gitconfig: Improve commit-msg hook

[coreboot.git] / util / gitconfig / commit-msg

diff --git a/util/gitconfig/commit-msg b/util/gitconfig/commit-msg
index 789bad382b23c398f0bd74d4f68169f07ed71afd..212ffb1738efeb8c5fc4a015441376897709f8be 100755 (executable)
--- a/util/gitconfig/commit-msg
+++ b/util/gitconfig/commit-msg
@@ -1,5 +1,4 @@
 #!/bin/sh
-# From Gerrit Code Review 2.1.7-rc2
 #
 # Part of Gerrit Code Review (http://code.google.com/p/gerrit/)
 #
@@ -37,56 +36,126 @@ add_ChangeId() {
                return
        fi
 
+       # Does Change-Id: already exist? if so, exit (no change).
        if grep -i '^Change-Id:' "$MSG" >/dev/null
        then
                return
        fi
 
        id=`_gen_ChangeId`
-       perl -e '
-               $MSG = shift;
-               $id = shift;
-               $CHANGE_ID_AFTER = shift;
-
-               undef $/;
-               open(I, $MSG); $_ = <I>; close I;
-               s|^diff --git a/.*||ms;
-               s|^#.*$||mg;
-               exit unless $_;
-
-               @message = split /\n/;
-               $haveFooter = 0;
-               $startFooter = @message;
-               for($line = @message - 1; $line >= 0; $line--) {
-                       $_ = $message[$line];
-
-                       if (/^[a-zA-Z0-9-]+:/ && !m,^[a-z0-9-]+://,) {
-                               $haveFooter++;
-                               next;
-                       }
-                       next if /^[ []/;
-                       $startFooter = $line if ($haveFooter && /^\r?$/);
-                       last;
+       T="$MSG.tmp.$$"
+       AWK=awk
+       if [ -x /usr/xpg4/bin/awk ]; then
+               # Solaris AWK is just too broken
+               AWK=/usr/xpg4/bin/awk
+       fi
+
+       # How this works:
+       # - parse the commit message as (textLine+ blankLine*)*
+       # - assume textLine+ to be a footer until proven otherwise
+       # - exception: the first block is not footer (as it is the title)
+       # - read textLine+ into a variable
+       # - then count blankLines
+       # - once the next textLine appears, print textLine+ blankLine* as these
+       #   aren't footer
+       # - in END, the last textLine+ block is available for footer parsing
+       $AWK '
+       BEGIN {
+               # while we start with the assumption that textLine+
+               # is a footer, the first block is not.
+               isFooter = 0
+               footerComment = 0
+               blankLines = 0
+       }
+
+       # Skip lines starting with "#" without any spaces before it.
+       /^#/ { next }
+
+       # Skip the line starting with the diff command and everything after it,
+       # up to the end of the file, assuming it is only patch data.
+       # If more than one line before the diff was empty, strip all but one.
+       /^diff --git a/ {
+               blankLines = 0
+               while (getline) { }
+               next
+       }
+
+       # Count blank lines outside footer comments
+       /^$/ && (footerComment == 0) {
+               blankLines++
+               next
+       }
+
+       # Catch footer comment
+       /^\[[a-zA-Z0-9-]+:/ && (isFooter == 1) {
+               footerComment = 1
+       }
+
+       /]$/ && (footerComment == 1) {
+               footerComment = 2
+       }
+
+       # We have a non-blank line after blank lines. Handle this.
+       (blankLines > 0) {
+               print lines
+               for (i = 0; i < blankLines; i++) {
+                       print ""
                }
 
-               @footer = @message[$startFooter+1..@message];
-               @message = @message[0..$startFooter];
-               push(@footer, "") unless @footer;
+               lines = ""
+               blankLines = 0
+               isFooter = 1
+               footerComment = 0
+       }
+
+       # Detect that the current block is not the footer
+       (footerComment == 0) && (!/^\[?[a-zA-Z0-9-]+:/ || /^[a-zA-Z0-9-]+:\/\//) {
+               isFooter = 0
+       }
 
-               for ($line = 0; $line < @footer; $line++) {
-                       $_ = $footer[$line];
-                       next if /^($CHANGE_ID_AFTER):/i;
-                       last;
+       {
+               # We need this information about the current last comment line
+               if (footerComment == 2) {
+                       footerComment = 0
                }
-               splice(@footer, $line, 0, "Change-Id: I$id");
+               if (lines != "") {
+                       lines = lines "\n";
+               }
+               lines = lines $0
+       }
 
-               $_ = join("\n", @message, @footer);
-               open(O, ">$MSG"); print O; close O;
-       ' "$MSG" "$id" "$CHANGE_ID_AFTER"
+       # Footer handling:
+       # If the last block is considered a footer, splice in the Change-Id at the
+       # right place.
+       # Look for the right place to inject Change-Id by considering
+       # CHANGE_ID_AFTER. Keys listed in it (case insensitive) come first,
+       # then Change-Id, then everything else (eg. Signed-off-by:).
+       #
+       # Otherwise just print the last block, a new line and the Change-Id as a
+       # block of its own.
+       END {
+               unprinted = 1
+               if (isFooter == 0) {
+                       print lines "\n"
+                       lines = ""
+               }
+               changeIdAfter = "^(" tolower("'"$CHANGE_ID_AFTER"'") "):"
+               numlines = split(lines, footer, "\n")
+               for (line = 1; line <= numlines; line++) {
+                       if (unprinted && match(tolower(footer[line]), changeIdAfter) != 1) {
+                               unprinted = 0
+                               print "Change-Id: I'"$id"'"
+                       }
+                       print footer[line]
+               }
+               if (unprinted) {
+                       print "Change-Id: I'"$id"'"
+               }
+       }' "$MSG" > $T && mv $T "$MSG" || rm -f $T
 }
 _gen_ChangeIdInput() {
        echo "tree `git write-tree`"
-       if parent=`git rev-parse HEAD^0 2>/dev/null`
+       if parent=`git rev-parse "HEAD^0" 2>/dev/null`
        then
                echo "parent $parent"
        fi