CMake activate external program

Question

I want to run the following command

win_bison.exe --output="calc.tab.cpp" --defines="calc.tab.h"  "calc.y"

and then create an executable from the products of this command with CMake

add_executable(Calc calc.tab.cpp calc.tab.h)

All the files (win_bison.exe, calc.y) are found in the CMakeLists.txt folder.

What is the correct way to do so? Please give the commands explanations.

Answer 1

If your project is indeed structured like that, then you can use the FindBison CMake module

find_package(BISON)

BISON_TARGET(MyCalcParser calc.y 
  ${CMAKE_CURRENT_BINARY_DIR}/calc.tab.cpp
  DEFINES_FILE ${CMAKE_CURRENT_BINARY_DIR}/calc.tab.h)

add_executable(Calc ${BISON_MyCalcParser_OUTPUTS})

Notes

• You might have to influence the places the find_package searches by setting the BISON_DIR variable in the command line invocation of CMake, i.e. -DBISON_DIR=[source dir], or you can place the Bison executable somwhere that is system-wide accessible/invocable.