Add optional auto parsing printout to InitRootHandlers

[makortel]

PR description:

This PR makes use of the new facility added to ROOT master in root-project/root#18402 to optionally print out the auto-parsed classes from InitRootHandlers. Since the feature is only available in ROOT master, the related code is enclosed in #if on ROOT version.

Context #49458

Resolves cms-sw/framework-team#2132

PR validation:

This printout was useful for #49949 (comment) and #50580 (comment)

[cmsbuild]

cms-bot internal usage

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-50632/48827

[cmsbuild]

A new Pull Request was created by @makortel for master.

It involves the following packages:

• FWCore/Services (core)

@Dr15Jones, @cmsbuild, @makortel, @smuzaffar can you please review it and eventually sign? Thanks.
@fwyzard, @wddgit this is something you requested to watch as well.
@ftenchini, @mandrenguyen, @sextonkennedy you are the release manager for this.

cms-bot commands are listed here

[makortel]

@cmsbuild, please test

[makortel]

@cmsbuild, please test for CMSSW_16_1_ROOT6_X

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-130bc7/52415/summary.html
COMMIT: 33414a8
CMSSW: CMSSW_16_1_ROOT6_X_2026-03-31-2300/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/50632/52415/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 240 lines to the logs
• Reco comparison results: 2027 differences found in the comparisons
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4180749
• DQMHistoTests: Total failures: 20573
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4160156
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 52 files compared)
• Checked 227 log files, 197 edm output root files, 53 DQM output files
• TriggerResults: no differences found

[makortel]

@cmsbuild, please test

[cmsbuild]

+1

Size: This PR adds an extra 20KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-130bc7/52443/summary.html
COMMIT: 33414a8
CMSSW: CMSSW_16_1_X_2026-04-02-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/50632/52443/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 1 lines to the logs
• Reco comparison results: 10 differences found in the comparisons
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4180749
• DQMHistoTests: Total failures: 14
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4180715
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 52 files compared)
• Checked 227 log files, 197 edm output root files, 53 DQM output files
• TriggerResults: no differences found

[cmsbuild]

Milestone for this pull request has been moved to CMSSW_17_0_X. Please open a backport if it should also go in to CMSSW_16_1_X.

[makortel]

Comparison differences are related to #47071

[makortel]

+core

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @mandrenguyen, @sextonkennedy, @ftenchini (and backports should be raised in the release meeting by the corresponding L2)

[mandrenguyen]

+1