如何省略单个源文件的调试信息？

Question

我正在为解析调试信息的工具编写测试，我想在我的调试目标中省略单个编译单元（源文件）的调试信息。有没有办法用cmake来完成这个？

显然，我可以对编译器标志进行硬编码，但我想让我的构建在不同的操作系统和工具链（比如 gnu 和 msvc）之间保持可移植性。

即时更改CMAKE_BUILD_TYPE 似乎不起作用。

Answer 1

为此，您必须修改默认标志，因为使用多配置生成器您无法强制使用特定的构建类型。这只是一个简单的示例，展示了如何从默认值中删除调试标志，然后将其重新添加。然后您可以更新此示例以使用变量来收集所有源文件和一些 if 语句来检查哪个编译器是用于测试-g 或/Zi。

cmake_minimum_required(VERSION 3.12)

project(sample)

message( "\${CMAKE_CXX_FLAGS_RELEASE} = ${CMAKE_CXX_FLAGS_RELEASE}")
message( "\${CMAKE_CXX_FLAGS_DEBUG} = ${CMAKE_CXX_FLAGS_DEBUG}")
string(REPLACE "-g" "" CMAKE_CXX_FLAGS_DEBUG ${CMAKE_CXX_FLAGS_DEBUG})
string(REPLACE "/Zi" "" CMAKE_CXX_FLAGS_DEBUG ${CMAKE_CXX_FLAGS_DEBUG})
string(REPLACE "-g" "" CMAKE_CXX_FLAGS_RELWITHDEBINFO ${CMAKE_CXX_FLAGS_RELWITHDEBINFO})
string(REPLACE "/Zi" "" CMAKE_CXX_FLAGS_RELWITHDEBINFO ${CMAKE_CXX_FLAGS_RELWITHDEBINFO})
message( "\${CMAKE_CXX_FLAGS_DEBUG} = ${CMAKE_CXX_FLAGS_DEBUG}")
message( "\${CMAKE_CXX_FLAGS_RELWITHDEBINFO} = ${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
set_source_files_properties(file1.cpp PROPERTIES COMPILE_FLAGS "/Zi")

add_executable( sample file1.cpp file2.cpp )

Answer 2

您可以访问 cmake 每个配置使用的默认编译标志（请参阅this 答案）。您还可以在任何源文件上设置COMPILE_FLAGS 属性。因此，在创建目标后，它应该像查询您的语言的默认编译选项一样简单，并使用 set_source_files_properties 应用适当的默认值。

例如，这是一个非常简单的项目的 CMakeLists.txt：

cmake_minimum_required(VERSION 3.6.1)

project(MyProj)

set_source_files_properties(file1.cpp PROPERTIES COMPILE_FLAGS ${CMAKE_CXX_FLAGS_RELEASE})

get_source_file_property(FILE1_FLAGS file1.cpp COMPILE_FLAGS)
get_source_file_property(FILE2_FLAGS file2.cpp COMPILE_FLAGS)

message( "\${FILE1_FLAGS} = ${FILE1_FLAGS}")
message( "\${FILE2_FLAGS} = ${FILE2_FLAGS}")

add_executable( MyExe file1.cpp file2.cpp )

哪些输出（对于 MSVC）：

${FILE1_FLAGS} = /MD /O2 /Ob2 /DNDEBUG
${FILE2_FLAGS} = NOTFOUND

如果您检查生成的 MyExe.vcxproj，您会看到默认值用于编译 file2.cpp，而对于 file1.cpp，所有配置都使用发布设置：

<ClCompile Include="C:\temp\cmake\file1.cpp">
  <InlineFunctionExpansion Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">AnySuitable</InlineFunctionExpansion>
  <Optimization Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">MaxSpeed</Optimization>
  <RuntimeLibrary Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">MultiThreadedDLL</RuntimeLibrary>
  <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">NDEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
  <InlineFunctionExpansion Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">AnySuitable</InlineFunctionExpansion>
  <Optimization Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">MaxSpeed</Optimization>
  <RuntimeLibrary Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">MultiThreadedDLL</RuntimeLibrary>
  <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">NDEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
  <InlineFunctionExpansion Condition="'$(Configuration)|$(Platform)'=='MinSizeRel|Win32'">AnySuitable</InlineFunctionExpansion>
  <Optimization Condition="'$(Configuration)|$(Platform)'=='MinSizeRel|Win32'">MaxSpeed</Optimization>
  <RuntimeLibrary Condition="'$(Configuration)|$(Platform)'=='MinSizeRel|Win32'">MultiThreadedDLL</RuntimeLibrary>
  <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='MinSizeRel|Win32'">NDEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
  <InlineFunctionExpansion Condition="'$(Configuration)|$(Platform)'=='RelWithDebInfo|Win32'">AnySuitable</InlineFunctionExpansion>
  <Optimization Condition="'$(Configuration)|$(Platform)'=='RelWithDebInfo|Win32'">MaxSpeed</Optimization>
  <RuntimeLibrary Condition="'$(Configuration)|$(Platform)'=='RelWithDebInfo|Win32'">MultiThreadedDLL</RuntimeLibrary>
  <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='RelWithDebInfo|Win32'">NDEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
</ClCompile>
<ClCompile Include="C:\temp\cmake\file2.cpp" />

我没有在其他生成器上尝试过这个，但它应该可以工作。