Files
biguint
chain_spec_builder
compact
fixed_point
fork_tree
frame_benchmarking
frame_benchmarking_cli
frame_election_provider_support
frame_executive
frame_metadata
frame_support
frame_support_procedural
frame_support_procedural_tools
frame_support_procedural_tools_derive
frame_support_test
frame_support_test_pallet
frame_system
frame_system_benchmarking
frame_system_rpc_runtime_api
frame_try_runtime
multiply_by_rational
node_bench
node_browser_testing
node_cli
node_executor
node_inspect
node_primitives
node_rpc
node_rpc_client
node_runtime
node_template
node_template_runtime
node_testing
normalize
pallet_assets
pallet_atomic_swap
pallet_aura
pallet_authority_discovery
pallet_authorship
pallet_babe
pallet_balances
pallet_bounties
pallet_collective
pallet_contracts
pallet_contracts_primitives
pallet_contracts_proc_macro
pallet_contracts_rpc
pallet_contracts_rpc_runtime_api
pallet_democracy
pallet_election_provider_multi_phase
pallet_elections
pallet_elections_phragmen
pallet_example
pallet_example_offchain_worker
pallet_example_parallel
pallet_gilt
pallet_grandpa
pallet_identity
pallet_im_online
pallet_indices
pallet_lottery
pallet_membership
pallet_mmr
pallet_mmr_primitives
pallet_mmr_rpc
pallet_multisig
pallet_nicks
pallet_node_authorization
pallet_offences
pallet_offences_benchmarking
pallet_proxy
pallet_randomness_collective_flip
pallet_recovery
pallet_scheduler
pallet_scored_pool
pallet_session
pallet_session_benchmarking
pallet_society
pallet_staking
pallet_staking_reward_curve
pallet_staking_reward_fn
pallet_sudo
pallet_template
pallet_timestamp
pallet_tips
pallet_transaction_payment
pallet_transaction_payment_rpc
pallet_transaction_payment_rpc_runtime_api
pallet_transaction_storage
pallet_treasury
pallet_uniques
pallet_utility
pallet_vesting
per_thing_rational
phragmen_balancing
phragmen_pjr
phragmms_balancing
reduce
remote_externalities
sc_allocator
sc_authority_discovery
sc_basic_authorship
sc_block_builder
sc_chain_spec
sc_chain_spec_derive
sc_cli
sc_client_api
sc_client_db
sc_consensus
sc_consensus_aura
sc_consensus_babe
sc_consensus_babe_rpc
sc_consensus_epochs
sc_consensus_manual_seal
sc_consensus_pow
sc_consensus_slots
sc_consensus_uncles
sc_executor
sc_executor_common
sc_executor_wasmi
sc_executor_wasmtime
sc_finality_grandpa
sc_finality_grandpa_rpc
sc_informant
sc_keystore
sc_light
sc_network
sc_network_gossip
sc_network_test
sc_offchain
sc_peerset
sc_proposer_metrics
sc_rpc
sc_rpc_api
sc_rpc_server
sc_runtime_test
sc_service
sc_service_test
sc_state_db
sc_sync_state_rpc
sc_telemetry
sc_tracing
sc_tracing_proc_macro
sc_transaction_pool
sc_transaction_pool_api
sp_api
sp_api_proc_macro
sp_application_crypto
sp_application_crypto_test
sp_arithmetic
sp_authority_discovery
sp_authorship
sp_block_builder
sp_blockchain
sp_consensus
sp_consensus_aura
sp_consensus_babe
sp_consensus_pow
sp_consensus_slots
sp_consensus_vrf
sp_core
sp_database
sp_debug_derive
sp_externalities
sp_finality_grandpa
sp_inherents
sp_io
sp_keyring
sp_keystore
sp_maybe_compressed_blob
sp_npos_elections
sp_npos_elections_solution_type
sp_offchain
sp_panic_handler
sp_rpc
sp_runtime
sp_runtime_interface
sp_runtime_interface_proc_macro
sp_runtime_interface_test
sp_runtime_interface_test_wasm
sp_runtime_interface_test_wasm_deprecated
sp_sandbox
sp_serializer
sp_session
sp_staking
sp_state_machine
sp_std
sp_storage
sp_tasks
sp_test_primitives
sp_timestamp
sp_tracing
sp_transaction_pool
sp_transaction_storage_proof
sp_trie
sp_utils
sp_version
sp_version_proc_macro
sp_wasm_interface
subkey
substrate
substrate_browser_utils
substrate_build_script_utils
substrate_frame_cli
substrate_frame_rpc_support
substrate_frame_rpc_system
substrate_prometheus_endpoint
substrate_test_client
substrate_test_runtime
substrate_test_runtime_client
substrate_test_runtime_transaction_pool
substrate_test_utils
substrate_test_utils_derive
substrate_test_utils_test_crate
substrate_wasm_builder
test_runner
test_runner_example
try_runtime_cli
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
// This file is part of Substrate.

// Copyright (C) 2019-2021 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// 	http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! # Wasm builder is a utility for building a project as a Wasm binary
//!
//! The Wasm builder is a tool that integrates the process of building the WASM binary of your
//! project into the main `cargo` build process.
//!
//! ## Project setup
//!
//! A project that should be compiled as a Wasm binary needs to:
//!
//! 1. Add a `build.rs` file.
//! 2. Add `wasm-builder` as dependency into `build-dependencies`.
//!
//! The `build.rs` file needs to contain the following code:
//!
//! ```no_run
//! use substrate_wasm_builder::WasmBuilder;
//!
//! fn main() {
//!     WasmBuilder::new()
//!         // Tell the builder to build the project (crate) this `build.rs` is part of.
//!         .with_current_project()
//!         // Make sure to export the `heap_base` global, this is required by Substrate
//!         .export_heap_base()
//!         // Build the Wasm file so that it imports the memory (need to be provided by at instantiation)
//!         .import_memory()
//!         // Build it.
//!         .build()
//! }
//! ```
//!
//! As the final step, you need to add the following to your project:
//!
//! ```ignore
//! include!(concat!(env!("OUT_DIR"), "/wasm_binary.rs"));
//! ```
//!
//! This will include the generated Wasm binary as two constants `WASM_BINARY` and
//! `WASM_BINARY_BLOATY`. The former is a compact Wasm binary and the latter is the Wasm binary as
//! being generated by the compiler. Both variables have `Option<&'static [u8]>` as type.
//!
//! ### Feature
//!
//! Wasm builder supports to enable cargo features while building the Wasm binary. By default it
//! will enable all features in the wasm build that are enabled for the native build except the
//! `default` and `std` features. Besides that, wasm builder supports the special `runtime-wasm`
//! feature. This `runtime-wasm` feature will be enabled by the wasm builder when it compiles the
//! Wasm binary. If this feature is not present, it will not be enabled.
//!
//! ## Environment variables
//!
//! By using environment variables, you can configure which Wasm binaries are built and how:
//!
//! - `SKIP_WASM_BUILD` - Skips building any Wasm binary. This is useful when only native should be
//!   recompiled. If this is the first run and there doesn't exist a Wasm binary, this will set both
//!   variables to `None`.
//! - `WASM_BUILD_TYPE` - Sets the build type for building Wasm binaries. Supported values are
//!   `release` or `debug`. By default the build type is equal to the build type used by the main
//!   build.
//! - `FORCE_WASM_BUILD` - Can be set to force a Wasm build. On subsequent calls the value of the
//!   variable needs to change. As wasm-builder instructs `cargo` to watch for file changes this
//!   environment variable should only be required in certain circumstances.
//! - `WASM_BUILD_RUSTFLAGS` - Extend `RUSTFLAGS` given to `cargo build` while building the wasm
//!   binary.
//! - `WASM_BUILD_NO_COLOR` - Disable color output of the wasm build.
//! - `WASM_TARGET_DIRECTORY` - Will copy any build Wasm binary to the given directory. The path
//!   needs to be absolute.
//! - `WASM_BUILD_TOOLCHAIN` - The toolchain that should be used to build the Wasm binaries. The
//!   format needs to be the same as used by cargo, e.g. `nightly-2020-02-20`.
//!
//! Each project can be skipped individually by using the environment variable
//! `SKIP_PROJECT_NAME_WASM_BUILD`. Where `PROJECT_NAME` needs to be replaced by the name of the
//! cargo project, e.g. `node-runtime` will be `NODE_RUNTIME`.
//!
//! ## Prerequisites:
//!
//! Wasm builder requires the following prerequisites for building the Wasm binary:
//!
//! - rust nightly + `wasm32-unknown-unknown` toolchain
//!
//! If a specific rust nightly is installed with `rustup`, it is important that the wasm target is
//! installed as well. For example if installing the rust nightly from 20.02.2020 using `rustup
//! install nightly-2020-02-20`, the wasm target needs to be installed as well `rustup target add
//! wasm32-unknown-unknown --toolchain nightly-2020-02-20`.

use std::{
	env, fs,
	io::BufRead,
	path::{Path, PathBuf},
	process::Command,
};

mod builder;
mod prerequisites;
mod wasm_project;

pub use builder::{WasmBuilder, WasmBuilderSelectProject};

/// Environment variable that tells us to skip building the wasm binary.
const SKIP_BUILD_ENV: &str = "SKIP_WASM_BUILD";

/// Environment variable to force a certain build type when building the wasm binary.
/// Expects "debug" or "release" as value.
///
/// By default the WASM binary uses the same build type as the main cargo build.
const WASM_BUILD_TYPE_ENV: &str = "WASM_BUILD_TYPE";

/// Environment variable to extend the `RUSTFLAGS` variable given to the wasm build.
const WASM_BUILD_RUSTFLAGS_ENV: &str = "WASM_BUILD_RUSTFLAGS";

/// Environment variable to set the target directory to copy the final wasm binary.
///
/// The directory needs to be an absolute path.
const WASM_TARGET_DIRECTORY: &str = "WASM_TARGET_DIRECTORY";

/// Environment variable to disable color output of the wasm build.
const WASM_BUILD_NO_COLOR: &str = "WASM_BUILD_NO_COLOR";

/// Environment variable to set the toolchain used to compile the wasm binary.
const WASM_BUILD_TOOLCHAIN: &str = "WASM_BUILD_TOOLCHAIN";

/// Environment variable that makes sure the WASM build is triggered.
const FORCE_WASM_BUILD_ENV: &str = "FORCE_WASM_BUILD";

/// Write to the given `file` if the `content` is different.
fn write_file_if_changed(file: impl AsRef<Path>, content: impl AsRef<str>) {
	if fs::read_to_string(file.as_ref()).ok().as_deref() != Some(content.as_ref()) {
		fs::write(file.as_ref(), content.as_ref())
			.unwrap_or_else(|_| panic!("Writing `{}` can not fail!", file.as_ref().display()));
	}
}

/// Copy `src` to `dst` if the `dst` does not exist or is different.
fn copy_file_if_changed(src: PathBuf, dst: PathBuf) {
	let src_file = fs::read_to_string(&src).ok();
	let dst_file = fs::read_to_string(&dst).ok();

	if src_file != dst_file {
		fs::copy(&src, &dst).unwrap_or_else(|_| {
			panic!("Copying `{}` to `{}` can not fail; qed", src.display(), dst.display())
		});
	}
}

/// Get a cargo command that compiles with nightly
fn get_nightly_cargo() -> CargoCommand {
	let env_cargo =
		CargoCommand::new(&env::var("CARGO").expect("`CARGO` env variable is always set by cargo"));
	let default_cargo = CargoCommand::new("cargo");
	let rustup_run_nightly = CargoCommand::new_with_args("rustup", &["run", "nightly", "cargo"]);
	let wasm_toolchain = env::var(WASM_BUILD_TOOLCHAIN).ok();

	// First check if the user requested a specific toolchain
	if let Some(cmd) = wasm_toolchain.and_then(|t| get_rustup_nightly(Some(t))) {
		cmd
	} else if env_cargo.is_nightly() {
		env_cargo
	} else if default_cargo.is_nightly() {
		default_cargo
	} else if rustup_run_nightly.is_nightly() {
		rustup_run_nightly
	} else {
		// If no command before provided us with a nightly compiler, we try to search one
		// with rustup. If that fails as well, we return the default cargo and let the prequisities
		// check fail.
		get_rustup_nightly(None).unwrap_or(default_cargo)
	}
}

/// Get a nightly from rustup. If `selected` is `Some(_)`, a `CargoCommand` using the given
/// nightly is returned.
fn get_rustup_nightly(selected: Option<String>) -> Option<CargoCommand> {
	let host = format!("-{}", env::var("HOST").expect("`HOST` is always set by cargo"));

	let version = match selected {
		Some(selected) => selected,
		None => {
			let output = Command::new("rustup").args(&["toolchain", "list"]).output().ok()?.stdout;
			let lines = output.as_slice().lines();

			let mut latest_nightly = None;
			for line in lines.filter_map(|l| l.ok()) {
				if line.starts_with("nightly-") && line.ends_with(&host) {
					// Rustup prints them sorted
					latest_nightly = Some(line.clone());
				}
			}

			latest_nightly?.trim_end_matches(&host).into()
		},
	};

	Some(CargoCommand::new_with_args("rustup", &["run", &version, "cargo"]))
}

/// Wraps a specific command which represents a cargo invocation.
#[derive(Debug)]
struct CargoCommand {
	program: String,
	args: Vec<String>,
}

impl CargoCommand {
	fn new(program: &str) -> Self {
		CargoCommand { program: program.into(), args: Vec::new() }
	}

	fn new_with_args(program: &str, args: &[&str]) -> Self {
		CargoCommand {
			program: program.into(),
			args: args.iter().map(ToString::to_string).collect(),
		}
	}

	fn command(&self) -> Command {
		let mut cmd = Command::new(&self.program);
		cmd.args(&self.args);
		cmd
	}

	/// Check if the supplied cargo command is a nightly version
	fn is_nightly(&self) -> bool {
		// `RUSTC_BOOTSTRAP` tells a stable compiler to behave like a nightly. So, when this env
		// variable is set, we can assume that whatever rust compiler we have, it is a nightly
		// compiler. For "more" information, see:
		// https://github.com/rust-lang/rust/blob/fa0f7d0080d8e7e9eb20aa9cbf8013f96c81287f/src/libsyntax/feature_gate/check.rs#L891
		env::var("RUSTC_BOOTSTRAP").is_ok() ||
			self.command()
				.arg("--version")
				.output()
				.map_err(|_| ())
				.and_then(|o| String::from_utf8(o.stdout).map_err(|_| ()))
				.unwrap_or_default()
				.contains("-nightly")
	}
}

/// Wraps a [`CargoCommand`] and the version of `rustc` the cargo command uses.
struct CargoCommandVersioned {
	command: CargoCommand,
	version: String,
}

impl CargoCommandVersioned {
	fn new(command: CargoCommand, version: String) -> Self {
		Self { command, version }
	}

	/// Returns the `rustc` version.
	fn rustc_version(&self) -> &str {
		&self.version
	}
}

impl std::ops::Deref for CargoCommandVersioned {
	type Target = CargoCommand;

	fn deref(&self) -> &CargoCommand {
		&self.command
	}
}

/// Returns `true` when color output is enabled.
fn color_output_enabled() -> bool {
	env::var(crate::WASM_BUILD_NO_COLOR).is_err()
}