[PATCH] D144337: Prevent line 0 instructions from dividing a lexical block into ranges

[David Blaikie via Phabricator via llvm-commits]

dblaikie added a comment.

> No, my intent was not to use UnknownLocations as a proxy for CV, but I think it is safe not to fold line 0 instructions into a scope range when UnknownLocations is enabled. AFAIK, when UnknownLocations is enabled line 0 entries are emitted in the debug information. In my opinion, Folding these instructions when the switch is enabled could break stuff.

Yeah, I'm still really not following this. `UnknownLocations` isn't the only source of zero lines (I think the most obvious/easy example is, if I recall correctly, line zero is used for merged function calls). And even if it was, I don't understand why it would need to be tested in LexicalScopes.cpp where the line can be tested for zero directly, right? So why do we need to test anything else other than that it's line zero?


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  https://reviews.llvm.org/D144337/new/

https://reviews.llvm.org/D144337