[libFuzzer] Always build libFuzzer

There are two reasons why users might want to build libfuzzer:
- To fuzz LLVM itself
- To get the libFuzzer.a archive file, so that they can attach it to their code
This change always builds libfuzzer, and supports the second use case if the specified flag is set.

The point of this patch is to have something that can potentially be shipped with the compiler, and this also ensures that the version of libFuzzer is correct to use with that compiler.

Patch by George Karpenkov.

Differential Revision: https://reviews.llvm.org/D32096

llvm-svn: 301010

1 files changed, 20 insertions, 14 deletions

diff --git a/llvm/lib/Fuzzer/CMakeLists.txt b/llvm/lib/Fuzzer/CMakeLists.txt
index d44c12de3e1..c8d5d02771e 100644
--- a/llvm/lib/Fuzzer/CMakeLists.txt
+++ b/llvm/lib/Fuzzer/CMakeLists.txt
@@ -11,17 +11,14 @@ if( NOT HAS_THREAD_LOCAL )
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Dthread_local=__thread")
 endif()
 
-set(LIBFUZZER_FLAGS_BASE "${CMAKE_CXX_FLAGS}")
-# Disable the coverage and sanitizer instrumentation for the fuzzer itself.
-set(CMAKE_CXX_FLAGS "${LIBFUZZER_FLAGS_BASE} -fno-sanitize-coverage=trace-pc-guard,edge,trace-cmp,indirect-calls,8bit-counters -Werror")
 if( LLVM_USE_SANITIZE_COVERAGE )
-  if(NOT "${LLVM_USE_SANITIZER}" STREQUAL "Address")
-    message(FATAL_ERROR
-      "LibFuzzer and its tests require LLVM_USE_SANITIZER=Address and "
-      "LLVM_USE_SANITIZE_COVERAGE=YES to be set."
-      )
-  endif()
-  add_library(LLVMFuzzerNoMainObjects OBJECT
+  set(LIBFUZZER_FLAGS_BASE "${CMAKE_CXX_FLAGS}")
+
+  # Disable the coverage and sanitizer instrumentation for the fuzzer itself.
+  set(CMAKE_CXX_FLAGS "${LIBFUZZER_FLAGS_BASE} -fno-sanitize-coverage=trace-pc-guard,edge,trace-cmp,indirect-calls,8bit-counters -Werror")
+endif()
+
+add_library(LLVMFuzzerNoMainObjects OBJECT
     FuzzerCrossOver.cpp
     FuzzerDriver.cpp
     FuzzerExtFunctionsDlsym.cpp
@@ -45,15 +42,24 @@ if( LLVM_USE_SANITIZE_COVERAGE )
     FuzzerUtilPosix.cpp
     FuzzerUtilWindows.cpp
     )
-  add_library(LLVMFuzzerNoMain STATIC
+add_library(LLVMFuzzerNoMain STATIC
     $<TARGET_OBJECTS:LLVMFuzzerNoMainObjects>
     )
-  target_link_libraries(LLVMFuzzerNoMain ${LLVM_PTHREAD_LIB})
-  add_library(LLVMFuzzer STATIC
+target_link_libraries(LLVMFuzzerNoMain ${LLVM_PTHREAD_LIB})
+add_library(LLVMFuzzer STATIC
     FuzzerMain.cpp
     $<TARGET_OBJECTS:LLVMFuzzerNoMainObjects>
     )
-  target_link_libraries(LLVMFuzzer ${LLVM_PTHREAD_LIB})
+target_link_libraries(LLVMFuzzer ${LLVM_PTHREAD_LIB})
+
+if( LLVM_USE_SANITIZE_COVERAGE )
+
+  if(NOT "${LLVM_USE_SANITIZER}" STREQUAL "Address")
+    message(FATAL_ERROR
+      "LibFuzzer tests require LLVM_USE_SANITIZER=Address and "
+      "LLVM_USE_SANITIZE_COVERAGE=YES to be set."
+      )
+  endif()
 
   if( LLVM_INCLUDE_TESTS )
     add_subdirectory(test)