From d7a037c26b3fadf1107c803f9fcc0ae8d21a0df7 Mon Sep 17 00:00:00 2001
From: Eldar Zaitov <kyprizel@gmail.com>
Date: Sat, 25 Apr 2020 10:12:38 +0300
Subject: [PATCH] split fuzzers and sanitizers

---
 CMakeLists.txt                       |  3 ++-
 cmake/fuzzer.cmake                   | 21 +++++++++++++++++++++
 cmake/sanitize.cmake                 | 12 ------------
 src/Compression/tests/CMakeLists.txt |  3 +--
 4 files changed, 24 insertions(+), 15 deletions(-)
 create mode 100644 cmake/fuzzer.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a05989fbb6a..feef2e1a678 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -84,9 +84,10 @@ option (ENABLE_FUZZING "Enables fuzzing instrumentation" OFF)
 if (ENABLE_FUZZING)
     message (STATUS "Fuzzing instrumentation enabled")
     set (WITH_COVERAGE ON)
-    set (SANITIZE "libfuzzer")
+    set (FUZZER "libfuzzer")
 endif()
 
+include (cmake/fuzzer.cmake)
 include (cmake/sanitize.cmake)
 
 if (CMAKE_GENERATOR STREQUAL "Ninja" AND NOT DISABLE_COLORED_BUILD)
diff --git a/cmake/fuzzer.cmake b/cmake/fuzzer.cmake
new file mode 100644
index 00000000000..7ce4559ffae
--- /dev/null
+++ b/cmake/fuzzer.cmake
@@ -0,0 +1,21 @@
+option (FUZZER "Enable fuzzer: libfuzzer")
+
+if (FUZZER)
+    if (FUZZER STREQUAL "libfuzzer")
+        # NOTE: Eldar Zaitov decided to name it "libfuzzer" instead of "fuzzer" to keep in mind another possible fuzzer backends.
+        # NOTE: no-link means that all the targets are built with instrumentation for fuzzer, but only some of them (tests) have entry point for fuzzer and it's not checked.
+        set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SAN_FLAGS} -fsanitize=fuzzer-no-link")
+        set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SAN_FLAGS} -fsanitize=fuzzer-no-link")
+        if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+            set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fsanitize=fuzzer-no-link")
+        endif()
+
+        # NOTE: oss-fuzz can change LIB_FUZZING_ENGINE variable
+        if (NOT LIB_FUZZING_ENGINE)
+            set (LIB_FUZZING_ENGINE "-fsanitize=fuzzer")
+        endif ()
+
+    else ()
+        message (FATAL_ERROR "Unknown fuzzer type: ${FUZZER}")
+    endif ()
+endif()
diff --git a/cmake/sanitize.cmake b/cmake/sanitize.cmake
index 7d906de7602..e9fa0a01d4a 100644
--- a/cmake/sanitize.cmake
+++ b/cmake/sanitize.cmake
@@ -58,18 +58,6 @@ if (SANITIZE)
         # llvm-tblgen, that is used during LLVM build, doesn't work with UBSan.
         set (ENABLE_EMBEDDED_COMPILER 0 CACHE BOOL "")
 
-    elseif (SANITIZE STREQUAL "libfuzzer")
-        # NOTE: Eldar Zaitov decided to name it "libfuzzer" instead of "fuzzer" to keep in mind another possible fuzzer backends.
-        # NOTE: no-link means that all the targets are built with instrumentation for fuzzer, but only some of them (tests) have entry point for fuzzer and it's not checked.
-        set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SAN_FLAGS} -fsanitize=fuzzer-no-link,address,undefined -fsanitize-address-use-after-scope")
-        set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SAN_FLAGS} -fsanitize=fuzzer-no-link,address,undefined -fsanitize-address-use-after-scope")
-        if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-            set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fsanitize=fuzzer-no-link,address,undefined -fsanitize-address-use-after-scope")
-        endif()
-        if (MAKE_STATIC_LIBRARIES AND CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-            set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static-libasan -static-libubsan")
-        endif ()
-        set (LIBFUZZER_CMAKE_CXX_FLAGS "-fsanitize=fuzzer,address,undefined -fsanitize-address-use-after-scope")
     else ()
         message (FATAL_ERROR "Unknown sanitizer type: ${SANITIZE}")
     endif ()
diff --git a/src/Compression/tests/CMakeLists.txt b/src/Compression/tests/CMakeLists.txt
index 6b13d4eb5cd..c7917382791 100644
--- a/src/Compression/tests/CMakeLists.txt
+++ b/src/Compression/tests/CMakeLists.txt
@@ -6,6 +6,5 @@ target_link_libraries (cached_compressed_read_buffer PRIVATE dbms)
 
 if (ENABLE_FUZZING)
     add_executable (compressed_buffer_fuzz compressed_buffer_fuzz.cpp)
-    target_link_libraries (compressed_buffer_fuzz PRIVATE dbms)
-    set_target_properties(compressed_buffer_fuzz PROPERTIES LINK_FLAGS ${LIBFUZZER_CMAKE_CXX_FLAGS})
+    target_link_libraries (compressed_buffer_fuzz PRIVATE dbms ${LIB_FUZZING_ENGINE})
 endif ()