MinGW/CMake Undefined Reference to ZLib - c++

Question

I have a project I want to build with CMake and compile with MinGW. The project uses Zlib. When I build with CMake I get no errors but then when I run MinGW Make it gives the following output:
C:\Projects\MultiMCBuild>C:\Qt\Tools\mingw492_32\bin\mingw32-make.exe
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[ 50%] Linking CXX shared library ..\libMultiMC_logic.dll
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x1f6c): undefined reference to 'z_inflateEnd'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x29e2): undefined reference to 'z_inflateInit2_'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x2a6d): undefined reference to 'z_get_crc_table'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x2ca7): undefined reference to 'z_inflateEnd'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x2f52): undefined reference to 'z_inflateInit2_'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x2f77): undefined reference to 'z_inflateEnd'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x3239): undefined reference to 'z_inflateInit2_'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x3317): undefined reference to 'z_inflateEnd'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x3626): undefined reference to 'z_crc32'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x371f): undefined reference to 'z_inflate'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x376a): undefined reference to 'z_crc32'
C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj):unzip.c:(.text+0x3a57): undefined reference to 'z_inflateEnd'
C:/Qt/Tools/mingw492_32/bin/../lib/gcc/i686-w64- mingw32/4.9.2/../../../../i686-w64-mingw32/bin/ld.exe: C:/Projects/MultiMCBuild/External/Install/QuaZIP/lib/libquazip.a(unzip.c.obj): bad reloc address 0x20 in section `.eh_frame'
collect2.exe: error: ld returned 1 exit status
logic\CMakeFiles\MultiMC_logic.dir\build.make:3186: recipe for target 'libMultiMC_logic.dll' failed
mingw32-make[2]: * * * [libMultiMC_logic.dll] Error 1
CMakeFiles\Makefile2:1806: recipe for target 'logic/CMakeFiles/MultiMC_logic.dir/all' failed
mingw32-make[1]: * * * [logic/CMakeFiles/MultiMC_logic.dir/all] Error 2
makefile:159: recipe for target 'all' failed
mingw32-make: * * * [all] Error 2
Anyone have a clue what I can do to fix this? I read that the code can't find the ZLib library, how do I link it?
EDIT here is my CMakeLists.txt. I got this from the Git project.

Answer 1

I just tried to generate a small example to reproduce your errors. I took my test file from the home page of zlib http://zlib.net/zpipe.c
My initial CMakeLists.txt was
cmake_minimum_required(VERSION 3.4)
project(zlib_test)
set(ZLIB_TEST_SOURCES zpipe.c)
add_executable(${PROJECT_NAME} ${ZLIB_TEST_SOURCES})
And I got the same errors
[ 50%] Building C object CMakeFiles/zlib_test.dir/zpipe.c.o
[100%] Linking C executable zlib_test
CMakeFiles/zlib_test.dir/zpipe.c.o: In function `def':
zpipe.c:(.text+0x65): undefined reference to `deflateInit_'
zpipe.c:(.text+0xcd): undefined reference to `deflateEnd'
zpipe.c:(.text+0x135): undefined reference to `deflate'
zpipe.c:(.text+0x1cf): undefined reference to `deflateEnd'
zpipe.c:(.text+0x25d): undefined reference to `deflateEnd'
CMakeFiles/zlib_test.dir/zpipe.c.o: In function `inf':
zpipe.c:(.text+0x2eb): undefined reference to `inflateInit_'
zpipe.c:(.text+0x353): undefined reference to `inflateEnd'
zpipe.c:(.text+0x3a4): undefined reference to `inflate'
zpipe.c:(.text+0x404): undefined reference to `inflateEnd'
zpipe.c:(.text+0x476): undefined reference to `inflateEnd'
zpipe.c:(.text+0x4a6): undefined reference to `inflateEnd'
collect2: error: ld returned 1 exit status
make[2]: *** [zlib_test] Error 1
make[1]: *** [CMakeFiles/zlib_test.dir/all] Error 2
make: *** [all] Error 2
After changing CMakeLists.txt to this form
cmake_minimum_required(VERSION 3.4)
project(zlib_test)
find_package(ZLIB REQUIRED)
if (ZLIB_FOUND)
include_directories(${ZLIB_INCLUDE_DIRS})
endif()
set(ZLIB_TEST_SOURCES zpipe.c)
add_executable(${PROJECT_NAME} ${ZLIB_TEST_SOURCES})
target_link_libraries(${PROJECT_NAME} ${ZLIB_LIBRARIES})
I could compile the program.
So your problem is: Where is ZLIB added in your CMakeLists.txt? At least, you need the line find_package(ZLIB REQUIRED).