Add constants block to PNaCl bitcode reader.

src/PNaClTranslator.cpp

 //===- subzero/src/PNaClTranslator.cpp - ICE from bitcode -----------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the PNaCl bitcode file to Ice, to machine code
@@ skipping 803 matching lines @@
     CurrentNode = InstallNextBasicBlock();
     for (Function::const_arg_iterator ArgI = LLVMFunc->arg_begin(),
                                       ArgE = LLVMFunc->arg_end();
          ArgI != ArgE; ++ArgI) {
       Func->addArg(NextInstVar(Context->convertToIceType(ArgI->getType())));
     }
   }
 
   ~FunctionParser() LLVM_OVERRIDE;
 
+  // Set the next constant ID to the given constant C.
+  void setNextConstantID(Ice::Constant *C) {
+    LocalOperands.push_back(C);
+  }
+
 private:
   // Timer for reading function bitcode and converting to ICE.
   Ice::Timer TConvert;
   // The corresponding ICE function defined by the function block.
   Ice::Cfg *Func;
   // The index to the current basic block being built.
   uint32_t CurrentBbIndex;
   // The basic block being built.
   Ice::CfgNode *CurrentNode;
   // The ID for the function.
   unsigned FcnId;
   // The corresponding LLVM function.
   Function *LLVMFunc;
   // Holds operands local to the function block, based on indices
   // defined in the bitcode file.
   std::vector<Ice::Operand *> LocalOperands;
   // Holds the dividing point between local and global absolute value indices.
   uint32_t CachedNumGlobalValueIDs;
   // True if the last processed instruction was a terminating
   // instruction.
   bool InstIsTerminating;
 
+  virtual bool ParseBlock(unsigned BlockID) LLVM_OVERRIDE;
+
   virtual void ProcessRecord() LLVM_OVERRIDE;
 
   virtual void ExitBlock() LLVM_OVERRIDE;
 
   // Creates and appends a new basic block to the list of basic blocks.
   Ice::CfgNode *InstallNextBasicBlock() { return Func->makeNode(); }
 
   // Returns the Index-th basic block in the list of basic blocks.
   Ice::CfgNode *GetBasicBlock(uint32_t Index) {
     const Ice::NodeList &Nodes = Func->getNodes();
@@ skipping 656 matching lines @@
   }
   default:
     // Generate error message!
     BlockParserBaseClass::ProcessRecord();
     break;
   }
   if (Inst)
     CurrentNode->appendInst(Inst);
 }
 
+/// Parses constants within a function block.
+class ConstantsParser : public BlockParserBaseClass {
+  ConstantsParser(const ConstantsParser &) LLVM_DELETED_FUNCTION;
+  ConstantsParser &operator=(const ConstantsParser &) LLVM_DELETED_FUNCTION;
+
+public:
+  ConstantsParser(unsigned BlockID, FunctionParser *FuncParser)
+      : BlockParserBaseClass(BlockID, FuncParser),
+        FuncParser(FuncParser),
+        NextConstantType(Ice::IceType_void) {}
+
+  ~ConstantsParser() LLVM_OVERRIDE {}
+
+private:
+  // The parser of the function block this constants block appears in.
+  FunctionParser *FuncParser;
+  // The type to use for succeeding constants.
+  Ice::Type NextConstantType;
+
+  virtual void ProcessRecord() LLVM_OVERRIDE;
+
+  Ice::GlobalContext *getContext() {
+    return getTranslator().getContext();
+  }
+
+  // Returns true if the type to use for succeeding constants is defined.
+  // If false, also generates an error message.
+  bool isValidNextConstantType() {
+    if (NextConstantType != Ice::IceType_void) return true;

[Jim Stichnoth, 2014/09/05 23:34:29]

return on separate line, i.e. run "make format-diff"

[Karl, 2014/09/08 20:41:39]

Done.

+    Error("Constant record not preceded by set type record");
+    return false;
+  }
+};
+
+void ConstantsParser::ProcessRecord() {
+  const NaClBitcodeRecord::RecordVector &Values = Record.GetValues();
+  switch (Record.GetCode()) {
+  case naclbitc::CST_CODE_SETTYPE: {
+    // SETTYPE: [typeid]
+    if (!isValidRecordSize(1, "constants block set type")) return;
+    NextConstantType
+        = Context->convertToIceType(Context->getTypeByID(Values[0]));
+    if (NextConstantType == Ice::IceType_void)
+      Error("constants block set type not allowed for void type");
+    return;
+  }
+  case naclbitc::CST_CODE_UNDEF: {
+    // UNDEF
+    if (!isValidRecordSize(0, "constants block undef")) return;
+    if (!isValidNextConstantType()) return;
+    FuncParser->setNextConstantID(
+        getContext()->getConstantUndef(NextConstantType));
+    return;
+  }
+  case naclbitc::CST_CODE_INTEGER: {
+    // INTEGER: [intval]
+    if (!isValidRecordSize(1, "constants block integer")) return;
+    if (!isValidNextConstantType()) return;
+    if (IntegerType *IType = dyn_cast<IntegerType>(
+            Context->convertToLLVMType(NextConstantType))) {

[jvoung (off chromium), 2014/09/06 17:53:47]

Might just be able to check the IceType's typeWidthInBytes() * CHAR_BIT (with
the exception of i1), to reduce one use of dependence on LLVM types. Would still
need to check it's an integer type though.

Or we can wait and stick with this for now.

[Karl, 2014/09/08 20:41:39]

Since we already depend of LLVM typesfor the types block and function address
signatures, I will leave it in for the moment.

+      APInt Value(IType->getBitWidth(),
+                  NaClDecodeSignRotatedValue(Values[0]));
+      Ice::Constant *C = getContext()->getConstantInt(
+          NextConstantType, Value.getSExtValue());
+      FuncParser->setNextConstantID(C);
+      return;
+    }
+    std::string Buffer;
+    raw_string_ostream StrBuf(Buffer);
+    StrBuf << "constant block integer record for non-integer type "
+           << NextConstantType;
+    Error(StrBuf.str());
+    return;
+  }
+  case naclbitc::CST_CODE_FLOAT: {
+    // FLOAT: [fpval]
+    if (!isValidRecordSize(1, "constants block float")) return;
+    if (!isValidNextConstantType()) return;
+    switch (NextConstantType) {
+    case Ice::IceType_f32: {
+      APFloat Value(APFloat::IEEEsingle,
+                    APInt(32, static_cast<uint32_t>(Values[0])));
+      FuncParser->setNextConstantID(
+          getContext()->getConstantFloat(Value.convertToFloat()));
+      return;
+    }
+    case Ice::IceType_f64: {
+      APFloat Value(APFloat::IEEEdouble, APInt(64, Values[0]));
+      FuncParser->setNextConstantID(
+          getContext()->getConstantDouble(Value.convertToDouble()));
+      return;
+    }
+    default: {
+      std::string Buffer;
+      raw_string_ostream StrBuf(Buffer);
+      StrBuf << "constant block float record for non-floating type "
+             << NextConstantType;
+      Error(StrBuf.str());
+      return;
+    }
+    }
+  }
+  default:
+    // Generate error message!
+    BlockParserBaseClass::ProcessRecord();
+    return;
+  }
+}
+
+bool FunctionParser::ParseBlock(unsigned BlockID) {
+  switch (BlockID) {
+  case naclbitc::CONSTANTS_BLOCK_ID: {
+    ConstantsParser Parser(BlockID, this);
+    return Parser.ParseThisBlock();
+  }
+  default:
+    return BlockParserBaseClass::ParseBlock(BlockID);
+  }
+}
+
 /// Parses the module block in the bitcode file.
 class ModuleParser : public BlockParserBaseClass {
 public:
   ModuleParser(unsigned BlockID, TopLevelParser *Context)
       : BlockParserBaseClass(BlockID, Context) {}
 
   virtual ~ModuleParser() LLVM_OVERRIDE {}
 
 protected:
   virtual bool ParseBlock(unsigned BlockID) LLVM_OVERRIDE;
@@ skipping 145 matching lines @@
   if (TopLevelBlocks != 1) {
     errs() << IRFilename
            << ": Contains more than one module. Found: " << TopLevelBlocks
            << "\n";
     ErrorStatus = true;
   }
   return;
 }
 
 } // end of namespace Ice