[cfe-dev] GNU extensions - different behaviour of g++ and clang for taking address of temporary array

[Aleksei Sidorin via cfe-dev]

Thank you for explanation Richard!
As I see, turning 'c' into 'const int *' doesn't suppress GCC 
diagnostic. However, this is all information I need.

19.02.2018 21:44, Richard Smith пишет:
> On 19 Feb 2018 10:31, "Aleksei Sidorin via cfe-dev" 
> <cfe-dev at lists.llvm.org <mailto:cfe-dev at lists.llvm.org>> wrote:
>
>     Hi all,
>
>     Consider a test case:
>
>     #include<stdio.h>
>
>     typedefinta[];
>
>     voidprint(int*c) {
>        printf("%d\n", c[0]);
>     }
>
>     intmain() {
>        print(a{2});
>     return0;
>     }
>
>     `g++ -std=gnu++11 -fsyntax-only` fails to compile this code:
>     "error: taking address of temporary array". However, clang accepts
>     it without any warnings and there is no any ASan output for it.
>     Could someone explain me if it a GCC or Clang issue?
>
>
> It's a GCC bug -- this code is valid. The array to pointer conversion 
> is used to convert the int[1] temporary to a pointer; a reference is 
> not bound to it.
>
> (GCC's behaviour is not unreasonable, though, and perhaps we should 
> warn on such constructs. I would imagine the GCC diagnostic would be 
> suppressed by making c a pointer to const int?)
>
>     -- 
>     Best regards,
>     Aleksei Sidorin,
>     SRR, Samsung Electronics
>
>
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>
>

-- 
Best regards,
Aleksei Sidorin,
SRR, Samsung Electronics

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