Launch CMake launched an executable file before building another one?

Question

How can I say that CMake creates and runs an executable file before creating another? So, I have 2 executables "a" and "b", where "a" needs to be executed to create header files for "b". Therefore, "a" takes 2 folders as a parameter, in which it generates header files from xml files from the input directory to the output directory.

Is there a way to tell CMake about this, and also to know when the xml files are changing or when the project "a" is changed to regenerate the files?

Answer 1

If test1 built from test1.c requires the preliminary execution of test2 built from test2.c , then the solution should look like this:

- test1.c -

 #include <stdio.h> int main(void) { printf("Hello world from test1\n"); return 0; } 

- test2.c -

 #include <stdio.h> int main(void) { printf("Hello world from test2\n"); return 0; } 

- CMakeLists.txt -

 cmake_minimum_required(VERSION 2.8.11) project(Test) set(test1_SOURCES test1.c) set(test2_SOURCES test2.c) add_executable(test1 ${test1_SOURCES}) add_executable(test2 ${test2_SOURCES}) add_custom_target(test2_run COMMAND test2 WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} COMMENT "run generated test2 in ${CMAKE_CURRENT_SOURCE_DIR}" SOURCES ${test2_SOURCES} ) add_dependencies(test1 test2_run) 

It generates the following output:

 alex@rhyme cmake/TestDep/build $ cmake .. -- The C compiler identification is GNU 4.8.2 -- The CXX compiler identification is GNU 4.8.2 -- Check for working C compiler: /usr/bin/cc -- Check for working C compiler: /usr/bin/cc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Check for working CXX compiler: /usr/bin/c++ -- Check for working CXX compiler: /usr/bin/c++ -- works -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Configuring done -- Generating done -- Build files have been written to: /home/alex/tmp/cmake/TestDep/build alex@rhyme cmake/TestDep/build $ make test1 Scanning dependencies of target test2 [ 25%] Building C object CMakeFiles/test2.dir/test2.co Linking C executable test2 [ 25%] Built target test2 Scanning dependencies of target test2_run [ 50%] run generated test2 in /home/alex/tmp/cmake/TestDep Hello world from test2 [ 75%] Built target test2_run Scanning dependencies of target test1 [100%] Building C object CMakeFiles/test1.dir/test1.co Linking C executable test1 [100%] Built target test1 

You may also need to use add_custom_command and other related CMake directives if your task requires it.