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141719f68a
This involves replacing `nt_pretty_printing_compatibility_hack` with `stream_pretty_printing_compatibility_hack`. The handling of statements in `transcribe` is slightly different to other nonterminal kinds, due to the lack of `from_ast` implementation for empty statements. Notable test changes: - `tests/ui/proc-macro/expand-to-derive.rs`: the diff looks large but the only difference is the insertion of a single invisible-delimited group around a metavar.
57 lines
1.6 KiB
Rust
57 lines
1.6 KiB
Rust
// Check that we are refusing to match on complex nonterminals for which tokens are
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// unavailable and we'd have to go through AST comparisons.
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#![feature(decl_macro)]
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macro simple_nonterminal($nt_ident: ident, $nt_lifetime: lifetime, $nt_tt: tt) {
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macro n(a $nt_ident b $nt_lifetime c $nt_tt d) {
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struct S;
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}
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n!(a $nt_ident b $nt_lifetime c $nt_tt d);
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}
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macro complex_nonterminal($nt_item: item) {
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macro n(a $nt_item b) {
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struct S;
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}
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n!(a $nt_item b); //~ ERROR no rules expected `item` metavariable
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}
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simple_nonterminal!(a, 'a, (x, y, z)); // OK
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complex_nonterminal!(enum E {});
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// `ident`, `lifetime`, and `tt` all work. Other fragments do not. See
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// https://doc.rust-lang.org/nightly/reference/macros-by-example.html#forwarding-a-matched-fragment
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macro_rules! foo {
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(ident $x:ident) => { bar!(ident $x); };
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(lifetime $x:lifetime) => { bar!(lifetime $x); };
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(tt $x:tt) => { bar!(tt $x); };
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(expr $x:expr) => { bar!(expr $x); }; //~ ERROR: no rules expected expression `3`
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(literal $x:literal) => { bar!(literal $x); }; //~ ERROR: no rules expected literal `4`
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(path $x:path) => { bar!(path $x); }; //~ ERROR: no rules expected `path` metavariable
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(stmt $x:stmt) => { bar!(stmt $x); }; //~ ERROR: no rules expected `stmt` metavariable
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}
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macro_rules! bar {
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(ident abc) => {};
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(lifetime 'abc) => {};
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(tt 2) => {};
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(expr 3) => {};
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(literal 4) => {};
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(path a::b::c) => {};
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(stmt let abc = 0) => {};
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}
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foo!(ident abc);
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foo!(lifetime 'abc);
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foo!(tt 2);
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foo!(expr 3);
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foo!(literal 4);
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foo!(path a::b::c);
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foo!(stmt let abc = 0);
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fn main() {}
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