undefined reference to `WinMain' in eclipse IDE with cygwin (setup-x86_64) - c++

Question

I am currently doing unit testing for a project of c/c++ in eclipse IDE (Version: Luna Service Release 2 (4.4.2)) and I have recently upgraded my cygwin to cygwin64 to make it compatible with c++17 standard and my g++ version is g++ (GCC) 10.2.0, But I am not able to build my testsuites in eclipse, I have set the environment path to "C:\cygwin64\bin", But still I am getting the below error. Could you please help me with the below error:
Console output after building my project :
make all
Building file:
C:/Accurev/AngioJet_Development_ver1/CS/AngioJet/Firmware/src/ClinicalFeatures/door.cpp
Invoking: Cygwin C++ Compiler
g++ -DUNIT_TESTING - "C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../../AngioJet/Firmware/build/PicoZed_FSBL_bsp/ps7_cortexa9_0/include" -I"C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../testsupport/" -I"C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../testsupport/Source" -I"C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../../AngioJet/Firmware/src/Platform/Zynq7000" - I"C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../../AngioJet/Firmware/src/HostInterface" -I"C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../../AngioJet/Firmware/soup/treck/6_0_1_56/include" -I"C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../../Einstein/src/Platform/Zynq7000" -I"C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../../Einstein/src/Common" -I"C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../../AngioJet/Firmware/src/Common" -I"C:/Accurev/AngioJet_Development_ver1/CS/ut/testsuites/Firmware/hell/../../../../AngioJet/Firmware/src/ClinicalFeatures" -O0 -g -fprofile-arcs -ftest-coverage -Wall -c -fmessage-length=0 -MMD -MP -MF"src/door.d" -MT"src/door.d" -o "src/door.o" "C:/Accurev/AngioJet_Development_ver1/CS/AngioJet/Firmware/src/ClinicalFeatures/door.cpp"
Finished building: C:/Accurev/AngioJet_Development_ver1/CS/AngioJet/Firmware/src/ClinicalFeatures/door.cpp
Building target: helll.exe
Invoking: Cygwin C++ Linker
g++ -fprofile-arcs -o "helll.exe" ./src/door.o -lgcov -lbfd
/usr/lib/gcc/x86_64-pc-cygwin/10/../../../../x86_64-pc-cygwin/bin/ld: /usr/lib/gcc/x86_64-pc-cygwin/10/../../../../lib/libcygwin.a(libcmain.o): in function `main':
/usr/src/debug/cygwin-3.3.6-1/winsup/cygwin/lib/libcmain.c:37: undefined reference to `WinMain'
collect2: error: ld returned 1 exit status
make: *** [makefile:47: helll.exe] Error 1
07:05:17 Build Finished (took 4s.531ms)
`*
I have uninstalled and reinstalled the softwares. Also I have built a new project from scratch which is building fine but whenever i try to build my project it is not building.
While doing unit testing in eclipse we create the project as c++ project and import the source files mentioned below and the structure is as follow:
Source file - door.cpp, door.h
door.h:
#include "global.h"
namespace lDOOR { void close( BasicTypes::UInt8 mode ); }
door.cpp:
#include "door.h"
void lDOOR::close(void)
{
//Normal Mode
close(BscMsg::NORMAL);
}
and we do the unit testing for the above functions present in .cpp file in the file created by us door_testsuite.h which is as follows:
#include <cxxtest/TestSuite.h>
class door_TestSuite: public CxxTest::TestSuite {
public:
void setUp(){}
void teardown(){}
void testDoorLDoorClose()
{
BscMsg::UInt8 mode = 2;
lDOOR::close(mode);
TS_ASSERT_EQUALS();
}};
And when I test the above code in cygwin terminal it executes completely fine.

Answer 1

This means there is no WinMain function, which is the entry point to Windows windows programs. Yes, confusing. You can choose to either build a program as a console program or windows program. (There are a few other types that are irrelevant) In a console program, the entry point is main (As with the entire world of computing), but in a windows program, it is WinMain. This question has a good answer that goes into depth about it, but you either need to switch the type of program to console, or (If your program is creating and using windows) add a WinMain function.
Sorry if this is confusing, it is difficult to differentiate between Windows, the OS, and windows, the type of program. Also, my knowledge on this subject is all from VSCode, so may be completely or partially incorrect.
TLDR: Either add a WinMain function, or switch to building your program as a windows program.