From 3049f0c7aa4ba48f57e9538b3cd07e1c519d340d Mon Sep 17 00:00:00 2001
From: Henner Zeller <h.zeller@acm.org>
Date: Tue, 11 Mar 2025 17:05:56 -0700
Subject: [PATCH] Make run-clang-format.sh work well in before-submit and CI

In scripts/before-submit.sh, we do not want to get an error
when anything is formatted, we just want it to be done.

In the CI, however, we want to use the same script and have it
fail if not.
---
 .github/workflows/ci.yml    | 16 ++--------------
 scripts/run-clang-format.sh | 27 ++++++++++++++++-----------
 2 files changed, 18 insertions(+), 25 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index fbb68dd..77e176b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -67,19 +67,8 @@ jobs:
       - name: Run formatting style check
         run: |
           clang-format-18 --version
-          CLANG_FORMAT=clang-format-18 scripts/run-clang-format.sh
-          git diff > /tmp/format-diff
-          if [ -s "/tmp/format-diff" ]; then
-            echo "Difference to optimal formatting"
-            cat /tmp/format-diff
-            echo
-            echo "=================== To Fix ==========================="
-            echo "Run scripts/run-format.sh"
-            echo "then"
-            echo "  git commit -a --amend"
-            echo "  git push -f"
-            exit 1
-          fi
+          RUNNING_IN_CI=1 CLANG_FORMAT=clang-format-18 \
+            scripts/run-clang-format.sh
 
   ClangTidy:
     runs-on: ubuntu-24.04
@@ -117,4 +106,3 @@ jobs:
           clang-tidy-18 --version
           CLANG_TIDY=clang-tidy-18 scripts/run-clang-tidy-cached.cc \
             || ( cat fpga-assembler_clang-tidy.out ; exit 1)
-
diff --git a/scripts/run-clang-format.sh b/scripts/run-clang-format.sh
index 5862cdb..bd387d1 100755
--- a/scripts/run-clang-format.sh
+++ b/scripts/run-clang-format.sh
@@ -6,6 +6,7 @@ FORMAT_OUT=${TMPDIR:-/tmp}/clang-format-diff.out
 
 CLANG_FORMAT=${CLANG_FORMAT:-clang-format}
 BUILDIFIER=${BUILDIFIER:-buildifier}
+RUNNING_IN_CI=${RUNNING_IN_CI:-0}
 
 ${CLANG_FORMAT} --version
 
@@ -19,17 +20,21 @@ if command -v ${BUILDIFIER} >/dev/null; then
   ${BUILDIFIER} -lint=fix MODULE.bazel $(find . -name BUILD -o -name "*.bzl")
 fi
 
-# Check if we got any diff
-git diff > ${FORMAT_OUT}
-
-if [ -s ${FORMAT_OUT} ]; then
-   echo "Style not matching"
-   echo "Run"
-   echo "  .github/bin/run-clang-format.sh"
-   echo "-------------------------------------------------"
-   echo
-   cat ${FORMAT_OUT}
-   exit 1
+# If in CI, we want to report changes, as we don't expect them
+if [ "$RUNNING_IN_CI" -eq 1 ]; then
+    # Check if we got any diff
+    git diff > ${FORMAT_OUT}
+
+    if [ -s ${FORMAT_OUT} ]; then
+	echo "Style not matching"
+	echo "Run"
+	echo "  scripts/run-clang-format.sh"
+	echo "and amend PR."
+	echo "-------------------------------------------------"
+	echo
+	cat ${FORMAT_OUT}
+	exit 1
+    fi
 fi
 
 exit 0