feat: add better diagnostic rendering

Cargo.lock

@@ -125,6 +125,17 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
 
+[[package]]
+name = "codespan-reporting"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af491d569909a7e4dee0ad7db7f5341fef5c614d5b8ec8cf765732aba3cff681"
+dependencies = [
+ "serde",
+ "termcolor",
+ "unicode-width",
+]
+
 [[package]]
 name = "colorchoice"
 version = "1.0.5"
@@ -136,6 +147,7 @@ name = "compiler"
 version = "0.1.0"
 dependencies = [
  "clap",
+ "codespan-reporting",
  "cranelift-codegen",
  "cranelift-frontend",
  "cranelift-module",
@@ -468,6 +480,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
 dependencies = [
  "serde_core",
+ "serde_derive",
 ]
 
 [[package]]
@@ -525,12 +538,27 @@ version = "0.13.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "adb6935a6f5c20170eeceb1a3835a49e12e19d792f6dd344ccc76a985ca5a6ca"
 
+[[package]]
+name = "termcolor"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06794f8f6c5c898b3275aebefa6b8a1cb24cd2c6c79397ab15774837a0bc5755"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
+[[package]]
+name = "unicode-width"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4ac048d71ede7ee76d585517add45da530660ef4390e49b098733c6e897f254"
+
 [[package]]
 name = "utf8parse"
 version = "0.2.2"
@@ -547,6 +575,15 @@ dependencies = [
  "libm",
 ]
 
+[[package]]
+name = "winapi-util"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
+dependencies = [
+ "windows-sys",
+]
+
 [[package]]
 name = "windows-link"
 version = "0.2.1"

Cargo.toml

@@ -10,3 +10,4 @@ cranelift-frontend = "0.131.0"
 cranelift-module = "0.131.0"
 cranelift-object = "0.131.0"
 cranelift-native = "0.131.0"
+codespan-reporting = "0.13.1"

examples/simple.src

@@ -1,3 +1,7 @@
 fn main() -> i8 {
+    if 2 * 5 == 10 {   
         return -1;
+    } else {
+        return 45;
+    }
 }

src/frontend/token.rs

@@ -1,4 +1,4 @@
-use std::fmt::Display;
+use std::{fmt::Display, ops::Range};
 
 /// A half-open interval `[start, end)` representing a location in the source text.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -23,6 +23,12 @@ impl Span {
     }
 }
 
+impl From<Span> for Range<usize> {
+    fn from(value: Span) -> Self {
+        value.start..value.end
+    }
+}
+
 /// A fundamental, categorized unit of source code produced during lexical analysis.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct Token<'src> {

src/main.rs

@@ -1,12 +1,16 @@
 use std::{fs::read_to_string, path::PathBuf, process::exit};
 
-use clap::Parser as ClapParser;
+use codespan_reporting::diagnostic::{Diagnostic, Label};
+use codespan_reporting::files::SimpleFile;
+use codespan_reporting::term;
+use codespan_reporting::term::termcolor::{ColorChoice, StandardStream};
 
 use crate::frontend::parser::Parser;
 use crate::frontend::sema::Sema;
 use crate::middle::builder::MirBuilder;
 use crate::middle::dce::eliminate_dead_code;
 use crate::middle::fold::fold_constants;
+use clap::Parser as ClapParser;
 
 pub mod backend;
 pub mod frontend;
@@ -37,12 +41,20 @@ fn main() {
         exit(1);
     });
 
+    let writer = StandardStream::stderr(ColorChoice::Always);
+    let config = term::Config::default();
+    let file = SimpleFile::new(&cli.input, &content);
+
     let mut parser = Parser::new(&content);
     let module = parser.parse_module();
 
     if let Some(errors) = parser.errors() {
         for error in errors {
-            eprintln!("{:?}", error);
+            let diagnostic = Diagnostic::error()
+                .with_message(error.message)
+                .with_label(Label::primary((), error.span));
+
+            term::emit_to_write_style(&mut writer.lock(), &config, &file, &diagnostic).unwrap();
         }
 
         exit(1);
@@ -53,7 +65,11 @@ fn main() {
 
     if let Some(errors) = sema.errors() {
         for error in errors {
-            eprintln!("{:?}", error);
+            let diagnostic = Diagnostic::error()
+                .with_message(error.message)
+                .with_label(Label::primary((), error.span));
+
+            term::emit_to_write_style(&mut writer.lock(), &config, &file, &diagnostic).unwrap();
         }
 
         exit(1);
@@ -64,7 +80,11 @@ fn main() {
     let warnings = eliminate_dead_code(&mut mir_module);
 
     for warning in warnings {
-        eprintln!("Warning: {} at {:?}", warning.message, warning.span);
+        let diagnostic = Diagnostic::warning()
+            .with_message(warning.message)
+            .with_label(Label::primary((), warning.span));
+
+        term::emit_to_write_style(&mut writer.lock(), &config, &file, &diagnostic).unwrap();
     }
 
     let backend = CraneliftBackend::new();