OCLint.3.OCLintConfig.cmake-file

OCLintConfig.cmake file

 

1. Introduction 

OCLintConfig.cmake is as a CMake Module which is refered by CMakeLists.txt of oclint modules(oclint-core，oclint-driver，

oclint-metrics，oclint-reporters，oclint-rules). The following is an example:

SET(CMAKE_MODULE_PATH
    ${CMAKE_MODULE_PATH}
    "${CMAKE_CURRENT_SOURCE_DIR}/../oclint-core/cmake"
    )

INCLUDE(OCLintConfig)

 

 

 

2. What's CMake Module?

"Code reuse is a valuable technique in software development and CMake has been designed to support it.

Allowing CMakeLists files to make use of reusable modules enables the entire community to share

reusable sections of code. For CMake, these sections are called cmake-modules and can be found

in the Modules subdirectory of your installation." Ref[1]

 

 

3. What does OCLintConfig.cmake do?

3.1 Set values for variables

OCLintConfig.cmake set the value for the following variable: 

CMAKE_DISABLE_SOURCE_CHANGES

CMAKE_DISABLE_IN_SOURCE_BUILD

CMAKE_MACOSX_RPATH

CMAKE_CXX_FLAGS

CMAKE_SHARED_LINKER_FLAGS

EXECUTABLE_OUTPUT_PATH

 

3.2 Find and Include the LLVMConfig module

Set the include directory to ${LLVM_INCLUDE_DIRS}.

Set the link directory to ${LLVM_LIBRARY_DIRS}.

Add -D define flags from ${LLVM_DEFINITIONS} to the compilation of source files.

 

3.3 CLANG_LIBRARIES

 

LLVM_MAP_COMPONENTS_TO_LIBNAMES(REQ_LLVM_LIBRARIES asmparser bitreader instrumentation mcparser option support frontendopenmp)

SET(CLANG_LIBRARIES
    clangToolingCore
    clangTooling
    clangFrontend
    clangDriver
    clangSerialization
    clangParse
    clangSema
    clangAnalysis
    clangEdit
    clangASTMatchers
    clangAST
    clangLex
    clangBasic)

 

 

A. llvm_map_components_to_libnames function

 

# Find the libraries that correspond to the LLVM components
# that we wish to use
llvm_map_components_to_libnames(llvm_libs support core irreader)

This function (llvm_map_components_to_libnames) is defined in LLVM-Config.cmake. It will map the components to libraries list which is saved

in the first parameter (llvm_libs, in the above code snippet). 

 

llvm-config

"The list of libraries is determined by using the llvm_map_components_to_libnames() CMake function.

For a list of available components look at the output of running llvm-config --components."  Ref[3]

 

The install path of llvm by 'brew install llvm' is /usr/local/opt/llvm/bin/llvm-config.

The output of './llvm-config --components' as the following: 

$ ./llvm-config --components
aggressiveinstcombine all all-targets analysis asmparser asmprinter 
binaryformat bitreader bitstreamreader bitwriter cfguard codegen 
core coroutines coverage debuginfocodeview debuginfodwarf 
debuginfogsym debuginfomsf debuginfopdb demangle 
dlltooldriver dwarflinker dwp engine executionengine 
extensions filecheck frontendopenacc frontendopenmp 
fuzzmutate globalisel instcombine instrumentation 
interfacestub interpreter ipo irreader jitlink libdriver 
lineeditor linker lto mc mca mcdisassembler mcjit mcparser 
mirparser native nativecodegen objcarcopts object objectyaml 
option orcjit orcshared orctargetprocess passes profiledata 
remarks runtimedyld scalaropts selectiondag support symbolize 
tablegen target textapi transformutils vectorize windowsmanifest 
x86 x86asmparser x86codegen x86desc x86disassembler x86info xray

 

B. CLANG_LIBRARIES

Set the CLANG_LIBRARIES variable to the libraries list: clangToolingCore, clangTooling, clangFrontend,

clangDriver, clangSerialization, clangParse, clangSema, clangAnalysis, clangEdit, clangASTMatchers, 

clangAST, clangLex, clangBasic. 

The header files for these libraries are at the ${LLVM_ROOT_PATH}/clang/include/clang. The source file for 

these libraries are ${LLVM_ROOT_PATH}/clang/lib .

 

 

---

Reference

1. Using Modules

https://cmake.org/cmake/help/book/mastering-cmake/chapter/Modules.html

 

2. add_definitions

Add -D define flags to the compilation of source files.

https://cmake.org/cmake/help/v3.23/command/add_definitions.html

 

3. Building LLVM with CMake

https://llvm.org/docs/CMake.html