ghidra/Ghidra/Features/Decompiler/src/decompile/cpp/context.hh

204 lines
9.4 KiB
C++

/* ###
* IP: GHIDRA
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __CONTEXT_HH__
#define __CONTEXT_HH__
#include "globalcontext.hh"
#include "opcodes.hh"
namespace ghidra {
class Token { // A multiple-byte sized chunk of pattern in a bitstream
string name;
int4 size; // Number of bytes in token;
int4 index; // Index of this token, for resolving offsets
bool bigendian;
public:
Token(const string &nm,int4 sz,bool be,int4 ind) : name(nm) { size = sz; bigendian=be; index = ind; }
int4 getSize(void) const { return size; }
bool isBigEndian(void) const { return bigendian; }
int4 getIndex(void) const { return index; }
const string &getName(void) const { return name; }
};
struct FixedHandle { // A handle that is fully resolved
AddrSpace *space;
uint4 size;
AddrSpace *offset_space; // Either null or where dynamic offset is stored
uintb offset_offset; // Either static offset or ptr offset
uint4 offset_size; // Size of pointer
AddrSpace *temp_space; // Consistent temporary location for value
uintb temp_offset;
};
class Constructor;
struct ConstructState {
Constructor *ct;
FixedHandle hand;
vector<ConstructState *> resolve;
ConstructState *parent;
int4 length; // Length of this instantiation of the constructor
uint4 offset; // Absolute offset (from start of instruction)
};
class TripleSymbol;
struct ContextSet { // Instructions for setting a global context value
TripleSymbol *sym; // Resolves to address where setting takes effect
ConstructState *point; // Point at which context set was made
int4 num; // Number of context word affected
uintm mask; // Bits within word affected
uintm value; // New setting for bits
bool flow; // Does the new context flow from its set point
};
class ParserWalker; // Forward declaration
class ParserWalkerChange;
class Translate;
class ParserContext {
friend class ParserWalker;
friend class ParserWalkerChange;
public:
enum { // Possible states of the ParserContext
uninitialized = 0, // Instruction has not been parsed at all
disassembly = 1, // Instruction is parsed in preparation for disassembly
pcode = 2 // Instruction is parsed in preparation for generating p-code
};
private:
Translate *translate; // Instruction parser
int4 parsestate;
AddrSpace *const_space;
uint1 buf[16]; // Buffer of bytes in the instruction stream
uintm *context; // Pointer to local context
int4 contextsize; // Number of entries in context array
ContextCache *contcache; // Interface for getting/setting context
vector<ContextSet> contextcommit;
Address addr; // Address of start of instruction
Address naddr; // Address of next instruction
mutable Address n2addr; // Address of instruction after the next
Address calladdr; // For injections, this is the address of the call being overridden
vector<ConstructState> state; // Current resolved instruction
ConstructState *base_state;
int4 alloc; // Number of ConstructState's allocated
int4 delayslot; // delayslot depth
public:
ParserContext(ContextCache *ccache,Translate *trans);
~ParserContext(void) { if (context != (uintm *)0) delete [] context; }
uint1 *getBuffer(void) { return buf; }
void initialize(int4 maxstate,int4 maxparam,AddrSpace *spc);
int4 getParserState(void) const { return parsestate; }
void setParserState(int4 st) { parsestate = st; }
void deallocateState(ParserWalkerChange &walker);
void allocateOperand(int4 i,ParserWalkerChange &walker);
void setAddr(const Address &ad) { addr = ad; n2addr = Address(); }
void setNaddr(const Address &ad) { naddr = ad; }
void setCalladdr(const Address &ad) { calladdr = ad; }
void addCommit(TripleSymbol *sym,int4 num,uintm mask,bool flow,ConstructState *point);
void clearCommits(void) { contextcommit.clear(); }
void applyCommits(void);
const Address &getAddr(void) const { return addr; }
const Address &getNaddr(void) const { return naddr; }
const Address &getN2addr(void) const;
const Address &getDestAddr(void) const { return calladdr; }
const Address &getRefAddr(void) const { return calladdr; }
AddrSpace *getCurSpace(void) const { return addr.getSpace(); }
AddrSpace *getConstSpace(void) const { return const_space; }
uintm getInstructionBytes(int4 byteoff,int4 numbytes,uint4 off) const;
uintm getContextBytes(int4 byteoff,int4 numbytes) const;
uintm getInstructionBits(int4 startbit,int4 size,uint4 off) const;
uintm getContextBits(int4 startbit,int4 size) const;
void setContextWord(int4 i,uintm val,uintm mask) { context[i] = (context[i]&(~mask))|(mask&val); }
void loadContext(void) { contcache->getContext(addr,context); }
int4 getLength(void) const { return base_state->length; }
void setDelaySlot(int4 val) { delayslot = val; }
int4 getDelaySlot(void) const { return delayslot; }
};
class ParserWalker { // A class for walking the ParserContext
const ParserContext *const_context;
const ParserContext *cross_context;
protected:
ConstructState *point; // The current node being visited
int4 depth; // Depth of the current node
int4 breadcrumb[32]; // Path of operands from root
public:
ParserWalker(const ParserContext *c) { const_context = c; cross_context = (const ParserContext *)0; }
ParserWalker(const ParserContext *c,const ParserContext *cross) { const_context = c; cross_context = cross; }
const ParserContext *getParserContext(void) const { return const_context; }
void baseState(void) { point = const_context->base_state; depth=0; breadcrumb[0] = 0; }
void setOutOfBandState(Constructor *ct,int4 index,ConstructState *tempstate,const ParserWalker &otherwalker);
bool isState(void) const { return (point != (ConstructState *)0); }
void pushOperand(int4 i) { breadcrumb[depth++] = i+1; point = point->resolve[i]; breadcrumb[depth] = 0; }
void popOperand(void) { point = point->parent; depth-= 1; }
uint4 getOffset(int4 i) const { if (i<0) return point->offset;
ConstructState *op=point->resolve[i]; return op->offset + op->length; }
Constructor *getConstructor(void) const { return point->ct; }
int4 getOperand(void) const { return breadcrumb[depth]; }
FixedHandle &getParentHandle(void) { return point->hand; }
const FixedHandle &getFixedHandle(int4 i) const { return point->resolve[i]->hand; }
AddrSpace *getCurSpace(void) const { return const_context->getCurSpace(); }
AddrSpace *getConstSpace(void) const { return const_context->getConstSpace(); }
const Address &getAddr(void) const { if (cross_context != (const ParserContext *)0) { return cross_context->getAddr(); } return const_context->getAddr(); }
const Address &getNaddr(void) const { if (cross_context != (const ParserContext *)0) { return cross_context->getNaddr();} return const_context->getNaddr(); }
const Address &getN2addr(void) const { if (cross_context != (const ParserContext *)0) { return cross_context->getN2addr();} return const_context->getN2addr(); }
const Address &getRefAddr(void) const { if (cross_context != (const ParserContext *)0) { return cross_context->getRefAddr();} return const_context->getRefAddr(); }
const Address &getDestAddr(void) const { if (cross_context != (const ParserContext *)0) { return cross_context->getDestAddr();} return const_context->getDestAddr(); }
int4 getLength(void) const { return const_context->getLength(); }
uintm getInstructionBytes(int4 byteoff,int4 numbytes) const {
return const_context->getInstructionBytes(byteoff,numbytes,point->offset); }
uintm getContextBytes(int4 byteoff,int4 numbytes) const {
return const_context->getContextBytes(byteoff,numbytes); }
uintm getInstructionBits(int4 startbit,int4 size) const {
return const_context->getInstructionBits(startbit,size,point->offset); }
uintm getContextBits(int4 startbit,int4 size) const {
return const_context->getContextBits(startbit,size); }
};
class ParserWalkerChange : public ParserWalker { // Extension to walker that allows for on the fly modifications to tree
friend class ParserContext;
ParserContext *context;
public:
ParserWalkerChange(ParserContext *c) : ParserWalker(c) { context = c; }
ParserContext *getParserContext(void) { return context; }
ConstructState *getPoint(void) { return point; }
void setOffset(uint4 off) { point->offset = off; }
void setConstructor(Constructor *c) { point->ct = c; }
void setCurrentLength(int4 len) { point->length = len; }
void calcCurrentLength(int4 length,int4 numopers);
};
struct SleighError : public LowlevelError {
SleighError(const string &s) : LowlevelError(s) {}
};
inline void ParserContext::deallocateState(ParserWalkerChange &walker) {
alloc = 1;
walker.context=this;
walker.baseState();
}
inline void ParserContext::allocateOperand(int4 i,ParserWalkerChange &walker) {
ConstructState *opstate = &state[alloc++];
opstate->parent = walker.point;
opstate->ct = (Constructor *)0;
walker.point->resolve[i] = opstate;
walker.breadcrumb[walker.depth++] += 1;
walker.point = opstate;
walker.breadcrumb[walker.depth] = 0;
}
} // End namespace ghidra
#endif