From 9054ca14ca29b2819630dd2a3b3ac4795566f593 Mon Sep 17 00:00:00 2001
From: Eugene Siegel <elzeigel@gmail.com>
Date: Tue, 8 Oct 2024 06:32:31 -0400
Subject: [PATCH] Add a script to produce combined fuzzing coverage profiles.

---
 cov_profiles.sh | 66 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100755 cov_profiles.sh

diff --git a/cov_profiles.sh b/cov_profiles.sh
new file mode 100755
index 00000000..7deb382c
--- /dev/null
+++ b/cov_profiles.sh
@@ -0,0 +1,66 @@
+#!/bin/bash
+#
+# Fetches coverage data for each fuzz test, combines them, and produces a
+# coverage profile that can be analyzed.
+
+set -e
+
+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 ${PACKAGES[@]}; do
+        pushd "${BASE_DIR}/${p}/testdata/fuzz"
+
+        for f in $(ls $PWD); do
+            # Copy corpus to CACHE_DIR.
+            mkdir -p "${CACHE_DIR}/${f}"
+            cp -a "${BASE_DIR}/${p}/testdata/fuzz/${f}"/ "${CACHE_DIR}/${f}/"
+            num_inputs=$(find "${CACHE_DIR}/${f}/" -maxdepth 1 -type f | wc -l | tr -d '[:space:]')
+            mkdir -p "${BASE_DIR}/coverage/${f}"
+
+            pushd "${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}")
+
+            popd
+        done
+
+        popd
+    done
+
+    # Combine coverage profiles.
+    local profile_str=""
+    local coverage_dirs_len=${#coverage_dirs[@]}
+
+    for ((i = 0; i < coverage_dirs_len - 1; i++)); do
+    profile_str+="./${coverage_dirs[$i]},"
+        done
+    profile_str+="./${coverage_dirs[coverage_dirs_len-1]}"
+
+    go tool covdata textfmt -i=$profile_str -o coverage/profile
+}
+
+
+collect_combine_cov_profiles