On Tue, 17 Jul 2012 12:43:46 +0100, Jacob Carlborg <d...@me.com> wrote:
On 2012-07-17 09:06, Mehrdad wrote:
My eyes!! They're bleeding!!
First I wanted to know if my interpretation is correct and then I was
trying to figure out how my tool should behave if it encounters a
function like this.
After a bit of googling and a test with my local MSVC9 I think old-style
variadics look like this:
#include <varargs.h>
#include <stdio.h>
void foo(va_alist)
va_dcl
{
va_list p;
va_start(p);
vprintf("%d %d %d\n", p);
}
void main()
{
foo(1, 2, 3);
}
(the above runs and outputs "1 2 3" on the console)
The same syntax is/was supported by GNU C, see:
http://ftp.gnu.org/old-gnu/Manuals/glibc-2.2.3/html_chapter/libc_34.html#SEC676
I believe, if you see an "old-style" function declaration in a header file
like:
int foo ();
that you can't actually assume anything about it's parameters, it may have
/any/ number of parameters, and may or may not be variadic.
e.g. see: http://msdn.microsoft.com/en-us/library/efx873ys.aspx
The "declaration" syntax shown there for a function with 2 arguments is
simply:
double old_style();
In short, I don't think you can produce a valid .di/d file for old-style
declarations automatically, it will require a manual step where the user
enters the function type-arguments.
However, if you see an old-style:
int foo(void);
you can be sure it has 0 parameters and can happily produce:
extern (C) int foo();
So, I think you should assume no old-style function declarations but have
a command line option/mode which assumes all functions declarations are
old-style. In this mode you would output something like..
extern (C) <return-type> <function-name>(/*TODO: add args here*/);
and require the user manually find and define these.
I can't think of any other way you could do it.
R
p.s. I found this copy of the C spec online:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf
section 6.7.5.3 appears to deal with function declarations.
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