Files
ngr/src/repl.rs

131 lines
4.4 KiB
Rust

use crate::backend::{Backend, BackendError};
use crate::ir::Program as IR;
use crate::syntax::{Location, ParserError, Statement};
use codespan_reporting::diagnostic::Diagnostic;
use codespan_reporting::files::SimpleFiles;
use codespan_reporting::term::{self, Config};
use cranelift_jit::JITModule;
use cranelift_module::ModuleError;
use pretty::termcolor::{ColorChoice, StandardStream};
use std::collections::HashMap;
pub struct REPL {
file_database: SimpleFiles<String, String>,
jitter: Backend<JITModule>,
variable_binding_sites: HashMap<String, Location>,
gensym_index: usize,
console: StandardStream,
console_config: Config,
}
impl Default for REPL {
fn default() -> Self {
let console = StandardStream::stdout(ColorChoice::Auto);
REPL::new(console, Config::default()).unwrap()
}
}
#[allow(clippy::upper_case_acronyms)]
#[derive(Debug, thiserror::Error)]
enum REPLError {
#[error("Error parsing statement: {0}")]
Parser(#[from] ParserError),
#[error("JIT error: {0}")]
JIT(#[from] BackendError),
#[error("Internal cranelift error: {0}")]
Cranelift(#[from] ModuleError),
#[error(transparent)]
Reporting(#[from] codespan_reporting::files::Error),
}
impl From<REPLError> for Diagnostic<usize> {
fn from(value: REPLError) -> Self {
match value {
REPLError::Parser(err) => Diagnostic::from(&err),
REPLError::JIT(err) => Diagnostic::from(err),
REPLError::Cranelift(err) => Diagnostic::bug().with_message(format!("{}", err)),
REPLError::Reporting(err) => Diagnostic::bug().with_message(format!("{}", err)),
}
}
}
impl REPL {
pub fn new(console: StandardStream, console_config: Config) -> Result<Self, BackendError> {
Ok(REPL {
file_database: SimpleFiles::new(),
jitter: Backend::jit(None)?,
variable_binding_sites: HashMap::new(),
gensym_index: 1,
console,
console_config,
})
}
fn emit_diagnostic(
&mut self,
diagnostic: Diagnostic<usize>,
) -> Result<(), codespan_reporting::files::Error> {
term::emit(
&mut self.console,
&self.console_config,
&self.file_database,
&diagnostic,
)
}
pub fn process_input(&mut self, line_no: usize, command: String) {
if let Err(err) = self.process(line_no, command) {
if let Err(e) = self.emit_diagnostic(Diagnostic::from(err)) {
eprintln!(
"WOAH! System having trouble printing error messages. This is very bad. ({})",
e
);
}
}
}
fn process(&mut self, line_no: usize, command: String) -> Result<(), REPLError> {
let entry = self.file_database.add("entry".to_string(), command);
let source = self
.file_database
.get(entry)
.expect("entry exists")
.source();
let syntax = Statement::parse(entry, source)?;
// if this is a variable binding, and we've never defined this variable before,
// we should tell cranelift about it. this is optimistic; if we fail to compile,
// then we won't use this definition until someone tries again.
if let Statement::Binding(_, ref name, _) = syntax {
if !self.variable_binding_sites.contains_key(name.as_str()) {
self.jitter.define_string(name)?;
self.jitter.define_variable(name.clone())?;
}
};
let (mut errors, mut warnings) = syntax.validate(&mut self.variable_binding_sites);
let stop = !errors.is_empty();
let messages = errors
.drain(..)
.map(Into::into)
.chain(warnings.drain(..).map(Into::into));
for message in messages {
self.emit_diagnostic(message)?;
}
if stop {
return Ok(());
}
let ir = IR::from(syntax.simplify(&mut self.gensym_index));
let name = format!("line{}", line_no);
let function_id = self.jitter.compile_function(&name, ir)?;
self.jitter.module.finalize_definitions()?;
let compiled_bytes = self.jitter.bytes(function_id);
let compiled_function = unsafe { std::mem::transmute::<_, fn() -> ()>(compiled_bytes) };
compiled_function();
Ok(())
}
}