use crate::base::ModuleData; use rustc_ast::ptr::P; use rustc_ast::{token, AttrVec, Attribute, Inline, Item, ModSpans}; use rustc_errors::{struct_span_err, DiagnosticBuilder, ErrorGuaranteed}; use rustc_parse::new_parser_from_file; use rustc_parse::validate_attr; use rustc_session::parse::ParseSess; use rustc_session::Session; use rustc_span::symbol::{sym, Ident}; use rustc_span::Span; use std::path::{self, Path, PathBuf}; #[derive(Copy, Clone)] pub enum DirOwnership { Owned { // None if `mod.rs`, `Some("foo")` if we're in `foo.rs`. relative: Option, }, UnownedViaBlock, } // Public for rustfmt usage. pub struct ModulePathSuccess { pub file_path: PathBuf, pub dir_ownership: DirOwnership, } pub(crate) struct ParsedExternalMod { pub items: Vec>, pub spans: ModSpans, pub file_path: PathBuf, pub dir_path: PathBuf, pub dir_ownership: DirOwnership, } pub enum ModError<'a> { CircularInclusion(Vec), ModInBlock(Option), FileNotFound(Ident, PathBuf, PathBuf), MultipleCandidates(Ident, PathBuf, PathBuf), ParserError(DiagnosticBuilder<'a, ErrorGuaranteed>), } pub(crate) fn parse_external_mod( sess: &Session, ident: Ident, span: Span, // The span to blame on errors. module: &ModuleData, mut dir_ownership: DirOwnership, attrs: &mut AttrVec, ) -> ParsedExternalMod { // We bail on the first error, but that error does not cause a fatal error... (1) let result: Result<_, ModError<'_>> = try { // Extract the file path and the new ownership. let mp = mod_file_path(sess, ident, &attrs, &module.dir_path, dir_ownership)?; dir_ownership = mp.dir_ownership; // Ensure file paths are acyclic. if let Some(pos) = module.file_path_stack.iter().position(|p| p == &mp.file_path) { Err(ModError::CircularInclusion(module.file_path_stack[pos..].to_vec()))?; } // Actually parse the external file as a module. let mut parser = new_parser_from_file(&sess.parse_sess, &mp.file_path, Some(span)); let (inner_attrs, items, inner_span) = parser.parse_mod(&token::Eof).map_err(|err| ModError::ParserError(err))?; attrs.extend(inner_attrs); (items, inner_span, mp.file_path) }; // (1) ...instead, we return a dummy module. let (items, spans, file_path) = result.map_err(|err| err.report(sess, span)).unwrap_or_default(); // Extract the directory path for submodules of the module. let dir_path = file_path.parent().unwrap_or(&file_path).to_owned(); ParsedExternalMod { items, spans, file_path, dir_path, dir_ownership } } pub(crate) fn mod_dir_path( sess: &Session, ident: Ident, attrs: &[Attribute], module: &ModuleData, mut dir_ownership: DirOwnership, inline: Inline, ) -> (PathBuf, DirOwnership) { match inline { Inline::Yes if let Some(file_path) = mod_file_path_from_attr(sess, attrs, &module.dir_path) => { // For inline modules file path from `#[path]` is actually the directory path // for historical reasons, so we don't pop the last segment here. (file_path, DirOwnership::Owned { relative: None }) } Inline::Yes => { // We have to push on the current module name in the case of relative // paths in order to ensure that any additional module paths from inline // `mod x { ... }` come after the relative extension. // // For example, a `mod z { ... }` inside `x/y.rs` should set the current // directory path to `/x/y/z`, not `/x/z` with a relative offset of `y`. let mut dir_path = module.dir_path.clone(); if let DirOwnership::Owned { relative } = &mut dir_ownership { if let Some(ident) = relative.take() { // Remove the relative offset. dir_path.push(ident.as_str()); } } dir_path.push(ident.as_str()); (dir_path, dir_ownership) } Inline::No => { // FIXME: This is a subset of `parse_external_mod` without actual parsing, // check whether the logic for unloaded, loaded and inline modules can be unified. let file_path = mod_file_path(sess, ident, &attrs, &module.dir_path, dir_ownership) .map(|mp| { dir_ownership = mp.dir_ownership; mp.file_path }) .unwrap_or_default(); // Extract the directory path for submodules of the module. let dir_path = file_path.parent().unwrap_or(&file_path).to_owned(); (dir_path, dir_ownership) } } } fn mod_file_path<'a>( sess: &'a Session, ident: Ident, attrs: &[Attribute], dir_path: &Path, dir_ownership: DirOwnership, ) -> Result> { if let Some(file_path) = mod_file_path_from_attr(sess, attrs, dir_path) { // All `#[path]` files are treated as though they are a `mod.rs` file. // This means that `mod foo;` declarations inside `#[path]`-included // files are siblings, // // Note that this will produce weirdness when a file named `foo.rs` is // `#[path]` included and contains a `mod foo;` declaration. // If you encounter this, it's your own darn fault :P let dir_ownership = DirOwnership::Owned { relative: None }; return Ok(ModulePathSuccess { file_path, dir_ownership }); } let relative = match dir_ownership { DirOwnership::Owned { relative } => relative, DirOwnership::UnownedViaBlock => None, }; let result = default_submod_path(&sess.parse_sess, ident, relative, dir_path); match dir_ownership { DirOwnership::Owned { .. } => result, DirOwnership::UnownedViaBlock => Err(ModError::ModInBlock(match result { Ok(_) | Err(ModError::MultipleCandidates(..)) => Some(ident), _ => None, })), } } /// Derive a submodule path from the first found `#[path = "path_string"]`. /// The provided `dir_path` is joined with the `path_string`. fn mod_file_path_from_attr( sess: &Session, attrs: &[Attribute], dir_path: &Path, ) -> Option { // Extract path string from first `#[path = "path_string"]` attribute. let first_path = attrs.iter().find(|at| at.has_name(sym::path))?; let Some(path_sym) = first_path.value_str() else { // This check is here mainly to catch attempting to use a macro, // such as #[path = concat!(...)]. This isn't currently supported // because otherwise the InvocationCollector would need to defer // loading a module until the #[path] attribute was expanded, and // it doesn't support that (and would likely add a bit of // complexity). Usually bad forms are checked in AstValidator (via // `check_builtin_attribute`), but by the time that runs the macro // is expanded, and it doesn't give an error. validate_attr::emit_fatal_malformed_builtin_attribute( &sess.parse_sess, first_path, sym::path, ); }; let path_str = path_sym.as_str(); // On windows, the base path might have the form // `\\?\foo\bar` in which case it does not tolerate // mixed `/` and `\` separators, so canonicalize // `/` to `\`. #[cfg(windows)] let path_str = path_str.replace("/", "\\"); Some(dir_path.join(path_str)) } /// Returns a path to a module. // Public for rustfmt usage. pub fn default_submod_path<'a>( sess: &'a ParseSess, ident: Ident, relative: Option, dir_path: &Path, ) -> Result> { // If we're in a foo.rs file instead of a mod.rs file, // we need to look for submodules in // `./foo/.rs` and `./foo//mod.rs` rather than // `./.rs` and `.//mod.rs`. let relative_prefix_string; let relative_prefix = if let Some(ident) = relative { relative_prefix_string = format!("{}{}", ident.name, path::MAIN_SEPARATOR); &relative_prefix_string } else { "" }; let default_path_str = format!("{}{}.rs", relative_prefix, ident.name); let secondary_path_str = format!("{}{}{}mod.rs", relative_prefix, ident.name, path::MAIN_SEPARATOR); let default_path = dir_path.join(&default_path_str); let secondary_path = dir_path.join(&secondary_path_str); let default_exists = sess.source_map().file_exists(&default_path); let secondary_exists = sess.source_map().file_exists(&secondary_path); match (default_exists, secondary_exists) { (true, false) => Ok(ModulePathSuccess { file_path: default_path, dir_ownership: DirOwnership::Owned { relative: Some(ident) }, }), (false, true) => Ok(ModulePathSuccess { file_path: secondary_path, dir_ownership: DirOwnership::Owned { relative: None }, }), (false, false) => Err(ModError::FileNotFound(ident, default_path, secondary_path)), (true, true) => Err(ModError::MultipleCandidates(ident, default_path, secondary_path)), } } impl ModError<'_> { fn report(self, sess: &Session, span: Span) -> ErrorGuaranteed { let diag = &sess.parse_sess.span_diagnostic; match self { ModError::CircularInclusion(file_paths) => { let mut msg = String::from("circular modules: "); for file_path in &file_paths { msg.push_str(&file_path.display().to_string()); msg.push_str(" -> "); } msg.push_str(&file_paths[0].display().to_string()); diag.struct_span_err(span, &msg) } ModError::ModInBlock(ident) => { let msg = "cannot declare a non-inline module inside a block unless it has a path attribute"; let mut err = diag.struct_span_err(span, msg); if let Some(ident) = ident { let note = format!("maybe `use` the module `{}` instead of redeclaring it", ident); err.span_note(span, ¬e); } err } ModError::FileNotFound(ident, default_path, secondary_path) => { let mut err = struct_span_err!( diag, span, E0583, "file not found for module `{}`", ident, ); err.help(&format!( "to create the module `{}`, create file \"{}\" or \"{}\"", ident, default_path.display(), secondary_path.display(), )); err } ModError::MultipleCandidates(ident, default_path, secondary_path) => { let mut err = struct_span_err!( diag, span, E0761, "file for module `{}` found at both \"{}\" and \"{}\"", ident, default_path.display(), secondary_path.display(), ); err.help("delete or rename one of them to remove the ambiguity"); err } ModError::ParserError(err) => err, }.emit() } }