Generate docs with features for docs.rs

Enable generating docs using --all-features or --features="std" where
applicable. Additionally, use doc_auto_cfg to tag items requiring a
feature.

https://doc.rust-lang.org/nightly/rustdoc/unstable-features.html#doc_auto_cfg-automatically-generate-doccfg

This requires building with nightly, which is what is used by docs.rs.

https://docs.rs/about/builds

To test locally, use:

RUSTDOCFLAGS="--cfg docsrs" cargo +nightly doc ...

Author: jkczyz

lightning-background-processor/Cargo.toml

@@ -9,6 +9,10 @@ Utilities to perform required background tasks for Rust Lightning.
 """
 edition = "2018"
 
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
 [dependencies]
 bitcoin = "0.27"
 lightning = { version = "0.0.104", path = "../lightning", features = ["std"] }

lightning-background-processor/src/lib.rs

@@ -6,6 +6,8 @@
 #![deny(missing_docs)]
 #![deny(unsafe_code)]
 
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
 #[macro_use] extern crate lightning;
 
 use lightning::chain;

lightning-block-sync/Cargo.toml

@@ -9,6 +9,10 @@ Utilities to fetch the chain data from a block source and feed them into Rust Li
 """
 edition = "2018"
 
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
 [features]
 rest-client = [ "serde", "serde_json", "chunked_transfer" ]
 rpc-client = [ "serde", "serde_json", "chunked_transfer" ]

lightning-block-sync/src/lib.rs

@@ -17,6 +17,8 @@
 #![deny(missing_docs)]
 #![deny(unsafe_code)]
 
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
 #[cfg(any(feature = "rest-client", feature = "rpc-client"))]
 pub mod http;
 

lightning-invoice/Cargo.toml

@@ -8,6 +8,10 @@ license = "MIT OR Apache-2.0"
 keywords = [ "lightning", "bitcoin", "invoice", "BOLT11" ]
 readme = "README.md"
 
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
 [features]
 default = ["std"]
 no-std = ["hashbrown", "lightning/no-std", "core2/alloc"]

lightning-invoice/src/lib.rs

@@ -5,6 +5,8 @@
 #![deny(unused_mut)]
 #![deny(broken_intra_doc_links)]
 
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
 #![cfg_attr(feature = "strict", deny(warnings))]
 #![cfg_attr(all(not(feature = "std"), not(test)), no_std)]
 

lightning-net-tokio/Cargo.toml

@@ -10,6 +10,10 @@ For Rust-Lightning clients which wish to make direct connections to Lightning P2
 """
 edition = "2018"
 
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
 [dependencies]
 bitcoin = "0.27"
 lightning = { version = "0.0.104", path = "../lightning" }

lightning-net-tokio/src/lib.rs

@@ -69,6 +69,8 @@
 #![deny(broken_intra_doc_links)]
 #![deny(missing_docs)]
 
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
 use bitcoin::secp256k1::key::PublicKey;
 
 use tokio::net::TcpStream;

lightning-persister/Cargo.toml

@@ -8,6 +8,10 @@ description = """
 Utilities to manage Rust-Lightning channel data persistence and retrieval.
 """
 
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
 [features]
 unstable = ["lightning/unstable"]
 

lightning-persister/src/lib.rs

@@ -3,6 +3,8 @@
 #![deny(broken_intra_doc_links)]
 #![deny(missing_docs)]
 
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
 #![cfg_attr(all(test, feature = "unstable"), feature(test))]
 #[cfg(all(test, feature = "unstable"))] extern crate test;
 

lightning/Cargo.toml

@@ -10,6 +10,10 @@ Does most of the hard work, without implying a specific runtime, requiring clien
 Still missing tons of error-handling. See GitHub issues for suggested projects if you want to contribute. Don't have to bother telling you not to use this for anything serious, because you'd have to build a client around it to even try.
 """
 
+[package.metadata.docs.rs]
+features = ["std"]
+rustdoc-args = ["--cfg", "docsrs"]
+
 [features]
 fuzztarget = ["bitcoin/fuzztarget", "regex"]
 # Internal test utilities exposed to other repo crates

lightning/src/lib.rs

@@ -28,6 +28,8 @@
 #![allow(bare_trait_objects)]
 #![allow(ellipsis_inclusive_range_patterns)]
 
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
 #![cfg_attr(all(not(feature = "std"), not(test)), no_std)]
 
 #![cfg_attr(all(any(test, feature = "_test_utils"), feature = "unstable"), feature(test))]