Strange compiler errors [solved]

twosixonetwo · Post by **twosixonetwo** » Sat Aug 02, 2014 8:22 am

While changing my code I encountered the following situation:
Let's say I have this code:

void handleJoyEvent(u16 joy, u16 changed, u16 state);

u8 readVDP60hz()
{
	return (*((u16*)(0xC00004)))&0x1;
};

int main()
{
    // [...]

    JOY_setEventHandler(handleJoyEvent);
    // [...]
}
//no declaration of handleJoyEvent follows

Instead of complaining that I don't declare what handleJoyEvent does, I get these Errors:

Code: Select all

C:/sgdk/lib/libmd.a(main.o): In function `readVDP60hz':
main.c:(.text+0x178): multiple definition of `readVDP60hz'
out/src/main.o:main.c:(.text+0xf8): first defined here
C:/sgdk/lib/libmd.a(main.o): In function `main':
main.c:(.text+0x184): multiple definition of `main'
out/src/main.o:main.c:(.text+0x104): first defined here
C:/sgdk/bin/ld: Warning: size of symbol `main' changed from 232 in out/src/main.
o to 330 in C:/sgdk/lib/libmd.a(main.o)
make: *** [out/rom.out] Error 1

I don't have multiple declarations of those functions, neither in main.c nor in multiple files. If I remove the JOY_setEventHandler-call the code compiles fine (without warnings).

Does someone know why that is? Might this be due to my makefile or is this unavoidable?

Stef · Post by **Stef** » Sat Aug 02, 2014 9:25 am

I think there is something really wrong in your makefile, i guess you don't use the one included in SGDK ?

twosixonetwo · Post by **twosixonetwo** » Sat Aug 02, 2014 12:50 pm

Well, the newest makefile doesn't work for me since I've got the sega.s and the rom_head.c in my src folder:

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C:\sgdk\projects\SVPDemo>%GDK_WIN%\bin\make -f makefile.gen
make: *** No rule to make target `C:/sgdk/src/boot/sega.s', needed by `src/boot/sega.s'.  Stop.

If I change

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$(SRC)/boot/sega.s: $(LIBSRC)/boot/sega.s
	$(MKDIR) -p $(SRC)/boot
	$(CP) $< $@

$(SRC)/boot/rom_head.c: $(LIBSRC)/boot/rom_head.c
	$(MKDIR) -p $(SRC)/boot
	$(CP) $< $@

to

Code: Select all

$(SRC)/boot/sega.s: $(SRC)/boot/sega.s
	$(MKDIR) -p $(SRC)/boot
	$(CP) $< $@

$(SRC)/boot/rom_head.c: $(SRC)/boot/rom_head.c
	$(MKDIR) -p $(SRC)/boot
	$(CP) $< $@

the compilation works AND I am getting the compiler error I've described above

Chilly Willy · Post by **Chilly Willy** » Sat Aug 02, 2014 5:50 pm

You have an extra ";" following the close brace for readVDP60hz().

twosixonetwo · Post by **twosixonetwo** » Sat Aug 02, 2014 7:25 pm

Yes, that's unnecessary, doesn't create any problems though. (IIRC) it's merely an empty statement.
I removed it and the strange compiler message remains...

Stef · Post by **Stef** » Sat Aug 02, 2014 10:03 pm

Did you removed the sega.s file from the base SGDK folder ?
If yes you should not do it, the new makefile will just copy the sega.s from the original SGDK folder then you can freely modify it if you want...
From your error it looks like you removed the original sega.s file.

twosixonetwo · Post by **twosixonetwo** » Mon Aug 04, 2014 11:35 am

Ahh... well now I realize what your change meant. I have never written a makefile from scratch and wasn't really aware of how the change was supposed to work.

So, I now use the newest makefile (https://code.google.com/p/sgdk/source/b ... n194&r=194) and the strange compiler errors are still there.

If I have a little more time I might narrow it down to a test case and see if it has to do with the implementation of JOY_setEventHandler, compiler version or mistakes in my code

twosixonetwo · Post by **twosixonetwo** » Wed Aug 06, 2014 10:21 am

Case closed. Updated sgdk from 0.95 to 0.96d and the strange errors went away. Sorry for the confusion caused.

Stef · Post by **Stef** » Wed Aug 06, 2014 12:03 pm

Glad to hear you fixed it