diff options
Diffstat (limited to 'src/libserver/css/css_tokeniser.hxx')
| -rw-r--r-- | src/libserver/css/css_tokeniser.hxx | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/src/libserver/css/css_tokeniser.hxx b/src/libserver/css/css_tokeniser.hxx new file mode 100644 index 0000000..aa6a1a7 --- /dev/null +++ b/src/libserver/css/css_tokeniser.hxx @@ -0,0 +1,215 @@ +/*- + * Copyright 2021 Vsevolod Stakhov + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#pragma once + +#ifndef RSPAMD_CSS_TOKENISER_HXX +#define RSPAMD_CSS_TOKENISER_HXX + +#include <string_view> +#include <utility> +#include <variant> +#include <list> +#include <functional> +#include <cstdint> +#include "mem_pool.h" + +namespace rspamd::css { + +struct css_parser_token_placeholder {}; /* For empty tokens */ + +struct css_parser_token { + + enum class token_type : std::uint8_t { + whitespace_token, + ident_token, + function_token, + at_keyword_token, + hash_token, + string_token, + number_token, + url_token, + cdo_token, /* xml open comment */ + cdc_token, /* xml close comment */ + delim_token, + obrace_token, /* ( */ + ebrace_token, /* ) */ + osqbrace_token, /* [ */ + esqbrace_token, /* ] */ + ocurlbrace_token, /* { */ + ecurlbrace_token, /* } */ + comma_token, + colon_token, + semicolon_token, + eof_token, + }; + + enum class dim_type : std::uint8_t { + dim_px = 0, + dim_em, + dim_rem, + dim_ex, + dim_wv, + dim_wh, + dim_vmax, + dim_vmin, + dim_pt, + dim_cm, + dim_mm, + dim_in, + dim_pc, + dim_max, + }; + + static const std::uint8_t default_flags = 0; + static const std::uint8_t flag_bad_string = (1u << 0u); + static const std::uint8_t number_dimension = (1u << 1u); + static const std::uint8_t number_percent = (1u << 2u); + static const std::uint8_t flag_bad_dimension = (1u << 3u); + + using value_type = std::variant<std::string_view, /* For strings and string like tokens */ + char, /* For delimiters (might need to move to unicode point) */ + float, /* For numeric stuff */ + css_parser_token_placeholder /* For general no token stuff */ + >; + + /* Typed storage */ + value_type value; + + int lineno; + + token_type type; + std::uint8_t flags = default_flags; + dim_type dimension_type; + + css_parser_token() = delete; + explicit css_parser_token(token_type type, const value_type &value) + : value(value), type(type) + { + } + css_parser_token(css_parser_token &&other) = default; + css_parser_token(const css_parser_token &token) = default; + auto operator=(css_parser_token &&other) -> css_parser_token & = default; + auto adjust_dim(const css_parser_token &dim_token) -> bool; + + auto get_string_or_default(const std::string_view &def) const -> std::string_view + { + if (std::holds_alternative<std::string_view>(value)) { + return std::get<std::string_view>(value); + } + else if (std::holds_alternative<char>(value)) { + return std::string_view(&std::get<char>(value), 1); + } + + return def; + } + + auto get_delim() const -> char + { + if (std::holds_alternative<char>(value)) { + return std::get<char>(value); + } + + return (char) -1; + } + + auto get_number_or_default(float def) const -> float + { + if (std::holds_alternative<float>(value)) { + auto dbl = std::get<float>(value); + + if (flags & css_parser_token::number_percent) { + dbl /= 100.0; + } + + return dbl; + } + + return def; + } + + auto get_normal_number_or_default(float def) const -> float + { + if (std::holds_alternative<float>(value)) { + auto dbl = std::get<float>(value); + + if (flags & css_parser_token::number_percent) { + dbl /= 100.0; + } + + if (dbl < 0) { + return 0.0; + } + else if (dbl > 1.0) { + return 1.0; + } + + return dbl; + } + + return def; + } + + /* Debugging routines */ + constexpr auto get_token_type() -> const char *; + /* This function might be slow */ + auto debug_token_str() -> std::string; +}; + +static auto css_parser_eof_token(void) -> const css_parser_token & +{ + static css_parser_token eof_tok{ + css_parser_token::token_type::eof_token, + css_parser_token_placeholder()}; + + return eof_tok; +} + +/* Ensure that parser tokens are simple enough */ +/* + * compiler must implement P0602 "variant and optional should propagate copy/move triviality" + * This is broken on gcc < 8! + */ +static_assert(std::is_trivially_copyable_v<css_parser_token>); + +class css_tokeniser { +public: + css_tokeniser() = delete; + css_tokeniser(rspamd_mempool_t *pool, const std::string_view &sv) + : input(sv), offset(0), pool(pool) + { + } + + auto next_token(void) -> struct css_parser_token; + auto pushback_token(const struct css_parser_token &t) const -> void + { + backlog.push_back(t); + } + +private: + std::string_view input; + std::size_t offset; + rspamd_mempool_t *pool; + mutable std::list<css_parser_token> backlog; + + auto consume_number() -> struct css_parser_token; + auto consume_ident(bool allow_number = false) -> struct css_parser_token; +}; + +}// namespace rspamd::css + + +#endif//RSPAMD_CSS_TOKENISER_HXX |