Cmake无法识别MSVC编译器。

Question

这是我第一次遇到这个错误。

我正在尝试克隆openvr并运行hello opengl示例，按照他们的说明进行操作：

cd samples
mkdir build
cd build
cmake .. -G "Visual Studio 14 2015 Win64" -DCMAKE_PREFIX_PATH=C:/Qt/5.6/msvc2013_64/lib/cmake

我能理解：

$ cmake .. -G "Visual Studio 14 2015 Win64" -DCMAKE_PREFIX_PATH=C:/Qt/5.6/msvc20                                                                       13_64/lib/cmake
-- The C compiler identification is MSVC 19.0.24215.1
-- The CXX compiler identification is MSVC 19.0.24215.1
-- Check for working C compiler using: Visual Studio 14 2015 Win64
-- Check for working C compiler using: Visual Studio 14 2015 Win64 -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler using: Visual Studio 14 2015 Win64
-- Check for working CXX compiler using: Visual Studio 14 2015 Win64 -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Compilation set for 64bits architectures.
CMake Warning at CMakeLists.txt:40 (message):
  SDL x64 runtime binaries not provided on Windows.


CMake Error at CMakeLists.txt:98 (message):
  Unsupported compiler.


-- Configuring incomplete, errors occurred!
See also "C:/Users/GBarbieri/Documents/Visual Studio 2015/Projects/openvr/sample                                                                       s/build/CMakeFiles/CMakeOutput.log".

如果我去检查第98行：

if(   (${CMAKE_CXX_COMPILER_ID} MATCHES "GNU")
   OR (${CMAKE_CXX_COMPILER_ID} MATCHES "Clang"))
  # Better to use the prebuilt GNU preprocessor define __GNUC__,
  # kept for legacy reason with the sample code.
  add_definitions(-DGNUC)

  set(CMAKE_CXX_FLAGS         "${CMAKE_CXX_FLAGS} -std=c++11 -include ${SHARED_SRC_DIR}/compat.h")
  set(CMAKE_CXX_FLAGS_DEBUG   "${CMAKE_CXX_FLAGS_DEBUG} -Wall -Wextra -pedantic -g")
  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2")

  # Handles x86 compilation support on x64 arch.
  if(${PLATFORM} MATCHES 32)
    set(CMAKE_CXX_FLAGS        "${CMAKE_CXX_FLAGS} -m32")
    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
  endif()
elseif(${CMAKE_CXX_COMPILER_ID} MATCHES "MSVC")
  set(CMAKE_CXX_FLAGS         "${CMAKE_CXX_FLAGS} /Za")
  set(CMAKE_CXX_FLAGS_DEBUG   "${CMAKE_CXX_FLAGS_DEBUG} /w2 /DEBUG")
  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /MP /INCREMENTAL:NO")
else()
  message(FATAL_ERROR "Unsupported compiler. ")    // line 98
endif()

看起来无法匹配"MSVC".. 让我试一下，在这段代码之前添加：

message("${CMAKE_CXX_COMPILER_ID}")
if(${CMAKE_CXX_COMPILER_ID} MATCHES "MSVC")
    message("match")
else()
    message("!match")
endif()

然后它返回：

MSVC
!match
CMake Error at CMakeLists.txt:104 (message):
  Unsupported compiler.

什么？

你们能发现有什么问题吗，伙计们？

- elect

---

难道不应该只是：if(MSVC)？ - roalz

你试过这个吗？if(CMAKE_CXX_COMPILER_ID MATCHES "MSVC") - roalz

可以的。我会修改 CMakeList.txt 文件。 - elect

你是否拥有 CMake 版本大于 3.1？ - pSoLT

无论它是如何工作的，我现在正在处理qt。 - elect

Answer 1

好的，正如我在评论中尝试的那样，正确的答案是使用：

if(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")

替代

if(${CMAKE_CXX_COMPILER_ID} MATCHES "MSVC")

- roalz

---

如果您对第一个工作和第二个不工作的细节感兴趣，请参见设置和使用变量的CMake语法是什么？。有趣的是，我在那里使用了完全相同的MSVC示例来演示变量命名解析问题。 - Florian