[PATCH] D58694: LLVM: Optimization Pass: Function Attribute: Fix error caused by adding incompactible attribute to WriteOnly attribute of pointer argument

[Johannes Doerfert via Phabricator via llvm-commits]

jdoerfert added inline comments.


================
Comment at: llvm/lib/Transforms/IPO/FunctionAttrs.cpp:730
+            (A->materialized_use_empty())) {
+          A->removeAttr(Attribute::WriteOnly);
+        } else {
----------------
anhtuyen wrote:
> jdoerfert wrote:
> > In general, I dislike specialization for write-only in the first place. If that is voted in, we should make at least the reasoning more explicit: Initializing `R` with readnon above is hard to follow. It should be placed inside this conditional instead.
> Hi @jdoerfert , will you like it better if I move the code to handle **writeonly** (and additionally **readonly**) to inside the function **determinePointerReadAttrs** ?
I prefer replacing all the code, see D59918 and D59980.

For now, I'd argue wherever we have something like
`A->addAttr(R);`
we should remove conflicting arguments.

So make a function, say `addReadAttr(AttrKind R)`, 
which (1) removes conflicting attributes, (2) adds the new attribute, and (3) does the bookkeping (statistics).


Repository:
  rL LLVM

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  https://reviews.llvm.org/D58694/new/

https://reviews.llvm.org/D58694