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author | Reid Kleckner <reid@kleckner.net> | 2013-09-23 23:26:57 +0000 |
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committer | Reid Kleckner <reid@kleckner.net> | 2013-09-23 23:26:57 +0000 |
commit | 118a0659ab8a4d0e0af343b88e5fa71a5c1eb6a6 (patch) | |
tree | 0ccf13d04a66fc600e3ecc221f91bc4ced150676 /include/llvm/Support/Compiler.h | |
parent | 5a63474e2d4c797ca8245edae4064f17b47df3ee (diff) | |
download | external_llvm-118a0659ab8a4d0e0af343b88e5fa71a5c1eb6a6.zip external_llvm-118a0659ab8a4d0e0af343b88e5fa71a5c1eb6a6.tar.gz external_llvm-118a0659ab8a4d0e0af343b88e5fa71a5c1eb6a6.tar.bz2 |
Explicitly request unsigned enum types when desired
The underlying type of all plain enums in MSVC is 'int', even if the
enumerator contains large 32-bit unsigned values or values greater than
UINT_MAX. The only way to get a large or unsigned enum type is to
request it explicitly with the C++11 strong enum types feature.
However, since LLVM isn't C++11 yet, I had to add a conditional
LLVM_ENUM_INT_TYPE to Compiler.h to control its usage.
The motivating true positive for this change is compiling PointerIntPair
with MSVC for win64. The PointerIntMask value is supposed to be pointer
sized value of all ones with some low zeros. Instead, it's truncated to
32-bits! We are only saved later because it is sign extended back in
the AND with int64_t, and we happen to want all ones.
This silences lots of -Wmicrosoft warnings during a clang self-host
targeting Windows.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191241 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/llvm/Support/Compiler.h')
-rw-r--r-- | include/llvm/Support/Compiler.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/llvm/Support/Compiler.h b/include/llvm/Support/Compiler.h index c32a485..13920fc 100644 --- a/include/llvm/Support/Compiler.h +++ b/include/llvm/Support/Compiler.h @@ -391,4 +391,16 @@ # define LLVM_STATIC_ASSERT(expr, msg) #endif +/// \macro LLVM_ENUM_INT_TYPE +/// \brief Expands to colon followed by the given integral type on compilers +/// which support C++11 strong enums. This can be used to make enums unsigned +/// with MSVC. +#if __has_feature(cxx_strong_enums) +# define LLVM_ENUM_INT_TYPE(intty) : intty +#elif defined(_MSC_VER) && _MSC_VER >= 1600 // Added in MSVC 2010. +# define LLVM_ENUM_INT_TYPE(intty) : intty +#else +# define LLVM_ENUM_INT_TYPE(intty) +#endif + #endif |