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// Copyright (C) 2019-2023 Aleo Systems Inc.
// This file is part of the Leo library.
// The Leo library is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// The Leo library 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 the Leo library. If not, see <https://www.gnu.org/licenses/>.
use crate::CodeGenerator;
use leo_ast::{functions, Function, Mapping, Mode, Program, ProgramScope, Struct, Type, Variant};
use indexmap::IndexMap;
use itertools::Itertools;
use leo_span::{sym, Symbol};
use std::fmt::Write as _;
impl<'a> CodeGenerator<'a> {
pub(crate) fn visit_program(&mut self, input: &'a Program) -> String {
// Accumulate instructions into a program string.
let mut program_string = String::new();
if !input.imports.is_empty() {
// Visit each import statement and produce a Aleo import instruction.
program_string.push_str(
&input
.imports
.iter()
.map(|(identifier, (imported_program, _))| self.visit_import(identifier, imported_program))
.join("\n"),
);
// Newline separator.
program_string.push('\n');
}
// Retrieve the program scope.
// Note that type checking guarantees that there is exactly one program scope.
let program_scope: &ProgramScope = input.program_scopes.values().next().unwrap();
self.program_id = Some(program_scope.program_id);
// Print the program id.
writeln!(program_string, "program {};", program_scope.program_id)
.expect("Failed to write program id to string.");
// Newline separator.
program_string.push('\n');
// Get the post-order ordering of the composite data types.
// Note that the unwrap is safe since type checking guarantees that the struct dependency graph is acyclic.
let order = self.struct_graph.post_order().unwrap();
// Create a mapping of symbols to references of structs so can perform constant-time lookups.
let structs_map: IndexMap<Symbol, &Struct> =
program_scope.structs.iter().map(|(name, struct_)| (*name, struct_)).collect();
// Visit each `Struct` or `Record` in the post-ordering and produce an Aleo struct or record.
program_string.push_str(
&order
.into_iter()
.map(|name| {
match structs_map.get(&name) {
// If the struct is found, it is a local struct.
Some(struct_) => self.visit_struct_or_record(struct_),
// If the struct is not found, it is an imported struct.
None => String::new(),
}
})
.join("\n"),
);
// Newline separator.
program_string.push('\n');
// Visit each mapping in the Leo AST and produce an Aleo mapping declaration.
program_string
.push_str(&program_scope.mappings.iter().map(|(_, mapping)| self.visit_mapping(mapping)).join("\n"));
// Visit each function in the program scope and produce an Aleo function.
// Note that in the function inlining pass, we reorder the functions such that they are in post-order.
// In other words, a callee function precedes its caller function in the program scope.
program_string.push_str(
&program_scope
.functions
.iter()
.map(|(_, function)| {
// Set the `is_transition_function` flag.
self.is_transition_function = matches!(function.variant, Variant::Transition);
let function_string = self.visit_function(function);
// Unset the `is_transition_function` flag.
self.is_transition_function = false;
function_string
})
.join("\n"),
);
program_string
}
fn visit_import(&mut self, import_name: &'a Symbol, import_program: &'a Program) -> String {
// Load symbols into composite mapping.
let _import_program_string = self.visit_program(import_program);
// todo: We do not need the import program string because we generate instructions for imports separately during leo build.
// Generate string for import statement.
format!("import {import_name}.aleo;")
}
fn visit_struct_or_record(&mut self, struct_: &'a Struct) -> String {
if struct_.is_record { self.visit_record(struct_) } else { self.visit_struct(struct_) }
}
fn visit_struct(&mut self, struct_: &'a Struct) -> String {
// Add private symbol to composite types.
self.composite_mapping.insert(&struct_.identifier.name, (false, String::from("private"))); // todo: private by default here.
let mut output_string = format!("struct {}:\n", struct_.identifier); // todo: check if this is safe from name conflicts.
// Construct and append the record variables.
for var in struct_.members.iter() {
writeln!(output_string, " {} as {};", var.identifier, var.type_,).expect("failed to write to string");
}
output_string
}
fn visit_record(&mut self, record: &'a Struct) -> String {
// Add record symbol to composite types.
let mut output_string = String::from("record");
self.composite_mapping.insert(&record.identifier.name, (true, output_string.clone()));
writeln!(output_string, " {}:", record.identifier).expect("failed to write to string"); // todo: check if this is safe from name conflicts.
// Construct and append the record variables.
for var in record.members.iter() {
let mode = match var.mode {
Mode::Constant => "constant",
Mode::Public => "public",
Mode::None | Mode::Private => "private",
};
writeln!(
output_string,
" {} as {}.{mode};", // todo: CAUTION private record variables only.
var.identifier, var.type_
)
.expect("failed to write to string");
}
output_string
}
fn visit_function(&mut self, function: &'a Function) -> String {
// Initialize the state of `self` with the appropriate values before visiting `function`.
self.next_register = 0;
self.variable_mapping = IndexMap::new();
self.futures.clear();
// TODO: Figure out a better way to initialize.
self.variable_mapping.insert(&sym::SelfLower, "self".to_string());
self.variable_mapping.insert(&sym::block, "block".to_string());
self.current_function = Some(function);
// Construct the header of the function.
// If a function is a program function, generate an Aleo `function`,
// if it is a standard function generate an Aleo `closure`,
// otherwise, it is an inline function, in which case a function should not be generated.
let mut function_string = match function.variant {
Variant::Transition => format!("\nfunction {}:\n", function.identifier),
Variant::Standard => format!("\nclosure {}:\n", function.identifier),
Variant::Inline => return String::from("\n"),
};
// Construct and append the input declarations of the function.
for input in function.input.iter() {
let register_string = format!("r{}", self.next_register);
self.next_register += 1;
let type_string = match input {
functions::Input::Internal(input) => {
self.variable_mapping.insert(&input.identifier.name, register_string.clone());
let visibility = match (self.is_transition_function, input.mode) {
(true, Mode::None) => Mode::Private,
_ => input.mode,
};
self.visit_type_with_visibility(&input.type_, visibility)
}
functions::Input::External(input) => {
self.variable_mapping.insert(&input.identifier.name, register_string.clone());
format!("{}.aleo/{}.record", input.program_name, input.record)
}
};
writeln!(function_string, " input {register_string} as {type_string};",)
.expect("failed to write to string");
}
// Construct and append the function body.
let block_string = self.visit_block(&function.block);
function_string.push_str(&block_string);
// If the finalize block exists, generate the appropriate bytecode.
if let Some(finalize) = &function.finalize {
// Clear the register count.
self.next_register = 0;
self.in_finalize = true;
// Clear the variable mapping.
// TODO: Figure out a better way to initialize.
self.variable_mapping = IndexMap::new();
self.variable_mapping.insert(&sym::SelfLower, "self".to_string());
self.variable_mapping.insert(&sym::block, "block".to_string());
function_string.push_str(&format!("\nfinalize {}:\n", finalize.identifier));
// If the function contained calls that produced futures, then we need to add the futures to the finalize block as input.
// Store the new future registers.
let mut future_registers = Vec::new();
for (_, future_type) in &self.futures {
let register_string = format!("r{}", self.next_register);
writeln!(function_string, " input {register_string} as {future_type};")
.expect("failed to write to string");
future_registers.push(register_string);
self.next_register += 1;
}
// Construct and append the input declarations of the finalize block.
for input in finalize.input.iter() {
let register_string = format!("r{}", self.next_register);
self.next_register += 1;
// TODO: Dedup code.
let type_string = match input {
functions::Input::Internal(input) => {
self.variable_mapping.insert(&input.identifier.name, register_string.clone());
let visibility = match (self.is_transition_function, input.mode) {
(true, Mode::None) => Mode::Public,
_ => input.mode,
};
self.visit_type_with_visibility(&input.type_, visibility)
}
functions::Input::External(input) => {
self.variable_mapping.insert(&input.program_name.name, register_string.clone());
format!("{}.aleo/{}.record", input.program_name, input.record)
}
};
writeln!(function_string, " input {register_string} as {type_string};",)
.expect("failed to write to string");
}
// Invoke `await` on each future.
for register in future_registers {
writeln!(function_string, " await {register};").expect("failed to write to string");
}
// Construct and append the finalize block body.
function_string.push_str(&self.visit_block(&finalize.block));
self.in_finalize = false;
}
function_string
}
fn visit_mapping(&mut self, mapping: &'a Mapping) -> String {
// Create the prefix of the mapping string, e.g. `mapping foo:`.
let mut mapping_string = format!("\nmapping {}:\n", mapping.identifier);
// Helper to construct the string associated with the type.
let create_type = |type_: &Type| {
match type_ {
Type::Mapping(_) | Type::Tuple(_) => unreachable!("Mappings cannot contain mappings or tuples."),
Type::Identifier(identifier) => {
// Lookup the type in the composite mapping.
// Note that this unwrap is safe since all struct and records have been added to the composite mapping.
let (is_record, _) = self.composite_mapping.get(&identifier.name).unwrap();
match is_record {
// If the type is a record, then declare the type as is.
true => format!("{identifier}.record"),
// If the type is a struct, then add the public modifier.
false => format!("{identifier}.public"),
}
}
type_ => format!("{type_}.public"),
}
};
// Create the key string, e.g. ` key as address.public`.
mapping_string.push_str(&format!("\tkey as {};\n", create_type(&mapping.key_type)));
// Create the value string, e.g. ` value as address.public`.
mapping_string.push_str(&format!("\tvalue as {};\n", create_type(&mapping.value_type)));
// Add the mapping to the variable mapping.
self.global_mapping.insert(&mapping.identifier.name, mapping.identifier.to_string());
mapping_string
}
}