GV

GeezerVison

The World Wide Web, restored to 800 pixels of glory.

Home|About|Gaming cabinet|Archives|How it works|Starter sites

On this site

  • Sign in
  • ActionsCI/CD and automation
  • CodespacesCloud development environments
  • All Features
  • Documentation
  • Training
  • Certifications
  • Build with Copilot
  • Customize Copilot
  • Integrations
  • Trending repos
  • GitHub Sponsors
  • Developer articles
  • Enterprises

This view

  • Original page
  • New address

GeezerVison is showing github.com — gh-148832: Use `-icf=0` in BOLT_APPLY_FLAGS by ashm-dev · Pull Request #148833 · python/cpython

Conversation

@ashm-dev

@ashm-dev ashm-dev commented Apr 21, 2026 •
edited by bedevere-app Bot
Loading

Uh oh!

There was an error while loading. Please reload this page.

Copy link
Copy Markdown
Contributor
  • Issue: Build: BOLT -icf=1 breaks type-slot function-pointer identity, causes SIGSEGV #148832

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
All reactions
@ashm-dev
Use -icf=safe in BOLT_APPLY_FLAGS
5735919
@ashm-dev
ashm-dev requested review from AA-Turner, corona10, emmatyping and erlend-aasland as code owners April 21, 2026 14:25
@bedevere-app bedevere-app Bot added the awaiting review label Apr 21, 2026
@bedevere-app bedevere-app Bot mentioned this pull request Apr 21, 2026
Build: BOLT -icf=1 breaks type-slot function-pointer identity, causes SIGSEGV #148832
Closed
ashm-dev added 3 commits April 21, 2026 17:28
@ashm-dev
Add blurb
5c89a9a
@ashm-dev
Merge branch 'main' into bolt-icf-safe
fbd2b22
@ashm-dev
Use -icf=0 for older BOLT compatibility
0b0404a
@ashm-dev ashm-dev changed the title gh-148832: Use -icf=safe in BOLT_APPLY_FLAGS gh-148832: Use -icf=0 in BOLT_APPLY_FLAGS Apr 21, 2026
@corona10 corona10 self-assigned this Apr 22, 2026
@ashm-dev
Merge branch 'main' into bolt-icf-safe
5252c6d
@ashm-dev

ashm-dev commented Apr 29, 2026

Copy link
Copy Markdown
Contributor Author

@corona10 @erlend-aasland could you please review this PR?
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@ashm-dev

ashm-dev commented May 19, 2026

Copy link
Copy Markdown
Contributor Author

Gentle ping — this is a small, low-risk build-flag change (-icf=0 in BOLT_APPLY_FLAGS) that's been awaiting review for ~4 weeks. @AA-Turner @emmatyping you were both auto-requested as reviewers — would either of you have a moment to take a look?
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@ankhikarmakar ankhikarmakar mentioned this pull request May 19, 2026
BOLT-WARNING: specifying numeric value "1" for option -icf is deprecated #149708
Open
ashm-dev and others added 2 commits May 24, 2026 20:50
@ashm-dev
Merge branch 'main' into bolt-icf-safe
253ce71
@corona10
Merge branch 'main' into bolt-icf-safe
cd77df8
@corona10
corona10 requested a review from itamaro as a code owner June 6, 2026 06:41
corona10
corona10 approved these changes Jun 6, 2026
View reviewed changes

@corona10 corona10 left a comment

Copy link
Copy Markdown
Member

There was a problem hiding this comment.

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

lgtm!

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
ashm-dev reacted with thumbs up emoji
All reactions
  • 👍 1 reaction
@bedevere-app bedevere-app Bot added awaiting merge and removed awaiting review labels Jun 6, 2026
@corona10
corona10 enabled auto-merge (squash) June 6, 2026 06:41
@corona10
corona10 merged commit 2452449 into python:main Jun 6, 2026
134 of 138 checks passed

Uh oh!

There was an error while loading. Please reload this page.
@bedevere-app bedevere-app Bot removed the awaiting merge label Jun 6, 2026
@ashm-dev
ashm-dev deleted the bolt-icf-safe branch June 6, 2026 08:49
philthompson10 pushed a commit to philthompson10/cpython that referenced this pull request Jun 17, 2026
@ashm-dev @philthompson10
pythongh-148832: Use -icf=0 in BOLT_APPLY_FLAGS (pythongh-148833)
988c367
@geofft

geofft commented Sep 11, 2026

Copy link
Copy Markdown
Contributor

FYI I totally forgot about this until just now but #134642 uses -icf=safe on LLVM versions that support it (LLVM 20 and up) and leaves the flag out entirely on older versions. Safe ICF doesn't run into the issue with function pointer equality. Do we need to explicitly set -icf=0 instead of leaving the flag out? I think it's off by default.
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@ashm-dev

ashm-dev commented Sep 11, 2026

Copy link
Copy Markdown
Contributor Author

@geofft AFAIK it's off by default. If you believe leaving it out causes regressions on older LLVM builds, please feel free to verify against the BOLT docs and provide a test case.
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@geofft

geofft commented Sep 11, 2026

Copy link
Copy Markdown
Contributor

No, I believe leaving it out is plenty, just wanted to confirm (since the current behavior / the behavior in this PR is to explicitly say -icf=0).
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@ashm-dev

ashm-dev commented Sep 11, 2026

Copy link
Copy Markdown
Contributor Author

No, I believe leaving it out is plenty, just wanted to confirm (since the current behavior / the behavior in this PR is to explicitly say -icf=0).

PRs welcome. Unsubscribing from this thread.
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@geofft geofft mentioned this pull request Sep 14, 2026
gh-101525: Use only safe identical code folding with BOLT #134642
Open
@Aplietexe Aplietexe mentioned this pull request Oct 17, 2026
[3.15] gh-148832: Use -icf=0 in BOLT_APPLY_FLAGS (GH-148833) Aplietexe/cpython#1
Open
Aplietexe pushed a commit to Aplietexe/cpython that referenced this pull request Oct 18, 2026
@ashm-dev @Aplietexe
[3.15] pythongh-148832: Use -icf=0 in BOLT_APPLY_FLAGS (pythonGH-14…
36e7c0b 
…8833)

(cherry picked from commit 2452449)
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@corona10 corona10 corona10 approved these changes
@erlend-aasland erlend-aasland Awaiting requested review from erlend-aasland erlend-aasland is a code owner
@AA-Turner AA-Turner Awaiting requested review from AA-Turner AA-Turner is a code owner
@emmatyping emmatyping Awaiting requested review from emmatyping emmatyping is a code owner
@itamaro itamaro Awaiting requested review from itamaro itamaro is a code owner

Uh oh!

There was an error while loading. Please reload this page.

Assignees

@corona10 corona10

Labels

None yet

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

Uh oh!

There was an error while loading. Please reload this page.

3 participants

@ashm-dev @geofft @corona10
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
You are visitor 01402503 — GeezerVison does not store the pages you look up.
Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.