diff options
Diffstat (limited to 'build2/test/script/regex')
| -rw-r--r-- | build2/test/script/regex | 103 |
1 files changed, 65 insertions, 38 deletions
diff --git a/build2/test/script/regex b/build2/test/script/regex index 7dacfee..7708410 100644 --- a/build2/test/script/regex +++ b/build2/test/script/regex @@ -8,6 +8,7 @@ #include <list> #include <regex> #include <locale> +#include <cstdint> // uintptr_t #include <type_traits> // make_unsigned, is_unsigned #include <unordered_set> @@ -57,37 +58,45 @@ namespace build2 struct line_char { - /* + // Steal last two bits from the pointer to store the type. + // private: - size_t data_; + std::uintptr_t data_; - // Steal two bits from the pointer (need to static assert). - // public: line_type - type () const; + type () const {return static_cast<line_type> (data_ & 0x3);} int - special () const; // Stored as (shifted) int16. + special () const + { + // Stored as (shifted) int16_t. Perform steps reversed to those + // that are described in the comment for the corresponding ctor. + // Note that the intermediate cast to uint16_t is required to + // portably preserve the -1 special character. + // + return static_cast<int16_t> (static_cast<uint16_t> (data_ >> 2)); + } const char_string* - literal () const; + literal () const + { + // Note that 2 rightmost bits are used for packaging line_char + // type. Read the comment for the corresponding ctor for details. + // + return reinterpret_cast<const char_string*> ( + data_ & ~std::uintptr_t (0x3)); + } const char_regex* - regex () const; - */ - - line_type type; - - union + regex () const { - int special; // 0 (nul character) - // -1 (EOF) - // [()|.*+?{\}0123456789,=!] (excluding []) - - const char_string* literal; - const char_regex* regex; - }; + // Note that 2 rightmost bits are used for packaging line_char + // type. Read the comment for the corresponding ctor for details. + // + return reinterpret_cast<const char_regex*> ( + data_ & ~std::uintptr_t (0x3)); + } static const line_char nul; static const line_char eof; @@ -96,7 +105,12 @@ namespace build2 // line_char () = default; - // Create a special character. + // Create a special character. The argument value must be one of the + // following ones: + // + // 0 (nul character) + // -1 (EOF) + // [()|.*+?{\}0123456789,=!] (excluding []) // // Note that the constructor is implicit to allow basic_regex to // implicitly construct line_chars from special char literals (in @@ -121,7 +135,13 @@ namespace build2 explicit line_char (const char_string* s) // Assume already pooled. - : type (line_type::literal), literal (s) {} + // + // Steal two bits from the pointer to package line_char type. + // Assume (and statically assert) that char_string address is a + // multiple of four. + // + : data_ (reinterpret_cast <std::uintptr_t> (s) | + static_cast <std::uintptr_t> (line_type::literal)) {} // Create a regex character. // @@ -130,7 +150,13 @@ namespace build2 explicit line_char (const char_regex* r) // Assume already pooled. - : type (line_type::regex), regex (r) {} + // + // Steal two bits from the pointer to package line_char type. + // Assume (and statically assert) that char_regex address is a + // multiple of four. + // + : data_ (reinterpret_cast <std::uintptr_t> (r) | + static_cast <std::uintptr_t> (line_type::regex)) {} // Provide basic_regex with the ability to use line_char in a context // where a char value is expected (e.g., as a function argument). @@ -145,7 +171,7 @@ namespace build2 // operator char () const { - return type == line_type::special ? special : '\a'; // BELL. + return type () == line_type::special ? special () : '\a'; // BELL. } // Return true if the character is a syntax (special) one. @@ -160,8 +186,8 @@ namespace build2 explicit operator T () const { - assert (type == line_type::special); - return static_cast<T> (special); + assert (type () == line_type::special); + return static_cast<T> (special ()); } }; @@ -234,16 +260,16 @@ namespace build2 bool operator== (const line_char& l, const T& r) { - return - l.type == line_type::special && static_cast<T> (l.special) == r; + return l.type () == line_type::special && + static_cast<T> (l.special ()) == r; } template <typename T, typename = typename line_char_cmp<T>::type> bool operator== (const T& l, const line_char& r) { - return - r.type == line_type::special && static_cast<T> (r.special) == l; + return r.type () == line_type::special && + static_cast<T> (r.special ()) == l; } template <typename T, typename = typename line_char_cmp<T>::type> @@ -264,16 +290,16 @@ namespace build2 bool operator< (const line_char& l, const T& r) { - return - l.type == line_type::special && static_cast<T> (l.special) < r; + return l.type () == line_type::special && + static_cast<T> (l.special ()) < r; } template <typename T, typename = typename line_char_cmp<T>::type> bool operator< (const T& l, const line_char& r) { - return - r.type == line_type::special && l < static_cast<T> (r.special); + return r.type () == line_type::special && + l < static_cast<T> (r.special ()); } template <typename T, typename = typename line_char_cmp<T>::type> @@ -419,9 +445,10 @@ namespace std bool is (mask m, char_type c) const { - return m == (c.type == line_type::special && build2::digit (c.special) - ? digit - : 0); + return m == + (c.type () == line_type::special && build2::digit (c.special ()) + ? digit + : 0); } const char_type* @@ -454,7 +481,7 @@ namespace std char narrow (char_type c, char def) const { - return c.type == line_type::special ? c.special : def; + return c.type () == line_type::special ? c.special () : def; } const char_type* |