From f07e60916d938d0d3a6d0f074b3c4d06b56af822 Mon Sep 17 00:00:00 2001
From: rillig <rillig@pkgsrc.org>
Date: Sat, 5 Jan 2008 17:55:48 +0000
Subject: Rewrote the help parser. You can get a list of all help topics by
 running "bmake help topic=:index" now. This change is in preparation of
 importing this help into the pkgsrc guide. There are still too many false
 positives to be useful.

---
 mk/help/help.awk | 90 ++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 61 insertions(+), 29 deletions(-)

(limited to 'mk')

diff --git a/mk/help/help.awk b/mk/help/help.awk
index ba20c582206..a953d111eaa 100644
--- a/mk/help/help.awk
+++ b/mk/help/help.awk
@@ -1,4 +1,4 @@
-# $NetBSD: help.awk,v 1.19 2008/01/05 17:01:23 rillig Exp $
+# $NetBSD: help.awk,v 1.20 2008/01/05 17:55:48 rillig Exp $
 #
 
 # This program extracts the inline documentation from *.mk files.
@@ -15,50 +15,67 @@ BEGIN {
 
 	found_anything = no;	# has some help text been found at all?
 	last_fname = "";
-	this_line_maybe_definition = yes;
 	ignore_this_line = no;
 	ignore_next_empty_line = no;
+	ignore_this_section = no;
 
 	delete lines;		# the collected lines
 	nlines = 0;		# the number of lines collected so far
 	delete keywords;	# the keywords for this paragraph
+	delete all_keywords;	# all keywords that appear anywhere
 	comment_lines = 0;	# the number of comment lines so far
 	print_noncomment_lines = yes; # for make targets, this isn't useful
+	print_index = (topic == ":index");
+				# whether to print only the list of keywords
 }
 
 # Help topics are separated by either completely empty lines or by the
 # end of a file or by the end of all files. When there have been enough
 # comment lines, the topic is considered worth printing.
 #
-function end_of_topic(		kw, relevant) {
-	kw = "";
-	for (i in keywords) {
-		kw = kw " " i;
+function end_of_topic() {
+
+	if (comment_lines <= 2 || ignore_this_section) {
+		cleanup();
+		return;
 	}
+
+	for (k in keywords)
+		all_keywords[k]++;
+
 	relevant = (topic in keywords || lctopic in keywords || uctopic in keywords);
-	if (relevant && comment_lines > 2) {
+	if (relevant && !print_index) {
+
 		if (found_anything)
 			print "";
 		found_anything = yes;
+
+		kw = "";
+		for (i in keywords)
+			kw = kw " " i;
 		print "===> "last_fname " (keywords:" kw "):";
+
 		for (i = 0; i < nlines; i++) {
 			if (print_noncomment_lines || (lines[i] ~ /^#/))
 				print lines[i];
 		}
 	}
+	cleanup();
+}
 
+function cleanup() {
 	ignore_next_empty_line = yes;
 	delete lines;
 	nlines = 0;
 	delete keywords;
 	comment_lines = 0;
 	print_noncomment_lines = yes;
+	ignore_this_section = no;
 }
 
 always {
 	ignore_this_line = (ignore_next_empty_line && $0 == "#") || $0 == "";
 	ignore_next_empty_line = no;
-	this_line_is_definition = no;
 }
 
 # There is no need to print the RCS Id, since the full pathname
@@ -86,6 +103,10 @@ always {
 	ignore_next_empty_line = no;
 }
 
+$1 == "#" && $2 == "Copyright" {
+	ignore_this_section = yes;
+}
+
 # Don't show the user the definition of make targets, since they are
 # usually not interesting enough. This allows the comments to reach
 # until the line directly above the target definition.
@@ -102,30 +123,38 @@ $1 ~ /:$/ && $2 == ".PHONY" {
 # be all-lowercase (make targets) or all-uppercase (variable names).
 # Everything else is assumed to belong to the explaining text.
 #
-NF >= 1 {
+NF >= 1 && !/^[\t.]/ && !/^#*$/ {
+	w = $1 == "#" ? $2 : $1;
+
 	# Reduce FOO.<param> and FOO.${param} to FOO.
-	w1 = $1; sub(/\.[<$].*[>}]$/, "", w1);
-	w2 = $2; sub(/\.[<$].*[>}]$/, "", w2);
-
-	# Convert all-lowercase words to all-uppercase.
-	w1 = (w1 == tolower(w1)) ? toupper(w1) : w1;
-	w2 = (w2 == tolower(w2)) ? toupper(w2) : w2;
-
-	this_line_is_definition = (w1 == toupper($1)) && (w2 == toupper($2));
-
-	w = (w1 == "#") ? w2 : w1;
-	if ((w1 == uctopic"?=") ||
-	    (w1 == uctopic"=") ||
-	    (index(w1, "#"uctopic"=") == 1) ||
-	    (index(w1, "#"uctopic"?=") == 1) ||
-	    (this_line_maybe_definition &&
-	        (w == uctopic || w == uctopic":"))) {
-		keywords[w] = yes;
+	sub(/\.[<$].*[>}]$/, "", w);
+
+	if (w ~ /\+=$/) {
+		# Appending to a variable is usually not a definition.
+
+	} else if (!(w == toupper(w)) || (w == tolower(w) && w ~ /:$/)) {
+		# Automatic keywords must be either upper- or lower-case.
+		# Lower-case keywords (make targets) must end with a colon.
+
+	} else if (w !~ /^[A-Za-z].*[0-9A-Za-z]$/) {
+		# Keywords must start with a letter and end with a letter
+		# or digit.
+
+	} else if (w ~ /^(FIXME|TODO|XXX):?$/) {
+		# These are not keywords.
+
+	} else {
+		sub(/^#[ \t]*/, "", w);
+		sub(/\??=.*$/, "", w);
+		sub(/:$/, "", w);
+		if (w != "") {
+			keywords[w] = yes;
+		}
 	}
 }
 
 # Don't print the implementation of make targets.
-$1 == uctopic":" {
+$1 ~ /:$/ {
 	print_noncomment_lines = no;
 }
 
@@ -139,13 +168,16 @@ $1 == "#" {
 
 always {
 	# Note: The first "this" actually means the next line.
-	this_line_maybe_definition = (/^#$/ || /^$/) || this_line_is_definition;
 	last_fname = FILENAME;
 }
 
 END {
 	end_of_topic();
-	if (!found_anything) {
+	if (print_index) {
+		for (k in all_keywords) {
+			print all_keywords[k] "\t" k;
+		}
+	} else if (!found_anything) {
 		print "No help found for "topic".";
 	}
 }
-- 
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