Re: [ghogenso@u.washington.edu: Problems with .cpp extension]

[Gordon Hogenson <ghogenso@u.washington.edu>]

Under DJGPP 1.12 with G++ 2.6.0, I experience the following problem
when using filename extension .cpp instead of .cc.  The assembler
output contains the incorrect ".file" heading.  Included here is an
intentional link-time error to illustrate that ld then
reports the wrong filename.

--------------------- main.cpp ------------------------------

int main()
{

  int i;
  for (i = 0; i < 55; i++)
    my_function(i); 

}

------------------- output of 'gcc main.cpp -o main -g -v' --------

Reading specs from d:/gcc/lib/specs
gcc version 2.6.0
 d:/gcc/bin/cpp.exe -lang-c++ -v -undef -D__GNUC__=2 -D__GNUG__=2 
-D__cplusplus -D__GNUC_MINOR__=6 -Dunix -Di386 -DGO32 -DMSDOS -D__unix__ 
-D__i386__ -D__GO32__ -D__MSDOS__ -D__unix -D__i386 -D__GO32 -D__MSDOS -g 
main.cpp f:/cc000073
GNU CPP version 2.6.0 (80386, BSD syntax)
#include "..." search starts here:
#include <...> search starts here:
 d:/gcc/cplusinc
 d:/gcc/include
 /usr/local/lib/g++-include
 /usr/local/include
 /usr/local/go32/include
 /usr/local/lib/gcc-lib/go32/2.6.0/include
 /usr/include
End of search list.
 d:/gcc/bin/cc1plus.exe f:/cc000073 -quiet -dumpbase main.cc -g -version 
-o f:/cca00073
GNU C++ version 2.6.0 (80386, BSD syntax) compiled by GNU C version 2.6.0.
main.cpp: In function `int main()':
main.cpp:7: warning: implicit declaration of function `int my_function(...)'
 d:/gcc/bin/as.exe -o f:/ccb00073 f:/cca00073
 d:/gcc/bin/ld.exe -o main d:/gcc/lib/crt0.o -Ld:/gcc/lib f:/ccb00073 
-lgcc -lg -lc -lgcc
main.cc:7: main: undefined reference to `my_function'
     ^^^^^
     This is incorrect!

--------------------------------------------------------------------------

Running 'gcc main.cpp -g -v -S -o main.s', we get the file main.s:

-------------------------------------------------------------------------

	.file	"main.cc"
gcc2_compiled.:
___gnu_compiled_cplusplus:
.text
	.align 2
	.def	_main;	.val	_main;	.scl	2;	.type	044;	.endef
.globl _main
_main:
	pushl %ebp
	movl %esp,%ebp
	subl $4,%esp
	.def	.bf;	.val	.;	.scl	101;	.line	3;	.endef
	call ___main
	.def	_i;	.val	-4;	.scl	1;	.type	04;	.endef
	.ln	4
	movl $0,-4(%ebp)
L2:
	.def	.bb;	.val	.;	.scl	100;	.line	4;	.endef
	cmpl $54,-4(%ebp)
	jle L5
	jmp L3
	.align 2,0x90
L5:
	.ln	5
	pushl -4(%ebp)
	call _my_function
	addl $4,%esp
	.def	.eb;	.val	.;	.scl	100;	.line	5;	.endef
L4:
	incl -4(%ebp)
	jmp L2
	.align 2,0x90
L3:
	xorl %eax,%eax
	jmp L1
	.align 2,0x90
	jmp L1
	.align 2,0x90
	.ln	7
L1:
	.def	.ef;	.val	.;	.scl	101;	.line	7;	.endef
	leave
	ret
	.def	_main;	.val	.;	.scl	-1;	.endef
----------------------------------------------------------------------------
Thus the '.file' is incorrect in the assembler output.
----------------------------------------------------------------------------

Thanks,
Gordon Hogenson