[PATCH] D75695: [StackProtector] Catch direct out-of-bounds when checking address-takenness

[John Brawn via Phabricator via llvm-commits]

john.brawn marked an inline comment as done.
john.brawn added inline comments.


================
Comment at: llvm/lib/CodeGen/StackProtector.cpp:197-198
+      // object.
+      Type *ToType = I->getType()->getPointerElementType();
+      Type *FromType = I->getOperand(0)->getType()->getPointerElementType();
+      if (DL.getTypeAllocSize(ToType) > DL.getTypeAllocSize(FromType))
----------------
arsenm wrote:
> This is introducing new dependences on the deprecated pointee type. No decisions should be made based on this
I don't see anything in Type.h about getPointerElementType being deprecated, but looking at Instructions.h I see mention of "opaque pointer types", is this what you're talking about? Looking at http://lists.llvm.org/pipermail/llvm-dev/2019-December/137684.html (which is the best I could find for what it means) it looks like instead of

```
%var = alloca i32, align 4
%bitcast = i32* %var to %i64
store i64 0, i32* %bitcast
```
we'll have
```
%var = alloca i32, align 4
store i64 0, p0 %var
```
So it looks like I should be checking the type at the load/store instead?


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  https://reviews.llvm.org/D75695/new/

https://reviews.llvm.org/D75695