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

95 lines
4.7 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.
*/
/// \file override.hh
/// \brief A system for sending override commands to the decompiler
#ifndef __OVERRIDE_HH__
#define __OVERRIDE_HH__
#include "database.hh"
namespace ghidra {
class FuncCallSpecs; // Forward declaration
extern ElementId ELEM_DEADCODEDELAY; ///< Marshaling element \<deadcodedelay>
extern ElementId ELEM_FLOW; ///< Marshaling element \<flow>
extern ElementId ELEM_FORCEGOTO; ///< Marshaling element \<forcegoto>
extern ElementId ELEM_INDIRECTOVERRIDE; ///< Marshaling element \<indirectoverride>
extern ElementId ELEM_MULTISTAGEJUMP; ///< Marshaling element \<multistagejump>
extern ElementId ELEM_OVERRIDE; ///< Marshaling element \<override>
extern ElementId ELEM_PROTOOVERRIDE; ///< Marshaling element \<protooverride>
/// \brief A container of commands that override the decompiler's default behavior for a single function
///
/// Information about a particular function that can be overridden includes:
/// - sub-functions: How they are called and where they call to
/// - jumptables: Mark indirect jumps that need multistage analysis
/// - deadcode: Details about how dead code is eliminated
/// - data-flow: Override the interpretation of specific branch instructions
///
/// Commands exist independently of the main data-flow, control-flow, and symbol structures
/// and survive decompilation restart. A few analyses, mid transformation, insert a new command
/// to fix a problem that was discovered too late and then force a restart via Funcdata::setRestartPending()
///
/// The class accept new commands via the insert* methods. The decompiler applies them by
/// calling the apply* or get* methods.
class Override {
public:
/// \brief Enumeration of possible branch overrides
enum {
NONE = 0, ///< No override
BRANCH = 1, ///< Replace primary CALL or RETURN with suitable BRANCH operation
CALL = 2, ///< Replace primary BRANCH or RETURN with suitable CALL operation
CALL_RETURN = 3, ///< Replace primary BRANCH or RETURN with suitable CALL/RETURN operation
RETURN = 4 ///< Replace primary BRANCH or CALL with a suitable RETURN operation
};
private:
map<Address,Address> forcegoto; ///< Force goto on jump at \b targetpc to \b destpc
vector<int4> deadcodedelay; ///< Delay count indexed by address space
map<Address,Address> indirectover; ///< Override indirect at \b call-point into direct to \b addr
map<Address,FuncProto *> protoover; ///< Override prototype at \b call-point
vector<Address> multistagejump; ///< Addresses of indirect jumps that need multistage recovery
map<Address,uint4> flowoverride; ///< Override the CALL <-> BRANCH
void clear(void); ///< Clear the entire set of overrides
static string generateDeadcodeDelayMessage(int4 index,Architecture *glb);
public:
~Override(void) { clear(); } ///< Destructor
void insertForceGoto(const Address &targetpc,const Address &destpc);
void insertDeadcodeDelay(AddrSpace *spc,int4 delay);
bool hasDeadcodeDelay(AddrSpace *spc) const;
void insertIndirectOverride(const Address &callpoint,const Address &directcall);
void insertProtoOverride(const Address &callpoint,FuncProto *p);
void insertMultistageJump(const Address &addr);
void insertFlowOverride(const Address &addr,uint4 type);
void applyPrototype(Funcdata &data,FuncCallSpecs &fspecs) const;
void applyIndirect(Funcdata &data,FuncCallSpecs &fspecs) const;
bool queryMultistageJumptable(const Address &addr) const;
void applyDeadCodeDelay(Funcdata &data) const;
void applyForceGoto(Funcdata &data) const;
bool hasFlowOverride(void) const { return (!flowoverride.empty()); } ///< Are there any flow overrides
uint4 getFlowOverride(const Address &addr) const;
void printRaw(ostream &s,Architecture *glb) const;
void generateOverrideMessages(vector<string> &messagelist,Architecture *glb) const;
void encode(Encoder &encoder,Architecture *glb) const;
void decode(Decoder &decoder,Architecture *glb);
static string typeToString(uint4 tp); ///< Convert a flow override type to a string
static uint4 stringToType(const string &nm); ///< Convert a string to a flow override type
};
} // End namespace ghidra
#endif