1 use super::diagnostics::Error;
2 use super::item::ItemInfo;
5 use crate::{new_sub_parser_from_file, DirectoryOwnership};
7 use rustc_errors::PResult;
8 use syntax::ast::{self, Attribute, Crate, Ident, ItemKind, Mod};
10 use syntax::token::{self, TokenKind};
11 use syntax_pos::source_map::{FileName, SourceMap, Span, DUMMY_SP};
12 use syntax_pos::symbol::sym;
14 use std::path::{self, Path, PathBuf};
16 /// Information about the path to a module.
17 pub(super) struct ModulePath {
20 pub result: Result<ModulePathSuccess, Error>,
23 pub(super) struct ModulePathSuccess {
25 pub directory_ownership: DirectoryOwnership,
29 /// Parses a source module as a crate. This is the main entry point for the parser.
30 pub fn parse_crate_mod(&mut self) -> PResult<'a, Crate> {
31 let lo = self.token.span;
32 let krate = Ok(ast::Crate {
33 attrs: self.parse_inner_attributes()?,
34 module: self.parse_mod_items(&token::Eof, lo)?,
35 span: lo.to(self.token.span),
40 /// Parses a `mod <foo> { ... }` or `mod <foo>;` item.
41 pub(super) fn parse_item_mod(&mut self, outer_attrs: &[Attribute]) -> PResult<'a, ItemInfo> {
42 let (in_cfg, outer_attrs) =
43 crate::config::process_configure_mod(self.sess, self.cfg_mods, outer_attrs);
45 let id_span = self.token.span;
46 let id = self.parse_ident()?;
47 if self.eat(&token::Semi) {
48 if in_cfg && self.recurse_into_file_modules {
49 // This mod is in an external file. Let's go get it!
50 let ModulePathSuccess { path, directory_ownership } =
51 self.submod_path(id, &outer_attrs, id_span)?;
53 self.eval_src_mod(path, directory_ownership, id.to_string(), id_span)?;
54 Ok((id, ItemKind::Mod(module), Some(attrs)))
56 let placeholder = ast::Mod { inner: DUMMY_SP, items: Vec::new(), inline: false };
57 Ok((id, ItemKind::Mod(placeholder), None))
60 let old_directory = self.directory.clone();
61 self.push_directory(id, &outer_attrs);
63 self.expect(&token::OpenDelim(token::Brace))?;
64 let mod_inner_lo = self.token.span;
65 let attrs = self.parse_inner_attributes()?;
66 let module = self.parse_mod_items(&token::CloseDelim(token::Brace), mod_inner_lo)?;
68 self.directory = old_directory;
69 Ok((id, ItemKind::Mod(module), Some(attrs)))
73 /// Given a termination token, parses all of the items in a module.
74 fn parse_mod_items(&mut self, term: &TokenKind, inner_lo: Span) -> PResult<'a, Mod> {
75 let mut items = vec![];
76 while let Some(item) = self.parse_item()? {
78 self.maybe_consume_incorrect_semicolon(&items);
82 let token_str = super::token_descr(&self.token);
83 if !self.maybe_consume_incorrect_semicolon(&items) {
84 let msg = &format!("expected item, found {}", token_str);
85 let mut err = self.struct_span_err(self.token.span, msg);
86 err.span_label(self.token.span, "expected item");
91 let hi = if self.token.span.is_dummy() { inner_lo } else { self.prev_span };
93 Ok(Mod { inner: inner_lo.to(hi), items, inline: true })
99 outer_attrs: &[Attribute],
101 ) -> PResult<'a, ModulePathSuccess> {
102 if let Some(path) = Parser::submod_path_from_attr(outer_attrs, &self.directory.path) {
103 return Ok(ModulePathSuccess {
104 directory_ownership: match path.file_name().and_then(|s| s.to_str()) {
105 // All `#[path]` files are treated as though they are a `mod.rs` file.
106 // This means that `mod foo;` declarations inside `#[path]`-included
107 // files are siblings,
109 // Note that this will produce weirdness when a file named `foo.rs` is
110 // `#[path]` included and contains a `mod foo;` declaration.
111 // If you encounter this, it's your own darn fault :P
112 Some(_) => DirectoryOwnership::Owned { relative: None },
113 _ => DirectoryOwnership::UnownedViaMod,
119 let relative = match self.directory.ownership {
120 DirectoryOwnership::Owned { relative } => relative,
121 DirectoryOwnership::UnownedViaBlock | DirectoryOwnership::UnownedViaMod => None,
124 Parser::default_submod_path(id, relative, &self.directory.path, self.sess.source_map());
126 match self.directory.ownership {
127 DirectoryOwnership::Owned { .. } => {
128 paths.result.map_err(|err| self.span_fatal_err(id_sp, err))
130 DirectoryOwnership::UnownedViaBlock => {
131 let msg = "Cannot declare a non-inline module inside a block \
132 unless it has a path attribute";
133 let mut err = self.struct_span_err(id_sp, msg);
134 if paths.path_exists {
136 "Maybe `use` the module `{}` instead of redeclaring it",
139 err.span_note(id_sp, &msg);
143 DirectoryOwnership::UnownedViaMod => {
145 self.struct_span_err(id_sp, "cannot declare a new module at this location");
146 if !id_sp.is_dummy() {
147 let src_path = self.sess.source_map().span_to_filename(id_sp);
148 if let FileName::Real(src_path) = src_path {
149 if let Some(stem) = src_path.file_stem() {
150 let mut dest_path = src_path.clone();
151 dest_path.set_file_name(stem);
152 dest_path.push("mod.rs");
156 "maybe move this module `{}` to its own \
165 if paths.path_exists {
169 "... or maybe `use` the module `{}` instead \
170 of possibly redeclaring it",
180 pub(super) fn submod_path_from_attr(attrs: &[Attribute], dir_path: &Path) -> Option<PathBuf> {
181 if let Some(s) = attr::first_attr_value_str_by_name(attrs, sym::path) {
184 // On windows, the base path might have the form
185 // `\\?\foo\bar` in which case it does not tolerate
186 // mixed `/` and `\` separators, so canonicalize
189 let s = s.replace("/", "\\");
190 Some(dir_path.join(&*s))
196 /// Returns a path to a module.
197 pub(super) fn default_submod_path(
199 relative: Option<ast::Ident>,
201 source_map: &SourceMap,
203 // If we're in a foo.rs file instead of a mod.rs file,
204 // we need to look for submodules in
205 // `./foo/<id>.rs` and `./foo/<id>/mod.rs` rather than
206 // `./<id>.rs` and `./<id>/mod.rs`.
207 let relative_prefix_string;
208 let relative_prefix = if let Some(ident) = relative {
209 relative_prefix_string = format!("{}{}", ident.name, path::MAIN_SEPARATOR);
210 &relative_prefix_string
215 let mod_name = id.name.to_string();
216 let default_path_str = format!("{}{}.rs", relative_prefix, mod_name);
217 let secondary_path_str =
218 format!("{}{}{}mod.rs", relative_prefix, mod_name, path::MAIN_SEPARATOR);
219 let default_path = dir_path.join(&default_path_str);
220 let secondary_path = dir_path.join(&secondary_path_str);
221 let default_exists = source_map.file_exists(&default_path);
222 let secondary_exists = source_map.file_exists(&secondary_path);
224 let result = match (default_exists, secondary_exists) {
225 (true, false) => Ok(ModulePathSuccess {
227 directory_ownership: DirectoryOwnership::Owned { relative: Some(id) },
229 (false, true) => Ok(ModulePathSuccess {
230 path: secondary_path,
231 directory_ownership: DirectoryOwnership::Owned { relative: None },
233 (false, false) => Err(Error::FileNotFoundForModule {
234 mod_name: mod_name.clone(),
235 default_path: default_path_str,
236 secondary_path: secondary_path_str,
237 dir_path: dir_path.display().to_string(),
239 (true, true) => Err(Error::DuplicatePaths {
240 mod_name: mod_name.clone(),
241 default_path: default_path_str,
242 secondary_path: secondary_path_str,
246 ModulePath { name: mod_name, path_exists: default_exists || secondary_exists, result }
249 /// Reads a module from a source file.
253 directory_ownership: DirectoryOwnership,
256 ) -> PResult<'a, (Mod, Vec<Attribute>)> {
257 let mut included_mod_stack = self.sess.included_mod_stack.borrow_mut();
258 if let Some(i) = included_mod_stack.iter().position(|p| *p == path) {
259 let mut err = String::from("circular modules: ");
260 let len = included_mod_stack.len();
261 for p in &included_mod_stack[i..len] {
262 err.push_str(&p.to_string_lossy());
263 err.push_str(" -> ");
265 err.push_str(&path.to_string_lossy());
266 return Err(self.struct_span_err(id_sp, &err[..]));
268 included_mod_stack.push(path.clone());
269 drop(included_mod_stack);
272 new_sub_parser_from_file(self.sess, &path, directory_ownership, Some(name), id_sp);
273 p0.cfg_mods = self.cfg_mods;
274 let mod_inner_lo = p0.token.span;
275 let mod_attrs = p0.parse_inner_attributes()?;
276 let mut m0 = p0.parse_mod_items(&token::Eof, mod_inner_lo)?;
278 self.sess.included_mod_stack.borrow_mut().pop();
282 fn push_directory(&mut self, id: Ident, attrs: &[Attribute]) {
283 if let Some(path) = attr::first_attr_value_str_by_name(attrs, sym::path) {
284 self.directory.path.to_mut().push(&*path.as_str());
285 self.directory.ownership = DirectoryOwnership::Owned { relative: None };
287 // We have to push on the current module name in the case of relative
288 // paths in order to ensure that any additional module paths from inline
289 // `mod x { ... }` come after the relative extension.
291 // For example, a `mod z { ... }` inside `x/y.rs` should set the current
292 // directory path to `/x/y/z`, not `/x/z` with a relative offset of `y`.
293 if let DirectoryOwnership::Owned { relative } = &mut self.directory.ownership {
294 if let Some(ident) = relative.take() {
295 // remove the relative offset
296 self.directory.path.to_mut().push(&*ident.as_str());
299 self.directory.path.to_mut().push(&*id.as_str());