chromium/crc32c-string-view-check.patch

   1 From d0f929a5db87cb34d03afb0d8e8bfc95b8f786e3 Mon Sep 17 00:00:00 2001
   2 From: Victor Costan <costan@gmail.com>
   3 Date: Mon, 11 Sep 2017 13:18:27 -0700
   4 Subject: [PATCH] More conservative check for <string_view> availability. (#4)
   5
   6 has_include(<string_view>) does not imply that the header can be
   7 included and will work. The assumption fails on MSVC and libc++ [1, 2].
   8 Conversely, checking that __cplusplus > 201402L is not sufficient on its
   9 own either, as the toolchain on Mac OS 10.12 passes that check but does
  10 not contain a <string_view> header.
  11
  12 [1] https://crbug.com/759349
  13 [2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79433
  14 ---
  15  include/crc32c/crc32c.h | 10 +++-------
  16  src/crc32c_unittest.cc  |  6 ++----
  17  2 files changed, 5 insertions(+), 11 deletions(-)
  18
  19 diff --git a/include/crc32c/crc32c.h b/include/crc32c/crc32c.h
  20 index 9f1973a..8ecab0d 100644
  21 --- a/include/crc32c/crc32c.h
  22 +++ b/include/crc32c/crc32c.h
  23 @@ -33,22 +33,18 @@ inline uint32_t Crc32c(const std::string& string) {
  24                  string.size());
  25  }
  26
  27 -#if defined(__has_include)
  28 +#if __cplusplus > 201402L
  29  #if __has_include(<string_view>)
  30 -// Visual Studio provides a <string_view> header even in C++11 mode. When
  31 -// included, the header issues an #error. (C1189)
  32 -#if !defined(_MSC_VER) || __cplusplus >= 201703L
  33  #include <string_view>
  34
  35 -// Comptues the CRC32C of the bytes in the string_view.
  36 +// Computes the CRC32C of the bytes in the string_view.
  37  inline uint32_t Crc32c(const std::string_view& string_view) {
  38    return Crc32c(reinterpret_cast<const uint8_t*>(string_view.data()),
  39                  string_view.size());
  40  }
  41
  42 -#endif  // !defined(_MSC_VER) || __cplusplus >= 201703L
  43  #endif  // __has_include(<string_view>)
  44 -#endif  // defined(__has_include)
  45 +#endif  // __cplusplus > 201402L
  46
  47  }  // namespace crc32c
  48
  49 diff --git a/src/crc32c_unittest.cc b/src/crc32c_unittest.cc
  50 index 7a9c765..69babb3 100644
  51 --- a/src/crc32c_unittest.cc
  52 +++ b/src/crc32c_unittest.cc
  53 @@ -95,9 +95,8 @@ TEST(CRC32CTest, Crc32cStdString) {
  54    EXPECT_EQ(static_cast<uint32_t>(0x113fdb5c), crc32c::Crc32c(buf));
  55  }
  56
  57 -#if defined(__has_include)
  58 +#if __cplusplus > 201402L
  59  #if __has_include(<string_view>)
  60 -#if !defined(_MSC_VER) || __cplusplus >= 201703L
  61
  62  TEST(CRC32CTest, Crc32cStdStringView) {
  63    uint8_t buf[32];
  64 @@ -118,9 +117,8 @@ TEST(CRC32CTest, Crc32cStdStringView) {
  65    EXPECT_EQ(static_cast<uint32_t>(0x113fdb5c), crc32c::Crc32c(view));
  66  }
  67
  68 -#endif  // !defined(_MSC_VER) || __cplusplus >= 201703L
  69  #endif  // __has_include(<string_view>)
  70 -#endif  // defined(__has_include)
  71 +#endif  // __cplusplus > 201402L
  72
  73  #define TESTED_EXTEND Extend
  74  #include "./crc32c_extend_unittests.h"