1 # Compiler Test Documentation
3 In the Rust project, we use a special set of commands embedded in
4 comments to test the Rust compiler. There are two groups of commands:
9 Both types of commands are inside comments, but header commands should
10 be in a comment before any code.
12 ## Summary of Error Info Commands
14 Error commands specify something about certain lines of the
15 program. They tell the test what kind of error and what message you
18 * `~`: Associates the following error level and message with the
20 * `~|`: Associates the following error level and message with the same
21 line as the previous comment
22 * `~^`: Associates the following error level and message with the
23 previous line. Each caret (`^`) that you add adds a line to this, so
24 `~^^^^^^^` is seven lines up.
26 The error levels that you can have are:
31 4. `HELP` and `SUGGESTION`*
33 \* **Note**: `SUGGESTION` must follow immediately after `HELP`.
35 ## Summary of Header Commands
37 Header commands specify something about the entire test file as a
38 whole, instead of just a few lines inside the test.
40 * `ignore-X` where `X` is an architecture, OS or stage will ignore the test accordingly
41 * `ignore-pretty` will not compile the pretty-printed test (this is done to test the pretty-printer, but might not always work)
42 * `ignore-test` always ignores the test
43 * `ignore-lldb` and `ignore-gdb` will skip the debuginfo tests
44 * `min-{gdb,lldb}-version`
45 * `should-fail` indicates that the test should fail; used for "meta testing",
46 where we test the compiletest program itself to check that it will generate
47 errors in appropriate scenarios
51 Certain classes of tests support "revisions" (as of the time of this
52 writing, this includes run-pass, compile-fail, run-fail, and
53 incremental, though incremental tests are somewhat
54 different). Revisions allow a single test file to be used for multiple
55 tests. This is done by adding a special header at the top of the file:
58 // revisions: foo bar baz
61 This will result in the test being compiled (and tested) three times,
62 once with `--cfg foo`, once with `--cfg bar`, and once with `--cfg
63 baz`. You can therefore use `#[cfg(foo)]` etc within the test to tweak
64 each of these results.
66 You can also customize headers and expected error messages to a particular
67 revision. To do this, add `[foo]` (or `bar`, `baz`, etc) after the `//`
71 // A flag to pass in only for cfg `foo`:
72 //[foo]compile-flags: -Z verbose
76 let x: usize = 32_u32; //[foo]~ ERROR mismatched types
80 Note that not all headers have meaning when customized too a revision.
81 For example, the `ignore-test` header (and all "ignore" headers)
82 currently only apply to the test as a whole, not to particular
83 revisions. The only headers that are intended to really work when
84 customized to a revision are error patterns and compiler flags.