undefined reference to `WinMain' with cygwin and cmake - c++

Question

I am trying to build a executable with cygwin in windows 7 and I get the following error in the linking stage.
/usr/lib/gcc/x86_64-pc-cygwin/4.9.3/../../../../lib/libcygwin.a(libcmain.o): In function `main':
/usr/src/debug/cygwin-2.3.0-1/winsup/cygwin/lib/libcmain.c:39: undefined reference to `WinMain'
/usr/src/debug/cygwin-2.3.0-1/winsup/cygwin/lib/libcmain.c:39:(.text.startup+0x7f): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `WinMain'
collect2: error: ld returned 1 exit status
I dont understand why it tries to find WinMain. I have a cpp file with int main(int, char**) function defined which is part of the build. I do not understand why it is trying to use libcmain.c, which is part of cygwin during executable creation. I am using cmake and it has following:
add_executable(binary_name ${SOURCE_FILES})
This application need to be a console type application and does not have a GUI.
EDIT:
My main function is as follows.
#include "gtest/gtest.h"
int main(int argc, char **argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}

Answer 1

Three points I would recommend to check:
Check the command line(s) that are called by activating verbose output. See Using CMake with GNU Make: How can I see the exact commands?
Are you sure that you really have only one main() function in your code?
Is the source file containing main() function directly added to the add_executable() call?
Because I just have given your code a try with the latest CMake package available in Cygwin and it seems to work just fine (with and without #include <windows.h> in main.cpp).
In the hope that it might help finding your problem, here is what I've done:
$ export PATH=/usr/local/bin:/usr/bin:/bin:/usr/bin
$ cmake --version
cmake version 3.3.2
CMake suite maintained and supported by Kitware (kitware.com/cmake).
$ c++ -v --version
c++ (GCC) 4.9.3
gcc-Version 4.9.3 (GCC)
GNU C (GCC) Version 4.9.3 (x86_64-pc-cygwin)
GNU assembler version 2.25 (x86_64-pc-cygwin) using BFD version (GNU Binutils) 2.25
GNU assembler (GNU Binutils) 2.25
GNU ld (GNU Binutils) 2.25
$ cmake ..
-- The CXX compiler identification is GNU 4.9.3
-- Check for working CXX compiler: /usr/bin/c++.exe
-- Check for working CXX compiler: /usr/bin/c++.exe -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found GTest: /cygdrive/c/gtest-1.7.0/lib/.libs/libgtest.a
-- Configuring done
-- Generating done
-- Build files have been written to: ...
Scanning dependencies of target binary_name
[ 50%] Building CXX object CMakeFiles/binary_name.dir/main.cpp.o
[100%] Linking CXX executable binary_name.exe
[100%] Built target binary_name
$ ./binary_name.exe
[==========] Running 0 tests from 0 test cases.
[==========] 0 tests from 0 test cases ran. (3 ms total)
[ PASSED ] 0 tests.
I've used the following CMakeLists.txt:
cmake_minimum_required(VERSION 3.0)
project(binary_name CXX)
enable_testing()
set(GTEST_ROOT /cygdrive/c/gtest-1.7.0)
set(CMAKE_LIBRARY_PATH ${CMAKE_LIBRARY_PATH} "${GTEST_ROOT}/lib/.libs")
find_package(GTest REQUIRED)
add_executable(binary_name main.cpp)
target_include_directories(binary_name PRIVATE ${GTEST_INCLUDE_DIRS})
target_link_libraries(binary_name PRIVATE ${GTEST_LIBRARIES})
Resulting in the following link line CMakeFiles/binary_name.dir/link.txt:
/usr/bin/c++.exe
-Wl,--enable-auto-import CMakeFiles/binary_name.dir/main.cpp.o
-o binary_name.exe
-Wl,--out-implib,libbinary_name.dll.a
-Wl,--major-image-version,0,--minor-image-version,0
/cygdrive/c/gtest-1.7.0/lib/.libs/libgtest.a
More References
Most references to similar problems where in combination with SDL or far more general:
undefined reference to 'WinMain' with SDL compiling in a native enviroment
Undefined reference to WinMain in Cygwin
g++ linker problem with libcygwin.a -> linker error libcygwin
WINMAIN and main() in C++ (Extended)