Try removing attempt to set the C++ standard #1464
Conversation
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No, this is wrong. |
it's just a draft because i want to see what happens... the compiler used should be free to set it's standard. we already had a fallback to c++0x so the only issue i think would be if someone tries to use a compiler that doesn't support c++11. if we want to require that then setting |
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There is absolutely no requirement that a supported compiler version actually happens |
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first test complete: OSX falls back too far beyond C++11. next up: setting the standard. |
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https://cmake.org/cmake/help/latest/policy/CMP0067.html might be relevant. |
nice :) |
| @@ -137,6 +138,9 @@ if (BENCHMARK_BUILD_32_BITS) | |||
| add_required_cxx_compiler_flag(-m32) | |||
| endif() | |||
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| set(CMAKE_CXX_STANDARD 11) | |||
| set(CMAKE_CXX_STANDARD_REQUIRED ON) | |||
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Probably also want CMAKE_CXX_EXTENSIONS OFF
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yeah.. i'm also eyeing up the check where we:
set(EXTRA_CXX_FLAGS "")
if (WIN32 AND "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
# Clang on Windows fails to compile the regex feature check under C++11
set(EXTRA_CXX_FLAGS "-DCMAKE_CXX_STANDARD=14")
endif()
and wondering how that will end up interacting with this change.
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yes FWIW we need this check for clang on windows.
cmake 3.8+ only .. ubuntu 16.04 is still on 3.5.1: https://launchpad.net/ubuntu/xenial/+source/cmake |
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so our older platform support requires explicit until we can drop older platforms, i don't think we can embrace updated cmake norms... any other ideas, @LebedevRI ? |
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cmake 3.5.1 sounds really ancient. |
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ubuntu bionic (the oldest LTS ubuntu we support) is 3.10.2 (https://packages.ubuntu.com/bionic/cmake) so i think we can get past 3.8. it might mean dropping the 14.04 and 16.04 bots but they are really old at this point and we do have a policy on dependencies for a reason. |
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Sounds reasonable? |
| @@ -137,6 +139,10 @@ if (BENCHMARK_BUILD_32_BITS) | |||
| add_required_cxx_compiler_flag(-m32) | |||
| endif() | |||
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| set(CMAKE_CXX_STANDARD 11) | |||
| set(CMAKE_CXX_STANDARD_REQUIRED ON) | |||
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This is not meaningful. MSVC, for instance, does not provide exclusive C++11 support, only C++14 and later: https://docs.microsoft.com/en-us/cpp/build/reference/std-specify-language-standard-version?view=msvc-170. CMake will probably decay to the newer standard anyway.
seems like we might just have had our hand forced... |
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@dmah42 what's the status here? |
i don't remember where i got to. let me see if i can resurrect it. |
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it builds and passes tests but I'm not sure it's the right thing to do. I would appreciate an ack. |
Given that we don't want to just happen to build under whatever the standard is default |
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merged.. now let's see if anyone finds an issue on any unusual platforms with it. |
Fixes #1460 #1462
Let's see what the buildbots make of this.