• bearophile (8/8) Mar 01 2011 Do you know why DMD doesn't give a compilation error here?
• Bekenn (3/11) Mar 01 2011 I'm not sure that's checkable. I think this falls squarely into the
• bearophile (6/8) Mar 02 2011 The signature of sscanf is something like:
• Bekenn (3/4) Mar 02 2011 With an annotation on the function signature, perhaps, and certainly it
• Trass3r (2/8) Mar 02 2011 What's the D signature of sscanf?
• Simon (5/16) Mar 02 2011 void* after the format arg...
• Simon (5/20) Mar 02 2011 Rather it's the ellipses, which is effectively void*

bearophile <bearophileHUGS lycos.com> writes:

Do you know why DMD doesn't give a compilation error here?


import core.stdc.stdio: sscanf;
immutable int value = 5;
void main() {
    sscanf("10".ptr, "%d".ptr, &value);
}

Bye,
bearophile

Bekenn <leaveme alone.com> writes:

On 3/1/2011 2:33 PM, bearophile wrote:
 Do you know why DMD doesn't give a compilation error here?


 import core.stdc.stdio: sscanf;
 immutable int value = 5;
 void main() {
      sscanf("10".ptr, "%d".ptr,&value);
 }

 Bye,
 bearophile

I'm not sure that's checkable.  I think this falls squarely into the 
realm of "undefined behavior".

bearophile <bearophileHUGS lycos.com> writes:

Bekenn:

 I'm not sure that's checkable.  I think this falls squarely into the
 realm of "undefined behavior".

The signature of sscanf is something like:
int sscanf(char* str, char* format, ...);

Can't D/DMD err on the side of safety and consider the C-style variadic
argument as not const, and so produce an error if you give to them something
that's D const/immutable (and require a cast there)? (Especially a function
like sscanf where the third and successive arguments are known to be modified).

Bye,
bearophile

Bekenn <leaveme alone.com> writes:

On 3/2/11 4:06 AM, bearophile wrote:
 Can't D/DMD err on the side of safety and consider the C-style variadic
argument as not const, and so produce an error if you give to them something
that's D const/immutable (and require a cast there)? (Especially a function
like sscanf where the third and successive arguments are known to be modified).

With an annotation on the function signature, perhaps, and certainly it 
should do this at all times in code marked  safe.

Trass3r <un known.com> writes:

Am 01.03.2011, 23:33 Uhr, schrieb bearophile <bearophileHUGS lycos.com>:

 Do you know why DMD doesn't give a compilation error here?


 import core.stdc.stdio: sscanf;
 immutable int value = 5;
 void main() {
     sscanf("10".ptr, "%d".ptr, &value);
 }

What's the D signature of sscanf?

Simon <s.d.hammett gmail.com> writes:

On 02/03/2011 08:56, Trass3r wrote:
 Am 01.03.2011, 23:33 Uhr, schrieb bearophile <bearophileHUGS lycos.com>:

 Do you know why DMD doesn't give a compilation error here?


 import core.stdc.stdio: sscanf;
 immutable int value = 5;
 void main() {
 sscanf("10".ptr, "%d".ptr, &value);
 }

 What's the D signature of sscanf?

void* after the format arg...

-- 
My enormous talent is exceeded only by my outrageous laziness.
http://www.ssTk.co.uk

Simon <s.d.hammett gmail.com> writes:

On 02/03/2011 11:28, Simon wrote:
 On 02/03/2011 08:56, Trass3r wrote:
 Am 01.03.2011, 23:33 Uhr, schrieb bearophile <bearophileHUGS lycos.com>:

 Do you know why DMD doesn't give a compilation error here?


 import core.stdc.stdio: sscanf;
 immutable int value = 5;
 void main() {
 sscanf("10".ptr, "%d".ptr, &value);
 }

 What's the D signature of sscanf?

 void* after the format arg...

Rather it's the ellipses, which is effectively void*

-- 
My enormous talent is exceeded only by my outrageous laziness.
http://www.ssTk.co.uk