[Lldb-commits] [PATCH] D53662: Give the SymbolFile plugin enough information to efficiently do exact match lookups

[Jim Ingham via Phabricator via lldb-commits]

jingham added a comment.

Exact matches aren't a C++ specific thing.  An exact match is useful for mixed C/C++ since you might want to say Foo and not Bar::Foo.  IIRC a couple of the places where exact was dialed up explicitly in FindTypes were for C types.   But since C and ObjC allow multiple types with the same name, that's one way you might see multiple matches for "exact match".  Moreover C+ used to be fuzzy about whether non-exported classes from different linkage uses had to follow the ODR.  I haven't followed whether this got nailed down but it still seems Quixotic to expect you could enforce this, since you are asking two totally unrelated library vendors to avoid each other's names for private classes...  So having several classes with the same name is still a possibility IRL with C++.

Why we care is that if somebody runs the command:

(lldb) expression (::SomeClass *) 0x12345

We're going to try our best to make that work.  If SomeClass is not visible in the module/comp_unit/function in which we are currently stopped, then we will go looking far and wide for SomeClass.  If we find one result somewhere out in the world, the expression will succeed, but if we find two results which are different, then we want to give an error about ambiguous type.


https://reviews.llvm.org/D53662