From 0f24d396f362bc4709ff73c7cf7fb09910adb4ff Mon Sep 17 00:00:00 2001
From: Alex Shabalin <alex.shabalin@pm.me>
Date: Thu, 15 Feb 2024 12:35:08 +0100
Subject: [PATCH] Fuzzers do not require Catch2

---
 CMakeLists.txt              | 15 ++++++++-------
 extra/fuzzer/CMakeLists.txt |  3 +++
 flake.nix                   | 11 ++++++-----
 test/CMakeLists.txt         |  1 +
 4 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 091f2b99..386cc725 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -39,6 +39,7 @@ option(immer_BUILD_TESTS "Build tests" ON)
 option(immer_BUILD_EXAMPLES "Build examples" ON)
 option(immer_BUILD_DOCS "Build docs" ON)
 option(immer_BUILD_EXTRAS "Build extras" ON)
+option(immer_INSTALL_FUZZERS "Install fuzzers" off)
 
 set(CXX_STANDARD 14 CACHE STRING "c++ standard number")
 
@@ -136,16 +137,16 @@ endif()
 #  Testing
 #  =======
 
+if (immer_BUILD_TESTS OR immer_BUILD_EXAMPLES OR immer_BUILD_EXTRAS)
+  add_custom_target(check
+  COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure
+  WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+  COMMENT "Build and run all the tests and examples.")
+endif()
+
 if (immer_BUILD_TESTS)
   enable_testing()
 
-  find_package(Catch2 REQUIRED)
-
-  add_custom_target(check
-    COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-    COMMENT "Build and run all the tests and examples.")
-
   add_subdirectory(test)
   add_subdirectory(benchmark)
 endif()
diff --git a/extra/fuzzer/CMakeLists.txt b/extra/fuzzer/CMakeLists.txt
index 777289f8..2c160f79 100644
--- a/extra/fuzzer/CMakeLists.txt
+++ b/extra/fuzzer/CMakeLists.txt
@@ -26,4 +26,7 @@ foreach(_file IN LISTS immer_fuzzers)
   if (CHECK_FUZZERS)
     add_test("fuzzer/${_output}" ${_output} -max_total_time=1)
   endif()
+  if (immer_INSTALL_FUZZERS)
+    install(TARGETS ${_target} DESTINATION bin)
+  endif()
 endforeach()
diff --git a/flake.nix b/flake.nix
index 0f67ca16..18247fff 100644
--- a/flake.nix
+++ b/flake.nix
@@ -49,7 +49,7 @@
             };
           };
 
-          inherit (self.packages.${system}) unit-tests;
+          inherit (self.packages.${system}) unit-tests fuzzers-debug;
         }
         // pkgs.lib.optionalAttrs pkgs.stdenv.isLinux {
           unit-tests-valgrind = self.packages.${system}.unit-tests.overrideAttrs (prev: {
@@ -94,18 +94,19 @@
         default = self.packages.${system}.immer;
 
         fuzzers-debug = (withLLVM self.packages.${system}.immer).overrideAttrs (prev: {
-          buildInputs = with pkgs; [catch2_3 boehmgc boost fmt];
+          name = "immer-fuzzers";
+          # Fuzzers should be built with minimal dependencies to use them easily with OSS-Fuzz
+          buildInputs = with pkgs; [boehmgc];
           nativeBuildInputs = with pkgs; [cmake ninja];
           dontBuild = false;
           dontStrip = true;
           # fuzzers target is not built by default
           ninjaFlags = ["fuzzers"];
+          cmakeBuildType = "Debug";
           cmakeFlags = [
-            "-DCMAKE_BUILD_TYPE=Debug"
+            "-DENABLE_ASAN=ON"
             "-Dimmer_BUILD_TESTS=OFF"
-            "-Dimmer_BUILD_EXAMPLES=OFF"
             "-Dimmer_INSTALL_FUZZERS=ON"
-            "-DENABLE_ASAN=ON"
           ];
         });
 
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 590dc775..1812e9ed 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -6,6 +6,7 @@ add_custom_target(tests
   COMMENT "Build all the unit tests.")
 add_dependencies(check tests)
 
+find_package(Catch2 REQUIRED)
 include(CTest)
 
 file(GLOB_RECURSE immer_unit_tests "*.cpp")