Re: malloc: bison-2.1+, prototype mismatch vs. stdlib.h (C++ mode)

[Hans Aberg]

On 20 Oct 2007, at 02:40, David Fang wrote:

> > > 	I've just encountered a problem where the compiler rejects  
> > > bison's prototype for "void* malloc(YYSIZE_T);" because it  
> > > doesn't match with <stdlib.h>, which looks like "void* malloc 
> > > (size_t) __THROW ... ;" (ubuntu7).  The problem only manifests  
> > > when compiling the resulting source file as in C++ (otherwise,  
> > > the __THROW macro is empty).  It looks like the bison skeleton is  
> > > using "defined __cplusplus" to conditionally insert this  
> > > prototype, rather than including <cstdlib>, a standard C++  
> > > wrapper header, which should resolve the inconsistency, and be  
> > > safely portable.
> > > 	This issue is the same on at least 2.1 and 2.3.  Does anyone  
> > > else see this issue on ubuntu7 or other UNIX system?  (Another  
> > > ubuntu7 distro didn't have this issue, so I need to get more  
> > > feedback from my bug reporter.)
> >
> > Well, is it the C or C++ header? In C++, standard names start with  
> > "std::".

> The error message was pointing to "the original declaration" in / 
> usr/include/stdlib.h, which already contained provisions for C++  
> (namespace, no-throw specification) without going through  
> <cstdlib>.  In any case, the prototype mismatch is attributed to  
> the difference in the throw specification, which is missing from  
> the bison skeleton's version (not any other issue).  The quick fix  
> I see is to just include <stdlib.h> or if __cplusplus, <cstdlib>.   
> If this results in std::malloc, then a conditional definition of a  
> "std::" namespace prefix should take care of calls to malloc in C++  
> mode.  Thoughts?
>
> Actually, I misspoke about the platform: it was occuring on ubuntu6  
> not 7.

I meant: do you Bison-compile to generate C or C++ output.

Once upon the time, the C output had informal support for C++, but  
that was dropped, I think. The "if __cplusplus" suggests you have  
some compile for C that does not work with C++.

  Hans Aberg