🍒 [-Wunsafe-buffer-usage] Check count-attributed objects that are used and assigned in the same group #11753
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…and assigned in the same group
Check if the bounds-attributed group has assignments to objects that are
also used in the same group. In those cases, the correctness of the
group might depend on the order of assignments. We conservatively
disallow such assignments.
In the example below, the bounds-check in `sp.first()` uses the value of
`b` before the later update, which can lead to OOB if `b` was less than
42.
```
void foo(int *__counted_by(a + b) p, int a, int b, std::span<int> sp) {
p = sp.first(b + 42).data();
b = 42; // b is assigned and used
a = b;
}
```
rdar://161608319
(cherry picked from commit 7e4ad9d)
patrykstefanski
added
the
clang:bounds-safety
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@swift-ci test |
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@swift-ci test llvm |
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@swift-ci test macOS platform |
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Check if the bounds-attributed group has assignments to objects that are also used in the same group. In those cases, the correctness of the group might depend on the order of assignments. We conservatively disallow such assignments.
In the example below, the bounds-check in
sp.first()uses the value ofbbefore the later update, which can lead to OOB ifbwas less than 42.rdar://161608319
(cherry picked from commit 7e4ad9d)