[PATCH] D69664: [Diagnostics] Teach -Wnull-dereference about address_space attribute

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman accepted this revision.
aaron.ballman added a comment.
This revision is now accepted and ready to land.

LGTM with a testing request.



================
Comment at: clang/lib/Sema/SemaExpr.cpp:486
     if (UO->getOpcode() == UO_Deref &&
-        UO->getSubExpr()->IgnoreParenCasts()->
-          isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull) &&
+        !isTargetAddressSpace(
+            UO->getSubExpr()->getType()->getPointeeType().getAddressSpace()) &&
----------------
xbolva00 wrote:
> With this patch, we no longer warn for:
> 
> *(int __attribute__((address_space(0))) *) 0;
> 
> Worth to handle this case?
I mildly think it would be useful to warn in that case, but I'm fine with that being done later.


================
Comment at: clang/test/Sema/exprs.c:190
+   *(int_AS256*)0 = 0; // Ok.
 
   // rdar://9269271
----------------
Can you add a test case for dereferencing for a read instead of a write, just to ensure we don't diagnose that case?

You may want to add the `address_space(0)` test case as well, with a FIXME that it should warn at some point.


Repository:
  rG LLVM Github Monorepo

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