tree 20fe8b32c4f7a1b62853c6f6d68f813f2810a25d
parent f547046850010e726dc179340fcc8b7b5c470155
author Than McIntosh <thanm@google.com> 1592846775 -0400
committer Than McIntosh <thanm@google.com> 1592999876 +0000

[dev.link] cmd/{compile,link}: fix file/line of last instruction in DWARF line table

The code in the compiler's DWARF line table generation emits line
table ops at the end of each function fragment to reset the state
machine registers back to an initial state, so that when the line
table fragments for each function are stitched together into a
compilation unit, each fragment will have a clean starting point. The
set-file/set-line ops emitted in this code were being applied to the
last row of the line table, however, meaning that they were
overwriting the existing values.

To avoid this problem, add code to advance the PC past the end of the
last instruction in the function, and switch to just using an
end-of-sequence operator at the end of each function instead of
explicit set-file/set-line ops.

Updates #39757.

Change-Id: Ieb30f83444fa86fb1f2cd53862d8cc8972bb8763
Reviewed-on: https://go-review.googlesource.com/c/go/+/239286
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: David Chase <drchase@google.com>