Import LLVM, at r72732.

1 files changed, 214 insertions, 0 deletions

diff --git a/lib/Bitcode/Reader/BitcodeReader.h b/lib/Bitcode/Reader/BitcodeReader.h
new file mode 100644
index 0000000..0dc470b
--- /dev/null
+++ b/lib/Bitcode/Reader/BitcodeReader.h
@@ -0,0 +1,214 @@
+//===- BitcodeReader.h - Internal BitcodeReader impl ------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This header defines the BitcodeReader class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef BITCODE_READER_H
+#define BITCODE_READER_H
+
+#include "llvm/ModuleProvider.h"
+#include "llvm/Attributes.h"
+#include "llvm/Type.h"
+#include "llvm/OperandTraits.h"
+#include "llvm/Bitcode/BitstreamReader.h"
+#include "llvm/Bitcode/LLVMBitCodes.h"
+#include "llvm/Support/ValueHandle.h"
+#include "llvm/ADT/DenseMap.h"
+#include <vector>
+
+namespace llvm {
+  class MemoryBuffer;
+  
+//===----------------------------------------------------------------------===//
+//                          BitcodeReaderValueList Class
+//===----------------------------------------------------------------------===//
+
+class BitcodeReaderValueList {
+  std::vector<WeakVH> ValuePtrs;
+  
+  /// ResolveConstants - As we resolve forward-referenced constants, we add
+  /// information about them to this vector.  This allows us to resolve them in
+  /// bulk instead of resolving each reference at a time.  See the code in
+  /// ResolveConstantForwardRefs for more information about this.
+  ///
+  /// The key of this vector is the placeholder constant, the value is the slot
+  /// number that holds the resolved value.
+  typedef std::vector<std::pair<Constant*, unsigned> > ResolveConstantsTy;
+  ResolveConstantsTy ResolveConstants;
+public:
+  BitcodeReaderValueList() {}
+  ~BitcodeReaderValueList() {
+    assert(ResolveConstants.empty() && "Constants not resolved?");
+  }
+
+  // vector compatibility methods
+  unsigned size() const { return ValuePtrs.size(); }
+  void resize(unsigned N) { ValuePtrs.resize(N); }
+  void push_back(Value *V) {
+    ValuePtrs.push_back(V);
+  }
+  
+  void clear() {
+    assert(ResolveConstants.empty() && "Constants not resolved?");
+    ValuePtrs.clear();
+  }
+  
+  Value *operator[](unsigned i) const {
+    assert(i < ValuePtrs.size());
+    return ValuePtrs[i];
+  }
+  
+  Value *back() const { return ValuePtrs.back(); }
+    void pop_back() { ValuePtrs.pop_back(); }
+  bool empty() const { return ValuePtrs.empty(); }
+  void shrinkTo(unsigned N) {
+    assert(N <= size() && "Invalid shrinkTo request!");
+    ValuePtrs.resize(N);
+  }
+  
+  Constant *getConstantFwdRef(unsigned Idx, const Type *Ty);
+  Value *getValueFwdRef(unsigned Idx, const Type *Ty);
+  
+  void AssignValue(Value *V, unsigned Idx);
+  
+  /// ResolveConstantForwardRefs - Once all constants are read, this method bulk
+  /// resolves any forward references.
+  void ResolveConstantForwardRefs();
+};
+
+class BitcodeReader : public ModuleProvider {
+  MemoryBuffer *Buffer;
+  BitstreamReader StreamFile;
+  BitstreamCursor Stream;
+  
+  const char *ErrorString;
+  
+  std::vector<PATypeHolder> TypeList;
+  BitcodeReaderValueList ValueList;
+  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
+  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
+  
+  /// MAttributes - The set of attributes by index.  Index zero in the
+  /// file is for null, and is thus not represented here.  As such all indices
+  /// are off by one.
+  std::vector<AttrListPtr> MAttributes;
+  
+  /// FunctionBBs - While parsing a function body, this is a list of the basic
+  /// blocks for the function.
+  std::vector<BasicBlock*> FunctionBBs;
+  
+  // When reading the module header, this list is populated with functions that
+  // have bodies later in the file.
+  std::vector<Function*> FunctionsWithBodies;
+
+  // When intrinsic functions are encountered which require upgrading they are 
+  // stored here with their replacement function.
+  typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap;
+  UpgradedIntrinsicMap UpgradedIntrinsics;
+  
+  // After the module header has been read, the FunctionsWithBodies list is 
+  // reversed.  This keeps track of whether we've done this yet.
+  bool HasReversedFunctionsWithBodies;
+  
+  /// DeferredFunctionInfo - When function bodies are initially scanned, this
+  /// map contains info about where to find deferred function body (in the
+  /// stream) and what linkage the original function had.
+  DenseMap<Function*, std::pair<uint64_t, unsigned> > DeferredFunctionInfo;
+public:
+  explicit BitcodeReader(MemoryBuffer *buffer)
+      : Buffer(buffer), ErrorString(0) {
+    HasReversedFunctionsWithBodies = false;
+  }
+  ~BitcodeReader() {
+    FreeState();
+  }
+  
+  void FreeState();
+  
+  /// releaseMemoryBuffer - This causes the reader to completely forget about
+  /// the memory buffer it contains, which prevents the buffer from being
+  /// destroyed when it is deleted.
+  void releaseMemoryBuffer() {
+    Buffer = 0;
+  }
+  
+  virtual bool materializeFunction(Function *F, std::string *ErrInfo = 0);
+  virtual Module *materializeModule(std::string *ErrInfo = 0);
+  virtual void dematerializeFunction(Function *F);
+  virtual Module *releaseModule(std::string *ErrInfo = 0);
+
+  bool Error(const char *Str) {
+    ErrorString = Str;
+    return true;
+  }
+  const char *getErrorString() const { return ErrorString; }
+  
+  /// @brief Main interface to parsing a bitcode buffer.
+  /// @returns true if an error occurred.
+  bool ParseBitcode();
+private:
+  const Type *getTypeByID(unsigned ID, bool isTypeTable = false);
+  Value *getFnValueByID(unsigned ID, const Type *Ty) {
+    return ValueList.getValueFwdRef(ID, Ty);
+  }
+  BasicBlock *getBasicBlock(unsigned ID) const {
+    if (ID >= FunctionBBs.size()) return 0; // Invalid ID
+    return FunctionBBs[ID];
+  }
+  AttrListPtr getAttributes(unsigned i) const {
+    if (i-1 < MAttributes.size())
+      return MAttributes[i-1];
+    return AttrListPtr();
+  }
+  
+  /// getValueTypePair - Read a value/type pair out of the specified record from
+  /// slot 'Slot'.  Increment Slot past the number of slots used in the record.
+  /// Return true on failure.
+  bool getValueTypePair(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
+                        unsigned InstNum, Value *&ResVal) {
+    if (Slot == Record.size()) return true;
+    unsigned ValNo = (unsigned)Record[Slot++];
+    if (ValNo < InstNum) {
+      // If this is not a forward reference, just return the value we already
+      // have.
+      ResVal = getFnValueByID(ValNo, 0);
+      return ResVal == 0;
+    } else if (Slot == Record.size()) {
+      return true;
+    }
+    
+    unsigned TypeNo = (unsigned)Record[Slot++];
+    ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
+    return ResVal == 0;
+  }
+  bool getValue(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
+                const Type *Ty, Value *&ResVal) {
+    if (Slot == Record.size()) return true;
+    unsigned ValNo = (unsigned)Record[Slot++];
+    ResVal = getFnValueByID(ValNo, Ty);
+    return ResVal == 0;
+  }
+
+  
+  bool ParseModule(const std::string &ModuleID);
+  bool ParseAttributeBlock();
+  bool ParseTypeTable();
+  bool ParseTypeSymbolTable();
+  bool ParseValueSymbolTable();
+  bool ParseConstants();
+  bool RememberAndSkipFunctionBody();
+  bool ParseFunctionBody(Function *F);
+  bool ResolveGlobalAndAliasInits();
+};
+  
+} // End llvm namespace
+
+#endif