From d5165908bbdb10e56528ab7042cfd39d4aede72d Mon Sep 17 00:00:00 2001
From: Siddhesh Poyarekar <siddhesh@redhat.com>
Date: Thu, 9 Jul 2026 15:25:40 -0400
Subject: [PATCH] Update prettyprinter update script for incremental GTS diffs

Bump gts_major to 16.  When a previous GTS prettyprinter update exists
in the spec, diff incrementally from the previous GTS revision instead
of from the system revision.  Also fix hardcoded spec filename in the
GitLab URL to use $gts_major.

Related: RHEL-169098

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 update-libstdcxx-prettyprinter.sh | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/update-libstdcxx-prettyprinter.sh b/update-libstdcxx-prettyprinter.sh
index 2e044a1..f508ba1 100755
--- a/update-libstdcxx-prettyprinter.sh
+++ b/update-libstdcxx-prettyprinter.sh
@@ -7,7 +7,7 @@ fi
 
 # Variables to set up for a new GTS update.
 # The latest GTS supported on this branch.
-gts_major=15
+gts_major=16
 # Tests that need to be synced in for this change.  These are required to sync
 # in adjustments to tests due to changes to pretty printer output.
 # Occasionally, a test adjustment may be due to an ABI change, in which case
@@ -32,9 +32,16 @@ branch=`git branch --show-current`
 
 if ! [[ $branch =~ ^c[0-9]+s$ ]]; then echo "Must be run on a valid centos stream branch, not '$branch'"; exit 1; fi
 
-gtsrev=`curl -s https://gitlab.com/redhat/centos-stream/rpms/gcc-toolset-$gts_major-gcc/-/raw/$(git branch --show-current)/gcc-toolset-15-gcc.spec?ref_type=heads | sed -n 's/^%global gitrev //p'`
+gtsrev=`curl -s https://gitlab.com/redhat/centos-stream/rpms/gcc-toolset-$gts_major-gcc/-/raw/$branch/gcc-toolset-$gts_major-gcc.spec?ref_type=heads | sed -n 's/^%global gitrev //p'`
 
-echo "system at $systemrev and GTS at $gtsrev on the vendor branch"
+prev_gts_major=$((gts_major - 1))
+if grep -q "^Patch.*prettyprinter-update-$prev_gts_major" gcc.spec; then
+  baserev=`curl -s https://gitlab.com/redhat/centos-stream/rpms/gcc-toolset-$prev_gts_major-gcc/-/raw/$branch/gcc-toolset-$prev_gts_major-gcc.spec?ref_type=heads | sed -n 's/^%global gitrev //p'`
+  echo "previous GTS $prev_gts_major at $baserev, GTS $gts_major at $gtsrev on the vendor branch"
+else
+  baserev=$systemrev
+  echo "system at $systemrev and GTS $gts_major at $gtsrev on the vendor branch"
+fi
 
 cwd=$PWD
 cleanup() {
@@ -62,14 +69,14 @@ fi
 
 pp_patchfile=gcc$system_major-libstdc++-prettyprinter-update-$gts_major.patch
 tests_patchfile=gcc$system_major-libstdc++-prettyprinter-update-$gts_major-tests.patch
-git fetch -q origin $systemrev $gtsrev
+git fetch -q origin $baserev $gtsrev
 # We limit the update to just the printer, retain the system gcc hook and
 # make-foo.
-git diff --stat --patch $systemrev..$gtsrev -- libstdc++-v3/python/libstdcxx > ../$pp_patchfile
+git diff --stat --patch $baserev..$gtsrev -- libstdc++-v3/python/libstdcxx > ../$pp_patchfile
 echo "Updated $pp_patchfile"
 
 testfiles=$(echo "$tests" | awk '/.+/{printf "libstdc++-v3/testsuite/libstdc++-prettyprinters/%s ", $1}')
-git diff --stat --patch $systemrev..$gtsrev -- $testfiles > ../$tests_patchfile
+git diff --stat --patch $baserev..$gtsrev -- $testfiles > ../$tests_patchfile
 echo "Updated $tests_patchfile"
 
 popd