rust/src/libsyntax/codemap.rs

1279 lines
46 KiB
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! The CodeMap tracks all the source code used within a single crate, mapping
//! from integer byte positions to the original source code location. Each bit
//! of source parsed during crate parsing (typically files, in-memory strings,
//! or various bits of macro expansion) cover a continuous range of bytes in the
//! CodeMap and are represented by FileMaps. Byte positions are stored in
//! `spans` and used pervasively in the compiler. They are absolute positions
//! within the CodeMap, which upon request can be converted to line and column
//! information, source code snippets, etc.
pub use self::ExpnFormat::*;
use std::cell::RefCell;
use std::path::{Path,PathBuf};
use std::rc::Rc;
use std::env;
use std::fs;
use std::io::{self, Read};
pub use syntax_pos::*;
use errors::CodeMapper;
use ast::Name;
/// Return the span itself if it doesn't come from a macro expansion,
/// otherwise return the call site span up to the `enclosing_sp` by
/// following the `expn_info` chain.
pub fn original_sp(cm: &CodeMap, sp: Span, enclosing_sp: Span) -> Span {
let call_site1 = cm.with_expn_info(sp.expn_id, |ei| ei.map(|ei| ei.call_site));
let call_site2 = cm.with_expn_info(enclosing_sp.expn_id, |ei| ei.map(|ei| ei.call_site));
match (call_site1, call_site2) {
(None, _) => sp,
(Some(call_site1), Some(call_site2)) if call_site1 == call_site2 => sp,
(Some(call_site1), _) => original_sp(cm, call_site1, enclosing_sp),
}
}
/// The source of expansion.
#[derive(Clone, Hash, Debug, PartialEq, Eq)]
pub enum ExpnFormat {
/// e.g. #[derive(...)] <item>
MacroAttribute(Name),
/// e.g. `format!()`
MacroBang(Name),
/// Desugaring done by the compiler during HIR lowering.
CompilerDesugaring(Name)
}
#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
pub struct Spanned<T> {
pub node: T,
pub span: Span,
}
pub fn spanned<T>(lo: BytePos, hi: BytePos, t: T) -> Spanned<T> {
respan(mk_sp(lo, hi), t)
}
pub fn respan<T>(sp: Span, t: T) -> Spanned<T> {
Spanned {node: t, span: sp}
}
pub fn dummy_spanned<T>(t: T) -> Spanned<T> {
respan(DUMMY_SP, t)
}
/// Build a span that covers the two provided spans.
pub fn combine_spans(sp1: Span, sp2: Span) -> Span {
if sp1 == DUMMY_SP && sp2 == DUMMY_SP {
DUMMY_SP
} else if sp1 == DUMMY_SP {
sp2
} else if sp2 == DUMMY_SP {
sp1
} else {
Span {
lo: if sp1.lo < sp2.lo { sp1.lo } else { sp2.lo },
hi: if sp1.hi > sp2.hi { sp1.hi } else { sp2.hi },
expn_id: if sp1.expn_id == sp2.expn_id { sp1.expn_id } else { NO_EXPANSION },
}
}
}
#[derive(Clone, Hash, Debug)]
pub struct NameAndSpan {
/// The format with which the macro was invoked.
pub format: ExpnFormat,
/// Whether the macro is allowed to use #[unstable]/feature-gated
/// features internally without forcing the whole crate to opt-in
/// to them.
pub allow_internal_unstable: bool,
/// The span of the macro definition itself. The macro may not
/// have a sensible definition span (e.g. something defined
/// completely inside libsyntax) in which case this is None.
pub span: Option<Span>
}
impl NameAndSpan {
pub fn name(&self) -> Name {
match self.format {
ExpnFormat::MacroAttribute(s) |
ExpnFormat::MacroBang(s) |
ExpnFormat::CompilerDesugaring(s) => s,
}
}
}
/// Extra information for tracking spans of macro and syntax sugar expansion
#[derive(Hash, Debug)]
pub struct ExpnInfo {
/// The location of the actual macro invocation or syntax sugar , e.g.
/// `let x = foo!();` or `if let Some(y) = x {}`
///
/// This may recursively refer to other macro invocations, e.g. if
/// `foo!()` invoked `bar!()` internally, and there was an
/// expression inside `bar!`; the call_site of the expression in
/// the expansion would point to the `bar!` invocation; that
/// call_site span would have its own ExpnInfo, with the call_site
/// pointing to the `foo!` invocation.
pub call_site: Span,
/// Information about the expansion.
pub callee: NameAndSpan
}
// _____________________________________________________________________________
// FileMap, MultiByteChar, FileName, FileLines
//
/// An abstraction over the fs operations used by the Parser.
pub trait FileLoader {
/// Query the existence of a file.
fn file_exists(&self, path: &Path) -> bool;
/// Return an absolute path to a file, if possible.
fn abs_path(&self, path: &Path) -> Option<PathBuf>;
/// Read the contents of an UTF-8 file into memory.
fn read_file(&self, path: &Path) -> io::Result<String>;
}
/// A FileLoader that uses std::fs to load real files.
pub struct RealFileLoader;
impl FileLoader for RealFileLoader {
fn file_exists(&self, path: &Path) -> bool {
fs::metadata(path).is_ok()
}
fn abs_path(&self, path: &Path) -> Option<PathBuf> {
if path.is_absolute() {
Some(path.to_path_buf())
} else {
env::current_dir()
.ok()
.map(|cwd| cwd.join(path))
}
}
fn read_file(&self, path: &Path) -> io::Result<String> {
let mut src = String::new();
fs::File::open(path)?.read_to_string(&mut src)?;
Ok(src)
}
}
// _____________________________________________________________________________
// CodeMap
//
pub struct CodeMap {
pub files: RefCell<Vec<Rc<FileMap>>>,
expansions: RefCell<Vec<ExpnInfo>>,
file_loader: Box<FileLoader>
}
impl CodeMap {
pub fn new() -> CodeMap {
CodeMap {
files: RefCell::new(Vec::new()),
expansions: RefCell::new(Vec::new()),
file_loader: Box::new(RealFileLoader)
}
}
pub fn with_file_loader(file_loader: Box<FileLoader>) -> CodeMap {
CodeMap {
files: RefCell::new(Vec::new()),
expansions: RefCell::new(Vec::new()),
file_loader: file_loader
}
}
pub fn file_exists(&self, path: &Path) -> bool {
self.file_loader.file_exists(path)
}
pub fn load_file(&self, path: &Path) -> io::Result<Rc<FileMap>> {
let src = self.file_loader.read_file(path)?;
let abs_path = self.file_loader.abs_path(path).map(|p| p.to_str().unwrap().to_string());
Ok(self.new_filemap(path.to_str().unwrap().to_string(), abs_path, src))
}
fn next_start_pos(&self) -> usize {
let files = self.files.borrow();
match files.last() {
None => 0,
// Add one so there is some space between files. This lets us distinguish
// positions in the codemap, even in the presence of zero-length files.
Some(last) => last.end_pos.to_usize() + 1,
}
}
/// Creates a new filemap without setting its line information. If you don't
/// intend to set the line information yourself, you should use new_filemap_and_lines.
pub fn new_filemap(&self, filename: FileName, abs_path: Option<FileName>,
mut src: String) -> Rc<FileMap> {
let start_pos = self.next_start_pos();
let mut files = self.files.borrow_mut();
// Remove utf-8 BOM if any.
if src.starts_with("\u{feff}") {
src.drain(..3);
}
let end_pos = start_pos + src.len();
let filemap = Rc::new(FileMap {
name: filename,
abs_path: abs_path,
src: Some(Rc::new(src)),
start_pos: Pos::from_usize(start_pos),
end_pos: Pos::from_usize(end_pos),
lines: RefCell::new(Vec::new()),
multibyte_chars: RefCell::new(Vec::new()),
});
files.push(filemap.clone());
filemap
}
/// Creates a new filemap and sets its line information.
pub fn new_filemap_and_lines(&self, filename: &str, abs_path: Option<&str>,
src: &str) -> Rc<FileMap> {
let fm = self.new_filemap(filename.to_string(),
abs_path.map(|s| s.to_owned()),
src.to_owned());
let mut byte_pos: u32 = fm.start_pos.0;
for line in src.lines() {
// register the start of this line
fm.next_line(BytePos(byte_pos));
// update byte_pos to include this line and the \n at the end
byte_pos += line.len() as u32 + 1;
}
fm
}
/// Allocates a new FileMap representing a source file from an external
/// crate. The source code of such an "imported filemap" is not available,
/// but we still know enough to generate accurate debuginfo location
/// information for things inlined from other crates.
pub fn new_imported_filemap(&self,
filename: FileName,
abs_path: Option<FileName>,
source_len: usize,
mut file_local_lines: Vec<BytePos>,
mut file_local_multibyte_chars: Vec<MultiByteChar>)
-> Rc<FileMap> {
let start_pos = self.next_start_pos();
let mut files = self.files.borrow_mut();
let end_pos = Pos::from_usize(start_pos + source_len);
let start_pos = Pos::from_usize(start_pos);
for pos in &mut file_local_lines {
*pos = *pos + start_pos;
}
for mbc in &mut file_local_multibyte_chars {
mbc.pos = mbc.pos + start_pos;
}
let filemap = Rc::new(FileMap {
name: filename,
abs_path: abs_path,
src: None,
start_pos: start_pos,
end_pos: end_pos,
lines: RefCell::new(file_local_lines),
multibyte_chars: RefCell::new(file_local_multibyte_chars),
});
files.push(filemap.clone());
filemap
}
pub fn mk_substr_filename(&self, sp: Span) -> String {
let pos = self.lookup_char_pos(sp.lo);
(format!("<{}:{}:{}>",
pos.file.name,
pos.line,
pos.col.to_usize() + 1)).to_string()
}
/// Lookup source information about a BytePos
pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
let chpos = self.bytepos_to_file_charpos(pos);
match self.lookup_line(pos) {
Ok(FileMapAndLine { fm: f, line: a }) => {
let line = a + 1; // Line numbers start at 1
let linebpos = (*f.lines.borrow())[a];
let linechpos = self.bytepos_to_file_charpos(linebpos);
debug!("byte pos {:?} is on the line at byte pos {:?}",
pos, linebpos);
debug!("char pos {:?} is on the line at char pos {:?}",
chpos, linechpos);
debug!("byte is on line: {}", line);
assert!(chpos >= linechpos);
Loc {
file: f,
line: line,
col: chpos - linechpos,
}
}
Err(f) => {
Loc {
file: f,
line: 0,
col: chpos,
}
}
}
}
// If the relevant filemap is empty, we don't return a line number.
fn lookup_line(&self, pos: BytePos) -> Result<FileMapAndLine, Rc<FileMap>> {
let idx = self.lookup_filemap_idx(pos);
let files = self.files.borrow();
let f = (*files)[idx].clone();
match f.lookup_line(pos) {
Some(line) => Ok(FileMapAndLine { fm: f, line: line }),
None => Err(f)
}
}
pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt {
let loc = self.lookup_char_pos(pos);
LocWithOpt {
filename: loc.file.name.to_string(),
line: loc.line,
col: loc.col,
file: Some(loc.file)
}
}
/// Returns `Some(span)`, a union of the lhs and rhs span. The lhs must precede the rhs. If
/// there are gaps between lhs and rhs, the resulting union will cross these gaps.
/// For this to work, the spans have to be:
/// * the expn_id of both spans much match
/// * the lhs span needs to end on the same line the rhs span begins
/// * the lhs span must start at or before the rhs span
pub fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
use std::cmp;
// make sure we're at the same expansion id
if sp_lhs.expn_id != sp_rhs.expn_id {
return None;
}
let lhs_end = match self.lookup_line(sp_lhs.hi) {
Ok(x) => x,
Err(_) => return None
};
let rhs_begin = match self.lookup_line(sp_rhs.lo) {
Ok(x) => x,
Err(_) => return None
};
// if we must cross lines to merge, don't merge
if lhs_end.line != rhs_begin.line {
return None;
}
// ensure these follow the expected order and we don't overlap
if (sp_lhs.lo <= sp_rhs.lo) && (sp_lhs.hi <= sp_rhs.lo) {
Some(Span {
lo: cmp::min(sp_lhs.lo, sp_rhs.lo),
hi: cmp::max(sp_lhs.hi, sp_rhs.hi),
expn_id: sp_lhs.expn_id,
})
} else {
None
}
}
pub fn span_to_string(&self, sp: Span) -> String {
if sp == COMMAND_LINE_SP {
return "<command line option>".to_string();
}
if self.files.borrow().is_empty() && sp.source_equal(&DUMMY_SP) {
return "no-location".to_string();
}
let lo = self.lookup_char_pos_adj(sp.lo);
let hi = self.lookup_char_pos_adj(sp.hi);
return (format!("{}:{}:{}: {}:{}",
lo.filename,
lo.line,
lo.col.to_usize() + 1,
hi.line,
hi.col.to_usize() + 1)).to_string()
}
// Returns true if two spans have the same callee
// (Assumes the same ExpnFormat implies same callee)
fn match_callees(&self, sp_a: &Span, sp_b: &Span) -> bool {
let fmt_a = self
.with_expn_info(sp_a.expn_id,
|ei| ei.map(|ei| ei.callee.format.clone()));
let fmt_b = self
.with_expn_info(sp_b.expn_id,
|ei| ei.map(|ei| ei.callee.format.clone()));
fmt_a == fmt_b
}
/// Returns a formatted string showing the expansion chain of a span
///
/// Spans are printed in the following format:
///
/// filename:start_line:col: end_line:col
/// snippet
/// Callee:
/// Callee span
/// Callsite:
/// Callsite span
///
/// Callees and callsites are printed recursively (if available, otherwise header
/// and span is omitted), expanding into their own callee/callsite spans.
/// Each layer of recursion has an increased indent, and snippets are truncated
/// to at most 50 characters. Finally, recursive calls to the same macro are squashed,
/// with '...' used to represent any number of recursive calls.
pub fn span_to_expanded_string(&self, sp: Span) -> String {
self.span_to_expanded_string_internal(sp, "")
}
fn span_to_expanded_string_internal(&self, sp:Span, indent: &str) -> String {
let mut indent = indent.to_owned();
let mut output = "".to_owned();
let span_str = self.span_to_string(sp);
let mut span_snip = self.span_to_snippet(sp)
.unwrap_or("Snippet unavailable".to_owned());
// Truncate by code points - in worst case this will be more than 50 characters,
// but ensures at least 50 characters and respects byte boundaries.
let char_vec: Vec<(usize, char)> = span_snip.char_indices().collect();
if char_vec.len() > 50 {
span_snip.truncate(char_vec[49].0);
span_snip.push_str("...");
}
output.push_str(&format!("{}{}\n{}`{}`\n", indent, span_str, indent, span_snip));
if sp.expn_id == NO_EXPANSION || sp.expn_id == COMMAND_LINE_EXPN {
return output;
}
let mut callee = self.with_expn_info(sp.expn_id,
|ei| ei.and_then(|ei| ei.callee.span.clone()));
let mut callsite = self.with_expn_info(sp.expn_id,
|ei| ei.map(|ei| ei.call_site.clone()));
indent.push_str(" ");
let mut is_recursive = false;
while callee.is_some() && self.match_callees(&sp, &callee.unwrap()) {
callee = self.with_expn_info(callee.unwrap().expn_id,
|ei| ei.and_then(|ei| ei.callee.span.clone()));
is_recursive = true;
}
if let Some(span) = callee {
output.push_str(&indent);
output.push_str("Callee:\n");
if is_recursive {
output.push_str(&indent);
output.push_str("...\n");
}
output.push_str(&(self.span_to_expanded_string_internal(span, &indent)));
}
is_recursive = false;
while callsite.is_some() && self.match_callees(&sp, &callsite.unwrap()) {
callsite = self.with_expn_info(callsite.unwrap().expn_id,
|ei| ei.map(|ei| ei.call_site.clone()));
is_recursive = true;
}
if let Some(span) = callsite {
output.push_str(&indent);
output.push_str("Callsite:\n");
if is_recursive {
output.push_str(&indent);
output.push_str("...\n");
}
output.push_str(&(self.span_to_expanded_string_internal(span, &indent)));
}
output
}
/// Return the source span - this is either the supplied span, or the span for
/// the macro callsite that expanded to it.
pub fn source_callsite(&self, sp: Span) -> Span {
let mut span = sp;
// Special case - if a macro is parsed as an argument to another macro, the source
// callsite is the first callsite, which is also source-equivalent to the span.
let mut first = true;
while span.expn_id != NO_EXPANSION && span.expn_id != COMMAND_LINE_EXPN {
if let Some(callsite) = self.with_expn_info(span.expn_id,
|ei| ei.map(|ei| ei.call_site.clone())) {
if first && span.source_equal(&callsite) {
if self.lookup_char_pos(span.lo).file.is_real_file() {
return Span { expn_id: NO_EXPANSION, .. span };
}
}
first = false;
span = callsite;
}
else {
break;
}
}
span
}
/// Return the source callee.
///
/// Returns None if the supplied span has no expansion trace,
/// else returns the NameAndSpan for the macro definition
/// corresponding to the source callsite.
pub fn source_callee(&self, sp: Span) -> Option<NameAndSpan> {
let mut span = sp;
// Special case - if a macro is parsed as an argument to another macro, the source
// callsite is source-equivalent to the span, and the source callee is the first callee.
let mut first = true;
while let Some(callsite) = self.with_expn_info(span.expn_id,
|ei| ei.map(|ei| ei.call_site.clone())) {
if first && span.source_equal(&callsite) {
if self.lookup_char_pos(span.lo).file.is_real_file() {
return self.with_expn_info(span.expn_id,
|ei| ei.map(|ei| ei.callee.clone()));
}
}
first = false;
if let Some(_) = self.with_expn_info(callsite.expn_id,
|ei| ei.map(|ei| ei.call_site.clone())) {
span = callsite;
}
else {
return self.with_expn_info(span.expn_id,
|ei| ei.map(|ei| ei.callee.clone()));
}
}
None
}
pub fn span_to_filename(&self, sp: Span) -> FileName {
self.lookup_char_pos(sp.lo).file.name.to_string()
}
pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
debug!("span_to_lines(sp={:?})", sp);
if sp.lo > sp.hi {
return Err(SpanLinesError::IllFormedSpan(sp));
}
let lo = self.lookup_char_pos(sp.lo);
debug!("span_to_lines: lo={:?}", lo);
let hi = self.lookup_char_pos(sp.hi);
debug!("span_to_lines: hi={:?}", hi);
if lo.file.start_pos != hi.file.start_pos {
return Err(SpanLinesError::DistinctSources(DistinctSources {
begin: (lo.file.name.clone(), lo.file.start_pos),
end: (hi.file.name.clone(), hi.file.start_pos),
}));
}
assert!(hi.line >= lo.line);
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.
for line_index in lo.line-1 .. hi.line-1 {
let line_len = lo.file.get_line(line_index)
.map(|s| s.chars().count())
.unwrap_or(0);
lines.push(LineInfo { line_index: line_index,
start_col: 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 - 1,
start_col: start_col,
end_col: hi.col });
Ok(FileLines {file: lo.file, lines: lines})
}
pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> {
if sp.lo > sp.hi {
return Err(SpanSnippetError::IllFormedSpan(sp));
}
let local_begin = self.lookup_byte_offset(sp.lo);
let local_end = self.lookup_byte_offset(sp.hi);
if local_begin.fm.start_pos != local_end.fm.start_pos {
return Err(SpanSnippetError::DistinctSources(DistinctSources {
begin: (local_begin.fm.name.clone(),
local_begin.fm.start_pos),
end: (local_end.fm.name.clone(),
local_end.fm.start_pos)
}));
} else {
match local_begin.fm.src {
Some(ref src) => {
let start_index = local_begin.pos.to_usize();
let end_index = local_end.pos.to_usize();
let source_len = (local_begin.fm.end_pos -
local_begin.fm.start_pos).to_usize();
if start_index > end_index || end_index > source_len {
return Err(SpanSnippetError::MalformedForCodemap(
MalformedCodemapPositions {
name: local_begin.fm.name.clone(),
source_len: source_len,
begin_pos: local_begin.pos,
end_pos: local_end.pos,
}));
}
return Ok((&src[start_index..end_index]).to_string())
}
None => {
return Err(SpanSnippetError::SourceNotAvailable {
filename: local_begin.fm.name.clone()
});
}
}
}
}
pub fn get_filemap(&self, filename: &str) -> Option<Rc<FileMap>> {
for fm in self.files.borrow().iter() {
if filename == fm.name {
return Some(fm.clone());
}
}
None
}
/// For a global BytePos compute the local offset within the containing FileMap
pub fn lookup_byte_offset(&self, bpos: BytePos) -> FileMapAndBytePos {
let idx = self.lookup_filemap_idx(bpos);
let fm = (*self.files.borrow())[idx].clone();
let offset = bpos - fm.start_pos;
FileMapAndBytePos {fm: fm, pos: offset}
}
/// Converts an absolute BytePos to a CharPos relative to the filemap.
pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos {
let idx = self.lookup_filemap_idx(bpos);
let files = self.files.borrow();
let map = &(*files)[idx];
// The number of extra bytes due to multibyte chars in the FileMap
let mut total_extra_bytes = 0;
for mbc in map.multibyte_chars.borrow().iter() {
debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos);
if mbc.pos < bpos {
// every character is at least one byte, so we only
// count the actual extra bytes.
total_extra_bytes += mbc.bytes - 1;
// We should never see a byte position in the middle of a
// character
assert!(bpos.to_usize() >= mbc.pos.to_usize() + mbc.bytes);
} else {
break;
}
}
assert!(map.start_pos.to_usize() + total_extra_bytes <= bpos.to_usize());
CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes)
}
// Return the index of the filemap (in self.files) which contains pos.
pub fn lookup_filemap_idx(&self, pos: BytePos) -> usize {
let files = self.files.borrow();
let files = &*files;
let count = files.len();
// Binary search for the filemap.
let mut a = 0;
let mut b = count;
while b - a > 1 {
let m = (a + b) / 2;
if files[m].start_pos > pos {
b = m;
} else {
a = m;
}
}
assert!(a < count, "position {} does not resolve to a source location", pos.to_usize());
return a;
}
pub fn record_expansion(&self, expn_info: ExpnInfo) -> ExpnId {
let mut expansions = self.expansions.borrow_mut();
expansions.push(expn_info);
let len = expansions.len();
if len > u32::max_value() as usize {
panic!("too many ExpnInfo's!");
}
ExpnId(len as u32 - 1)
}
pub fn with_expn_info<T, F>(&self, id: ExpnId, f: F) -> T where
F: FnOnce(Option<&ExpnInfo>) -> T,
{
match id {
NO_EXPANSION | COMMAND_LINE_EXPN => f(None),
ExpnId(i) => f(Some(&(*self.expansions.borrow())[i as usize]))
}
}
/// Check if a span is "internal" to a macro in which #[unstable]
/// items can be used (that is, a macro marked with
/// `#[allow_internal_unstable]`).
pub fn span_allows_unstable(&self, span: Span) -> bool {
debug!("span_allows_unstable(span = {:?})", span);
let mut allows_unstable = false;
let mut expn_id = span.expn_id;
loop {
let quit = self.with_expn_info(expn_id, |expninfo| {
debug!("span_allows_unstable: expninfo = {:?}", expninfo);
expninfo.map_or(/* hit the top level */ true, |info| {
let span_comes_from_this_expansion =
info.callee.span.map_or(span.source_equal(&info.call_site), |mac_span| {
mac_span.contains(span)
});
debug!("span_allows_unstable: span: {:?} call_site: {:?} callee: {:?}",
(span.lo, span.hi),
(info.call_site.lo, info.call_site.hi),
info.callee.span.map(|x| (x.lo, x.hi)));
debug!("span_allows_unstable: from this expansion? {}, allows unstable? {}",
span_comes_from_this_expansion,
info.callee.allow_internal_unstable);
if span_comes_from_this_expansion {
allows_unstable = info.callee.allow_internal_unstable;
// we've found the right place, stop looking
true
} else {
// not the right place, keep looking
expn_id = info.call_site.expn_id;
false
}
})
});
if quit {
break
}
}
debug!("span_allows_unstable? {}", allows_unstable);
allows_unstable
}
pub fn count_lines(&self) -> usize {
self.files.borrow().iter().fold(0, |a, f| a + f.count_lines())
}
pub fn macro_backtrace(&self, span: Span) -> Vec<MacroBacktrace> {
let mut prev_span = DUMMY_SP;
let mut span = span;
let mut result = vec![];
loop {
let span_name_span = self.with_expn_info(span.expn_id, |expn_info| {
expn_info.map(|ei| {
let (pre, post) = match ei.callee.format {
MacroAttribute(..) => ("#[", "]"),
MacroBang(..) => ("", "!"),
CompilerDesugaring(..) => ("desugaring of `", "`"),
};
let macro_decl_name = format!("{}{}{}",
pre,
ei.callee.name(),
post);
let def_site_span = ei.callee.span;
(ei.call_site, macro_decl_name, def_site_span)
})
});
match span_name_span {
None => break,
Some((call_site, macro_decl_name, def_site_span)) => {
// Don't print recursive invocations
if !call_site.source_equal(&prev_span) {
result.push(MacroBacktrace {
call_site: call_site,
macro_decl_name: macro_decl_name,
def_site_span: def_site_span,
});
}
prev_span = span;
span = call_site;
}
}
}
result
}
}
impl CodeMapper for CodeMap {
fn lookup_char_pos(&self, pos: BytePos) -> Loc {
self.lookup_char_pos(pos)
}
fn span_to_lines(&self, sp: Span) -> FileLinesResult {
self.span_to_lines(sp)
}
fn span_to_string(&self, sp: Span) -> String {
self.span_to_string(sp)
}
fn span_to_filename(&self, sp: Span) -> FileName {
self.span_to_filename(sp)
}
fn macro_backtrace(&self, span: Span) -> Vec<MacroBacktrace> {
self.macro_backtrace(span)
}
fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
self.merge_spans(sp_lhs, sp_rhs)
}
}
// _____________________________________________________________________________
// Tests
//
#[cfg(test)]
mod tests {
use super::*;
use symbol::keywords;
use std::rc::Rc;
#[test]
fn t1 () {
let cm = CodeMap::new();
let fm = cm.new_filemap("blork.rs".to_string(),
None,
"first line.\nsecond line".to_string());
fm.next_line(BytePos(0));
// Test we can get lines with partial line info.
assert_eq!(fm.get_line(0), Some("first line."));
// TESTING BROKEN BEHAVIOR: line break declared before actual line break.
fm.next_line(BytePos(10));
assert_eq!(fm.get_line(1), Some("."));
fm.next_line(BytePos(12));
assert_eq!(fm.get_line(2), Some("second line"));
}
#[test]
#[should_panic]
fn t2 () {
let cm = CodeMap::new();
let fm = cm.new_filemap("blork.rs".to_string(),
None,
"first line.\nsecond line".to_string());
// TESTING *REALLY* BROKEN BEHAVIOR:
fm.next_line(BytePos(0));
fm.next_line(BytePos(10));
fm.next_line(BytePos(2));
}
fn init_code_map() -> CodeMap {
let cm = CodeMap::new();
let fm1 = cm.new_filemap("blork.rs".to_string(),
None,
"first line.\nsecond line".to_string());
let fm2 = cm.new_filemap("empty.rs".to_string(),
None,
"".to_string());
let fm3 = cm.new_filemap("blork2.rs".to_string(),
None,
"first line.\nsecond line".to_string());
fm1.next_line(BytePos(0));
fm1.next_line(BytePos(12));
fm2.next_line(fm2.start_pos);
fm3.next_line(fm3.start_pos);
fm3.next_line(fm3.start_pos + BytePos(12));
cm
}
#[test]
fn t3() {
// Test lookup_byte_offset
let cm = init_code_map();
let fmabp1 = cm.lookup_byte_offset(BytePos(23));
assert_eq!(fmabp1.fm.name, "blork.rs");
assert_eq!(fmabp1.pos, BytePos(23));
let fmabp1 = cm.lookup_byte_offset(BytePos(24));
assert_eq!(fmabp1.fm.name, "empty.rs");
assert_eq!(fmabp1.pos, BytePos(0));
let fmabp2 = cm.lookup_byte_offset(BytePos(25));
assert_eq!(fmabp2.fm.name, "blork2.rs");
assert_eq!(fmabp2.pos, BytePos(0));
}
#[test]
fn t4() {
// Test bytepos_to_file_charpos
let cm = init_code_map();
let cp1 = cm.bytepos_to_file_charpos(BytePos(22));
assert_eq!(cp1, CharPos(22));
let cp2 = cm.bytepos_to_file_charpos(BytePos(25));
assert_eq!(cp2, CharPos(0));
}
#[test]
fn t5() {
// Test zero-length filemaps.
let cm = init_code_map();
let loc1 = cm.lookup_char_pos(BytePos(22));
assert_eq!(loc1.file.name, "blork.rs");
assert_eq!(loc1.line, 2);
assert_eq!(loc1.col, CharPos(10));
let loc2 = cm.lookup_char_pos(BytePos(25));
assert_eq!(loc2.file.name, "blork2.rs");
assert_eq!(loc2.line, 1);
assert_eq!(loc2.col, CharPos(0));
}
fn init_code_map_mbc() -> CodeMap {
let cm = CodeMap::new();
// € is a three byte utf8 char.
let fm1 =
cm.new_filemap("blork.rs".to_string(),
None,
"fir€st €€€€ line.\nsecond line".to_string());
let fm2 = cm.new_filemap("blork2.rs".to_string(),
None,
"first line€€.\n€ second line".to_string());
fm1.next_line(BytePos(0));
fm1.next_line(BytePos(28));
fm2.next_line(fm2.start_pos);
fm2.next_line(fm2.start_pos + BytePos(20));
fm1.record_multibyte_char(BytePos(3), 3);
fm1.record_multibyte_char(BytePos(9), 3);
fm1.record_multibyte_char(BytePos(12), 3);
fm1.record_multibyte_char(BytePos(15), 3);
fm1.record_multibyte_char(BytePos(18), 3);
fm2.record_multibyte_char(fm2.start_pos + BytePos(10), 3);
fm2.record_multibyte_char(fm2.start_pos + BytePos(13), 3);
fm2.record_multibyte_char(fm2.start_pos + BytePos(18), 3);
cm
}
#[test]
fn t6() {
// Test bytepos_to_file_charpos in the presence of multi-byte chars
let cm = init_code_map_mbc();
let cp1 = cm.bytepos_to_file_charpos(BytePos(3));
assert_eq!(cp1, CharPos(3));
let cp2 = cm.bytepos_to_file_charpos(BytePos(6));
assert_eq!(cp2, CharPos(4));
let cp3 = cm.bytepos_to_file_charpos(BytePos(56));
assert_eq!(cp3, CharPos(12));
let cp4 = cm.bytepos_to_file_charpos(BytePos(61));
assert_eq!(cp4, CharPos(15));
}
#[test]
fn t7() {
// Test span_to_lines for a span ending at the end of filemap
let cm = init_code_map();
let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
let file_lines = cm.span_to_lines(span).unwrap();
assert_eq!(file_lines.file.name, "blork.rs");
assert_eq!(file_lines.lines.len(), 1);
assert_eq!(file_lines.lines[0].line_index, 1);
}
/// Given a string like " ~~~~~~~~~~~~ ", produces a span
/// coverting that range. The idea is that the string has the same
/// length as the input, and we uncover the byte positions. Note
/// that this can span lines and so on.
fn span_from_selection(input: &str, selection: &str) -> Span {
assert_eq!(input.len(), selection.len());
let left_index = selection.find('~').unwrap() as u32;
let right_index = selection.rfind('~').map(|x|x as u32).unwrap_or(left_index);
Span { lo: BytePos(left_index), hi: BytePos(right_index + 1), expn_id: NO_EXPANSION }
}
/// Test span_to_snippet and span_to_lines for a span coverting 3
/// lines in the middle of a file.
#[test]
fn span_to_snippet_and_lines_spanning_multiple_lines() {
let cm = CodeMap::new();
let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
let selection = " \n ~~\n~~~\n~~~~~ \n \n";
cm.new_filemap_and_lines("blork.rs", None, inputtext);
let span = span_from_selection(inputtext, selection);
// check that we are extracting the text we thought we were extracting
assert_eq!(&cm.span_to_snippet(span).unwrap(), "BB\nCCC\nDDDDD");
// check that span_to_lines gives us the complete result with the lines/cols we expected
let lines = cm.span_to_lines(span).unwrap();
let expected = vec![
LineInfo { line_index: 1, start_col: CharPos(4), end_col: CharPos(6) },
LineInfo { line_index: 2, start_col: CharPos(0), end_col: CharPos(3) },
LineInfo { line_index: 3, start_col: CharPos(0), end_col: CharPos(5) }
];
assert_eq!(lines.lines, expected);
}
#[test]
fn t8() {
// Test span_to_snippet for a span ending at the end of filemap
let cm = init_code_map();
let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
let snippet = cm.span_to_snippet(span);
assert_eq!(snippet, Ok("second line".to_string()));
}
#[test]
fn t9() {
// Test span_to_str for a span ending at the end of filemap
let cm = init_code_map();
let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
let sstr = cm.span_to_string(span);
assert_eq!(sstr, "blork.rs:2:1: 2:12");
}
#[test]
fn t10() {
// Test span_to_expanded_string works in base case (no expansion)
let cm = init_code_map();
let span = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
let sstr = cm.span_to_expanded_string(span);
assert_eq!(sstr, "blork.rs:1:1: 1:12\n`first line.`\n");
let span = Span { lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION };
let sstr = cm.span_to_expanded_string(span);
assert_eq!(sstr, "blork.rs:2:1: 2:12\n`second line`\n");
}
#[test]
fn t11() {
// Test span_to_expanded_string works with expansion
let cm = init_code_map();
let root = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
let format = ExpnFormat::MacroBang(keywords::Invalid.name());
let callee = NameAndSpan { format: format,
allow_internal_unstable: false,
span: None };
let info = ExpnInfo { call_site: root, callee: callee };
let id = cm.record_expansion(info);
let sp = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id };
let sstr = cm.span_to_expanded_string(sp);
assert_eq!(sstr,
"blork.rs:2:1: 2:12\n`second line`\n Callsite:\n \
blork.rs:1:1: 1:12\n `first line.`\n");
}
/// Test merging two spans on the same line
#[test]
fn span_merging() {
let cm = CodeMap::new();
let inputtext = "bbbb BB bb CCC\n";
let selection1 = " ~~ \n";
let selection2 = " ~~~\n";
cm.new_filemap_and_lines("blork.rs", None, inputtext);
let span1 = span_from_selection(inputtext, selection1);
let span2 = span_from_selection(inputtext, selection2);
if let Some(sp) = cm.merge_spans(span1, span2) {
let sstr = cm.span_to_expanded_string(sp);
assert_eq!(sstr, "blork.rs:1:6: 1:15\n`BB bb CCC`\n");
}
else {
assert!(false);
}
}
/// Test failing to merge two spans on different lines
#[test]
fn span_merging_fail() {
let cm = CodeMap::new();
let inputtext = "bbbb BB\ncc CCC\n";
let selection1 = " ~~\n \n";
let selection2 = " \n ~~~\n";
cm.new_filemap_and_lines("blork.rs", None, inputtext);
let span1 = span_from_selection(inputtext, selection1);
let span2 = span_from_selection(inputtext, selection2);
assert!(cm.merge_spans(span1, span2).is_none());
}
/// Returns the span corresponding to the `n`th occurrence of
/// `substring` in `source_text`.
trait CodeMapExtension {
fn span_substr(&self,
file: &Rc<FileMap>,
source_text: &str,
substring: &str,
n: usize)
-> Span;
}
impl CodeMapExtension for CodeMap {
fn span_substr(&self,
file: &Rc<FileMap>,
source_text: &str,
substring: &str,
n: usize)
-> Span
{
println!("span_substr(file={:?}/{:?}, substring={:?}, n={})",
file.name, file.start_pos, substring, n);
let mut i = 0;
let mut hi = 0;
loop {
let offset = source_text[hi..].find(substring).unwrap_or_else(|| {
panic!("source_text `{}` does not have {} occurrences of `{}`, only {}",
source_text, n, substring, i);
});
let lo = hi + offset;
hi = lo + substring.len();
if i == n {
let span = Span {
lo: BytePos(lo as u32 + file.start_pos.0),
hi: BytePos(hi as u32 + file.start_pos.0),
expn_id: NO_EXPANSION,
};
assert_eq!(&self.span_to_snippet(span).unwrap()[..],
substring);
return span;
}
i += 1;
}
}
}
fn init_expansion_chain(cm: &CodeMap) -> Span {
// Creates an expansion chain containing two recursive calls
// root -> expA -> expA -> expB -> expB -> end
let root = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
let format_root = ExpnFormat::MacroBang(keywords::Invalid.name());
let callee_root = NameAndSpan { format: format_root,
allow_internal_unstable: false,
span: Some(root) };
let info_a1 = ExpnInfo { call_site: root, callee: callee_root };
let id_a1 = cm.record_expansion(info_a1);
let span_a1 = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id_a1 };
let format_a = ExpnFormat::MacroBang(keywords::As.name());
let callee_a = NameAndSpan { format: format_a,
allow_internal_unstable: false,
span: Some(span_a1) };
let info_a2 = ExpnInfo { call_site: span_a1, callee: callee_a.clone() };
let id_a2 = cm.record_expansion(info_a2);
let span_a2 = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id_a2 };
let info_b1 = ExpnInfo { call_site: span_a2, callee: callee_a };
let id_b1 = cm.record_expansion(info_b1);
let span_b1 = Span { lo: BytePos(25), hi: BytePos(36), expn_id: id_b1 };
let format_b = ExpnFormat::MacroBang(keywords::Box.name());
let callee_b = NameAndSpan { format: format_b,
allow_internal_unstable: false,
span: None };
let info_b2 = ExpnInfo { call_site: span_b1, callee: callee_b.clone() };
let id_b2 = cm.record_expansion(info_b2);
let span_b2 = Span { lo: BytePos(25), hi: BytePos(36), expn_id: id_b2 };
let info_end = ExpnInfo { call_site: span_b2, callee: callee_b };
let id_end = cm.record_expansion(info_end);
Span { lo: BytePos(37), hi: BytePos(48), expn_id: id_end }
}
#[test]
fn t12() {
// Test span_to_expanded_string collapses recursive macros and handles
// recursive callsite and callee expansions
let cm = init_code_map();
let end = init_expansion_chain(&cm);
let sstr = cm.span_to_expanded_string(end);
let res_str =
r"blork2.rs:2:1: 2:12
`second line`
Callsite:
...
blork2.rs:1:1: 1:12
`first line.`
Callee:
blork.rs:2:1: 2:12
`second line`
Callee:
blork.rs:1:1: 1:12
`first line.`
Callsite:
blork.rs:1:1: 1:12
`first line.`
Callsite:
...
blork.rs:2:1: 2:12
`second line`
Callee:
blork.rs:1:1: 1:12
`first line.`
Callsite:
blork.rs:1:1: 1:12
`first line.`
";
assert_eq!(sstr, res_str);
}
}