads(const char *string, size_t flags, json_error_t *error)
{
lex_t lex;
(void)flags; /* unused */
- if(lex_init(&lex, string_get, string_eof, (void *)&stream_data))
+ if(lex_init(&lex, string_get, (void *)&stream_data))
return NULL;
jsonp_error_init(error, "<string>");
json_t *result;
(void)flags; /* unused */
- if(lex_init(&lex, (get_func)fgetc, (eof_func)feof, input))
+ if(lex_init(&lex, (get_func)fgetc, input))
return NULL;
if(input == stdin)
projects / jansson.git / blobdiff