From 14e3467b5ca0ba4235b0febd9ef13e421ab3ca72 Mon Sep 17 00:00:00 2001
From: Micah Kornfield <emkornfield@gmail.com>
Date: Sat, 22 Jun 2019 03:14:20 -0700
Subject: [PATCH] dont rely on rtti

---
 cpp/src/arrow/python/common.cc | 6 ++++--
 cpp/src/arrow/status-test.cc   | 1 +
 cpp/src/arrow/status.h         | 3 +++
 cpp/src/plasma/common.cc       | 9 ++++++---
 4 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/cpp/src/arrow/python/common.cc b/cpp/src/arrow/python/common.cc
index 5a6cf54f69ab3..ad7864697e5f2 100644
--- a/cpp/src/arrow/python/common.cc
+++ b/cpp/src/arrow/python/common.cc
@@ -51,12 +51,14 @@ MemoryPool* get_memory_pool() {
 // PythonErroDetail
 namespace {
 
+const char kErrorDetailTypeId[] = "existing exception on python static status.";
 // PythonErrorDetail indicates a python exception was raised and not
 // reset in C++ code (i.e. it should be propagated up through the python
 // stack).
 class PythonErrorDetail : public StatusDetail {
  public:
   PythonErrorDetail() = default;
+  const char* type_id() const override { return kErrorDetailTypeId; }
   std::string ToString() const override { return "Python Error."; }
 };
 
@@ -157,8 +159,8 @@ bool IsPythonError(const Status& status) {
   if (status.ok()) {
     return false;
   }
-  auto detail = dynamic_cast<PythonErrorDetail*>(status.detail().get());
-  return detail != nullptr;
+  auto detail = status.detail().get();
+  return detail != nullptr && detail->type_id() == kErrorDetailTypeId;
 }
 
 }  // namespace py
diff --git a/cpp/src/arrow/status-test.cc b/cpp/src/arrow/status-test.cc
index eb8ad93ddde40..b151e462b2803 100644
--- a/cpp/src/arrow/status-test.cc
+++ b/cpp/src/arrow/status-test.cc
@@ -27,6 +27,7 @@ namespace {
 
 class TestStatusDetail : public StatusDetail {
  public:
+  const char* type_id() const override { return "type_id"; }
   std::string ToString() const override { return "a specific detail message"; }
 };
 
diff --git a/cpp/src/arrow/status.h b/cpp/src/arrow/status.h
index 46c329a6b71b2..7cafc41902df2 100644
--- a/cpp/src/arrow/status.h
+++ b/cpp/src/arrow/status.h
@@ -105,6 +105,9 @@ class ARROW_MUST_USE_RESULT ARROW_EXPORT Status;
 class ARROW_EXPORT StatusDetail {
  public:
   virtual ~StatusDetail() = default;
+  // Return a unique id for the type of the StatusDetail
+  // (effectively a poor man's substitude for RTTI).
+  virtual const char* type_id() const = 0;
   virtual std::string ToString() const = 0;
 };
 
diff --git a/cpp/src/plasma/common.cc b/cpp/src/plasma/common.cc
index 32cd05a5a8def..84a1601952e80 100644
--- a/cpp/src/plasma/common.cc
+++ b/cpp/src/plasma/common.cc
@@ -30,10 +30,12 @@ namespace plasma {
 
 namespace {
 
+const char kErrorDetailTypeId[] = "plasma status detail";
+
 class PlasmaStatusDetail : public arrow::StatusDetail {
  public:
   explicit PlasmaStatusDetail(PlasmaErrorCode code) : code_(code) {}
-
+  const char* type_id() const override { return kErrorDetailTypeId; }
   std::string ToString() const override {
     const char* type;
     switch (code()) {
@@ -62,8 +64,9 @@ bool IsPlasmaStatus(const arrow::Status& status, PlasmaErrorCode code) {
   if (status.ok()) {
     return false;
   }
-  auto* detail = dynamic_cast<PlasmaStatusDetail*>(status.detail().get());
-  return detail != nullptr && detail->code() == code;
+  auto* detail = status.detail().get();
+  return detail != nullptr && detail->type_id() == kErrorDetailTypeId &&
+         static_cast<PlasmaStatusDetail*>(detail)->code() == code;
 }
 
 }  // namespace