Commit Graph

4 Commits

Author SHA1 Message Date
Adrian Prantl
053d7cf277 Debug Info: Don't emit shadow stack copies for local variables.
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>
2016-03-08 11:10:02 -08:00
Xin Tong
6d006adbcc Revert "Debug Info: Don't emit shadow stack copies for local variables."
This reverts commit 1cb9c24b2f.

Broke OSX incremental build and others.
2016-03-02 07:55:33 -08:00
Adrian Prantl
1cb9c24b2f Debug Info: Don't emit shadow stack copies for local variables.
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>
2016-03-01 18:47:34 -08:00
Adrian Prantl
f1315f8b5c Debug Info: Make sure to enter a new SILDebugScope before generating
weak copies for capture list variables. Other wise two variables with
identical names will end up in the same scope.

This fixes a crash in the compiler.

rdar://problem/24150188
SR-526
2016-01-20 15:20:51 -08:00