gcc invoked from make on cygwin strips symbols from object file

gcc invoked from make on cygwin strips symbols from object file

[André Kwakernaak]

cccHi all,

I'm porting an application from a Linux environment to Cygwin. During this process I encountered the following: it seems that invoking gcc from a Makefile behaves differently over gcc being invoked directly from the command line. When ggc is invoked from within a Makefile, symbols are stripped from the object file. When gcc is invoked with exactly the same arguments, the symbols remain in the object file.

I've made a small test case, narrowing the problem down.

Consider a C file containing the following:
cyg
#include <stdio.h>

void hello()

{

	printf("Hello world\n");

}

and a Makefile:
hello.o:	
	gcc -c hello.c

clean:
	rm -f *.o *.d *.exe

When I run make an object file is build. The output of "nm hello.o" displays:
00000000 b .bss
00000000 d .data
00000000 t .text

If I run "gcc -c hello.c" directly from the command line I get object file for which nm displays:
00000000 b .bss
00000000 d .data
00000000 r .rdata
00000000 t .text
00000000 T _hello
         U _printf

As you can see in the latter case the expected symbols are in the object file. Why are they missing when using the Makefile? I can't get my head around it.

I'm on Cygin 1.7.9, gcc 3.4.4, make 3.81

Any help is greatly appreciated.

André Kwakernaak

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Re: gcc invoked from make on cygwin strips symbols from object file

[Marco atzeri]

On 9/19/2011 2:01 PM, André Kwakernaak wrote:
> cccHi all,
>
> I'm porting an application from a Linux environment to Cygwin. During this process I encountered the following: it seems that invoking gcc from a Makefile behaves differently over gcc being invoked directly from the command line. When ggc is invoked from within a Makefile, symbols are stripped from the object file. When gcc is invoked with exactly the same arguments, the symbols remain in the object file.
>
> I've made a small test case, narrowing the problem down.
>
> Consider a C file containing the following:
> cyg
> #include<stdio.h>
>
> void hello()
>
> {
>
> 	printf("Hello world\n");
>
> }
>
> and a Makefile:
> hello.o:	
> 	gcc -c hello.c
>
> clean:
> 	rm -f *.o *.d *.exe
>
> When I run make an object file is build. The output of "nm hello.o" displays:
> 00000000 b .bss
> 00000000 d .data
> 00000000 t .text

this looks unlikely as hello.c miss the definition of printf

>
> If I run "gcc -c hello.c" directly from the command line I get object file for which nm displays:
> 00000000 b .bss
> 00000000 d .data
> 00000000 r .rdata
> 00000000 t .text
> 00000000 T _hello
>           U _printf
>
> As you can see in the latter case the expected symbols are in the object file.
 > Why are they missing when using the Makefile? I can't get my head 
around it.
>
> I'm on Cygin 1.7.9, gcc 3.4.4, make 3.81
>
> Any help is greatly appreciated.
>
> André Kwakernaak

is make the cygwin one ?

$ make --version
GNU Make 3.81
Copyright (C) 2006  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.

This program built for i686-pc-cygwin

$ which make
/usr/bin/make


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Re: gcc invoked from make on cygwin strips symbols from object file

[André Kwakernaak]

Marco,

Thank you very much. You pointed me in the one direction I did not yet investigate. I'm really embarrassed by what I just found out.

Here's what happened. There was a second installation of Cygwin on this development machine... I did not know about this installation. The installation I used did not have make installed at at all.. The PATH variable included the bin directory of the second Cygwin installation. So I was using make of another cygwin installation. Removing the second installation and installing make solved the problem.

This took me 2 days...

Regards, 


André Kwakernaak

> 
> this looks unlikely as hello.c miss the definition of printf
> 
> 
> is make the cygwin one ?
> 
> $ make --version
> GNU Make 3.81
> Copyright (C) 2006  Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.
> There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
> PARTICULAR PURPOSE.
> 
> This program built for i686-pc-cygwin
> 
> $ which make
> /usr/bin/make

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