diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libsyntax/parse/token.rs | 31 | ||||
| -rw-r--r-- | src/libsyntax/tokenstream.rs | 8 | ||||
| -rw-r--r-- | src/test/run-pass-fulldeps/proc-macro/auxiliary/modify-ast.rs | 57 | ||||
| -rw-r--r-- | src/test/run-pass-fulldeps/proc-macro/modify-ast.rs | 37 |
4 files changed, 121 insertions, 12 deletions
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs index 35a745ccdee..0913ed86147 100644 --- a/src/libsyntax/parse/token.rs +++ b/src/libsyntax/parse/token.rs @@ -527,8 +527,17 @@ impl Token { // all span information. // // As a result, some AST nodes are annotated with the token - // stream they came from. Attempt to extract these lossless - // token streams before we fall back to the stringification. + // stream they came from. Here we attempt to extract these + // lossless token streams before we fall back to the + // stringification. + // + // During early phases of the compiler, though, the AST could + // get modified directly (e.g. attributes added or removed) and + // the internal cache of tokens my not be invalidated or + // updated. Consequently if the "lossless" token stream + // disagrees with our actuall stringification (which has + // historically been much more battle-tested) then we go with + // the lossy stream anyway (losing span information). let mut tokens = None; match nt.0 { @@ -555,13 +564,17 @@ impl Token { _ => {} } - tokens.unwrap_or_else(|| { - nt.1.force(|| { - // FIXME(jseyfried): Avoid this pretty-print + reparse hack - let source = pprust::token_to_string(self); - parse_stream_from_source_str(FileName::MacroExpansion, source, sess, Some(span)) - }) - }) + let tokens_for_real = nt.1.force(|| { + // FIXME(#43081): Avoid this pretty-print + reparse hack + let source = pprust::token_to_string(self); + parse_stream_from_source_str(FileName::MacroExpansion, source, sess, Some(span)) + }); + if let Some(tokens) = tokens { + if tokens.eq_unspanned(&tokens_for_real) { + return tokens + } + } + return tokens_for_real } } diff --git a/src/libsyntax/tokenstream.rs b/src/libsyntax/tokenstream.rs index 3a7a1b9a669..6ac04b3cdf6 100644 --- a/src/libsyntax/tokenstream.rs +++ b/src/libsyntax/tokenstream.rs @@ -118,7 +118,7 @@ impl TokenTree { (&TokenTree::Token(_, ref tk), &TokenTree::Token(_, ref tk2)) => tk == tk2, (&TokenTree::Delimited(_, ref dl), &TokenTree::Delimited(_, ref dl2)) => { dl.delim == dl2.delim && - dl.stream().trees().zip(dl2.stream().trees()).all(|(tt, tt2)| tt.eq_unspanned(&tt2)) + dl.stream().eq_unspanned(&dl2.stream()) } (_, _) => false, } @@ -240,12 +240,14 @@ impl TokenStream { /// Compares two TokenStreams, checking equality without regarding span information. pub fn eq_unspanned(&self, other: &TokenStream) -> bool { - for (t1, t2) in self.trees().zip(other.trees()) { + let mut t1 = self.trees(); + let mut t2 = other.trees(); + for (t1, t2) in t1.by_ref().zip(t2.by_ref()) { if !t1.eq_unspanned(&t2) { return false; } } - true + t1.next().is_none() && t2.next().is_none() } /// Precondition: `self` consists of a single token tree. diff --git a/src/test/run-pass-fulldeps/proc-macro/auxiliary/modify-ast.rs b/src/test/run-pass-fulldeps/proc-macro/auxiliary/modify-ast.rs new file mode 100644 index 00000000000..6f8c649c6b5 --- /dev/null +++ b/src/test/run-pass-fulldeps/proc-macro/auxiliary/modify-ast.rs @@ -0,0 +1,57 @@ +// Copyright 2018 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. + +// no-prefer-dynamic + +#![crate_type = "proc-macro"] +#![feature(proc_macro)] + +extern crate proc_macro; + +use proc_macro::*; + +#[proc_macro_attribute] +pub fn assert1(_a: TokenStream, b: TokenStream) -> TokenStream { + assert_eq(b.clone(), "pub fn foo() {}".parse().unwrap()); + b +} + +#[proc_macro_derive(Foo, attributes(foo))] +pub fn assert2(a: TokenStream) -> TokenStream { + assert_eq(a, "pub struct MyStructc { _a: i32, }".parse().unwrap()); + TokenStream::empty() +} + +fn assert_eq(a: TokenStream, b: TokenStream) { + let mut a = a.into_iter(); + let mut b = b.into_iter(); + for (a, b) in a.by_ref().zip(&mut b) { + match (a, b) { + (TokenTree::Group(a), TokenTree::Group(b)) => { + assert_eq!(a.delimiter(), b.delimiter()); + assert_eq(a.stream(), b.stream()); + } + (TokenTree::Op(a), TokenTree::Op(b)) => { + assert_eq!(a.op(), b.op()); + assert_eq!(a.spacing(), b.spacing()); + } + (TokenTree::Literal(a), TokenTree::Literal(b)) => { + assert_eq!(a.to_string(), b.to_string()); + } + (TokenTree::Term(a), TokenTree::Term(b)) => { + assert_eq!(a.to_string(), b.to_string()); + } + (a, b) => panic!("{:?} != {:?}", a, b), + } + } + + assert!(a.next().is_none()); + assert!(b.next().is_none()); +} diff --git a/src/test/run-pass-fulldeps/proc-macro/modify-ast.rs b/src/test/run-pass-fulldeps/proc-macro/modify-ast.rs new file mode 100644 index 00000000000..13a6dbd2ae5 --- /dev/null +++ b/src/test/run-pass-fulldeps/proc-macro/modify-ast.rs @@ -0,0 +1,37 @@ +// Copyright 2018 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. + +// aux-build:modify-ast.rs + +#![feature(proc_macro)] + +extern crate modify_ast; + +use modify_ast::*; + +#[derive(Foo)] +pub struct MyStructc { + #[cfg_attr(my_cfg, foo)] + _a: i32, +} + +macro_rules! a { + ($i:item) => ($i) +} + +a! { + #[assert1] + pub fn foo() {} +} + +fn main() { + let _a = MyStructc { _a: 0 }; + foo(); +} |