eBookReaderSwitch/mupdf/source/html/css-parse.c

964 lines
19 KiB
C
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#include "mupdf/fitz.h"
#include "html-imp.h"
#include <string.h>
struct lexbuf
{
fz_context *ctx;
fz_pool *pool;
const unsigned char *s;
const char *file;
int line;
int lookahead;
int c;
int string_len;
char string[1024];
};
static fz_css_value *parse_expr(struct lexbuf *buf);
static fz_css_selector *parse_selector(struct lexbuf *buf);
FZ_NORETURN static void fz_css_error(struct lexbuf *buf, const char *msg)
{
fz_throw(buf->ctx, FZ_ERROR_SYNTAX, "css syntax error: %s (%s:%d)", msg, buf->file, buf->line);
}
fz_css *fz_new_css(fz_context *ctx)
{
fz_pool *pool = fz_new_pool(ctx);
fz_css *css = NULL;
fz_try(ctx)
{
css = fz_pool_alloc(ctx, pool, sizeof *css);
css->pool = pool;
css->rule = NULL;
}
fz_catch(ctx)
{
fz_drop_pool(ctx, pool);
fz_rethrow(ctx);
}
return css;
}
void fz_drop_css(fz_context *ctx, fz_css *css)
{
if (css)
fz_drop_pool(ctx, css->pool);
}
static fz_css_rule *fz_new_css_rule(fz_context *ctx, fz_pool *pool, fz_css_selector *selector, fz_css_property *declaration)
{
fz_css_rule *rule = fz_pool_alloc(ctx, pool, sizeof *rule);
rule->selector = selector;
rule->declaration = declaration;
rule->next = NULL;
return rule;
}
static fz_css_selector *fz_new_css_selector(fz_context *ctx, fz_pool *pool, const char *name)
{
fz_css_selector *sel = fz_pool_alloc(ctx, pool, sizeof *sel);
sel->name = name ? fz_pool_strdup(ctx, pool, name) : NULL;
sel->combine = 0;
sel->cond = NULL;
sel->left = NULL;
sel->right = NULL;
sel->next = NULL;
return sel;
}
static fz_css_condition *fz_new_css_condition(fz_context *ctx, fz_pool *pool, int type, const char *key, const char *val)
{
fz_css_condition *cond = fz_pool_alloc(ctx, pool, sizeof *cond);
cond->type = type;
cond->key = key ? fz_pool_strdup(ctx, pool, key) : NULL;
cond->val = val ? fz_pool_strdup(ctx, pool, val) : NULL;
cond->next = NULL;
return cond;
}
static fz_css_property *fz_new_css_property(fz_context *ctx, fz_pool *pool, const char *name, fz_css_value *value, int spec)
{
fz_css_property *prop = fz_pool_alloc(ctx, pool, sizeof *prop);
prop->name = fz_pool_strdup(ctx, pool, name);
prop->value = value;
prop->spec = spec;
prop->important = 0;
prop->next = NULL;
return prop;
}
static fz_css_value *fz_new_css_value_x(fz_context *ctx, fz_pool *pool, int type)
{
fz_css_value *val = fz_pool_alloc(ctx, pool, sizeof *val);
val->type = type;
val->data = NULL;
val->args = NULL;
val->next = NULL;
return val;
}
static fz_css_value *fz_new_css_value(fz_context *ctx, fz_pool *pool, int type, const char *data)
{
fz_css_value *val = fz_pool_alloc(ctx, pool, sizeof *val);
val->type = type;
val->data = fz_pool_strdup(ctx, pool, data);
val->args = NULL;
val->next = NULL;
return val;
}
static void css_lex_next(struct lexbuf *buf)
{
buf->c = *(buf->s++);
if (buf->c == '\n')
++buf->line;
}
static void css_lex_init(fz_context *ctx, struct lexbuf *buf, fz_pool *pool, const char *s, const char *file)
{
buf->ctx = ctx;
buf->pool = pool;
buf->s = (const unsigned char *)s;
buf->c = 0;
buf->file = file;
buf->line = 1;
css_lex_next(buf);
buf->string_len = 0;
}
static inline int iswhite(int c)
{
return c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == '\f';
}
static int isnmstart(int c)
{
return c == '\\' || c == '_' || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
(c >= 128 && c <= 255);
}
static int isnmchar(int c)
{
return c == '\\' || c == '_' || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') || c == '-' || (c >= 128 && c <= 255);
}
static void css_push_char(struct lexbuf *buf, int c)
{
if (buf->string_len + 1 >= (int)nelem(buf->string))
fz_css_error(buf, "token too long");
buf->string[buf->string_len++] = c;
}
static int css_lex_accept(struct lexbuf *buf, int t)
{
if (buf->c == t)
{
css_lex_next(buf);
return 1;
}
return 0;
}
static void css_lex_expect(struct lexbuf *buf, int t)
{
if (!css_lex_accept(buf, t))
fz_css_error(buf, "unexpected character");
}
static int css_lex_number(struct lexbuf *buf)
{
while (buf->c >= '0' && buf->c <= '9')
{
css_push_char(buf, buf->c);
css_lex_next(buf);
}
if (css_lex_accept(buf, '.'))
{
css_push_char(buf, '.');
while (buf->c >= '0' && buf->c <= '9')
{
css_push_char(buf, buf->c);
css_lex_next(buf);
}
}
if (css_lex_accept(buf, '%'))
{
css_push_char(buf, '%');
css_push_char(buf, 0);
return CSS_PERCENT;
}
if (isnmstart(buf->c))
{
css_push_char(buf, buf->c);
css_lex_next(buf);
while (isnmchar(buf->c))
{
css_push_char(buf, buf->c);
css_lex_next(buf);
}
css_push_char(buf, 0);
return CSS_LENGTH;
}
css_push_char(buf, 0);
return CSS_NUMBER;
}
static int css_lex_keyword(struct lexbuf *buf)
{
while (isnmchar(buf->c))
{
css_push_char(buf, buf->c);
css_lex_next(buf);
}
css_push_char(buf, 0);
return CSS_KEYWORD;
}
static int css_lex_hash(struct lexbuf *buf)
{
while (isnmchar(buf->c))
{
css_push_char(buf, buf->c);
css_lex_next(buf);
}
css_push_char(buf, 0);
return CSS_HASH;
}
static int css_lex_string(struct lexbuf *buf, int q)
{
while (buf->c && buf->c != q)
{
if (css_lex_accept(buf, '\\'))
{
if (css_lex_accept(buf, 'n'))
css_push_char(buf, '\n');
else if (css_lex_accept(buf, 'r'))
css_push_char(buf, '\r');
else if (css_lex_accept(buf, 'f'))
css_push_char(buf, '\f');
else if (css_lex_accept(buf, '\f'))
/* line continuation */ ;
else if (css_lex_accept(buf, '\n'))
/* line continuation */ ;
else if (css_lex_accept(buf, '\r'))
css_lex_accept(buf, '\n');
else
{
css_push_char(buf, buf->c);
css_lex_next(buf);
}
}
else
{
css_push_char(buf, buf->c);
css_lex_next(buf);
}
}
css_lex_expect(buf, q);
css_push_char(buf, 0);
return CSS_STRING;
}
static void css_lex_uri(struct lexbuf *buf)
{
while (buf->c && buf->c != ')' && !iswhite(buf->c))
{
if (css_lex_accept(buf, '\\'))
{
if (css_lex_accept(buf, 'n'))
css_push_char(buf, '\n');
else if (css_lex_accept(buf, 'r'))
css_push_char(buf, '\r');
else if (css_lex_accept(buf, 'f'))
css_push_char(buf, '\f');
else
{
css_push_char(buf, buf->c);
css_lex_next(buf);
}
}
else if (buf->c == '!' || buf->c == '#' || buf->c == '$' || buf->c == '%' || buf->c == '&' ||
(buf->c >= '*' && buf->c <= '[') ||
(buf->c >= ']' && buf->c <= '~') ||
buf->c > 159)
{
css_push_char(buf, buf->c);
css_lex_next(buf);
}
else
fz_css_error(buf, "unexpected character in url");
}
css_push_char(buf, 0);
}
static int css_lex(struct lexbuf *buf)
{
int t;
// TODO: keyword escape sequences
buf->string_len = 0;
restart:
if (buf->c == 0)
return EOF;
if (iswhite(buf->c))
{
while (iswhite(buf->c))
css_lex_next(buf);
return ' ';
}
if (css_lex_accept(buf, '/'))
{
if (css_lex_accept(buf, '*'))
{
while (buf->c)
{
if (css_lex_accept(buf, '*'))
{
while (buf->c == '*')
css_lex_next(buf);
if (css_lex_accept(buf, '/'))
goto restart;
}
css_lex_next(buf);
}
fz_css_error(buf, "unterminated comment");
}
return '/';
}
if (css_lex_accept(buf, '<'))
{
if (css_lex_accept(buf, '!'))
{
css_lex_expect(buf, '-');
css_lex_expect(buf, '-');
goto restart; /* ignore CDO */
}
return '<';
}
if (css_lex_accept(buf, '-'))
{
if (css_lex_accept(buf, '-'))
{
css_lex_expect(buf, '>');
goto restart; /* ignore CDC */
}
if (isnmstart(buf->c))
{
css_push_char(buf, '-');
return css_lex_keyword(buf);
}
return '-';
}
if (css_lex_accept(buf, '.'))
{
if (buf->c >= '0' && buf->c <= '9')
{
css_push_char(buf, '.');
return css_lex_number(buf);
}
return '.';
}
if (css_lex_accept(buf, '#'))
{
if (isnmchar(buf->c))
return css_lex_hash(buf);
return '#';
}
if (css_lex_accept(buf, '"'))
return css_lex_string(buf, '"');
if (css_lex_accept(buf, '\''))
return css_lex_string(buf, '\'');
if (buf->c >= '0' && buf->c <= '9')
return css_lex_number(buf);
if (css_lex_accept(buf, 'u'))
{
if (css_lex_accept(buf, 'r'))
{
if (css_lex_accept(buf, 'l'))
{
if (css_lex_accept(buf, '('))
{
while (iswhite(buf->c))
css_lex_next(buf);
if (css_lex_accept(buf, '"'))
css_lex_string(buf, '"');
else if (css_lex_accept(buf, '\''))
css_lex_string(buf, '\'');
else
css_lex_uri(buf);
while (iswhite(buf->c))
css_lex_next(buf);
css_lex_expect(buf, ')');
return CSS_URI;
}
css_push_char(buf, 'u');
css_push_char(buf, 'r');
css_push_char(buf, 'l');
return css_lex_keyword(buf);
}
css_push_char(buf, 'u');
css_push_char(buf, 'r');
return css_lex_keyword(buf);
}
css_push_char(buf, 'u');
return css_lex_keyword(buf);
}
if (isnmstart(buf->c))
{
css_push_char(buf, buf->c);
css_lex_next(buf);
return css_lex_keyword(buf);
}
t = buf->c;
css_lex_next(buf);
return t;
}
static void next(struct lexbuf *buf)
{
buf->lookahead = css_lex(buf);
}
static int accept(struct lexbuf *buf, int t)
{
if (buf->lookahead == t)
{
next(buf);
return 1;
}
return 0;
}
static void expect(struct lexbuf *buf, int t)
{
if (accept(buf, t))
return;
fz_css_error(buf, "unexpected token");
}
static void white(struct lexbuf *buf)
{
while (buf->lookahead == ' ')
next(buf);
}
static int iscond(int t)
{
return t == ':' || t == '.' || t == '[' || t == CSS_HASH;
}
static fz_css_value *parse_term(struct lexbuf *buf)
{
fz_css_value *v;
if (buf->lookahead == '+' || buf->lookahead == '-')
{
float sign = buf->lookahead == '-' ? -1 : 1;
next(buf);
if (buf->lookahead != CSS_NUMBER && buf->lookahead != CSS_LENGTH && buf->lookahead != CSS_PERCENT)
fz_css_error(buf, "expected number");
if (sign < 0)
{
v = fz_new_css_value_x(buf->ctx, buf->pool, buf->lookahead);
v->data = fz_pool_alloc(buf->ctx, buf->pool, strlen(buf->string) + 2);
v->data[0] = '-';
strcpy(v->data + 1, buf->string);
}
else
{
v = fz_new_css_value(buf->ctx, buf->pool, buf->lookahead, buf->string);
}
next(buf);
white(buf);
return v;
}
if (buf->lookahead == CSS_KEYWORD)
{
v = fz_new_css_value(buf->ctx, buf->pool, CSS_KEYWORD, buf->string);
next(buf);
if (accept(buf, '('))
{
white(buf);
v->type = '(';
v->args = parse_expr(buf);
expect(buf, ')');
}
white(buf);
return v;
}
switch (buf->lookahead)
{
case CSS_HASH:
case CSS_STRING:
case CSS_URI:
case CSS_NUMBER:
case CSS_LENGTH:
case CSS_PERCENT:
v = fz_new_css_value(buf->ctx, buf->pool, buf->lookahead, buf->string);
next(buf);
white(buf);
return v;
}
fz_css_error(buf, "expected value");
}
static fz_css_value *parse_expr(struct lexbuf *buf)
{
fz_css_value *head, *tail;
head = tail = parse_term(buf);
while (buf->lookahead != '}' && buf->lookahead != ';' && buf->lookahead != '!' &&
buf->lookahead != ')' && buf->lookahead != EOF)
{
if (accept(buf, ','))
{
white(buf);
tail = tail->next = fz_new_css_value(buf->ctx, buf->pool, ',', ",");
tail = tail->next = parse_term(buf);
}
else if (accept(buf, '/'))
{
white(buf);
tail = tail->next = fz_new_css_value(buf->ctx, buf->pool, '/', "/");
tail = tail->next = parse_term(buf);
}
else
{
tail = tail->next = parse_term(buf);
}
}
return head;
}
static fz_css_property *parse_declaration(struct lexbuf *buf)
{
fz_css_property *p;
if (buf->lookahead != CSS_KEYWORD)
fz_css_error(buf, "expected keyword in property");
p = fz_new_css_property(buf->ctx, buf->pool, buf->string, NULL, 0);
next(buf);
white(buf);
expect(buf, ':');
white(buf);
p->value = parse_expr(buf);
/* !important */
if (accept(buf, '!'))
{
white(buf);
if (buf->lookahead != CSS_KEYWORD || strcmp(buf->string, "important"))
fz_css_error(buf, "expected keyword 'important' after '!'");
p->important = 1;
next(buf);
white(buf);
}
return p;
}
static fz_css_property *parse_declaration_list(struct lexbuf *buf)
{
fz_css_property *head, *tail;
white(buf);
if (buf->lookahead == '}' || buf->lookahead == EOF)
return NULL;
head = tail = parse_declaration(buf);
while (accept(buf, ';'))
{
white(buf);
if (buf->lookahead != '}' && buf->lookahead != ';' && buf->lookahead != EOF)
{
tail = tail->next = parse_declaration(buf);
}
}
return head;
}
static char *parse_attrib_value(struct lexbuf *buf)
{
char *s;
if (buf->lookahead == CSS_KEYWORD || buf->lookahead == CSS_STRING)
{
s = fz_pool_strdup(buf->ctx, buf->pool, buf->string);
next(buf);
white(buf);
return s;
}
fz_css_error(buf, "expected attribute value");
}
static fz_css_condition *parse_condition(struct lexbuf *buf)
{
fz_css_condition *c;
if (accept(buf, ':'))
{
accept(buf, ':'); /* swallow css3 :: syntax and pretend it's a normal pseudo-class */
if (buf->lookahead != CSS_KEYWORD)
fz_css_error(buf, "expected keyword after ':'");
c = fz_new_css_condition(buf->ctx, buf->pool, ':', "pseudo", buf->string);
next(buf);
if (accept(buf, '('))
{
white(buf);
if (accept(buf, CSS_KEYWORD))
white(buf);
expect(buf, ')');
}
return c;
}
if (accept(buf, '.'))
{
if (buf->lookahead != CSS_KEYWORD)
fz_css_error(buf, "expected keyword after '.'");
c = fz_new_css_condition(buf->ctx, buf->pool, '.', "class", buf->string);
next(buf);
return c;
}
if (accept(buf, '['))
{
white(buf);
if (buf->lookahead != CSS_KEYWORD)
fz_css_error(buf, "expected keyword after '['");
c = fz_new_css_condition(buf->ctx, buf->pool, '[', buf->string, NULL);
next(buf);
white(buf);
if (accept(buf, '='))
{
c->type = '=';
c->val = parse_attrib_value(buf);
}
else if (accept(buf, '|'))
{
expect(buf, '=');
c->type = '|';
c->val = parse_attrib_value(buf);
}
else if (accept(buf, '~'))
{
expect(buf, '=');
c->type = '~';
c->val = parse_attrib_value(buf);
}
expect(buf, ']');
return c;
}
if (buf->lookahead == CSS_HASH)
{
c = fz_new_css_condition(buf->ctx, buf->pool, '#', "id", buf->string);
next(buf);
return c;
}
fz_css_error(buf, "expected condition");
}
static fz_css_condition *parse_condition_list(struct lexbuf *buf)
{
fz_css_condition *head, *tail;
head = tail = parse_condition(buf);
while (iscond(buf->lookahead))
{
tail = tail->next = parse_condition(buf);
}
return head;
}
static fz_css_selector *parse_simple_selector(struct lexbuf *buf)
{
fz_css_selector *s;
if (accept(buf, '*'))
{
s = fz_new_css_selector(buf->ctx, buf->pool, NULL);
if (iscond(buf->lookahead))
s->cond = parse_condition_list(buf);
return s;
}
else if (buf->lookahead == CSS_KEYWORD)
{
s = fz_new_css_selector(buf->ctx, buf->pool, buf->string);
next(buf);
if (iscond(buf->lookahead))
s->cond = parse_condition_list(buf);
return s;
}
else if (iscond(buf->lookahead))
{
s = fz_new_css_selector(buf->ctx, buf->pool, NULL);
s->cond = parse_condition_list(buf);
return s;
}
fz_css_error(buf, "expected selector");
}
static fz_css_selector *parse_combinator(struct lexbuf *buf, int c, fz_css_selector *a)
{
fz_css_selector *sel, *b;
white(buf);
b = parse_simple_selector(buf);
sel = fz_new_css_selector(buf->ctx, buf->pool, NULL);
sel->combine = c;
sel->left = a;
sel->right = b;
return sel;
}
static fz_css_selector *parse_selector(struct lexbuf *buf)
{
fz_css_selector *sel = parse_simple_selector(buf);
for (;;)
{
if (accept(buf, ' '))
{
if (accept(buf, '+'))
sel = parse_combinator(buf, '+', sel);
else if (accept(buf, '>'))
sel = parse_combinator(buf, '>', sel);
else if (buf->lookahead != ',' && buf->lookahead != '{' && buf->lookahead != EOF)
sel = parse_combinator(buf, ' ', sel);
else
break;
}
else if (accept(buf, '+'))
sel = parse_combinator(buf, '+', sel);
else if (accept(buf, '>'))
sel = parse_combinator(buf, '>', sel);
else
break;
}
return sel;
}
static fz_css_selector *parse_selector_list(struct lexbuf *buf)
{
fz_css_selector *head, *tail;
head = tail = parse_selector(buf);
while (accept(buf, ','))
{
white(buf);
tail = tail->next = parse_selector(buf);
}
return head;
}
static fz_css_rule *parse_ruleset(struct lexbuf *buf)
{
fz_css_selector *s = NULL;
fz_css_property *p = NULL;
fz_try(buf->ctx)
{
s = parse_selector_list(buf);
expect(buf, '{');
p = parse_declaration_list(buf);
expect(buf, '}');
white(buf);
}
fz_catch(buf->ctx)
{
if (fz_caught(buf->ctx) != FZ_ERROR_SYNTAX)
fz_rethrow(buf->ctx);
while (buf->lookahead != EOF)
{
if (accept(buf, '}'))
{
white(buf);
break;
}
next(buf);
}
return NULL;
}
return fz_new_css_rule(buf->ctx, buf->pool, s, p);
}
static fz_css_rule *parse_at_page(struct lexbuf *buf)
{
fz_css_selector *s = NULL;
fz_css_property *p = NULL;
white(buf);
if (accept(buf, ':'))
{
expect(buf, CSS_KEYWORD);
white(buf);
}
expect(buf, '{');
p = parse_declaration_list(buf);
expect(buf, '}');
white(buf);
s = fz_new_css_selector(buf->ctx, buf->pool, "@page");
return fz_new_css_rule(buf->ctx, buf->pool, s, p);
}
static fz_css_rule *parse_at_font_face(struct lexbuf *buf)
{
fz_css_selector *s = NULL;
fz_css_property *p = NULL;
white(buf);
expect(buf, '{');
p = parse_declaration_list(buf);
expect(buf, '}');
white(buf);
s = fz_new_css_selector(buf->ctx, buf->pool, "@font-face");
return fz_new_css_rule(buf->ctx, buf->pool, s, p);
}
static void parse_at_rule(struct lexbuf *buf)
{
expect(buf, CSS_KEYWORD);
/* skip until '{' or ';' */
while (buf->lookahead != EOF)
{
if (accept(buf, ';'))
{
white(buf);
return;
}
if (accept(buf, '{'))
{
int depth = 1;
while (buf->lookahead != EOF && depth > 0)
{
if (accept(buf, '{'))
++depth;
else if (accept(buf, '}'))
--depth;
else
next(buf);
}
white(buf);
return;
}
next(buf);
}
}
static fz_css_rule *parse_stylesheet(struct lexbuf *buf, fz_css_rule *chain)
{
fz_css_rule *rule, **nextp, *tail;
tail = chain;
if (tail)
{
while (tail->next)
tail = tail->next;
nextp = &tail->next;
}
else
{
nextp = &tail;
}
white(buf);
while (buf->lookahead != EOF)
{
if (accept(buf, '@'))
{
if (buf->lookahead == CSS_KEYWORD && !strcmp(buf->string, "page"))
{
next(buf);
rule = *nextp = parse_at_page(buf);
nextp = &rule->next;
}
else if (buf->lookahead == CSS_KEYWORD && !strcmp(buf->string, "font-face"))
{
next(buf);
rule = *nextp = parse_at_font_face(buf);
nextp = &rule->next;
}
else
{
parse_at_rule(buf);
}
}
else
{
fz_css_rule *x = parse_ruleset(buf);
if (x)
{
rule = *nextp = x;
nextp = &rule->next;
}
}
white(buf);
}
return chain ? chain : tail;
}
fz_css_property *fz_parse_css_properties(fz_context *ctx, fz_pool *pool, const char *source)
{
struct lexbuf buf;
css_lex_init(ctx, &buf, pool, source, "<inline>");
next(&buf);
return parse_declaration_list(&buf);
}
void fz_parse_css(fz_context *ctx, fz_css *css, const char *source, const char *file)
{
struct lexbuf buf;
css_lex_init(ctx, &buf, css->pool, source, file);
next(&buf);
css->rule = parse_stylesheet(&buf, css->rule);
}