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| author | Felix S. Klock II <pnkfelix@pnkfx.org> | 2018-08-30 13:16:59 +0200 |
|---|---|---|
| committer | Felix S. Klock II <pnkfelix@pnkfx.org> | 2018-09-06 13:00:26 +0200 |
| commit | 7834c2284801766f9925576e8f4d05d7cb7b23dd (patch) | |
| tree | b0676510293a1ab5317291bd79f4136754dae764 /src/test/ui/run-pass/macros/macro-comma-behavior.rs | |
| parent | 20ca02569ae3e1dc29962e92739fbab632abf241 (diff) | |
| download | rust-7834c2284801766f9925576e8f4d05d7cb7b23dd.tar.gz rust-7834c2284801766f9925576e8f4d05d7cb7b23dd.zip | |
Migrated slew of run-pass tests to various subdirectories of `ui/run-pass/`.
Diffstat (limited to 'src/test/ui/run-pass/macros/macro-comma-behavior.rs')
| -rw-r--r-- | src/test/ui/run-pass/macros/macro-comma-behavior.rs | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/test/ui/run-pass/macros/macro-comma-behavior.rs b/src/test/ui/run-pass/macros/macro-comma-behavior.rs new file mode 100644 index 00000000000..2a434009e13 --- /dev/null +++ b/src/test/ui/run-pass/macros/macro-comma-behavior.rs @@ -0,0 +1,98 @@ +// 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. + +// Ideally, any macro call with a trailing comma should behave +// identically to a call without the comma. +// +// This checks the behavior of macros with trailing commas in key +// places where regressions in behavior seem highly possible (due +// to it being e.g. a place where the addition of an argument +// causes it to go down a code path with subtly different behavior). +// +// There is a companion test in compile-fail. + +// compile-flags: --test -C debug_assertions=yes +// revisions: std core + +#![cfg_attr(core, no_std)] + +#[cfg(std)] use std::fmt; +#[cfg(core)] use core::fmt; + +// an easy mistake in the implementation of 'assert!' +// would cause this to say "explicit panic" +#[test] +#[should_panic(expected = "assertion failed")] +fn assert_1arg() { + assert!(false,); +} + +// same as 'assert_1arg' +#[test] +#[should_panic(expected = "assertion failed")] +fn debug_assert_1arg() { + debug_assert!(false,); +} + +// make sure we don't accidentally forward to `write!("text")` +#[cfg(std)] +#[test] +fn writeln_1arg() { + use fmt::Write; + + let mut s = String::new(); + writeln!(&mut s,).unwrap(); + assert_eq!(&s, "\n"); +} + +// A number of format_args-like macros have special-case treatment +// for a single message string, which is not formatted. +// +// This test ensures that the addition of a trailing comma does not +// suddenly cause these strings to get formatted when they otherwise +// would not be. This is an easy mistake to make by having such a macro +// accept ", $($tok:tt)*" instead of ", $($tok:tt)+" after its minimal +// set of arguments. +// +// (Example: Issue #48042) +#[test] +fn to_format_or_not_to_format() { + // ("{}" is the easiest string to test because if this gets + // sent to format_args!, it'll simply fail to compile. + // "{{}}" is an example of an input that could compile and + // produce an incorrect program, but testing the panics + // would be burdensome.) + let falsum = || false; + + assert!(true, "{}",); + + // assert_eq!(1, 1, "{}",); // see compile-fail + // assert_ne!(1, 2, "{}",); // see compile-fail + + debug_assert!(true, "{}",); + + // debug_assert_eq!(1, 1, "{}",); // see compile-fail + // debug_assert_ne!(1, 2, "{}",); // see compile-fail + // eprint!("{}",); // see compile-fail + // eprintln!("{}",); // see compile-fail + // format!("{}",); // see compile-fail + // format_args!("{}",); // see compile-fail + + if falsum() { panic!("{}",); } + + // print!("{}",); // see compile-fail + // println!("{}",); // see compile-fail + // unimplemented!("{}",); // see compile-fail + + if falsum() { unreachable!("{}",); } + + // write!(&mut stdout, "{}",); // see compile-fail + // writeln!(&mut stdout, "{}",); // see compile-fail +} |
