From 6e5887e7e6f5d7aa8bd85074788090de0378dcb0 Mon Sep 17 00:00:00 2001
From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Tue, 4 Mar 2014 22:13:07 +0000
Subject: [PATCH] Remove dependence on std::function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202902 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/CrashRecoveryContext.h | 25 +++++++++++++++++----
 lib/Support/CrashRecoveryContext.cpp        | 21 +++++------------
 2 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/include/llvm/Support/CrashRecoveryContext.h b/include/llvm/Support/CrashRecoveryContext.h
index aa5e55eeab4..4500efe7b8b 100644
--- a/include/llvm/Support/CrashRecoveryContext.h
+++ b/include/llvm/Support/CrashRecoveryContext.h
@@ -10,7 +10,6 @@
 #ifndef LLVM_SUPPORT_CRASHRECOVERYCONTEXT_H
 #define LLVM_SUPPORT_CRASHRECOVERYCONTEXT_H
 
-#include <functional>
 #include <string>
 
 namespace llvm {
@@ -47,6 +46,17 @@ class CrashRecoveryContext {
   void *Impl;
   CrashRecoveryContextCleanup *head;
 
+  /// An adaptor to convert an arbitrary functor into a void(void*), void* pair.
+  template<typename T> struct FunctorAdaptor {
+    T Fn;
+    static void invoke(void *Data) {
+      return static_cast<FunctorAdaptor<T>*>(Data)->Fn();
+    }
+    typedef void Callback(void*);
+    Callback *fn() { return &invoke; }
+    void *arg() { return this; }
+  };
+
 public:
   CrashRecoveryContext() : Impl(0), head(0) {}
   ~CrashRecoveryContext();
@@ -76,8 +86,12 @@ public:
   /// make as little assumptions as possible about the program state when
   /// RunSafely has returned false. Clients can use getBacktrace() to retrieve
   /// the backtrace of the crash on failures.
-  bool RunSafely(std::function<void()> Fn);
   bool RunSafely(void (*Fn)(void*), void *UserData);
+  template<typename Functor>
+  bool RunSafely(Functor Fn) {
+    FunctorAdaptor<Functor> Adaptor = { Fn };
+    return RunSafely(Adaptor.fn(), Adaptor.arg());
+  }
 
   /// \brief Execute the provide callback function (with the given arguments) in
   /// a protected context which is run in another thread (optionally with a
@@ -86,8 +100,11 @@ public:
   /// See RunSafely() and llvm_execute_on_thread().
   bool RunSafelyOnThread(void (*Fn)(void*), void *UserData,
                          unsigned RequestedStackSize = 0);
-  bool RunSafelyOnThread(std::function<void()> Fn,
-                         unsigned RequestedStackSize = 0);
+  template<typename Functor>
+  bool RunSafelyOnThread(Functor Fn, unsigned RequestedStackSize = 0) {
+    FunctorAdaptor<Functor> Adaptor = { Fn };
+    return RunSafelyOnThread(Adaptor.fn(), Adaptor.arg(), RequestedStackSize);
+  }
 
   /// \brief Explicitly trigger a crash recovery in the current process, and
   /// return failure from RunSafely(). This function does not return.
diff --git a/lib/Support/CrashRecoveryContext.cpp b/lib/Support/CrashRecoveryContext.cpp
index 614980f718a..ccc00894fb3 100644
--- a/lib/Support/CrashRecoveryContext.cpp
+++ b/lib/Support/CrashRecoveryContext.cpp
@@ -302,10 +302,6 @@ void CrashRecoveryContext::Disable() {
 #endif
 
 bool CrashRecoveryContext::RunSafely(void (*Fn)(void*), void *UserData) {
-  return RunSafely([&]() { Fn(UserData); });
-}
-
-bool CrashRecoveryContext::RunSafely(std::function<void()> Fn) {
   // If crash recovery is disabled, do nothing.
   if (gCrashRecoveryEnabled) {
     assert(!Impl && "Crash recovery context already initialized!");
@@ -317,7 +313,7 @@ bool CrashRecoveryContext::RunSafely(std::function<void()> Fn) {
     }
   }
 
-  Fn();
+  Fn(UserData);
   return true;
 }
 
@@ -336,14 +332,10 @@ const std::string &CrashRecoveryContext::getBacktrace() const {
 
 //
 
-bool CrashRecoveryContext::RunSafelyOnThread(void (*Fn)(void*), void *UserData,
-                                             unsigned RequestedStackSize) {
-  return RunSafelyOnThread([&]() { Fn(UserData); }, RequestedStackSize);
-}
-
 namespace {
 struct RunSafelyOnThreadInfo {
-  std::function<void()> Fn;
+  void (*Fn)(void*);
+  void *Data;
   CrashRecoveryContext *CRC;
   bool Result;
 };
@@ -352,12 +344,11 @@ struct RunSafelyOnThreadInfo {
 static void RunSafelyOnThread_Dispatch(void *UserData) {
   RunSafelyOnThreadInfo *Info =
     reinterpret_cast<RunSafelyOnThreadInfo*>(UserData);
-  Info->Result = Info->CRC->RunSafely(Info->Fn);
+  Info->Result = Info->CRC->RunSafely(Info->Fn, Info->Data);
 }
-
-bool CrashRecoveryContext::RunSafelyOnThread(std::function<void()> Fn,
+bool CrashRecoveryContext::RunSafelyOnThread(void (*Fn)(void*), void *UserData,
                                              unsigned RequestedStackSize) {
-  RunSafelyOnThreadInfo Info = { Fn, this, false };
+  RunSafelyOnThreadInfo Info = { Fn, UserData, this, false };
   llvm_execute_on_thread(RunSafelyOnThread_Dispatch, &Info, RequestedStackSize);
   if (CrashRecoveryContextImpl *CRC = (CrashRecoveryContextImpl *)Impl)
     CRC->setSwitchedThread();