From 9ce1329ff1e87e6f05f764b4b659207391f4d183 Mon Sep 17 00:00:00 2001
From: filipecosta90 <filipecosta.90@gmail.com>
Date: Tue, 5 Apr 2022 14:47:39 +0100
Subject: [PATCH 1/3] Kicking off fuzz testing with libfuzzer

---
 CMakeLists.txt       |  1 +
 Makefile             |  1 +
 tests/CMakeLists.txt | 15 +++++++++++++++
 tests/test_fuzzer.cc | 10 ++++++++++
 4 files changed, 27 insertions(+)
 create mode 100644 tests/test_fuzzer.cc

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2c24767..264271b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -12,6 +12,7 @@ option(BUILD_BENCHMARK "Build benchmark" ON)
 option(BUILD_TESTS "Build tests" ON)
 OPTION(ENABLE_CODECOVERAGE "Enable code coverage testing support" OFF)
 OPTION(ENABLE_PROFILE "Enable code profiling support" OFF)
+option(ENABLE_FUZZER "Enable fuzz testing" OFF)
 option(BUILD_EXAMPLES "Build examples" ON)
 
 # --- Build properties ---
diff --git a/Makefile b/Makefile
index db8f06a..3bc9cf0 100644
--- a/Makefile
+++ b/Makefile
@@ -77,6 +77,7 @@ ifndef CMAKE_TEST_OPTIONS
 	CMAKE_TEST_OPTIONS=\
 		-DBUILD_SHARED=ON \
 		-DBUILD_STATIC=ON \
+		-DENABLE_FUZZER=ON \
 		-DBUILD_TESTS=ON \
 		-DENABLE_CODECOVERAGE=ON \
 		-DBUILD_BENCHMARK=OFF \
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 5163a06..a24686c 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -18,3 +18,18 @@ add_executable(td_test td_test.c minunit.h)
 target_link_libraries(td_test tdigest m)
 enable_testing()
 add_test(td_test td_test)
+
+
+# --- Fuzz testing ---
+if (ENABLE_FUZZER)
+  message(STATUS "Forcing compiler to be clang given we're using libfuzz.")
+  set(CMAKE_C_COMPILER clang)
+  set(CMAKE_CXX_COMPILER clang)
+  add_executable(td_fuzz test_fuzzer.cc)
+  target_compile_options(td_fuzz PRIVATE $<$<C_COMPILER_ID:Clang>:-g -O1
+                                          -fsanitize=fuzzer>)
+
+  target_link_libraries(td_fuzz
+                        PRIVATE $<$<C_COMPILER_ID:Clang>:-fsanitize=fuzzer> tdigest)
+  add_test(td_fuzz td_fuzz)
+endif()
diff --git a/tests/test_fuzzer.cc b/tests/test_fuzzer.cc
new file mode 100644
index 0000000..8b83386
--- /dev/null
+++ b/tests/test_fuzzer.cc
@@ -0,0 +1,10 @@
+// Test_fuzzer.cc
+#include <stdint.h>
+#include <stddef.h>
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  if (size > 0 && data[0] == 'H')
+    if (size > 1 && data[1] == 'I')
+       if (size > 2 && data[2] == '!')
+       __builtin_trap();
+  return 0;
+}
\ No newline at end of file

From 736fbce8a4259cd6dc4893c26129fe8e65f1cda2 Mon Sep 17 00:00:00 2001
From: filipecosta90 <filipecosta.90@gmail.com>
Date: Tue, 5 Apr 2022 14:50:28 +0100
Subject: [PATCH 2/3] circleci fix apt update

---
 .circleci/config.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6d1e489..540f90c 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -19,7 +19,7 @@ jobs:
       - checkout
       - run:
           name: Install CMAKE
-          command: 'apt install -y cmake'
+          command: 'apt install -y cmake --fix-missing'
       - run:
           name: Pull Submodules
           command: git submodule update --init --recursive

From 8e894e03a56486ee69aa30079e4120705725e52d Mon Sep 17 00:00:00 2001
From: filipecosta90 <filipecosta.90@gmail.com>
Date: Tue, 5 Apr 2022 14:56:17 +0100
Subject: [PATCH 3/3] using silkeh/clang:12

---
 .circleci/config.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 540f90c..c4b2ce9 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -4,7 +4,7 @@ version: 2.1
 jobs:
   lint:
     docker:
-      - image: redislabsmodules/llvm-toolset:latest
+      - image: silkeh/clang:12
     steps:
       - checkout
       - run:
@@ -14,7 +14,7 @@ jobs:
 
   sanitize:
     docker:
-      - image: redislabsmodules/llvm-toolset:latest
+      - image: silkeh/clang:12
     steps:
       - checkout
       - run: