[PATCH] D97924: [LangRef] clarify the semantics of nocapture

[Juneyoung Lee via Phabricator via llvm-commits]

aqjune marked an inline comment as done.
aqjune added a comment.

I updated this patch to address comments & added a few examples that I concern.
I hope this helps check whether my understanding about pointer capture is correct.



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Comment at: llvm/docs/LangRef.rst:1206
-    attribute for return values.  Addresses used in volatile operations
-    are considered to be captured.
 
----------------
I moved the volatile thing to the new section.


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Comment at: llvm/docs/LangRef.rst:2647
+A pointer that is passed as a :ref:`nocapture <nocapture>` argument isn't
+escaped by the function call.
+
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jdoerfert wrote:
> The first thing is not true, e.g., it ignores ptr2int.
Thank you. For correctness & clarity, I removed the paragraph.


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Comment at: llvm/docs/LangRef.rst:2653
+and another not tagged as arguments, and callee can escape the untagged
+pointer.
+
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jdoerfert wrote:
> I honestly don't understand this. For me, the beginning reads like: "If the pointer is nocapture it is captured when ...." which is at least odd. I assume you want to say that nocapture applies to the use and not the value, if so, let's do that more explicitly.
Yes, your understanding is right. I added a relevant example with `nocapture` at the nocapture paragraph.


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