docs(contrib): Pull impl info out of architecture

src/doc/contrib/src/SUMMARY.md

@@ -7,10 +7,14 @@
     - [Release process](./process/release.md)
     - [Unstable features](./process/unstable.md)
 - [Design Principles](./design.md)
+- [Implementing a Change](./implementation/index.md)
+    - [Architecture](./implementation/architecture.md)
+    - [New subcommands](./implementation/subcommands.md)
+    - [Console Output](./implementation/console.md)
+    - [Filesystem](./implementation/filesystem.md)
+    - [Debugging](./implementation/debugging.md)
 - [Architecture](./architecture/index.md)
     - [Codebase Overview](./architecture/codebase.md)
-    - [SubCommands](./architecture/subcommands.md)
-    - [Console Output](./architecture/console.md)
     - [Packages and Resolution](./architecture/packages.md)
     - [Compilation](./architecture/compilation.md)
     - [Files](./architecture/files.md)

src/doc/contrib/src/architecture/files.md

@@ -1,25 +1,3 @@
 # Files
 
 See [nightly docs](https://doc.rust-lang.org/nightly/nightly-rustc/cargo/index.html)
-
-## Filesystems
-
-Cargo tends to get run on a very wide array of file systems. Different file
-systems can have a wide range of capabilities, and Cargo should strive to do
-its best to handle them. Some examples of issues to deal with:
-
-* Not all file systems support locking. Cargo tries to detect if locking is
-  supported, and if not, will ignore lock errors. This isn't ideal, but it is
-  difficult to deal with.
-* The [`fs::canonicalize`] function doesn't work on all file systems
-  (particularly some Windows file systems). If that function is used, there
-  should be a fallback if it fails. This function will also return `\\?\`
-  style paths on Windows, which can have some issues (such as some tools not
-  supporting them, or having issues with relative paths).
-* Timestamps can be unreliable. The [`fingerprint`] module has a deeper
-  discussion of this. One example is that Docker cache layers will erase the
-  fractional part of the time stamp.
-* Symlinks are not always supported, particularly on Windows.
-
-[`fingerprint`]: https://github.com/rust-lang/cargo/blob/master/src/cargo/core/compiler/fingerprint.rs
-[`fs::canonicalize`]: https://doc.rust-lang.org/std/fs/fn.canonicalize.html

src/doc/contrib/src/architecture/filesystem.md

@@ -0,0 +1 @@
+# Filesystem

src/doc/contrib/src/implementation/architecture.md

@@ -0,0 +1,5 @@
+# Architecture Overview
+
+See the
+[nightly docs](https://doc.rust-lang.org/nightly/nightly-rustc/cargo/index.html)
+for an overview of `cargo`s architecture and links out to further details.

src/doc/contrib/src/architecture/console.md → src/doc/contrib/src/implementation/console.md

@@ -55,28 +55,4 @@ Some guidelines for Cargo's output:
   and use multiple sentences. This should probably be improved sometime in the
   future to be more structured.
 
-## Debug logging
-
-Cargo uses the [`env_logger`] crate to display debug log messages. The
-`CARGO_LOG` environment variable can be set to enable debug logging, with a
-value such as `trace`, `debug`, or `warn`. It also supports filtering for
-specific modules. Feel free to use the standard [`log`] macros to help with
-diagnosing problems.
-
-```sh
-# Outputs all logs with levels debug and higher
-CARGO_LOG=debug cargo generate-lockfile
-
-# Don't forget that you can filter by module as well
-CARGO_LOG=cargo::core::resolver=trace cargo generate-lockfile
-
-# This will print lots of info about the download process. `trace` prints even more.
-CARGO_HTTP_DEBUG=true CARGO_LOG=cargo::ops::registry=debug cargo fetch
-
-# This is an important command for diagnosing fingerprint issues.
-CARGO_LOG=cargo::core::compiler::fingerprint=trace cargo build
-```
-
-[`env_logger`]: https://docs.rs/env_logger
-[`log`]: https://docs.rs/log
 [`anyhow`]: https://docs.rs/anyhow

src/doc/contrib/src/implementation/debugging.md

@@ -0,0 +1,26 @@
+# Debugging
+
+## Logging
+
+Cargo uses the [`env_logger`] crate to display debug log messages. The
+`CARGO_LOG` environment variable can be set to enable debug logging, with a
+value such as `trace`, `debug`, or `warn`. It also supports filtering for
+specific modules. Feel free to use the standard [`log`] macros to help with
+diagnosing problems.
+
+```sh
+# Outputs all logs with levels debug and higher
+CARGO_LOG=debug cargo generate-lockfile
+
+# Don't forget that you can filter by module as well
+CARGO_LOG=cargo::core::resolver=trace cargo generate-lockfile
+
+# This will print lots of info about the download process. `trace` prints even more.
+CARGO_HTTP_DEBUG=true CARGO_LOG=cargo::ops::registry=debug cargo fetch
+
+# This is an important command for diagnosing fingerprint issues.
+CARGO_LOG=cargo::core::compiler::fingerprint=trace cargo build
+```
+
+[`env_logger`]: https://docs.rs/env_logger
+[`log`]: https://docs.rs/log

src/doc/contrib/src/implementation/filesystem.md

@@ -0,0 +1,21 @@
+# Filesystem
+
+Cargo tends to get run on a very wide array of file systems. Different file
+systems can have a wide range of capabilities, and Cargo should strive to do
+its best to handle them. Some examples of issues to deal with:
+
+* Not all file systems support locking. Cargo tries to detect if locking is
+  supported, and if not, will ignore lock errors. This isn't ideal, but it is
+  difficult to deal with.
+* The [`fs::canonicalize`] function doesn't work on all file systems
+  (particularly some Windows file systems). If that function is used, there
+  should be a fallback if it fails. This function will also return `\\?\`
+  style paths on Windows, which can have some issues (such as some tools not
+  supporting them, or having issues with relative paths).
+* Timestamps can be unreliable. The [`fingerprint`] module has a deeper
+  discussion of this. One example is that Docker cache layers will erase the
+  fractional part of the time stamp.
+* Symlinks are not always supported, particularly on Windows.
+
+[`fingerprint`]: https://github.com/rust-lang/cargo/blob/master/src/cargo/core/compiler/fingerprint.rs
+[`fs::canonicalize`]: https://doc.rust-lang.org/std/fs/fn.canonicalize.html

src/doc/contrib/src/implementation/index.md

@@ -0,0 +1,6 @@
+# Implementing a Change
+
+This chapter gives an overview of what you need to know in making a change to cargo.
+
+If you feel something is missing that would help you, feel free to ask on
+[Zulip](https://rust-lang.zulipchat.com/#narrow/stream/246057-t-cargo).

src/doc/contrib/src/architecture/subcommands.md → src/doc/contrib/src/implementation/subcommands.md

@@ -1,4 +1,4 @@
-# SubCommands
+# New Subcommands
 
 Cargo is a single binary composed of a set of [`clap`] subcommands. All
 subcommands live in [`src/bin/cargo/commands`] directory.