GDAL Not Linking - c++

Question

I'm trying to get my program running on Windows. It depends on GDAL, a library for loading GIS data. It compiles and links fine on both Linux and macOS. I'm using CMake with MinGW and I'm running into linking errors like this:
undefined reference to `GDALRasterBand::RasterIO(GDALRWFlag, int, int, int, int, void*, int, int, GDALDataType, long, long, GDALRasterIOExtraArg*)'
CMakeFiles\Routes.dir/objects.a(elevation.cpp.obj): In function `ZN13ElevationData9calcStatsEv':
C:/Users/Logan/Documents/Routes/src/elevation/elevation.cpp:138: undefined reference to `GDALDataset::GetRasterXSize()'
C:/Users/Logan/Documents/Routes/src/elevation/elevation.cpp:139: undefined reference to `GDALDataset::GetRasterYSize()'
CMakeFiles\Routes.dir/objects.a(elevation.cpp.obj): In function `ZN13ElevationData17createOpenCLImageEv':
C:/Users/Logan/Documents/Routes/src/elevation/elevation.cpp:206: undefined reference to `GDALRasterBand::RasterIO(GDALRWFlag, int, int, int, int, void*, int, int, GDALDataType, long, long, GDALRasterIOExtraArg*)'
I compiled GDAL with VS2017 and I've verified that it is installed where I am specifying in my CMake File. Here is the relevant portions of the CMakeLists.txt:
IF (WIN32)
message(STATUS "Compiling for Windows")
set(GDAL_LIBRARY "C:/warmerda/bld/lib/gdal_i.lib")
set(GDAL_INCLUDE_DIR "C:/warmerda/bld/include/")
find_package(OpenCL REQUIRED)
include_directories(${OpenCL_INCLUDE_DIRS})
ELSE()
...
message(STATUS ${GDAL_LIBRARY})
target_link_libraries(Routes ${GDAL_LIBRARY} ${OpenCL_LIBRARIES})
I almost never do development on Windows so I'm kind of stuck. I've tried linking against the dll as well with no avail. Any ideas?

Answer 1

Apparently you're attempting to link a library you compiled with VC++ with object
files that you're compiling with GCC (MinGW). That doesn't work.
GCC and VC++ have different and incompatible ABIs,
and in particular different name mangling protocols.
Hence the mangled function names emitted by MinGW in your object code will
not match any exported by your VC++ compiled library. You will need to
build the GDAL library with MinGW.

Answer 2

Thanks #MikeKinghan! I had been pulling my hair out for couple of days! Your answer clicked right away. For those who want to have no headache with the libraries, just use MSYS2 (msys2.org). Then using pacman in the msys2 command prompt, get the MingW (pacman -S mingw-w64-x86_64-gcc) and GDAL (pacman -S mingw-w64-x86_64-gdal).