【发布时间】：2017-07-31 22:28:41
【问题描述】：
我在使用 cmake 和 Visual Studio 14 2015 从官方源文件构建 LLVM 时遇到多个错误，并且无法弄清楚为什么会发生这种情况，这些错误出现的原因是什么？
D:\LLVM\build\llvm\include\llvm/Support/AlignOf.h(57)： 错误 C2988：无法识别的模板声明/定义 [D:\LLVM\build\build\lib\System\LLVMSystem.vcxproj] D:\LLVM\build\llvm\include\llvm/Support/AlignOf.h(57): 错误 C2059：语法错误：'alignof' [D:\LLVM\build\build\lib\System\LLVMSystem.vcxproj] D:\LLVM\build\llvm\include\llvm/Support/AlignOf.h(59)： 错误 C2143：语法错误：缺少“；”前 '}' [D:\LLVM\build\build\lib\System\LLVMSystem.vcxproj]
这是 AlignOf.h 文件中的代码：
#ifndef LLVM_SUPPORT_ALIGNOF_H
#define LLVM_SUPPORT_ALIGNOF_H
namespace llvm {
template <typename T>
struct AlignmentCalcImpl {
char x;
T t;
private:
AlignmentCalcImpl() {} // Never instantiate.
};
/// AlignOf - A templated class that contains an enum value representing
/// the alignment of the template argument. For example,
/// AlignOf<int>::Alignment represents the alignment of type "int". The
/// alignment calculated is the minimum alignment, and not necessarily
/// the "desired" alignment returned by GCC's __alignof__ (for example). Note
/// that because the alignment is an enum value, it can be used as a
/// compile-time constant (e.g., for template instantiation).
template <typename T>
struct AlignOf {
enum { Alignment =
static_cast<unsigned int>(sizeof(AlignmentCalcImpl<T>) - sizeof(T)) };
enum { Alignment_GreaterEqual_2Bytes = Alignment >= 2 ? 1 : 0 };
enum { Alignment_GreaterEqual_4Bytes = Alignment >= 4 ? 1 : 0 };
enum { Alignment_GreaterEqual_8Bytes = Alignment >= 8 ? 1 : 0 };
enum { Alignment_GreaterEqual_16Bytes = Alignment >= 16 ? 1 : 0 };
enum { Alignment_LessEqual_2Bytes = Alignment <= 2 ? 1 : 0 };
enum { Alignment_LessEqual_4Bytes = Alignment <= 4 ? 1 : 0 };
enum { Alignment_LessEqual_8Bytes = Alignment <= 8 ? 1 : 0 };
enum { Alignment_LessEqual_16Bytes = Alignment <= 16 ? 1 : 0 };
};
/// alignof - A templated function that returns the mininum alignment of
/// of a type. This provides no extra functionality beyond the AlignOf
/// class besides some cosmetic cleanliness. Example usage:
/// alignof<int>() returns the alignment of an int.
template <typename T>
static inline unsigned alignof() { return AlignOf<T>::Alignment; }
} // end namespace llvm
#endif
【问题讨论】：
-
你甚至可以使用 microsoft cl.exe 编译器构建 llvm 吗？
-
在构建时，我正在遵循官方 llvm 指南“使用 CMake 构建 LLVM”llvm.org/docs/CMake.html，并在 AlignOf.h 中获得“无法识别的模板声明”，任何线索为什么会出现问题？跨度>