neoh 0.1.2

A declarative HDL transpiler for rapid testbench development.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179

/*
 * Copyright 2026 stefand-0
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

use crate::ast::*;
use crate::parser::Rule;
use pest::iterators::{Pair, Pairs};

pub fn build_ast(pairs: Pairs<Rule>) -> File {
    let mut statements = Vec::new();
    for pair in pairs {
        for p in pair.into_inner() {
            match p.as_rule() {
                Rule::block_def => statements.push(Statement::Block(build_block(p))),
                Rule::testbench => statements.push(Statement::Testbench(build_testbench(p))),
                Rule::testgroup => statements.push(Statement::Testgroup(build_testgroup(p))),
                Rule::piece_def => statements.push(Statement::Piece(build_piece(p))),
                _ => (),
            }
        }
    }
    File { statements }
}

fn build_block(pair: Pair<Rule>) -> BlockDef {
    let mut inner = pair.into_inner();
    let name = inner.next().expect("Expected block name").as_str().to_string();
    let mut body = Vec::new();

    for p in inner {
        match p.as_rule() {
            Rule::ret_stmt => body.push(BlockStmt::RetAssign(build_ret_stmt(p))),
            Rule::pass_stmt => body.push(BlockStmt::PassParams(build_pass_stmt(p))),
            Rule::ret_var_stmt => {
                let id = p.into_inner().next()
                    .expect("ret_var_stmt found but identifier missing")
                    .as_str().to_string();
                body.push(BlockStmt::RetVar(id));
            },
            Rule::block_def => body.push(BlockStmt::NestedBlock(build_block(p))),
            _ => (),
        }
    }
    BlockDef { name, params: vec![], body }
}

fn build_ret_stmt(pair: Pair<Rule>) -> RetAssign {
    let nodes: Vec<Pair<Rule>> = pair.into_inner().collect();
    let target = nodes[0].as_str().to_string();
    
    let width = nodes.iter().find(|n| n.as_rule() == Rule::width_constraint)
        .map(|n| parse_width(n.clone()));
    
    let expr = nodes.iter().find(|n| n.as_rule() == Rule::expr)
        .expect("RetStmt expression missing").as_str().to_string();
    
    RetAssign { target, expr, width }
}

fn build_pass_stmt(pair: Pair<Rule>) -> PassParams {
    let mut inner = pair.into_inner();
    let inst_name = inner.next().expect("PassParams inst_name missing").as_str().to_string();
    let block_type = inner.next().expect("PassParams type missing").as_str().to_string();
    let params = inner.map(|p| p.as_str().to_string()).collect();
    PassParams { inst_name, block_type, params }
}

fn build_piece(pair: Pair<Rule>) -> PieceDef {
    let mut inner = pair.into_inner();
    let name = inner.next().expect("Piece name missing").as_str().to_string();
    let members = inner.map(|p| {
        let mut m = p.into_inner();
        (m.next().expect("Member dir missing").as_str().to_string(), m.next().expect("Member name missing").as_str().to_string())
    }).collect();
    PieceDef { name, members }
}

fn build_testbench(pair: Pair<Rule>) -> TestbenchDef {
    let mut inner = pair.into_inner();
    let name = inner.next().expect("TB name missing").as_str().to_string();
    let target = inner.next().expect("TB target missing").as_str().to_string();
    let _getvars = inner.next();
    let when_block = inner.next().expect("TB block missing");

    let mut body = Vec::new();
    for p in when_block.into_inner() {
        body.push(parse_verif_cmd(p));
    }

    TestbenchDef { name, target, body }
}

fn parse_verif_cmd(pair: Pair<Rule>) -> VerifCmd {
    match pair.as_rule() {
        Rule::expect_cmd => {
            let mut i = pair.into_inner();
            VerifCmd::Expect { 
                time: i.next().unwrap().as_str().parse().unwrap(), 
                lhs: i.next().unwrap().as_str().to_string(), 
                rhs: i.next().unwrap().as_str().to_string() 
            }
        },
        Rule::pulse_cmd => {
            let mut i = pair.into_inner();
            VerifCmd::Pulse { 
                len: i.next().unwrap().as_str().to_string(), 
                gap: i.next().unwrap().as_str().to_string() 
            }
        },
        Rule::watch_cmd => {
            let mut i = pair.into_inner();
            let time_a = i.next().unwrap().as_str().parse().unwrap();
            let lhs = i.next().unwrap().as_str().to_string();
            let rhs = i.next().unwrap().as_str().to_string();
            let time_b = i.next().unwrap().as_str().parse().unwrap();
            let out_arg = i.next().unwrap();
            let out = if out_arg.as_rule() == Rule::string_literal {
                OutTarget::Literal(out_arg.as_str().to_string())
            } else {
                OutTarget::Variable(out_arg.as_str().to_string())
            };
            VerifCmd::Watchfor { time_a, lhs, rhs, time_b, out }
        },
        Rule::write_cmd => {
            let mut i = pair.into_inner();
            VerifCmd::Write(WriteStmt { 
                target: i.next().unwrap().as_str().to_string(), 
                val: i.next().unwrap().as_str().to_string() 
            })
        },
        Rule::put_stmt => VerifCmd::Put(build_put(pair)),
        _ => unreachable!(),
    }
}

pub fn build_put(pair: Pair<Rule>) -> PutStmt {
    let nodes: Vec<Pair<Rule>> = pair.into_inner().collect();
    let target = nodes[0].as_str().to_string();
    let op = nodes[1].as_str().to_string();
    
    let width = nodes.iter().find(|n| n.as_rule() == Rule::width_constraint)
        .map(|n| parse_width(n.clone()));
    
    let expr = nodes.iter().find(|n| n.as_rule() == Rule::expr)
        .expect("Put expr missing").as_str().to_string();
        
    PutStmt { target, op, expr, width }
}

fn build_testgroup(pair: Pair<Rule>) -> TestGroupDef {
    let mut inner = pair.into_inner();
    let name = inner.next().expect("TG name missing").as_str().to_string();
    let mut items = Vec::new();
    for p in inner {
        match p.as_rule() {
            Rule::do_stmt => items.push(GroupItem::Do(p.into_inner().next().unwrap().as_str().to_string())),
            Rule::same_block => items.push(GroupItem::Same(p.into_inner().map(|x| x.into_inner().next().unwrap().as_str().to_string()).collect())),
            _ => (),
        }
    }
    TestGroupDef { name, items }
}

fn parse_width(pair: Pair<Rule>) -> WidthConstraint {
    let mut inner = pair.into_inner();
    WidthConstraint { msb: inner.next().unwrap().as_str().parse().unwrap(), lsb: inner.next().unwrap().as_str().parse().unwrap() }
}