feat: enhance util/check-format-commit.sh to be able to handle a commit range

Additionally, the 'git diff' call is modified to not show context lines, as
it's confusing to have style nits displayed on lines the author of the
commits hasn't touched.

Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/24856)

diff --git a/util/check-format-commit.sh b/util/check-format-commit.sh
index 835645131b6cd4fd7fcca1b31a94d9142b2a9ef7..9e22bb1227a0d8c0d54ffdd724838181ff3d0acc 100755 (executable)
--- a/util/check-format-commit.sh
+++ b/util/check-format-commit.sh
@@ -6,10 +6,10 @@
 # You can obtain a copy in the file LICENSE in the source distribution
 # or at https://www.openssl.org/source/license.html
 #
-# This script is a wrapper around check-format.pl.  It accepts a commit sha
-# value as input, and uses it to identify the files and ranges that were
-# changed in that commit, filtering check-format.pl output only to lines that
-# fall into the commits change ranges.
+# This script is a wrapper around check-format.pl.  It accepts the same commit
+# revision range as 'git diff' as arguments, and uses it to identify the files
+# and ranges that were changed in that range, filtering check-format.pl output
+# only to lines that fall into the change ranges of the changed files.
 #
 
 
@@ -54,10 +54,11 @@ cleanup() {
 
 trap cleanup EXIT
 
-# Get the canonical sha256 sum for the commit we are checking
+# Get the canonical sha256 sum for the commits we are checking
 # This lets us pass in symbolic ref names like master/etc and 
 # resolve them to sha256 sums easily
-COMMIT=$(git rev-parse $1)
+COMMIT_RANGE="$@"
+COMMIT_LAST=$(git rev-parse $COMMIT_RANGE)
 
 # Fail gracefully if git rev-parse doesn't produce a valid
 # commit
@@ -67,11 +68,24 @@ then
     exit 1
 fi
 
-# Create a iteratable list of files to check for a
-# given commit. It produces output of the format
-# <commit id> <file name> <change start line>, <change line count>
+# If the commit range was just one single revision, git rev-parse
+# will output jut commit id of that one alone.  In that case, we
+# must manipulate a little to get a desirable result, 'cause git
+# diff has a slightly different interpretation of a single commit
+# id, and takes that to mean all commits up to HEAD.
+if [ $(echo "$COMMIT_LAST" | wc -l) -gt 1 ]; then
+    COMMIT_LAST=$(echo "$COMMIT_LAST" | head -1)
+else
+    # $COMMIT_RANGE is just one commit, make it an actual range
+    COMMIT_RANGE=$COMMIT_RANGE^..$COMMIT_RANGE
+fi
+
+# Create an iteratable list of files to check formatting on,
+# including the line ranges that are changed by the commits
+# It produces output of this format:
+# <file name> <change start line>, <change line count>
 touch $TEMPDIR/ranges.txt
-git show $COMMIT | awk -v mycmt=$COMMIT '
+git diff -U0 $COMMIT_RANGE | awk '
     BEGIN {myfile=""} 
     /+{3}/ {
         gsub(/b\//,"",$2);
@@ -79,7 +93,7 @@ git show $COMMIT | awk -v mycmt=$COMMIT '
     }
     /@@/ {
         gsub(/+/,"",$3);
-        printf mycmt " " myfile " " $3 "\n"
+        printf myfile " " $3 "\n"
     }' >> $TEMPDIR/ranges.txt || true
 
 # filter out anything that matches on a filter regex
@@ -102,20 +116,15 @@ done
 # to $TEMPDIR/check-format.  This give us the full file to run
 # check-format.pl on with line numbers matching the ranges in the
 # $TEMPDIR/ranges.txt file
-for j in $(grep $COMMIT $TEMPDIR/ranges.txt | awk '{print $2}')
+for j in $(cat $TEMPDIR/ranges.txt | awk '{print $1}' | sort | uniq)
 do
     FDIR=$(dirname $j)
     mkdir -p $TEMPDIR/check-format/$FDIR
-    git show $COMMIT:$j > $TEMPDIR/check-format/$j
+    git show $COMMIT_LAST:$j > $TEMPDIR/check-format/$j
 done
 
-# Now for each file in $TEMPDIR/check-format run check-format.pl
-# Note that we use the %P formatter in the find utilty.  This strips
-# off the $TEMPDIR/check-format path prefix, leaving $j with the
-# path to the file relative to the root of the source dir, so that 
-# output from check-format.pl looks correct, relative to the root
-# of the git tree.
-for j in $(find $TEMPDIR/check-format -type f -printf "%P\n")
+# Now for each file in $TEMPDIR/ranges.txt, run check-format.pl
+for j in $(cat $TEMPDIR/ranges.txt | awk '{print $1}' | sort | uniq)
 do
     range_start=()
     range_end=()
@@ -125,7 +134,7 @@ do
     # contains the corresponding end line (note, since diff output gives us
     # a line count for a change, the range_end[k] entry is actually
     # range_start[k]+line count
-    for k in $(grep $COMMIT $TEMPDIR/ranges.txt | grep $j | awk '{print $3}')
+    for k in $(grep ^$j $TEMPDIR/ranges.txt | awk '{print $2}')
     do
         RANGE=$k
         RSTART=$(echo $RANGE | awk -F',' '{print $1}')