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99 lines
2.7 KiB
Rust
99 lines
2.7 KiB
Rust
// run-pass
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// needs-unwind
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#![allow(unused_imports)]
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// Ideally, any macro call with a trailing comma should behave
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// identically to a call without the comma.
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//
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// This checks the behavior of macros with trailing commas in key
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// places where regressions in behavior seem highly possible (due
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// to it being e.g., a place where the addition of an argument
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// causes it to go down a code path with subtly different behavior).
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//
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// There is a companion failing test.
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// compile-flags: --test -C debug_assertions=yes
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// revisions: std core
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#![cfg_attr(core, no_std)]
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#[cfg(core)]
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use core::fmt;
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#[cfg(std)]
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use std::fmt;
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// an easy mistake in the implementation of 'assert!'
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// would cause this to say "explicit panic"
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#[test]
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#[should_panic(expected = "assertion failed")]
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fn assert_1arg() {
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assert!(false,);
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}
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// same as 'assert_1arg'
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#[test]
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#[should_panic(expected = "assertion failed")]
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fn debug_assert_1arg() {
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debug_assert!(false,);
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}
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// make sure we don't accidentally forward to `write!("text")`
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#[cfg(std)]
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#[test]
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fn writeln_1arg() {
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use fmt::Write;
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let mut s = String::new();
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writeln!(&mut s,).unwrap();
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assert_eq!(&s, "\n");
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}
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// A number of format_args-like macros have special-case treatment
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// for a single message string, which is not formatted.
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//
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// This test ensures that the addition of a trailing comma does not
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// suddenly cause these strings to get formatted when they otherwise
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// would not be. This is an easy mistake to make by having such a macro
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// accept ", $($tok:tt)*" instead of ", $($tok:tt)+" after its minimal
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// set of arguments.
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//
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// (Example: Issue #48042)
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#[test]
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#[allow(non_fmt_panics)]
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fn to_format_or_not_to_format() {
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// ("{}" is the easiest string to test because if this gets
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// sent to format_args!, it'll simply fail to compile.
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// "{{}}" is an example of an input that could compile and
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// produce an incorrect program, but testing the panics
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// would be burdensome.)
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let falsum = || false;
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assert!(true, "{}",);
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// assert_eq!(1, 1, "{}",); // see check-fail
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// assert_ne!(1, 2, "{}",); // see check-fail
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debug_assert!(true, "{}",);
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// debug_assert_eq!(1, 1, "{}",); // see check-fail
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// debug_assert_ne!(1, 2, "{}",); // see check-fail
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// eprint!("{}",); // see check-fail
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// eprintln!("{}",); // see check-fail
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// format!("{}",); // see check-fail
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// format_args!("{}",); // see check-fail
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if falsum() {
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panic!("{}",);
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}
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// print!("{}",); // see check-fail
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// println!("{}",); // see check-fail
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// unimplemented!("{}",); // see check-fail
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if falsum() {
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unreachable!("{}",);
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}
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// write!(&mut stdout, "{}",); // see check-fail
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// writeln!(&mut stdout, "{}",); // see check-fail
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}
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