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iverilog/vhdlpp/expression.h

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#ifndef __expression_H
#define __expression_H
/*
* Copyright (c) 2011 Stephen Williams (steve@icarus.com)
*
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
* General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
# include "StringHeap.h"
# include "LineInfo.h"
# include "entity.h"
# include <inttypes.h>
# include <list>
# include <vector>
class Entity;
class Architecture;
class ScopeBase;
class VType;
class VTypeArray;
class VTypePrimitive;
class ExpName;
/*
* The Expression class represents parsed expressions from the parsed
* VHDL input. The Expression class is a virtual class that holds more
* specific derived expression types.
*/
class Expression : public LineInfo {
public:
Expression();
virtual ~Expression() =0;
// This virtual method handles the special case of elaborating
// an expression that is the l-value of a sequential variable
// assignment. This generates an error for most cases, but
// expressions that are valid l-values return 0 and set any
// flags needed to indicate their status as writable variables.
virtual int elaborate_lval(Entity*ent, Architecture*arc,
bool is_sequ);
// This virtual method probes the expression to get the most
// constrained type for the expression. For a given instance,
// this may be called before the elaborate_expr method.
virtual const VType*probe_type(Entity*ent, Architecture*arc) const;
// This virtual method elaborates an expression. The ltype is
// the type of the lvalue expression, if known, and can be
// used to calculate the type for the expression being
// elaborated.
virtual int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
// Return the type that this expression would be if it were an
// l-value. This should only be called after elaborate_lval is
// called and only if elaborate_lval succeeded.
inline const VType*peek_type(void) const { return type_; }
// The emit virtual method is called by architecture emit to
// output the generated code for the expression. The derived
// class fills in the details of what exactly happened.
virtual int emit(ostream&out, Entity*ent, Architecture*arc) =0;
// The evaluate virtual method tries to evaluate expressions
// to constant literal values. Return true and set the val
// argument if the evaluation works, or return false if it
// cannot be done.
virtual bool evaluate(ScopeBase*scope, int64_t&val) const;
// The symbolic compare returns true if the two expressions
// are equal without actually calculating the value.
virtual bool symbolic_compare(const Expression*that) const;
// This method returns true if the drawn Verilog for this
// expression is a primary. A containing expression can use
// this method to know if it needs to wrap parentheses. This
// is somewhat optional, so it is better to return false if
// not certain. The default implementation does return false.
virtual bool is_primary(void) const;
// Debug dump of the expression.
virtual void dump(ostream&out, int indent = 0) const =0;
protected:
void set_type(const VType*);
private:
const VType*type_;
private: // Not implemented
Expression(const Expression&);
Expression& operator = (const Expression&);
};
static inline void FILE_NAME(Expression*tgt, const LineInfo*src)
{
tgt->set_line(*src);
}
class ExpUnary : public Expression {
public:
ExpUnary(Expression*op1);
virtual ~ExpUnary() =0;
protected:
int emit_operand1(ostream&out, Entity*ent, Architecture*arc);
void dump_operand1(ostream&out, int indent = 0) const;
private:
Expression*operand1_;
};
/*
* This is an abstract class that collects some of the common features
* of binary operators.
*/
class ExpBinary : public Expression {
public:
ExpBinary(Expression*op1, Expression*op2);
virtual ~ExpBinary() =0;
const Expression* peek_operand1(void) const { return operand1_; }
const Expression* peek_operand2(void) const { return operand2_; }
const VType*probe_type(Entity*ent, Architecture*arc) const;
protected:
int elaborate_exprs(Entity*, Architecture*, const VType*);
int emit_operand1(ostream&out, Entity*ent, Architecture*arc);
int emit_operand2(ostream&out, Entity*ent, Architecture*arc);
bool eval_operand1(ScopeBase*scope, int64_t&val) const;
bool eval_operand2(ScopeBase*scope, int64_t&val) const;
void dump_operands(ostream&out, int indent = 0) const;
private:
Expression*operand1_;
Expression*operand2_;
};
class ExpArithmetic : public ExpBinary {
public:
enum fun_t { PLUS, MINUS, MULT, DIV, MOD, REM, POW, CONCAT };
public:
ExpArithmetic(ExpArithmetic::fun_t op, Expression*op1, Expression*op2);
~ExpArithmetic();
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
virtual bool evaluate(ScopeBase*scope, int64_t&val) const;
void dump(ostream&out, int indent = 0) const;
private:
int emit_concat_(ostream&out, Entity*ent, Architecture*arc);
private:
fun_t fun_;
};
class ExpAttribute : public Expression {
public:
ExpAttribute(ExpName*base, perm_string name);
~ExpAttribute();
inline perm_string peek_attribute() const { return name_; }
inline const ExpName* peek_base() const { return base_; }
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
void dump(ostream&out, int indent = 0) const;
private:
ExpName*base_;
perm_string name_;
};
class ExpBitstring : public Expression {
public:
explicit ExpBitstring(const char*);
~ExpBitstring();
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
void dump(ostream&out, int indent = 0) const;
private:
std::vector<char>value_;
};
class ExpCharacter : public Expression {
public:
ExpCharacter(char val);
~ExpCharacter();
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
bool is_primary(void) const;
void dump(ostream&out, int indent = 0) const;
char value() const { return value_; }
private:
int emit_primitive_bit_(ostream&out, Entity*ent, Architecture*arc,
const VTypePrimitive*etype);
private:
char value_;
};
/*
* The conditional expression represents the VHDL when-else
* expressions. Note that by the VHDL syntax rules, these cannot show
* up other then at the root of an expression.
*/
class ExpConditional : public Expression {
public:
ExpConditional(Expression*cond, std::list<Expression*>*tru,
std::list<Expression*>*els);
~ExpConditional();
const VType*probe_type(Entity*ent, Architecture*arc) const;
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
void dump(ostream&out, int indent = 0) const;
private:
Expression*cond_;
std::list<Expression*> true_clause_;
std::list<Expression*> else_clause_;
};
/*
* This is a special expression type that represents posedge/negedge
* expressions in sensitivity lists.
*/
class ExpEdge : public ExpUnary {
public:
enum fun_t { NEGEDGE, ANYEDGE, POSEDGE };
public:
explicit ExpEdge(ExpEdge::fun_t ty, Expression*op);
~ExpEdge();
inline fun_t edge_fun() const { return fun_; }
int emit(ostream&out, Entity*ent, Architecture*arc);
void dump(ostream&out, int indent = 0) const;
private:
fun_t fun_;
};
class ExpFunc : public Expression {
public:
explicit ExpFunc(perm_string nn);
ExpFunc(perm_string nn, Expression*arg);
~ExpFunc();
public: // Base methods
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
void dump(ostream&out, int indent = 0) const;
private:
perm_string name_;
std::vector<Expression*> argv_;
};
class ExpInteger : public Expression {
public:
ExpInteger(int64_t val);
~ExpInteger();
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
bool is_primary(void) const;
bool evaluate(ScopeBase*scope, int64_t&val) const;
void dump(ostream&out, int indent = 0) const;
private:
int64_t value_;
};
class ExpLogical : public ExpBinary {
public:
enum fun_t { AND, OR, NAND, NOR, XOR, XNOR };
public:
ExpLogical(ExpLogical::fun_t ty, Expression*op1, Expression*op2);
~ExpLogical();
inline fun_t logic_fun() const { return fun_; }
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
void dump(ostream&out, int indent = 0) const;
private:
fun_t fun_;
};
/*
* The ExpName class represents an expression that is an identifier or
* other sort of name. The ExpNameALL is a special case of ExpName
* that represents the "all" keyword is contexts that can handle it.
*/
class ExpName : public Expression {
public:
explicit ExpName(perm_string nn);
ExpName(perm_string nn, Expression*index);
ExpName(perm_string nn, Expression*msb, Expression*lsb);
~ExpName();
public: // Base methods
int elaborate_lval(Entity*ent, Architecture*arc, bool);
int elaborate_rval(Entity*ent, Architecture*arc, const InterfacePort*);
const VType* probe_type(Entity*ent, Architecture*arc) const;
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
bool is_primary(void) const;
bool evaluate(ScopeBase*scope, int64_t&val) const;
bool symbolic_compare(const Expression*that) const;
void dump(ostream&out, int indent = 0) const;
const char* name() const;
private:
perm_string name_;
Expression*index_;
Expression*lsb_;
};
class ExpNameALL : public ExpName {
public:
ExpNameALL() : ExpName(perm_string()) { }
public:
int elaborate_lval(Entity*ent, Architecture*arc, bool);
const VType* probe_type(Entity*ent, Architecture*arc) const;
void dump(ostream&out, int indent =0) const;
};
class ExpRelation : public ExpBinary {
public:
enum fun_t { EQ, LT, GT, NEQ, LE, GE };
inline fun_t relation_fun(void) const { return fun_; }
public:
ExpRelation(ExpRelation::fun_t ty, Expression*op1, Expression*op2);
~ExpRelation();
const VType* probe_type(Entity*ent, Architecture*arc) const;
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
void dump(ostream&out, int indent = 0) const;
private:
fun_t fun_;
};
class ExpString : public Expression {
public:
explicit ExpString(const char*);
~ExpString();
int elaborate_expr(Entity*ent, Architecture*arc, const VType*ltype);
int emit(ostream&out, Entity*ent, Architecture*arc);
bool is_primary(void) const;
void dump(ostream&out, int indent = 0) const;
private:
int emit_as_array_(ostream&out, Entity*ent, Architecture*arc, const VTypeArray*arr);
private:
std::vector<char> value_;
};
class ExpUAbs : public ExpUnary {
public:
ExpUAbs(Expression*op1);
~ExpUAbs();
int emit(ostream&out, Entity*ent, Architecture*arc);
void dump(ostream&out, int indent = 0) const;
};
class ExpUNot : public ExpUnary {
public:
ExpUNot(Expression*op1);
~ExpUNot();
int emit(ostream&out, Entity*ent, Architecture*arc);
void dump(ostream&out, int indent = 0) const;
};
#endif
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