Commit Graph

4 Commits

Author SHA1 Message Date
Balazs Benics 91c07eb8ee [analyzer] Ignore single element arrays in getStaticSize() conditionally
Quoting https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html:
> In the absence of the zero-length array extension, in ISO C90 the contents
> array in the example above would typically be declared to have a single
> element.

We should not assume that the size of the //flexible array member// field has
a single element, because in some cases they use it as a fallback for not
having the //zero-length array// language extension.
In this case, the analyzer should return `Unknown` as the extent of the field
instead.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D108230
2021-09-04 10:19:57 +02:00
Balazs Benics e5646b9254 Revert "Revert "[analyzer] Ignore IncompleteArrayTypes in getStaticSize() for FAMs""
This reverts commit df1f4e0cc6.

Now the test case explicitly specifies the target triple.
I decided to use x86_64 for that matter, to have a fixed
bitwidth for `size_t`.

Aside from that, relanding the original changes of:
https://reviews.llvm.org/D105184
2021-08-25 17:19:06 +02:00
Balazs Benics df1f4e0cc6 Revert "[analyzer] Ignore IncompleteArrayTypes in getStaticSize() for FAMs"
This reverts commit 360ced3b8f.
2021-08-25 16:43:25 +02:00
Balazs Benics 360ced3b8f [analyzer] Ignore IncompleteArrayTypes in getStaticSize() for FAMs
Currently only `ConstantArrayType` is considered for flexible array
members (FAMs) in `getStaticSize()`.
However, `IncompleteArrayType` also shows up in practice as FAMs.

This patch will ignore the `IncompleteArrayType` and return Unknown
for that case as well. This way it will be at least consistent with
the current behavior until we start modeling them accurately.

I'm expecting that this will resolve a bunch of false-positives
internally, caused by the `ArrayBoundV2`.

Reviewed By: ASDenysPetrov

Differential Revision: https://reviews.llvm.org/D105184
2021-08-25 16:12:17 +02:00