src/doc/rustc-dev-guide/examples/rustc-driver-example.rs

   1 #![feature(rustc_private)]
   2
   3 extern crate rustc;
   4 extern crate rustc_error_codes;
   5 extern crate rustc_errors;
   6 extern crate rustc_hash;
   7 extern crate rustc_hir;
   8 extern crate rustc_interface;
   9 extern crate rustc_span;
  10
  11 use rustc::session;
  12 use rustc::session::config;
  13 use rustc_errors::registry;
  14 use rustc_hash::{FxHashMap, FxHashSet};
  15 use rustc_span::source_map;
  16 use std::path;
  17 use std::process;
  18 use std::str;
  19
  20 fn main() {
  21     let out = process::Command::new("rustc")
  22         .arg("--print=sysroot")
  23         .current_dir(".")
  24         .output()
  25         .unwrap();
  26     let sysroot = str::from_utf8(&out.stdout).unwrap().trim();
  27     let filename = "main.rs";
  28     let contents = "static HELLO: &str = \"Hello, world!\"; fn main() { println!(\"{}\", HELLO); }";
  29     let errors = registry::Registry::new(&rustc_error_codes::DIAGNOSTICS);
  30     let config = rustc_interface::Config {
  31         // Command line options
  32         opts: config::Options {
  33             maybe_sysroot: Some(path::PathBuf::from(sysroot)),
  34             ..config::Options::default()
  35         },
  36
  37         // cfg! configuration in addition to the default ones
  38         // FxHashSet<(String, Option<String>)>
  39         crate_cfg: FxHashSet::default(),
  40
  41         input: config::Input::Str {
  42             name: source_map::FileName::Custom(String::from(filename)),
  43             input: String::from(contents),
  44         },
  45         // Option<PathBuf>
  46         input_path: None,
  47         // Option<PathBuf>
  48         output_dir: None,
  49         // Option<PathBuf>
  50         output_file: None,
  51         // Option<Box<dyn FileLoader + Send + Sync>>
  52         file_loader: None,
  53         diagnostic_output: session::DiagnosticOutput::Default,
  54
  55         // Set to capture stderr output during compiler execution
  56         // Option<Arc<Mutex<Vec<u8>>>>
  57         stderr: None,
  58
  59         // Option<String>
  60         crate_name: None,
  61         // FxHashMap<lint::LintId, lint::Level>
  62         lint_caps: FxHashMap::default(),
  63
  64         // This is a callback from the driver that is called when we're registering lints;
  65         // it is called during plugin registration when we have the LintStore in a non-shared state.
  66         //
  67         // Note that if you find a Some here you probably want to call that function in the new
  68         // function being registered.
  69         // Option<Box<dyn Fn(&Session, &mut LintStore) + Send + Sync>>
  70         register_lints: None,
  71
  72         // This is a callback from the driver that is called just after we have populated
  73         // the list of queries.
  74         //
  75         // The second parameter is local providers and the third parameter is external providers.
  76         // Option<fn(&Session, &mut ty::query::Providers<'_>, &mut ty::query::Providers<'_>)>
  77         override_queries: None,
  78
  79         // Registry of diagnostics codes.
  80         registry: errors,
  81     };
  82     rustc_interface::run_compiler(config, |compiler| {
  83         compiler.enter(|queries| {
  84             // Parse the program and print the syntax tree.
  85             let parse = queries.parse().unwrap().take();
  86             println!("{:#?}", parse);
  87             // Analyze the program and inspect the types of definitions.
  88             queries.global_ctxt().unwrap().take().enter(|tcx| {
  89                 for (_, item) in &tcx.hir().krate().items {
  90                     match item.kind {
  91                         rustc_hir::ItemKind::Static(_, _, _) | rustc_hir::ItemKind::Fn(_, _, _) => {
  92                             let name = item.ident;
  93                             let ty = tcx.type_of(tcx.hir().local_def_id(item.hir_id));
  94                             println!("{:?}:\t{:?}", name, ty)
  95                         }
  96                         _ => (),
  97                     }
  98                 }
  99             })
 100         });
 101     });
 102 }