// Copyright 2018-2019 Parity Technologies (UK) Ltd.
// This file is part of ink!.
//
// ink! is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// ink! is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with ink!. If not, see .
use crate::cmd::{
CommandError as Error,
Result,
};
use cargo_metadata::MetadataCommand;
use parity_wasm::elements::{
External,
MemoryType,
Module,
Section,
};
use std::{
io::{
self,
Write,
},
path::PathBuf,
process::Command,
};
/// This is the maximum number of pages available for a contract to allocate.
const MAX_MEMORY_PAGES: u32 = 16;
/// Relevant metadata obtained from Cargo.toml.
pub struct CrateMetadata {
original_wasm: PathBuf,
dest_wasm: PathBuf,
}
impl CrateMetadata {
/// Get the path of the wasm destination file
pub fn dest_wasm(self) -> PathBuf {
self.dest_wasm
}
}
/// Parses the contract manifest and returns relevant metadata.
pub fn collect_crate_metadata() -> Result {
let metadata = MetadataCommand::new().exec()?;
let root_package_id = metadata
.resolve
.and_then(|resolve| resolve.root)
.ok_or_else(|| Error::Other("Cannot infer the root project id".to_string()))?;
// Find the root package by id in the list of packages. It is logical error if the root
// package is not found in the list.
let root_package = metadata
.packages
.iter()
.find(|package| package.id == root_package_id)
.expect("The package is not found in the `cargo metadata` output");
// Normalize the package name.
let package_name = root_package.name.replace("-", "_");
// {target_dir}/wasm32-unknown-unknown/release/{package_name}.wasm
let mut original_wasm = metadata.target_directory.clone();
original_wasm.push("wasm32-unknown-unknown");
original_wasm.push("release");
original_wasm.push(package_name.clone());
original_wasm.set_extension("wasm");
// {target_dir}/{package_name}.wasm
let mut dest_wasm = metadata.target_directory.clone();
dest_wasm.push(package_name);
dest_wasm.set_extension("wasm");
Ok(CrateMetadata {
original_wasm,
dest_wasm,
})
}
/// Invokes `cargo build` in the current directory.
///
/// Currently it assumes that user wants to use `+nightly`.
fn build_cargo_project() -> Result<()> {
// We also assume that the user uses +nightly.
let output = Command::new("cargo")
.args(&[
"+nightly",
"build",
"--no-default-features",
"--release",
"--target=wasm32-unknown-unknown",
"--verbose",
])
.output()?;
if !output.status.success() {
// Dump the output streams produced by cargo into the stdout/stderr.
io::stdout().write_all(&output.stdout)?;
io::stderr().write_all(&output.stderr)?;
return Err(Error::BuildFailed)
}
Ok(())
}
/// Ensures the wasm memory import of a given module has the maximum number of pages.
///
/// Iterates over the import section, finds the memory import entry if any and adjusts the maximum
/// limit.
fn ensure_maximum_memory_pages(
module: &mut Module,
maximum_allowed_pages: u32,
) -> Result<()> {
let mem_ty = module
.import_section_mut()
.and_then(|section| {
section.entries_mut()
.iter_mut()
.find_map(|entry| {
match entry.external_mut() {
External::Memory(ref mut mem_ty) => Some(mem_ty),
_ => None,
}
})
})
.ok_or_else(||
Error::Other(
"Memory import is not found. Is --import-memory specified in the linker args".to_string()
)
)?;
if let Some(requested_maximum) = mem_ty.limits().maximum() {
// The module already has maximum, check if it is within the limit bail out.
if requested_maximum > maximum_allowed_pages {
return Err(
Error::Other(
format!(
"The wasm module requires {} pages. The maximum allowed number of pages is {}",
requested_maximum,
maximum_allowed_pages,
)
)
);
}
} else {
let initial = mem_ty.limits().initial();
*mem_ty = MemoryType::new(initial, Some(MAX_MEMORY_PAGES));
}
Ok(())
}
/// Strips all custom sections.
///
/// Presently all custom sections are not required so they can be stripped safely.
fn strip_custom_sections(module: &mut Module) {
module.sections_mut().retain(|section| match section {
Section::Custom(_) => false,
Section::Name(_) => false,
Section::Reloc(_) => false,
_ => true,
});
}
/// Performs required post-processing steps on the wasm artifact.
fn post_process_wasm(crate_metadata: &CrateMetadata) -> Result<()> {
// Deserialize wasm module from a file.
let mut module = parity_wasm::deserialize_file(&crate_metadata.original_wasm)?;
// Perform optimization.
//
// In practice only tree-shaking is performed, i.e transitively removing all symbols that are
// NOT used by the specified entrypoints.
pwasm_utils::optimize(&mut module, ["call", "deploy"].to_vec())?;
ensure_maximum_memory_pages(&mut module, MAX_MEMORY_PAGES)?;
strip_custom_sections(&mut module);
parity_wasm::serialize_to_file(&crate_metadata.dest_wasm, module)?;
Ok(())
}
/// Executes build of the smart-contract which produces a wasm binary that is ready for deploying.
///
/// It does so by invoking build by cargo and then post processing the final binary.
pub(crate) fn execute_build() -> Result {
println!(" [1/3] Collecting crate metadata");
let crate_metadata = collect_crate_metadata()?;
println!(" [2/3] Building cargo project");
build_cargo_project()?;
println!(" [3/3] Post processing wasm file");
post_process_wasm(&crate_metadata)?;
Ok(format!(
"Your contract is ready.\nYou can find it here:\n{}",
crate_metadata.dest_wasm.display()
))
}
#[cfg(test)]
mod tests {
use super::*;
use crate::{
cmd::execute_new,
AbstractionLayer,
};
use tempfile::TempDir;
use std::env;
fn with_tmp_dir(f: F) {
let original_cwd = env::current_dir().expect("failed to get current working directory");
let tmp_dir = TempDir::new().expect("temporary directory creation failed");
env::set_current_dir(tmp_dir.path()).expect("setting the current dir to temp failed");
f();
env::set_current_dir(original_cwd).expect("restoring cwd failed");
}
#[cfg(feature="test-ci-only")]
#[test]
fn build_template() {
with_tmp_dir(|| {
execute_new(AbstractionLayer::Lang, "new_project").expect("new project creation failed");
env::set_current_dir("./new_project").expect("cwd to new_project failed");
execute_build().expect("build failed");
});
}
}