2 use super::item::ItemInfo;
3 use super::diagnostics::Error;
5 use crate::{new_sub_parser_from_file, DirectoryOwnership};
7 use rustc_errors::PResult;
9 use syntax::ast::{self, Ident, Attribute, ItemKind, Mod, Crate};
10 use syntax::token::{self, TokenKind};
11 use syntax_pos::source_map::{SourceMap, Span, DUMMY_SP, FileName};
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) = crate::config::process_configure_mod(
48 let id_span = self.token.span;
49 let id = self.parse_ident()?;
50 if self.eat(&token::Semi) {
51 if in_cfg && self.recurse_into_file_modules {
52 // This mod is in an external file. Let's go get it!
53 let ModulePathSuccess { path, directory_ownership } =
54 self.submod_path(id, &outer_attrs, id_span)?;
56 self.eval_src_mod(path, directory_ownership, id.to_string(), id_span)?;
57 Ok((id, ItemKind::Mod(module), Some(attrs)))
59 let placeholder = ast::Mod {
64 Ok((id, ItemKind::Mod(placeholder), None))
67 let old_directory = self.directory.clone();
68 self.push_directory(id, &outer_attrs);
70 self.expect(&token::OpenDelim(token::Brace))?;
71 let mod_inner_lo = self.token.span;
72 let attrs = self.parse_inner_attributes()?;
73 let module = self.parse_mod_items(&token::CloseDelim(token::Brace), mod_inner_lo)?;
75 self.directory = old_directory;
76 Ok((id, ItemKind::Mod(module), Some(attrs)))
80 /// Given a termination token, parses all of the items in a module.
81 fn parse_mod_items(&mut self, term: &TokenKind, inner_lo: Span) -> PResult<'a, Mod> {
82 let mut items = vec![];
83 while let Some(item) = self.parse_item()? {
85 self.maybe_consume_incorrect_semicolon(&items);
89 let token_str = self.this_token_descr();
90 if !self.maybe_consume_incorrect_semicolon(&items) {
91 let mut err = self.fatal(&format!("expected item, found {}", token_str));
92 err.span_label(self.token.span, "expected item");
97 let hi = if self.token.span.is_dummy() {
104 inner: inner_lo.to(hi),
113 outer_attrs: &[Attribute],
115 ) -> PResult<'a, ModulePathSuccess> {
116 if let Some(path) = Parser::submod_path_from_attr(outer_attrs, &self.directory.path) {
117 return Ok(ModulePathSuccess {
118 directory_ownership: match path.file_name().and_then(|s| s.to_str()) {
119 // All `#[path]` files are treated as though they are a `mod.rs` file.
120 // This means that `mod foo;` declarations inside `#[path]`-included
121 // files are siblings,
123 // Note that this will produce weirdness when a file named `foo.rs` is
124 // `#[path]` included and contains a `mod foo;` declaration.
125 // If you encounter this, it's your own darn fault :P
126 Some(_) => DirectoryOwnership::Owned { relative: None },
127 _ => DirectoryOwnership::UnownedViaMod,
133 let relative = match self.directory.ownership {
134 DirectoryOwnership::Owned { relative } => relative,
135 DirectoryOwnership::UnownedViaBlock |
136 DirectoryOwnership::UnownedViaMod => None,
138 let paths = Parser::default_submod_path(
139 id, relative, &self.directory.path, self.sess.source_map());
141 match self.directory.ownership {
142 DirectoryOwnership::Owned { .. } => {
143 paths.result.map_err(|err| self.span_fatal_err(id_sp, err))
145 DirectoryOwnership::UnownedViaBlock => {
147 "Cannot declare a non-inline module inside a block \
148 unless it has a path attribute";
149 let mut err = self.diagnostic().struct_span_err(id_sp, msg);
150 if paths.path_exists {
151 let msg = format!("Maybe `use` the module `{}` instead of redeclaring it",
153 err.span_note(id_sp, &msg);
157 DirectoryOwnership::UnownedViaMod => {
158 let mut err = self.diagnostic().struct_span_err(id_sp,
159 "cannot declare a new module at this location");
160 if !id_sp.is_dummy() {
161 let src_path = self.sess.source_map().span_to_filename(id_sp);
162 if let FileName::Real(src_path) = src_path {
163 if let Some(stem) = src_path.file_stem() {
164 let mut dest_path = src_path.clone();
165 dest_path.set_file_name(stem);
166 dest_path.push("mod.rs");
168 &format!("maybe move this module `{}` to its own \
169 directory via `{}`", src_path.display(),
170 dest_path.display()));
174 if paths.path_exists {
176 &format!("... or maybe `use` the module `{}` instead \
177 of possibly redeclaring it",
185 pub(super) fn submod_path_from_attr(attrs: &[Attribute], dir_path: &Path) -> Option<PathBuf> {
186 if let Some(s) = attr::first_attr_value_str_by_name(attrs, sym::path) {
189 // On windows, the base path might have the form
190 // `\\?\foo\bar` in which case it does not tolerate
191 // mixed `/` and `\` separators, so canonicalize
194 let s = s.replace("/", "\\");
195 Some(dir_path.join(&*s))
201 /// Returns a path to a module.
202 pub(super) fn default_submod_path(
204 relative: Option<ast::Ident>,
206 source_map: &SourceMap) -> ModulePath
208 // If we're in a foo.rs file instead of a mod.rs file,
209 // we need to look for submodules in
210 // `./foo/<id>.rs` and `./foo/<id>/mod.rs` rather than
211 // `./<id>.rs` and `./<id>/mod.rs`.
212 let relative_prefix_string;
213 let relative_prefix = if let Some(ident) = relative {
214 relative_prefix_string = format!("{}{}", ident.name, path::MAIN_SEPARATOR);
215 &relative_prefix_string
220 let mod_name = id.name.to_string();
221 let default_path_str = format!("{}{}.rs", relative_prefix, mod_name);
222 let secondary_path_str = format!("{}{}{}mod.rs",
223 relative_prefix, mod_name, path::MAIN_SEPARATOR);
224 let default_path = dir_path.join(&default_path_str);
225 let secondary_path = dir_path.join(&secondary_path_str);
226 let default_exists = source_map.file_exists(&default_path);
227 let secondary_exists = source_map.file_exists(&secondary_path);
229 let result = match (default_exists, secondary_exists) {
230 (true, false) => Ok(ModulePathSuccess {
232 directory_ownership: DirectoryOwnership::Owned {
236 (false, true) => Ok(ModulePathSuccess {
237 path: secondary_path,
238 directory_ownership: DirectoryOwnership::Owned {
242 (false, false) => Err(Error::FileNotFoundForModule {
243 mod_name: mod_name.clone(),
244 default_path: default_path_str,
245 secondary_path: secondary_path_str,
246 dir_path: dir_path.display().to_string(),
248 (true, true) => Err(Error::DuplicatePaths {
249 mod_name: mod_name.clone(),
250 default_path: default_path_str,
251 secondary_path: secondary_path_str,
257 path_exists: default_exists || secondary_exists,
262 /// Reads a module from a source file.
266 directory_ownership: DirectoryOwnership,
269 ) -> PResult<'a, (Mod, Vec<Attribute>)> {
270 let mut included_mod_stack = self.sess.included_mod_stack.borrow_mut();
271 if let Some(i) = included_mod_stack.iter().position(|p| *p == path) {
272 let mut err = String::from("circular modules: ");
273 let len = included_mod_stack.len();
274 for p in &included_mod_stack[i.. len] {
275 err.push_str(&p.to_string_lossy());
276 err.push_str(" -> ");
278 err.push_str(&path.to_string_lossy());
279 return Err(self.span_fatal(id_sp, &err[..]));
281 included_mod_stack.push(path.clone());
282 drop(included_mod_stack);
285 new_sub_parser_from_file(self.sess, &path, directory_ownership, Some(name), id_sp);
286 p0.cfg_mods = self.cfg_mods;
287 let mod_inner_lo = p0.token.span;
288 let mod_attrs = p0.parse_inner_attributes()?;
289 let mut m0 = p0.parse_mod_items(&token::Eof, mod_inner_lo)?;
291 self.sess.included_mod_stack.borrow_mut().pop();
295 fn push_directory(&mut self, id: Ident, attrs: &[Attribute]) {
296 if let Some(path) = attr::first_attr_value_str_by_name(attrs, sym::path) {
297 self.directory.path.to_mut().push(&*path.as_str());
298 self.directory.ownership = DirectoryOwnership::Owned { relative: None };
300 // We have to push on the current module name in the case of relative
301 // paths in order to ensure that any additional module paths from inline
302 // `mod x { ... }` come after the relative extension.
304 // For example, a `mod z { ... }` inside `x/y.rs` should set the current
305 // directory path to `/x/y/z`, not `/x/z` with a relative offset of `y`.
306 if let DirectoryOwnership::Owned { relative } = &mut self.directory.ownership {
307 if let Some(ident) = relative.take() { // remove the relative offset
308 self.directory.path.to_mut().push(&*ident.as_str());
311 self.directory.path.to_mut().push(&*id.as_str());