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unification.h Go to the documentation of this file. // ---------------------------------------------------------------------- // // C-Breeze // C Compiler Framework // // Copyright (c) 2000 University of Texas at Austin // // Teck Bok Tok // Samuel Z. Guyer // Daniel A. Jimenez // Calvin Lin // // Permission is hereby granted, free of charge, to any person // obtaining a copy of this software and associated documentation // files (the "Software"), to deal in the Software without // restriction, including without limitation the rights to use, copy, // modify, merge, publish, distribute, sublicense, and/or sell copies // of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be // included in all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND // NONINFRINGEMENT. IN NO EVENT SHALL THE UNIVERSITY OF TEXAS AT // AUSTIN BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER // IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF // OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. // // We acknowledge the C-to-C Translator from MIT Laboratory for // Computer Science for inspiring parts of the C-Breeze design. // // ---------------------------------------------------------------------- #ifndef UNIFICATION_H #define UNIFICATION_H #include "c_breeze.h" class Linker; /* Algorithm source: Bjarne Steensgaard. Points-to Analysis in Almost Linear Time. In Symposium on Principles of Programming Languages, pages 32--41, 1996 */ class Unify_ECR; class Unify_Offset; class Unify_Size; class UnifyType; class UnificationBasedPtr; class Unify_Pending; class Unify_Pendings { set<Unify_Pending*> _set; bool cleaned; public: Unify_Pendings() : cleaned(true) {} inline bool empty() const { return _set.empty(); } inline int size() const { return _set.size(); } inline void clear() { _set.clear(); } inline set<Unify_Pending*> set() const { return _set; } void insert(Unify_Pending *p, bool is_new); void cleanup(); }; // Unify_Pendings //%{ /* Unify_ECR's */ class Unify_ECR { protected: REF declNode *_var; REF procNode *_proc; REF Unify_ECR *_parent, *_root; int _ndecestors; set<Unify_ECR*> _children; Unify_Pendings _pending; TREE int _id; TREE UnifyType *_type; static int id_count; static set<Unify_ECR*> all_ECR; public: Unify_ECR(declNode *v, procNode *p); Unify_ECR(UnifyType *t); inline declNode *var() const { return _var; } inline void var(declNode *d) { _var = d; } inline procNode *proc() const { return _proc; } inline void proc(procNode *p) { _proc=p; } inline Unify_ECR *parent() const { return _parent; } inline void parent(Unify_ECR *p) { _root = _parent = p; } Unify_ECR * root(); inline Unify_Pendings & pending() { return _pending; } inline int id() const { return _id; } bool operator==(Unify_ECR &other) { return root()==other.root(); } Unify_ECR * Union(Unify_ECR *other); decl_list all_decls() const; UnifyType * type(); void type(UnifyType *t); void print(); inline friend ostream & operator<<(ostream &o, Unify_ECR &ecr) { ecr.print(); return o; } static set<Unify_ECR*> allECR() { return all_ECR; } }; // Unify_ECR //%} //%{ /* misc */ class Unify_Offset { public: typedef enum { zero, unknown } Value; private: Value _value; Unify_Pendings _pending; public: Unify_Offset(Value v) : _value(v) {} inline Value value() const { return _value; } inline void value(Value v) { _value=v; } inline Unify_Pendings & pending() { return _pending; } inline bool leq(Unify_Offset *o) const { return _value==zero || _value==o->_value;} inline void print() const { cout << (_value==zero ? "zero" : "unknown"); } inline friend ostream & operator<<(ostream &o, const Unify_Offset &off) { off.print(); return o; } }; class Alpha { Unify_ECR *_tao; Unify_Offset *_offset; public: Alpha(Unify_ECR *t, Unify_Offset *o) : _tao(t), _offset(o) { assert(t && o); } Alpha(); inline Unify_ECR *tao() const { return _tao; } inline Unify_Offset *offset() const { return _offset; } bool leq(Alpha *o, Unify_Size s) const; bool equal(Alpha *o) { return _tao->type()==o->tao()->type() && _offset->value()==o->offset()->value(); } void print() const; inline friend ostream & operator<<(ostream &o, const Alpha &a) { a.print(); return o; } }; typedef set<declNode*> declSet; typedef list<declSet> FieldOrder; typedef list<typeNode*> FieldTypeOrder; typedef map<declSet,Unify_ECR*> EltMap; class Lambda { int _n,_m; bool _ellipsis; // contain ellipsis? Unify_ECR **_taos, *_taoR; // array of tao bool _is_bottom; int _id; Unify_Pendings _pending; static int id_count; public: /*Lambda(int n, int m, ECR **t) : _n(n), _m(m), _taos(t), _is_bottom(false), _ellipsis(false), _id(id_count++) {}*/ Lambda() : _is_bottom(true), _ellipsis(false), _n(0), _m(0), _taos(NULL), _taoR(NULL), _id(id_count++) {} inline int id() const { return _id; } inline bool is_bottom() const { return _is_bottom; } inline int n() const { return _n; } inline int m() const { return _m; } inline bool ellipsis() const { return _ellipsis; } inline Unify_ECR *tao(int i) const { assert(i<_n); return _taos[i]; } inline void tao(int i, Unify_ECR *t) { assert(i<_n); _taos[i]=t; } inline Unify_ECR *taoR() const { assert(0<_m); return _taoR; } inline void taoR(Unify_ECR *r) { assert(0<_m); _taoR=r; } inline Unify_Pendings & pending() { return _pending; } void settype(int n, int m, Unify_ECR **t, Unify_ECR *r, bool ellipse); void addArg(int plus_n); inline bool leq(Lambda *o) const { return is_bottom() || equal(o); } bool equal(Lambda *o) const; void print() const; inline friend ostream & operator<<(ostream &o, const Lambda &l) { l.print(); return o; } static Lambda * bottom(); }; // Lambda class Unify_Size { bool _is_top; int _size; public: Unify_Size(int size) : _size(size), _is_top(size<=0 ? true : false) {} Unify_Size() : _size(0), _is_top(true) {} inline bool is_top() const { return _is_top; } inline int size() const { return _size; } inline bool leq(Unify_Size o) const { return _size==o.size() || o.is_top(); } inline bool equal(Unify_Size o) { return _size==o.size() && _is_top==o.is_top(); } string str() const; static int sizeOf(typeNode *ty); static int sizeOfAssign(threeAddrNode *t, Linker &, UnificationBasedPtr *); }; class Unify_Parents { set<Unify_ECR*> _parents; bool _is_top; public: Unify_Parents(set<Unify_ECR*> parents) : _parents(parents), _is_top(false) {} Unify_Parents(bool top) : _is_top(top) {} inline bool is_top() const { return _is_top; } inline void top(bool t) { _is_top=t; } inline bool empty() const { return !_is_top && _parents.empty(); } inline bool equal(Unify_Parents o) { return _parents==o.parents() && _is_top==o.is_top(); } inline set<Unify_ECR*> & parents() { return _parents; } string str() const; }; //%} //%{ /* UnifyType's types */ typedef enum { BOTTOM, SIMPLE, STRUCTURE, OBJECT, BLANK } Object_Typ; typedef struct Unify_Simple { Alpha *alpha; Lambda *lambda; Unify_Size s; Unify_Parents p; Unify_Simple(Alpha *a, Lambda *l, Unify_Size _s, Unify_Parents _p) : alpha(a), lambda(l), s(_s), p(_p) { } } Unify_Simple; typedef struct Unify_Structure { FieldOrder fo; FieldTypeOrder fto; EltMap m; Unify_Size s; Unify_Parents p; Unify_Structure(suespecNode *sue, EltMap _m, Unify_Size _s, Unify_Parents _p); Unify_Structure(FieldOrder _fo, FieldTypeOrder _fto, EltMap _m, Unify_Size _s, Unify_Parents _p) : fo(_fo), fto(_fto), m(_m), s(_s), p(_p){} Unify_ECR *get(declNode *field, Unify_ECR *container); string map_str(); string all_str(); } Unify_Structure; typedef struct Unify_Object { Alpha *alpha; Lambda *lambda; Unify_Size s; Unify_Parents p; Unify_Object(Alpha *a, Lambda *l, Unify_Size _s, Unify_Parents _p) : alpha(a), lambda(l), s(_s), p(_p) {} } Unify_Object; typedef struct Unify_Blank { Unify_Size s; Unify_Parents p; Unify_Blank(Unify_Size _s, Unify_Parents _p) : s(_s), p(_p) {} } Unify_Blank; //%} class memoryBlock; //%{ /* actual type */ class UnifyType { private: Unify_ECR *_ecr; int _id; static int id_count; union { Unify_Simple *simple; Unify_Structure *structure; Unify_Object *object; Unify_Blank *blank; } _tao; Object_Typ obj_typ; memoryBlock *_block; set<procNode*> _procs; // NEW: this type represent this set of procedures. bool _is_bottom; public: UnifyType() : obj_typ(BOTTOM), _is_bottom(true), _id(id_count++), _block(0) { _ecr=new Unify_ECR(this); } UnifyType(Unify_Simple *s) : obj_typ(SIMPLE),_is_bottom(false),_id(id_count++) { _block=0; _tao.simple=s; _ecr=new Unify_ECR(this); } UnifyType(Unify_Structure *s) : obj_typ(STRUCTURE), _is_bottom(false), _id(id_count++), _block(0) { _tao.structure=s; _ecr=new Unify_ECR(this); } UnifyType(Unify_Object *o) : obj_typ(OBJECT),_is_bottom(false),_id(id_count++) { _block=0; _tao.object=o; _ecr=new Unify_ECR(this); } UnifyType(Unify_Blank *b) : obj_typ(BLANK), _is_bottom(false), _id(id_count++) { _block=0; _tao.blank=b; _ecr=new Unify_ECR(this); } UnifyType(Unify_Blank *b, Unify_ECR *ecr) : obj_typ(BLANK), _is_bottom(false), _id(id_count++) { _block=0; _tao.blank=b; _ecr=ecr; } inline Unify_ECR *ecr() const { if(_ecr) return _ecr->root(); return _ecr; } inline Unify_ECR *ecr_no_root() const { return _ecr; } inline void ecr(Unify_ECR *ecr) { _ecr=ecr; } inline bool is_bottom() const { return _is_bottom; } inline int id() const { return _id; } inline Object_Typ objTyp() const { return obj_typ; } inline memoryBlock *block() const { return _block; } inline void block(memoryBlock *b) { _block=b; } inline set<procNode*> & procs() { return _procs; } inline Unify_Simple *simple() const { assert(obj_typ==SIMPLE); return _tao.simple; } inline Unify_Structure *structure() const { assert(obj_typ==STRUCTURE); return _tao.structure; } inline Unify_Object *object() const { assert(obj_typ==OBJECT); return _tao.object; } inline Unify_Blank *blank() const { assert(obj_typ==BLANK); return _tao.blank; } inline bool leq(UnifyType *o, Unify_Size s) const { return this==o || s.leq(size()); } Unify_Size size() const; void print() const; inline friend ostream & operator<<(ostream &o, const UnifyType &t) { t.print(); return o; } static UnifyType *toTao(UnifyType *t); static inline UnifyType *bottom() { return new UnifyType(); } }; // UnifyType #define T_bottom UnifyType::bottom() #define L_bottom Lambda::bottom() //%} class Unify_Pending { public: typedef enum { makeunknown, join_ECR, join_Lambda, cjoin, collapse } Typ; private: Typ _typ; void *_arg1, *_arg2, *_arg3; bool _served; public: Unify_Pending(Unify_ECR *e1, Unify_ECR *e2) : _typ(join_ECR), _arg1(e1), _arg2(e2), _arg3(NULL), _served(false) {} Unify_Pending(Lambda *l1, Lambda *l2) : _typ(join_Lambda), _arg1(l1), _arg2(l2), _arg3(NULL), _served(false) {} Unify_Pending(Unify_Offset *o) : _typ(makeunknown), _arg1(o), _arg2(NULL), _arg3(NULL), _served(false) {} Unify_Pending(Unify_ECR *e) : _typ(collapse), _arg1(e), _arg2(NULL), _arg3(NULL), _served(false) {} Unify_Pending(Unify_Size &s, Unify_ECR *e1, Unify_ECR *e2) : _typ(cjoin), _arg1(new Unify_Size(s)), _arg2(e1), _arg3(e2), _served(false) {} ~Unify_Pending() { if(_typ==cjoin) delete (Unify_Size*) _arg1; } inline Typ typ() const { return _typ; } inline void *arg1() const { return _arg1; } inline void *arg2() const { return _arg2; } inline void *arg3() const { return _arg3; } inline bool is_served() const { return _served; } inline void served() { _served=true; } inline void un_served() { _served=false; } void print() const; inline friend ostream & operator<<(ostream &o, const Unify_Pending &p) { p.print(); return o; } }; typedef set<Unify_Pending*>::iterator Pendings_p; typedef set<UnifyType*> UnifyTypes; class memoryModel; class stmtLocation; class procLocation; class UnificationBasedPtr : public Walker { public: static UnificationBasedPtr *analyze_all(Linker &); inline Unify_ECR *ecr(declNode *decl) const { if(_ecr.find(decl) != _ecr.end()) return _ecr.find(decl)->second; return NULL; } inline Unify_ECR *ecr(threeAddrNode *alloc_site) const { if(_alloc.find(alloc_site) != _alloc.end()) return _alloc.find(alloc_site)->second; return NULL; } inline UnifyType *proctype(procNode *p) { return _proctype[p]; } void createProcBlock(procNode *, memoryModel &, procLocation*); // annotation mark this stmt as it create obj virtual void mark_alloc(stmtNode *stmt, declNode *source_decl, declNode *target_decl) {} void ensure_no_bottom(Unify_ECR *tao, declNode *decl, UnifyType *parent); // new virtual bool isField(declNode *f, bool &from_annotation) const { from_annotation = false; return _unique_field_defn.find(f) != _unique_field_defn.end(); } Unify_ECR *ecrField(UnifyType *container, declNode *field, bool field_from_annotation); Unify_ECR *ecrDeref(UnifyType *container); static bool reachable(UnifyType *src, UnifyTypes & targets, UnifyTypes & visited); inline Alpha *string_alpha(constNode *con) { return _string_alpha[con]; } set<Unify_ECR*> unique_ecr() const; inline procNode *synthetic_proc(declNode *d) { return _synthetic_proc[d]; } static bool compatible_type(typeNode *, typeNode *); void print_ecr(); static int unify_points_to_max; protected: TREE map<declNode*, Unify_ECR*> _ecr; TREE map<procNode*, UnifyType*> _proctype; TREE map<threeAddrNode*, Unify_ECR*> _alloc; // ecr for allocation sites TREE map<constNode*,Alpha*> _string_alpha; //#tmp vars created by diamantler TREE int _dismantler_tmp; TREE map<declNode*, suespecNode*> _field2sue; TREE map<declNode*, decl_list> _fieldpos; TREE set<suespecNode*> _unique_sue, //want only unique suespecNode _visited_sue; TREE map<declNode*, declNode*> _unique_field_defn; map<threeAddrNode*,UnifyType*> _ptr_call; unitNode *cur_unit; procNode *cur_proc; bool inside_call_func; bool finalizing, serve_again, new_pending; set<Unify_Pending*> more_pending; Linker &linker; map<declNode*,procNode*> _synthetic_proc; set<procNode*> _analyzed_proc; //, _skip_proc; class findVarAssign; // find number of times a variable is assigned to. map<declNode*,int> _assignments; map<declNode*,bool> _uses; // any use for this var? UnificationBasedPtr(Linker &l) : Walker(Both,Subtree), cur_proc(0), inside_call_func(false), finalizing(false), serve_again(false), new_pending(true), linker(l), _dismantler_tmp(0) {} void at_unit(unitNode *u, Order) { cur_unit = u; } void at_proc(procNode *, Order); void at_decl(declNode *, Order); void at_suespec(suespecNode *, Order); void at_threeAddr(threeAddrNode *, Order); void at_allocation(threeAddrNode *, Unify_Size); void at_call(threeAddrNode *, Unify_Size); void at_initializer(initializerNode *init, typeNode *init_type, Unify_ECR *init_ecr); void mergeOperand(operandNode *lhs, operandNode *rhs, Unify_Size); // condition to use alpha(): operand is addr(). Alpha *alpha(operandNode *, Unify_Size); // condition to use ecr(): opposite of alpha() above. Unify_ECR *ecr(operandNode *, Unify_Size, Unify_Offset **offset=NULL); // similar to ecr(declNode*) but if not found, attempt to create. Unify_ECR *ecr1(declNode *decl); void join(Alpha *a1, Alpha *a2, bool *recursion_detected=NULL); void join(Unify_ECR *e1, Unify_ECR *e2, bool *recursion_detected=NULL); void join(Lambda *l1, Lambda *l2); // new void settype(Unify_ECR *e, UnifyType *t); void settype(Lambda *l, int n, int m, Unify_ECR **t, Unify_ECR *r, bool ellipse); void ensure_sim_obj(Unify_ECR *tao, Unify_Size &s); Unify_Structure *ensure_struct_obj(Unify_ECR *tao, suespecNode *sue, //new bool redo_pending = false); void expand(Unify_ECR *e); void promote(Unify_ECR *e, Unify_Size &s); void collapse(Unify_ECR *e); void make_unknown(Unify_Offset *o); void unless_zero(Unify_Offset *o, Unify_ECR *tao); void cjoin(Unify_Size &s, Unify_ECR *e1, Unify_ECR *e2); UnifyType *unify(UnifyType *t1, UnifyType *t2); bool make_compatible(declSet n, Unify_Structure *s, Unify_ECR *container, bool force=false); void merge_EltMap(/*IN*/ UnifyType *t1, UnifyType *t2, /*IN,OUT*/ Unify_Structure *); void finalize(); static bool is_va_list(declNode * decl); procNode *create_synthetic_proc(declNode *); inline declNode *unique_field_defn(declNode *d) { return _unique_field_defn[d]; } inline suespecNode *field2sue(declNode *d) { return _field2sue[_unique_field_defn[d]]; } // to be overwritten by subclass virtual bool annotation_returns_object(procNode *proc) const { return false; } virtual void annotation_call_arg(procNode*, int arg, typeNode*, Unify_ECR*) {} virtual void annotation_call_arg(procNode*, int arg, typeNode*, Alpha*) {} virtual void annotation_ret_val(procNode *, Unify_ECR *taoR, unitNode *unit){} virtual void annotation_init_global(declNode *global) {} }; // UnificationBasedPtr #define is_Sim_Obj(t) assert(t->objTyp()==SIMPLE || t->objTyp()==OBJECT) #define Sim_Obj_Size(t) (t->objTyp()==SIMPLE ? t->simple()->s : t->object()->s) #define Sim_Obj_Lambda(t) \ (t->objTyp()==SIMPLE ? t->simple()->lambda : t->object()->lambda) #define Sim_Obj_Alpha(t) ((t->objTyp()==SIMPLE) ? t->simple()->alpha : t->object()->alpha) #endif

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