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|
fn main() -> anyhow::Result<()> {
component::generate_static_api_tests()?;
Ok(())
}
mod component {
use anyhow::{anyhow, Context, Error, Result};
use arbitrary::Unstructured;
use component_fuzz_util::{Declarations, TestCase, Type, MAX_TYPE_DEPTH};
use proc_macro2::TokenStream;
use quote::quote;
use rand::rngs::StdRng;
use rand::{Rng, SeedableRng};
use std::env;
use std::fmt::Write;
use std::fs;
use std::iter;
use std::path::PathBuf;
use std::process::Command;
pub fn generate_static_api_tests() -> Result<()> {
println!("cargo:rerun-if-changed=build.rs");
let out_dir = PathBuf::from(
env::var_os("OUT_DIR").expect("The OUT_DIR environment variable must be set"),
);
let mut out = String::new();
write_static_api_tests(&mut out)?;
let output = out_dir.join("static_component_api.rs");
fs::write(&output, out)?;
drop(Command::new("rustfmt").arg(&output).status());
Ok(())
}
fn write_static_api_tests(out: &mut String) -> Result<()> {
let seed = if let Ok(seed) = env::var("WASMTIME_FUZZ_SEED") {
seed.parse::<u64>()
.with_context(|| anyhow!("expected u64 in WASMTIME_FUZZ_SEED"))?
} else {
StdRng::from_entropy().gen()
};
eprintln!(
"using seed {seed} (set WASMTIME_FUZZ_SEED={seed} in your environment to reproduce)"
);
let mut rng = StdRng::seed_from_u64(seed);
const TYPE_COUNT: usize = 50;
const MAX_ARITY: u32 = 5;
const TEST_CASE_COUNT: usize = 100;
let mut type_fuel = 1000;
let mut types = Vec::new();
let name_counter = &mut 0;
let mut declarations = TokenStream::new();
let mut tests = TokenStream::new();
// First generate a set of type to select from.
for _ in 0..TYPE_COUNT {
let ty = gen(&mut rng, |u| {
// Only discount fuel if the generation was successful,
// otherwise we'll get more random data and try again.
let mut fuel = type_fuel;
let ret = Type::generate(u, MAX_TYPE_DEPTH, &mut fuel);
if ret.is_ok() {
type_fuel = fuel;
}
ret
})?;
let name = component_fuzz_util::rust_type(&ty, name_counter, &mut declarations);
types.push((name, ty));
}
// Next generate a set of static API test cases driven by the above
// types.
for index in 0..TEST_CASE_COUNT {
let (case, rust_params, rust_results) = gen(&mut rng, |u| {
let mut params = Vec::new();
let mut results = Vec::new();
let mut rust_params = TokenStream::new();
let mut rust_results = TokenStream::new();
for _ in 0..u.int_in_range(0..=MAX_ARITY)? {
let (name, ty) = u.choose(&types)?;
params.push(ty);
rust_params.extend(name.clone());
rust_params.extend(quote!(,));
}
for _ in 0..u.int_in_range(0..=MAX_ARITY)? {
let (name, ty) = u.choose(&types)?;
results.push(ty);
rust_results.extend(name.clone());
rust_results.extend(quote!(,));
}
let case = TestCase {
params,
results,
encoding1: u.arbitrary()?,
encoding2: u.arbitrary()?,
};
Ok((case, rust_params, rust_results))
})?;
let Declarations {
types,
type_instantiation_args,
params,
results,
import_and_export,
encoding1,
encoding2,
} = case.declarations();
let test = quote!(#index => component_types::static_api_test::<(#rust_params), (#rust_results)>(
input,
{
static DECLS: Declarations = Declarations {
types: Cow::Borrowed(#types),
type_instantiation_args: Cow::Borrowed(#type_instantiation_args),
params: Cow::Borrowed(#params),
results: Cow::Borrowed(#results),
import_and_export: Cow::Borrowed(#import_and_export),
encoding1: #encoding1,
encoding2: #encoding2,
};
&DECLS
}
),);
tests.extend(test);
}
let module = quote! {
#[allow(unused_imports)]
fn static_component_api_target(input: &mut libfuzzer_sys::arbitrary::Unstructured) -> libfuzzer_sys::arbitrary::Result<()> {
use anyhow::Result;
use component_fuzz_util::Declarations;
use component_test_util::{self, Float32, Float64};
use libfuzzer_sys::arbitrary::{self, Arbitrary};
use std::borrow::Cow;
use std::sync::{Arc, Once};
use wasmtime::component::{ComponentType, Lift, Lower};
use wasmtime_fuzzing::generators::component_types;
const SEED: u64 = #seed;
static ONCE: Once = Once::new();
ONCE.call_once(|| {
eprintln!(
"Seed {SEED} was used to generate static component API fuzz tests.\n\
Set WASMTIME_FUZZ_SEED={SEED} in your environment at build time to reproduce."
);
});
#declarations
match input.int_in_range(0..=(#TEST_CASE_COUNT-1))? {
#tests
_ => unreachable!()
}
}
};
write!(out, "{module}")?;
Ok(())
}
fn gen<T>(
rng: &mut StdRng,
mut f: impl FnMut(&mut Unstructured<'_>) -> arbitrary::Result<T>,
) -> Result<T> {
let mut bytes = Vec::new();
loop {
let count = rng.gen_range(1000..2000);
bytes.extend(iter::repeat_with(|| rng.gen::<u8>()).take(count));
match f(&mut Unstructured::new(&bytes)) {
Ok(ret) => break Ok(ret),
Err(arbitrary::Error::NotEnoughData) => (),
Err(error) => break Err(Error::from(error)),
}
}
}
}
|
