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/*
* phc -- the open source PHP compiler
* See doc/license/README.license for licensing information
*
* Try to model functions as accurately as possible.
*/
#ifndef PHC_METHOD_INFORMATION
#define PHC_METHOD_INFORMATION
#include "CFG.h"
// There is a ton of information here, and we don't want to extend the
// MIR::Signature and MIR::Formal_parameters with it, since they're used in
// lots of other places.
/*
* What can go wrong, and what information do we get automatically:
*
* Parameters:
*
* - parameters can be passed by reference (we can know this)
* - a parameter can be an object
* - the obj/reference can be modified by the callee
* - a parameter can be the name of a callback
* - the callback can be the result of create_function
* - a parameter can have a magic method called on it by the way it is
* accessed
* - a function can be called with the wrong number of parameters, so
* might do nothing and return NULL.
*
* Methods:
* - a method has paramters (see above)
* - a method may change global variables
* - a method may change local variables
* - a method can be side-effecting (we'd like to model if it is not, so
* that calls can be removed).
* - a method may return-by-ref.
*
*
* The only answer is to assume the worst in all cases, and to selectively
* model functions to not do so badly. However, we are able to model some
* things automatically:
*
* - user code:
* - can determine by analysis:
* - is_side_effecting
* - can tell very easily
* - return-by-ref
* - pass-by-ref
*
* - built-in-functions
* - return-by-ref
* - pass-by-ref
*
*
* Solution:
*
* Remove all the information from method_info. The only thing that should
* be there is return-by-ref and pass-by-ref.
*
* Add methods to Method_info allowing us to check for what we need. Add a
* function to automatically apply what we know when a function is called.
*
* Method_info should have no public members. Remove Param_info.
*
* Embed can provide hooks that take a method_name.
*
*/
DECL (Method_info);
DECL (Class_info);
DECL (User_class_info);
String* UNNAMED (int param_index);
MIR::VARIABLE_NAME* unnamed_param (int param_index);
class Method_info : virtual public GC_obj
{
public:
String* name;
String* lc_name;
protected:
CFG* cfg; // If there is no implementation, a fake CFG is provided.
Method_info (String* name);
public:
virtual bool has_implementation () = 0;
/*
* Model signature (an MIR::Signature isnt really good enough, and is very
* annoying to use).
*/
virtual bool return_by_ref () = 0;
virtual MIR::VARIABLE_NAME* param_name (int param_index) = 0;
virtual bool param_by_ref (int param_index) = 0;
// Returns NULL if there is a default parameter for this index
virtual MIR::Static_value* default_param (int param_index) = 0;
virtual int formal_param_count () = 0;
virtual Class_info* get_class_info () = 0;
virtual CFG* get_cfg () = 0;
/*
* Annotations for optimizations
*/
virtual bool get_side_effecting () = 0;
};
class User_method_info : public Method_info
{
private:
User_class_info* class_info;
MIR::Method* method;
MIR::Signature* signature;
bool side_effecting;
public:
User_method_info (MIR::Method* implementation);
User_method_info (User_class_info* class_info, MIR::Method* method);
bool has_implementation ();
bool return_by_ref ();
MIR::VARIABLE_NAME* param_name (int param_index);
bool param_by_ref (int param_index);
MIR::Static_value* default_param (int param_index);
int formal_param_count ();
bool get_side_effecting ();
void set_side_effecting (bool);
MIR::Method* get_method ();
virtual Class_info* get_class_info ();
virtual CFG* get_cfg ();
};
class Summary_method_info : public Method_info
{
public:
// Creates fake CFGs for summary analysis
Summary_method_info (String* name);
virtual Class_info* get_class_info ();
virtual CFG* get_cfg ();
Basic_block* get_fake_bb ();
};
/*
* Model builtin functions. The modelling is actually in Whole_program.cpp, for
* now.
*/
class Builtin_method_info : public Summary_method_info
{
public:
Builtin_method_info (String* name);
bool has_implementation ();
bool return_by_ref ();
MIR::VARIABLE_NAME* param_name (int param_index);
bool param_by_ref (int param_index);
MIR::Static_value* default_param (int param_index);
int formal_param_count ();
bool get_side_effecting ();
virtual Class_info* get_class_info ();
};
#endif // PHC_METHOD_INFORMATION
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