[fuzzer] Use RawPrint instead of Printf for instrumentation warning

Summary:
Use RawPrint instead of Printf for instrumentation warning because
Printf doesn't work on Win when instrumentation is being
initialized (since OutputFile is not yet initialized).

Reviewers: kcc

Reviewed By: kcc

Differential Revision: https://reviews.llvm.org/D57531

llvm-svn: 352789

Author: jonathanmetzman

compiler-rt/lib/fuzzer/FuzzerIOWindows.cpp

@@ -334,7 +334,7 @@ bool IsInterestingCoverageFile(const std::string &FileName) {
 
 void RawPrint(const char *Str) {
   // Not tested, may or may not work. Fix if needed.
-  Printf("%s", Str);
+  write(2, Str, strlen(Str));
 }
 
 }  // namespace fuzzer

compiler-rt/lib/fuzzer/FuzzerTracePC.cpp

@@ -403,9 +403,13 @@ uintptr_t TracePC::GetMaxStackOffset() const {
 }
 
 void WarnAboutDeprecatedInstrumentation(const char *flag) {
-  Printf("libFuzzer does not support %s any more.\n"
-         "Please either migrate to a compiler that supports -fsanitize=fuzzer\n"
-         "or use an older version of libFuzzer\n", flag);
+  // Use RawPrint because Printf cannot be used on Windows before OutputFile is
+  // initialized.
+  RawPrint(flag);
+  RawPrint(
+      " is no longer supported by libFuzzer.\n"
+      "Please either migrate to a compiler that supports -fsanitize=fuzzer\n"
+      "or use an older version of libFuzzer\n");
   exit(1);
 }
 
@@ -415,16 +419,16 @@ extern "C" {
 ATTRIBUTE_INTERFACE
 ATTRIBUTE_NO_SANITIZE_ALL
 void __sanitizer_cov_trace_pc_guard(uint32_t *Guard) {
-  fuzzer::WarnAboutDeprecatedInstrumentation("-fsanitize-coverage=trace-pc");
+  fuzzer::WarnAboutDeprecatedInstrumentation(
+      "-fsanitize-coverage=trace-pc-guard");
 }
 
 // Best-effort support for -fsanitize-coverage=trace-pc, which is available
 // in both Clang and GCC.
 ATTRIBUTE_INTERFACE
 ATTRIBUTE_NO_SANITIZE_ALL
 void __sanitizer_cov_trace_pc() {
-  fuzzer::WarnAboutDeprecatedInstrumentation(
-      "-fsanitize-coverage=trace-pc-guard");
+  fuzzer::WarnAboutDeprecatedInstrumentation("-fsanitize-coverage=trace-pc");
 }
 
 ATTRIBUTE_INTERFACE

compiler-rt/test/fuzzer/deprecated-instrumentation.test

@@ -1,4 +1,4 @@
-CHECK: libFuzzer does not support -fsanitize-coverage=trace-pc
+CHECK: -fsanitize-coverage=trace-pc is no longer supported by libFuzzer
 RUN: %cpp_compiler %S/SimpleTest.cpp -c -o %t-SimpleTest.o -fsanitize-coverage=trace-pc
 RUN: %cpp_compiler %t-SimpleTest.o -o %t-SimpleTest
 RUN: not %run %t-SimpleTest 2>&1 | FileCheck %s