Initial skeleton of Subzero.

IceCfg.h

+// -*- Mode: c++ -*-
+/* Copyright 2014 The Native Client Authors. All rights reserved.

[Mark Seaborn, 2014/03/20 00:09:47]

Can you use the LLVM licence and boilerplate style, please?

[Jim Stichnoth, 2014/03/20 22:58:45]

Done.  (Waiting for a suitable LICENSE.TXT file from the Open Source team.)

+ * Use of this source code is governed by a BSD-style license that can
+ * be found in the LICENSE file.
+ */
+

[Mark Seaborn, 2014/03/20 00:09:47]

Can you put these files in a src/ or lib/ directory to match LLVM and make the
source tree more manageable?

Maybe headers should go in an include/ dir, too?

[Jim Stichnoth, 2014/03/20 22:58:45]

Done.  I moved *.{h,cpp} into the src/ subdirectory.  I changed the Makefile to
put .o files into the build/ subdirectory.

I vastly prefer keeping src and include files in the same directory, compared to
the way LLVM separates them.  Given the relatively small number of Subzero
source files, and the LLVM precedent of mixing src and include files in some
places (e.g. under Target/), I would keep them together.

+#ifndef _IceCfg_h

[Mark Seaborn, 2014/03/20 00:09:47]

Can you use the LLVM style?  i.e. ICECFG_H

[Jim Stichnoth, 2014/03/20 22:58:45]

Done.

+#define _IceCfg_h
+
+#include "IceDefs.h"
+#include "IceTypes.h"
+
+#include "llvm/Support/Allocator.h"
+
+class IceCfg {
+public:
+  IceCfg(void);

[Mark Seaborn, 2014/03/20 00:09:47]

Can you use "()" (C++ style) rather than "(void)" (C style)?

[Jim Stichnoth, 2014/03/20 22:58:45]

Done.

+  ~IceCfg();
+
+  // Manage the name and return type of the function being translated.
+  void setName(const IceString &FunctionName) { Name = FunctionName; }
+  IceString getName(void) const { return Name; }
+  void setReturnType(IceType ReturnType) { Type = ReturnType; }
+
+  // When emitting assembly, we allow a string to be prepended to
+  // names of translated functions.  This makes it easier to create an
+  // execution test against a reference translator like llc, with both
+  // translators using the same bitcode as input.
+  void setTestPrefix(const IceString &Prefix) { TestPrefix = Prefix; }
+  IceString getTestPrefix(void) const { return TestPrefix; }
+  IceString mangleName(const IceString &Name) const {
+    return getTestPrefix() + Name;
+  }
+
+  // Manage the "internal" attribute of the function.
+  void setInternal(bool Internal) { IsInternal = Internal; }
+  bool getInternal(void) const { return IsInternal; }
+
+  // Translation error flagging.  If support for some construct is
+  // known to be missing, instead of an assertion failure, setError()
+  // should be called and the error should be propagated back up.
+  // This way, we can gracefully fail to translate and let a fallback
+  // translator handle the function.
+  void setError(const IceString &Message);
+  bool hasError(void) const { return HasError; }
+  IceString getError(void) const { return ErrorMessage; }
+
+  // Manage nodes (a.k.a. basic blocks, IceCfgNodes).
+  void setEntryNode(IceCfgNode *EntryNode) { Entry = EntryNode; }
+  IceCfgNode *getEntryNode(void) const { return Entry; }
+  // Create a node and append it to the end of the linearized list.
+  IceCfgNode *makeNode(const IceString &Name = "");
+  uint32_t getNumNodes(void) const { return Nodes.size(); }
+  const IceNodeList &getNodes(void) const { return Nodes; }
+
+  // Manage instruction numbering.
+  int newInstNumber(void) { return NextInstNumber++; }
+
+  // Manage IceVariables.
+  IceVariable *makeVariable(IceType Type, const IceCfgNode *Node,
+                            const IceString &Name = "");
+  uint32_t getNumVariables(void) const { return Variables.size(); }
+  const IceVarList &getVariables(void) const { return Variables; }
+
+  // Manage arguments to the function.
+  void addArg(IceVariable *Arg);
+  const IceVarList &getArgs(void) const { return Args; }
+
+  // Manage IceConstants.
+  // getConstant*() functions are not const because they might add
+  // something to the constant pool.
+  IceConstant *getConstantInt(IceType Type, uint64_t ConstantInt64);
+  IceConstant *getConstantFloat(float Value);
+  IceConstant *getConstantDouble(double Value);
+  // Returns a symbolic constant.  Handle is currently unused but is
+  // reserved to hold something LLVM-specific to facilitate linking.
+  IceConstant *getConstantSym(IceType Type, const void *Handle, int64_t Offset,
+                              const IceString &Name = "",
+                              bool SuppressMangling = false);
+
+  void registerEdges(void);
+  void dump(void) const;
+
+  // Allocate an instruction of type T using the per-Cfg instruction allocator.
+  template <typename T> T *allocateInst() { return Allocator.Allocate<T>(); }
+
+  // Allocate an array of data of type T using the per-Cfg allocator.
+  template <typename T> T *allocateArrayOf(size_t NumElems) {
+    return Allocator.Allocate<T>(NumElems);
+  }
+
+  mutable IceOstream Str;
+
+private:
+  // TODO: for now, everything is allocated from the same allocator. In the
+  // future we may want to split this to several allocators, for example in
+  // order to use a "Recycler" to preserve memory. If we keep all allocation
+  // requests from the Cfg exposed via methods, we can always switch the
+  // implementation over at a later point.
+  llvm::BumpPtrAllocator Allocator;
+
+  IceString Name;       // function name
+  IceString TestPrefix; // prepended to all symbol names, for testing
+  IceType Type;         // return type
+  bool IsInternal;      // internal linkage
+  bool HasError;
+  IceString ErrorMessage;
+  IceCfgNode *Entry; // entry basic block
+  IceNodeList Nodes; // linearized node list; Entry should be first
+  int NextInstNumber;
+  IceVarList Variables;
+  IceVarList Args; // subset of Variables, in argument order
+  class IceConstantPool *ConstantPool;
+};
+
+#endif // _IceCfg_h