cctools/include/llvm-c/Disassembler.h

   1 /*===-- llvm-c/Disassembler.h - Disassembler Public C Interface ---*- C -*-===*\
   2 |*                                                                            *|
   3 |*                     The LLVM Compiler Infrastructure                       *|
   4 |*                                                                            *|
   5 |* This file is distributed under the University of Illinois Open Source      *|
   6 |* License. See LICENSE.TXT for details.                                      *|
   7 |*                                                                            *|
   8 |*===----------------------------------------------------------------------===*|
   9 |*                                                                            *|
  10 |* This header provides public interface to a disassembler library.           *|
  11 |* LLVM provides an implementation of this interface.                         *|
  12 |*                                                                            *|
  13 \*===----------------------------------------------------------------------===*/
  14
  15 #ifndef LLVM_C_DISASSEMBLER_H
  16 #define LLVM_C_DISASSEMBLER_H  1
  17
  18 #include <stddef.h>
  19
  20 /**
  21  * An opaque reference to a disassembler context.
  22  */
  23 typedef void *LLVMDisasmContextRef;
  24
  25 /**
  26  * The type for the operand information call back function.  This is called to
  27  * get the symbolic information for an operand of an instruction.  Typically
  28  * this is from the relocation information, symbol table, etc.  That block of
  29  * information is saved when the disassembler context is created and passed to
  30  * the call back in the DisInfo parameter.  The instruction containing operand
  31  * is at the PC parameter.  For some instruction sets, there can be more than
  32  * one operand with symbolic information.  To determine the symbolic operand
  33  * infomation for each operand, the bytes for the specific operand in the
  34  * instruction are specified by the Offset parameter and its byte widith is the
  35  * size parameter.  For instructions sets with fixed widths and one symbolic
  36  * operand per instruction, the Offset parameter will be zero and Size parameter
  37  * will be the instruction width.  The information is returned in TagBuf and is
  38  * Triple specific with its specific information defined by the value of
  39  * TagType for that Triple.  If symbolic information is returned the function
  40  * returns 1 else it returns 0.
  41  */
  42 typedef int (*LLVMOpInfoCallback)(void *DisInfo,
  43                                   uint64_t Pc,
  44                                   uint64_t Offset,
  45                                   uint64_t Size,
  46                                   int TagType,
  47                                   void *TagBuf);
  48
  49 /**
  50  * The initial support in LLVM MC for the most general form of a relocatable
  51  * expression is "AddSymbol - SubtractSymbol + Offset".  For some Darwin targets
  52  * this full form is encoded in the relocation information so that AddSymbol and
  53  * SubtractSymbol can be link edited independent of each other.  Many other
  54  * platforms only allow a relocatable expression of the form AddSymbol + Offset
  55  * to be encoded.
  56  *
  57  * The LLVMOpInfoCallback() for the TagType value of 1 uses the struct
  58  * LLVMOpInfo1.  The value of the relocatable expression for the operand,
  59  * including any PC adjustment, is passed in to the call back in the Value
  60  * field.  The symbolic information about the operand is returned using all
  61  * the fields of the structure with the Offset of the relocatable expression
  62  * returned in the Value field.  It is possible that some symbols in the
  63  * relocatable expression were assembly temporary symbols, for example
  64  * "Ldata - LpicBase + constant", and only the Values of the symbols without
  65  * symbol names are present in the relocation information.  The VariantKind
  66  * type is one of the Target specific #defines below and is used to print
  67  * operands like "_foo@GOT", ":lower16:_foo", etc.
  68  */
  69 struct LLVMOpInfoSymbol1 {
  70   uint64_t Present; /* 1 if this symbol is present */
  71   const char *Name; /* symbol name if not NULL */
  72   uint64_t Value;   /* symbol value if name is NULL */
  73 };
  74 struct LLVMOpInfo1 {
  75   struct LLVMOpInfoSymbol1 AddSymbol;
  76   struct LLVMOpInfoSymbol1 SubtractSymbol;
  77   uint64_t Value;
  78   uint64_t VariantKind;
  79 };
  80
  81 /**
  82  * The operand VariantKinds for symbolic disassembly.
  83  */
  84 #define LLVMDisassembler_VariantKind_None 0 /* all targets */
  85
  86 /**
  87  * The ARM target VariantKinds.
  88  */
  89 #define LLVMDisassembler_VariantKind_ARM_HI16 1 /* :upper16: */
  90 #define LLVMDisassembler_VariantKind_ARM_LO16 2 /* :lower16: */
  91
  92 /**
  93  * The type for the symbol lookup function.  This may be called by the
  94  * disassembler for such things like adding a comment for a PC plus a constant
  95  * offset load instruction to use a symbol name instead of a load address value.
  96  * It is passed the block information is saved when the disassembler context is
  97  * created and a value of a symbol to look up.  If no symbol is found NULL is
  98  * to be returned.
  99  */
 100 typedef const char *(*LLVMSymbolLookupCallback)(void *DisInfo,
 101                                                 uint64_t SymbolValue);
 102
 103 #ifdef __cplusplus
 104 extern "C" {
 105 #endif /* !defined(__cplusplus) */
 106
 107 /**
 108  * Create a disassembler for the TripleName.  Symbolic disassembly is supported
 109  * by passing a block of information in the DisInfo parameter and specifing the
 110  * TagType and call back functions as described above.  These can all be passed
 111  * as NULL.  If successfull this returns a disassembler context if not it
 112  * returns NULL.
 113  */
 114 extern LLVMDisasmContextRef
 115 LLVMCreateDisasm(const char *TripleName,
 116                  void *DisInfo,
 117                  int TagType,
 118                  LLVMOpInfoCallback GetOpInfo,
 119                  LLVMSymbolLookupCallback SymbolLookUp);
 120
 121 /**
 122  * Dispose of a disassembler context.
 123  */
 124 extern void
 125 LLVMDisasmDispose(LLVMDisasmContextRef DC);
 126
 127 /**
 128  * Disassmble a single instruction using the disassembler context specified in
 129  * the parameter DC.  The bytes of the instuction are specified in the parameter
 130  * Bytes, and contains at least BytesSize number of bytes.  The instruction is
 131  * at the address specified by the PC parameter.  If a valid instruction can be
 132  * disassembled its string is returned indirectly in OutString which whos size
 133  * is specified in the parameter OutStringSize.  This function returns the
 134  * number of bytes in the instruction or zero if there was no valid instruction.
 135  */
 136 extern size_t
 137 LLVMDisasmInstruction(LLVMDisasmContextRef DC,
 138                       uint8_t *Bytes,
 139                       uint64_t BytesSize,
 140                       uint64_t Pc,
 141                       char *OutString,
 142                       size_t OutStringSize);
 143
 144 #ifdef __cplusplus
 145 }
 146 #endif /* !defined(__cplusplus) */
 147
 148 #endif /* !defined(LLVM_C_DISASSEMBLER_H) */