Building a library using autotools from cmake

Question

This is my first try with cmake and I would like to have, if possible, some feedbacks about what I did since some problems remain.

In the CMakeLists.txt of the library folder, I created two makefile targets: configure-antlr3c and antlr3c. The first target runs the autotools configuration shell script, the second one runs the make executable to build the library:

# CMakeLists.txt in libantlr3c-3.1.3 
add_custom_target(
  configure-antlr3c
  ${SHELL_EXECUTABLE} configure
  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
)

add_custom_target(
  antlr3c
   ${MAKE}
   DEPENDS configure-antlr3c
   WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
)

The main problem is thatconfigure-antlr3c target is always "out of date", so it will always be executed even if no changes happened. Moreover, I necessarily need to generate my cmake makefiles in a separate directory (not in the root directory of my project) to avoid overriding the autotools Makefile of the library...

Has anyone had this problem (building autotools projects with cmake) ? And if so, what have been your solutions ?

Thank you.

EDIT : Solution In the root CMakeLists.txt:

include(ExternalProject)
ExternalProject_Add(
  libantlr3c
  SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/lib/libantlr3c-3.1.3
  CONFIGURE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/lib/libantlr3c-3.1.3/configure --prefix=${CMAKE_CURRENT_SOURCE_DIR}/lib/libantlr3c-3.1.3
  PREFIX ${CMAKE_CURRENT_SOURCE_DIR}/lib/libantlr3c-3.1.3
  BUILD_COMMAND make
  BUILD_IN_SOURCE 1
)

Answer 1

I think that you'd be better off using the ExternalProject feature of cmake. I guess you have your project and have libantrl in a sub directory?

project
      +- libantlr
      +- mysrc
  ---- etc ----

If that's the case, you can do something like this in the top level CMakeLists.txt:

cmake_minimum_required(VERSION 2.8)
project(test)
include(ExternalProject)
ExternalProject_Add(libantlr
    SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/libantlr
    CONFIGURE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/libantlr/configure --prefix=<INSTALL_DIR>
    BUILD_COMMAND ${MAKE})

The <INSTALL_DIR> is expanded to something like libantlr-prefix, so things are installed in your build tree rather than in /usr/local, which is what autotools would do without a prefix.