Add -fsanitize=fuzzer-no-link flag to the driver.

The flag will perform instrumentation necessary to the fuzzing,
but will NOT link libLLVMFuzzer.a library.
Necessary when modifying CFLAGS for projects which may produce
executables as well as a fuzzable target.

Differential Revision: https://reviews.llvm.org/D36600

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@310733 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/Sanitizers.def b/include/clang/Basic/Sanitizers.def
index 28a92abf00b743973893b8ea9d29070c40be094b..d6df6171729a8339389d2923904856a124eabcfe 100644 (file)
--- a/include/clang/Basic/Sanitizers.def
+++ b/include/clang/Basic/Sanitizers.def
@@ -50,6 +50,9 @@ SANITIZER("memory", Memory)
 // libFuzzer
 SANITIZER("fuzzer", Fuzzer)
 
+// libFuzzer-required instrumentation, no linking.
+SANITIZER("fuzzer-no-link", FuzzerNoLink)
+
 // ThreadSanitizer
 SANITIZER("thread", Thread)
 

diff --git a/lib/Driver/SanitizerArgs.cpp b/lib/Driver/SanitizerArgs.cpp
index 2f12c6d4a5f22533d9a9b2b8d6b64192c785d7d6..e411629ca425e0fec51255d8f0b97fb2bb04d440 100644 (file)
--- a/lib/Driver/SanitizerArgs.cpp
+++ b/lib/Driver/SanitizerArgs.cpp
@@ -32,7 +32,7 @@ enum : SanitizerMask {
   RequiresPIE = DataFlow,
   NeedsUnwindTables = Address | Thread | Memory | DataFlow,
   SupportsCoverage = Address | KernelAddress | Memory | Leak | Undefined |
-                     Integer | Nullability | DataFlow | Fuzzer,
+                     Integer | Nullability | DataFlow | Fuzzer | FuzzerNoLink,
   RecoverableByDefault = Undefined | Integer | Nullability,
   Unrecoverable = Unreachable | Return,
   LegacyFsanitizeRecoverMask = Undefined | Integer,
@@ -286,8 +286,11 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
       Add &= ~InvalidTrappingKinds;
       Add &= Supported;
 
-      // Enable coverage if the fuzzing flag is set.
       if (Add & Fuzzer)
+        Add |= FuzzerNoLink;
+
+      // Enable coverage if the fuzzing flag is set.
+      if (Add & FuzzerNoLink)
         CoverageFeatures |= CoverageTracePCGuard | CoverageIndirCall |
                             CoverageTraceCmp | CoveragePCTable;
 

diff --git a/lib/Driver/ToolChains/Darwin.cpp b/lib/Driver/ToolChains/Darwin.cpp
index 7f55d3ed7f3d6f903fad9df14df8a8390d7023d3..f67e36ef635e40404ca6f570a9e94693b8c0c510 100644 (file)
--- a/lib/Driver/ToolChains/Darwin.cpp
+++ b/lib/Driver/ToolChains/Darwin.cpp
@@ -2018,6 +2018,7 @@ SanitizerMask Darwin::getSupportedSanitizers() const {
   Res |= SanitizerKind::Address;
   Res |= SanitizerKind::Leak;
   Res |= SanitizerKind::Fuzzer;
+  Res |= SanitizerKind::FuzzerNoLink;
   if (isTargetMacOS()) {
     if (!isMacosxVersionLT(10, 9))
       Res |= SanitizerKind::Vptr;

diff --git a/lib/Driver/ToolChains/Linux.cpp b/lib/Driver/ToolChains/Linux.cpp
index 08a27fa7fed10df9bde0d908badf4693ddcaae41..1adf9f7070d170102c4aac664f209d5354b2deeb 100644 (file)
--- a/lib/Driver/ToolChains/Linux.cpp
+++ b/lib/Driver/ToolChains/Linux.cpp
@@ -828,6 +828,7 @@ SanitizerMask Linux::getSupportedSanitizers() const {
   SanitizerMask Res = ToolChain::getSupportedSanitizers();
   Res |= SanitizerKind::Address;
   Res |= SanitizerKind::Fuzzer;
+  Res |= SanitizerKind::FuzzerNoLink;
   Res |= SanitizerKind::KernelAddress;
   Res |= SanitizerKind::Vptr;
   Res |= SanitizerKind::SafeStack;

diff --git a/test/Driver/fuzzer.c b/test/Driver/fuzzer.c
index 62ee06435c2fcd16750585ca1909ea5f69f885ee..c0fc4b6f661f934e5f9e2ec1e6f7e75593421333 100644 (file)
--- a/test/Driver/fuzzer.c
+++ b/test/Driver/fuzzer.c
@@ -21,6 +21,11 @@
 // RUN: %clang -fsanitize=fuzzer %s -shared -o %t.so -### 2>&1 | FileCheck --check-prefixes=CHECK-NOLIB-SO %s
 // CHECK-NOLIB-SO-NOT: libLLVMFuzzer.a
 
+// Check that we don't link in libFuzzer when compiling with -fsanitize=fuzzer-no-link.
+// RUN: %clang -fsanitize=fuzzer-no-link %s -target x86_64-apple-darwin14 -### 2>&1 | FileCheck --check-prefixes=CHECK-NOLIB,CHECK-COV %s
+// CHECK-NOLIB-NOT: libLLVMFuzzer.a
+// CHECK-COV: -fsanitize-coverage-trace-pc-guard
+
 // RUN: %clang -fsanitize=fuzzer -fsanitize-coverage=trace-pc %s -### 2>&1 | FileCheck --check-prefixes=CHECK-MSG %s
 // CHECK-MSG-NOT: argument unused during compilation