vendor/llvm/llvm-r72732

1 files changed, 178 insertions, 0 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfException.h b/lib/CodeGen/AsmPrinter/DwarfException.h
new file mode 100644
index 000000000000..4479af243e90
--- /dev/null
+++ b/lib/CodeGen/AsmPrinter/DwarfException.h
@@ -0,0 +1,178 @@
+//===-- DwarfException.h - Dwarf Exception Framework -----------*- 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 dwarf exception info into asm files.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CODEGEN_ASMPRINTER_DWARFEXCEPTION_H__
+#define CODEGEN_ASMPRINTER_DWARFEXCEPTION_H__
+
+#include "DIE.h"
+#include "DwarfPrinter.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/ADT/DenseMap.h"
+#include <string>
+
+namespace llvm {
+
+struct LandingPadInfo;
+class MachineModuleInfo;
+class TargetAsmInfo;
+class Timer;
+class raw_ostream;
+
+//===----------------------------------------------------------------------===//
+/// DwarfException - Emits Dwarf exception handling directives.
+///
+class VISIBILITY_HIDDEN DwarfException : public Dwarf {
+  struct FunctionEHFrameInfo {
+    std::string FnName;
+    unsigned Number;
+    unsigned PersonalityIndex;
+    bool hasCalls;
+    bool hasLandingPads;
+    std::vector<MachineMove> Moves;
+    const Function * function;
+
+    FunctionEHFrameInfo(const std::string &FN, unsigned Num, unsigned P,
+                        bool hC, bool hL,
+                        const std::vector<MachineMove> &M,
+                        const Function *f):
+      FnName(FN), Number(Num), PersonalityIndex(P),
+      hasCalls(hC), hasLandingPads(hL), Moves(M), function (f) { }
+  };
+
+  std::vector<FunctionEHFrameInfo> EHFrames;
+
+  /// shouldEmitTable - Per-function flag to indicate if EH tables should
+  /// be emitted.
+  bool shouldEmitTable;
+
+  /// shouldEmitMoves - Per-function flag to indicate if frame moves info
+  /// should be emitted.
+  bool shouldEmitMoves;
+
+  /// shouldEmitTableModule - Per-module flag to indicate if EH tables
+  /// should be emitted.
+  bool shouldEmitTableModule;
+
+  /// shouldEmitFrameModule - Per-module flag to indicate if frame moves
+  /// should be emitted.
+  bool shouldEmitMovesModule;
+
+  /// ExceptionTimer - Timer for the Dwarf exception writer.
+  Timer *ExceptionTimer;
+
+  /// EmitCommonEHFrame - Emit the common eh unwind frame.
+  ///
+  void EmitCommonEHFrame(const Function *Personality, unsigned Index);
+
+  /// EmitEHFrame - Emit function exception frame information.
+  ///
+  void EmitEHFrame(const FunctionEHFrameInfo &EHFrameInfo);
+
+  /// EmitExceptionTable - Emit landing pads and actions.
+  ///
+  /// The general organization of the table is complex, but the basic concepts
+  /// are easy.  First there is a header which describes the location and
+  /// organization of the three components that follow.
+  ///  1. The landing pad site information describes the range of code covered
+  ///     by the try.  In our case it's an accumulation of the ranges covered
+  ///     by the invokes in the try.  There is also a reference to the landing
+  ///     pad that handles the exception once processed.  Finally an index into
+  ///     the actions table.
+  ///  2. The action table, in our case, is composed of pairs of type ids
+  ///     and next action offset.  Starting with the action index from the
+  ///     landing pad site, each type Id is checked for a match to the current
+  ///     exception.  If it matches then the exception and type id are passed
+  ///     on to the landing pad.  Otherwise the next action is looked up.  This
+  ///     chain is terminated with a next action of zero.  If no type id is
+  ///     found the the frame is unwound and handling continues.
+  ///  3. Type id table contains references to all the C++ typeinfo for all
+  ///     catches in the function.  This tables is reversed indexed base 1.
+
+  /// SharedTypeIds - How many leading type ids two landing pads have in common.
+  static unsigned SharedTypeIds(const LandingPadInfo *L,
+                                const LandingPadInfo *R);
+
+  /// PadLT - Order landing pads lexicographically by type id.
+  static bool PadLT(const LandingPadInfo *L, const LandingPadInfo *R);
+
+  struct KeyInfo {
+    static inline unsigned getEmptyKey() { return -1U; }
+    static inline unsigned getTombstoneKey() { return -2U; }
+    static unsigned getHashValue(const unsigned &Key) { return Key; }
+    static bool isEqual(unsigned LHS, unsigned RHS) { return LHS == RHS; }
+    static bool isPod() { return true; }
+  };
+
+  /// ActionEntry - Structure describing an entry in the actions table.
+  struct ActionEntry {
+    int ValueForTypeID; // The value to write - may not be equal to the type id.
+    int NextAction;
+    struct ActionEntry *Previous;
+  };
+
+  /// PadRange - Structure holding a try-range and the associated landing pad.
+  struct PadRange {
+    // The index of the landing pad.
+    unsigned PadIndex;
+    // The index of the begin and end labels in the landing pad's label lists.
+    unsigned RangeIndex;
+  };
+
+  typedef DenseMap<unsigned, PadRange, KeyInfo> RangeMapType;
+
+  /// CallSiteEntry - Structure describing an entry in the call-site table.
+  struct CallSiteEntry {
+    // The 'try-range' is BeginLabel .. EndLabel.
+    unsigned BeginLabel; // zero indicates the start of the function.
+    unsigned EndLabel;   // zero indicates the end of the function.
+    // The landing pad starts at PadLabel.
+    unsigned PadLabel;   // zero indicates that there is no landing pad.
+    unsigned Action;
+  };
+
+  void EmitExceptionTable();
+
+public:
+  //===--------------------------------------------------------------------===//
+  // Main entry points.
+  //
+  DwarfException(raw_ostream &OS, AsmPrinter *A, const TargetAsmInfo *T);
+  virtual ~DwarfException();
+
+  /// SetModuleInfo - Set machine module information when it's known that pass
+  /// manager has created it.  Set by the target AsmPrinter.
+  void SetModuleInfo(MachineModuleInfo *mmi) {
+    MMI = mmi;
+  }
+
+  /// BeginModule - Emit all exception information that should come prior to the
+  /// content.
+  void BeginModule(Module *M) {
+    this->M = M;
+  }
+
+  /// EndModule - Emit all exception information that should come after the
+  /// content.
+  void EndModule();
+
+  /// BeginFunction - Gather pre-function exception information.  Assumes being
+  /// emitted immediately after the function entry point.
+  void BeginFunction(MachineFunction *MF);
+
+  /// EndFunction - Gather and emit post-function exception information.
+  void EndFunction();
+};
+
+} // End of namespace llvm
+
+#endif