snarkvm_synthesizer_program/constructor/
mod.rs

1// Copyright (c) 2019-2025 Provable Inc.
2// This file is part of the snarkVM library.
3
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at:
7
8// http://www.apache.org/licenses/LICENSE-2.0
9
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16mod bytes;
17mod parse;
18
19use crate::Command;
20
21use console::{
22    network::prelude::*,
23    program::{Identifier, Register},
24};
25
26use std::collections::HashMap;
27
28#[derive(Clone, PartialEq, Eq)]
29pub struct ConstructorCore<N: Network> {
30    /// The commands, in order of execution.
31    commands: Vec<Command<N>>,
32    /// The number of write commands.
33    num_writes: u16,
34    /// A mapping from `Position`s to their index in `commands`.
35    positions: HashMap<Identifier<N>, usize>,
36}
37
38impl<N: Network> ConstructorCore<N> {
39    /// Returns the constructor commands.
40    pub fn commands(&self) -> &[Command<N>] {
41        &self.commands
42    }
43
44    /// Returns the number of write commands.
45    pub const fn num_writes(&self) -> u16 {
46        self.num_writes
47    }
48
49    /// Returns the mapping of `Position`s to their index in `commands`.
50    pub const fn positions(&self) -> &HashMap<Identifier<N>, usize> {
51        &self.positions
52    }
53
54    /// Returns `true` if the constructor contains an array type with a size that exceeds the given maximum.
55    pub fn exceeds_max_array_size(&self, max_array_size: u32) -> bool {
56        self.commands.iter().any(|command| {
57            matches!(
58                command,
59                Command::Instruction(instruction) if instruction.exceeds_max_array_size(max_array_size)
60            )
61        })
62    }
63}
64
65impl<N: Network> ConstructorCore<N> {
66    /// Adds the given command to constructor.
67    ///
68    /// # Errors
69    /// This method will halt if the maximum number of commands has been reached.
70    #[inline]
71    pub fn add_command(&mut self, command: Command<N>) -> Result<()> {
72        // Ensure the maximum number of commands has not been exceeded.
73        ensure!(self.commands.len() < N::MAX_COMMANDS, "Cannot add more than {} commands", N::MAX_COMMANDS);
74        // Ensure the number of write commands has not been exceeded.
75        if command.is_write() {
76            ensure!(
77                self.num_writes < N::MAX_WRITES,
78                "Cannot add more than {} 'set' & 'remove' commands",
79                N::MAX_WRITES
80            );
81        }
82
83        // Ensure the command is not an async instruction.
84        ensure!(!command.is_async(), "Forbidden operation: Constructor cannot invoke an 'async' instruction");
85        // Ensure the command is not a call instruction.
86        ensure!(!command.is_call(), "Forbidden operation: Constructor cannot invoke a 'call'");
87        // Ensure the command is not a cast to record instruction.
88        ensure!(!command.is_cast_to_record(), "Forbidden operation: Constructor cannot cast to a record");
89        // Ensure the command is not an await command.
90        ensure!(!command.is_await(), "Forbidden operation: Constructor cannot 'await'");
91
92        // Check the destination registers.
93        for register in command.destinations() {
94            // Ensure the destination register is a locator.
95            ensure!(matches!(register, Register::Locator(..)), "Destination register must be a locator");
96        }
97
98        // Check if the command is a branch command.
99        if let Some(position) = command.branch_to() {
100            // Ensure the branch target does not reference an earlier position.
101            ensure!(!self.positions.contains_key(position), "Cannot branch to an earlier position '{position}'");
102        }
103
104        // Check if the command is a position command.
105        if let Some(position) = command.position() {
106            // Ensure the position is not yet defined.
107            ensure!(!self.positions.contains_key(position), "Cannot redefine position '{position}'");
108            // Ensure that there are less than `u8::MAX` positions.
109            ensure!(self.positions.len() < N::MAX_POSITIONS, "Cannot add more than {} positions", N::MAX_POSITIONS);
110            // Insert the position.
111            self.positions.insert(*position, self.commands.len());
112        }
113
114        // Check if the command is a write command.
115        if command.is_write() {
116            // Increment the number of write commands.
117            self.num_writes += 1;
118        }
119
120        // Insert the command.
121        self.commands.push(command);
122        Ok(())
123    }
124}
125
126impl<N: Network> TypeName for ConstructorCore<N> {
127    /// Returns the type name as a string.
128    #[inline]
129    fn type_name() -> &'static str {
130        "constructor"
131    }
132}
133
134#[cfg(test)]
135mod tests {
136    use super::*;
137
138    use crate::{Command, Constructor};
139
140    type CurrentNetwork = console::network::MainnetV0;
141
142    #[test]
143    fn test_add_command() {
144        // Initialize a new constructor instance.
145        let mut constructor = Constructor::<CurrentNetwork> {
146            commands: Default::default(),
147            num_writes: 0,
148            positions: Default::default(),
149        };
150
151        // Ensure that a command can be added.
152        let command = Command::<CurrentNetwork>::from_str("add r0 r1 into r2;").unwrap();
153        assert!(constructor.add_command(command).is_ok());
154
155        // Ensure that adding more than the maximum number of commands will fail.
156        for i in 3..CurrentNetwork::MAX_COMMANDS * 2 {
157            let command = Command::<CurrentNetwork>::from_str(&format!("add r0 r1 into r{i};")).unwrap();
158
159            match constructor.commands.len() < CurrentNetwork::MAX_COMMANDS {
160                true => assert!(constructor.add_command(command).is_ok()),
161                false => assert!(constructor.add_command(command).is_err()),
162            }
163        }
164
165        // Ensure that adding more than the maximum number of writes will fail.
166
167        // Initialize a new constructor instance.
168        let mut constructor = Constructor::<CurrentNetwork> {
169            commands: Default::default(),
170            num_writes: 0,
171            positions: Default::default(),
172        };
173
174        for _ in 0..CurrentNetwork::MAX_WRITES * 2 {
175            let command = Command::<CurrentNetwork>::from_str("remove object[r0];").unwrap();
176
177            match constructor.commands.len() < CurrentNetwork::MAX_WRITES as usize {
178                true => assert!(constructor.add_command(command).is_ok()),
179                false => assert!(constructor.add_command(command).is_err()),
180            }
181        }
182    }
183
184    #[test]
185    fn test_add_command_duplicate_positions() {
186        // Initialize a new constructor instance.
187        let mut constructor =
188            Constructor { commands: Default::default(), num_writes: 0, positions: Default::default() };
189
190        // Ensure that a command can be added.
191        let command = Command::<CurrentNetwork>::from_str("position start;").unwrap();
192        assert!(constructor.add_command(command.clone()).is_ok());
193
194        // Ensure that adding a duplicate position will fail.
195        assert!(constructor.add_command(command).is_err());
196
197        // Helper method to convert a number to a unique string.
198        #[allow(clippy::cast_possible_truncation)]
199        fn to_unique_string(mut n: usize) -> String {
200            let mut s = String::new();
201            while n > 0 {
202                s.push((b'A' + (n % 26) as u8) as char);
203                n /= 26;
204            }
205            s.chars().rev().collect::<String>()
206        }
207
208        // Ensure that adding more than the maximum number of positions will fail.
209        for i in 1..u8::MAX as usize * 2 {
210            let position = to_unique_string(i);
211            println!("position: {position}");
212            let command = Command::<CurrentNetwork>::from_str(&format!("position {position};")).unwrap();
213
214            match constructor.commands.len() < u8::MAX as usize {
215                true => assert!(constructor.add_command(command).is_ok()),
216                false => assert!(constructor.add_command(command).is_err()),
217            }
218        }
219    }
220}
snarkvm_synthesizer_program/constructor/mod.rs

snarkvm_synthesizer_program/constructor/
mod.rs
