X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fvendor%2Ffmt%2Fargs.h;fp=src%2Fvendor%2Ffmt%2Fargs.h;h=9a8e4ed2cebb84c65b32633fcf82eb7cc6f92990;hp=0000000000000000000000000000000000000000;hb=05aa7e19ec97871aad18d7c9787c4c89611cd2cd;hpb=b3647fb885288c63d21478ea9a9c85685bc5c5f2 diff --git a/src/vendor/fmt/args.h b/src/vendor/fmt/args.h new file mode 100644 index 000000000..9a8e4ed2c --- /dev/null +++ b/src/vendor/fmt/args.h @@ -0,0 +1,234 @@ +// Formatting library for C++ - dynamic format arguments +// +// Copyright (c) 2012 - present, Victor Zverovich +// All rights reserved. +// +// For the license information refer to format.h. + +#ifndef FMT_ARGS_H_ +#define FMT_ARGS_H_ + +#include // std::reference_wrapper +#include // std::unique_ptr +#include + +#include "core.h" + +FMT_BEGIN_NAMESPACE + +namespace detail { + +template struct is_reference_wrapper : std::false_type {}; +template +struct is_reference_wrapper> : std::true_type {}; + +template const T& unwrap(const T& v) { return v; } +template const T& unwrap(const std::reference_wrapper& v) { + return static_cast(v); +} + +class dynamic_arg_list { + // Workaround for clang's -Wweak-vtables. Unlike for regular classes, for + // templates it doesn't complain about inability to deduce single translation + // unit for placing vtable. So storage_node_base is made a fake template. + template struct node { + virtual ~node() = default; + std::unique_ptr> next; + }; + + template struct typed_node : node<> { + T value; + + template + FMT_CONSTEXPR typed_node(const Arg& arg) : value(arg) {} + + template + FMT_CONSTEXPR typed_node(const basic_string_view& arg) + : value(arg.data(), arg.size()) {} + }; + + std::unique_ptr> head_; + + public: + template const T& push(const Arg& arg) { + auto new_node = std::unique_ptr>(new typed_node(arg)); + auto& value = new_node->value; + new_node->next = std::move(head_); + head_ = std::move(new_node); + return value; + } +}; +} // namespace detail + +/** + \rst + A dynamic version of `fmt::format_arg_store`. + It's equipped with a storage to potentially temporary objects which lifetimes + could be shorter than the format arguments object. + + It can be implicitly converted into `~fmt::basic_format_args` for passing + into type-erased formatting functions such as `~fmt::vformat`. + \endrst + */ +template +class dynamic_format_arg_store +#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409 + // Workaround a GCC template argument substitution bug. + : public basic_format_args +#endif +{ + private: + using char_type = typename Context::char_type; + + template struct need_copy { + static constexpr detail::type mapped_type = + detail::mapped_type_constant::value; + + enum { + value = !(detail::is_reference_wrapper::value || + std::is_same>::value || + std::is_same>::value || + (mapped_type != detail::type::cstring_type && + mapped_type != detail::type::string_type && + mapped_type != detail::type::custom_type)) + }; + }; + + template + using stored_type = conditional_t::value && + !has_formatter::value && + !detail::is_reference_wrapper::value, + std::basic_string, T>; + + // Storage of basic_format_arg must be contiguous. + std::vector> data_; + std::vector> named_info_; + + // Storage of arguments not fitting into basic_format_arg must grow + // without relocation because items in data_ refer to it. + detail::dynamic_arg_list dynamic_args_; + + friend class basic_format_args; + + unsigned long long get_types() const { + return detail::is_unpacked_bit | data_.size() | + (named_info_.empty() + ? 0ULL + : static_cast(detail::has_named_args_bit)); + } + + const basic_format_arg* data() const { + return named_info_.empty() ? data_.data() : data_.data() + 1; + } + + template void emplace_arg(const T& arg) { + data_.emplace_back(detail::make_arg(arg)); + } + + template + void emplace_arg(const detail::named_arg& arg) { + if (named_info_.empty()) { + constexpr const detail::named_arg_info* zero_ptr{nullptr}; + data_.insert(data_.begin(), {zero_ptr, 0}); + } + data_.emplace_back(detail::make_arg(detail::unwrap(arg.value))); + auto pop_one = [](std::vector>* data) { + data->pop_back(); + }; + std::unique_ptr>, decltype(pop_one)> + guard{&data_, pop_one}; + named_info_.push_back({arg.name, static_cast(data_.size() - 2u)}); + data_[0].value_.named_args = {named_info_.data(), named_info_.size()}; + guard.release(); + } + + public: + constexpr dynamic_format_arg_store() = default; + + /** + \rst + Adds an argument into the dynamic store for later passing to a formatting + function. + + Note that custom types and string types (but not string views) are copied + into the store dynamically allocating memory if necessary. + + **Example**:: + + fmt::dynamic_format_arg_store store; + store.push_back(42); + store.push_back("abc"); + store.push_back(1.5f); + std::string result = fmt::vformat("{} and {} and {}", store); + \endrst + */ + template void push_back(const T& arg) { + if (detail::const_check(need_copy::value)) + emplace_arg(dynamic_args_.push>(arg)); + else + emplace_arg(detail::unwrap(arg)); + } + + /** + \rst + Adds a reference to the argument into the dynamic store for later passing to + a formatting function. + + **Example**:: + + fmt::dynamic_format_arg_store store; + char band[] = "Rolling Stones"; + store.push_back(std::cref(band)); + band[9] = 'c'; // Changing str affects the output. + std::string result = fmt::vformat("{}", store); + // result == "Rolling Scones" + \endrst + */ + template void push_back(std::reference_wrapper arg) { + static_assert( + need_copy::value, + "objects of built-in types and string views are always copied"); + emplace_arg(arg.get()); + } + + /** + Adds named argument into the dynamic store for later passing to a formatting + function. ``std::reference_wrapper`` is supported to avoid copying of the + argument. The name is always copied into the store. + */ + template + void push_back(const detail::named_arg& arg) { + const char_type* arg_name = + dynamic_args_.push>(arg.name).c_str(); + if (detail::const_check(need_copy::value)) { + emplace_arg( + fmt::arg(arg_name, dynamic_args_.push>(arg.value))); + } else { + emplace_arg(fmt::arg(arg_name, arg.value)); + } + } + + /** Erase all elements from the store */ + void clear() { + data_.clear(); + named_info_.clear(); + dynamic_args_ = detail::dynamic_arg_list(); + } + + /** + \rst + Reserves space to store at least *new_cap* arguments including + *new_cap_named* named arguments. + \endrst + */ + void reserve(size_t new_cap, size_t new_cap_named) { + FMT_ASSERT(new_cap >= new_cap_named, + "Set of arguments includes set of named arguments"); + data_.reserve(new_cap); + named_info_.reserve(new_cap_named); + } +}; + +FMT_END_NAMESPACE + +#endif // FMT_ARGS_H_