36 Commits

Author SHA1 Message Date
Kazu Hirata
63e059de23
[llvm] Proofread *.rst (#168185)
This patch is limited to single-word replacements to fix spelling
and/or grammar to ease the review process.  Punctuation and markdown
fixes are specifically excluded.
2025-11-15 08:06:23 -08:00
Kazu Hirata
183b38078a
[llvm] Proofread *.rst (#151087)
This patch hyphenates words that are used as adjecives, such as:

- architecture specific
- human readable
- implementation defined
- language independent
- language specific
- machine readable
- machine specific
- target independent
- target specific
2025-08-01 07:01:50 -07:00
Stephen Tozer
b7c14b6ded
[Debugify] Add 'acceptance-test' mode for the debugify report script (#147574)
For the purposes of setting up CI that makes use of debugify, this patch
adds an alternative mode for the llvm-original-di-preservation.py
script, which produces terminal-friendly(-ish) YAML output instead of an
HTML report, and sets the return code to 1 if the input file contains
errors, or 0 if the input file contains no errors or does not exist,
making it simple to use it in CI.

This introduces a small change in existing usage, in that the path for
the HTML report file is now passed with `--report-file <path>` rather
than as a positional argument; I could make the argparse logic work
without this change, but I believe that is simpler to understand this
way, and to my knowledge debugify isn't currently being used in
automated environments where changing this might cause issues. As a
small change while passing by, I also changed `-compress` to
`--compress`, for consistency.

As a note for reviewers, the reason that we treat a non-existent input
file as a pass is that this is actually the expected state: we use clang
to compile numerous files, passing a filepath for debugify errors. Any
errors found by debugify will be written to this file; if none are
found, the file is untouched. This is also mentioned in a code comment,
but I think it useful to state upfront.

Finally, the justification for adding a new mode to this script instead
of adding a separate script for the separate functionality is that this
script understands debugify's output, and performs some deduplication
that is useful for clarifying the resulting output. Writing a new script
would require duplicating logic unnecessarily, and risks the scripts
falling out-of-sync if changes are made to debugify's output.
2025-07-17 11:40:43 +01:00
Orlando Cazalet-Hyams
9eb0fc8e57 Fix link in docs after #137991 2025-07-15 13:50:15 +01:00
Orlando Cazalet-Hyams
acffe8324b
[KeyInstr] Add docs (#137991)
This document explains the core ideas and some implementation details
of the Key Instructions project. The LLVM document also outlines the two
main limitations of our approach.

RFC:
https://discourse.llvm.org/t/rfc-improving-is-stmt-placement-for-better-interactive-debugging/82668
2025-07-15 13:38:08 +01:00
Stephen Tozer
a34b1755e2
[DLCov] Origin-Tracking: Add debugify support (#143594)
This patch is part of a series that adds origin-tracking to the debugify
source location coverage checks, allowing us to report symbolized stack
traces of the point where missing source locations appear.

This patch completes the feature, having debugify handle origin stack
traces by symbolizing them when an associated bug is found and printing
them into the JSON report file as part of the bug entry. This patch also
updates the script that parses the JSON report and creates a
human-readable HTML report, adding an "Origin" entry to the table that
contains an expandable textbox containing the symbolized stack trace.
2025-07-04 09:52:12 +01:00
Stephen Tozer
92195f6fc8 Reapply "[DLCov] Implement DebugLoc coverage tracking (#107279)"
Reapplied after fixing the config issue that was causing issues following
the previous merge.

This reverts commit fdbf073a86573c9ac4d595fac8e06d252ce1469f.
2025-04-30 11:39:29 +01:00
Stephen Tozer
fdbf073a86 Revert "[DLCov] Implement DebugLoc coverage tracking (#107279)"
This reverts commit a9d93ecf1f8d2cfe3f77851e0df179b386cff353.

Reverted due to the commit including a config in LLVM headers that is not
available outside of the llvm source tree.
2025-04-25 00:36:28 +01:00
Stephen Tozer
a9d93ecf1f
[DLCov] Implement DebugLoc coverage tracking (#107279)
This is part of a series of patches that tries to improve DILocation bug
detection in Debugify; see the review for more details. This is the patch
that adds the main feature, adding a set of `DebugLoc::get<Kind>`
functions that can be used for instructions with intentionally empty
DebugLocs to prevent Debugify from treating them as bugs, removing the
currently-pervasive false positives and allowing us to use Debugify (in
its original DI preservation mode) to reliably detect existing bugs and
regressions. This patch does not add uses of these functions, except for
once in Clang before optimizations, and in
`Instruction::dropLocation()`, since that is an obvious case that
immediately removes a set of false positives.
2025-04-24 19:41:25 +01:00
Snehasish Kumar
f9193f3b18
[DebugInfo] Preserve line and column number when merging debug info. (#129960)
This patch introduces a new option `-preserve-merged-debug-info` to
preserve an arbitrary but deterministic version of debug information
when DILocations are merged. This is intended to be used in production
environments from which sample based profiles are derived such as
AutoFDO and MemProf.

With this patch we have see a 0.2% improvement on an internal workload
at Google when generating AutoFDO profiles. It also significantly
improves the ability for MemProf by preserving debug info for merged
call instructions used in the contextual profile.

---------

Co-authored-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
2025-04-04 09:37:25 -07:00
Stephen Tozer
6d23ac1aa2
[DebugInfo] Update policy for when to merge locations (#115349)
Following discussions on PR #114231 this patch changes the policy on
merging locations, making the rule that new instructions should use a
merge of the locations of all the instructions whose output is produced
by the new instructions; in the case where only one instruction's output
is produced, as in most InstCombine optimizations, we use only that
instruction's location.
2024-11-12 09:16:59 +00:00
Shan Huang
ac93554462
Refine the examples in the debug info document (#86272)
This PR modifies the examples of section "When to merge instruction
locations" in
[HowToUpdateDebugInfo](https://llvm.org/docs/HowToUpdateDebugInfo.html)
according to [the
discussion](https://discourse.llvm.org/t/debuginfo-merging-instruction-locations-of-hoisted-instructions/77357),
revise one misleading counterexample and refining the description of
hoisting identical instructions.
2024-09-09 13:49:38 +08:00
Stephen Tozer
400d4fd7b6
[RemoveDIs] Update all docs to use debug records (#91768)
As we approach the state where support for debug intrinsics is dropping and
we print and use debug records by default, the documentation should be updated
to refer to debug records as the primary debug info representation, with
debug intrinsics being relegated to an optional alternative.

This patch performs a few updates:
- Replace references to intrinsics with references to records across all
the documentation.
- Replace intrinsics with records in code examples.
- Move debug records prior to debug intrinsics in the
SourceLevelDebugging document, and change text to refer to them as the
primary representation.
- Add release notes describing the change.
2024-06-11 14:16:32 +01:00
OCHyams
33c7ae55e7 [Assignment Tracking][1/*] Add initial docs for Assignment Tracking
The Assignment Tracking debug-info feature is outlined in this RFC:

https://discourse.llvm.org/t/
  rfc-assignment-tracking-a-better-way-of-specifying-variable-locations-in-ir

Add documentation outlining the intent and design.
2022-11-02 13:47:50 +00:00
Nikola Tesic
c5600aef88 [Debugify] Limit number of processed functions for original mode
Debugify in OriginalDebugInfo mode, does (DebugInfo) collect-before-pass & check-after-pass
for each instruction, which is pretty expensive. When used to analyze DebugInfo losses
in large projects (like LLVM), this raises the build time unacceptably.
This patch introduces a limit for the number of processed functions per compile unit.
By default, the limit is set to UINT_MAX (practically unlimited), and by using the introduced
option  -debugify-func-limit  the limit could be set to any positive integer number.

Differential revision: https://reviews.llvm.org/D115714
2022-04-21 13:58:17 +02:00
Djordje Todorovic
b9076d119a Recommit: "[Debugify][Original DI] Test dbg var loc preservation""
[Debugify][Original DI] Test dbg var loc preservation

    This is an improvement of [0]. This adds checking of
    original llvm.dbg.values()/declares() instructions in
    optimizations.

    We have picked a real issue that has been found with
    this (actually, picked one variable location missing
    from [1] and resolved the issue), and the result is
    the fix for that -- D100844.

    Before applying the D100844, using the options from [0]
    (but with this patch applied) on the compilation of GDB 7.11,
    the final HTML report for the debug-info issues can be found
    at [1] (please scroll down, and look for
    "Summary of Variable Location Bugs"). After applying
    the D100844, the numbers has improved a bit -- please take
    a look into [2].

    [0] https://llvm.org/docs/HowToUpdateDebugInfo.html#\
        test-original-debug-info-preservation-in-optimizations
    [1] https://djolertrk.github.io/di-check-before-adce-fix/
    [2] https://djolertrk.github.io/di-check-after-adce-fix/

    Differential Revision: https://reviews.llvm.org/D100845

The Unit test was failing because the pass from the test that
modifies the IR, in its runOnFunction() didn't return 'true',
so the expensive-check configuration triggered an assertion.
2021-05-21 02:04:29 -07:00
Djordje Todorovic
0ae3c1d4d7 Revert "[Debugify][Original DI] Test dbg var loc preservation"
This reverts commit 76f375f3d9d6902820ffc21200e454926748c678.

This will be pushed again, after investigating a test failure:
https://lab.llvm.org/buildbot/#/builders/16/builds/11254
2021-05-20 07:11:35 -07:00
Djordje Todorovic
76f375f3d9 [Debugify][Original DI] Test dbg var loc preservation
This is an improvement of [0]. This adds checking of
original llvm.dbg.values()/declares() instructions in
optimizations.

We have picked a real issue that has been found with
this (actually, picked one variable location missing
from [1] and resolved the issue), and the result is
the fix for that -- D100844.

Before applying the D100844, using the options from [0]
(but with this patch applied) on the compilation of GDB 7.11,
the final HTML report for the debug-info issues can be found
at [1] (please scroll down, and look for
"Summary of Variable Location Bugs"). After applying
the D100844, the numbers has improved a bit -- please take
a look into [2].

[0] https://llvm.org/docs/HowToUpdateDebugInfo.html\
[1] https://djolertrk.github.io/di-check-before-adce-fix/
[2] https://djolertrk.github.io/di-check-after-adce-fix/

Differential Revision: https://reviews.llvm.org/D100845
2021-05-20 06:42:02 -07:00
Djordje Todorovic
8420a53324 [Debugify] Expose original debug info preservation check as CC1 option
In order to test the preservation of the original Debug Info metadata
in your projects, a front end option could be very useful, since users
usually report that a concrete entity (e.g. variable x, or function fn2())
is missing debug info. The [0] is an example of running the utility
on GDB Project.

This depends on: D82546 and D82545.

Differential Revision: https://reviews.llvm.org/D82547
2021-03-25 05:29:42 -07:00
Djordje Todorovic
9f41c03f82 [Debugify][OriginalDIMode] Export the report into JSON file
By using the original-di check with debugify in the combination with
the llvm/utils/llvm-original-di-preservation.py it becomes very user
friendly tool. An example of the HTML page with the issues
related to debug info can be found at [0].

[0] https://djolertrk.github.io/di-checker-html-report-example/

Differential Revision: https://reviews.llvm.org/D82546
2021-03-11 01:11:13 -08:00
Djordje Todorovic
1a2b3536ef Reland "[Debugify] Make the debugify aware of the original (-g) Debug Info"
As discussed on the RFC [0], I am sharing the set of patches that
    enables checking of original Debug Info metadata preservation in
    optimizations. The proof-of-concept/proposal can be found at [1].

    The implementation from the [1] was full of duplicated code,
    so this set of patches tries to merge this approach into the existing
    debugify utility.

    For example, the utility pass in the original-debuginfo-check
    mode could be invoked as follows:

      $ opt -verify-debuginfo-preserve -pass-to-test sample.ll

    Since this is very initial stage of the implementation,
    there is a space for improvements such as:
      - Add support for the new pass manager
      - Add support for metadata other than DILocations and DISubprograms

    [0] https://groups.google.com/forum/#!msg/llvm-dev/QOyF-38YPlE/G213uiuwCAAJ
    [1] https://github.com/djolertrk/llvm-di-checker

    Differential Revision: https://reviews.llvm.org/D82545

The test that was failing is now forced to use the old PM.
2021-02-18 23:29:22 -08:00
Djordje Todorovic
c1e23894fc Revert "[Debugify] Make the debugify aware of the original (-g) Debug Info"
This reverts rG8ee7c7e02953.
One test is failing, I'll reland this as soon as possible.
2021-02-18 02:04:27 -08:00
Djordje Todorovic
8ee7c7e029 [Debugify] Make the debugify aware of the original (-g) Debug Info
As discussed on the RFC [0], I am sharing the set of patches that
enables checking of original Debug Info metadata preservation in
optimizations. The proof-of-concept/proposal can be found at [1].

The implementation from the [1] was full of duplicated code,
so this set of patches tries to merge this approach into the existing
debugify utility.

For example, the utility pass in the original-debuginfo-check
mode could be invoked as follows:

  $ opt -verify-debuginfo-preserve -pass-to-test sample.ll

Since this is very initial stage of the implementation,
there is a space for improvements such as:
  - Add support for the new pass manager
  - Add support for metadata other than DILocations and DISubprograms

[0] https://groups.google.com/forum/#!msg/llvm-dev/QOyF-38YPlE/G213uiuwCAAJ
[1] https://github.com/djolertrk/llvm-di-checker

Differential Revision: https://reviews.llvm.org/D82545
2021-02-18 01:52:16 -08:00
Florian Hahn
d98fc62ae6 [SimplifyCFG] Keep !dgb metadata of moved instruction, if they match.
Currently SimplifyCFG drops the debug locations of 'bonus' instructions.
Such instructions are moved before the first branch. The reason for the
current behavior is that this could lead to surprising debug stepping,
if the block that's folded is dead.

In case the first branch and the instructions to be folded have the same
debug location, this shouldn't be an issue and we can keep the debug
location.

Reviewed By: vsk

Differential Revision: https://reviews.llvm.org/D93662
2021-01-09 19:15:16 +00:00
Xiang1 Zhang
39584ae5b5 [Debugify] Support checking Machine IR debug info
Add mir-check-debug pass to check MIR-level debug info.

For IR-level, currently, LLVM have debugify + check-debugify to generate
and check debug IR. Much like the IR-level pass debugify, mir-debugify
inserts sequentially increasing line locations to each MachineInstr in a
Module, But there is no equivalent MIR-level check-debugify pass, So now
we support it at "mir-check-debug".

Reviewed By: djtodoro

Differential Revision: https://reviews.llvm.org/D91595
2020-12-16 22:17:25 -08:00
Xiang1 Zhang
1e42ad9d62 Revert "[Debugify] Support checking Machine IR debug info"
This reverts commit 50aaa8c274910d78d7bf6c929a34fe58b1f45579.
2020-12-16 20:12:33 -08:00
Xiang1 Zhang
50aaa8c274 [Debugify] Support checking Machine IR debug info
Add mir-check-debug pass to check MIR-level debug info.

For IR-level, currently, LLVM have debugify + check-debugify to generate
and check debug IR. Much like the IR-level pass debugify, mir-debugify
inserts sequentially increasing line locations to each MachineInstr in a
Module, But there is no equivalent MIR-level check-debugify pass, So now
we support it at "mir-check-debug".

Reviewed By: djtodoro

Differential Revision: https://reviews.llvm.org/D91595
2020-12-16 18:04:05 -08:00
Nico Weber
da2551f3d1 Revert "[Debugify] Support checking Machine IR debug info"
This reverts commit c4d2d4337d50bed3cafd564daece1a197005b22b.
Necessary to revert 2a5675f11d3bc803a245c0e.
2020-12-14 22:14:48 -05:00
Xiang1 Zhang
c4d2d4337d [Debugify] Support checking Machine IR debug info
Add mir-check-debug pass to check MIR-level debug info.

For IR-level, currently, LLVM have debugify + check-debugify to generate
and check debug IR. Much like the IR-level pass debugify, mir-debugify
inserts sequentially increasing line locations to each MachineInstr in a
Module, But there is no equivalent MIR-level check-debugify pass, So now
we support it at "mir-check-debug".

Reviewed By: djtodoro

Differential Revision: https://reviews.llvm.org/D91595
2020-12-14 17:53:46 -08:00
Xiang1 Zhang
fc0f4010bb Revert "[Debugify] Support checking Machine IR debug info"
This reverts commit 57a3d9ec4a8c1422f07264bed9f12a4ea416707e.
2020-12-14 17:48:49 -08:00
Xiang1 Zhang
57a3d9ec4a [Debugify] Support checking Machine IR debug info
Add mir-check-debug pass to check MIR-level debug info.

For IR-level, currently, LLVM have debugify + check-debugify to generate
and check debug IR. Much like the IR-level pass debugify, mir-debugify
inserts sequentially increasing line locations to each MachineInstr in a
Module, But there is no equivalent MIR-level check-debugify pass, So now
we support it at "mir-check-debug".

Reviewed By: djtodoro

Differential Revision: https://reviews.llvm.org/D95195
2020-12-14 17:38:01 -08:00
Vedant Kumar
f71849c74e [docs] Recommend dropLocation() over setDebugLoc(DebugLoc()) 2020-09-29 17:07:14 -07:00
Vedant Kumar
d65cdb498f [docs] Fix typo 2020-06-24 11:51:21 -07:00
Vedant Kumar
b4459b597a [docs] Specify rules for updating debug locations
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
2020-06-18 14:05:45 -07:00
Vedant Kumar
24660ea11c [docs] HowToUpdateDebugInfo: Minor cleanups
- 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.
2020-06-04 14:56:01 -07:00
Vedant Kumar
b429a0fef0 [docs] Sketch outline for HowToUpdateDebugInfo.rst
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
2020-06-01 16:45:18 -07:00