4 files changed, 110 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index d7995447592..7ffb5ddc2d6 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -16,6 +16,7 @@
 #include "CodeViewDebug.h"
 #include "DwarfDebug.h"
 #include "DwarfException.h"
+#include "WinCFGuard.h"
 #include "WinException.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APInt.h"
@@ -130,6 +131,8 @@ static const char *const DbgTimerName = "emit";
 static const char *const DbgTimerDescription = "Debug Info Emission";
 static const char *const EHTimerName = "write_exception";
 static const char *const EHTimerDescription = "DWARF Exception Writer";
+static const char *const CFGuardName = "Control Flow Guard";
+static const char *const CFGuardDescription = "Control Flow Guard Tables";
 static const char *const CodeViewLineTablesGroupName = "linetables";
 static const char *const CodeViewLineTablesGroupDescription =
   "CodeView Line Tables";
@@ -354,6 +357,13 @@ bool AsmPrinter::doInitialization(Module &M) {
   if (ES)
     Handlers.push_back(HandlerInfo(ES, EHTimerName, EHTimerDescription,
                                    DWARFGroupName, DWARFGroupDescription));
+
+  if (mdconst::extract_or_null<ConstantInt>(
+          MMI->getModule()->getModuleFlag("cfguard")))
+    Handlers.push_back(HandlerInfo(new WinCFGuard(this), CFGuardName,
+                                   CFGuardDescription, DWARFGroupName,
+                                   DWARFGroupDescription));
+
   return false;
 }
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt b/llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt
index 05c6a28bbca..f21810f0b05 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt
+++ b/llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt
@@ -20,6 +20,7 @@ add_llvm_library(LLVMAsmPrinter
   EHStreamer.cpp
   ErlangGCPrinter.cpp
   OcamlGCPrinter.cpp
+  WinCFGuard.cpp
   WinException.cpp
   CodeViewDebug.cpp
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/WinCFGuard.cpp b/llvm/lib/CodeGen/AsmPrinter/WinCFGuard.cpp
new file mode 100644
index 00000000000..18d37caf57e
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/WinCFGuard.cpp
@@ -0,0 +1,45 @@
+//===-- CodeGen/AsmPrinter/WinCFGuard.cpp - Control Flow Guard Impl ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for writing Win64 exception info into asm files.
+//
+//===----------------------------------------------------------------------===//
+
+#include "WinCFGuard.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineOperand.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCObjectFileInfo.h"
+#include "llvm/MC/MCStreamer.h"
+
+#include <vector>
+
+using namespace llvm;
+
+WinCFGuard::WinCFGuard(AsmPrinter *A) : AsmPrinterHandler(), Asm(A) {}
+
+WinCFGuard::~WinCFGuard() {}
+
+void WinCFGuard::endModule() {
+  const Module *M = Asm->MMI->getModule();
+  std::vector<const Function *> Functions;
+  for (const Function &F : *M)
+    if (F.hasAddressTaken())
+      Functions.push_back(&F);
+  if (Functions.empty())
+    return;
+  auto &OS = *Asm->OutStreamer;
+  OS.SwitchSection(Asm->OutContext.getObjectFileInfo()->getGFIDsSection());
+  for (const Function *F : Functions)
+    OS.EmitCOFFSymbolIndex(Asm->getSymbol(F));
+}
diff --git a/llvm/lib/CodeGen/AsmPrinter/WinCFGuard.h b/llvm/lib/CodeGen/AsmPrinter/WinCFGuard.h
new file mode 100644
index 00000000000..553b4ae261c
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/WinCFGuard.h
@@ -0,0 +1,54 @@
+//===-- WinCFGuard.h - Windows Control Flow Guard Handling ----*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for writing windows exception info into asm files.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_WINCFGUARD_H
+#define LLVM_LIB_CODEGEN_ASMPRINTER_WINCFGUARD_H
+
+#include "AsmPrinterHandler.h"
+#include "llvm/Support/Compiler.h"
+
+namespace llvm {
+
+class LLVM_LIBRARY_VISIBILITY WinCFGuard : public AsmPrinterHandler {
+  /// Target of directive emission.
+  AsmPrinter *Asm;
+
+public:
+  WinCFGuard(AsmPrinter *A);
+  ~WinCFGuard() override;
+
+  void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override {}
+
+  /// \brief Emit the Control Flow Guard function ID table
+  void endModule() override;
+
+  /// \brief Gather pre-function debug information.
+  /// Every beginFunction(MF) call should be followed by an endFunction(MF)
+  /// call.
+  void beginFunction(const MachineFunction *MF) override {}
+
+  /// \brief Gather post-function debug information.
+  /// Please note that some AsmPrinter implementations may not call
+  /// beginFunction at all.
+  void endFunction(const MachineFunction *MF) override {}
+
+  /// \brief Process beginning of an instruction.
+  void beginInstruction(const MachineInstr *MI) override {}
+
+  /// \brief Process end of an instruction.
+  void endInstruction() override {}
+};
+
+} // namespace llvm
+
+#endif