Update some out-of-date information

src/appendix/humorust.md

@@ -10,4 +10,4 @@ enlightening?
 - [Rust Koans](https://users.rust-lang.org/t/rust-koans/2408)
 - [`break rust;`](https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=0ab2bd6a9d722e0f05a95e2a5dcf89cc)
 - [The Nomicon Intro](https://doc.rust-lang.org/stable/nomicon/)
-- [`rustc-ty` renaming punfest](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/rustc-ty.20naming.20bikeshed.20.2F.20punfest.20(was.3A.20design.20meeting.202.2E.2E.2E/near/189906455 )
+- [`rustc-ty` renaming punfest](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/rustc-ty.20naming.20bikeshed.20.2F.20punfest.20\(was.3A.20design.20meeting.202.2E.2E.2E/near/189906455)

src/backend/updating-llvm.md

@@ -66,9 +66,9 @@ Example PRs look like:
 
 ## Feature updates
 
-> Note that this is all information as applies to the current day in age. This
-> process for updating LLVM changes with practically all LLVM updates, so this
-> may be out of date!
+> Note that this information is as of the time of this writing <!-- date:
+2018-12 --> (December 2018). The process for updating LLVM changes with
+practically all LLVM updates, so this may be out of date!
 
 Unlike bugfixes, updating to pick up a new feature of LLVM typically requires a
 lot more work. This is where we can't reasonably cherry-pick commits backwards

src/building/new-target.md

@@ -8,27 +8,49 @@ relevant to your desired goal.
 
 For very new targets, you may need to use a different fork of LLVM
 than what is currently shipped with Rust. In that case, navigate to
-the `src/llvm_project` git submodule (you might need to run `x.py
+the `src/llvm-project` git submodule (you might need to run `x.py
 check` at least once so the submodule is updated), check out the
 appropriate commit for your fork, then commit that new submodule
 reference in the main Rust repository.
 
 An example would be:
 
 ```
-cd src/llvm_project
+cd src/llvm-project
 git remote add my-target-llvm some-llvm-repository
 git checkout my-target-llvm/my-branch
 cd ..
 git add llvm_target
 git commit -m 'Use my custom LLVM'
 ```
 
-If you have a local LLVM checkout that is already built, you *may* be
-able to configure Rust to treat your build as the [system
-LLVM][sysllvm] to avoid redundant builds.
+### Using pre-built LLVM
 
-[sysllvm]: ./suggested.md#skipping-llvm-build
+If you have a local LLVM checkout that is already built, you may be
+able to configure Rust to treat your build as the [system LLVM][sysllvm]
+to avoid redundant builds.
+
+You can tell Rust to use a pre-built version of LLVM using the `target` section
+of `config.toml`:
+
+```toml
+[target.x86_64-unknown-linux-gnu]
+llvm-config = "/path/to/llvm/llvm-7.0.1/bin/llvm-config"
+```
+
+If you are attempting to use a system LLVM, we have observed the following paths
+before, though they may be different from your system:
+
+- `/usr/bin/llvm-config-8`
+- `/usr/lib/llvm-8/bin/llvm-config`
+
+Note that you need to have the LLVM `FileCheck` tool installed, which is used
+for codegen tests. This tool is normally built with LLVM, but if you use your
+own preinstalled LLVM, you will need to provide `FileCheck` in some other way.
+On Debian-based systems, you can install the `llvm-N-tools` package (where `N`
+is the LLVM version number, e.g. `llvm-8-tools`). Alternately, you can specify
+the path to `FileCheck` with the `llvm-filecheck` config item in `config.toml`
+or you can disable codegen test with the `codegen-tests` item in `config.toml`.
 
 ## Creating a target specification
 

src/getting-started.md

@@ -79,7 +79,7 @@ recommend trying to build on a Raspberry Pi :P
 
 Building the compiler takes more than half an hour on my moderately powerful
 laptop. The first time you build the compiler, LLVM will also be built unless
-you use your system's LLVM ([see below][configsec]).
+you use CI-built LLVM ([see below][configsec]).
 
 [configsec]: #configuring-the-compiler
 
@@ -123,7 +123,7 @@ The compiler has a configuration file which contains a ton of settings. We will
 provide some recommendations here that should work for most, but [check out
 this chapter for more info][config].
 
-[config]: ./building/how-to-build-and-run.html#create-a-configtoml
+[config]: ./building/how-to-build-and-run.md#create-a-configtoml
 
 In the top level of the repo:
 
@@ -150,11 +150,23 @@ To get started, try one of the following commands:
 For more suggestions, see https://rustc-dev-guide.rust-lang.org/building/suggested.html
 ```
 
-You may also want to set up [system LLVM][sysllvm] to avoid building LLVM from source.
+Note that by default, `x.py setup` will use CI-built LLVM if available for your
+platform so that you don't need to build LLVM in addition to building the
+compiler. In some circumstances, such as when updating the version of LLVM used
+by `rustc`, you may want to temporarily disable this feature. See the ["Updating
+LLVM" section] for more.
 
-[sysllvm]: ./building/suggested.html#skipping-llvm-build
+If you want to download LLVM from CI without running `x.py setup`, you can set
+the `download-ci-llvm` option to `true` in your `config.toml`:
 
-### `./x.py` Intro
+```toml
+[llvm]
+download-ci-llvm = true
+```
+
+["Updating LLVM" section]: https://rustc-dev-guide.rust-lang.org/backend/updating-llvm.html?highlight=download-ci-llvm#feature-updates
+
+### x.py Intro
 
 `rustc` is a _bootstrapping_ compiler, which means that it is written in Rust
 and thus needs to be compiled by itself. So where do you

src/traits/chalk.md

@@ -35,7 +35,7 @@ and designs for the trait system.
 
 **rustc**. Once we are happy with the logical rules, we proceed to
 implementing them in rustc. We map our struct, trait, and impl declarations
-into logical inference rules in the [lowering module in rustc](./lowering-module.md).
+into logical inference rules in the lowering module in rustc.
 
 [chalk]: https://github.com/rust-lang/chalk
 [rustc_traits]: https://github.com/rust-lang/rust/tree/master/compiler/rustc_traits