From d09ba5d3ce812248af448c094ebd0edcf818dfc5 Mon Sep 17 00:00:00 2001
From: christopherdumas <christopherdumas@me.com>
Date: Sat, 12 Sep 2015 08:02:01 -0700
Subject: [PATCH] Compiler test manual

---
 COMPILER_TESTS.md | 43 +++++++++++++++++++++++++++++++++++++++++++
 CONTRIBUTING.md   |  2 ++
 2 files changed, 45 insertions(+)
 create mode 100644 COMPILER_TESTS.md

diff --git a/COMPILER_TESTS.md b/COMPILER_TESTS.md
new file mode 100644
index 0000000000000..e4acf230e7211
--- /dev/null
+++ b/COMPILER_TESTS.md
@@ -0,0 +1,43 @@
+# Compiler Test Documentation
+
+In the Rust project, we use a special set of comands imbedded in
+comments to test the Rust compiler. There are two groups of commands:
+
+1. Header commands
+2. Error info commands
+
+Both types of commands are inside comments, but header commands should
+be in a comment before any code.
+
+## Summary of Error Info Commands
+
+Error commands specify something about certain lines of the
+program. They tell the test what kind of error and what message you
+are expecting.
+
+* `~`: Associates the following error level and message with the
+  current line
+* `~|`: Associates the following error level and message with the same
+  line as the previous comment
+* `~^`: Associates the following error level and message with the
+  previous line. Each caret (`^`) that you add adds a line to this, so
+  `~^^^^^^^` is seven lines up.
+
+The error levels that you can have are:
+1. `ERROR`
+2. `WARNING`
+3. `NOTE`
+4. `HELP` and `SUGGESTION`*
+
+\* **Note**: `SUGGESTION` must follow emediatly after `HELP`.
+
+## Summary of Header Commands
+
+Header commands specify something about the entire test file, as a
+whole, instead of just a few lines inside the test.
+
+* `ignore-X` where `X` is an architecture, OS or stage will ignore the test accordingly
+* `ignore-pretty` will not compile the pretty-printed test (this is done to test the pretty-printer, but might not always work)
+* `ignore-test` always ignores the test
+* `ignore-lldb` and `ignore-gdb` will skip the debuginfo tests
+* `min-{gdb,lldb}-version`
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index fd02b1e34c043..72962f7c5a889 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -224,6 +224,7 @@ are:
 * The [rust referance][rr], even though it doesn't specifically talk about Rust's internals, its a great reasource nontheless
 * Although out of date, [Tom Lee's great blog article][tlgba] is very helpful
 * [rustaceans.org][ro] is helpful, but mostly dedicated to IRC
+* The [Rust Compiler Testing Docs][rctd]
 * **Google**!
 * Don't be afraid to ask! The Rust community is friendly and helpful.
 
@@ -232,3 +233,4 @@ are:
 [rr]: https://doc.rust-lang.org/book/README.html
 [tlgba]: http://tomlee.co/2014/04/03/a-more-detailed-tour-of-the-rust-compiler/
 [ro]: http://www.rustaceans.org/
+[rctd]: ./COMPILER_TESTS.md