Re: make_ctags: use -I option to ignore pg_node_attr macro

>> Attached is the v2 patch.
> 
> Thanks for the patch!
> 
> With the patch, I got the following error when executing make_etags..
> 
> $ ./src/tools/make_etags
> etags: invalid option -- 'e'
>     Try 'etags --help' for a complete list of options.
> sort: No such file or directory

Oops. Thank you for pointing it out. BTW, just out of curiosity, do
you have etags on you Mac? Mine doesn't have etags. That's why I
missed the error.

> +        if [ $? != 0 -a -z "$ETAGS_EXISTS" ]
> + then echo "'ctags' does not support emacs mode and etags does not
> exist" 1>&2; exit 1
> +        fi
> 
> This code can be reached after "rm -f ./$TAGS_FILE" is executed in
> make_ctags.
> But we should check whether the required program has been already
> installed
> and exit immediately if not, before modifying anything?

Agreed.

> This is the comment for the commit d1e2a380cb. I found that make_etags
> with
> an invalid option reported the following usage message mentioning
> make_ctags
> (not make_etags). Isn't this confusing?
> 
> $ ./src/tools/make_etags -a
> Usage: /.../make_ctags [-e][-n]

That's hard to fix without some code duplication. We decided that
make_etags is not a symlink to make_ctags, rather execs make_ctags. Of
course we could let make_etags perform the same option check, but I
doubt it's worth the trouble.

Anyway, attached is the v3 patch.

Best reagards,
--
Tatsuo Ishii
SRA OSS LLC
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp
diff --git a/src/tools/make_ctags b/src/tools/make_ctags
index 102881667b..38f4d8e2d5 100755
--- a/src/tools/make_ctags
+++ b/src/tools/make_ctags
@@ -12,12 +12,15 @@ fi
 MODE=
 NO_SYMLINK=
 TAGS_FILE="tags"
+ETAGS_EXISTS=
+PROG=ctags
 
 while [ $# -gt 0 ]
 do
     if [ $1 = "-e" ]
     then    MODE="-e"
         TAGS_FILE="TAGS"
+        command -v etags >/dev/null && ETAGS_EXISTS="Y"
     elif [ $1 = "-n" ]
     then    NO_SYMLINK="Y"
     else
@@ -27,15 +30,33 @@ do
     shift
 done
 
-command -v ctags >/dev/null || \
+if test -z "$MODE"
+then    (command -v ctags >/dev/null) || \
     { echo "'ctags' program not found" 1>&2; exit 1; }
+fi
 
 trap "ret=$?; rm -rf /tmp/$$; exit $ret" 0 1 2 3 15
-rm -f ./$TAGS_FILE
 
 IS_EXUBERANT=""
 ctags --version 2>&1 | grep Exuberant && IS_EXUBERANT="Y"
 
+# ctags is not exuberant and emacs mode is specified
+if [ -z "$IS_EXUBERANT" -a -n "$MODE" ]
+then
+    if [ -n "$ETAGS_EXISTS" ]
+    then
+        # etags exists. Use it.
+        PROG=etags
+        MODE=
+    else    ctags --help 2>&1 | grep -- -e >/dev/null
+        # Note that "ctags --help" does not always work. Even certain ctags does not have the option.
+        # In that case we assume that the ctags does not support emacs mode.
+        if [ $? != 0 -a -z "$ETAGS_EXISTS" ]
+        then    echo "'ctags' does not support emacs mode and etags does not exist" 1>&2; exit 1
+        fi
+    fi
+fi
+
 # List of kinds supported by Exuberant Ctags 5.8
 # generated by ctags --list-kinds
 # --c-kinds was called --c-types before 2003
@@ -65,11 +86,19 @@ then    IGNORE_IDENTIFIES="-I pg_node_attr+"
 else    IGNORE_IDENTIFIES=
 fi
 
+if [ $PROG = "ctags" ]
+then    TAGS_OPT="-a -f"
+else    TAGS_OPT="-a -o"
+    FLAGS=
+fi
+
+rm -f ./$TAGS_FILE
+
 # this is outputting the tags into the file 'tags', and appending
 find `pwd`/ \( -name tmp_install -prune -o -name tmp_check -prune \) \
     -o \( -name "*.[chly]" -o -iname "*makefile*" -o -name "*.mk" -o -name "*.in" \
     -o -name "*.sql" -o -name "*.p[lm]" \) -type f -print |
-    xargs ctags $MODE -a -f $TAGS_FILE "$FLAGS" "$IGNORE_IDENTIFIES"
+    xargs $PROG $MODE $TAGS_OPT $TAGS_FILE "$FLAGS" "$IGNORE_IDENTIFIES"
 
 # Exuberant tags has a header that we cannot sort in with the other entries
 # so we skip the sort step