Add a script to produce combined fuzzing coverage profiles.

cov_profiles.sh

@@ -0,0 +1,68 @@
+#!/bin/bash
+#
+# Fetches coverage data for each fuzz test, combines them, and produces a
+# coverage profile that can be analyzed.
+if [[ "$#" -ne 1 ]]; then
+    echo "Usage: $0 LND_DIR"
+    exit 1
+fi
+
+readonly LND_DIR=$1
+readonly CACHE_DIR=$(mktemp -d)
+
+# Get the directory of cov_profiles.sh in case it is being called not in
+# lnd-fuzz.
+readonly BASE_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+
+readonly packages=("lnwire" "brontide" "htlcswitch/hop" "tlv" "watchtower/wtwire" "watchtower/wtclient" "zpay32") 
+
+# collect_combine_cov_profiles collects coverage for each fuzzing package and
+# then combines them.
+function collect_combine_cov_profiles {
+    local coverage_dirs=()
+
+    # Collect coverage profiles.
+    for p in ${packages[@]}; do
+        cd "${BASE_DIR}/${p}/testdata/fuzz"
+
+        for f in $(ls $PWD); do
+            # Move corpus to CACHE_DIR.
+            mkdir -p "${CACHE_DIR}/${f}"
+            cp -a "${BASE_DIR}/${p}/testdata/fuzz/${f}"/ "${CACHE_DIR}/${f}/"
+            num_inputs=$(ls "${CACHE_DIR}/${f}/" | wc -l | xargs)
+            mkdir -p "${BASE_DIR}/coverage/${f}"
+
+            cd "${LND_DIR}/${p}/"
+
+            go test -v -cover -run="^${f}$" -fuzz="^${f}$" \
+                -fuzztime="${num_inputs}x" \
+                -test.gocoverdir="${BASE_DIR}/coverage/${f}" \
+                -test.fuzzcachedir="${CACHE_DIR}"
+
+            coverage_dirs+=("coverage/${f}")
+        done
+
+        cd $BASE_DIR
+    done
+
+    # Combine coverage profiles.
+    local profile_str=""
+    local coverage_dirs_len=${#coverage_dirs[@]}
+
+    for (( i = 1; i <= $coverage_dirs_len; i++ ))
+    do
+        let "index = $i - 1"
+        if [[ $i -eq $coverage_dirs_len ]]
+        then
+            profile_str+="./${coverage_dirs[$index]}"
+            break
+        fi
+
+        profile_str+="./${coverage_dirs[$index]},"
+    done
+
+    go tool covdata textfmt -i=$profile_str -o coverage/profile
+}
+
+
+collect_combine_cov_profiles