[PATCH] D80317: [SYCL] Prohibit arithmetic operations for incompatible pointers

[Anastasia Stulova via Phabricator via cfe-commits]

Anastasia added subscribers: jeroen.dobbelaere, rjmccall.
Anastasia added inline comments.


================
Comment at: clang/lib/Sema/SemaExpr.cpp:10090
   // if both are pointers check if operation is valid wrt address spaces
-  if (S.getLangOpts().OpenCL && isLHSPointer && isRHSPointer) {
+  if ((S.getLangOpts().OpenCL || S.getLangOpts().SYCLIsDevice) &&
+      isLHSPointer && isRHSPointer) {
----------------
bader wrote:
> Alternative approach would be to remove `S.getLangOpts().OpenCL` to enable this check for all modes.
> 
> @Anastasia, do you know if it's safe to do?
If I look at embedded C (ISO/IEC TR 18037) s5.3 rules that we are following largely in Clang I believe this is a universal rule!

Especially looking at the followong statement:

> Clause 6.5.6 - Additive operators, add another constraint paragraph: 
> For subtraction, if the two operands are pointers into different address spaces, the address spaces must overlap. 

So I think that it should apply to at least OpenCL, C and C++.  I am surprised though that this has not been fixed yet.

I am CCing @rjmccall and @jeroen.dobbelaere in case they have any more insights on this.



Repository:
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  https://reviews.llvm.org/D80317/new/

https://reviews.llvm.org/D80317