Fixing up make html target

Add types of files that genhtml (the program that generates html files
from .gcno/.gcda files, included in lcov) should ignore, such as .yy and
.ll files.

testing/coverage/Makefile

@@ -9,7 +9,4 @@ distclean: cleanup
 	@find ../../ -name "*.gcno" -exec rm {} \;
 
 html:
-	@(cd ../../; if which lcov; then\
+	@./lcov_html.sh $(COVERAGE_HTML_DIR)
-		lcov --capture --directory . --output-file coverage.info \
-		&& genhtml coverage.info && rm coverage.info; \
-	fi)

testing/coverage/README

@@ -2,12 +2,7 @@ On a Bro build configured with --enable-coverage, this script produces a code co
 
 This depends on gcov, which should come with your gcc. If gcov is not installed, the script will abort with an error message.
 
-TODO: Use `make html` as make target in this directory to output the html files that gcov can create (must have lcov on system).
+After `make all` in the upper directory, use `make html` as make target in this directory to output the html files that lcov can create. By default, the html files will be contained in a directory named "coverage-html" in the base directory. To set a custom name, use `make html COVERAGE_HTML_DIR=custom-dir-name`.
 
-The goal of code-coverage.sh script is to automate code coverage testing. See the following steps for the code structure:
+The script code_coverage.sh is triggered by `make coverage` (included in `make` in /testing), and its goal is to automate code coverage testing. 
-	1. Run test suite
+The script lcov_html.sh is triggered by `make html`, and its goal is to create html files from the aforementioned coverage data.
- 	2. Check for .gcda files existing.
-	3a. Run gcov (-p to preserve path)
-	3b. Prune .gcov files for objects outside of the Bro tree
-	4a. Analyze .gcov files generated and create summary file
-	4b. Send .gcov files to appropriate path

testing/coverage/code_coverage.sh

@@ -17,13 +17,12 @@
 #	4b. Send .gcov files to appropriate path
 #
 CURR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )" # Location of script
-BASE="$(readlink -f "${CURR}/../../")"
+BASE="$( cd "$CURR" && cd ../../ && pwd )"
 TMP="${CURR}/tmp.$$"
 mkdir -p $TMP
 
 # DEFINE CLEANUP PROCESS
 function finish {
-	find "$BASE" -name "*.gcda" -exec rm {} \; > /dev/null 2>&1
 	rm -rf $TMP
 }
 trap finish EXIT
@@ -98,13 +97,20 @@ echo "ok"
 # 3a. Run gcov (-p to preserve path) and move into tmp directory
 # ... if system does not have gcov installed, exit with message.
 echo -n "Creating coverage files... "
-if which gcov; then
+if which gcov > /dev/null 2>&1; then
 	( cd "$TMP" && find "$BASE" -name "*.o" -exec gcov -p {} > /dev/null 2>&1 \; )
 	NUM_GCOVS=$(find "$TMP" -name *.gcov | wc -l)
 	if [ $NUM_GCOVS -eq 0 ]; then
 		echo "no gcov files produced, aborting"
 		exit 1
 	fi
+
+	# Account for '^' that occurs in macOS due to LLVM
+	# This character seems to be equivalent to ".." (up 1 dir)
+	for file in $(ls $TMP/*.gcov | grep '\^'); do
+		mv $file "$(sed 's/#[^#]*#\^//g' <<< "$file")"
+	done
+
 	echo "ok, $NUM_GCOVS coverage files"
 else
 	echo "gcov is not installed on system, aborting"

testing/coverage/lcov_html.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+#
+# On a Bro build configured with --enable-coverage, this script
+# produces a code coverage report in HTML format after Bro has been invoked. The
+# intended application of this script is after the btest testsuite has run.
+
+# This depends on lcov to run.
+
+function die {
+	echo "$@"
+	exit 1
+}
+function finish {
+	rm -rf "$TMP"
+}
+function verify-run {
+	if bash -c "$1" > /dev/null 2>&1; then
+		echo ${2:-"ok"}
+	else
+		die ${3:-"error, abort"}
+	fi
+}
+trap finish EXIT 
+
+COVERAGE_FILE="./$TMP/coverage.info"
+COVERAGE_HTML_DIR="${1:-"coverage-html"}"
+REMOVE_TARGETS="*.yy *.ll *.y *.l"
+
+# 1. Move to base dir, create tmp dir
+cd ../../; 
+TMP=".tmp.$$"
+mkdir "$TMP"
+
+# 2. Check for .gcno and .gcda file presence
+echo -n "Checking for coverage files... "
+for pat in gcda gcno; do
+    if [ -z "$(find "$BASE" -name "*.$pat" 2>/dev/null)" ]; then
+        echo "no .$pat files, nothing to do"
+	exit 0
+    fi
+done
+echo "ok"
+
+# 3. If lcov does not exist, abort process. 
+echo -n "Checking for lcov... "
+verify-run "which lcov" \
+	"lcov installed on system, continue" \
+	"lcov not installed, abort"
+
+# 4. Create a "tracefile" through lcov, which is necessary to create html files later on.
+echo -n "Creating tracefile for html generation... " 
+verify-run "lcov --no-external --capture --directory . --output-file $COVERAGE_FILE"
+
+for TARGET in $REMOVE_TARGETS; do
+	echo -n "Getting rid of $TARGET files from tracefile... "
+	verify-run "lcov --remove $COVERAGE_FILE $TARGET --output-file $COVERAGE_FILE"
+done
+
+# 5. Create HTML files. 
+echo -n "Creating HTML files... "
+verify-run "genhtml -q -o $COVERAGE_HTML_DIR $COVERAGE_FILE"