<div class="gmail_quote"><font color="#222222" face="arial, sans-serif">I've run into a problem where a CMake script that worked with make, xcode, and ninja generators no longer works for XCode after adding ExternalProject_Add to build libpng using their provided CMakeLists.txt as an external. It does not appear to build the correct library files, and I believe this is an issue more closely related to cmake than the fault of libpng's script. </font><span style="color:rgb(34,34,34);font-family:arial,sans-serif"> </span><span style="color:rgb(34,34,34);font-family:arial,sans-serif">I believe the problem is that libs are not created in the originally expected directories, so instead of lib/libpng.a, xcode creates lib/Debug/libpng.a, and then the main Xcode project wrapped around the libpng Xcode project is unable to find the lib file. I know I could manually write a workaround but I believe this is an issue that can occur in many places and is the typical sort of thing that could or should be handled by the cmake generator.</span><span style="color:rgb(34,34,34);font-family:arial,sans-serif"> Any help would be greatly appreciated. I've included additional information below.</span><br>
<div><span style="color:rgb(34,34,34);font-family:arial,sans-serif"><br></span></div><div><span style="color:rgb(34,34,34);font-family:arial,sans-serif">Cheers!</span></div>
<div><span style="color:rgb(34,34,34);font-family:arial,sans-serif">Andrew Hundt</span></div><div><br></div><div>
Here is the relevant script, External_PNG.cmake with the problem:</div><div><font color="#222222" face="arial, sans-serif"><div>-------------------------------</div><div>set(USE_PROJECT_CMAKE_MODULE_PATH "-DCMAKE_MODULE_PATH=${MAKE_MODULE_PATH}")</div>
<div><br></div><div>if(NOT PNG_ROOT)</div><div> set(PNG_ROOT ${CMAKE_SOURCE_DIR}/external/libpng)</div><div>endif()</div><div><br></div><div>ExternalProject_Add(PNG</div><div> DEPENDS ZLIB</div><div> SOURCE_DIR ${PNG_ROOT}</div>
<div> CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR> -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS} -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS} -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} ${USE_PROJECT_CMAKE_MODULE_PATH}</div>
<div> )</div><div>ExternalProject_Get_Property(PNG install_dir)</div><div><br></div><div><br></div><div>add_library(png STATIC IMPORTED )</div><div>set_target_properties(png PROPERTIES IMPORTED_LOCATION ${install_dir}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}png16${CMAKE_STATIC_LIBRARY_SUFFIX} )</div>
<div>add_dependencies(png PNG)</div><div>set(PNG_LIBRARIES png ${ZLIB_LIBRARIES}) #png always requires zlib, so just keep them together</div><div>set(PNG_DIR ${install_dir})</div><div>set(PNG_INCLUDE_DIRS ${install_dir}/include)</div>
<div><br></div><div><br></div><div>find_package_handle_standard_args(PNG DEFAULT_MSG PNG_LIBRARIES PNG_INCLUDE_DIRS)</div><div><br></div><div>if(PNG_FOUND)</div><div> set(PNG_LIBRARIES_OPTIONAL ${PNG_LIBRARIES})</div><div>
endif()</div><div><br></div></font></div><div><br><span style="color:rgb(34,34,34);font-family:arial,sans-serif">-------------------------------</span></div>
<div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">Here is an email I sent to the libpng list:</div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">Please pardon me if this is not the right list or way to post this information, but I wanted to provide feedback on an issue I was able to find. I believe I have found a problem with the libpng16 cmakelists.txt file when using the Xcode generator.</div>
<div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
I take the following steps in an OS X terminal:</div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">cd libpng </div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
mkdir build</div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">cd build</div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
cmake .. -G Xcode</div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">open libpng.xcodeproj</div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">I then hit run in the Xcode window</div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">The output does not seem to account for the Debug path in Xcode, and it does not seem to build in Release mode by default. I've included the terminal session as well below, so the binaries do not appear in the correct location. I can also supply more information if it would be helpful.<br clear="all">
<div><div><br></div>Cheers!<div>Andrew Hundt</div></div><div><br></div><div><br></div><div><br></div><div><div>Andrew-Hundts-MacBook-Pro-15-2011:external ahundt$ cd external/libpng</div><div>Andrew-Hundts-MacBook-Pro-15-2011:libpng ahundt$ ls</div>
<div>ANNOUNCE<span style="white-space:pre-wrap"> </span>autogen.sh<span style="white-space:pre-wrap"> </span>example.c<span style="white-space:pre-wrap"> </span>libpngpf.3<span style="white-space:pre-wrap"> </span>pngdebug.h<span style="white-space:pre-wrap"> </span>pngmem.lo<span style="white-space:pre-wrap"> </span>pngrio.lo<span style="white-space:pre-wrap"> </span>pngtest.c<span style="white-space:pre-wrap"> </span>pngwtran.c</div>
<div>CHANGES<span style="white-space:pre-wrap"> </span>build<span style="white-space:pre-wrap"> </span>install-sh<span style="white-space:pre-wrap"> </span>libtool<span style="white-space:pre-wrap"> </span>pngerror.c<span style="white-space:pre-wrap"> </span>pngmem.o<span style="white-space:pre-wrap"> </span>pngrio.o<span style="white-space:pre-wrap"> </span>pngtest.<span style="background-color:rgb(255,255,204)">png</span><span style="white-space:pre-wrap"> </span>pngwtran.lo</div>
<div>CMakeLists.txt<span style="white-space:pre-wrap"> </span>config.guess<span style="white-space:pre-wrap"> </span>libpng-config<span style="white-space:pre-wrap"> </span>ltmain.sh<span style="white-space:pre-wrap"> </span>pngerror.lo<span style="white-space:pre-wrap"> </span>pngnow.<span style="background-color:rgb(255,255,204)">png</span><span style="white-space:pre-wrap"> </span>pngrtran.c<span style="white-space:pre-wrap"> </span>pngtrans.c<span style="white-space:pre-wrap"> </span>pngwtran.o</div>
<div>INSTALL<span style="white-space:pre-wrap"> </span>config.h<span style="white-space:pre-wrap"> </span><a href="http://libpng-config.in/" style="color:rgb(17,85,204)" target="_blank">libpng-config.in</a><span style="white-space:pre-wrap"> </span>missing<span style="white-space:pre-wrap"> </span>pngerror.o<span style="white-space:pre-wrap"> </span>pngpread.c<span style="white-space:pre-wrap"> </span>pngrtran.lo<span style="white-space:pre-wrap"> </span>pngtrans.lo<span style="white-space:pre-wrap"> </span>pngwutil.c</div>
<div>LICENSE<span style="white-space:pre-wrap"> </span><a href="http://config.h.in/" style="color:rgb(17,85,204)" target="_blank">config.h.in</a><span style="white-space:pre-wrap"> </span>libpng-manual.txt<span style="white-space:pre-wrap"> </span><span style="background-color:rgb(255,255,204)">png</span>.5<span style="white-space:pre-wrap"> </span>pngget.c<span style="white-space:pre-wrap"> </span>pngpread.lo<span style="white-space:pre-wrap"> </span>pngrtran.o<span style="white-space:pre-wrap"> </span>pngtrans.o<span style="white-space:pre-wrap"> </span>pngwutil.lo</div>
<div>Makefile<span style="white-space:pre-wrap"> </span>config.log<span style="white-space:pre-wrap"> </span>libpng.3<span style="white-space:pre-wrap"> </span><span style="background-color:rgb(255,255,204)">png</span>.c<span style="white-space:pre-wrap"> </span>pngget.lo<span style="white-space:pre-wrap"> </span>pngpread.o<span style="white-space:pre-wrap"> </span>pngrutil.c<span style="white-space:pre-wrap"> </span>pngusr.dfa<span style="white-space:pre-wrap"> </span>pngwutil.o</div>
<div>Makefile.am<span style="white-space:pre-wrap"> </span>config.status<span style="white-space:pre-wrap"> </span>libpng.pc<span style="white-space:pre-wrap"> </span><span style="background-color:rgb(255,255,204)">png</span>.h<span style="white-space:pre-wrap"> </span>pngget.o<span style="white-space:pre-wrap"> </span>pngprefix.h<span style="white-space:pre-wrap"> </span>pngrutil.lo<span style="white-space:pre-wrap"> </span>pngwio.c<span style="white-space:pre-wrap"> </span>projects</div>
<div>Makefile.in<span style="white-space:pre-wrap"> </span>config.sub<span style="white-space:pre-wrap"> </span><a href="http://libpng.pc.in/" style="color:rgb(17,85,204)" target="_blank">libpng.pc.in</a><span style="white-space:pre-wrap"> </span><span style="background-color:rgb(255,255,204)">png</span>.lo<span style="white-space:pre-wrap"> </span>pnginfo.h<span style="white-space:pre-wrap"> </span>pngpriv.h<span style="white-space:pre-wrap"> </span>pngrutil.o<span style="white-space:pre-wrap"> </span>pngwio.lo<span style="white-space:pre-wrap"> </span>scripts</div>
<div>README<span style="white-space:pre-wrap"> </span>configure<span style="white-space:pre-wrap"> </span>libpng.sym<span style="white-space:pre-wrap"> </span><span style="background-color:rgb(255,255,204)">png</span>.o<span style="white-space:pre-wrap"> </span>pnglibconf.dfn<span style="white-space:pre-wrap"> </span>pngread.c<span style="white-space:pre-wrap"> </span>pngset.c<span style="white-space:pre-wrap"> </span>pngwio.o<span style="white-space:pre-wrap"> </span>stamp-h1</div>
<div>TODO<span style="white-space:pre-wrap"> </span><a href="http://configure.ac/" style="color:rgb(17,85,204)" target="_blank">configure.ac</a><span style="white-space:pre-wrap"> </span>libpng16-config<span style="white-space:pre-wrap"> </span>pngbar.jpg<span style="white-space:pre-wrap"> </span>pnglibconf.h<span style="white-space:pre-wrap"> </span>pngread.lo<span style="white-space:pre-wrap"> </span>pngset.lo<span style="white-space:pre-wrap"> </span>pngwrite.c<span style="white-space:pre-wrap"> </span>test-driver</div>
<div>aclocal.m4<span style="white-space:pre-wrap"> </span>contrib<span style="white-space:pre-wrap"> </span><a href="http://libpng16.la/" style="color:rgb(17,85,204)" target="_blank">libpng16.la</a><span style="white-space:pre-wrap"> </span>pngbar.<span style="background-color:rgb(255,255,204)">png</span><span style="white-space:pre-wrap"> </span>pnglibconf.out<span style="white-space:pre-wrap"> </span>pngread.o<span style="white-space:pre-wrap"> </span>pngset.o<span style="white-space:pre-wrap"> </span>pngwrite.lo<span style="white-space:pre-wrap"> </span>tests</div>
<div>arm<span style="white-space:pre-wrap"> </span>depcomp<span style="white-space:pre-wrap"> </span>libpng16.pc<span style="white-space:pre-wrap"> </span>pngconf.h<span style="white-space:pre-wrap"> </span>pngmem.c<span style="white-space:pre-wrap"> </span>pngrio.c<span style="white-space:pre-wrap"> </span>pngstruct.h<span style="white-space:pre-wrap"> </span>pngwrite.o</div>
<div>Andrew-Hundts-MacBook-Pro-15-2011:libpng ahundt$ mkdir xcodebuild</div><div>Andrew-Hundts-MacBook-Pro-15-2011:libpng ahundt$ cd xcodebuild/</div><div>Andrew-Hundts-MacBook-Pro-15-2011:xcodebuild ahundt$ cmake .. -G Xcode</div>
<div>-- The C compiler identification is Clang 4.2.0</div><div>-- Check for working C compiler using: Xcode</div><div>-- Check for working C compiler using: Xcode -- works</div><div>-- Detecting C compiler ABI info</div>
<div>
-- Detecting C compiler ABI info - done</div><div>-- Found ZLIB: /usr/lib/libz.dylib (found version "1.2.5") </div><div>-- Configuring done</div><div>-- Generating done</div><div>-- Build files have been written to: /Users/ahundt/Source_Code/external/libpng/xcodebuild</div>
<div>Andrew-Hundts-MacBook-Pro-15-2011:xcodebuild ahundt$ ls</div><div>CMakeCache.txt<span style="white-space:pre-wrap"> </span>CMakeScripts<span style="white-space:pre-wrap"> </span>cmake_install.cmake<span style="white-space:pre-wrap"> </span>libpng.a<span style="white-space:pre-wrap"> </span>libpng.pc<span style="white-space:pre-wrap"> </span>libpng16-config<span style="white-space:pre-wrap"> </span>pnglibconf.h</div>
<div>CMakeFiles<span style="white-space:pre-wrap"> </span>CTestTestfile.cmake<span style="white-space:pre-wrap"> </span>libpng-config<span style="white-space:pre-wrap"> </span>libpng.dylib<span style="white-space:pre-wrap"> </span>libpng.xcodeproj<span style="white-space:pre-wrap"> </span>libpng16.pc</div>
<div>Andrew-Hundts-MacBook-Pro-15-2011:xcodebuild ahundt$ open libpng.xcodeproj/</div><div>Andrew-Hundts-MacBook-Pro-15-2011:xcodebuild ahundt$ ls -alh</div><div>total 136</div><div>drwxr-xr-x@ 17 ahundt staff 578B May 30 17:54 .</div>
<div>drwxr-xr-x@ 114 ahundt staff 3.8K May 30 17:53 ..</div><div>-rw-r--r-- 1 ahundt staff 13K May 30 17:53 CMakeCache.txt</div><div>drwxr-xr-x 8 ahundt staff 272B May 30 17:53 CMakeFiles</div><div>drwxr-xr-x 40 ahundt staff 1.3K May 30 17:53 CMakeScripts</div>
<div>-rw-r--r-- 1 ahundt staff 3.2K May 30 17:53 CTestTestfile.cmake</div><div>drwxr-xr-x 7 ahundt staff 238B May 30 17:54 Debug</div><div>-rw-r--r-- 1 ahundt staff 15K May 30 17:53 cmake_install.cmake</div>
<div>lrwxr-xr-x 1 ahundt staff 15B May 30 17:53 libpng-config -> libpng16-config</div><div>lrwxr-xr-x 1 ahundt staff 10B May 30 17:53 libpng.a -> libpng16.a</div><div>drwxr-xr-x@ 3 ahundt staff 102B May 30 17:54 libpng.build</div>
<div>lrwxr-xr-x 1 ahundt staff 14B May 30 17:53 libpng.dylib -> libpng16.dylib</div><div>lrwxr-xr-x 1 ahundt staff 11B May 30 17:53 libpng.pc -> libpng16.pc</div><div>drwxr-xr-x 5 ahundt staff 170B May 30 17:54 libpng.xcodeproj</div>
<div>-rw-r--r-- 1 ahundt staff 2.3K May 30 17:53 libpng16-config</div><div>-rw-r--r-- 1 ahundt staff 242B May 30 17:53 libpng16.pc</div><div>-rw-r--r-- 1 ahundt staff 7.1K May 30 17:53 pnglibconf.h</div>
<div>Andrew-Hundts-MacBook-Pro-15-2011:xcodebuild ahundt$ ls -alh Debug/</div><div>total 2976</div><div>drwxr-xr-x 7 ahundt staff 238B May 30 17:54 .</div><div>drwxr-xr-x@ 17 ahundt staff 578B May 30 17:54 ..</div>
<div>-rw-r--r-- 1 ahundt staff 845K May 30 17:54 libpng16d.a</div><div>-rwxr-xr-x 1 ahundt staff 368K May 30 17:54 libpng16d.dylib</div><div>-rwxr-xr-x 1 ahundt staff 65K May 30 17:54 pngstest</div><div>-rwxr-xr-x 1 ahundt staff 33K May 30 17:54 pngtest</div>
<div>-rwxr-xr-x 1 ahundt staff 165K May 30 17:54 pngvalid</div></div></div>
</div><br>