[Bug middle-end/106582] Wrong code generation resulting in HardFault

[jankowski938 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106582

--- Comment #5 from Piotr <jankowski938 at gmail dot com> ---
(In reply to Andrew Pinski from comment #4)
> >
> 080157fe:   movs    r3, #0
> 08015800:   ldr.w   r2, [r9, #20]
> 08015804:   str     r2, [r3, #12]
> 
> This is doing a store at the address 12 which is invalid normally.
> I suspect for your code you need -fno-delete-null-pointer-checks .
> 
> Or you are missing a null pointer check.
> 
> The code does:
>    if (pQueryChunk && ioIsValid(pRawChunk))
>    {
>     pQueryChunk->pSrcDriver = pRawChunk->pSrcDriver;
>    }
>    else
>    {
>     if (pParser)
>     {
>      pQueryChunk->pSrcDriver = pParser->pSourceDriver;
>     }
>    }
> 
> But the store for "pQueryChunk->pSrcDriver" is not checked to see if
> pQueryChunk was a non-null pointer before doing the store after the check
> that pParser was a non-null pointer.
> 
> 
> That is I don't think this is a bug in GCC.

Thank you for debugging our code :) 

1. that chunk was vetted earlier in this function, so there is no need to check
it again here.
2. Offset 12 is not invalid as it is a 32bits (not 64) platform and it is
natively aligned