Issue
I have a C++ CMake project that is compiled both on Linux and Windows. On Windows, this is done via Visual Studio/MSVCC.
In CMAKE and in VS, the build is set up as Debug, but it seems that no debug symbols are ever being made in the VS build - so debugging is impossible.
When looking over the Detailed output for VS, I saw this:
cl : command line warning D9002: ignoring unknown option '-g'
That suggests to me that it doesn't recognize the -g flag like GCC/Clang do.
Here is the CMake arguments:
SET(CMAKE_CXX_STANDARD 17)
SET(CMAKE_CXX_STANDARD_REQUIRED ON)
SET(BUILD_MODE Debug)
SET(CMAKE_CXX_FLAGS "-Wall")
SET(CMAKE_CXX_FLAGS_DEBUG "-g")
SET(CMAKE_CXX_FLAGS_RELEASE "-O3")
How do I make this compatible with Visual Studio? I've tried looking all over, but most related posts seem to be about C#/.net, or much older versions of VS.
The project does use the QT library if that matters.
UPDATE:
It turns out BUILD_MODE was something added by someone else so that each sub-project would not individually need to be set to release or debug, we could just set it once in the root level Cmakelists. They did all actually use CMAKE_BUILD_TYPE as intended.
Also, the answers here were correct. Setting the CMAKE_CXX_FLAGS directly was wiping away the defaults, causing the Debug build to not have options like /Zi in MSVCC, preventing debug symbols and all debugging. It also introduced an unrecognized flag "-g" which MSVCC couldn't understand.
I completely remove the SET_CXX_FLAGS from every Cmakelists.txt in the project, and everything is working perfectly.
Should I need to add to them, I will use the _INIT option as suggested.
Solution
You have to compile with a different mode set with CMAKE_BUILD_TYPE as in
cmake -DCMAKE_BUILD_TYPE=DEBUG <sourcedir>
You never set those flags directly. If you want to add a new flag to a debug mode like for example a stack protector, you should use the *_INIT variables.
You can further distinguish which OS you are running with the UNIX, WIN32 and MSVC cmake boolean predefined constants:
if ( UNIX )
set( CMAKE_CXX_FLAGS_DEBUG_INIT "-fstack-protector" )
elseif( WIN32 )
set( CMAKE_CXX_FLAGS_DEBUG_INIT "/GS" )
endif()
Answered By - Henrique Bucher Answer Checked By - Dawn Plyler (WPSolving Volunteer)