1056 lines
40 KiB
Rust
1056 lines
40 KiB
Rust
//! Types for tracking pieces of source code within a crate.
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//!
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//! The [`SourceMap`] tracks all the source code used within a single crate, mapping
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//! from integer byte positions to the original source code location. Each bit
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//! of source parsed during crate parsing (typically files, in-memory strings,
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//! or various bits of macro expansion) cover a continuous range of bytes in the
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//! `SourceMap` and are represented by [`SourceFile`]s. Byte positions are stored in
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//! [`Span`] and used pervasively in the compiler. They are absolute positions
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//! within the `SourceMap`, which upon request can be converted to line and column
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//! information, source code snippets, etc.
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pub use crate::hygiene::{ExpnData, ExpnKind};
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pub use crate::*;
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use rustc_data_structures::fx::FxHashMap;
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use rustc_data_structures::stable_hasher::StableHasher;
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use rustc_data_structures::sync::{AtomicU32, Lrc, MappedReadGuard, ReadGuard, RwLock};
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use std::hash::Hash;
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use std::path::{Path, PathBuf};
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use std::sync::atomic::Ordering;
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use std::{clone::Clone, cmp};
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use std::{convert::TryFrom, unreachable};
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use std::fs;
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use std::io;
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use tracing::debug;
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#[cfg(test)]
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mod tests;
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/// Returns the span itself if it doesn't come from a macro expansion,
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/// otherwise return the call site span up to the `enclosing_sp` by
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/// following the `expn_data` chain.
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pub fn original_sp(sp: Span, enclosing_sp: Span) -> Span {
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let expn_data1 = sp.ctxt().outer_expn_data();
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let expn_data2 = enclosing_sp.ctxt().outer_expn_data();
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if expn_data1.is_root() || !expn_data2.is_root() && expn_data1.call_site == expn_data2.call_site
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{
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sp
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} else {
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original_sp(expn_data1.call_site, enclosing_sp)
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}
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}
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pub mod monotonic {
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use std::ops::{Deref, DerefMut};
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/// A `MonotonicVec` is a `Vec` which can only be grown.
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/// Once inserted, an element can never be removed or swapped,
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/// guaranteeing that any indices into a `MonotonicVec` are stable
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// This is declared in its own module to ensure that the private
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// field is inaccessible
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pub struct MonotonicVec<T>(Vec<T>);
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impl<T> MonotonicVec<T> {
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pub fn new(val: Vec<T>) -> MonotonicVec<T> {
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MonotonicVec(val)
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}
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pub fn push(&mut self, val: T) {
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self.0.push(val);
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}
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}
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impl<T> Default for MonotonicVec<T> {
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fn default() -> Self {
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MonotonicVec::new(vec![])
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}
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}
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impl<T> Deref for MonotonicVec<T> {
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type Target = Vec<T>;
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fn deref(&self) -> &Self::Target {
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&self.0
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}
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}
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impl<T> !DerefMut for MonotonicVec<T> {}
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}
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#[derive(Clone, Encodable, Decodable, Debug, Copy, HashStable_Generic)]
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pub struct Spanned<T> {
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pub node: T,
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pub span: Span,
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}
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pub fn respan<T>(sp: Span, t: T) -> Spanned<T> {
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Spanned { node: t, span: sp }
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}
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pub fn dummy_spanned<T>(t: T) -> Spanned<T> {
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respan(DUMMY_SP, t)
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}
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// _____________________________________________________________________________
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// SourceFile, MultiByteChar, FileName, FileLines
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//
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/// An abstraction over the fs operations used by the Parser.
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pub trait FileLoader {
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/// Query the existence of a file.
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fn file_exists(&self, path: &Path) -> bool;
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/// Read the contents of a UTF-8 file into memory.
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fn read_file(&self, path: &Path) -> io::Result<String>;
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}
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/// A FileLoader that uses std::fs to load real files.
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pub struct RealFileLoader;
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impl FileLoader for RealFileLoader {
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fn file_exists(&self, path: &Path) -> bool {
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path.exists()
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}
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fn read_file(&self, path: &Path) -> io::Result<String> {
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fs::read_to_string(path)
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}
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}
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/// This is a [SourceFile] identifier that is used to correlate source files between
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/// subsequent compilation sessions (which is something we need to do during
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/// incremental compilation).
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///
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/// The [StableSourceFileId] also contains the CrateNum of the crate the source
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/// file was originally parsed for. This way we get two separate entries in
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/// the [SourceMap] if the same file is part of both the local and an upstream
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/// crate. Trying to only have one entry for both cases is problematic because
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/// at the point where we discover that there's a local use of the file in
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/// addition to the upstream one, we might already have made decisions based on
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/// the assumption that it's an upstream file. Treating the two files as
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/// different has no real downsides.
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#[derive(Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable, Debug)]
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pub struct StableSourceFileId {
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// A hash of the source file's FileName. This is hash so that it's size
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// is more predictable than if we included the actual FileName value.
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pub file_name_hash: u64,
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// The CrateNum of the crate this source file was originally parsed for.
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// We cannot include this information in the hash because at the time
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// of hashing we don't have the context to map from the CrateNum's numeric
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// value to a StableCrateId.
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pub cnum: CrateNum,
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}
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// FIXME: we need a more globally consistent approach to the problem solved by
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// StableSourceFileId, perhaps built atop source_file.name_hash.
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impl StableSourceFileId {
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pub fn new(source_file: &SourceFile) -> StableSourceFileId {
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StableSourceFileId::new_from_name(&source_file.name, source_file.cnum)
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}
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fn new_from_name(name: &FileName, cnum: CrateNum) -> StableSourceFileId {
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let mut hasher = StableHasher::new();
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name.hash(&mut hasher);
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StableSourceFileId { file_name_hash: hasher.finish(), cnum }
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}
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}
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// _____________________________________________________________________________
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// SourceMap
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//
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#[derive(Default)]
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pub(super) struct SourceMapFiles {
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source_files: monotonic::MonotonicVec<Lrc<SourceFile>>,
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stable_id_to_source_file: FxHashMap<StableSourceFileId, Lrc<SourceFile>>,
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}
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pub struct SourceMap {
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/// The address space below this value is currently used by the files in the source map.
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used_address_space: AtomicU32,
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files: RwLock<SourceMapFiles>,
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file_loader: Box<dyn FileLoader + Sync + Send>,
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// This is used to apply the file path remapping as specified via
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// `--remap-path-prefix` to all `SourceFile`s allocated within this `SourceMap`.
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path_mapping: FilePathMapping,
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/// The algorithm used for hashing the contents of each source file.
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hash_kind: SourceFileHashAlgorithm,
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}
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impl SourceMap {
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pub fn new(path_mapping: FilePathMapping) -> SourceMap {
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Self::with_file_loader_and_hash_kind(
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Box::new(RealFileLoader),
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path_mapping,
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SourceFileHashAlgorithm::Md5,
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)
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}
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pub fn with_file_loader_and_hash_kind(
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file_loader: Box<dyn FileLoader + Sync + Send>,
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path_mapping: FilePathMapping,
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hash_kind: SourceFileHashAlgorithm,
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) -> SourceMap {
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SourceMap {
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used_address_space: AtomicU32::new(0),
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files: Default::default(),
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file_loader,
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path_mapping,
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hash_kind,
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}
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}
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pub fn path_mapping(&self) -> &FilePathMapping {
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&self.path_mapping
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}
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pub fn file_exists(&self, path: &Path) -> bool {
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self.file_loader.file_exists(path)
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}
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pub fn load_file(&self, path: &Path) -> io::Result<Lrc<SourceFile>> {
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let src = self.file_loader.read_file(path)?;
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let filename = path.to_owned().into();
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Ok(self.new_source_file(filename, src))
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}
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/// Loads source file as a binary blob.
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///
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/// Unlike `load_file`, guarantees that no normalization like BOM-removal
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/// takes place.
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pub fn load_binary_file(&self, path: &Path) -> io::Result<Vec<u8>> {
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// Ideally, this should use `self.file_loader`, but it can't
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// deal with binary files yet.
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let bytes = fs::read(path)?;
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// We need to add file to the `SourceMap`, so that it is present
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// in dep-info. There's also an edge case that file might be both
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// loaded as a binary via `include_bytes!` and as proper `SourceFile`
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// via `mod`, so we try to use real file contents and not just an
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// empty string.
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let text = std::str::from_utf8(&bytes).unwrap_or("").to_string();
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self.new_source_file(path.to_owned().into(), text);
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Ok(bytes)
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}
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// By returning a `MonotonicVec`, we ensure that consumers cannot invalidate
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// any existing indices pointing into `files`.
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pub fn files(&self) -> MappedReadGuard<'_, monotonic::MonotonicVec<Lrc<SourceFile>>> {
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ReadGuard::map(self.files.borrow(), |files| &files.source_files)
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}
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pub fn source_file_by_stable_id(
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&self,
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stable_id: StableSourceFileId,
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) -> Option<Lrc<SourceFile>> {
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self.files.borrow().stable_id_to_source_file.get(&stable_id).cloned()
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}
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fn allocate_address_space(&self, size: usize) -> Result<usize, OffsetOverflowError> {
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let size = u32::try_from(size).map_err(|_| OffsetOverflowError)?;
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loop {
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let current = self.used_address_space.load(Ordering::Relaxed);
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let next = current
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.checked_add(size)
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// Add one so there is some space between files. This lets us distinguish
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// positions in the `SourceMap`, even in the presence of zero-length files.
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.and_then(|next| next.checked_add(1))
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.ok_or(OffsetOverflowError)?;
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if self
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.used_address_space
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.compare_exchange(current, next, Ordering::Relaxed, Ordering::Relaxed)
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.is_ok()
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{
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return Ok(usize::try_from(current).unwrap());
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}
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}
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}
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/// Creates a new `SourceFile`.
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/// If a file already exists in the `SourceMap` with the same ID, that file is returned
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/// unmodified.
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pub fn new_source_file(&self, filename: FileName, src: String) -> Lrc<SourceFile> {
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self.try_new_source_file(filename, src).unwrap_or_else(|OffsetOverflowError| {
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eprintln!("fatal error: rustc does not support files larger than 4GB");
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crate::fatal_error::FatalError.raise()
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})
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}
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fn try_new_source_file(
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&self,
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filename: FileName,
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src: String,
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) -> Result<Lrc<SourceFile>, OffsetOverflowError> {
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// Note that filename may not be a valid path, eg it may be `<anon>` etc,
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// but this is okay because the directory determined by `path.pop()` will
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// be empty, so the working directory will be used.
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let (filename, _) = self.path_mapping.map_filename_prefix(&filename);
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let file_id = StableSourceFileId::new_from_name(&filename, LOCAL_CRATE);
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let lrc_sf = match self.source_file_by_stable_id(file_id) {
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Some(lrc_sf) => lrc_sf,
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None => {
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let start_pos = self.allocate_address_space(src.len())?;
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let source_file = Lrc::new(SourceFile::new(
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filename,
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src,
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Pos::from_usize(start_pos),
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self.hash_kind,
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));
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// Let's make sure the file_id we generated above actually matches
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// the ID we generate for the SourceFile we just created.
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debug_assert_eq!(StableSourceFileId::new(&source_file), file_id);
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let mut files = self.files.borrow_mut();
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files.source_files.push(source_file.clone());
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files.stable_id_to_source_file.insert(file_id, source_file.clone());
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source_file
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}
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};
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Ok(lrc_sf)
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}
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/// Allocates a new `SourceFile` representing a source file from an external
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/// crate. The source code of such an "imported `SourceFile`" is not available,
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/// but we still know enough to generate accurate debuginfo location
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/// information for things inlined from other crates.
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pub fn new_imported_source_file(
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&self,
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filename: FileName,
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src_hash: SourceFileHash,
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name_hash: u128,
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source_len: usize,
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cnum: CrateNum,
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mut file_local_lines: Vec<BytePos>,
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mut file_local_multibyte_chars: Vec<MultiByteChar>,
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mut file_local_non_narrow_chars: Vec<NonNarrowChar>,
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mut file_local_normalized_pos: Vec<NormalizedPos>,
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original_start_pos: BytePos,
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original_end_pos: BytePos,
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) -> Lrc<SourceFile> {
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let start_pos = self
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.allocate_address_space(source_len)
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.expect("not enough address space for imported source file");
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let end_pos = Pos::from_usize(start_pos + source_len);
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let start_pos = Pos::from_usize(start_pos);
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for pos in &mut file_local_lines {
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*pos = *pos + start_pos;
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}
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for mbc in &mut file_local_multibyte_chars {
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mbc.pos = mbc.pos + start_pos;
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}
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for swc in &mut file_local_non_narrow_chars {
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*swc = *swc + start_pos;
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}
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for nc in &mut file_local_normalized_pos {
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nc.pos = nc.pos + start_pos;
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}
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let source_file = Lrc::new(SourceFile {
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name: filename,
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src: None,
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src_hash,
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external_src: Lock::new(ExternalSource::Foreign {
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kind: ExternalSourceKind::AbsentOk,
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original_start_pos,
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original_end_pos,
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}),
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start_pos,
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end_pos,
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lines: file_local_lines,
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multibyte_chars: file_local_multibyte_chars,
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non_narrow_chars: file_local_non_narrow_chars,
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normalized_pos: file_local_normalized_pos,
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name_hash,
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cnum,
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});
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let mut files = self.files.borrow_mut();
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files.source_files.push(source_file.clone());
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files
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.stable_id_to_source_file
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.insert(StableSourceFileId::new(&source_file), source_file.clone());
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source_file
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}
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// If there is a doctest offset, applies it to the line.
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pub fn doctest_offset_line(&self, file: &FileName, orig: usize) -> usize {
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match file {
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FileName::DocTest(_, offset) => {
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if *offset < 0 {
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orig - (-(*offset)) as usize
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} else {
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orig + *offset as usize
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}
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}
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_ => orig,
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}
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}
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/// Return the SourceFile that contains the given `BytePos`
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pub fn lookup_source_file(&self, pos: BytePos) -> Lrc<SourceFile> {
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let idx = self.lookup_source_file_idx(pos);
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(*self.files.borrow().source_files)[idx].clone()
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}
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/// Looks up source information about a `BytePos`.
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pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
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let sf = self.lookup_source_file(pos);
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let (line, col, col_display) = sf.lookup_file_pos_with_col_display(pos);
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Loc { file: sf, line, col, col_display }
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}
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// If the corresponding `SourceFile` is empty, does not return a line number.
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pub fn lookup_line(&self, pos: BytePos) -> Result<SourceFileAndLine, Lrc<SourceFile>> {
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let f = self.lookup_source_file(pos);
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match f.lookup_line(pos) {
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Some(line) => Ok(SourceFileAndLine { sf: f, line }),
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None => Err(f),
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}
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}
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|
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fn span_to_string(&self, sp: Span, prefer_local: bool) -> String {
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if self.files.borrow().source_files.is_empty() || sp.is_dummy() {
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return "no-location".to_string();
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}
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let lo = self.lookup_char_pos(sp.lo());
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let hi = self.lookup_char_pos(sp.hi());
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format!(
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"{}:{}:{}: {}:{}",
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if prefer_local { lo.file.name.prefer_local() } else { lo.file.name.prefer_remapped() },
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lo.line,
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lo.col.to_usize() + 1,
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hi.line,
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hi.col.to_usize() + 1,
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)
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}
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|
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/// Format the span location suitable for embedding in build artifacts
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pub fn span_to_embeddable_string(&self, sp: Span) -> String {
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self.span_to_string(sp, false)
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}
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|
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/// Format the span location to be printed in diagnostics. Must not be emitted
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/// to build artifacts as this may leak local file paths. Use span_to_embeddable_string
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/// for string suitable for embedding.
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pub fn span_to_diagnostic_string(&self, sp: Span) -> String {
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self.span_to_string(sp, true)
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}
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pub fn span_to_filename(&self, sp: Span) -> FileName {
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self.lookup_char_pos(sp.lo()).file.name.clone()
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}
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pub fn is_multiline(&self, sp: Span) -> bool {
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let lo = self.lookup_source_file_idx(sp.lo());
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let hi = self.lookup_source_file_idx(sp.hi());
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if lo != hi {
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return true;
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}
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let f = (*self.files.borrow().source_files)[lo].clone();
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f.lookup_line(sp.lo()) != f.lookup_line(sp.hi())
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}
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|
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pub fn is_valid_span(&self, sp: Span) -> Result<(Loc, Loc), SpanLinesError> {
|
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let lo = self.lookup_char_pos(sp.lo());
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debug!("span_to_lines: lo={:?}", lo);
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let hi = self.lookup_char_pos(sp.hi());
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debug!("span_to_lines: hi={:?}", hi);
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if lo.file.start_pos != hi.file.start_pos {
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return Err(SpanLinesError::DistinctSources(DistinctSources {
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|
begin: (lo.file.name.clone(), lo.file.start_pos),
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end: (hi.file.name.clone(), hi.file.start_pos),
|
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}));
|
|
}
|
|
Ok((lo, hi))
|
|
}
|
|
|
|
pub fn is_line_before_span_empty(&self, sp: Span) -> bool {
|
|
match self.span_to_prev_source(sp) {
|
|
Ok(s) => s.rsplit_once('\n').unwrap_or(("", &s)).1.trim_start().is_empty(),
|
|
Err(_) => false,
|
|
}
|
|
}
|
|
|
|
pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
|
|
debug!("span_to_lines(sp={:?})", sp);
|
|
let (lo, hi) = self.is_valid_span(sp)?;
|
|
assert!(hi.line >= lo.line);
|
|
|
|
if sp.is_dummy() {
|
|
return Ok(FileLines { file: lo.file, lines: Vec::new() });
|
|
}
|
|
|
|
let mut lines = Vec::with_capacity(hi.line - lo.line + 1);
|
|
|
|
// The span starts partway through the first line,
|
|
// but after that it starts from offset 0.
|
|
let mut start_col = lo.col;
|
|
|
|
// For every line but the last, it extends from `start_col`
|
|
// and to the end of the line. Be careful because the line
|
|
// numbers in Loc are 1-based, so we subtract 1 to get 0-based
|
|
// lines.
|
|
//
|
|
// FIXME: now that we handle DUMMY_SP up above, we should consider
|
|
// asserting that the line numbers here are all indeed 1-based.
|
|
let hi_line = hi.line.saturating_sub(1);
|
|
for line_index in lo.line.saturating_sub(1)..hi_line {
|
|
let line_len = lo.file.get_line(line_index).map_or(0, |s| s.chars().count());
|
|
lines.push(LineInfo { line_index, start_col, end_col: CharPos::from_usize(line_len) });
|
|
start_col = CharPos::from_usize(0);
|
|
}
|
|
|
|
// For the last line, it extends from `start_col` to `hi.col`:
|
|
lines.push(LineInfo { line_index: hi_line, start_col, end_col: hi.col });
|
|
|
|
Ok(FileLines { file: lo.file, lines })
|
|
}
|
|
|
|
/// Extracts the source surrounding the given `Span` using the `extract_source` function. The
|
|
/// extract function takes three arguments: a string slice containing the source, an index in
|
|
/// the slice for the beginning of the span and an index in the slice for the end of the span.
|
|
fn span_to_source<F, T>(&self, sp: Span, extract_source: F) -> Result<T, SpanSnippetError>
|
|
where
|
|
F: Fn(&str, usize, usize) -> Result<T, SpanSnippetError>,
|
|
{
|
|
let local_begin = self.lookup_byte_offset(sp.lo());
|
|
let local_end = self.lookup_byte_offset(sp.hi());
|
|
|
|
if local_begin.sf.start_pos != local_end.sf.start_pos {
|
|
Err(SpanSnippetError::DistinctSources(DistinctSources {
|
|
begin: (local_begin.sf.name.clone(), local_begin.sf.start_pos),
|
|
end: (local_end.sf.name.clone(), local_end.sf.start_pos),
|
|
}))
|
|
} else {
|
|
self.ensure_source_file_source_present(local_begin.sf.clone());
|
|
|
|
let start_index = local_begin.pos.to_usize();
|
|
let end_index = local_end.pos.to_usize();
|
|
let source_len = (local_begin.sf.end_pos - local_begin.sf.start_pos).to_usize();
|
|
|
|
if start_index > end_index || end_index > source_len {
|
|
return Err(SpanSnippetError::MalformedForSourcemap(MalformedSourceMapPositions {
|
|
name: local_begin.sf.name.clone(),
|
|
source_len,
|
|
begin_pos: local_begin.pos,
|
|
end_pos: local_end.pos,
|
|
}));
|
|
}
|
|
|
|
if let Some(ref src) = local_begin.sf.src {
|
|
extract_source(src, start_index, end_index)
|
|
} else if let Some(src) = local_begin.sf.external_src.borrow().get_source() {
|
|
extract_source(src, start_index, end_index)
|
|
} else {
|
|
Err(SpanSnippetError::SourceNotAvailable { filename: local_begin.sf.name.clone() })
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Returns the source snippet as `String` corresponding to the given `Span`.
|
|
pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> {
|
|
self.span_to_source(sp, |src, start_index, end_index| {
|
|
src.get(start_index..end_index)
|
|
.map(|s| s.to_string())
|
|
.ok_or(SpanSnippetError::IllFormedSpan(sp))
|
|
})
|
|
}
|
|
|
|
pub fn span_to_margin(&self, sp: Span) -> Option<usize> {
|
|
match self.span_to_prev_source(sp) {
|
|
Err(_) => None,
|
|
Ok(source) => {
|
|
let last_line = source.rsplit_once('\n').unwrap_or(("", &source)).1;
|
|
|
|
Some(last_line.len() - last_line.trim_start().len())
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Returns the source snippet as `String` before the given `Span`.
|
|
pub fn span_to_prev_source(&self, sp: Span) -> Result<String, SpanSnippetError> {
|
|
self.span_to_source(sp, |src, start_index, _| {
|
|
src.get(..start_index).map(|s| s.to_string()).ok_or(SpanSnippetError::IllFormedSpan(sp))
|
|
})
|
|
}
|
|
|
|
/// Extends the given `Span` to just after the previous occurrence of `c`. Return the same span
|
|
/// if no character could be found or if an error occurred while retrieving the code snippet.
|
|
pub fn span_extend_to_prev_char(&self, sp: Span, c: char, accept_newlines: bool) -> Span {
|
|
if let Ok(prev_source) = self.span_to_prev_source(sp) {
|
|
let prev_source = prev_source.rsplit(c).next().unwrap_or("");
|
|
if !prev_source.is_empty() && (accept_newlines || !prev_source.contains('\n')) {
|
|
return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
|
|
}
|
|
}
|
|
|
|
sp
|
|
}
|
|
|
|
/// Extends the given `Span` to just after the previous occurrence of `pat` when surrounded by
|
|
/// whitespace. Returns the same span if no character could be found or if an error occurred
|
|
/// while retrieving the code snippet.
|
|
pub fn span_extend_to_prev_str(&self, sp: Span, pat: &str, accept_newlines: bool) -> Span {
|
|
// assure that the pattern is delimited, to avoid the following
|
|
// fn my_fn()
|
|
// ^^^^ returned span without the check
|
|
// ---------- correct span
|
|
for ws in &[" ", "\t", "\n"] {
|
|
let pat = pat.to_owned() + ws;
|
|
if let Ok(prev_source) = self.span_to_prev_source(sp) {
|
|
let prev_source = prev_source.rsplit(&pat).next().unwrap_or("").trim_start();
|
|
if prev_source.is_empty() && sp.lo().0 != 0 {
|
|
return sp.with_lo(BytePos(sp.lo().0 - 1));
|
|
} else if accept_newlines || !prev_source.contains('\n') {
|
|
return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
|
|
}
|
|
}
|
|
}
|
|
|
|
sp
|
|
}
|
|
|
|
/// Returns the source snippet as `String` after the given `Span`.
|
|
pub fn span_to_next_source(&self, sp: Span) -> Result<String, SpanSnippetError> {
|
|
self.span_to_source(sp, |src, _, end_index| {
|
|
src.get(end_index..).map(|s| s.to_string()).ok_or(SpanSnippetError::IllFormedSpan(sp))
|
|
})
|
|
}
|
|
|
|
/// Extends the given `Span` to just after the next occurrence of `c`.
|
|
pub fn span_extend_to_next_char(&self, sp: Span, c: char, accept_newlines: bool) -> Span {
|
|
if let Ok(next_source) = self.span_to_next_source(sp) {
|
|
let next_source = next_source.split(c).next().unwrap_or("");
|
|
if !next_source.is_empty() && (accept_newlines || !next_source.contains('\n')) {
|
|
return sp.with_hi(BytePos(sp.hi().0 + next_source.len() as u32));
|
|
}
|
|
}
|
|
|
|
sp
|
|
}
|
|
|
|
/// Given a `Span`, tries to get a shorter span ending before the first occurrence of `char`
|
|
/// `c`.
|
|
pub fn span_until_char(&self, sp: Span, c: char) -> Span {
|
|
match self.span_to_snippet(sp) {
|
|
Ok(snippet) => {
|
|
let snippet = snippet.split(c).next().unwrap_or("").trim_end();
|
|
if !snippet.is_empty() && !snippet.contains('\n') {
|
|
sp.with_hi(BytePos(sp.lo().0 + snippet.len() as u32))
|
|
} else {
|
|
sp
|
|
}
|
|
}
|
|
_ => sp,
|
|
}
|
|
}
|
|
|
|
/// Given a `Span`, tries to get a shorter span ending just after the first occurrence of `char`
|
|
/// `c`.
|
|
pub fn span_through_char(&self, sp: Span, c: char) -> Span {
|
|
if let Ok(snippet) = self.span_to_snippet(sp) {
|
|
if let Some(offset) = snippet.find(c) {
|
|
return sp.with_hi(BytePos(sp.lo().0 + (offset + c.len_utf8()) as u32));
|
|
}
|
|
}
|
|
sp
|
|
}
|
|
|
|
/// Given a `Span`, gets a new `Span` covering the first token and all its trailing whitespace
|
|
/// or the original `Span`.
|
|
///
|
|
/// If `sp` points to `"let mut x"`, then a span pointing at `"let "` will be returned.
|
|
pub fn span_until_non_whitespace(&self, sp: Span) -> Span {
|
|
let mut whitespace_found = false;
|
|
|
|
self.span_take_while(sp, |c| {
|
|
if !whitespace_found && c.is_whitespace() {
|
|
whitespace_found = true;
|
|
}
|
|
|
|
!whitespace_found || c.is_whitespace()
|
|
})
|
|
}
|
|
|
|
/// Given a `Span`, gets a new `Span` covering the first token without its trailing whitespace
|
|
/// or the original `Span` in case of error.
|
|
///
|
|
/// If `sp` points to `"let mut x"`, then a span pointing at `"let"` will be returned.
|
|
pub fn span_until_whitespace(&self, sp: Span) -> Span {
|
|
self.span_take_while(sp, |c| !c.is_whitespace())
|
|
}
|
|
|
|
/// Given a `Span`, gets a shorter one until `predicate` yields `false`.
|
|
pub fn span_take_while<P>(&self, sp: Span, predicate: P) -> Span
|
|
where
|
|
P: for<'r> FnMut(&'r char) -> bool,
|
|
{
|
|
if let Ok(snippet) = self.span_to_snippet(sp) {
|
|
let offset = snippet.chars().take_while(predicate).map(|c| c.len_utf8()).sum::<usize>();
|
|
|
|
sp.with_hi(BytePos(sp.lo().0 + (offset as u32)))
|
|
} else {
|
|
sp
|
|
}
|
|
}
|
|
|
|
/// Given a `Span`, return a span ending in the closest `{`. This is useful when you have a
|
|
/// `Span` enclosing a whole item but we need to point at only the head (usually the first
|
|
/// line) of that item.
|
|
///
|
|
/// *Only suitable for diagnostics.*
|
|
pub fn guess_head_span(&self, sp: Span) -> Span {
|
|
// FIXME: extend the AST items to have a head span, or replace callers with pointing at
|
|
// the item's ident when appropriate.
|
|
self.span_until_char(sp, '{')
|
|
}
|
|
|
|
/// Returns a new span representing just the first character of the given span.
|
|
pub fn start_point(&self, sp: Span) -> Span {
|
|
let width = {
|
|
let sp = sp.data();
|
|
let local_begin = self.lookup_byte_offset(sp.lo);
|
|
let start_index = local_begin.pos.to_usize();
|
|
let src = local_begin.sf.external_src.borrow();
|
|
|
|
let snippet = if let Some(ref src) = local_begin.sf.src {
|
|
Some(&src[start_index..])
|
|
} else if let Some(src) = src.get_source() {
|
|
Some(&src[start_index..])
|
|
} else {
|
|
None
|
|
};
|
|
|
|
match snippet {
|
|
None => 1,
|
|
Some(snippet) => match snippet.chars().next() {
|
|
None => 1,
|
|
Some(c) => c.len_utf8(),
|
|
},
|
|
}
|
|
};
|
|
|
|
sp.with_hi(BytePos(sp.lo().0 + width as u32))
|
|
}
|
|
|
|
/// Returns a new span representing just the last character of this span.
|
|
pub fn end_point(&self, sp: Span) -> Span {
|
|
let pos = sp.hi().0;
|
|
|
|
let width = self.find_width_of_character_at_span(sp, false);
|
|
let corrected_end_position = pos.checked_sub(width).unwrap_or(pos);
|
|
|
|
let end_point = BytePos(cmp::max(corrected_end_position, sp.lo().0));
|
|
sp.with_lo(end_point)
|
|
}
|
|
|
|
/// Returns a new span representing the next character after the end-point of this span.
|
|
pub fn next_point(&self, sp: Span) -> Span {
|
|
if sp.is_dummy() {
|
|
return sp;
|
|
}
|
|
let start_of_next_point = sp.hi().0;
|
|
|
|
let width = self.find_width_of_character_at_span(sp.shrink_to_hi(), true);
|
|
// If the width is 1, then the next span should point to the same `lo` and `hi`. However,
|
|
// in the case of a multibyte character, where the width != 1, the next span should
|
|
// span multiple bytes to include the whole character.
|
|
let end_of_next_point =
|
|
start_of_next_point.checked_add(width - 1).unwrap_or(start_of_next_point);
|
|
|
|
let end_of_next_point = BytePos(cmp::max(sp.lo().0 + 1, end_of_next_point));
|
|
Span::new(BytePos(start_of_next_point), end_of_next_point, sp.ctxt())
|
|
}
|
|
|
|
/// Finds the width of the character, either before or after the end of provided span,
|
|
/// depending on the `forwards` parameter.
|
|
fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 {
|
|
let sp = sp.data();
|
|
if sp.lo == sp.hi {
|
|
debug!("find_width_of_character_at_span: early return empty span");
|
|
return 1;
|
|
}
|
|
|
|
let local_begin = self.lookup_byte_offset(sp.lo);
|
|
let local_end = self.lookup_byte_offset(sp.hi);
|
|
debug!(
|
|
"find_width_of_character_at_span: local_begin=`{:?}`, local_end=`{:?}`",
|
|
local_begin, local_end
|
|
);
|
|
|
|
if local_begin.sf.start_pos != local_end.sf.start_pos {
|
|
debug!("find_width_of_character_at_span: begin and end are in different files");
|
|
return 1;
|
|
}
|
|
|
|
let start_index = local_begin.pos.to_usize();
|
|
let end_index = local_end.pos.to_usize();
|
|
debug!(
|
|
"find_width_of_character_at_span: start_index=`{:?}`, end_index=`{:?}`",
|
|
start_index, end_index
|
|
);
|
|
|
|
// Disregard indexes that are at the start or end of their spans, they can't fit bigger
|
|
// characters.
|
|
if (!forwards && end_index == usize::MIN) || (forwards && start_index == usize::MAX) {
|
|
debug!("find_width_of_character_at_span: start or end of span, cannot be multibyte");
|
|
return 1;
|
|
}
|
|
|
|
let source_len = (local_begin.sf.end_pos - local_begin.sf.start_pos).to_usize();
|
|
debug!("find_width_of_character_at_span: source_len=`{:?}`", source_len);
|
|
// Ensure indexes are also not malformed.
|
|
if start_index > end_index || end_index > source_len {
|
|
debug!("find_width_of_character_at_span: source indexes are malformed");
|
|
return 1;
|
|
}
|
|
|
|
let src = local_begin.sf.external_src.borrow();
|
|
|
|
// We need to extend the snippet to the end of the src rather than to end_index so when
|
|
// searching forwards for boundaries we've got somewhere to search.
|
|
let snippet = if let Some(ref src) = local_begin.sf.src {
|
|
&src[start_index..]
|
|
} else if let Some(src) = src.get_source() {
|
|
&src[start_index..]
|
|
} else {
|
|
return 1;
|
|
};
|
|
debug!("find_width_of_character_at_span: snippet=`{:?}`", snippet);
|
|
|
|
let mut target = if forwards { end_index + 1 } else { end_index - 1 };
|
|
debug!("find_width_of_character_at_span: initial target=`{:?}`", target);
|
|
|
|
while !snippet.is_char_boundary(target - start_index) && target < source_len {
|
|
target = if forwards {
|
|
target + 1
|
|
} else {
|
|
match target.checked_sub(1) {
|
|
Some(target) => target,
|
|
None => {
|
|
break;
|
|
}
|
|
}
|
|
};
|
|
debug!("find_width_of_character_at_span: target=`{:?}`", target);
|
|
}
|
|
debug!("find_width_of_character_at_span: final target=`{:?}`", target);
|
|
|
|
if forwards { (target - end_index) as u32 } else { (end_index - target) as u32 }
|
|
}
|
|
|
|
pub fn get_source_file(&self, filename: &FileName) -> Option<Lrc<SourceFile>> {
|
|
// Remap filename before lookup
|
|
let filename = self.path_mapping().map_filename_prefix(filename).0;
|
|
for sf in self.files.borrow().source_files.iter() {
|
|
if filename == sf.name {
|
|
return Some(sf.clone());
|
|
}
|
|
}
|
|
None
|
|
}
|
|
|
|
/// For a global `BytePos`, computes the local offset within the containing `SourceFile`.
|
|
pub fn lookup_byte_offset(&self, bpos: BytePos) -> SourceFileAndBytePos {
|
|
let idx = self.lookup_source_file_idx(bpos);
|
|
let sf = (*self.files.borrow().source_files)[idx].clone();
|
|
let offset = bpos - sf.start_pos;
|
|
SourceFileAndBytePos { sf, pos: offset }
|
|
}
|
|
|
|
// Returns the index of the `SourceFile` (in `self.files`) that contains `pos`.
|
|
// This index is guaranteed to be valid for the lifetime of this `SourceMap`,
|
|
// since `source_files` is a `MonotonicVec`
|
|
pub fn lookup_source_file_idx(&self, pos: BytePos) -> usize {
|
|
self.files
|
|
.borrow()
|
|
.source_files
|
|
.binary_search_by_key(&pos, |key| key.start_pos)
|
|
.unwrap_or_else(|p| p - 1)
|
|
}
|
|
|
|
pub fn count_lines(&self) -> usize {
|
|
self.files().iter().fold(0, |a, f| a + f.count_lines())
|
|
}
|
|
|
|
pub fn generate_fn_name_span(&self, span: Span) -> Option<Span> {
|
|
let prev_span = self.span_extend_to_prev_str(span, "fn", true);
|
|
if let Ok(snippet) = self.span_to_snippet(prev_span) {
|
|
debug!(
|
|
"generate_fn_name_span: span={:?}, prev_span={:?}, snippet={:?}",
|
|
span, prev_span, snippet
|
|
);
|
|
|
|
if snippet.is_empty() {
|
|
return None;
|
|
};
|
|
|
|
let len = snippet
|
|
.find(|c: char| !c.is_alphanumeric() && c != '_')
|
|
.expect("no label after fn");
|
|
Some(prev_span.with_hi(BytePos(prev_span.lo().0 + len as u32)))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Takes the span of a type parameter in a function signature and try to generate a span for
|
|
/// the function name (with generics) and a new snippet for this span with the pointed type
|
|
/// parameter as a new local type parameter.
|
|
///
|
|
/// For instance:
|
|
/// ```rust,ignore (pseudo-Rust)
|
|
/// // Given span
|
|
/// fn my_function(param: T)
|
|
/// // ^ Original span
|
|
///
|
|
/// // Result
|
|
/// fn my_function(param: T)
|
|
/// // ^^^^^^^^^^^ Generated span with snippet `my_function<T>`
|
|
/// ```
|
|
///
|
|
/// Attention: The method used is very fragile since it essentially duplicates the work of the
|
|
/// parser. If you need to use this function or something similar, please consider updating the
|
|
/// `SourceMap` functions and this function to something more robust.
|
|
pub fn generate_local_type_param_snippet(&self, span: Span) -> Option<(Span, String)> {
|
|
// Try to extend the span to the previous "fn" keyword to retrieve the function
|
|
// signature.
|
|
let sugg_span = self.span_extend_to_prev_str(span, "fn", false);
|
|
if sugg_span != span {
|
|
if let Ok(snippet) = self.span_to_snippet(sugg_span) {
|
|
// Consume the function name.
|
|
let mut offset = snippet
|
|
.find(|c: char| !c.is_alphanumeric() && c != '_')
|
|
.expect("no label after fn");
|
|
|
|
// Consume the generics part of the function signature.
|
|
let mut bracket_counter = 0;
|
|
let mut last_char = None;
|
|
for c in snippet[offset..].chars() {
|
|
match c {
|
|
'<' => bracket_counter += 1,
|
|
'>' => bracket_counter -= 1,
|
|
'(' => {
|
|
if bracket_counter == 0 {
|
|
break;
|
|
}
|
|
}
|
|
_ => {}
|
|
}
|
|
offset += c.len_utf8();
|
|
last_char = Some(c);
|
|
}
|
|
|
|
// Adjust the suggestion span to encompass the function name with its generics.
|
|
let sugg_span = sugg_span.with_hi(BytePos(sugg_span.lo().0 + offset as u32));
|
|
|
|
// Prepare the new suggested snippet to append the type parameter that triggered
|
|
// the error in the generics of the function signature.
|
|
let mut new_snippet = if last_char == Some('>') {
|
|
format!("{}, ", &snippet[..(offset - '>'.len_utf8())])
|
|
} else {
|
|
format!("{}<", &snippet[..offset])
|
|
};
|
|
new_snippet
|
|
.push_str(&self.span_to_snippet(span).unwrap_or_else(|_| "T".to_string()));
|
|
new_snippet.push('>');
|
|
|
|
return Some((sugg_span, new_snippet));
|
|
}
|
|
}
|
|
|
|
None
|
|
}
|
|
pub fn ensure_source_file_source_present(&self, source_file: Lrc<SourceFile>) -> bool {
|
|
source_file.add_external_src(|| match source_file.name {
|
|
FileName::Real(ref name) => {
|
|
if let Some(local_path) = name.local_path() {
|
|
self.file_loader.read_file(local_path).ok()
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
_ => None,
|
|
})
|
|
}
|
|
|
|
pub fn is_imported(&self, sp: Span) -> bool {
|
|
let source_file_index = self.lookup_source_file_idx(sp.lo());
|
|
let source_file = &self.files()[source_file_index];
|
|
source_file.is_imported()
|
|
}
|
|
}
|
|
|
|
#[derive(Clone)]
|
|
pub struct FilePathMapping {
|
|
mapping: Vec<(PathBuf, PathBuf)>,
|
|
}
|
|
|
|
impl FilePathMapping {
|
|
pub fn empty() -> FilePathMapping {
|
|
FilePathMapping { mapping: vec![] }
|
|
}
|
|
|
|
pub fn new(mapping: Vec<(PathBuf, PathBuf)>) -> FilePathMapping {
|
|
FilePathMapping { mapping }
|
|
}
|
|
|
|
/// Applies any path prefix substitution as defined by the mapping.
|
|
/// The return value is the remapped path and a boolean indicating whether
|
|
/// the path was affected by the mapping.
|
|
pub fn map_prefix(&self, path: PathBuf) -> (PathBuf, bool) {
|
|
// NOTE: We are iterating over the mapping entries from last to first
|
|
// because entries specified later on the command line should
|
|
// take precedence.
|
|
for &(ref from, ref to) in self.mapping.iter().rev() {
|
|
if let Ok(rest) = path.strip_prefix(from) {
|
|
return (to.join(rest), true);
|
|
}
|
|
}
|
|
|
|
(path, false)
|
|
}
|
|
|
|
fn map_filename_prefix(&self, file: &FileName) -> (FileName, bool) {
|
|
match file {
|
|
FileName::Real(realfile) => {
|
|
if let RealFileName::LocalPath(local_path) = realfile {
|
|
let (mapped_path, mapped) = self.map_prefix(local_path.to_path_buf());
|
|
let realfile = if mapped {
|
|
RealFileName::Remapped {
|
|
local_path: Some(local_path.clone()),
|
|
virtual_name: mapped_path,
|
|
}
|
|
} else {
|
|
realfile.clone()
|
|
};
|
|
(FileName::Real(realfile), mapped)
|
|
} else {
|
|
unreachable!("attempted to remap an already remapped filename");
|
|
}
|
|
}
|
|
other => (other.clone(), false),
|
|
}
|
|
}
|
|
}
|