Also, add a third [serializable] state for functions whose bodies we
*can* serialize, but only do so if they're referenced from another
serialized function.
This will be used for bodies synthesized for imported definitions,
such as init(rawValue:), etc, and various thunks, but for now this
change is NFC.
The effect of this tiny change is that local variables will be described
by llvm.dbg.values, which will get lowered into an accurate location list
instead of a stack slot that is valid for the entire scope of the variable.
This means the debugger can now accurately track the liveness of variables
knowing exactly when they are initialized and when there values go away.
Function arguments are still kept in stack slots because (1) they are
already initialized at the function entry and (2) LLDB really needs self
to be available at all times for the expression evaluator.
This was made possible by recent advancements in LLVM such as the live
debug variables pass and various related bugfixes.
<rdar://problem/15746520>
The effect of this tiny change is that local variables will be described
by llvm.dbg.values, which will get lowered into an accurate location list
instead of a stack slot that is valid for the entire scope of the variable.
This means the debugger can now accurately track the liveness of variables
knowing exactly when they are initialized and when there values go away.
Function arguments are still kept in stack slots because (1) they are
already initialized at the function entry and (2) LLDB really needs self
to be available at all times for the expression evaluator.
This was made possible by recent advancements in LLVM such as the live
debug variables pass and various related bugfixes.
<rdar://problem/15746520>
Having a separate address and container value returned from alloc_stack is not really needed in SIL.
Even if they differ we have both addresses available during IRGen, because a dealloc_stack is always dominated by the corresponding alloc_stack in the same function.
Although this commit quite large, most changes are trivial. The largest non-trivial change is in IRGenSIL.
This commit is a NFC regarding the generated code. Even the generated SIL is the same (except removed #0, #1 and @local_storage).
This allows SIL transformations to describe one source variable with more
than one debug_value instruction.
rdar://problem/22705966
(cherry picked from commit fd6e8a9bef)
