129fe9a998
Explaining something in the output that surprised me.
105 lines
2.9 KiB
Rust
105 lines
2.9 KiB
Rust
// check-pass
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// compile-flags: -Z span-debug --error-format human
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// aux-build:test-macros.rs
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// Regression test for issue #75930
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// Tests that we cfg-strip all targets before invoking
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// a derive macro
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// We need '--error-format human' to stop compiletest from
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// trying to interpret proc-macro output as JSON messages
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// (a pretty-printed struct may cause a line to start with '{' )
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// FIXME: We currently lose spans here (see issue #43081)
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#![no_std] // Don't load unnecessary hygiene information from std
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extern crate std;
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#[macro_use]
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extern crate test_macros;
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// Note: the expected output contains this sequence:
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// ```
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// Punct {
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// ch: '<',
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// spacing: Joint,
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// span: $DIR/issue-75930-derive-cfg.rs:25:11: 25:12 (#0),
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// },
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// Ident {
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// ident: "B",
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// span: $DIR/issue-75930-derive-cfg.rs:25:29: 25:30 (#0),
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// },
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// ```
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// It's surprising to see a `Joint` token tree followed by an `Ident` token
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// tree, because `Joint` is supposed to only be used if the following token is
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// `Punct`.
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//
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// It is because of this code from below:
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// ```
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// struct Foo<#[cfg(FALSE)] A, B>
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// ```
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// When the token stream is formed during parsing, `<` is followed immediately
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// by `#`, which is punctuation, so it is marked `Joint`. But before being
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// passed to the proc macro it is rewritten to this:
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// ```
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// struct Foo<B>
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// ```
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// But the `Joint` marker on the `<` is not updated. Perhaps it should be
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// corrected before being passed to the proc macro? But a prior attempt to do
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// that kind of correction caused the problem seen in #76399, so maybe not.
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#[print_helper(a)] //~ WARN derive helper attribute is used before it is introduced
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//~| WARN this was previously accepted
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#[cfg_attr(not(FALSE), allow(dead_code))]
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#[print_attr]
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#[derive(Print)]
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#[print_helper(b)]
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struct Foo<#[cfg(FALSE)] A, B> {
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#[cfg(FALSE)] first: String,
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#[cfg_attr(FALSE, deny(warnings))] second: bool,
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third: [u8; {
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#[cfg(FALSE)] struct Bar;
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#[cfg(not(FALSE))] struct Inner;
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#[cfg(FALSE)] let a = 25;
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match true {
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#[cfg(FALSE)] true => {},
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#[cfg_attr(not(FALSE), allow(warnings))] false => {},
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_ => {}
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};
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#[print_helper(should_be_removed)]
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fn removed_fn() {
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#![cfg(FALSE)]
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}
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#[print_helper(c)] #[cfg(not(FALSE))] fn kept_fn() {
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#![cfg(not(FALSE))]
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let my_val = true;
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}
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enum TupleEnum {
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Foo(
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#[cfg(FALSE)] u8,
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#[cfg(FALSE)] bool,
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#[cfg(not(FALSE))] i32,
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#[cfg(FALSE)] String, u8
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)
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}
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struct TupleStruct(
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#[cfg(FALSE)] String,
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#[cfg(not(FALSE))] i32,
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#[cfg(FALSE)] bool,
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u8
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);
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fn plain_removed_fn() {
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#![cfg_attr(not(FALSE), cfg(FALSE))]
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}
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0
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}],
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#[print_helper(d)]
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fourth: B
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}
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fn main() {}
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