How to add_subdirectory after a externalproject_add()? - cmake

Question

I have to download zlib to use in my project.
I use externlproject_add() to downaload all zlib repository, build and install it.
After it, I want do install a lib that is part of zlib repository: minizip.
How to set this dependency on cmake?
zlib module:
cmake_minimum_required ( VERSION 2.8.7 )
include (ExternalProject)
if(UNIX)
# An external project for zlib
SET (GIT_URL https://github.com/madler/zlib.git)
SET (ZLIB_INSTALL ${CMAKE_CURRENT_BINARY_DIR})
SET (ZLIB_INCLUDE ${CMAKE_BINARY_DIR}/include/zlib)
SET (ZLIB_STATIC ${CMAKE_BINARY_DIR}/lib/libz.a )
SET (MINIZIP_DIR ${CMAKE_CURRENT_BINARY_DIR}/ZLIB/src/ZLIB/contrib/minizip)
ExternalProject_Add(zlib
PREFIX zlib
GIT_REPOSITORY ${GIT_URL}
INSTALL_DIR ${ZLIB_INSTALL}
PATCH_COMMAND ${CMAKE_COMMAND} -E remove <SOURCE_DIR>/zconf.h
BUILD_IN_SOURCE 1
PATCH_COMMAND ""
CONFIGURE_COMMAND <SOURCE_DIR>/configure --prefix=<INSTALL_DIR> --includedir=${ZLIB_INCLUDE}
)
find_package(ZLIB REQUIRED)
if(ZLIB_FOUND)
add_subdirectory (${MINIZIP_DIR})
endif(ZLIB_FOUND)
SET (ZLIB_INCLUDE_DIR ${ZLIB_INSTALL}/include/zlib)
SET (ZLIB_LIBRARY "${ZLIB_INSTALL}")
ADD_LIBRARY (ZLIB_LIB STATIC IMPORTED DEPENDS zlib)
SET_TARGET_PROPERTIES (ZLIB_LIB PROPERTIES IMPORTED_LOCATION "${ZLIB_STATIC}")
endif(UNIX)
With this zlib module I have an error that following directory
/home/lais/Imagens/agent/build/ZLIB/src/ZLIB/contrib/minizip
doesn't exist yet when I run
cmake ..
And it's true. Doesn't exist yet. I should tell cmake it. But I don't know how to do it.

Answer 1

I solved it download a zip file that have minizip.
cmake_minimum_required ( VERSION 2.8.7 )
include (ExternalProject)
project (zlib)
if(UNIX)
# An external project for zlib
SET (URL http://www.winimage.com/zLibDll/unzip101e.zip)
SET (MINIZIP_INSTALL ${CMAKE_CURRENT_BINARY_DIR})
SET (MINIZIP_STATIC ${CMAKE_BINARY_DIR}/lib/minizip.a )
message ("zlib = ${zlib}")
ExternalProject_Add(minizip
DEPENDS zlib
PREFIX minizip
URL ${URL}
INSTALL_DIR ${MINIZIP_INSTALL}
BUILD_IN_SOURCE make
CONFIGURE_COMMAND ""
)
SET (MINIZIP_LIBRARY "${MINIZIP_INSTALL}")
ADD_LIBRARY (MINIZIP_LIB STATIC IMPORTED DEPENDS minizip, zlib)
SET_TARGET_PROPERTIES (MINIZIP_LIB PROPERTIES IMPORTED_LOCATION "${MINIZIP_STATIC}")
endif(UNIX)