llvm-6502/include/llvm-c/Disassembler.h
Kevin Enderby 6f45b1f0d6 Add to the disassembler C API output reference types for
Objective-C data structures.

This is allows tools such as darwin's otool(1) that uses the
LLVM disassembler take a pointer value being loaded by
an instruction and add a comment to what it is being referenced
to make following disassembly of Objective-C programs
more readable.

For example disassembling the Mac OS X TextEdit app one
will see comments like the following:

movq    0x20684(%rip), %rsi ## Objc selector ref: standardUserDefaults
movq    0x21985(%rip), %rdi ## Objc class ref: _OBJC_CLASS_$_NSUserDefaults
movq    0x1d156(%rip), %r14 ## Objc message: +[NSUserDefaults standardUserDefaults]
leaq    0x23615(%rip), %rdx ## Objc cfstring ref: @"SelectLinePanel"
callq   0x10001386c ## Objc message: -[[%rdi super] initWithWindowNibName:]

These diffs also include putting quotes around C strings
in literal pools and uses "symbol address" in the comment
when adding a symbol name to the comment to tell these
types of references apart:

leaq	0x4f(%rip), %rax ## literal pool for: "Hello world"
movq    0x1c3ea(%rip), %rax ## literal pool symbol address: ___stack_chk_guard

Of course the easy changes are in the LLVM disassembler and
the hard work is up to the implementer of the SymbolLookUp()
call back.

rdar://10602439


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193833 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-01 00:00:07 +00:00

217 lines
9.8 KiB
C

/*===-- llvm-c/Disassembler.h - Disassembler Public C Interface ---*- C -*-===*\
|* *|
|* The LLVM Compiler Infrastructure *|
|* *|
|* This file is distributed under the University of Illinois Open Source *|
|* License. See LICENSE.TXT for details. *|
|* *|
|*===----------------------------------------------------------------------===*|
|* *|
|* This header provides a public interface to a disassembler library. *|
|* LLVM provides an implementation of this interface. *|
|* *|
\*===----------------------------------------------------------------------===*/
#ifndef LLVM_C_DISASSEMBLER_H
#define LLVM_C_DISASSEMBLER_H
#include "llvm/Support/DataTypes.h"
#include <stddef.h>
/**
* @defgroup LLVMCDisassembler Disassembler
* @ingroup LLVMC
*
* @{
*/
/**
* An opaque reference to a disassembler context.
*/
typedef void *LLVMDisasmContextRef;
/**
* The type for the operand information call back function. This is called to
* get the symbolic information for an operand of an instruction. Typically
* this is from the relocation information, symbol table, etc. That block of
* information is saved when the disassembler context is created and passed to
* the call back in the DisInfo parameter. The instruction containing operand
* is at the PC parameter. For some instruction sets, there can be more than
* one operand with symbolic information. To determine the symbolic operand
* information for each operand, the bytes for the specific operand in the
* instruction are specified by the Offset parameter and its byte widith is the
* size parameter. For instructions sets with fixed widths and one symbolic
* operand per instruction, the Offset parameter will be zero and Size parameter
* will be the instruction width. The information is returned in TagBuf and is
* Triple specific with its specific information defined by the value of
* TagType for that Triple. If symbolic information is returned the function
* returns 1, otherwise it returns 0.
*/
typedef int (*LLVMOpInfoCallback)(void *DisInfo, uint64_t PC,
uint64_t Offset, uint64_t Size,
int TagType, void *TagBuf);
/**
* The initial support in LLVM MC for the most general form of a relocatable
* expression is "AddSymbol - SubtractSymbol + Offset". For some Darwin targets
* this full form is encoded in the relocation information so that AddSymbol and
* SubtractSymbol can be link edited independent of each other. Many other
* platforms only allow a relocatable expression of the form AddSymbol + Offset
* to be encoded.
*
* The LLVMOpInfoCallback() for the TagType value of 1 uses the struct
* LLVMOpInfo1. The value of the relocatable expression for the operand,
* including any PC adjustment, is passed in to the call back in the Value
* field. The symbolic information about the operand is returned using all
* the fields of the structure with the Offset of the relocatable expression
* returned in the Value field. It is possible that some symbols in the
* relocatable expression were assembly temporary symbols, for example
* "Ldata - LpicBase + constant", and only the Values of the symbols without
* symbol names are present in the relocation information. The VariantKind
* type is one of the Target specific #defines below and is used to print
* operands like "_foo@GOT", ":lower16:_foo", etc.
*/
struct LLVMOpInfoSymbol1 {
uint64_t Present; /* 1 if this symbol is present */
const char *Name; /* symbol name if not NULL */
uint64_t Value; /* symbol value if name is NULL */
};
struct LLVMOpInfo1 {
struct LLVMOpInfoSymbol1 AddSymbol;
struct LLVMOpInfoSymbol1 SubtractSymbol;
uint64_t Value;
uint64_t VariantKind;
};
/**
* The operand VariantKinds for symbolic disassembly.
*/
#define LLVMDisassembler_VariantKind_None 0 /* all targets */
/**
* The ARM target VariantKinds.
*/
#define LLVMDisassembler_VariantKind_ARM_HI16 1 /* :upper16: */
#define LLVMDisassembler_VariantKind_ARM_LO16 2 /* :lower16: */
/**
* The type for the symbol lookup function. This may be called by the
* disassembler for things like adding a comment for a PC plus a constant
* offset load instruction to use a symbol name instead of a load address value.
* It is passed the block information is saved when the disassembler context is
* created and the ReferenceValue to look up as a symbol. If no symbol is found
* for the ReferenceValue NULL is returned. The ReferenceType of the
* instruction is passed indirectly as is the PC of the instruction in
* ReferencePC. If the output reference can be determined its type is returned
* indirectly in ReferenceType along with ReferenceName if any, or that is set
* to NULL.
*/
typedef const char *(*LLVMSymbolLookupCallback)(void *DisInfo,
uint64_t ReferenceValue,
uint64_t *ReferenceType,
uint64_t ReferencePC,
const char **ReferenceName);
/**
* The reference types on input and output.
*/
/* No input reference type or no output reference type. */
#define LLVMDisassembler_ReferenceType_InOut_None 0
/* The input reference is from a branch instruction. */
#define LLVMDisassembler_ReferenceType_In_Branch 1
/* The input reference is from a PC relative load instruction. */
#define LLVMDisassembler_ReferenceType_In_PCrel_Load 2
/* The output reference is to as symbol stub. */
#define LLVMDisassembler_ReferenceType_Out_SymbolStub 1
/* The output reference is to a symbol address in a literal pool. */
#define LLVMDisassembler_ReferenceType_Out_LitPool_SymAddr 2
/* The output reference is to a cstring address in a literal pool. */
#define LLVMDisassembler_ReferenceType_Out_LitPool_CstrAddr 3
/* The output reference is to a Objective-C CoreFoundation string. */
#define LLVMDisassembler_ReferenceType_Out_Objc_CFString_Ref 4
/* The output reference is to a Objective-C message. */
#define LLVMDisassembler_ReferenceType_Out_Objc_Message 5
/* The output reference is to a Objective-C message ref. */
#define LLVMDisassembler_ReferenceType_Out_Objc_Message_Ref 6
/* The output reference is to a Objective-C selector ref. */
#define LLVMDisassembler_ReferenceType_Out_Objc_Selector_Ref 7
/* The output reference is to a Objective-C class ref. */
#define LLVMDisassembler_ReferenceType_Out_Objc_Class_Ref 8
#ifdef __cplusplus
extern "C" {
#endif /* !defined(__cplusplus) */
/**
* Create a disassembler for the TripleName. Symbolic disassembly is supported
* by passing a block of information in the DisInfo parameter and specifying the
* TagType and callback functions as described above. These can all be passed
* as NULL. If successful, this returns a disassembler context. If not, it
* returns NULL. This function is equivalent to calling LLVMCreateDisasmCPU()
* with an empty CPU name.
*/
LLVMDisasmContextRef LLVMCreateDisasm(const char *TripleName, void *DisInfo,
int TagType, LLVMOpInfoCallback GetOpInfo,
LLVMSymbolLookupCallback SymbolLookUp);
/**
* Create a disassembler for the TripleName and a specific CPU. Symbolic
* disassembly is supported by passing a block of information in the DisInfo
* parameter and specifying the TagType and callback functions as described
* above. These can all be passed * as NULL. If successful, this returns a
* disassembler context. If not, it returns NULL.
*/
LLVMDisasmContextRef LLVMCreateDisasmCPU(const char *Triple, const char *CPU,
void *DisInfo, int TagType,
LLVMOpInfoCallback GetOpInfo,
LLVMSymbolLookupCallback SymbolLookUp);
/**
* Set the disassembler's options. Returns 1 if it can set the Options and 0
* otherwise.
*/
int LLVMSetDisasmOptions(LLVMDisasmContextRef DC, uint64_t Options);
/* The option to produce marked up assembly. */
#define LLVMDisassembler_Option_UseMarkup 1
/* The option to print immediates as hex. */
#define LLVMDisassembler_Option_PrintImmHex 2
/* The option use the other assembler printer variant */
#define LLVMDisassembler_Option_AsmPrinterVariant 4
/* The option to set comment on instructions */
#define LLVMDisassembler_Option_SetInstrComments 8
/* The option to print latency information alongside instructions */
#define LLVMDisassembler_Option_PrintLatency 16
/**
* Dispose of a disassembler context.
*/
void LLVMDisasmDispose(LLVMDisasmContextRef DC);
/**
* Disassemble a single instruction using the disassembler context specified in
* the parameter DC. The bytes of the instruction are specified in the
* parameter Bytes, and contains at least BytesSize number of bytes. The
* instruction is at the address specified by the PC parameter. If a valid
* instruction can be disassembled, its string is returned indirectly in
* OutString whose size is specified in the parameter OutStringSize. This
* function returns the number of bytes in the instruction or zero if there was
* no valid instruction.
*/
size_t LLVMDisasmInstruction(LLVMDisasmContextRef DC, uint8_t *Bytes,
uint64_t BytesSize, uint64_t PC,
char *OutString, size_t OutStringSize);
/**
* @}
*/
#ifdef __cplusplus
}
#endif /* !defined(__cplusplus) */
#endif /* !defined(LLVM_C_DISASSEMBLER_H) */