check-last-commit: more detailed advice on using clang-format

Change-Id: I7e25acd02573c3e173eccefe9326dc42e2940f05
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/146688
Tested-by: Jenkins
Tested-by: Ilmari Lauhakangas <ilmari.lauhakangas@libreoffice.org>
Reviewed-by: Ilmari Lauhakangas <ilmari.lauhakangas@libreoffice.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/solenv/clang-format/check-last-commit b/solenv/clang-format/check-last-commit
index 0de5ac4b0783..bd26258c5ad4 100755
--- a/solenv/clang-format/check-last-commit
+++ b/solenv/clang-format/check-last-commit
@@ -65,7 +65,11 @@ sub check_style()
     {
         print("\nERROR: The above differences were found between the code to commit \n");
         print("and the clang-format rules. Tips:\n");
-        print("\n- You may run '/opt/lo/bin/clang-format -i <problematic file>' to fix up style automatically.\n");
+        print("\n- On your local machine you may check how clang-format would modify the problematic file by saying\n");
+        print("  diff --unified <problematic file> <(/opt/lo/bin/clang-format <problematic file>)\n");
+        print("- NOTE: you should only correct the lines that you changed. Do not add unrelated formatting to your patch.\n");
+        print("- If the suggested corrections only apply to the lines you changed, you may run\n");
+        print("  '/opt/lo/bin/clang-format -i <problematic file>' to fix up style automatically.\n");
         print("- See solenv/clang-format/README on where to get the required version of clang-format binaries.\n");
         print("- If you renamed an excluded file, update solenv/clang-format/excludelist accordingly to keep it excluded.\n");
         print("\nsolenv/clang-format/check-last-commit: KO\n");