[PATCH] Bury leaked pointers in a global array to silence a leak detector in --disable-free mode

[Chandler Carruth]

On Fri, Dec 27, 2013 at 2:10 AM, Kostya Serebryany <kcc at google.com> wrote:

> +  // This function may be called only a small fixed amount of times per
> each
> +  // invocation, otherwise we do actually have a leak which we want to
> report.
> +  // If this function is called more than kGraveYardMaxSize times, the
> pointers
> +  // will not be properly buried and a leak detector will report a leak,
> which
> +  // is what we want in such case.
>

Interesting. I didn't realize it was going to be *that* tightly bounded.

This makes me wonder if the whole disable free thing should just be removed
at this point. Back in the day, we didn't so carefully use a
BumpPtrAllocator in the ASTContext. Today, we might be fine to call free 10
times. Anyways, not trying to shift the goal posts; I mostly wanted to
mention it in case someone gets some time to look into removing all of the
leak stuff.


> +  static const size_t kGraveYardMaxSize = 16;
> +  static const void *GraveYard[kGraveYardMaxSize];
> +  static llvm::sys::cas_flag GraveYardSize;
>

Do these being function-local statics defeat the purpose of using a basic
atomic increment? I can't recall if we correctly eliminate the cxa_guard in
these cases...
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