Use explicit flag for the specific version of c++ wer'e targeting. #9231
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| @@ -19,7 +19,7 @@ AM_SILENT_RULES([yes]) | |||
| AC_CANONICAL_HOST | |||
| # Add some default CFLAGS and CXXFLAGS, can be appended to using the environment variables | |||
| CFLAGS="-g -O2 -Wall -Wextra -Wshadow -Wno-unused-parameter -Wmissing-declarations -Wredundant-decls $CFLAGS" | |||
| CXXFLAGS="-g -O2 -Wall -Wextra -Wshadow -Wno-unused-parameter -Wmissing-declarations -Wredundant-decls $CXXFLAGS" | |||
| CXXFLAGS="-std=c++11 -g -O2 -Wall -Wextra -Wshadow -Wno-unused-parameter -Wmissing-declarations -Wredundant-decls $CXXFLAGS" | |||
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isn't this what AX_CXX_COMPILE_STDCXX_11 is supposed to do/avoid? having both sounds bad to me, but i'm not an autoconf expert.
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Hmmm, lemme doublecheck the flags actually added.
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afaik, AX_CXX_COMPILE_STDCXX_11 checks if the flag is needed or not to support C++11 features. However, if your compiler default is to use C++14, it will happily run the compiler without -std=c++11, allowing the (accidental) use of newer C++ features
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Using the AX_CXX_COMPILE_STDCXX_11 we know the compiler supports c++11, but there are two issues:
- an extended mode might be used. This can be fixed by using
[noext]instead of[ext]. - Depending on the compiler, it might support a newer version of c++. One of the goals of this commit is to detect (accidental) use of features > c++11. Using
AX_CXX_COMPILE_STDCXX_11does not do that.
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Right. Maybe AX_CXX_COMPILE_STDCXX_11 can then just go away. (I hope compilers abort if they do not understand -std=c++11.
Short description
Been running this on my test OpenBSD/arm64 box for a while.
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