gtk2/gtk/gtkcssparser.c
Benjamin Otte 7ccb9db79e css: Rewrite the parser
Instead of relying on GScanner and its idea of syntax, code up a parser
that obeys the CSS spec.
This also has the great side effect of reporting correct line numbers
and positions.

Also included is a reorganization of the returned error values. Instead
of error values describing what type of syntax error was returned, the
code just returns SYNTAX_ERROR. Other messages exist for when actual
values don't work or when errors shouldn't be fatal due to backwards
compatibility.
2011-05-18 22:17:55 +02:00

939 lines
21 KiB
C

/* GTK - The GIMP Toolkit
* Copyright (C) 2011 Benjamin Otte <otte@gnome.org>
*
* This library 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 2 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include "gtkcssparserprivate.h"
#include <errno.h>
#include <string.h>
/* just for the errors, yay! */
#include "gtkcssprovider.h"
#define NEWLINE_CHARS "\r\n"
#define WHITESPACE_CHARS "\f \t"
#define NMSTART "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
#define NMCHAR NMSTART "01234567890-_"
#define URLCHAR NMCHAR "!#$%&*~"
#define GTK_IS_CSS_PARSER(parser) ((parser) != NULL)
struct _GtkCssParser
{
const char *data;
GtkCssParserErrorFunc error_func;
gpointer user_data;
const char *line_start;
guint line;
};
GtkCssParser *
_gtk_css_parser_new (const char *data,
GtkCssParserErrorFunc error_func,
gpointer user_data)
{
GtkCssParser *parser;
g_return_val_if_fail (data != NULL, NULL);
parser = g_slice_new0 (GtkCssParser);
parser->data = data;
parser->error_func = error_func;
parser->user_data = user_data;
parser->line_start = data;
parser->line = 1;
return parser;
}
void
_gtk_css_parser_free (GtkCssParser *parser)
{
g_return_if_fail (GTK_IS_CSS_PARSER (parser));
g_slice_free (GtkCssParser, parser);
}
gboolean
_gtk_css_parser_is_eof (GtkCssParser *parser)
{
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), TRUE);
return *parser->data == 0;
}
gboolean
_gtk_css_parser_begins_with (GtkCssParser *parser,
char c)
{
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), TRUE);
return *parser->data == c;
}
guint
_gtk_css_parser_get_line (GtkCssParser *parser)
{
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), 1);
return parser->line;
}
guint
_gtk_css_parser_get_position (GtkCssParser *parser)
{
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), 1);
return parser->data - parser->line_start;
}
void
_gtk_css_parser_error (GtkCssParser *parser,
const char *format,
...)
{
GError *error;
va_list args;
va_start (args, format);
error = g_error_new_valist (GTK_CSS_PROVIDER_ERROR,
GTK_CSS_PROVIDER_ERROR_SYNTAX,
format, args);
va_end (args);
parser->error_func (parser, error, parser->user_data);
g_error_free (error);
}
static gboolean
gtk_css_parser_new_line (GtkCssParser *parser)
{
gboolean result = FALSE;
if (*parser->data == '\r')
{
result = TRUE;
parser->data++;
}
if (*parser->data == '\n')
{
result = TRUE;
parser->data++;
}
if (result)
{
parser->line++;
parser->line_start = parser->data;
}
return result;
}
static gboolean
gtk_css_parser_skip_comment (GtkCssParser *parser)
{
if (parser->data[0] != '/' ||
parser->data[1] != '*')
return FALSE;
parser->data += 2;
while (*parser->data)
{
gsize len = strcspn (parser->data, NEWLINE_CHARS "/");
parser->data += len;
if (gtk_css_parser_new_line (parser))
continue;
parser->data++;
if (parser->data[-2] == '*')
return TRUE;
if (parser->data[0] == '*')
_gtk_css_parser_error (parser, "'/*' in comment block");
}
/* FIXME: position */
_gtk_css_parser_error (parser, "Unterminated comment");
return TRUE;
}
void
_gtk_css_parser_skip_whitespace (GtkCssParser *parser)
{
size_t len;
while (*parser->data)
{
if (gtk_css_parser_new_line (parser))
continue;
len = strspn (parser->data, WHITESPACE_CHARS);
if (len)
{
parser->data += len;
continue;
}
if (!gtk_css_parser_skip_comment (parser))
break;
}
}
gboolean
_gtk_css_parser_try (GtkCssParser *parser,
const char *string,
gboolean skip_whitespace)
{
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), FALSE);
g_return_val_if_fail (string != NULL, FALSE);
if (g_ascii_strncasecmp (parser->data, string, strlen (string)) != 0)
return FALSE;
parser->data += strlen (string);
if (skip_whitespace)
_gtk_css_parser_skip_whitespace (parser);
return TRUE;
}
static guint
get_xdigit (char c)
{
if (c >= 'a')
return c - 'a' + 10;
else if (c >= 'A')
return c - 'A' + 10;
else
return c - '0';
}
static void
_gtk_css_parser_unescape (GtkCssParser *parser,
GString *str)
{
guint i;
gunichar result = 0;
g_assert (*parser->data == '\\');
parser->data++;
for (i = 0; i < 6; i++)
{
if (!g_ascii_isxdigit (parser->data[i]))
break;
result = (result << 4) + get_xdigit (parser->data[i]);
}
if (i != 0)
{
g_string_append_unichar (str, result);
parser->data += i;
/* NB: gtk_css_parser_new_line() forward data pointer itself */
if (!gtk_css_parser_new_line (parser) &&
*parser->data &&
strchr (WHITESPACE_CHARS, *parser->data))
parser->data++;
return;
}
if (gtk_css_parser_new_line (parser))
return;
g_string_append_c (str, *parser->data);
parser->data++;
return;
}
static gboolean
_gtk_css_parser_read_char (GtkCssParser *parser,
GString * str,
const char * allowed)
{
if (*parser->data == 0)
return FALSE;
if (strchr (allowed, *parser->data))
{
g_string_append_c (str, *parser->data);
parser->data++;
return TRUE;
}
if (*parser->data >= 127)
{
gsize len = g_utf8_skip[(guint) *(guchar *) parser->data];
g_string_append_len (str, parser->data, len);
parser->data += len;
return TRUE;
}
if (*parser->data == '\\')
{
_gtk_css_parser_unescape (parser, str);
return TRUE;
}
return FALSE;
}
char *
_gtk_css_parser_try_name (GtkCssParser *parser,
gboolean skip_whitespace)
{
GString *name;
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), NULL);
name = g_string_new (NULL);
while (_gtk_css_parser_read_char (parser, name, NMCHAR))
;
if (skip_whitespace)
_gtk_css_parser_skip_whitespace (parser);
return g_string_free (name, FALSE);
}
char *
_gtk_css_parser_try_ident (GtkCssParser *parser,
gboolean skip_whitespace)
{
const char *start;
GString *ident;
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), NULL);
start = parser->data;
ident = g_string_new (NULL);
if (*parser->data == '-')
{
g_string_append_c (ident, '-');
parser->data++;
}
if (!_gtk_css_parser_read_char (parser, ident, NMSTART))
{
parser->data = start;
g_string_free (ident, TRUE);
return NULL;
}
while (_gtk_css_parser_read_char (parser, ident, NMCHAR))
;
if (skip_whitespace)
_gtk_css_parser_skip_whitespace (parser);
return g_string_free (ident, FALSE);
}
gboolean
_gtk_css_parser_is_string (GtkCssParser *parser)
{
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), FALSE);
return *parser->data == '"' || *parser->data == '\'';
}
char *
_gtk_css_parser_read_string (GtkCssParser *parser)
{
GString *str;
char quote;
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), NULL);
quote = *parser->data;
if (quote != '"' && quote != '\'')
return NULL;
parser->data++;
str = g_string_new (NULL);
while (TRUE)
{
gsize len = strcspn (parser->data, "\\'\"\n\r\f");
g_string_append_len (str, parser->data, len);
parser->data += len;
switch (*parser->data)
{
case '\\':
_gtk_css_parser_unescape (parser, str);
break;
case '"':
case '\'':
if (*parser->data == quote)
{
parser->data++;
_gtk_css_parser_skip_whitespace (parser);
return g_string_free (str, FALSE);
}
g_string_append_c (str, *parser->data);
parser->data++;
break;
case '\0':
/* FIXME: position */
_gtk_css_parser_error (parser, "Missing end quote in string.");
g_string_free (str, TRUE);
return NULL;
default:
_gtk_css_parser_error (parser,
"Invalid character in string. Must be escaped.");
g_string_free (str, TRUE);
return NULL;
}
}
g_assert_not_reached ();
return NULL;
}
char *
_gtk_css_parser_read_uri (GtkCssParser *parser)
{
char *result;
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), NULL);
if (!_gtk_css_parser_try (parser, "url(", TRUE))
{
_gtk_css_parser_error (parser, "expected 'url('");
return NULL;
}
_gtk_css_parser_skip_whitespace (parser);
if (_gtk_css_parser_is_string (parser))
{
result = _gtk_css_parser_read_string (parser);
}
else
{
GString *str = g_string_new (NULL);
while (_gtk_css_parser_read_char (parser, str, URLCHAR))
;
result = g_string_free (str, FALSE);
if (result == NULL)
_gtk_css_parser_error (parser, "not a url");
}
if (result == NULL)
return NULL;
_gtk_css_parser_skip_whitespace (parser);
if (*parser->data != ')')
{
_gtk_css_parser_error (parser, "missing ')' for url");
g_free (result);
return NULL;
}
parser->data++;
_gtk_css_parser_skip_whitespace (parser);
return result;
}
gboolean
_gtk_css_parser_try_int (GtkCssParser *parser,
int *value)
{
gint64 result;
char *end;
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), FALSE);
g_return_val_if_fail (value != NULL, FALSE);
/* strtoll parses a plus, but we are not allowed to */
if (*parser->data == '+')
return FALSE;
errno = 0;
result = g_ascii_strtoll (parser->data, &end, 10);
if (errno)
return FALSE;
if (result > G_MAXINT || result < G_MININT)
return FALSE;
if (parser->data == end)
return FALSE;
parser->data = end;
*value = result;
_gtk_css_parser_skip_whitespace (parser);
return TRUE;
}
gboolean
_gtk_css_parser_try_uint (GtkCssParser *parser,
uint *value)
{
guint64 result;
char *end;
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), FALSE);
g_return_val_if_fail (value != NULL, FALSE);
errno = 0;
result = g_ascii_strtoull (parser->data, &end, 10);
if (errno)
return FALSE;
if (result > G_MAXUINT)
return FALSE;
if (parser->data == end)
return FALSE;
parser->data = end;
*value = result;
_gtk_css_parser_skip_whitespace (parser);
return TRUE;
}
gboolean
_gtk_css_parser_try_double (GtkCssParser *parser,
gdouble *value)
{
gdouble result;
char *end;
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), FALSE);
g_return_val_if_fail (value != NULL, FALSE);
errno = 0;
result = g_ascii_strtod (parser->data, &end);
if (errno)
return FALSE;
if (parser->data == end)
return FALSE;
parser->data = end;
*value = result;
_gtk_css_parser_skip_whitespace (parser);
return TRUE;
}
typedef enum {
COLOR_RGBA,
COLOR_RGB,
COLOR_LIGHTER,
COLOR_DARKER,
COLOR_SHADE,
COLOR_ALPHA,
COLOR_MIX
} ColorType;
static GtkSymbolicColor *
gtk_css_parser_read_symbolic_color_function (GtkCssParser *parser,
ColorType color)
{
GtkSymbolicColor *symbolic;
GtkSymbolicColor *child1, *child2;
double value;
if (!_gtk_css_parser_try (parser, "(", TRUE))
{
_gtk_css_parser_error (parser, "Missing opening bracket in color definition");
return NULL;
}
if (color == COLOR_RGB || color == COLOR_RGBA)
{
GdkRGBA rgba;
double tmp;
guint i;
for (i = 0; i < 3; i++)
{
if (i > 0 && !_gtk_css_parser_try (parser, ",", TRUE))
{
_gtk_css_parser_error (parser, "Expected ',' in color definition");
return NULL;
}
if (!_gtk_css_parser_try_double (parser, &tmp))
{
_gtk_css_parser_error (parser, "Invalid number for color value");
return NULL;
}
if (_gtk_css_parser_try (parser, "%", TRUE))
tmp /= 100.0;
else
tmp /= 255.0;
if (i == 0)
rgba.red = tmp;
else if (i == 1)
rgba.green = tmp;
else if (i == 2)
rgba.blue = tmp;
else
g_assert_not_reached ();
}
if (color == COLOR_RGBA)
{
if (i > 0 && !_gtk_css_parser_try (parser, ",", TRUE))
{
_gtk_css_parser_error (parser, "Expected ',' in color definition");
return NULL;
}
if (!_gtk_css_parser_try_double (parser, &rgba.alpha))
{
_gtk_css_parser_error (parser, "Invalid number for alpha value");
return NULL;
}
}
else
rgba.alpha = 1.0;
symbolic = gtk_symbolic_color_new_literal (&rgba);
}
else
{
child1 = _gtk_css_parser_read_symbolic_color (parser);
if (child1 == NULL)
return NULL;
if (color == COLOR_MIX)
{
if (!_gtk_css_parser_try (parser, ",", TRUE))
{
_gtk_css_parser_error (parser, "Expected ',' in color definition");
gtk_symbolic_color_unref (child1);
return NULL;
}
child2 = _gtk_css_parser_read_symbolic_color (parser);
if (child2 == NULL)
{
g_object_unref (child1);
return NULL;
}
}
else
child2 = NULL;
if (color == COLOR_LIGHTER)
value = 1.3;
else if (color == COLOR_DARKER)
value = 0.7;
else
{
if (!_gtk_css_parser_try (parser, ",", TRUE))
{
_gtk_css_parser_error (parser, "Expected ',' in color definition");
gtk_symbolic_color_unref (child1);
if (child2)
gtk_symbolic_color_unref (child2);
return NULL;
}
if (!_gtk_css_parser_try_double (parser, &value))
{
_gtk_css_parser_error (parser, "Expected number in color definition");
gtk_symbolic_color_unref (child1);
if (child2)
gtk_symbolic_color_unref (child2);
return NULL;
}
}
switch (color)
{
case COLOR_LIGHTER:
case COLOR_DARKER:
case COLOR_SHADE:
symbolic = gtk_symbolic_color_new_shade (child1, value);
break;
case COLOR_ALPHA:
symbolic = gtk_symbolic_color_new_alpha (child1, value);
break;
case COLOR_MIX:
symbolic = gtk_symbolic_color_new_mix (child1, child2, value);
break;
default:
g_assert_not_reached ();
symbolic = NULL;
}
gtk_symbolic_color_unref (child1);
if (child2)
gtk_symbolic_color_unref (child2);
}
if (!_gtk_css_parser_try (parser, ")", TRUE))
{
gtk_symbolic_color_unref (symbolic);
return NULL;
}
return symbolic;
}
static GtkSymbolicColor *
gtk_css_parser_try_hash_color (GtkCssParser *parser)
{
if (parser->data[0] == '#' &&
g_ascii_isxdigit (parser->data[1]) &&
g_ascii_isxdigit (parser->data[2]) &&
g_ascii_isxdigit (parser->data[3]))
{
GdkRGBA rgba;
if (g_ascii_isxdigit (parser->data[4]) &&
g_ascii_isxdigit (parser->data[5]) &&
g_ascii_isxdigit (parser->data[6]))
{
rgba.red = ((get_xdigit (parser->data[1]) << 4) + get_xdigit (parser->data[2])) / 255.0;
rgba.green = ((get_xdigit (parser->data[3]) << 4) + get_xdigit (parser->data[4])) / 255.0;
rgba.blue = ((get_xdigit (parser->data[5]) << 4) + get_xdigit (parser->data[6])) / 255.0;
rgba.alpha = 1.0;
parser->data += 7;
}
else
{
rgba.red = get_xdigit (parser->data[1]) / 15.0;
rgba.green = get_xdigit (parser->data[2]) / 15.0;
rgba.blue = get_xdigit (parser->data[3]) / 15.0;
rgba.alpha = 1.0;
parser->data += 4;
}
_gtk_css_parser_skip_whitespace (parser);
return gtk_symbolic_color_new_literal (&rgba);
}
return NULL;
}
GtkSymbolicColor *
_gtk_css_parser_read_symbolic_color (GtkCssParser *parser)
{
GtkSymbolicColor *symbolic;
guint color;
const char *names[] = {"rgba", "rgb", "lighter", "darker", "shade", "alpha", "mix" };
char *name;
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), NULL);
if (_gtk_css_parser_try (parser, "@", FALSE))
{
name = _gtk_css_parser_try_name (parser, TRUE);
if (name)
{
symbolic = gtk_symbolic_color_new_name (name);
}
else
{
_gtk_css_parser_error (parser, "'%s' is not a valid symbolic color name", name);
symbolic = NULL;
}
g_free (name);
return symbolic;
}
for (color = 0; color < G_N_ELEMENTS (names); color++)
{
if (_gtk_css_parser_try (parser, names[color], TRUE))
break;
}
if (color < G_N_ELEMENTS (names))
return gtk_css_parser_read_symbolic_color_function (parser, color);
symbolic = gtk_css_parser_try_hash_color (parser);
if (symbolic)
return symbolic;
name = _gtk_css_parser_try_name (parser, TRUE);
if (name)
{
GdkRGBA rgba;
if (gdk_rgba_parse (&rgba, name))
{
symbolic = gtk_symbolic_color_new_literal (&rgba);
}
else
{
_gtk_css_parser_error (parser, "'%s' is not a valid color name", name);
symbolic = NULL;
}
g_free (name);
return symbolic;
}
_gtk_css_parser_error (parser, "Not a color definition");
return NULL;
}
void
_gtk_css_parser_resync_internal (GtkCssParser *parser,
gboolean sync_at_semicolon,
gboolean read_sync_token,
char terminator)
{
gsize len;
do {
len = strcspn (parser->data, "\\\"'/()[]{};" NEWLINE_CHARS);
parser->data += len;
if (gtk_css_parser_new_line (parser))
continue;
if (_gtk_css_parser_is_string (parser))
{
/* Hrm, this emits errors, and i suspect it shouldn't... */
char *free_me = _gtk_css_parser_read_string (parser);
g_free (free_me);
continue;
}
if (gtk_css_parser_skip_comment (parser))
continue;
switch (*parser->data)
{
case '/':
{
GString *ignore = g_string_new (NULL);
_gtk_css_parser_unescape (parser, ignore);
g_string_free (ignore, TRUE);
}
break;
case ';':
if (sync_at_semicolon && !read_sync_token)
return;
parser->data++;
if (sync_at_semicolon)
{
_gtk_css_parser_skip_whitespace (parser);
return;
}
break;
case '(':
parser->data++;
_gtk_css_parser_resync (parser, FALSE, ')');
parser->data++;
break;
case '[':
parser->data++;
_gtk_css_parser_resync (parser, FALSE, ']');
parser->data++;
break;
case '{':
parser->data++;
_gtk_css_parser_resync (parser, FALSE, '}');
parser->data++;
if (sync_at_semicolon || !terminator)
{
_gtk_css_parser_skip_whitespace (parser);
return;
}
break;
case '}':
case ')':
case ']':
if (terminator == *parser->data)
{
_gtk_css_parser_skip_whitespace (parser);
return;
}
parser->data++;
continue;
default:
break;
}
} while (*parser->data);
}
char *
_gtk_css_parser_read_value (GtkCssParser *parser)
{
const char *start;
char *result;
g_return_val_if_fail (GTK_IS_CSS_PARSER (parser), NULL);
start = parser->data;
/* This needs to be done better */
_gtk_css_parser_resync_internal (parser, TRUE, FALSE, '}');
result = g_strndup (start, parser->data - start);
if (result)
{
g_strchomp (result);
if (result[0] == 0)
{
g_free (result);
result = NULL;
}
}
if (result == NULL)
_gtk_css_parser_error (parser, "Expected a property value");
return result;
}
void
_gtk_css_parser_resync (GtkCssParser *parser,
gboolean sync_at_semicolon,
char terminator)
{
g_return_if_fail (GTK_IS_CSS_PARSER (parser));
_gtk_css_parser_resync_internal (parser, sync_at_semicolon, TRUE, terminator);
}