[libFuzzer] Use custom target instead of list of binaries for tests.

[mpividori]

Summary

I update the cmake code to use a custom target TestBinaries instead of a list of targets.
This simplifies cmake, and fix some errors. This way, we don't have to propagate the values into parents directories. We only need to use add_dependencies.

[kcc]

LGTM,
but please manually verify that the tests still work (remove the test binaries, then run check-fuzzer)

lib/Fuzzer/test/CMakeLists.txt

if(MSVC)
   # on the implementation of the compiler-rt, the simplest option is to change
   # the rules for linking executables and shared libraries, using the compiler
   # instead of link.exe. Clang will consider the sanitizer flags, and
   # automatically provide the required libraries to the linker.
   set(CMAKE_CXX_LINK_EXECUTABLE "<CMAKE_CXX_COMPILER> <FLAGS> ${CMAKE_CXX_FLAGS} ${CRT_FLAG} <OBJECTS> -o <TARGET> <LINK_LIBRARIES> /link <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS>")
   set(CMAKE_CXX_CREATE_SHARED_LIBRARY "<CMAKE_CXX_COMPILER> ${CMAKE_CXX_FLAGS} ${CRT_FLAG} /LD <CMAKE_SHARED_LIBRARY_CXX_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS> <CMAKE_SHARED_LIBRARY_SONAME_CXX_FLAG> <TARGET_SONAME> -o <TARGET> <OBJECTS> <LINK_LIBRARIES> /link <LINK_FLAGS>")
 endif()
 
+add_custom_target(TestBinaries)
+
 # add_libfuzzer_test(<name>
 #   SOURCES source0.cpp [source1.cpp ...]
 #   )
 #
 #   Declares a LibFuzzer test executable with target name LLVMFuzzer-<name>.
 #
 #   One or more source files to be compiled into the binary must be declared
 #   after the SOURCES keyword.
 function(add_libfuzzer_test name)
   set(multi_arg_options "SOURCES")
   cmake_parse_arguments(
     "add_libfuzzer_test" "" "" "${multi_arg_options}" ${ARGN})
   if ("${add_libfuzzer_test_SOURCES}" STREQUAL "")
     message(FATAL_ERROR "Source files must be specified")
   endif()
   add_executable(LLVMFuzzer-${name}
     ${add_libfuzzer_test_SOURCES}
     )
   target_link_libraries(LLVMFuzzer-${name} LLVMFuzzer)
   # Place binary where llvm-lit expects to find it
   set_target_properties(LLVMFuzzer-${name}
     PROPERTIES RUNTIME_OUTPUT_DIRECTORY
     "${CMAKE_BINARY_DIR}/lib/Fuzzer/test"
     )
-  set(TestBinaries ${TestBinaries} LLVMFuzzer-${name} PARENT_SCOPE)
+  add_dependencies(TestBinaries LLVMFuzzer-${name})
 endfunction()
 
-# Variable to keep track of all test targets
-set(TestBinaries)
-
 ###############################################################################
 # Basic tests
 ###############################################################################
 
 set(Tests
   AbsNegAndConstantTest
   AbsNegAndConstant64Test
   AccumulateAllocationsTest
target_link_libraries(LLVMFuzzer-Unittest
   gtest_main
   LLVMFuzzerNoMain
   )
 
 target_include_directories(LLVMFuzzer-Unittest PRIVATE
   "${LLVM_MAIN_SRC_DIR}/utils/unittest/googletest/include"
   )
 
-set(TestBinaries ${TestBinaries} LLVMFuzzer-Unittest)
+add_dependencies(TestBinaries LLVMFuzzer-Unittest)
 set_target_properties(LLVMFuzzer-Unittest
   PROPERTIES RUNTIME_OUTPUT_DIRECTORY
   "${CMAKE_CURRENT_BINARY_DIR}"
 )
 
-set(TestBinaries ${TestBinaries} LLVMFuzzer-StandaloneInitializeTest)
+add_dependencies(TestBinaries LLVMFuzzer-StandaloneInitializeTest)
 set_target_properties(LLVMFuzzer-StandaloneInitializeTest
   PROPERTIES RUNTIME_OUTPUT_DIRECTORY
   "${CMAKE_CURRENT_BINARY_DIR}"
 )
 
 ###############################################################################
 # Additional tests
 ###############################################################################
set_output_directory(LLVMFuzzer-DSO2
     LIBRARY_DIR "${CMAKE_BINARY_DIR}/lib/Fuzzer/test")
 else(MSVC)
   set_output_directory(LLVMFuzzer-DSO1
     LIBRARY_DIR "${CMAKE_BINARY_DIR}/lib/Fuzzer/lib")
   set_output_directory(LLVMFuzzer-DSO2
     LIBRARY_DIR "${CMAKE_BINARY_DIR}/lib/Fuzzer/lib")
 endif()
 
-set(TestBinaries ${TestBinaries} LLVMFuzzer-DSOTest)
+add_dependencies(TestBinaries LLVMFuzzer-DSOTest)
 
 ###############################################################################
 # Configure lit to run the tests
 #
 # Note this is done after declaring all tests so we can inform lit if any tests
 # need to be disabled.
 ###############################################################################
 set(LIBFUZZER_POSIX 1)
 if (MSVC)
   set(LIBFUZZER_POSIX 0)
 endif()
 
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
   )
 
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/unit/lit.site.cfg.in
   ${CMAKE_CURRENT_BINARY_DIR}/unit/lit.site.cfg
   )
 
 add_lit_testsuite(check-fuzzer "Running Fuzzer tests"
     ${CMAKE_CURRENT_BINARY_DIR}
-    DEPENDS ${TestBinaries}
+    DEPENDS TestBinaries
     )
 
 # Don't add dependencies on Windows. The linker step would fail on Windows,
 # since cmake will use link.exe for linking and won't include compiler-rt libs.
 if(NOT MSVC)
   add_dependencies(check-fuzzer FileCheck sancov not)
 endif()

lib/Fuzzer/test/no-coverage/CMakeLists.txt

if(NOT MSVC)
   add_executable(AFLDriverTest
     ../AFLDriverTest.cpp ../../afl/afl_driver.cpp)
 
   set_target_properties(AFLDriverTest
       PROPERTIES RUNTIME_OUTPUT_DIRECTORY
       "${CMAKE_BINARY_DIR}/lib/Fuzzer/test"
       )
 
-  # Propagate value into parent directory
-  set(TestBinaries ${TestBinaries} AFLDriverTest PARENT_SCOPE)
+  add_dependencies(TestBinaries AFLDriverTest)
 endif()

lib/Fuzzer/test/ubsan/CMakeLists.txt

 # These tests are instrumented with ubsan in non-recovery mode.
 
 set(CMAKE_CXX_FLAGS
   "${LIBFUZZER_FLAGS_BASE} -fsanitize=undefined -fno-sanitize-recover=all")
 
 set(UbsanTests
   SignedIntOverflowTest
   )
 
 foreach(Test ${UbsanTests})
   add_libfuzzer_test(${Test}-Ubsan SOURCES ../${Test}.cpp)
 endforeach()
-
-# Propagate value into parent directory
-set(TestBinaries ${TestBinaries} PARENT_SCOPE)

lib/Fuzzer/test/uninstrumented/CMakeLists.txt

 # These tests are not instrumented with coverage and don't
 # have coverage rt in the binary.
 
 set(CMAKE_CXX_FLAGS
   "${LIBFUZZER_FLAGS_BASE} -fno-sanitize=all -fno-sanitize-coverage=edge,trace-cmp,indirect-calls,8bit-counters,trace-pc-guard")
 
 set(UninstrumentedTests
   UninstrumentedTest
   )
 
 foreach(Test ${UninstrumentedTests})
   add_libfuzzer_test(${Test}-Uninstrumented SOURCES ../${Test}.cpp)
 endforeach()
-
-# Propagate value into parent directory
-set(TestBinaries ${TestBinaries} PARENT_SCOPE)