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// Part of the Crubit project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//! A wrapper around `run_compiler` for testing only.
#![feature(rustc_private)]
extern crate rustc_driver;
extern crate rustc_error_codes;
extern crate rustc_errors;
extern crate rustc_feature;
extern crate rustc_interface;
extern crate rustc_lint_defs;
extern crate rustc_middle;
extern crate rustc_session;
extern crate rustc_span;
extern crate rustc_target;
use itertools::Itertools;
use rustc_middle::ty::TyCtxt;
use rustc_session::config::{CodegenOptions, CrateType, Input, Options, OutputType, OutputTypes};
use rustc_span::def_id::LocalDefId;
use std::path::PathBuf;
#[cfg(oss)]
const TOOLCHAIN_ROOT: &str = "rust_linux_x86_64__x86_64-unknown-linux-gnu__nightly_tools/rust_toolchain/lib/rustlib/x86_64-unknown-linux-gnu";
#[cfg(not(oss))]
const TOOLCHAIN_ROOT: &str = "google3/nowhere/llvm/rust/main_sysroot";
/// Returns the `rustc` sysroot that is suitable for the environment where
/// unit tests run.
///
/// The sysroot is used internally by `run_compiler_for_testing`, but it may
/// also be passed as `--sysroot=...` in `rustc_args` argument of
/// `run_compiler`
pub fn get_sysroot_for_testing() -> PathBuf {
let runfiles = runfiles::Runfiles::create().unwrap();
let loc = runfiles.rlocation(std::path::Path::new(TOOLCHAIN_ROOT));
assert!(loc.exists(), "Sysroot directory '{}' doesn't exist", loc.display());
assert!(loc.is_dir(), "Provided sysroot '{}' is not a directory", loc.display());
loc
}
/// `run_compiler_for_testing` is similar to `run_compiler`: it invokes the
/// `callback` after parsing and analysis are done, but instead of taking
/// `rustc_args` it:
///
/// * Invokes the Rust compiler on the given Rust `source`
/// * Hardcodes other compiler flags (e.g. picks Rust 2021 edition, and opts
/// into treating all warnings as errors).
pub fn run_compiler_for_testing<F, T>(source: impl Into<String>, callback: F) -> T
where
F: for<'tcx> FnOnce(TyCtxt<'tcx>) -> T + Send,
T: Send,
{
const TEST_FILENAME: &str = "crubit_unittests.rs";
// Setting `output_types` that will trigger code gen - otherwise some parts of
// the analysis will be missing (e.g. `tcx.exported_symbols()`).
// The choice of `Bitcode` is somewhat arbitrary (e.g. `Assembly`,
// `Mir`, etc. would also trigger code gen).
let output_types = OutputTypes::new(&[(OutputType::Bitcode, None /* PathBuf */)]);
let opts = Options {
crate_types: vec![CrateType::Rlib], // Test inputs simulate library crates.
maybe_sysroot: Some(get_sysroot_for_testing()),
output_types,
edition: rustc_span::edition::Edition::Edition2021,
unstable_features: rustc_feature::UnstableFeatures::Allow,
lint_opts: vec![
("warnings".to_string(), rustc_lint_defs::Level::Deny),
("stable_features".to_string(), rustc_lint_defs::Level::Allow),
],
cg: CodegenOptions {
// As pointed out in `panics_and_exceptions.md` the tool only supports `-C
// panic=abort` and therefore we explicitly opt into this config for tests.
panic: Some(rustc_target::spec::PanicStrategy::Abort),
..Default::default()
},
..Default::default()
};
let config = rustc_interface::interface::Config {
opts,
crate_cfg: Default::default(),
crate_check_cfg: Default::default(),
input: Input::Str {
name: rustc_span::FileName::Custom(TEST_FILENAME.to_string()),
input: source.into(),
},
output_file: None,
output_dir: None,
file_loader: None,
lint_caps: Default::default(),
parse_sess_created: None,
register_lints: None,
override_queries: None,
make_codegen_backend: None,
hash_untracked_state: None,
registry: rustc_errors::registry::Registry::new(rustc_error_codes::DIAGNOSTICS),
locale_resources: rustc_driver::DEFAULT_LOCALE_RESOURCES,
ice_file: None,
expanded_args: vec![],
using_internal_features: std::sync::Arc::new(false.into()),
};
rustc_interface::interface::run_compiler(config, |compiler| {
compiler.enter(|queries| {
use rustc_interface::interface::Result;
let try_func = || -> Result<T> {
let mut query_context = queries.global_ctxt()?;
query_context.enter(|tcx| {
// Explicitly force full `analysis` stage to detect compilation
// errors that the earlier stages might miss. This helps ensure that the
// test inputs are valid Rust (even if `callback` wouldn't
// have triggered full analysis).
tcx.analysis(())
})?;
// `analysis` might succeed even if there are some lint / warning errors.
// Detecting these requires explicitly checking `compile_status`.
compiler.sess.compile_status()?;
// Run the provided callback.
Ok(query_context.enter(callback))
};
try_func().expect("Test inputs shouldn't cause compilation errors")
})
})
}
/// Finds the definition id of a Rust item with the specified `name`.
/// Panics if no such item is found, or if there is more than one match.
pub fn find_def_id_by_name(tcx: TyCtxt, name: &str) -> LocalDefId {
let hir_items = || tcx.hir().items().map(|item_id| tcx.hir().item(item_id));
let items_with_matching_name =
hir_items().filter(|item| item.ident.name.as_str() == name).collect_vec();
match *items_with_matching_name.as_slice() {
[] => {
let found_names = hir_items()
.map(|item| item.ident.name.as_str())
.filter(|s| !s.is_empty())
.sorted()
.dedup()
.map(|name| format!("`{name}`"))
.join(",\n");
panic!("No items named `{name}`.\nInstead found:\n{found_names}");
}
[item] => item.owner_id.def_id,
_ => panic!("More than one item named `{name}`"),
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
#[should_panic(expected = "Test inputs shouldn't cause compilation errors")]
fn test_run_compiler_for_testing_panic_when_test_input_contains_syntax_errors() {
run_compiler_for_testing("syntax error here", |_tcx| panic!("This part shouldn't execute"))
}
#[test]
#[should_panic(expected = "Test inputs shouldn't cause compilation errors")]
fn test_run_compiler_for_testing_panic_when_test_input_triggers_analysis_errors() {
run_compiler_for_testing("#![feature(no_such_feature)]", |_tcx| {
panic!("This part shouldn't execute")
})
}
#[test]
#[should_panic(expected = "Test inputs shouldn't cause compilation errors")]
fn test_run_compiler_for_testing_panic_when_test_input_triggers_warnings() {
run_compiler_for_testing("pub fn foo(unused_parameter: i32) {}", |_tcx| {
panic!("This part shouldn't execute")
})
}
#[test]
fn test_run_compiler_for_testing_nightly_features_ok_in_test_input() {
// This test arbitrarily picks `yeet_expr` as an example of a feature that
// hasn't yet been stabilized.
let test_src = r#"
// This test is supposed to test that *nightly* features are ok
// in the test input. The `forbid` directive below helps to
// ensure that we'll realize in the future when the `yeet_expr`
// feature gets stabilized, making it not quite fitting for use
// in this test.
#![forbid(stable_features)]
#![feature(yeet_expr)]
"#;
run_compiler_for_testing(test_src, |_tcx| ())
}
#[test]
fn test_run_compiler_for_testing_stabilized_features_ok_in_test_input() {
// This test arbitrarily picks `const_ptr_offset_from` as an example of a
// feature that has been already stabilized.
run_compiler_for_testing("#![feature(const_ptr_offset_from)]", |_tcx| ())
}
#[test]
#[should_panic(expected = "No items named `missing_name`.\n\
Instead found:\n`bar`,\n`foo`,\n`m1`,\n`m2`,\n`std`")]
fn test_find_def_id_by_name_panic_when_no_item_with_matching_name() {
let test_src = r#"
pub extern "C" fn foo() {}
pub mod m1 {
pub fn bar() {}
}
pub mod m2 {
pub fn bar() {}
}
"#;
run_compiler_for_testing(test_src, |tcx| find_def_id_by_name(tcx, "missing_name"));
}
#[test]
#[should_panic(expected = "More than one item named `some_name`")]
fn test_find_def_id_by_name_panic_when_multiple_items_with_matching_name() {
let test_src = r#"
pub mod m1 {
pub fn some_name() {}
}
pub mod m2 {
pub fn some_name() {}
}
"#;
run_compiler_for_testing(test_src, |tcx| find_def_id_by_name(tcx, "some_name"));
}
}