CMAKE conditionally run cppcheck

Question

I have a CMakefile that defines cppcheck as described in Cppcheck support in CMake works great, but I want to be able to compile my code over and over again and not run cppcheck until I think I am close to done, and then run cppcheck prior to commit.

cppcheck is too slow to have as part of my edit/compile/test/debug cycle.

What is the best practice for this? I am thinking something like define a variable and generate files, and build and build and build. e.g.

In CMakeLists.txt

if(CPPCHECK STREQUAL "yes")
  set(CMAKE_CXX_CPPCHECK "cppcheck")
endif()

While writing code

cmake3 -G "Unix Makefiles" ..
cmake3  --build . 
cmake3  --build .

Then before committing code

cmake3 -G "Unix Makefiles" -DCPPCHECK=yes ..
cmake3  --build . 

Is there a better way?

Answer 1

I do it mostly like the question described - only run code analysis if a particular variable is set. I typically follow a pattern like this in my top-level CMakeLists.txt:

option(ENABLE_CODE_ANALYSIS "Run code analysis" OFF)
message(STATUS "ENABLE_CODE_ANALYSIS       ${ENABLE_CODE_ANALYSIS}")

if(ENABLE_CODE_ANALYSIS)
    find_program(cppcheck cppcheck)
    message(STATUS "cppcheck                   ${cppcheck}")
    if(NOT (cppcheck MATCHES "NOTFOUND"))
        # Notes:
        # - unmatchedSuppression needed since not all source files are
        #   analyzed simultaneously
        # - unusedFunction needed since not all source files are
        #   analyzed simultaneously
        # - template needed to force "warning" into output string, and
        #   to make the 'id' available for suppression
        set(CMAKE_CXX_CPPCHECK "${cppcheck}"
            "--enable=all"
            "--inconclusive"
            "--inline-suppr"
            "--quiet"
            "--suppress=unmatchedSuppression"
            "--suppress=unusedFunction"
            "--template='{file}:{line}: warning: {id} ({severity}): {message}'")
    endif()
endif(ENABLE_CODE_ANALYSIS)

Typically I will do the same for clang-tidy, and have ENABLE_CODE_ANALYSIS enable both cppcheck and clang-tidy.

I default to no code analysis, because code analysis tends to be slow. But it can be enabled by doing cmake -G "my generator" -DENABLE_CODE_ANALYSIS=ON .. when generating the build system.