[Fuzzer] Use Zircon's public API on Fuchsia

[phosek]

Summary

The original libFuzzer Fuchsia port relied on convenience libraries,
but these are not exported as part of Fuchsia sysroot. This change
eliminates the use of these libraries and relies on public API only.

[jakehehrlich]

LGTM

compiler-rt/trunk/lib/fuzzer/FuzzerUtilFuchsia.cpp

 
 #if LIBFUZZER_FUCHSIA
 
 #include "FuzzerInternal.h"
 #include "FuzzerUtil.h"
 #include <cerrno>
 #include <cinttypes>
 #include <cstdint>
-#include <fbl/unique_fd.h>
 #include <fcntl.h>
 #include <launchpad/launchpad.h>
 #include <string>
 #include <thread>
+#include <unistd.h>
 #include <zircon/errors.h>
+#include <zircon/process.h>
 #include <zircon/status.h>
 #include <zircon/syscalls.h>
 #include <zircon/syscalls/port.h>
 #include <zircon/types.h>
-#include <zx/object.h>
-#include <zx/port.h>
-#include <zx/process.h>
-#include <zx/time.h>
 
 namespace fuzzer {
 
 namespace {
 
 // A magic value for the Zircon exception port, chosen to spell 'FUZZING'
 // when interpreted as a byte sequence on little-endian platforms.
 const uint64_t kFuzzingCrash = 0x474e495a5a5546;
 
 void AlarmHandler(int Seconds) {
   while (true) {
     SleepSeconds(Seconds);
     Fuzzer::StaticAlarmCallback();
   }
 }
 
 void InterruptHandler() {
   // Ctrl-C sends ETX in Zircon.
   while (getchar() != 0x03);
   Fuzzer::StaticInterruptCallback();
 }
 
-void CrashHandler(zx::port *Port) {
-  std::unique_ptr<zx::port> ExceptionPort(Port);
+void CrashHandler(zx_handle_t *Port) {
+  std::unique_ptr<zx_handle_t> ExceptionPort(Port);
   zx_port_packet_t Packet;
-  ExceptionPort->wait(zx::time::infinite(), &Packet, 0);
+  _zx_port_wait(*ExceptionPort, ZX_TIME_INFINITE, &Packet, 1);
   // Unbind as soon as possible so we don't receive exceptions from this thread.
-  if (zx_task_bind_exception_port(ZX_HANDLE_INVALID, ZX_HANDLE_INVALID,
+  if (_zx_task_bind_exception_port(ZX_HANDLE_INVALID, ZX_HANDLE_INVALID,
                                    kFuzzingCrash, 0) != ZX_OK) {
     // Shouldn't happen; if it does the safest option is to just exit.
     Printf("libFuzzer: unable to unbind exception port; aborting!\n");
     exit(1);
   }
   if (Packet.key != kFuzzingCrash) {
     Printf("libFuzzer: invalid crash key: %" PRIx64 "; aborting!\n",
            Packet.key);
     exit(1);
void SetSignalHandler(const FuzzingOptions &Options) {
   }
 
   // Early exit if no crash handler needed.
   if (!Options.HandleSegv && !Options.HandleBus && !Options.HandleIll &&
       !Options.HandleFpe && !Options.HandleAbrt)
     return;
 
   // Create an exception port
-  zx::port *ExceptionPort = new zx::port();
-  if ((rc = zx::port::create(0, ExceptionPort)) != ZX_OK) {
-    Printf("libFuzzer: zx_port_create failed: %s\n", zx_status_get_string(rc));
+  zx_handle_t *ExceptionPort = new zx_handle_t;
+  if ((rc = _zx_port_create(0, ExceptionPort)) != ZX_OK) {
+    Printf("libFuzzer: zx_port_create failed: %s\n", _zx_status_get_string(rc));
     exit(1);
   }
 
   // Bind the port to receive exceptions from our process
-  if ((rc = zx_task_bind_exception_port(zx_process_self(), ExceptionPort->get(),
+  if ((rc = _zx_task_bind_exception_port(_zx_process_self(), *ExceptionPort,
                                          kFuzzingCrash, 0)) != ZX_OK) {
     Printf("libFuzzer: unable to bind exception port: %s\n",
            zx_status_get_string(rc));
     exit(1);
   }
 
   // Set up the crash handler.
   std::thread T(CrashHandler, ExceptionPort);
   T.detach();
 }
 
 void SleepSeconds(int Seconds) {
-  zx::nanosleep(zx::deadline_after(zx::sec(Seconds)));
+  _zx_nanosleep(_zx_deadline_after(ZX_SEC(Seconds)));
 }
 
 unsigned long GetPid() {
   zx_status_t rc;
   zx_info_handle_basic_t Info;
-  if ((rc = zx_object_get_info(zx_process_self(), ZX_INFO_HANDLE_BASIC, &Info,
+  if ((rc = zx_object_get_info(_zx_process_self(), ZX_INFO_HANDLE_BASIC, &Info,
                                sizeof(Info), NULL, NULL)) != ZX_OK) {
     Printf("libFuzzer: unable to get info about self: %s\n",
            zx_status_get_string(rc));
     exit(1);
   }
   return Info.koid;
 }
 
 size_t GetPeakRSSMb() {
   zx_status_t rc;
   zx_info_task_stats_t Info;
-  if ((rc = zx_object_get_info(zx_process_self(), ZX_INFO_TASK_STATS, &Info,
+  if ((rc = _zx_object_get_info(_zx_process_self(), ZX_INFO_TASK_STATS, &Info,
                                sizeof(Info), NULL, NULL)) != ZX_OK) {
     Printf("libFuzzer: unable to get info about self: %s\n",
-           zx_status_get_string(rc));
+           _zx_status_get_string(rc));
     exit(1);
   }
   return (Info.mem_private_bytes + Info.mem_shared_bytes) >> 20;
 }
 
+template <typename Fn>
+class RunOnDestruction {
+ public:
+  explicit RunOnDestruction(Fn fn) : fn_(fn) {}
+  ~RunOnDestruction() { fn_(); }
+
+ private:
+  Fn fn_;
+};
+
+template <typename Fn>
+RunOnDestruction<Fn> at_scope_exit(Fn fn) {
+  return RunOnDestruction<Fn>(fn);
+}
+
 int ExecuteCommand(const Command &Cmd) {
   zx_status_t rc;
 
   // Convert arguments to C array
   auto Args = Cmd.getArguments();
   size_t Argc = Args.size();
   assert(Argc != 0);
   std::unique_ptr<const char *[]> Argv(new const char *[Argc]);
   for (size_t i = 0; i < Argc; ++i)
     Argv[i] = Args[i].c_str();
 
   // Create the basic launchpad.  Clone everything except stdio.
   launchpad_t *lp;
   launchpad_create(ZX_HANDLE_INVALID, Argv[0], &lp);
   launchpad_load_from_file(lp, Argv[0]);
   launchpad_set_args(lp, Argc, Argv.get());
   launchpad_clone(lp, LP_CLONE_ALL & (~LP_CLONE_FDIO_STDIO));
 
   // Determine stdout
   int FdOut = STDOUT_FILENO;
-  fbl::unique_fd OutputFile;
+
   if (Cmd.hasOutputFile()) {
     auto Filename = Cmd.getOutputFile();
-    OutputFile.reset(open(Filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0));
-    if (!OutputFile) {
+    FdOut = open(Filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0);
+    if (FdOut == -1) {
       Printf("libFuzzer: failed to open %s: %s\n", Filename.c_str(),
              strerror(errno));
       return ZX_ERR_IO;
     }
-    FdOut = OutputFile.get();
   }
+  auto CloseFdOut = at_scope_exit([&]() { close(FdOut); } );
 
   // Determine stderr
   int FdErr = STDERR_FILENO;
   if (Cmd.isOutAndErrCombined())
     FdErr = FdOut;
 
   // Clone the file descriptors into the new process
   if ((rc = launchpad_clone_fd(lp, STDIN_FILENO, STDIN_FILENO)) != ZX_OK ||
       (rc = launchpad_clone_fd(lp, FdOut, STDOUT_FILENO)) != ZX_OK ||
       (rc = launchpad_clone_fd(lp, FdErr, STDERR_FILENO)) != ZX_OK) {
-    Printf("libFuzzer: failed to clone FDIO: %s\n", zx_status_get_string(rc));
+    Printf("libFuzzer: failed to clone FDIO: %s\n", _zx_status_get_string(rc));
     return rc;
   }
 
   // Start the process
   zx_handle_t ProcessHandle = ZX_HANDLE_INVALID;
   const char *ErrorMsg = nullptr;
   if ((rc = launchpad_go(lp, &ProcessHandle, &ErrorMsg)) != ZX_OK) {
     Printf("libFuzzer: failed to launch '%s': %s, %s\n", Argv[0], ErrorMsg,
-           zx_status_get_string(rc));
+           _zx_status_get_string(rc));
     return rc;
   }
-  zx::process Process(ProcessHandle);
+  auto CloseHandle = at_scope_exit([&]() { _zx_handle_close(ProcessHandle); });
 
   // Now join the process and return the exit status.
-  if ((rc = Process.wait_one(ZX_PROCESS_TERMINATED, zx::time::infinite(),
-                             nullptr)) != ZX_OK) {
+  if ((rc = _zx_object_wait_one(ProcessHandle, ZX_PROCESS_TERMINATED,
+                                ZX_TIME_INFINITE, nullptr)) != ZX_OK) {
     Printf("libFuzzer: failed to join '%s': %s\n", Argv[0],
-           zx_status_get_string(rc));
+           _zx_status_get_string(rc));
     return rc;
   }
 
   zx_info_process_t Info;
-  if ((rc = Process.get_info(ZX_INFO_PROCESS, &Info, sizeof(Info), nullptr,
-                             nullptr)) != ZX_OK) {
+  if ((rc = _zx_object_get_info(ProcessHandle, ZX_INFO_PROCESS, &Info,
+                                sizeof(Info), nullptr, nullptr)) != ZX_OK) {
     Printf("libFuzzer: unable to get return code from '%s': %s\n", Argv[0],
            zx_status_get_string(rc));
     return rc;
   }
 
   return Info.return_code;
 }
 
 const void *SearchMemory(const void *Data, size_t DataLen, const void *Patt,
                          size_t PattLen) {
   return memmem(Data, DataLen, Patt, PattLen);
 }
 
 } // namespace fuzzer
 
 #endif // LIBFUZZER_FUCHSIA