1 #ifndef IVL_subprogram_H
2 #define IVL_subprogram_H
3 /*
4  * Copyright (c) 2013-2014 Stephen Williams (steve@icarus.com)
5  * Copyright CERN 2013 / Stephen Williams (steve@icarus.com)
6  * Copyright CERN 2015
7  * @author Maciej Suminski (maciej.suminski@cern.ch)
8  *
9  *    This source code is free software; you can redistribute it
10  *    and/or modify it in source code form under the terms of the GNU
11  *    General Public License as published by the Free Software
12  *    Foundation; either version 2 of the License, or (at your option)
13  *    any later version.
14  *
15  *    This program is distributed in the hope that it will be useful,
16  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *    GNU General Public License for more details.
19  *
20  *    You should have received a copy of the GNU General Public License
21  *    along with this program; if not, write to the Free Software
22  *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
23  */
24 
25 # include  "StringHeap.h"
26 # include  "LineInfo.h"
27 # include  "scope.h"
28 # include  <iostream>
29 # include  <list>
30 # include  <cassert>
31 
32 class InterfacePort;
33 class SequentialStmt;
34 class Package;
35 class VType;
36 
37 class SubprogramBody : public LineInfo, public ScopeBase {
38 
39     public:
40       SubprogramBody();
41       ~SubprogramBody();
42 
43       const InterfacePort*find_param(perm_string nam) const;
44 
45       void set_statements(std::list<SequentialStmt*>*statements);
empty_statements()46       inline bool empty_statements() const { return !statements_ || statements_->empty(); }
47 
48       int elaborate();
49       int emit(ostream&out, Entity*ent, ScopeBase*scope);
50 
51 	// Emit body as it would show up in a package.
52       int emit_package(std::ostream&fd);
53 
54       void write_to_stream(std::ostream&fd) const;
55       void dump(std::ostream&fd) const;
56 
header()57       const SubprogramHeader*header() const { return header_; }
is_subprogram()58       bool is_subprogram() const { return true; }
59 
60     private:
61       std::list<SequentialStmt*>*statements_;
62       SubprogramHeader*header_;
63 
64     friend class SubprogramHeader;
65 };
66 
67 class SubprogramHeader : public LineInfo {
68     public:
69       SubprogramHeader(perm_string name, std::list<InterfacePort*>*ports,
70 		 const VType*return_type);
71       virtual ~SubprogramHeader();
72 
73 	// Return true if the specification (name, types, ports)
74 	// matches this subprogram and that subprogram.
75       bool compare_specification(SubprogramHeader*that) const;
76 
param_count()77       int param_count() const { return ports_ ? ports_->size() : 0; }
78       const InterfacePort*find_param(perm_string nam) const;
79       const InterfacePort*peek_param(int idx) const;
80       const VType*peek_param_type(int idx) const;
peek_return_type()81       const VType*peek_return_type() const { return return_type_; }
82 
83 	// Computes the exact return type (e.g. std_logic_vector(7 downto 0)
84 	// instead of generic std_logic_vector)
85       virtual const VType*exact_return_type(const std::vector<Expression*>&, Entity*, ScopeBase*);
86 
set_package(const Package * pkg)87       inline void set_package(const Package*pkg) { assert(!package_); package_ = pkg; }
get_package()88       inline const Package*get_package() const { return package_; }
89 
90 	// Checks if either return type or parameters are unbounded vectors.
91       bool unbounded() const;
92 
93 	// Is the subprogram coming from the standard library?
is_std()94       virtual bool is_std() const { return false; }
95 
body()96       inline SubprogramBody*body() const { return body_; }
97       void set_body(SubprogramBody*bdy);
98 
name()99       inline perm_string name() const { return name_; }
100 
elaborate()101       int elaborate() { return (body_ ? body_->elaborate() : 0); }
102 
103 	// Elaborates an argument basing on the types stored in the subprogram header.
104       int elaborate_argument(Expression*expr, int idx, Entity*ent, ScopeBase*scope);
105 
106 	// Emits the function name, including the package if required.
107       int emit_full_name(const std::vector<Expression*>&argv,
108                          std::ostream&out, Entity*, ScopeBase*) const;
109 
110 	// Function name used in the emission step. The main purpose of this
111 	// method is to handle functions offered by standard VHDL libraries.
112 	// Allows to return different function names depending on the arguments
113 	// (think of size casting or signed/unsigned functions).
114       virtual int emit_name(const std::vector<Expression*>&argv,
115                             std::ostream&out, Entity*, ScopeBase*) const;
116 
117 	// Emit arguments for a specific call. It allows to reorder or skip
118 	// some of the arguments if function signature is different in
119 	// SystemVerilog compared to VHDL.
120       virtual int emit_args(const std::vector<Expression*>&argv,
121                             std::ostream&out, Entity*, ScopeBase*) const;
122 
123 	// Creates a new instance of the function that takes arguments of
124 	// a different type. It is used to allow VHDL functions that work with
125 	// unbounded std_logic_vectors, so there can be a separate instance
126 	// for limited length logic vector.
127       SubprogramHeader*make_instance(std::vector<Expression*> arguments, ScopeBase*scope) const;
128 
129 	// Emit header as it would show up in a package.
130       int emit_package(std::ostream&fd) const;
131 
132       void write_to_stream(std::ostream&fd) const;
133       void dump(std::ostream&fd) const;
134 
135     protected:
136 	// Tries to set the return type to a fixed type. VHDL functions that
137 	// return std_logic_vectors do not specify its length, as SystemVerilog
138 	// demands.
139       void fix_return_type();
140 
141 	// Procedure/function name
142       perm_string name_;
143 
144       std::list<InterfacePort*>*ports_;
145       const VType*return_type_;
146       SubprogramBody*body_;
147       const Package*package_;
148 };
149 
150 // Class to define functions headers defined in the standard VHDL libraries.
151 class SubprogramStdHeader : public SubprogramHeader
152 {
153     public:
SubprogramStdHeader(perm_string nam,std::list<InterfacePort * > * ports,const VType * return_type)154       SubprogramStdHeader(perm_string nam, std::list<InterfacePort*>*ports,
155               const VType*return_type) :
156           SubprogramHeader(nam, ports, return_type) {}
~SubprogramStdHeader()157       virtual ~SubprogramStdHeader() {};
158 
is_std()159       bool is_std() const { return true; }
160 };
161 
162 // The simplest case, when only function name has to be changed.
163 class SubprogramBuiltin : public SubprogramStdHeader
164 {
165     public:
SubprogramBuiltin(perm_string vhdl_name,perm_string sv_name,std::list<InterfacePort * > * ports,const VType * return_type)166       SubprogramBuiltin(perm_string vhdl_name, perm_string sv_name,
167               std::list<InterfacePort*>*ports, const VType*return_type) :
168           SubprogramStdHeader(vhdl_name, ports, return_type), sv_name_(sv_name) {}
~SubprogramBuiltin()169       ~SubprogramBuiltin() {}
170 
171       int emit_name(const std::vector<Expression*>&, std::ostream&out, Entity*, ScopeBase*) const;
172 
173     private:
174 	// SystemVerilog counterpart function name
175       perm_string sv_name_;
176 };
177 
178 // Helper function to print out a human-readable function signature.
179 void emit_subprogram_sig(std::ostream&out, perm_string name,
180         const std::list<const VType*>&arg_types);
181 
182 #endif /* IVL_subprogram_H */
183