Bug #332: Alias analyzer doesn't alias int with volatile int! - BLAST - Open-Source Projects

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Bug #332

open

Alias analyzer doesn't alias int with volatile int!

Added by Pavel Shved over 14 years ago. Updated about 13 years ago.

Status:

Open

Priority:

Normal

Assignee:

Pavel Shved

Category:

Target version:

Start date:

08/03/2010

Due date:

% Done:

Estimated time:

Detected in build:

pre-ldv

Platform:

Published in build:

Description

For this program *p is not aliased with a, and BLAST reports an unsafe.

int main()
{
        int volatile a = 4;
        int * const p = &a;
        p = &a;
        a = a - 4;
        if (*p != 0){
                ERROR: goto ERROR;
        }
        return 0;
}

If we remove volatile qualifier, the types--as BLAST understands them--start to match, and the program passes.

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Updated by Alexey Khoroshilov almost 14 years ago

Priority changed from Low to Normal

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Updated by Evgeny Novikov about 13 years ago

Is this the case for the new implementation of aliases?

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Updated by Pavel Shved about 13 years ago

Yes, it still is the case. There is a test for this case, and it's still not passed. I did not address this problem at all, since what I fixed were only queries to the alias analysis mechanism, not the code that gets the full-program flow-insensitive may-alias information.

Since we now (most likely) have the fast iterations, this problem could be addressed sooner.

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