Date: Wed, 09 Oct 1996 17:43:50 +0000
From: Bill Currie <billc AT blackmagic DOT tait DOT co DOT nz>
Subject: Re: Possible GAS bug
To: Francisco Gochez <arcanix AT erols DOT com>
Cc: djgpp AT delorie DOT com
Message-id: <325BE456.67A8@blackmagic.tait.co.nz>
Organization: Tait Electronics NZ
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References: <53egsu$1f8 AT boursy DOT news DOT erols DOT com>

Francisco Gochez wrote:
> 
> It took me an hour to find a syntax error in an assembly language module
> I had written, because the error was being caused by whitespace in the
> code.  It occured after placing spaces (not on purpose) after backslashes
> at the end of lines of macros.
> Here is an example:
> 
> #define mymacro() \
> movl %eax, %ebx   ; \_SPACES_PLACED_HERE_
> movl %ecx, %edx   ; \
> movl %edx, %eax
> 
> When GAS encounters these spaces, it appears to choke on pieces of the
> code, warning the programmer that parts of certain lines have been
> ignored, and failing to compile in the process.

Actually, the problem is in cpp (rather than gas, which knows nothing about #defines) and it's 
not really a bug.  The '\' must ALWAYS be at the END of the line. ie no trailing white space etc.

Bill