diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -1088,6 +1088,23 @@
       Sanitizers.has(SanitizerKind::Address))
     CmdArgs.push_back("-fno-assume-sane-operator-new");
 
+  // libFuzzer wants to intercept calls to certain library functions, so the
+  // following -fno-builtin-* flags force the compiler to emit interposable
+  // libcalls to these functions. Other sanitizers effectively do the same thing
+  // by marking all library call sites with NoBuiltin attribute in their LLVM
+  // pass. (see llvm::maybeMarkSanitizerLibraryCallNoBuiltin)
+  if (Sanitizers.has(SanitizerKind::FuzzerNoLink)) {
+    CmdArgs.push_back("-fno-builtin-bcmp");
+    CmdArgs.push_back("-fno-builtin-memcmp");
+    CmdArgs.push_back("-fno-builtin-strncmp");
+    CmdArgs.push_back("-fno-builtin-strcmp");
+    CmdArgs.push_back("-fno-builtin-strncasecmp");
+    CmdArgs.push_back("-fno-builtin-strcasecmp");
+    CmdArgs.push_back("-fno-builtin-strstr");
+    CmdArgs.push_back("-fno-builtin-strcasestr");
+    CmdArgs.push_back("-fno-builtin-memmem");
+  }
+
   // Require -fvisibility= flag on non-Windows when compiling if vptr CFI is
   // enabled.
   if (Sanitizers.hasOneOf(CFIClasses) && !TC.getTriple().isOSWindows() &&
diff --git a/compiler-rt/test/fuzzer/noasan-bcmp.test b/compiler-rt/test/fuzzer/noasan-bcmp.test
new file mode 100644
--- /dev/null
+++ b/compiler-rt/test/fuzzer/noasan-bcmp.test
@@ -0,0 +1,4 @@
+UNSUPPORTED: darwin, freebsd, windows
+RUN: %cpp_compiler -fno-sanitize=address -DMEMCMP=bcmp %S/MemcmpTest.cpp -o %t
+RUN: not %run %t -seed=1 -runs=10000000 2>&1 | FileCheck %s
+CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-memcmp.test b/compiler-rt/test/fuzzer/noasan-memcmp.test
--- a/compiler-rt/test/fuzzer/noasan-memcmp.test
+++ b/compiler-rt/test/fuzzer/noasan-memcmp.test
@@ -1,9 +1,9 @@
 UNSUPPORTED: darwin, freebsd, windows
 
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-memcmp %S/MemcmpTest.cpp -o %t-NoAsanMemcmpTest
+RUN: %cpp_compiler -fno-sanitize=address %S/MemcmpTest.cpp -o %t-NoAsanMemcmpTest
 RUN: not %run %t-NoAsanMemcmpTest -seed=1 -runs=10000000   2>&1 | FileCheck %s
 
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc -fno-builtin-memcmp %S/CustomAllocator.cpp %S/MemcmpTest.cpp -o %t-NoAsanCustomAllocatorMemcmpTest
+RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc %S/CustomAllocator.cpp %S/MemcmpTest.cpp -o %t-NoAsanCustomAllocatorMemcmpTest
 RUN: not %run %t-NoAsanCustomAllocatorMemcmpTest -seed=1 -runs=10000000   2>&1 | FileCheck %s
 
 CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-memcmp64.test b/compiler-rt/test/fuzzer/noasan-memcmp64.test
--- a/compiler-rt/test/fuzzer/noasan-memcmp64.test
+++ b/compiler-rt/test/fuzzer/noasan-memcmp64.test
@@ -1,6 +1,6 @@
 UNSUPPORTED: darwin, freebsd, windows
 
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-memcmp %S/Memcmp64BytesTest.cpp -o %t-NoAsanMemcmp64BytesTest
+RUN: %cpp_compiler -fno-sanitize=address %S/Memcmp64BytesTest.cpp -o %t-NoAsanMemcmp64BytesTest
 RUN: not %run %t-NoAsanMemcmp64BytesTest -seed=1 -runs=1000000   2>&1 | FileCheck %s
 
 CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-strcmp.test b/compiler-rt/test/fuzzer/noasan-strcmp.test
--- a/compiler-rt/test/fuzzer/noasan-strcmp.test
+++ b/compiler-rt/test/fuzzer/noasan-strcmp.test
@@ -1,9 +1,9 @@
 UNSUPPORTED: darwin, freebsd, windows
 
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-strcmp %S/StrcmpTest.cpp -o %t-NoAsanStrcmpTest
+RUN: %cpp_compiler -fno-sanitize=address %S/StrcmpTest.cpp -o %t-NoAsanStrcmpTest
 RUN: not %run %t-NoAsanStrcmpTest -seed=1 -runs=2000000   2>&1 | FileCheck %s
 
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc -fno-builtin-strcmp %S/CustomAllocator.cpp %S/StrcmpTest.cpp -o %t-NoAsanCustomAllocatorStrcmpTest
+RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc %S/CustomAllocator.cpp %S/StrcmpTest.cpp -o %t-NoAsanCustomAllocatorStrcmpTest
 RUN: not %run %t-NoAsanCustomAllocatorStrcmpTest -seed=1 -runs=2000000   2>&1 | FileCheck %s
 
 CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-strncmp.test b/compiler-rt/test/fuzzer/noasan-strncmp.test
--- a/compiler-rt/test/fuzzer/noasan-strncmp.test
+++ b/compiler-rt/test/fuzzer/noasan-strncmp.test
@@ -1,9 +1,9 @@
 UNSUPPORTED: darwin, freebsd, windows
 
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-strncmp %S/StrncmpTest.cpp -o %t-NoAsanStrncmpTest
+RUN: %cpp_compiler -fno-sanitize=address %S/StrncmpTest.cpp -o %t-NoAsanStrncmpTest
 RUN: not %run %t-NoAsanStrncmpTest -seed=2 -runs=10000000   2>&1 | FileCheck %s
 
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc -fno-builtin-strncmp %S/CustomAllocator.cpp %S/StrncmpTest.cpp -o %t-NoAsanCustomAllocatorStrncmpTest
+RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc %S/CustomAllocator.cpp %S/StrncmpTest.cpp -o %t-NoAsanCustomAllocatorStrncmpTest
 RUN: not %run %t-NoAsanCustomAllocatorStrncmpTest -seed=2 -runs=10000000   2>&1 | FileCheck %s
 
 CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-strstr.test b/compiler-rt/test/fuzzer/noasan-strstr.test
--- a/compiler-rt/test/fuzzer/noasan-strstr.test
+++ b/compiler-rt/test/fuzzer/noasan-strstr.test
@@ -1,9 +1,9 @@
 UNSUPPORTED: darwin, freebsd, windows
 
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-strstr %S/StrstrTest.cpp -o %t-NoAsanStrstrTest
+RUN: %cpp_compiler -fno-sanitize=address %S/StrstrTest.cpp -o %t-NoAsanStrstrTest
 RUN: not %run %t-NoAsanStrstrTest -seed=1 -runs=2000000   2>&1 | FileCheck %s
 
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc -fno-builtin-strstr %S/CustomAllocator.cpp %S/StrstrTest.cpp -o %t-NoAsanCustomAllocatorStrstrTest
+RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc %S/CustomAllocator.cpp %S/StrstrTest.cpp -o %t-NoAsanCustomAllocatorStrstrTest
 RUN: not %run %t-NoAsanCustomAllocatorStrstrTest -seed=1 -runs=2000000   2>&1 | FileCheck %s
 
 CHECK: BINGO