Add a header containing definitions used to implement Win64 exception handling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131380 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/Win64EH.h

@@ -0,0 +1,100 @@
+//===-- llvm/Support/Win64EH.h ---Win64 EH Constants-------------*- 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 constants and structures used for implementing
+// exception handling on Win64 platforms. For more information, see
+// http://msdn.microsoft.com/en-us/library/1eyas8tf.aspx
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_WIN64EH_H
+#define LLVM_SUPPORT_WIN64EH_H
+
+namespace llvm {
+namespace Win64EH {
+
+extern "C" {
+
+/// UnwindOpcodes - Enumeration whose values specify a single operation in
+/// the prolog of a function.
+enum UnwindOpcodes {
+  UOP_PushNonVol = 0,
+  UOP_AllocLarge,
+  UOP_AllocSmall,
+  UOP_SetFPReg,
+  UOP_SaveNonVol,
+  UOP_SaveNonVolBig,
+  UOP_SaveXMM128,
+  UOP_SaveXMM128Big,
+  UOP_PushMachFrame
+};
+
+/// UnwindCode - This union describes a single operation in a function prolog,
+/// or part thereof.
+union UnwindCode {
+  struct {
+    uint8_t codeOffset;
+    uint8_t unwindOp:4,
+            opInfo:4;
+  };
+  uint16_t frameOffset;
+};
+
+enum {
+  /// UNW_ExceptionHandler - Specifies that this function has an exception
+  /// handler.
+  UNW_ExceptionHandler = 0x01,
+  /// UNW_TerminateHandler - Specifies that this function has a termination
+  /// handler.
+  UNW_TerminateHandler = 0x02,
+  /// UNW_ChainInfo - Specifies that this UnwindInfo structure is chained to
+  /// another one.
+  UNW_ChainInfo = 0x04
+};
+
+/// UnwindInfo - An entry in the exception table.
+struct UnwindInfo {
+  uint8_t version:3,
+          flags:5;
+  uint8_t prologSize;
+  uint8_t numCodes;
+  uint8_t frameRegister:4,
+          frameOffset:4;
+  UnwindCode unwindCodes[1];
+};
+
+inline UnwindCode &getUnwindCodeEntry(UnwindInfo &info, uint32_t index) {
+  return info.unwindCodes[index];
+}
+inline void *getLanguageSpecificData(UnwindInfo &info) {
+  return reinterpret_cast<void *>(&getUnwindCodeEntry(info,info.numCodes+1)&~1);
+}
+inline uint64_t getLanguageSpecificHandlerOffset(UnwindInfo &info) {
+  return *reinterpret_cast<uint64_t *>(getLangaugeSpecificData(info));
+}
+inline void setLanguageSpecificHandlerOffset(UnwindInfo &info, uint64_t offset){
+  *reinterpret_cast<uint64_t *>(getLanguageSpecificData(info)) = offset;
+}
+inline uint64_t getChainedFunctionEntryOffset(UnwindInfo &info) {
+  return *reinterpret_cast<uint64_t *>(getLanguageSpecificData(info));
+}
+inline void setChainedFunctionEntryOffset(UnwindInfo &info, uint64_t offset) {
+  *reinterpret_cast<uint64_t *>(getLanguageSpecificData(info)) = offset;
+}
+inline void *getExceptionData(UnwindInfo &info) {
+  return reinterpret_cast<void *>(reinterpret_cast<uint64_t *>(
+                                              getLanguageSpecificData(info))+1);
+}
+
+} // End of extern "C"
+
+} // End of namespace Win64EH
+} // End of namespace llvm
+
+#endif