Re: [Tinycc-devel] global variables in tcc

[Daniel Glöckner]

Hi,

On Mon, Apr 01, 2013 at 04:55:18PM +0200, Lluís Batlle i Rossell wrote:
> > GCC and Clang allow these to be merged together at link-time, which
> > means users who make mistakes such as missing `extern' in header files
> > still get the multiple definitions merged.
> > 
> > tcc is stricter and perhaps more conformant in disallowing this.
> 
> I think that the C standard requires the gcc and clang behaviour, 'extern'
> never being a required word.
> 
> No?

I just took a look inside the N1570 C11 draft.
Chapter 6.9 paragraph 5 says:

"If an identifier declared with external linkage is used in an expression
([...]), somewhere in the entire program there shall be exactly one external
definition for the identifier; otherwise, there shall be no more than one."

  Daniel