Summary:
Restructure HowToUpdateDebugInfo.rst to specify rules for when
transformations should preserve, merge, or drop debug locations.
The goal is to have clear, well-justified rules that come with a few
examples and counter-examples, so that pass authors can pick the best
strategy for managing debug locations depending on the specific task at
hand.
I've tried to set down sensible rules here that mostly align with what
we already do in llvm today, and that take a diverse set of use cases
into account (interactive debugging, crash triage, SamplePGO).
Please *do* try to pick these rules apart and suggest clarifications or
improvements :).
Side note: Prior to 24660ea1, this document was structured as a long
list of very specific code transformations -- the idea being that we
would fill in what to do in each specific case. I chose to reorganize
the document as a list of actions to take because it drastically cuts
down on the amount of redundant exposition/explanation needed. I hope
that's fine...
Reviewers: jmorse, aprantl, dblaikie
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81198
- Change the reference to salvageDebugInfoOrUndef to salvageDebugInfo
(in accordance with https://reviews.llvm.org/D78369).
- Reorganize a few sections in preparation for an upcoming change that
attempts to specify rules for updating debug locations.
- Fix some intra-document links.
- Some spelling / wording fixes.
Summary:
Sketch the outline for a new document that explains how to update debug
info in various kinds of code transformations.
Some of the guidelines that belong in HowToUpdateDebugInfo.rst were in
SourceLevelDebugging.rst already under the debugify section. It seems
like the distinction between the two docs ought to be that the former is
more prescriptive, while the latter is more descriptive.
To that end I've consolidated the "how to update debug info" guidelines
which were in SourceLevelDebugging.rst into the new doc, along with the
information about using "debugify" to test transformations. Since we've
added a mir-debugify pass, I've described that as well.
Reviewers: aprantl, jmorse, chrisjackson, dsanders
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80052
Vedant Kumar