512Compiler/semantics.h at master · jssmith1/512Compiler · GitHub

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#include "parsetree.h"
#include <map>

extern int yyparse(void);
extern ParseTree * top;

void openscope();
Symtab *closescope();

struct semantics {
  // pure virtual function:
  virtual string kind() = 0;
  // at least one pure virtual function makes the class abstract
  // (not instantiable.)
  string ident;

};
struct S_class;

struct S_type : public semantics {
  virtual string kind() { return "S_type"; }
  string name; // usually a decaf symbol, but sometimes
  int dimension;
  // campbell's funky idea for types.  FIXME.
  // S_type's name can't be void.
};

struct S_primitive : public semantics {
  virtual string kind() {return "S_primitive"; }
};

struct S_variable : public semantics {
  S_type * type;
  virtual string kind() { return "S_variable"; }
  int sequenceNumber;
  bool formal;
  S_class * parentClass;
};

struct S_function : public semantics {
  virtual string kind() { return "S_function"; }
  vector<S_variable *> formals;
  S_type * returnType;  // NULL for a void function
  bool ctor;
};

struct S_class : public semantics {
  virtual string kind() { return "S_class"; }
  S_class * parentClass;  // extends
  vector<semantics *> fields;  // have to be S_function or S_variable
};

typedef map <string, semantics *> Dictionary;

struct Symtab {
  // A class to represent symbol tables
  // Chained togeher to represent nested scopes.
 public:
  Dictionary dict;
  Symtab(Symtab *p);
  semantics * lookup(string key);
  semantics * local_lookup(string key);

  void insert(string key, semantics * item);

  Symtab * parent;  // outer scope
};