X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FMC%2FMCDisassembler.h;h=53a9ce0a3648f9b987c1b469be8fc1f7c2c3d218;hb=f9e008bf673a8eeb04766bfc99f51068608809d2;hp=0fdb51b11bf47b307706d36740a1252917f99781;hpb=cdc06fa3c7d68b92f56a5a9c537ac159aefc6323;p=oota-llvm.git

diff --git a/include/llvm/MC/MCDisassembler.h b/include/llvm/MC/MCDisassembler.h
index 0fdb51b11bf..53a9ce0a364 100644
--- a/include/llvm/MC/MCDisassembler.h
+++ b/include/llvm/MC/MCDisassembler.h
@@ -10,27 +10,60 @@
 #define MCDISASSEMBLER_H
 
 #include "llvm/Support/DataTypes.h"
+#include "llvm-c/Disassembler.h"
 
 namespace llvm {
-  
+
 class MCInst;
+class MCSubtargetInfo;
 class MemoryObject;
 class raw_ostream;
-  
+class MCContext;
+
 struct EDInstInfo;
 
 /// MCDisassembler - Superclass for all disassemblers.  Consumes a memory region
 ///   and provides an array of assembly instructions.
 class MCDisassembler {
 public:
+  /// Ternary decode status. Most backends will just use Fail and
+  /// Success, however some have a concept of an instruction with
+  /// understandable semantics but which is architecturally
+  /// incorrect. An example of this is ARM UNPREDICTABLE instructions
+  /// which are disassemblable but cause undefined behaviour.
+  ///
+  /// Because it makes sense to disassemble these instructions, there
+  /// is a "soft fail" failure mode that indicates the MCInst& is
+  /// valid but architecturally incorrect.
+  ///
+  /// The enum numbers are deliberately chosen such that reduction
+  /// from Success->SoftFail ->Fail can be done with a simple
+  /// bitwise-AND:
+  ///
+  ///   LEFT & TOP =  | Success       Unpredictable   Fail
+  ///   --------------+-----------------------------------
+  ///   Success       | Success       Unpredictable   Fail
+  ///   Unpredictable | Unpredictable Unpredictable   Fail
+  ///   Fail          | Fail          Fail            Fail
+  ///
+  /// An easy way of encoding this is as 0b11, 0b01, 0b00 for
+  /// Success, SoftFail, Fail respectively.
+  enum DecodeStatus {
+    Fail = 0,
+    SoftFail = 1,
+    Success = 3
+  };
+
   /// Constructor     - Performs initial setup for the disassembler.
-  MCDisassembler() {}
-  
+  MCDisassembler(const MCSubtargetInfo &STI) : GetOpInfo(0), SymbolLookUp(0),
+                                               DisInfo(0), Ctx(0),
+                                               STI(STI), CommentStream(0) {}
+
   virtual ~MCDisassembler();
-  
+
   /// getInstruction  - Returns the disassembly of a single instruction.
   ///
-  /// @param instr    - An MCInst to populate with the contents of the 
+  /// @param instr    - An MCInst to populate with the contents of the
   ///                   instruction.
   /// @param size     - A value to populate with the size of the instruction, or
   ///                   the number of bytes consumed while attempting to decode
@@ -39,12 +72,17 @@ public:
   /// @param address  - The address, in the memory space of region, of the first
   ///                   byte of the instruction.
   /// @param vStream  - The stream to print warnings and diagnostic messages on.
-  /// @return         - True if the instruction is valid; false otherwise.
-  virtual bool          getInstruction(MCInst& instr,
+  /// @param cStream  - The stream to print comments and annotations on.
+  /// @return         - MCDisassembler::Success if the instruction is valid,
+  ///                   MCDisassembler::SoftFail if the instruction was
+  ///                                            disassemblable but invalid,
+  ///                   MCDisassembler::Fail if the instruction was invalid.
+  virtual DecodeStatus  getInstruction(MCInst& instr,
                                        uint64_t& size,
                                        const MemoryObject &region,
                                        uint64_t address,
-                                       raw_ostream &vStream) const = 0;
+                                       raw_ostream &vStream,
+                                       raw_ostream &cStream) const = 0;
 
   /// getEDInfo - Returns the enhanced instruction information corresponding to
   ///   the disassembler.
@@ -52,7 +90,45 @@ public:
   /// @return         - An array of instruction information, with one entry for
   ///                   each MCInst opcode this disassembler returns.
   ///                   NULL if there is no info for this target.
-  virtual EDInstInfo   *getEDInfo() const { return (EDInstInfo*)0; }
+  virtual const EDInstInfo   *getEDInfo() const { return (EDInstInfo*)0; }
+
+private:
+  //
+  // Hooks for symbolic disassembly via the public 'C' interface.
+  //
+  // The function to get the symbolic information for operands.
+  LLVMOpInfoCallback GetOpInfo;
+  // The function to lookup a symbol name.
+  LLVMSymbolLookupCallback SymbolLookUp;
+  // The pointer to the block of symbolic information for above call back.
+  void *DisInfo;
+  // The assembly context for creating symbols and MCExprs in place of
+  // immediate operands when there is symbolic information.
+  MCContext *Ctx;
+protected:
+  // Subtarget information, for instruction decoding predicates if required.
+  const MCSubtargetInfo &STI;
+
+public:
+  void setupForSymbolicDisassembly(LLVMOpInfoCallback getOpInfo,
+                                   LLVMSymbolLookupCallback symbolLookUp,
+                                   void *disInfo,
+                                   MCContext *ctx) {
+    GetOpInfo = getOpInfo;
+    SymbolLookUp = symbolLookUp;
+    DisInfo = disInfo;
+    Ctx = ctx;
+  }
+  LLVMOpInfoCallback getLLVMOpInfoCallback() const { return GetOpInfo; }
+  LLVMSymbolLookupCallback getLLVMSymbolLookupCallback() const {
+    return SymbolLookUp;
+  }
+  void *getDisInfoBlock() const { return DisInfo; }
+  MCContext *getMCContext() const { return Ctx; }
+
+  // Marked mutable because we cache it inside the disassembler, rather than
+  // having to pass it around as an argument through all the autogenerated code.
+  mutable raw_ostream *CommentStream;
 };
 
 } // namespace llvm