--- /dev/null
+// Formatting library for C++ - experimental format string compilation
+//
+// Copyright (c) 2012 - present, Victor Zverovich and fmt contributors
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_COMPILE_H_
+#define FMT_COMPILE_H_
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+// An output iterator that counts the number of objects written to it and
+// discards them.
+class counting_iterator {
+ private:
+ size_t count_;
+
+ public:
+ using iterator_category = std::output_iterator_tag;
+ using difference_type = std::ptrdiff_t;
+ using pointer = void;
+ using reference = void;
+ using _Unchecked_type = counting_iterator; // Mark iterator as checked.
+
+ struct value_type {
+ template <typename T> void operator=(const T&) {}
+ };
+
+ counting_iterator() : count_(0) {}
+
+ size_t count() const { return count_; }
+
+ counting_iterator& operator++() {
+ ++count_;
+ return *this;
+ }
+ counting_iterator operator++(int) {
+ auto it = *this;
+ ++*this;
+ return it;
+ }
+
+ friend counting_iterator operator+(counting_iterator it, difference_type n) {
+ it.count_ += static_cast<size_t>(n);
+ return it;
+ }
+
+ value_type operator*() const { return {}; }
+};
+
+template <typename Char, typename InputIt>
+inline counting_iterator copy_str(InputIt begin, InputIt end,
+ counting_iterator it) {
+ return it + (end - begin);
+}
+
+template <typename OutputIt> class truncating_iterator_base {
+ protected:
+ OutputIt out_;
+ size_t limit_;
+ size_t count_ = 0;
+
+ truncating_iterator_base() : out_(), limit_(0) {}
+
+ truncating_iterator_base(OutputIt out, size_t limit)
+ : out_(out), limit_(limit) {}
+
+ public:
+ using iterator_category = std::output_iterator_tag;
+ using value_type = typename std::iterator_traits<OutputIt>::value_type;
+ using difference_type = std::ptrdiff_t;
+ using pointer = void;
+ using reference = void;
+ using _Unchecked_type =
+ truncating_iterator_base; // Mark iterator as checked.
+
+ OutputIt base() const { return out_; }
+ size_t count() const { return count_; }
+};
+
+// An output iterator that truncates the output and counts the number of objects
+// written to it.
+template <typename OutputIt,
+ typename Enable = typename std::is_void<
+ typename std::iterator_traits<OutputIt>::value_type>::type>
+class truncating_iterator;
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::false_type>
+ : public truncating_iterator_base<OutputIt> {
+ mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;
+
+ public:
+ using value_type = typename truncating_iterator_base<OutputIt>::value_type;
+
+ truncating_iterator() = default;
+
+ truncating_iterator(OutputIt out, size_t limit)
+ : truncating_iterator_base<OutputIt>(out, limit) {}
+
+ truncating_iterator& operator++() {
+ if (this->count_++ < this->limit_) ++this->out_;
+ return *this;
+ }
+
+ truncating_iterator operator++(int) {
+ auto it = *this;
+ ++*this;
+ return it;
+ }
+
+ value_type& operator*() const {
+ return this->count_ < this->limit_ ? *this->out_ : blackhole_;
+ }
+};
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::true_type>
+ : public truncating_iterator_base<OutputIt> {
+ public:
+ truncating_iterator() = default;
+
+ truncating_iterator(OutputIt out, size_t limit)
+ : truncating_iterator_base<OutputIt>(out, limit) {}
+
+ template <typename T> truncating_iterator& operator=(T val) {
+ if (this->count_++ < this->limit_) *this->out_++ = val;
+ return *this;
+ }
+
+ truncating_iterator& operator++() { return *this; }
+ truncating_iterator& operator++(int) { return *this; }
+ truncating_iterator& operator*() { return *this; }
+};
+
+// A compile-time string which is compiled into fast formatting code.
+class compiled_string {};
+
+template <typename S>
+struct is_compiled_string : std::is_base_of<compiled_string, S> {};
+
+/**
+ \rst
+ Converts a string literal *s* into a format string that will be parsed at
+ compile time and converted into efficient formatting code. Requires C++17
+ ``constexpr if`` compiler support.
+
+ **Example**::
+
+ // Converts 42 into std::string using the most efficient method and no
+ // runtime format string processing.
+ std::string s = fmt::format(FMT_COMPILE("{}"), 42);
+ \endrst
+ */
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+# define FMT_COMPILE(s) \
+ FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit)
+#else
+# define FMT_COMPILE(s) FMT_STRING(s)
+#endif
+
+#if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+template <typename Char, size_t N,
+ fmt::detail_exported::fixed_string<Char, N> Str>
+struct udl_compiled_string : compiled_string {
+ using char_type = Char;
+ constexpr operator basic_string_view<char_type>() const {
+ return {Str.data, N - 1};
+ }
+};
+#endif
+
+template <typename T, typename... Tail>
+const T& first(const T& value, const Tail&...) {
+ return value;
+}
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+template <typename... Args> struct type_list {};
+
+// Returns a reference to the argument at index N from [first, rest...].
+template <int N, typename T, typename... Args>
+constexpr const auto& get([[maybe_unused]] const T& first,
+ [[maybe_unused]] const Args&... rest) {
+ static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
+ if constexpr (N == 0)
+ return first;
+ else
+ return detail::get<N - 1>(rest...);
+}
+
+template <typename Char, typename... Args>
+constexpr int get_arg_index_by_name(basic_string_view<Char> name,
+ type_list<Args...>) {
+ return get_arg_index_by_name<Args...>(name);
+}
+
+template <int N, typename> struct get_type_impl;
+
+template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> {
+ using type =
+ remove_cvref_t<decltype(detail::get<N>(std::declval<Args>()...))>;
+};
+
+template <int N, typename T>
+using get_type = typename get_type_impl<N, T>::type;
+
+template <typename T> struct is_compiled_format : std::false_type {};
+
+template <typename Char> struct text {
+ basic_string_view<Char> data;
+ using char_type = Char;
+
+ template <typename OutputIt, typename... Args>
+ constexpr OutputIt format(OutputIt out, const Args&...) const {
+ return write<Char>(out, data);
+ }
+};
+
+template <typename Char>
+struct is_compiled_format<text<Char>> : std::true_type {};
+
+template <typename Char>
+constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos,
+ size_t size) {
+ return {{&s[pos], size}};
+}
+
+template <typename Char> struct code_unit {
+ Char value;
+ using char_type = Char;
+
+ template <typename OutputIt, typename... Args>
+ constexpr OutputIt format(OutputIt out, const Args&...) const {
+ return write<Char>(out, value);
+ }
+};
+
+// This ensures that the argument type is convertible to `const T&`.
+template <typename T, int N, typename... Args>
+constexpr const T& get_arg_checked(const Args&... args) {
+ const auto& arg = detail::get<N>(args...);
+ if constexpr (detail::is_named_arg<remove_cvref_t<decltype(arg)>>()) {
+ return arg.value;
+ } else {
+ return arg;
+ }
+}
+
+template <typename Char>
+struct is_compiled_format<code_unit<Char>> : std::true_type {};
+
+// A replacement field that refers to argument N.
+template <typename Char, typename T, int N> struct field {
+ using char_type = Char;
+
+ template <typename OutputIt, typename... Args>
+ constexpr OutputIt format(OutputIt out, const Args&... args) const {
+ return write<Char>(out, get_arg_checked<T, N>(args...));
+ }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<field<Char, T, N>> : std::true_type {};
+
+// A replacement field that refers to argument with name.
+template <typename Char> struct runtime_named_field {
+ using char_type = Char;
+ basic_string_view<Char> name;
+
+ template <typename OutputIt, typename T>
+ constexpr static bool try_format_argument(
+ OutputIt& out,
+ // [[maybe_unused]] due to unused-but-set-parameter warning in GCC 7,8,9
+ [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) {
+ if constexpr (is_named_arg<typename std::remove_cv<T>::type>::value) {
+ if (arg_name == arg.name) {
+ out = write<Char>(out, arg.value);
+ return true;
+ }
+ }
+ return false;
+ }
+
+ template <typename OutputIt, typename... Args>
+ constexpr OutputIt format(OutputIt out, const Args&... args) const {
+ bool found = (try_format_argument(out, name, args) || ...);
+ if (!found) {
+ FMT_THROW(format_error("argument with specified name is not found"));
+ }
+ return out;
+ }
+};
+
+template <typename Char>
+struct is_compiled_format<runtime_named_field<Char>> : std::true_type {};
+
+// A replacement field that refers to argument N and has format specifiers.
+template <typename Char, typename T, int N> struct spec_field {
+ using char_type = Char;
+ formatter<T, Char> fmt;
+
+ template <typename OutputIt, typename... Args>
+ constexpr FMT_INLINE OutputIt format(OutputIt out,
+ const Args&... args) const {
+ const auto& vargs =
+ fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...);
+ basic_format_context<OutputIt, Char> ctx(out, vargs);
+ return fmt.format(get_arg_checked<T, N>(args...), ctx);
+ }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<spec_field<Char, T, N>> : std::true_type {};
+
+template <typename L, typename R> struct concat {
+ L lhs;
+ R rhs;
+ using char_type = typename L::char_type;
+
+ template <typename OutputIt, typename... Args>
+ constexpr OutputIt format(OutputIt out, const Args&... args) const {
+ out = lhs.format(out, args...);
+ return rhs.format(out, args...);
+ }
+};
+
+template <typename L, typename R>
+struct is_compiled_format<concat<L, R>> : std::true_type {};
+
+template <typename L, typename R>
+constexpr concat<L, R> make_concat(L lhs, R rhs) {
+ return {lhs, rhs};
+}
+
+struct unknown_format {};
+
+template <typename Char>
+constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
+ for (size_t size = str.size(); pos != size; ++pos) {
+ if (str[pos] == '{' || str[pos] == '}') break;
+ }
+ return pos;
+}
+
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str);
+
+template <typename Args, size_t POS, int ID, typename T, typename S>
+constexpr auto parse_tail(T head, S format_str) {
+ if constexpr (POS !=
+ basic_string_view<typename S::char_type>(format_str).size()) {
+ constexpr auto tail = compile_format_string<Args, POS, ID>(format_str);
+ if constexpr (std::is_same<remove_cvref_t<decltype(tail)>,
+ unknown_format>())
+ return tail;
+ else
+ return make_concat(head, tail);
+ } else {
+ return head;
+ }
+}
+
+template <typename T, typename Char> struct parse_specs_result {
+ formatter<T, Char> fmt;
+ size_t end;
+ int next_arg_id;
+};
+
+constexpr int manual_indexing_id = -1;
+
+template <typename T, typename Char>
+constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
+ size_t pos, int next_arg_id) {
+ str.remove_prefix(pos);
+ auto ctx = basic_format_parse_context<Char>(str, {}, next_arg_id);
+ auto f = formatter<T, Char>();
+ auto end = f.parse(ctx);
+ return {f, pos + fmt::detail::to_unsigned(end - str.data()) + 1,
+ next_arg_id == 0 ? manual_indexing_id : ctx.next_arg_id()};
+}
+
+template <typename Char> struct arg_id_handler {
+ arg_ref<Char> arg_id;
+
+ constexpr int operator()() {
+ FMT_ASSERT(false, "handler cannot be used with automatic indexing");
+ return 0;
+ }
+ constexpr int operator()(int id) {
+ arg_id = arg_ref<Char>(id);
+ return 0;
+ }
+ constexpr int operator()(basic_string_view<Char> id) {
+ arg_id = arg_ref<Char>(id);
+ return 0;
+ }
+
+ constexpr void on_error(const char* message) {
+ FMT_THROW(format_error(message));
+ }
+};
+
+template <typename Char> struct parse_arg_id_result {
+ arg_ref<Char> arg_id;
+ const Char* arg_id_end;
+};
+
+template <int ID, typename Char>
+constexpr auto parse_arg_id(const Char* begin, const Char* end) {
+ auto handler = arg_id_handler<Char>{arg_ref<Char>{}};
+ auto arg_id_end = parse_arg_id(begin, end, handler);
+ return parse_arg_id_result<Char>{handler.arg_id, arg_id_end};
+}
+
+template <typename T, typename Enable = void> struct field_type {
+ using type = remove_cvref_t<T>;
+};
+
+template <typename T>
+struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> {
+ using type = remove_cvref_t<decltype(T::value)>;
+};
+
+template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID,
+ typename S>
+constexpr auto parse_replacement_field_then_tail(S format_str) {
+ using char_type = typename S::char_type;
+ constexpr auto str = basic_string_view<char_type>(format_str);
+ constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type();
+ if constexpr (c == '}') {
+ return parse_tail<Args, END_POS + 1, NEXT_ID>(
+ field<char_type, typename field_type<T>::type, ARG_INDEX>(),
+ format_str);
+ } else if constexpr (c == ':') {
+ constexpr auto result = parse_specs<typename field_type<T>::type>(
+ str, END_POS + 1, NEXT_ID == manual_indexing_id ? 0 : NEXT_ID);
+ return parse_tail<Args, result.end, result.next_arg_id>(
+ spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{
+ result.fmt},
+ format_str);
+ }
+}
+
+// Compiles a non-empty format string and returns the compiled representation
+// or unknown_format() on unrecognized input.
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str) {
+ using char_type = typename S::char_type;
+ constexpr auto str = basic_string_view<char_type>(format_str);
+ if constexpr (str[POS] == '{') {
+ if constexpr (POS + 1 == str.size())
+ FMT_THROW(format_error("unmatched '{' in format string"));
+ if constexpr (str[POS + 1] == '{') {
+ return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+ } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') {
+ static_assert(ID != manual_indexing_id,
+ "cannot switch from manual to automatic argument indexing");
+ constexpr auto next_id =
+ ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+ return parse_replacement_field_then_tail<get_type<ID, Args>, Args,
+ POS + 1, ID, next_id>(
+ format_str);
+ } else {
+ constexpr auto arg_id_result =
+ parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size());
+ constexpr auto arg_id_end_pos = arg_id_result.arg_id_end - str.data();
+ constexpr char_type c =
+ arg_id_end_pos != str.size() ? str[arg_id_end_pos] : char_type();
+ static_assert(c == '}' || c == ':', "missing '}' in format string");
+ if constexpr (arg_id_result.arg_id.kind == arg_id_kind::index) {
+ static_assert(
+ ID == manual_indexing_id || ID == 0,
+ "cannot switch from automatic to manual argument indexing");
+ constexpr auto arg_index = arg_id_result.arg_id.val.index;
+ return parse_replacement_field_then_tail<get_type<arg_index, Args>,
+ Args, arg_id_end_pos,
+ arg_index, manual_indexing_id>(
+ format_str);
+ } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) {
+ constexpr auto arg_index =
+ get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{});
+ if constexpr (arg_index != invalid_arg_index) {
+ constexpr auto next_id =
+ ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+ return parse_replacement_field_then_tail<
+ decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos,
+ arg_index, next_id>(format_str);
+ } else {
+ if constexpr (c == '}') {
+ return parse_tail<Args, arg_id_end_pos + 1, ID>(
+ runtime_named_field<char_type>{arg_id_result.arg_id.val.name},
+ format_str);
+ } else if constexpr (c == ':') {
+ return unknown_format(); // no type info for specs parsing
+ }
+ }
+ }
+ }
+ } else if constexpr (str[POS] == '}') {
+ if constexpr (POS + 1 == str.size())
+ FMT_THROW(format_error("unmatched '}' in format string"));
+ return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+ } else {
+ constexpr auto end = parse_text(str, POS + 1);
+ if constexpr (end - POS > 1) {
+ return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+ format_str);
+ } else {
+ return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]},
+ format_str);
+ }
+ }
+}
+
+template <typename... Args, typename S,
+ FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+constexpr auto compile(S format_str) {
+ constexpr auto str = basic_string_view<typename S::char_type>(format_str);
+ if constexpr (str.size() == 0) {
+ return detail::make_text(str, 0, 0);
+ } else {
+ constexpr auto result =
+ detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
+ format_str);
+ return result;
+ }
+}
+#endif // defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+} // namespace detail
+
+FMT_MODULE_EXPORT_BEGIN
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+
+template <typename CompiledFormat, typename... Args,
+ typename Char = typename CompiledFormat::char_type,
+ FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
+FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf,
+ const Args&... args) {
+ auto s = std::basic_string<Char>();
+ cf.format(std::back_inserter(s), args...);
+ return s;
+}
+
+template <typename OutputIt, typename CompiledFormat, typename... Args,
+ FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
+constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+ const Args&... args) {
+ return cf.format(out, args...);
+}
+
+template <typename S, typename... Args,
+ FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
+ Args&&... args) {
+ if constexpr (std::is_same<typename S::char_type, char>::value) {
+ constexpr auto str = basic_string_view<typename S::char_type>(S());
+ if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}') {
+ const auto& first = detail::first(args...);
+ if constexpr (detail::is_named_arg<
+ remove_cvref_t<decltype(first)>>::value) {
+ return fmt::to_string(first.value);
+ } else {
+ return fmt::to_string(first);
+ }
+ }
+ }
+ constexpr auto compiled = detail::compile<Args...>(S());
+ if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+ detail::unknown_format>()) {
+ return format(static_cast<basic_string_view<typename S::char_type>>(S()),
+ std::forward<Args>(args)...);
+ } else {
+ return format(compiled, std::forward<Args>(args)...);
+ }
+}
+
+template <typename OutputIt, typename S, typename... Args,
+ FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) {
+ constexpr auto compiled = detail::compile<Args...>(S());
+ if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+ detail::unknown_format>()) {
+ return format_to(out,
+ static_cast<basic_string_view<typename S::char_type>>(S()),
+ std::forward<Args>(args)...);
+ } else {
+ return format_to(out, compiled, std::forward<Args>(args)...);
+ }
+}
+#endif
+
+template <typename OutputIt, typename S, typename... Args,
+ FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
+ const S& format_str, Args&&... args) {
+ auto it = format_to(detail::truncating_iterator<OutputIt>(out, n), format_str,
+ std::forward<Args>(args)...);
+ return {it.base(), it.count()};
+}
+
+template <typename S, typename... Args,
+ FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+size_t formatted_size(const S& format_str, const Args&... args) {
+ return format_to(detail::counting_iterator(), format_str, args...).count();
+}
+
+template <typename S, typename... Args,
+ FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(std::FILE* f, const S& format_str, const Args&... args) {
+ memory_buffer buffer;
+ format_to(std::back_inserter(buffer), format_str, args...);
+ detail::print(f, {buffer.data(), buffer.size()});
+}
+
+template <typename S, typename... Args,
+ FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(const S& format_str, const Args&... args) {
+ print(stdout, format_str, args...);
+}
+
+#if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+inline namespace literals {
+template <detail_exported::fixed_string Str>
+constexpr detail::udl_compiled_string<
+ remove_cvref_t<decltype(Str.data[0])>,
+ sizeof(Str.data) / sizeof(decltype(Str.data[0])), Str>
+operator""_cf() {
+ return {};
+}
+} // namespace literals
+#endif
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif // FMT_COMPILE_H_
projects / lttng-tools.git / blobdiff