Coverage Report

Created: 2019-07-24 05:18

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/include/llvm/Support/Chrono.h
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//===- llvm/Support/Chrono.h - Utilities for Timing Manipulation-*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_SUPPORT_CHRONO_H
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#define LLVM_SUPPORT_CHRONO_H
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#include "llvm/Support/Compiler.h"
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#include "llvm/Support/FormatProviders.h"
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#include <chrono>
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#include <ctime>
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namespace llvm {
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class raw_ostream;
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namespace sys {
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/// A time point on the system clock. This is provided for two reasons:
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/// - to insulate us agains subtle differences in behavoir to differences in
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///   system clock precision (which is implementation-defined and differs between
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///   platforms).
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/// - to shorten the type name
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/// The default precision is nanoseconds. If need a specific precision specify
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/// it explicitly. If unsure, use the default. If you need a time point on a
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/// clock other than the system_clock, use std::chrono directly.
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template <typename D = std::chrono::nanoseconds>
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using TimePoint = std::chrono::time_point<std::chrono::system_clock, D>;
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/// Convert a TimePoint to std::time_t
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inline std::time_t toTimeT(TimePoint<> TP) {
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  using namespace std::chrono;
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  return system_clock::to_time_t(
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      time_point_cast<system_clock::time_point::duration>(TP));
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}
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/// Convert a std::time_t to a TimePoint
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inline TimePoint<std::chrono::seconds>
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toTimePoint(std::time_t T) {
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  using namespace std::chrono;
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  return time_point_cast<seconds>(system_clock::from_time_t(T));
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}
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/// Convert a std::time_t + nanoseconds to a TimePoint
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inline TimePoint<>
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toTimePoint(std::time_t T, uint32_t nsec) {
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  using namespace std::chrono;
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  return time_point_cast<nanoseconds>(system_clock::from_time_t(T))
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    + nanoseconds(nsec);
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}
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} // namespace sys
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raw_ostream &operator<<(raw_ostream &OS, sys::TimePoint<> TP);
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/// Format provider for TimePoint<>
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///
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/// The options string is a strftime format string, with extensions:
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///   - %L is millis: 000-999
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///   - %f is micros: 000000-999999
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///   - %N is nanos: 000000000 - 999999999
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///
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/// If no options are given, the default format is "%Y-%m-%d %H:%M:%S.%N".
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template <>
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struct format_provider<sys::TimePoint<>> {
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  static void format(const sys::TimePoint<> &TP, llvm::raw_ostream &OS,
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                     StringRef Style);
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};
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/// Implementation of format_provider<T> for duration types.
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///
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/// The options string of a duration  type has the grammar:
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///
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///   duration_options  ::= [unit][show_unit [number_options]]
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///   unit              ::= `h`|`m`|`s`|`ms|`us`|`ns`
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///   show_unit         ::= `+` | `-`
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///   number_options    ::= options string for a integral or floating point type
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///
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///   Examples
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///   =================================
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///   |  options  | Input | Output    |
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///   =================================
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///   | ""        | 1s    | 1 s       |
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///   | "ms"      | 1s    | 1000 ms   |
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///   | "ms-"     | 1s    | 1000      |
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///   | "ms-n"    | 1s    | 1,000     |
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///   | ""        | 1.0s  | 1.00 s    |
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///   =================================
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///
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///  If the unit of the duration type is not one of the units specified above,
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///  it is still possible to format it, provided you explicitly request a
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///  display unit or you request that the unit is not displayed.
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namespace detail {
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template <typename Period> struct unit { static const char value[]; };
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template <typename Period> const char unit<Period>::value[] = "";
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template <> struct unit<std::ratio<3600>> { static const char value[]; };
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template <> struct unit<std::ratio<60>> { static const char value[]; };
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template <> struct unit<std::ratio<1>> { static const char value[]; };
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template <> struct unit<std::milli> { static const char value[]; };
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template <> struct unit<std::micro> { static const char value[]; };
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template <> struct unit<std::nano> { static const char value[]; };
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} // namespace detail
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template <typename Rep, typename Period>
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struct format_provider<std::chrono::duration<Rep, Period>> {
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private:
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  typedef std::chrono::duration<Rep, Period> Dur;
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  typedef typename std::conditional<
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      std::chrono::treat_as_floating_point<Rep>::value, double, intmax_t>::type
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      InternalRep;
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  template <typename AsPeriod> static InternalRep getAs(const Dur &D) {
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    using namespace std::chrono;
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    return duration_cast<duration<InternalRep, AsPeriod>>(D).count();
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  }
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  static std::pair<InternalRep, StringRef> consumeUnit(StringRef &Style,
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                                                        const Dur &D) {
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    using namespace std::chrono;
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    if (Style.consume_front("ns"))
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      return {getAs<std::nano>(D), "ns"};
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    if (Style.consume_front("us"))
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      return {getAs<std::micro>(D), "us"};
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    if (Style.consume_front("ms"))
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      return {getAs<std::milli>(D), "ms"};
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    if (Style.consume_front("s"))
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      return {getAs<std::ratio<1>>(D), "s"};
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    if (Style.consume_front("m"))
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      return {getAs<std::ratio<60>>(D), "m"};
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    if (Style.consume_front("h"))
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      return {getAs<std::ratio<3600>>(D), "h"};
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    return {D.count(), detail::unit<Period>::value};
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  }
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  static bool consumeShowUnit(StringRef &Style) {
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    if (Style.empty())
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      return true;
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    if (Style.consume_front("-"))
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      return false;
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    if (Style.consume_front("+"))
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      return true;
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    assert(0 && "Unrecognised duration format");
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    return true;
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  }
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public:
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  static void format(const Dur &D, llvm::raw_ostream &Stream, StringRef Style) {
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    InternalRep count;
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    StringRef unit;
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    std::tie(count, unit) = consumeUnit(Style, D);
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    bool show_unit = consumeShowUnit(Style);
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    format_provider<InternalRep>::format(count, Stream, Style);
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    if (show_unit) {
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      assert(!unit.empty());
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      Stream << " " << unit;
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    }
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  }
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};
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} // namespace llvm
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#endif // LLVM_SUPPORT_CHRONO_H