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Auto merge of #26347 - nagisa:macro-exp, r=nrc
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r? @nrc, because breakage was caused by #25318
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bors committed Jun 18, 2015
2 parents 713d917 + 09ed27c commit 20d23d8
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Showing 4 changed files with 106 additions and 72 deletions.
97 changes: 44 additions & 53 deletions src/libsyntax/codemap.rs
Original file line number Diff line number Diff line change
Expand Up @@ -17,7 +17,7 @@
//! within the CodeMap, which upon request can be converted to line and column
//! information, source code snippets, etc.
pub use self::MacroFormat::*;
pub use self::ExpnFormat::*;

use std::cell::RefCell;
use std::ops::{Add, Sub};
Expand Down Expand Up @@ -228,17 +228,17 @@ pub struct FileMapAndBytePos { pub fm: Rc<FileMap>, pub pos: BytePos }


// _____________________________________________________________________________
// MacroFormat, NameAndSpan, ExpnInfo, ExpnId
// ExpnFormat, NameAndSpan, ExpnInfo, ExpnId
//

/// The syntax with which a macro was invoked.
#[derive(Clone, Copy, Hash, Debug)]
pub enum MacroFormat {
/// The source of expansion.
#[derive(Clone, Copy, Hash, Debug, PartialEq, Eq)]
pub enum ExpnFormat {
/// e.g. #[derive(...)] <item>
MacroAttribute,
/// e.g. `format!()`
MacroBang,
/// Expansion performed by the compiler (libsyntax::expand).
/// Syntax sugar expansion performed by the compiler (libsyntax::expand).
CompilerExpansion,
}

Expand All @@ -248,7 +248,7 @@ pub struct NameAndSpan {
/// with this Span.
pub name: String,
/// The format with which the macro was invoked.
pub format: MacroFormat,
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.
Expand All @@ -259,11 +259,11 @@ pub struct NameAndSpan {
pub span: Option<Span>
}

/// Extra information for tracking macro expansion of spans
/// Extra information for tracking spans of macro and syntax sugar expansion
#[derive(Hash, Debug)]
pub struct ExpnInfo {
/// The location of the actual macro invocation, e.g. `let x =
/// foo!();`
/// 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
Expand All @@ -272,12 +272,7 @@ pub struct ExpnInfo {
/// call_site span would have its own ExpnInfo, with the call_site
/// pointing to the `foo!` invocation.
pub call_site: Span,
/// Information about the macro and its definition.
///
/// The `callee` of the inner expression in the `call_site`
/// example would point to the `macro_rules! bar { ... }` and that
/// of the `bar!()` invocation would point to the `macro_rules!
/// foo { ... }`.
/// Information about the expansion.
pub callee: NameAndSpan
}

Expand Down Expand Up @@ -677,7 +672,39 @@ impl CodeMap {

/// Lookup source information about a BytePos
pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
self.lookup_pos(pos)
let FileMapAndLine {fm: f, line: a} = self.lookup_line(pos);
let line = a + 1; // Line numbers start at 1
let chpos = self.bytepos_to_file_charpos(pos);
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
}
}

fn lookup_line(&self, pos: BytePos) -> FileMapAndLine {
let idx = self.lookup_filemap_idx(pos);

let files = self.files.borrow();
let f = (*files)[idx].clone();
let mut a = 0;
{
let lines = f.lines.borrow();
let mut b = lines.len();
while b - a > 1 {
let m = (a + b) / 2;
if (*lines)[m] > pos { b = m; } else { a = m; }
}
}
FileMapAndLine {fm: f, line: a}
}

pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt {
Expand Down Expand Up @@ -877,42 +904,6 @@ impl CodeMap {
return a;
}

fn lookup_line(&self, pos: BytePos) -> FileMapAndLine {
let idx = self.lookup_filemap_idx(pos);

let files = self.files.borrow();
let f = (*files)[idx].clone();
let mut a = 0;
{
let lines = f.lines.borrow();
let mut b = lines.len();
while b - a > 1 {
let m = (a + b) / 2;
if (*lines)[m] > pos { b = m; } else { a = m; }
}
}
FileMapAndLine {fm: f, line: a}
}

fn lookup_pos(&self, pos: BytePos) -> Loc {
let FileMapAndLine {fm: f, line: a} = self.lookup_line(pos);
let line = a + 1; // Line numbers start at 1
let chpos = self.bytepos_to_file_charpos(pos);
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
}
}

pub fn record_expansion(&self, expn_info: ExpnInfo) -> ExpnId {
let mut expansions = self.expansions.borrow_mut();
expansions.push(expn_info);
Expand Down
39 changes: 23 additions & 16 deletions src/libsyntax/ext/base.rs
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@ pub use self::SyntaxExtension::*;
use ast;
use ast::Name;
use codemap;
use codemap::{CodeMap, Span, ExpnId, ExpnInfo, NO_EXPANSION};
use codemap::{CodeMap, Span, ExpnId, ExpnInfo, NO_EXPANSION, CompilerExpansion};
use ext;
use ext::expand;
use ext::tt::macro_rules;
Expand Down Expand Up @@ -658,6 +658,8 @@ impl<'a> ExtCtxt<'a> {
})
}
pub fn backtrace(&self) -> ExpnId { self.backtrace }

/// Original span that caused the current exapnsion to happen.
pub fn original_span(&self) -> Span {
let mut expn_id = self.backtrace;
let mut call_site = None;
Expand All @@ -672,26 +674,31 @@ impl<'a> ExtCtxt<'a> {
}
call_site.expect("missing expansion backtrace")
}
pub fn original_span_in_file(&self) -> Span {

/// Returns span for the macro which originally caused the current expansion to happen.
///
/// Stops backtracing at include! boundary.
pub fn expansion_cause(&self) -> Span {
let mut expn_id = self.backtrace;
let mut call_site = None;
let mut last_macro = None;
loop {
let expn_info = self.codemap().with_expn_info(expn_id, |ei| {
ei.map(|ei| (ei.call_site, ei.callee.name == "include"))
});
match expn_info {
None => break,
Some((cs, is_include)) => {
if is_include {
// Don't recurse into file using "include!".
break;
if self.codemap().with_expn_info(expn_id, |info| {
info.map_or(None, |i| {
if i.callee.name == "include" {
// Stop going up the backtrace once include! is encountered
return None;
}
call_site = Some(cs);
expn_id = cs.expn_id;
}
expn_id = i.call_site.expn_id;
if i.callee.format != CompilerExpansion {
last_macro = Some(i.call_site)
}
return Some(());
})
}).is_none() {
break
}
}
call_site.expect("missing expansion backtrace")
last_macro.expect("missing expansion backtrace")
}

pub fn mod_push(&mut self, i: ast::Ident) { self.mod_path.push(i); }
Expand Down
6 changes: 3 additions & 3 deletions src/libsyntax/ext/source_util.rs
Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,7 @@ pub fn expand_line(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult+'static> {
base::check_zero_tts(cx, sp, tts, "line!");

let topmost = cx.original_span_in_file();
let topmost = cx.expansion_cause();
let loc = cx.codemap().lookup_char_pos(topmost.lo);

base::MacEager::expr(cx.expr_u32(topmost, loc.line as u32))
Expand All @@ -45,7 +45,7 @@ pub fn expand_column(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult+'static> {
base::check_zero_tts(cx, sp, tts, "column!");

let topmost = cx.original_span_in_file();
let topmost = cx.expansion_cause();
let loc = cx.codemap().lookup_char_pos(topmost.lo);

base::MacEager::expr(cx.expr_u32(topmost, loc.col.to_usize() as u32))
Expand All @@ -58,7 +58,7 @@ pub fn expand_file(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult+'static> {
base::check_zero_tts(cx, sp, tts, "file!");

let topmost = cx.original_span_in_file();
let topmost = cx.expansion_cause();
let loc = cx.codemap().lookup_char_pos(topmost.lo);
let filename = token::intern_and_get_ident(&loc.file.name);
base::MacEager::expr(cx.expr_str(topmost, filename))
Expand Down
36 changes: 36 additions & 0 deletions src/test/run-pass/issue-26322.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,36 @@
// Copyright 2015 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.

macro_rules! columnline {
() => (
(column!(), line!())
)
}

macro_rules! indirectcolumnline {
() => (
(||{ columnline!() })()
)
}

fn main() {
let closure = || {
columnline!()
};
let iflet = if let Some(_) = Some(0) {
columnline!()
} else { (0, 0) };
let cl = columnline!();
assert_eq!(closure(), (8, 25));
assert_eq!(iflet, (8, 28));
assert_eq!(cl, (13, 30));
let indirect = indirectcolumnline!();
assert_eq!(indirect, (19, 34));
}

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