www.digitalmars.com         C & C++   DMDScript  

digitalmars.D - Bug or what?

reply "Phil Lavoie" <maidenphil hotmail.com> writes:
Ok so me and one of my colleagues have been working on some code 
at a distance. We both use dmd as the compiler. I am under 
Windows, she OSX.

It is not uncommon that she experiences more strictness in the 
type system than I do. For example, something like this does 
compile for me, but not for her:

int func(size_t i)
{
   return i;
}

It passes my compilation. She gets an error msg about implicit 
casting of uint to int. I'm just wondering... has anybody else 
experienced that and what is the expected behavior?

Thanks,
Phil
Aug 27 2014
next sibling parent reply "Brian Schott" <briancschott gmail.com> writes:
On Wednesday, 27 August 2014 at 19:51:48 UTC, Phil Lavoie wrote:

 Ok so me and one of my colleagues have been working on some 
 code at a distance. We both use dmd as the compiler. I am under 
 Windows, she OSX.

 It is not uncommon that she experiences more strictness in the 
 type system than I do. For example, something like this does 
 compile for me, but not for her:

 int func(size_t i)
 {
   return i;
 }

 It passes my compilation. She gets an error msg about implicit 
 casting of uint to int. I'm just wondering... has anybody else 
 experienced that and what is the expected behavior?

 Thanks,
 Phil


size_t is different on 32-bit and 64-bit systems. If she's 
building 64-bit binaries on OS-X and you're building 32-bit 
binaries on Windows you could see different messages.

Either way, size_t is unsigned, int is signed, and you should 
probably be getting the warning as well.
Aug 27 2014
parent "Phil Lavoie" <maidenphil hotmail.com> writes:
On Wednesday, 27 August 2014 at 19:56:29 UTC, Brian Schott wrote:

 On Wednesday, 27 August 2014 at 19:51:48 UTC, Phil Lavoie wrote:

 Ok so me and one of my colleagues have been working on some 
 code at a distance. We both use dmd as the compiler. I am 
 under Windows, she OSX.

 It is not uncommon that she experiences more strictness in the 
 type system than I do. For example, something like this does 
 compile for me, but not for her:

 int func(size_t i)
 {
  return i;
 }

 It passes my compilation. She gets an error msg about implicit 
 casting of uint to int. I'm just wondering... has anybody else 
 experienced that and what is the expected behavior?

 Thanks,
 Phil


 size_t is different on 32-bit and 64-bit systems. If she's 
 building 64-bit binaries on OS-X and you're building 32-bit 
 binaries on Windows you could see different messages.

 Either way, size_t is unsigned, int is signed, and you should 
 probably be getting the warning as well.


All right thanks Brian you were right on point.
I 32 she 64.

Indeed, I should have gotten a a warning because it is unsafe. 
When I emit code for 64 bit machine I get the error messages she 
does, which at least allows me to avoid making her compilation 
fail.

Thanks again Brian!
Phil
Aug 27 2014
prev sibling parent reply "MacAsm" <jckj33 gmail.com> writes:
On Wednesday, 27 August 2014 at 19:51:48 UTC, Phil Lavoie wrote:

 Ok so me and one of my colleagues have been working on some 
 code at a distance. We both use dmd as the compiler. I am under 
 Windows, she OSX.

 It is not uncommon that she experiences more strictness in the 
 type system than I do. For example, something like this does 
 compile for me, but not for her:

 int func(size_t i)
 {
   return i;
 }

 It passes my compilation. She gets an error msg about implicit 
 casting of uint to int. I'm just wondering... has anybody else 
 experienced that and what is the expected behavior?

 Thanks,
 Phil


size_t is a typedef to unsigned (check out 
http://dlang.org/type.html). So this warning is correct. I don't 
get this warning too. Maybe it's the type-checking that does 
differ on OSX. Are you using same compiler version and flags?
Aug 27 2014
parent reply "Phil Lavoie" <maidenphil hotmail.com> writes:
On Wednesday, 27 August 2014 at 20:05:27 UTC, MacAsm wrote:

 On Wednesday, 27 August 2014 at 19:51:48 UTC, Phil Lavoie wrote:

 Ok so me and one of my colleagues have been working on some 
 code at a distance. We both use dmd as the compiler. I am 
 under Windows, she OSX.

 It is not uncommon that she experiences more strictness in the 
 type system than I do. For example, something like this does 
 compile for me, but not for her:

 int func(size_t i)
 {
  return i;
 }

 It passes my compilation. She gets an error msg about implicit 
 casting of uint to int. I'm just wondering... has anybody else 
 experienced that and what is the expected behavior?

 Thanks,
 Phil


 size_t is a typedef to unsigned (check out 
 http://dlang.org/type.html). So this warning is correct. I 
 don't get this warning too. Maybe it's the type-checking that 
 does differ on OSX. Are you using same compiler version and 
 flags?


Yeah yeah I checked it out and we both use same versions and 
everything. Basically, to bit word size coherent I should just 
have writtent this instead:

ptrdiff_t func(size_t i) {return i;}

Though it is still somewhat unsafe, at least it behaves the same 
on both our machines.

Phil
Aug 27 2014
parent reply "Phil Lavoie" <maidenphil hotmail.com> writes:
On Wednesday, 27 August 2014 at 20:28:11 UTC, Phil Lavoie wrote:

 On Wednesday, 27 August 2014 at 20:05:27 UTC, MacAsm wrote:

 On Wednesday, 27 August 2014 at 19:51:48 UTC, Phil Lavoie 
 wrote:

 Ok so me and one of my colleagues have been working on some 
 code at a distance. We both use dmd as the compiler. I am 
 under Windows, she OSX.

 It is not uncommon that she experiences more strictness in 
 the type system than I do. For example, something like this 
 does compile for me, but not for her:

 int func(size_t i)
 {
 return i;
 }

 It passes my compilation. She gets an error msg about 
 implicit casting of uint to int. I'm just wondering... has 
 anybody else experienced that and what is the expected 
 behavior?

 Thanks,
 Phil


 size_t is a typedef to unsigned (check out 
 http://dlang.org/type.html). So this warning is correct. I 
 don't get this warning too. Maybe it's the type-checking that 
 does differ on OSX. Are you using same compiler version and 
 flags?


 Yeah yeah I checked it out and we both use same versions and 
 everything. Basically, to bit word size coherent I should just 
 have writtent this instead:

 ptrdiff_t func(size_t i) {return i;}

 Though it is still somewhat unsafe, at least it behaves the 
 same on both our machines.

 Phil


Note that the compiler behaves the same, the code, not 
necessarily.
Aug 27 2014
parent Marco Leise <Marco.Leise gmx.de> writes:
Am Wed, 27 Aug 2014 20:30:08 +0000
schrieb "Phil Lavoie" <maidenphil hotmail.com>:


 On Wednesday, 27 August 2014 at 20:28:11 UTC, Phil Lavoie wrote:

 On Wednesday, 27 August 2014 at 20:05:27 UTC, MacAsm wrote:

 On Wednesday, 27 August 2014 at 19:51:48 UTC, Phil Lavoie 
 wrote:

 Ok so me and one of my colleagues have been working on some 
 code at a distance. We both use dmd as the compiler. I am 
 under Windows, she OSX.

 It is not uncommon that she experiences more strictness in 
 the type system than I do. For example, something like this 
 does compile for me, but not for her:

 int func(size_t i)
 {
 return i;
 }

 It passes my compilation. She gets an error msg about 
 implicit casting of uint to int. I'm just wondering... has 
 anybody else experienced that and what is the expected 
 behavior?

 Thanks,
 Phil


 size_t is a typedef to unsigned (check out 
 http://dlang.org/type.html). So this warning is correct. I 
 don't get this warning too. Maybe it's the type-checking that 
 does differ on OSX. Are you using same compiler version and 
 flags?


 Yeah yeah I checked it out and we both use same versions and 
 everything. Basically, to bit word size coherent I should just 
 have writtent this instead:

 ptrdiff_t func(size_t i) {return i;}

 Though it is still somewhat unsafe, at least it behaves the 
 same on both our machines.

 Phil


 
 Note that the compiler behaves the same, the code, not 
 necessarily.


In my opinion this should always give you a compiler warning,
as it is not portable to 64-bit:

uint func(size_t i) {return i;}

But that has been discussed and reported to death already :D

I'm also somewhat pedantic about assigning unsigned to signed
types and vice versa. Most of the times I'd rather change the
code so that I can keep using e.g. unsigned absolute values
instead of differences.

-- 
Marco
Aug 27 2014