Use alloc for no_std builds

Replace std structs with alloc equivalents to support no_std builds

f use prelude::* credit @devrandom

Author: GeneFerneau

lightning/src/chain/chainmonitor.rs

@@ -37,6 +37,7 @@ use util::logger::Logger;
 use util::events;
 use util::events::EventHandler;
 
+use prelude::*;
 use std::collections::{HashMap, hash_map};
 use std::sync::RwLock;
 use core::ops::Deref;
@@ -143,7 +144,7 @@ where C::Target: chain::Filter,
 	#[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
 	pub fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
 		use util::events::EventsProvider;
-		let events = std::cell::RefCell::new(Vec::new());
+		let events = core::cell::RefCell::new(Vec::new());
 		let event_handler = |event| events.borrow_mut().push(event);
 		self.process_pending_events(&event_handler);
 		events.into_inner()

lightning/src/chain/channelmonitor.rs

@@ -51,6 +51,7 @@ use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48};
 use util::byte_utils;
 use util::events::Event;
 
+use prelude::*;
 use std::collections::{HashMap, HashSet};
 use core::{cmp, mem};
 use std::io::Error;
@@ -2911,6 +2912,7 @@ mod tests {
 	use bitcoin::secp256k1::Secp256k1;
 	use std::sync::{Arc, Mutex};
 	use chain::keysinterface::InMemorySigner;
+	use prelude::*;
 
 	#[test]
 	fn test_prune_preimages() {

lightning/src/chain/keysinterface.rs

@@ -37,6 +37,7 @@ use ln::chan_utils;
 use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction};
 use ln::msgs::UnsignedChannelAnnouncement;
 
+use prelude::*;
 use std::collections::HashSet;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use std::io::Error;

lightning/src/chain/mod.rs

@@ -18,6 +18,8 @@ use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitor
 use chain::keysinterface::Sign;
 use chain::transaction::{OutPoint, TransactionData};
 
+use prelude::*;
+
 pub mod chaininterface;
 pub mod chainmonitor;
 pub mod channelmonitor;

lightning/src/chain/onchaintx.rs

@@ -32,6 +32,7 @@ use util::logger::Logger;
 use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter};
 use util::byte_utils;
 
+use prelude::*;
 use std::collections::HashMap;
 use core::cmp;
 use core::ops::Deref;

lightning/src/chain/package.rs

@@ -31,9 +31,9 @@ use util::byte_utils;
 use util::logger::Logger;
 use util::ser::{Readable, Writer, Writeable};
 
-use std::cmp;
-use std::mem;
-use std::ops::Deref;
+use core::cmp;
+use core::mem;
+use core::ops::Deref;
 
 const MAX_ALLOC_SIZE: usize = 64*1024;
 

lightning/src/lib.rs

@@ -31,6 +31,7 @@
 #![cfg_attr(all(any(test, feature = "_test_utils"), feature = "unstable"), feature(test))]
 #[cfg(all(any(test, feature = "_test_utils"), feature = "unstable"))] extern crate test;
 
+extern crate alloc;
 extern crate bitcoin;
 extern crate core;
 #[cfg(any(test, feature = "_test_utils"))] extern crate hex;
@@ -41,3 +42,7 @@ pub mod util;
 pub mod chain;
 pub mod ln;
 pub mod routing;
+
+mod prelude {
+	pub use alloc::{vec, vec::Vec, string::String};
+}

lightning/src/ln/chan_utils.rs

@@ -31,6 +31,7 @@ use bitcoin::secp256k1::{Secp256k1, Signature, Message};
 use bitcoin::secp256k1::Error as SecpError;
 use bitcoin::secp256k1;
 
+use prelude::*;
 use core::cmp;
 use ln::chan_utils;
 use util::transaction_utils::sort_outputs;
@@ -1235,6 +1236,7 @@ fn script_for_p2wpkh(key: &PublicKey) -> Script {
 mod tests {
 	use super::CounterpartyCommitmentSecrets;
 	use hex;
+	use prelude::*;
 
 	#[test]
 	fn test_per_commitment_storage() {

lightning/src/ln/chanmon_update_fail_tests.rs

@@ -38,6 +38,7 @@ use ln::functional_test_utils::*;
 
 use util::test_utils;
 
+use prelude::*;
 use std::collections::HashMap;
 
 // If persister_fail is true, we have the persister return a PermanentFailure

lightning/src/ln/channel.rs

@@ -40,6 +40,7 @@ use util::errors::APIError;
 use util::config::{UserConfig,ChannelConfig};
 use util::scid_utils::scid_from_parts;
 
+use prelude::*;
 use core::{cmp,mem,fmt};
 use core::ops::Deref;
 #[cfg(any(test, feature = "fuzztarget"))]
@@ -4928,6 +4929,7 @@ mod tests {
 	use bitcoin::hashes::Hash;
 	use bitcoin::hash_types::{Txid, WPubkeyHash};
 	use std::sync::Arc;
+	use prelude::*;
 
 	struct TestFeeEstimator {
 		fee_est: u32