Adrian Prantl d6200f6d89 Let replaceVTableHolder accept any type.
In Rust, a trait can be implemented for any type, and if a trait
object pointer is used for the type, then a virtual table will be
emitted for that trait/type combination.

We would like debuggers to be able to inspect trait objects, which
requires finding the concrete type associated with a given vtable.

This patch changes LLVM so that any type can be passed to
replaceVTableHolder. This allows the Rust compiler to emit the needed
debug info -- associating a vtable with the concrete type for which it
was emitted.

This is a DWARF extension: DWARF only specifies the meaning of
DW_AT_containing_type in one specific situation. This style of DWARF
extension is routine, though, and LLVM already has one such case for
DW_AT_containing_type.

Patch by Tom Tromey!

Differential Revision: https://reviews.llvm.org/D39503

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317730 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-08 22:04:43 +00:00
..
2017-05-18 11:29:41 +00:00