Copy fbjni library from react-native

lib/fb/lyra/lyra.cpp

@@ -0,0 +1,120 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include <fb/lyra.h>
+
+#include <ios>
+#include <memory>
+#include <vector>
+
+#include <dlfcn.h>
+#include <unwind.h>
+
+using namespace std;
+
+namespace facebook {
+namespace lyra {
+
+namespace {
+
+class IosFlagsSaver {
+  ios_base& ios_;
+  ios_base::fmtflags flags_;
+
+ public:
+  IosFlagsSaver(ios_base& ios)
+  : ios_(ios),
+    flags_(ios.flags())
+  {}
+
+  ~IosFlagsSaver() {
+    ios_.flags(flags_);
+  }
+};
+
+struct BacktraceState {
+  size_t skip;
+  vector<InstructionPointer>& stackTrace;
+};
+
+_Unwind_Reason_Code unwindCallback(struct _Unwind_Context* context, void* arg) {
+  BacktraceState* state = reinterpret_cast<BacktraceState*>(arg);
+  auto absoluteProgramCounter =
+      reinterpret_cast<InstructionPointer>(_Unwind_GetIP(context));
+
+  if (state->skip > 0) {
+    --state->skip;
+    return _URC_NO_REASON;
+  }
+
+  if (state->stackTrace.size() == state->stackTrace.capacity()) {
+    return _URC_END_OF_STACK;
+  }
+
+  state->stackTrace.push_back(absoluteProgramCounter);
+
+  return _URC_NO_REASON;
+}
+
+void captureBacktrace(size_t skip, vector<InstructionPointer>& stackTrace) {
+  // Beware of a bug on some platforms, which makes the trace loop until the
+  // buffer is full when it reaches a noexcept function. It seems to be fixed in
+  // newer versions of gcc. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56846
+  // TODO(t10738439): Investigate workaround for the stack trace bug
+  BacktraceState state = {skip, stackTrace};
+  _Unwind_Backtrace(unwindCallback, &state);
+}
+}
+
+void getStackTrace(vector<InstructionPointer>& stackTrace, size_t skip) {
+  stackTrace.clear();
+  captureBacktrace(skip + 1, stackTrace);
+}
+
+// TODO(t10737622): Improve on-device symbolification
+void getStackTraceSymbols(vector<StackTraceElement>& symbols,
+                          const vector<InstructionPointer>& trace) {
+  symbols.clear();
+  symbols.reserve(trace.size());
+
+  for (size_t i = 0; i < trace.size(); ++i) {
+    Dl_info info;
+    if (dladdr(trace[i], &info)) {
+      symbols.emplace_back(trace[i], info.dli_fbase, info.dli_saddr,
+                           info.dli_fname ? info.dli_fname : "",
+                           info.dli_sname ? info.dli_sname : "");
+    }
+  }
+}
+
+ostream& operator<<(ostream& out, const StackTraceElement& elm) {
+  IosFlagsSaver flags{out};
+
+  // TODO(t10748683): Add build id to the output
+  out << "{dso=" << elm.libraryName() << " offset=" << hex
+      << showbase << elm.libraryOffset();
+
+  if (!elm.functionName().empty()) {
+    out << " func=" << elm.functionName() << "()+" << elm.functionOffset();
+  }
+
+  out << " build-id=" << hex << setw(8) << 0
+      << "}";
+
+  return out;
+}
+
+// TODO(t10737667): The implement a tool that parse the stack trace and
+// symbolicate it
+ostream& operator<<(ostream& out, const vector<StackTraceElement>& trace) {
+  IosFlagsSaver flags{out};
+
+  auto i = 0;
+  out << "Backtrace:\n";
+  for (auto& elm : trace) {
+    out << "    #" << dec << setfill('0') << setw(2) << i++ << " " << elm << '\n';
+  }
+
+  return out;
+}
+}
+}