[PATCH] D70539: [clang][CodeGen] Implicit Conversion Sanitizer: handle increment/derement (PR44054)

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added inline comments.


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Comment at: clang/lib/CodeGen/CGExprScalar.cpp:2424
+        type->isPromotableIntegerType()) {
+      // While `x += 1` (for `x` with width less than int) is modelled as
+      // promotion+arithmetics+demotion, and we can catch lossy demotion with
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modelled -> modeled


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Comment at: clang/lib/CodeGen/CGExprScalar.cpp:2428
+      // promotion rules, so we omit promotion+demotion, which means that we can
+      // not catch lossy "demotion". Since we still want to catch those cases,
+      // if the sanitizer is enabled, let's perform the promotion, perform
----------------
lebedev.ri wrote:
> erichkeane wrote:
> > comma at the end here isn't required.  The one after 'enabled' needs to be a semicolon I think?
> > comma at the end here isn't required.
> Right.
> 
> > The one after 'enabled' needs to be a semicolon I think?
> It doesn't look like that to me?
> 
> 
I'd reword it to make the problem go away. :-D
```
Because we still want to catch these cases when the sanitizer is enabled, we perform the promotion, then perform the increment/decrement in the wider type, and finally perform the demotion. This will catch lossy demotions.
```


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D70539/new/

https://reviews.llvm.org/D70539