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

499 lines
26 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 modelrules.hh
/// \brief Definitions for rules governing mapping of data-type to address for prototype models
#ifndef __MODELRULES_HH__
#define __MODELRULES_HH__
#include "op.hh"
namespace ghidra {
class ParameterPieces;
class ParamListStandard;
class ParamEntry;
class ParamActive;
extern ElementId ELEM_DATATYPE; ///< Marshaling element \<datatype>
extern ElementId ELEM_CONSUME; ///< Marshaling element \<consume>
extern ElementId ELEM_CONSUME_EXTRA; ///< Marshaling element \<consume_extra>
extern ElementId ELEM_CONVERT_TO_PTR; ///< Marshaling element \<convert_to_ptr>
extern ElementId ELEM_GOTO_STACK; ///< Marshaling element \<goto_stack>
extern ElementId ELEM_JOIN; ///< Marshaling element \<join>
extern ElementId ELEM_DATATYPE_AT; ///< Marshaling element \<datatype_at>
extern ElementId ELEM_POSITION; ///< Marshaling element \<position>
extern ElementId ELEM_VARARGS; ///< Marshaling element \<varargs>
extern ElementId ELEM_HIDDEN_RETURN; ///< Marshaling element \<hidden_return>
extern ElementId ELEM_JOIN_PER_PRIMITIVE; ///< Marshaling element \<join_per_primitive>
extern ElementId ELEM_JOIN_DUAL_CLASS; ///< Marshaling element \<join_dual_class>
/// \brief Class for extracting primitive elements of a data-type
///
/// This recursively collects the formal \e primitive data-types of a composite data-type,
/// laying them out with their offsets in an array. Other boolean properties are collected.
class PrimitiveExtractor {
enum {
unknown_element = 1, ///< Contains at least one TYPE_UNKNOWN primitive
unaligned = 2, ///< At least one primitive is not properly aligned
extra_space = 4, ///< Data-type contains empty space not attributable to alignment padding
invalid = 8, ///< Data-type exceeded maximum or contained illegal elements
union_invalid = 16 ///< Unions are treated as an illegal element
};
public:
/// \brief A primitive data-type and its offset within the containing data-type
class Primitive {
public:
Datatype *dt; ///< Primitive data-type
int4 offset; ///< Offset within container
Primitive(Datatype *d,int4 off) { dt = d; offset = off; } ///< Constructor
};
private:
vector<Primitive> primitives; ///< List of extracted primitives
uint4 flags; ///< Boolean properties of the data-type
int4 checkOverlap(vector<Primitive> &res,vector<Primitive> &small,int4 point,Primitive &big);
bool commonRefinement(vector<Primitive> &first,vector<Primitive> &second);
bool handleUnion(TypeUnion *dt,int4 max,int4 offset); ///< Add primitives representing a union data-type
bool extract(Datatype *dt,int4 max,int4 offset); ///< Extract list of primitives from given data-type
public:
PrimitiveExtractor(Datatype *dt,bool unionIllegal,int4 offset,int4 max); ///< Constructor
int4 size(void) const { return primitives.size(); } ///< Return the number of primitives extracted
const Primitive &get(int4 i) const { return primitives[i]; } ///< Get a particular primitive
bool isValid(void) const { return (flags & invalid) == 0; } ///< Return \b true if primitives were successfully extracted
bool containsUnknown(void) const { return (flags & unknown_element)!=0; } ///< Are there \b unknown elements
bool isAligned(void) const { return (flags & unaligned)==0; } ///< Are all elements aligned
bool containsHoles(void) const { return (flags & extra_space)!=0; } ///< Is there empty space that is not padding
};
/// \brief A filter selecting a specific class of data-type
///
/// An instance is configured via the decode() method, then a test of whether
/// a data-type belongs to its class can be performed by calling the filter() method.
class DatatypeFilter {
public:
virtual ~DatatypeFilter(void) {} ///< Destructor
/// \brief Make a copy of \b this filter
///
/// \return the newly allocated copy
virtual DatatypeFilter *clone(void) const=0;
/// \brief Test whether the given data-type belongs to \b this filter's data-type class
///
/// \param dt is the given data-type to test
/// \return \b true if the data-type is in the class, \b false otherwise
virtual bool filter(Datatype *dt) const=0;
/// \brief Configure details of the data-type class being filtered from the given stream
///
/// \param decoder is the given stream decoder
virtual void decode(Decoder &decoder)=0;
static DatatypeFilter *decodeFilter(Decoder &decoder); ///< Instantiate a filter from the given stream
};
/// \brief A common base class for data-type filters that tests for a size range
///
/// Any filter that inherits from \b this, can use ATTRIB_MINSIZE and ATTRIB_MAXSIZE
/// to place bounds on the possible sizes of data-types. The bounds are enforced
/// by calling filterOnSize() within the inheriting classes filter() method.
class SizeRestrictedFilter : public DatatypeFilter {
protected:
int4 minSize; ///< Minimum size of the data-type in bytes
int4 maxSize; ///< Maximum size of the data-type in bytes
public:
SizeRestrictedFilter(void) { minSize=0; maxSize=0; } ///< Constructor for use with decode()
SizeRestrictedFilter(int4 min,int4 max); ///< Constructor
bool filterOnSize(Datatype *dt) const; ///< Enforce any size bounds on a given data-type
virtual DatatypeFilter *clone(void) const { return new SizeRestrictedFilter(minSize,maxSize); }
virtual bool filter(Datatype *dt) const { return filterOnSize(dt); }
virtual void decode(Decoder &decoder);
};
/// \brief Filter on a single meta data-type
///
/// Filters on TYPE_STRUCT or TYPE_FLOAT etc. Additional filtering on size of the data-type can be configured.
class MetaTypeFilter : public SizeRestrictedFilter {
protected:
type_metatype metaType; ///< The meta-type this filter lets through
public:
MetaTypeFilter(type_metatype meta); ///< Constructor for use with decode()
MetaTypeFilter(type_metatype meta,int4 min,int4 max); ///< Constructor
virtual DatatypeFilter *clone(void) const { return new MetaTypeFilter(metaType,minSize,maxSize); }
virtual bool filter(Datatype *dt) const;
};
/// \brief Filter on a homogeneous aggregate data-type
///
/// All primitive data-types must be the same.
class HomogeneousAggregate : public SizeRestrictedFilter {
type_metatype metaType; ///< The expected meta-type
int4 maxPrimitives; ///< Maximum number of primitives in the aggregate
public:
HomogeneousAggregate(type_metatype meta); ///< Constructor for use with decode()
HomogeneousAggregate(type_metatype meta,int4 maxPrim,int4 min,int4 max); ///< Constructor
virtual DatatypeFilter *clone(void) const { return new HomogeneousAggregate(metaType,maxPrimitives, minSize,maxSize); }
virtual bool filter(Datatype *dt) const;
};
/// \brief A filter on some aspect of a specific function prototype
///
/// An instance is configured via the decode() method, then a test of whether
/// a function prototype meets its criteria can be performed by calling its filter() method.
class QualifierFilter {
public:
virtual ~QualifierFilter(void) {} ///< Destructor
/// \brief Make a copy of \b this qualifier
///
/// \return the newly allocated copy
virtual QualifierFilter *clone(void) const=0;
/// \brief Test whether the given function prototype meets \b this filter's criteria
///
/// \param proto is the high-level description of the function prototype to test
/// \param pos is the position of a specific output (pos=-1) or input (pos >=0) in context
/// \return \b true if the prototype meets the criteria, \b false otherwise
virtual bool filter(const PrototypePieces &proto,int4 pos) const=0;
/// \brief Configure details of the criteria being filtered from the given stream
///
/// \param decoder is the given stream decoder
virtual void decode(Decoder &decoder) {}
static QualifierFilter *decodeFilter(Decoder &decoder); ///< Try to instantiate a qualifier filter
};
/// \brief Logically AND multiple QualifierFilters together into a single filter
///
/// An instances contains some number of other arbitrary filters. In order for \b this filter to
/// pass, all these contained filters must pass.
class AndFilter : public QualifierFilter {
vector<QualifierFilter *> subQualifiers; ///< Filters being logically ANDed together
public:
AndFilter(vector<QualifierFilter *> filters); ///< Construct from array of filters
virtual ~AndFilter(void);
virtual QualifierFilter *clone(void) const;
virtual bool filter(const PrototypePieces &proto,int4 pos) const;
virtual void decode(Decoder &decoder) {}
};
/// \brief A filter that selects function parameters that are considered optional
///
/// If the underlying function prototype is considered to take variable arguments, the first
/// \e n parameters (as determined by PrototypePieces.firstVarArgSlot) are considered non-optional.
/// If additional data-types are provided beyond the initial \e n, these are considered optional.
/// This filter returns \b true for these optional parameters
class VarargsFilter : public QualifierFilter {
public:
virtual QualifierFilter *clone(void) const { return new VarargsFilter(); }
virtual bool filter(const PrototypePieces &proto,int4 pos) const;
virtual void decode(Decoder &decoder);
};
/// \brief Filter that selects for a particular parameter position
///
/// This matches if the position of the current parameter being assigned, within the data-type
/// list, matches the \b position attribute of \b this filter.
class PositionMatchFilter : public QualifierFilter {
int4 position; ///< Parameter position being filtered for
public:
PositionMatchFilter(int4 pos) { position = pos; } ///< Constructor
virtual QualifierFilter *clone(void) const { return new PositionMatchFilter(position); }
virtual bool filter(const PrototypePieces &proto,int4 pos) const;
virtual void decode(Decoder &decoder);
};
/// \brief Check if the function signature has a specific data-type in a specific position
/// This filter does not match against the data-type in the current position
/// being assigned, but against a parameter at a fixed position.
class DatatypeMatchFilter : public QualifierFilter {
int4 position; ///< The position of the data-type to check
DatatypeFilter *typeFilter; ///< The data-type that must be at \b position
public:
DatatypeMatchFilter(void) { position = -1; typeFilter = (DatatypeFilter *)0; } ///< Constructor for use with decode
virtual ~DatatypeMatchFilter(void);
virtual QualifierFilter *clone(void) const;
virtual bool filter(const PrototypePieces &proto,int4 pos) const;
virtual void decode(Decoder &decoder);
};
/// \brief An action that assigns an Address to a function prototype parameter
///
/// A request for the address of either \e return storage or an input parameter is made
/// through the assignAddress() method, which is given full information about the function prototype.
/// Details about how the action performs is configured through the decode() method.
class AssignAction {
public:
enum {
success, ///< Data-type is fully assigned
fail, ///< Action could not be applied
no_assignment, ///< Do not assign storage for this parameter
hiddenret_ptrparam, ///< Hidden return pointer as first input parameter
hiddenret_specialreg, ///< Hidden return pointer in dedicated input register
hiddenret_specialreg_void ///< Hidden return pointer, but no normal return
};
protected:
const ParamListStandard *resource; ///< Resources to which this action applies
bool fillinOutputActive; ///< If \b true, fillinOutputMap is active
public:
AssignAction(const ParamListStandard *res) {resource = res; fillinOutputActive = false; } ///< Constructor
bool canAffectFillinOutput(void) const { return fillinOutputActive; } ///< Return \b true if fillinOutputMap is active
virtual ~AssignAction(void) {}
/// \brief Make a copy of \b this action
///
/// \param newResource is the new resource object that will own the clone
/// \return the newly allocated copy
virtual AssignAction *clone(const ParamListStandard *newResource) const=0;
/// \brief Assign an address and other meta-data for a specific parameter or for return storage in context
///
/// The Address is assigned based on the data-type of the parameter, available register
/// resources, and other details of the function prototype. Consumed resources are marked.
/// This method returns a response code:
/// - success - indicating the Address was successfully assigned
/// - fail - if the Address could not be assigned
/// - hiddenret_ptrparam - if an additional \e hidden \e return \e parameter is required
///
/// \param dt is the data-type of the parameter or return value
/// \param proto is the high-level description of the function prototype
/// \param pos is the position of the parameter (pos>=0) or return storage (pos=-1)
/// \param tlist is a data-type factory for (possibly) transforming the data-type
/// \param status is the resource consumption array
/// \param res will hold the resulting description of the parameter
/// \return the response code
virtual uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const=0;
/// \brief Test if \b this action could produce return value storage matching the given set of trials
///
/// If there is a return value data-type that could be assigned storage matching the trials by \b this action,
/// return \b true. The trials have their matching ParamEntry and offset already set and are already sorted.
/// \param active is the given set of trials
/// \return \b true if the trials could form a valid return value
virtual bool fillinOutputMap(ParamActive *active) const;
/// \brief Configure any details of how \b this action should behave from the stream
///
/// \param decoder is the given stream decoder
virtual void decode(Decoder &decoder)=0;
static AssignAction *decodeAction(Decoder &decoder,const ParamListStandard *res);
static AssignAction *decodeSideeffect(Decoder &decoder,const ParamListStandard *res);
};
/// \brief Action assigning a parameter Address from the next available stack location
class GotoStack : public AssignAction {
const ParamEntry *stackEntry; ///< Parameter Entry corresponding to the stack
void initializeEntry(void); ///< Find stack entry in resource list
public:
GotoStack(const ParamListStandard *res,int4 val); ///< Constructor for use with decode
GotoStack(const ParamListStandard *res); ///< Constructor for use with decode()
virtual AssignAction *clone(const ParamListStandard *newResource) const { return new GotoStack(newResource); }
virtual uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const;
virtual bool fillinOutputMap(ParamActive *active) const;
virtual void decode(Decoder &decoder);
};
/// \brief Action converting the parameter's data-type to a pointer, and assigning storage for the pointer
///
/// This assumes the data-type is stored elsewhere and only the pointer is passed as a parameter
class ConvertToPointer : public AssignAction {
AddrSpace *space; ///< Address space used for pointer size
public:
ConvertToPointer(const ParamListStandard *res); ///< Constructor for use with decode()
virtual AssignAction *clone(const ParamListStandard *newResource) const { return new ConvertToPointer(newResource); }
virtual uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const;
virtual void decode(Decoder &decoder);
};
/// \brief Consume multiple registers to pass a data-type
///
/// Available registers are consumed until the data-type is covered, and an appropriate
/// \e join space address is assigned. Registers can be consumed from a specific resource list.
/// Consumption can spill over onto the stack if desired.
class MultiSlotAssign : public AssignAction {
type_class resourceType; ///< Resource list from which to consume
bool consumeFromStack; ///< True if resources should be consumed from the stack
bool consumeMostSig; ///< True if resources are consumed starting with most significant bytes
bool enforceAlignment; ///< True if register resources are discarded to match alignment
bool justifyRight; ///< True if initial bytes are padding for odd data-type sizes
const ParamEntry *stackEntry; ///< The stack resource
list<ParamEntry>::const_iterator firstIter; ///< Iterator to first element in the resource list
void initializeEntries(void); ///< Cache specific ParamEntry needed by the action
public:
MultiSlotAssign(const ParamListStandard *res); ///< Constructor for use with decode
MultiSlotAssign(type_class store,bool stack,bool mostSig,bool align,bool justRight,const ParamListStandard *res); ///< Constructor
virtual AssignAction *clone(const ParamListStandard *newResource) const {
return new MultiSlotAssign(resourceType,consumeFromStack,consumeMostSig,enforceAlignment,justifyRight,newResource); }
virtual uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const;
virtual bool fillinOutputMap(ParamActive *active) const;
virtual void decode(Decoder &decoder);
};
/// \brief Consume a register per primitive member of an aggregate data-type
///
/// The data-type is split up into its underlying primitive elements, and each one
/// is assigned a register from the specific resource list. There must be no padding between
/// elements. No packing of elements into a single register occurs.
class MultiMemberAssign : public AssignAction {
type_class resourceType; ///< Resource list from which to consume
bool consumeFromStack; ///< True if resources should be consumed from the stack
bool consumeMostSig; ///< True if resources are consumed starting with most significant bytes
public:
MultiMemberAssign(type_class store,bool stack,bool mostSig,const ParamListStandard *res); ///< Constructor
virtual AssignAction *clone(const ParamListStandard *newResource) const {
return new MultiMemberAssign(resourceType,consumeFromStack,consumeMostSig,newResource); }
virtual uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const;
virtual bool fillinOutputMap(ParamActive *active) const;
virtual void decode(Decoder &decoder);
};
/// \brief Consume multiple registers from different storage classes to pass a data-type
///
/// This action is for calling conventions that can use both floating-point and general purpose registers
/// when assigning storage for a single composite data-type, such as the X86-64 System V ABI
class MultiSlotDualAssign : public AssignAction {
type_class baseType; ///< Resource list from which to consume general tiles
type_class altType; ///< Resource list from which to consume alternate tiles
bool consumeMostSig; ///< True if resources are consumed starting with most significant bytes
bool justifyRight; ///< True if initial bytes are padding for odd data-type sizes
int4 tileSize; ///< Number of bytes in a tile
list<ParamEntry>::const_iterator baseIter; ///< Iterator to first element in the base resource list
list<ParamEntry>::const_iterator altIter; ///< Iterator to first element in alternate resource list
void initializeEntries(void); ///< Cache specific ParamEntry needed by the action
list<ParamEntry>::const_iterator getFirstUnused(list<ParamEntry>::const_iterator iter,type_class storage,
vector<int4> &status) const;
int4 getTileClass(const PrimitiveExtractor &primitives,int4 off,int4 &index) const;
public:
MultiSlotDualAssign(const ParamListStandard *res); ///< Constructor for use with decode
MultiSlotDualAssign(type_class baseStore,type_class altStore,bool mostSig,bool justRight,
const ParamListStandard *res); ///< Constructor
virtual AssignAction *clone(const ParamListStandard *newResource) const {
return new MultiSlotDualAssign(baseType,altType,consumeMostSig,justifyRight,newResource); }
virtual uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const;
virtual bool fillinOutputMap(ParamActive *active) const;
virtual void decode(Decoder &decoder);
};
/// \brief Consume a parameter from a specific resource list
///
/// Normally the resource list is determined by the parameter data-type, but this
/// action specifies an overriding resource list. Assignment will \e not fall through to the stack.
class ConsumeAs : public AssignAction {
type_class resourceType; ///< The resource list the parameter is consumed from
public:
ConsumeAs(type_class store,const ParamListStandard *res); ///< Constructor
virtual AssignAction *clone(const ParamListStandard *newResource) const {
return new ConsumeAs(resourceType,newResource); }
virtual uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const;
virtual bool fillinOutputMap(ParamActive *active) const;
virtual void decode(Decoder &decoder);
};
/// \brief Allocate the return value as an input parameter
///
/// A pointer to where the return value is to be stored is passed in as an input parameter.
/// This action signals this by returning one of
/// - \b hiddenret_ptrparam - indicating the pointer is allocated as a normal input parameter
/// - \b hiddenret_specialreg - indicating the pointer is passed in a dedicated register
/// - \b hiddenret_specialreg_void
///
/// Usually, if a hidden return input is present, the normal register used for return
/// will also hold the pointer at the point(s) where the function returns. A signal of
/// \b hiddenret_specialreg_void indicates the normal return register is not used to pass back
/// the pointer.
class HiddenReturnAssign : public AssignAction {
uint4 retCode; ///< The specific signal to pass back
public:
HiddenReturnAssign(const ParamListStandard *res,uint4 code); ///< Constructor
virtual AssignAction *clone(const ParamListStandard *newResource) const {
return new HiddenReturnAssign(newResource, retCode); }
virtual uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const;
virtual void decode(Decoder &decoder);
};
/// \brief Consume additional registers from an alternate resource list
///
/// This action is a side-effect and doesn't assign an address for the current parameter.
/// The resource list, \b resourceType, is specified. If the side-effect is triggered,
/// register resources from this list are consumed. If \b matchSize is true (the default),
/// registers are consumed, until the number of bytes in the data-type is reached. Otherwise,
/// only a single register is consumed. If all registers are already consumed, no action is taken.
class ConsumeExtra : public AssignAction {
type_class resourceType; ///< The other resource list to consume from
list<ParamEntry>::const_iterator firstIter; ///< Iterator to first element in the resource list
bool matchSize; ///< \b false, if side-effect only consumes a single register
void initializeEntries(void); ///< Cache specific ParamEntry needed by the action
public:
ConsumeExtra(const ParamListStandard *res); ///< Constructor for use with decode
ConsumeExtra(type_class store,bool match,const ParamListStandard *res); ///< Constructor
virtual AssignAction *clone(const ParamListStandard *newResource) const {
return new ConsumeExtra(resourceType,matchSize,newResource); }
virtual uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const;
virtual void decode(Decoder &decoder);
};
/// \brief A rule controlling how parameters are assigned addresses
///
/// Rules are applied to a parameter in the context of a full function prototype.
/// A rule applies only for a specific class of data-type associated with the parameter, as
/// determined by its DatatypeFilter, and may have other criteria limiting when it applies
/// (via QualifierFilter).
class ModelRule {
DatatypeFilter *filter; ///< Which data-types \b this rule applies to
QualifierFilter *qualifier; ///< Additional qualifiers for when the rule should apply (if non-null)
AssignAction *assign; ///< How the Address should be assigned
vector<AssignAction *> sideeffects; ///< Extra actions that happen on success
public:
ModelRule(void) {
filter = (DatatypeFilter *)0; qualifier = (QualifierFilter *)0; assign = (AssignAction *)0; } ///< Constructor for use with decode
ModelRule(const ModelRule &op2,const ParamListStandard *res); ///< Copy constructor
ModelRule(const DatatypeFilter &typeFilter,const AssignAction &action,const ParamListStandard *res); ///< Construct from components
~ModelRule(void); ///< Destructor
uint4 assignAddress(Datatype *dt,const PrototypePieces &proto,int4 pos,TypeFactory &tlist,
vector<int4> &status,ParameterPieces &res) const;
bool fillinOutputMap(ParamActive *active) const; ///< Test and mark the trial(s) that can be valid return value
bool canAffectFillinOutput(void) const; ///< Return \b true if fillinOutputMap is active for \b this rule
void decode(Decoder &decoder,const ParamListStandard *res); ///< Decode \b this rule from stream
};
/// If the assign action could produce the trials as return value storage, return \b true
/// \param active is the set of trials
/// \return \b true if the trials form a return value
inline bool ModelRule::fillinOutputMap(ParamActive *active) const
{
return assign->fillinOutputMap(active);
}
/// \return \b true if the assign action can affect fillinOutputMap()
inline bool ModelRule::canAffectFillinOutput(void) const
{
return assign->canAffectFillinOutput();
}
} // End namespace ghidra
#endif