[Sanitizer] Add internal_isatty to sanitizer_libc and PrintsToTty to determine whether error reports are printed to terminal

llvm-svn: 167298

compiler-rt/lib/sanitizer_common/sanitizer_common.cc

@@ -48,18 +48,27 @@ void NORETURN CheckFailed(const char *file, int line, const char *cond,
   Die();
 }
 
+static void MaybeOpenReportFile() {
+  if (report_fd != kInvalidFd)
+    return;
+  fd_t fd = internal_open(report_path, true);
+  if (fd == kInvalidFd) {
+    report_fd = kStderrFd;
+    Report("ERROR: Can't open file: %s\n", report_path);
+    Die();
+  }
+  report_fd = fd;
+}
+
+bool PrintsToTty() {
+  MaybeOpenReportFile();
+  return internal_isatty(report_fd);
+}
+
 void RawWrite(const char *buffer) {
   static const char *kRawWriteError = "RawWrite can't output requested buffer!";
   uptr length = (uptr)internal_strlen(buffer);
-  if (report_fd == kInvalidFd) {
-    fd_t fd = internal_open(report_path, true);
-    if (fd == kInvalidFd) {
-      report_fd = kStderrFd;
-      Report("ERROR: Can't open file: %s\n", report_path);
-      Die();
-    }
-    report_fd = fd;
-  }
+  MaybeOpenReportFile();
   if (length != internal_write(report_fd, buffer, length)) {
     internal_write(report_fd, kRawWriteError, internal_strlen(kRawWriteError));
     Die();

compiler-rt/lib/sanitizer_common/sanitizer_common.h

@@ -98,6 +98,7 @@ void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback);
 
 // IO
 void RawWrite(const char *buffer);
+bool PrintsToTty();
 void Printf(const char *format, ...);
 void Report(const char *format, ...);
 void SetPrintfAndReportCallback(void (*callback)(const char *));

compiler-rt/lib/sanitizer_common/sanitizer_libc.h

@@ -59,6 +59,7 @@ const fd_t kStdinFd = 0;
 const fd_t kStdoutFd = 1;
 const fd_t kStderrFd = 2;
 int internal_close(fd_t fd);
+int internal_isatty(fd_t fd);
 fd_t internal_open(const char *filename, bool write);
 uptr internal_read(fd_t fd, void *buf, uptr count);
 uptr internal_write(fd_t fd, const void *buf, uptr count);

compiler-rt/lib/sanitizer_common/sanitizer_posix.cc

@@ -184,6 +184,10 @@ int Atexit(void (*function)(void)) {
 #endif
 }
 
+int internal_isatty(fd_t fd) {
+  return isatty(fd);
+}
+
 }  // namespace __sanitizer
 
 #endif  // __linux__ || __APPLE_

compiler-rt/lib/sanitizer_common/sanitizer_win.cc

@@ -154,6 +154,10 @@ int internal_close(fd_t fd) {
   UNIMPLEMENTED();
 }
 
+int internal_isatty(fd_t fd) {
+  UNIMPLEMENTED();
+}
+
 fd_t internal_open(const char *filename, bool write) {
   UNIMPLEMENTED();
 }