1 files changed, 66 insertions, 31 deletions

diff --git a/contrib/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc b/contrib/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
index fc8a7d9..7028da6 100644
--- a/contrib/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
+++ b/contrib/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
@@ -26,7 +26,9 @@
 #include "sanitizer_symbolizer_libbacktrace.h"
 #include "sanitizer_symbolizer_mac.h"
 
+#include <dlfcn.h>   // for dlsym()
 #include <errno.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <sys/wait.h>
 #include <unistd.h>
@@ -61,6 +63,44 @@ const char *DemangleCXXABI(const char *name) {
   return name;
 }
 
+// As of now, there are no headers for the Swift runtime. Once they are
+// present, we will weakly link since we do not require Swift runtime to be
+// linked.
+typedef char *(*swift_demangle_ft)(const char *mangledName,
+                                   size_t mangledNameLength, char *outputBuffer,
+                                   size_t *outputBufferSize, uint32_t flags);
+static swift_demangle_ft swift_demangle_f;
+
+// This must not happen lazily at symbolication time, because dlsym uses
+// malloc and thread-local storage, which is not a good thing to do during
+// symbolication.
+static void InitializeSwiftDemangler() {
+  swift_demangle_f = (swift_demangle_ft)dlsym(RTLD_DEFAULT, "swift_demangle");
+}
+
+// Attempts to demangle a Swift name. The demangler will return nullptr if a
+// non-Swift name is passed in.
+const char *DemangleSwift(const char *name) {
+  if (!name) return nullptr;
+
+  // Check if we are dealing with a Swift mangled name first.
+  if (name[0] != '_' || name[1] != 'T') {
+    return nullptr;
+  }
+
+  if (swift_demangle_f)
+    return swift_demangle_f(name, internal_strlen(name), 0, 0, 0);
+
+  return nullptr;
+}
+
+const char *DemangleSwiftAndCXX(const char *name) {
+  if (!name) return nullptr;
+  if (const char *swift_demangled_name = DemangleSwift(name))
+    return swift_demangled_name;
+  return DemangleCXXABI(name);
+}
+
 bool SymbolizerProcess::StartSymbolizerSubprocess() {
   if (!FileExists(path_)) {
     if (!reported_invalid_path_) {
@@ -74,6 +114,13 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
   if (use_forkpty_) {
 #if SANITIZER_MAC
     fd_t fd = kInvalidFd;
+
+    // forkpty redirects stdout and stderr into a single stream, so we would
+    // receive error messages as standard replies. To avoid that, let's dup
+    // stderr and restore it in the child.
+    int saved_stderr = dup(STDERR_FILENO);
+    CHECK_GE(saved_stderr, 0);
+
     // Use forkpty to disable buffering in the new terminal.
     pid = internal_forkpty(&fd);
     if (pid == -1) {
@@ -83,6 +130,11 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
       return false;
     } else if (pid == 0) {
       // Child subprocess.
+
+      // Restore stderr.
+      CHECK_GE(dup2(saved_stderr, STDERR_FILENO), 0);
+      close(saved_stderr);
+
       const char *argv[kArgVMax];
       GetArgV(path_, argv);
       execv(path_, const_cast<char **>(&argv[0]));
@@ -92,6 +144,8 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
     // Continue execution in parent process.
     input_fd_ = output_fd_ = fd;
 
+    close(saved_stderr);
+
     // Disable echo in the new terminal, disable CR.
     struct termios termflags;
     tcgetattr(fd, &termflags);
@@ -137,47 +191,23 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
     CHECK(infd);
     CHECK(outfd);
 
-    // Real fork() may call user callbacks registered with pthread_atfork().
-    pid = internal_fork();
-    if (pid == -1) {
-      // Fork() failed.
+    const char *argv[kArgVMax];
+    GetArgV(path_, argv);
+    pid = StartSubprocess(path_, argv, /* stdin */ outfd[0],
+                          /* stdout */ infd[1]);
+    if (pid < 0) {
       internal_close(infd[0]);
-      internal_close(infd[1]);
-      internal_close(outfd[0]);
       internal_close(outfd[1]);
-      Report("WARNING: failed to fork external symbolizer "
-             " (errno: %d)\n", errno);
       return false;
-    } else if (pid == 0) {
-      // Child subprocess.
-      internal_close(STDOUT_FILENO);
-      internal_close(STDIN_FILENO);
-      internal_dup2(outfd[0], STDIN_FILENO);
-      internal_dup2(infd[1], STDOUT_FILENO);
-      internal_close(outfd[0]);
-      internal_close(outfd[1]);
-      internal_close(infd[0]);
-      internal_close(infd[1]);
-      for (int fd = sysconf(_SC_OPEN_MAX); fd > 2; fd--)
-        internal_close(fd);
-      const char *argv[kArgVMax];
-      GetArgV(path_, argv);
-      execv(path_, const_cast<char **>(&argv[0]));
-      internal__exit(1);
     }
 
-    // Continue execution in parent process.
-    internal_close(outfd[0]);
-    internal_close(infd[1]);
     input_fd_ = infd[0];
     output_fd_ = outfd[1];
   }
 
   // Check that symbolizer subprocess started successfully.
-  int pid_status;
   SleepForMillis(kSymbolizerStartupTimeMillis);
-  int exited_pid = waitpid(pid, &pid_status, WNOHANG);
-  if (exited_pid != 0) {
+  if (!IsProcessRunning(pid)) {
     // Either waitpid failed, or child has already exited.
     Report("WARNING: external symbolizer didn't start up correctly!\n");
     return false;
@@ -374,7 +404,7 @@ class InternalSymbolizer : public SymbolizerTool {
 #endif  // SANITIZER_SUPPORTS_WEAK_HOOKS
 
 const char *Symbolizer::PlatformDemangle(const char *name) {
-  return DemangleCXXABI(name);
+  return DemangleSwiftAndCXX(name);
 }
 
 void Symbolizer::PlatformPrepareForSandboxing() {}
@@ -461,6 +491,11 @@ Symbolizer *Symbolizer::PlatformInit() {
   return new(symbolizer_allocator_) Symbolizer(list);
 }
 
+void Symbolizer::LateInitialize() {
+  Symbolizer::GetOrInit();
+  InitializeSwiftDemangler();
+}
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_POSIX