rust/compiler/rustc_builtin_macros/src/test.rs

596 lines
22 KiB
Rust

//! The expansion from a test function to the appropriate test struct for libtest
//! Ideally, this code would be in libtest but for efficiency and error messages it lives here.
use std::assert_matches::assert_matches;
use std::iter;
use rustc_ast::ptr::P;
use rustc_ast::{self as ast, GenericParamKind, attr};
use rustc_ast_pretty::pprust;
use rustc_errors::{Applicability, Diag, Level};
use rustc_expand::base::*;
use rustc_span::symbol::{Ident, Symbol, sym};
use rustc_span::{ErrorGuaranteed, FileNameDisplayPreference, Span};
use thin_vec::{ThinVec, thin_vec};
use tracing::debug;
use crate::errors;
use crate::util::{check_builtin_macro_attribute, warn_on_duplicate_attribute};
/// #[test_case] is used by custom test authors to mark tests
/// When building for test, it needs to make the item public and gensym the name
/// Otherwise, we'll omit the item. This behavior means that any item annotated
/// with #[test_case] is never addressable.
///
/// We mark item with an inert attribute "rustc_test_marker" which the test generation
/// logic will pick up on.
pub(crate) fn expand_test_case(
ecx: &mut ExtCtxt<'_>,
attr_sp: Span,
meta_item: &ast::MetaItem,
anno_item: Annotatable,
) -> Vec<Annotatable> {
check_builtin_macro_attribute(ecx, meta_item, sym::test_case);
warn_on_duplicate_attribute(ecx, &anno_item, sym::test_case);
if !ecx.ecfg.should_test {
return vec![];
}
let sp = ecx.with_def_site_ctxt(attr_sp);
let (mut item, is_stmt) = match anno_item {
Annotatable::Item(item) => (item, false),
Annotatable::Stmt(stmt) if let ast::StmtKind::Item(_) = stmt.kind => {
if let ast::StmtKind::Item(i) = stmt.into_inner().kind {
(i, true)
} else {
unreachable!()
}
}
_ => {
ecx.dcx().emit_err(errors::TestCaseNonItem { span: anno_item.span() });
return vec![];
}
};
item = item.map(|mut item| {
let test_path_symbol = Symbol::intern(&item_path(
// skip the name of the root module
&ecx.current_expansion.module.mod_path[1..],
&item.ident,
));
item.vis = ast::Visibility {
span: item.vis.span,
kind: ast::VisibilityKind::Public,
tokens: None,
};
item.ident.span = item.ident.span.with_ctxt(sp.ctxt());
item.attrs.push(ecx.attr_name_value_str(sym::rustc_test_marker, test_path_symbol, sp));
item
});
let ret = if is_stmt {
Annotatable::Stmt(P(ecx.stmt_item(item.span, item)))
} else {
Annotatable::Item(item)
};
vec![ret]
}
pub(crate) fn expand_test(
cx: &mut ExtCtxt<'_>,
attr_sp: Span,
meta_item: &ast::MetaItem,
item: Annotatable,
) -> Vec<Annotatable> {
check_builtin_macro_attribute(cx, meta_item, sym::test);
warn_on_duplicate_attribute(cx, &item, sym::test);
expand_test_or_bench(cx, attr_sp, item, false)
}
pub(crate) fn expand_bench(
cx: &mut ExtCtxt<'_>,
attr_sp: Span,
meta_item: &ast::MetaItem,
item: Annotatable,
) -> Vec<Annotatable> {
check_builtin_macro_attribute(cx, meta_item, sym::bench);
warn_on_duplicate_attribute(cx, &item, sym::bench);
expand_test_or_bench(cx, attr_sp, item, true)
}
pub(crate) fn expand_test_or_bench(
cx: &ExtCtxt<'_>,
attr_sp: Span,
item: Annotatable,
is_bench: bool,
) -> Vec<Annotatable> {
// If we're not in test configuration, remove the annotated item
if !cx.ecfg.should_test {
return vec![];
}
let (item, is_stmt) = match item {
Annotatable::Item(i) => (i, false),
Annotatable::Stmt(stmt) if matches!(stmt.kind, ast::StmtKind::Item(_)) => {
// FIXME: Use an 'if let' guard once they are implemented
if let ast::StmtKind::Item(i) = stmt.into_inner().kind {
(i, true)
} else {
unreachable!()
}
}
other => {
not_testable_error(cx, attr_sp, None);
return vec![other];
}
};
let ast::ItemKind::Fn(fn_) = &item.kind else {
not_testable_error(cx, attr_sp, Some(&item));
return if is_stmt {
vec![Annotatable::Stmt(P(cx.stmt_item(item.span, item)))]
} else {
vec![Annotatable::Item(item)]
};
};
if let Some(attr) = attr::find_by_name(&item.attrs, sym::naked) {
cx.dcx().emit_err(errors::NakedFunctionTestingAttribute {
testing_span: attr_sp,
naked_span: attr.span,
});
return vec![Annotatable::Item(item)];
}
// check_*_signature will report any errors in the type so compilation
// will fail. We shouldn't try to expand in this case because the errors
// would be spurious.
let check_result = if is_bench {
check_bench_signature(cx, &item, fn_)
} else {
check_test_signature(cx, &item, fn_)
};
if check_result.is_err() {
return if is_stmt {
vec![Annotatable::Stmt(P(cx.stmt_item(item.span, item)))]
} else {
vec![Annotatable::Item(item)]
};
}
let sp = cx.with_def_site_ctxt(item.span);
let ret_ty_sp = cx.with_def_site_ctxt(fn_.sig.decl.output.span());
let attr_sp = cx.with_def_site_ctxt(attr_sp);
let test_id = Ident::new(sym::test, attr_sp);
// creates test::$name
let test_path = |name| cx.path(ret_ty_sp, vec![test_id, Ident::from_str_and_span(name, sp)]);
// creates test::ShouldPanic::$name
let should_panic_path = |name| {
cx.path(sp, vec![
test_id,
Ident::from_str_and_span("ShouldPanic", sp),
Ident::from_str_and_span(name, sp),
])
};
// creates test::TestType::$name
let test_type_path = |name| {
cx.path(sp, vec![
test_id,
Ident::from_str_and_span("TestType", sp),
Ident::from_str_and_span(name, sp),
])
};
// creates $name: $expr
let field = |name, expr| cx.field_imm(sp, Ident::from_str_and_span(name, sp), expr);
// Adds `#[coverage(off)]` to a closure, so it won't be instrumented in
// `-Cinstrument-coverage` builds.
// This requires `#[allow_internal_unstable(coverage_attribute)]` on the
// corresponding macro declaration in `core::macros`.
let coverage_off = |mut expr: P<ast::Expr>| {
assert_matches!(expr.kind, ast::ExprKind::Closure(_));
expr.attrs.push(cx.attr_nested_word(sym::coverage, sym::off, sp));
expr
};
let test_fn = if is_bench {
// A simple ident for a lambda
let b = Ident::from_str_and_span("b", attr_sp);
cx.expr_call(sp, cx.expr_path(test_path("StaticBenchFn")), thin_vec![
// #[coverage(off)]
// |b| self::test::assert_test_result(
coverage_off(cx.lambda1(
sp,
cx.expr_call(sp, cx.expr_path(test_path("assert_test_result")), thin_vec![
// super::$test_fn(b)
cx.expr_call(
ret_ty_sp,
cx.expr_path(cx.path(sp, vec![item.ident])),
thin_vec![cx.expr_ident(sp, b)],
),
],),
b,
)), // )
])
} else {
cx.expr_call(sp, cx.expr_path(test_path("StaticTestFn")), thin_vec![
// #[coverage(off)]
// || {
coverage_off(cx.lambda0(
sp,
// test::assert_test_result(
cx.expr_call(sp, cx.expr_path(test_path("assert_test_result")), thin_vec![
// $test_fn()
cx.expr_call(
ret_ty_sp,
cx.expr_path(cx.path(sp, vec![item.ident])),
ThinVec::new(),
), // )
],), // }
)), // )
])
};
let test_path_symbol = Symbol::intern(&item_path(
// skip the name of the root module
&cx.current_expansion.module.mod_path[1..],
&item.ident,
));
let location_info = get_location_info(cx, &item);
let mut test_const = cx.item(
sp,
Ident::new(item.ident.name, sp),
thin_vec![
// #[cfg(test)]
cx.attr_nested_word(sym::cfg, sym::test, attr_sp),
// #[rustc_test_marker = "test_case_sort_key"]
cx.attr_name_value_str(sym::rustc_test_marker, test_path_symbol, attr_sp),
// #[doc(hidden)]
cx.attr_nested_word(sym::doc, sym::hidden, attr_sp),
],
// const $ident: test::TestDescAndFn =
ast::ItemKind::Const(
ast::ConstItem {
defaultness: ast::Defaultness::Final,
generics: ast::Generics::default(),
ty: cx.ty(sp, ast::TyKind::Path(None, test_path("TestDescAndFn"))),
// test::TestDescAndFn {
expr: Some(
cx.expr_struct(sp, test_path("TestDescAndFn"), thin_vec![
// desc: test::TestDesc {
field(
"desc",
cx.expr_struct(sp, test_path("TestDesc"), thin_vec![
// name: "path::to::test"
field(
"name",
cx.expr_call(
sp,
cx.expr_path(test_path("StaticTestName")),
thin_vec![cx.expr_str(sp, test_path_symbol)],
),
),
// ignore: true | false
field("ignore", cx.expr_bool(sp, should_ignore(&item)),),
// ignore_message: Some("...") | None
field(
"ignore_message",
if let Some(msg) = should_ignore_message(&item) {
cx.expr_some(sp, cx.expr_str(sp, msg))
} else {
cx.expr_none(sp)
},
),
// source_file: <relative_path_of_source_file>
field("source_file", cx.expr_str(sp, location_info.0)),
// start_line: start line of the test fn identifier.
field("start_line", cx.expr_usize(sp, location_info.1)),
// start_col: start column of the test fn identifier.
field("start_col", cx.expr_usize(sp, location_info.2)),
// end_line: end line of the test fn identifier.
field("end_line", cx.expr_usize(sp, location_info.3)),
// end_col: end column of the test fn identifier.
field("end_col", cx.expr_usize(sp, location_info.4)),
// compile_fail: true | false
field("compile_fail", cx.expr_bool(sp, false)),
// no_run: true | false
field("no_run", cx.expr_bool(sp, false)),
// should_panic: ...
field("should_panic", match should_panic(cx, &item) {
// test::ShouldPanic::No
ShouldPanic::No => {
cx.expr_path(should_panic_path("No"))
}
// test::ShouldPanic::Yes
ShouldPanic::Yes(None) => {
cx.expr_path(should_panic_path("Yes"))
}
// test::ShouldPanic::YesWithMessage("...")
ShouldPanic::Yes(Some(sym)) => cx.expr_call(
sp,
cx.expr_path(should_panic_path("YesWithMessage")),
thin_vec![cx.expr_str(sp, sym)],
),
},),
// test_type: ...
field("test_type", match test_type(cx) {
// test::TestType::UnitTest
TestType::UnitTest => {
cx.expr_path(test_type_path("UnitTest"))
}
// test::TestType::IntegrationTest
TestType::IntegrationTest => {
cx.expr_path(test_type_path("IntegrationTest"))
}
// test::TestPath::Unknown
TestType::Unknown => {
cx.expr_path(test_type_path("Unknown"))
}
},),
// },
],),
),
// testfn: test::StaticTestFn(...) | test::StaticBenchFn(...)
field("testfn", test_fn), // }
]), // }
),
}
.into(),
),
);
test_const = test_const.map(|mut tc| {
tc.vis.kind = ast::VisibilityKind::Public;
tc
});
// extern crate test
let test_extern = cx.item(sp, test_id, ast::AttrVec::new(), ast::ItemKind::ExternCrate(None));
debug!("synthetic test item:\n{}\n", pprust::item_to_string(&test_const));
if is_stmt {
vec![
// Access to libtest under a hygienic name
Annotatable::Stmt(P(cx.stmt_item(sp, test_extern))),
// The generated test case
Annotatable::Stmt(P(cx.stmt_item(sp, test_const))),
// The original item
Annotatable::Stmt(P(cx.stmt_item(sp, item))),
]
} else {
vec![
// Access to libtest under a hygienic name
Annotatable::Item(test_extern),
// The generated test case
Annotatable::Item(test_const),
// The original item
Annotatable::Item(item),
]
}
}
fn not_testable_error(cx: &ExtCtxt<'_>, attr_sp: Span, item: Option<&ast::Item>) {
let dcx = cx.dcx();
let msg = "the `#[test]` attribute may only be used on a non-associated function";
let level = match item.map(|i| &i.kind) {
// These were a warning before #92959 and need to continue being that to avoid breaking
// stable user code (#94508).
Some(ast::ItemKind::MacCall(_)) => Level::Warning,
_ => Level::Error,
};
let mut err = Diag::<()>::new(dcx, level, msg);
err.span(attr_sp);
if let Some(item) = item {
err.span_label(
item.span,
format!(
"expected a non-associated function, found {} {}",
item.kind.article(),
item.kind.descr()
),
);
}
err.with_span_label(attr_sp, "the `#[test]` macro causes a function to be run as a test and has no effect on non-functions")
.with_span_suggestion(attr_sp,
"replace with conditional compilation to make the item only exist when tests are being run",
"#[cfg(test)]",
Applicability::MaybeIncorrect)
.emit();
}
fn get_location_info(cx: &ExtCtxt<'_>, item: &ast::Item) -> (Symbol, usize, usize, usize, usize) {
let span = item.ident.span;
let (source_file, lo_line, lo_col, hi_line, hi_col) =
cx.sess.source_map().span_to_location_info(span);
let file_name = match source_file {
Some(sf) => sf.name.display(FileNameDisplayPreference::Remapped).to_string(),
None => "no-location".to_string(),
};
(Symbol::intern(&file_name), lo_line, lo_col, hi_line, hi_col)
}
fn item_path(mod_path: &[Ident], item_ident: &Ident) -> String {
mod_path
.iter()
.chain(iter::once(item_ident))
.map(|x| x.to_string())
.collect::<Vec<String>>()
.join("::")
}
enum ShouldPanic {
No,
Yes(Option<Symbol>),
}
fn should_ignore(i: &ast::Item) -> bool {
attr::contains_name(&i.attrs, sym::ignore)
}
fn should_ignore_message(i: &ast::Item) -> Option<Symbol> {
match attr::find_by_name(&i.attrs, sym::ignore) {
Some(attr) => {
match attr.meta_item_list() {
// Handle #[ignore(bar = "foo")]
Some(_) => None,
// Handle #[ignore] and #[ignore = "message"]
None => attr.value_str(),
}
}
None => None,
}
}
fn should_panic(cx: &ExtCtxt<'_>, i: &ast::Item) -> ShouldPanic {
match attr::find_by_name(&i.attrs, sym::should_panic) {
Some(attr) => {
match attr.meta_item_list() {
// Handle #[should_panic(expected = "foo")]
Some(list) => {
let msg = list
.iter()
.find(|mi| mi.has_name(sym::expected))
.and_then(|mi| mi.meta_item())
.and_then(|mi| mi.value_str());
if list.len() != 1 || msg.is_none() {
cx.dcx()
.struct_span_warn(
attr.span,
"argument must be of the form: \
`expected = \"error message\"`",
)
.with_note(
"errors in this attribute were erroneously \
allowed and will become a hard error in a \
future release",
)
.emit();
ShouldPanic::Yes(None)
} else {
ShouldPanic::Yes(msg)
}
}
// Handle #[should_panic] and #[should_panic = "expected"]
None => ShouldPanic::Yes(attr.value_str()),
}
}
None => ShouldPanic::No,
}
}
enum TestType {
UnitTest,
IntegrationTest,
Unknown,
}
/// Attempts to determine the type of test.
/// Since doctests are created without macro expanding, only possible variants here
/// are `UnitTest`, `IntegrationTest` or `Unknown`.
fn test_type(cx: &ExtCtxt<'_>) -> TestType {
// Root path from context contains the topmost sources directory of the crate.
// I.e., for `project` with sources in `src` and tests in `tests` folders
// (no matter how many nested folders lie inside),
// there will be two different root paths: `/project/src` and `/project/tests`.
let crate_path = cx.root_path.as_path();
if crate_path.ends_with("src") {
// `/src` folder contains unit-tests.
TestType::UnitTest
} else if crate_path.ends_with("tests") {
// `/tests` folder contains integration tests.
TestType::IntegrationTest
} else {
// Crate layout doesn't match expected one, test type is unknown.
TestType::Unknown
}
}
fn check_test_signature(
cx: &ExtCtxt<'_>,
i: &ast::Item,
f: &ast::Fn,
) -> Result<(), ErrorGuaranteed> {
let has_should_panic_attr = attr::contains_name(&i.attrs, sym::should_panic);
let dcx = cx.dcx();
if let ast::Safety::Unsafe(span) = f.sig.header.safety {
return Err(dcx.emit_err(errors::TestBadFn { span: i.span, cause: span, kind: "unsafe" }));
}
if let Some(coroutine_kind) = f.sig.header.coroutine_kind {
match coroutine_kind {
ast::CoroutineKind::Async { span, .. } => {
return Err(dcx.emit_err(errors::TestBadFn {
span: i.span,
cause: span,
kind: "async",
}));
}
ast::CoroutineKind::Gen { span, .. } => {
return Err(dcx.emit_err(errors::TestBadFn {
span: i.span,
cause: span,
kind: "gen",
}));
}
ast::CoroutineKind::AsyncGen { span, .. } => {
return Err(dcx.emit_err(errors::TestBadFn {
span: i.span,
cause: span,
kind: "async gen",
}));
}
}
}
// If the termination trait is active, the compiler will check that the output
// type implements the `Termination` trait as `libtest` enforces that.
let has_output = match &f.sig.decl.output {
ast::FnRetTy::Default(..) => false,
ast::FnRetTy::Ty(t) if t.kind.is_unit() => false,
_ => true,
};
if !f.sig.decl.inputs.is_empty() {
return Err(dcx.span_err(i.span, "functions used as tests can not have any arguments"));
}
if has_should_panic_attr && has_output {
return Err(dcx.span_err(i.span, "functions using `#[should_panic]` must return `()`"));
}
if f.generics.params.iter().any(|param| !matches!(param.kind, GenericParamKind::Lifetime)) {
return Err(dcx.span_err(
i.span,
"functions used as tests can not have any non-lifetime generic parameters",
));
}
Ok(())
}
fn check_bench_signature(
cx: &ExtCtxt<'_>,
i: &ast::Item,
f: &ast::Fn,
) -> Result<(), ErrorGuaranteed> {
// N.B., inadequate check, but we're running
// well before resolve, can't get too deep.
if f.sig.decl.inputs.len() != 1 {
return Err(cx.dcx().emit_err(errors::BenchSig { span: i.span }));
}
Ok(())
}