rust/src/libsyntax_ext/test.rs
2019-10-16 10:59:53 +02:00

379 lines
13 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 crate::util::check_builtin_macro_attribute;
use syntax::ast;
use syntax::attr;
use syntax_expand::base::*;
use syntax::print::pprust;
use syntax::source_map::respan;
use syntax::symbol::{Symbol, sym};
use syntax_pos::Span;
use std::iter;
// #[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 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);
if !ecx.ecfg.should_test { return vec![]; }
let sp = ecx.with_def_site_ctxt(attr_sp);
let mut item = anno_item.expect_item();
item = item.map(|mut item| {
item.vis = respan(item.vis.span, ast::VisibilityKind::Public);
item.ident.span = item.ident.span.with_ctxt(sp.ctxt());
item.attrs.push(
ecx.attribute(ecx.meta_word(sp, sym::rustc_test_marker))
);
item
});
return vec![Annotatable::Item(item)]
}
pub 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);
expand_test_or_bench(cx, attr_sp, item, false)
}
pub 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);
expand_test_or_bench(cx, attr_sp, item, true)
}
pub fn expand_test_or_bench(
cx: &mut 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 =
if let Annotatable::Item(i) = item { i }
else {
cx.parse_sess.span_diagnostic.span_fatal(item.span(),
"`#[test]` attribute is only allowed on non associated functions").raise();
};
if let ast::ItemKind::Mac(_) = item.kind {
cx.parse_sess.span_diagnostic.span_warn(item.span,
"`#[test]` attribute should not be used on macros. Use `#[cfg(test)]` instead.");
return vec![Annotatable::Item(item)];
}
// has_*_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.
if (!is_bench && !has_test_signature(cx, &item)) ||
(is_bench && !has_bench_signature(cx, &item)) {
return vec![Annotatable::Item(item)];
}
let (sp, attr_sp) = (cx.with_def_site_ctxt(item.span), cx.with_def_site_ctxt(attr_sp));
let test_id = ast::Ident::new(sym::test, attr_sp);
// creates test::$name
let test_path = |name| {
cx.path(sp, vec![test_id, cx.ident_of(name, sp)])
};
// creates test::ShouldPanic::$name
let should_panic_path = |name| {
cx.path(sp, vec![test_id, cx.ident_of("ShouldPanic", sp), cx.ident_of(name, sp)])
};
// creates test::TestType::$name
let test_type_path = |name| {
cx.path(sp, vec![test_id, cx.ident_of("TestType", sp), cx.ident_of(name, sp)])
};
// creates $name: $expr
let field = |name, expr| cx.field_imm(sp, cx.ident_of(name, sp), expr);
let test_fn = if is_bench {
// A simple ident for a lambda
let b = cx.ident_of("b", attr_sp);
cx.expr_call(sp, cx.expr_path(test_path("StaticBenchFn")), vec![
// |b| self::test::assert_test_result(
cx.lambda1(sp,
cx.expr_call(sp, cx.expr_path(test_path("assert_test_result")), vec![
// super::$test_fn(b)
cx.expr_call(sp,
cx.expr_path(cx.path(sp, vec![item.ident])),
vec![cx.expr_ident(sp, b)])
]),
b
)
// )
])
} else {
cx.expr_call(sp, cx.expr_path(test_path("StaticTestFn")), vec![
// || {
cx.lambda0(sp,
// test::assert_test_result(
cx.expr_call(sp, cx.expr_path(test_path("assert_test_result")), vec![
// $test_fn()
cx.expr_call(sp, cx.expr_path(cx.path(sp, vec![item.ident])), vec![])
// )
])
// }
)
// )
])
};
let mut test_const = cx.item(sp, ast::Ident::new(item.ident.name, sp),
vec![
// #[cfg(test)]
cx.attribute(attr::mk_list_item(ast::Ident::new(sym::cfg, attr_sp), vec![
attr::mk_nested_word_item(ast::Ident::new(sym::test, attr_sp))
])),
// #[rustc_test_marker]
cx.attribute(cx.meta_word(attr_sp, sym::rustc_test_marker)),
],
// const $ident: test::TestDescAndFn =
ast::ItemKind::Const(cx.ty(sp, ast::TyKind::Path(None, test_path("TestDescAndFn"))),
// test::TestDescAndFn {
cx.expr_struct(sp, test_path("TestDescAndFn"), vec![
// desc: test::TestDesc {
field("desc", cx.expr_struct(sp, test_path("TestDesc"), vec![
// name: "path::to::test"
field("name", cx.expr_call(sp, cx.expr_path(test_path("StaticTestName")),
vec![
cx.expr_str(sp, Symbol::intern(&item_path(
// skip the name of the root module
&cx.current_expansion.module.mod_path[1..],
&item.ident
)))
])),
// ignore: true | false
field("ignore", cx.expr_bool(sp, should_ignore(&item))),
// allow_fail: true | false
field("allow_fail", cx.expr_bool(sp, should_fail(&item))),
// 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")),
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)
// }
])
// }
));
test_const = test_const.map(|mut tc| { tc.vis.node = ast::VisibilityKind::Public; tc});
// extern crate test
let test_extern = cx.item(sp,
test_id,
vec![],
ast::ItemKind::ExternCrate(None)
);
log::debug!("synthetic test item:\n{}\n", pprust::item_to_string(&test_const));
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 item_path(mod_path: &[ast::Ident], item_ident: &ast::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_fail(i: &ast::Item) -> bool {
attr::contains_name(&i.attrs, sym::allow_fail)
}
fn should_panic(cx: &ExtCtxt<'_>, i: &ast::Item) -> ShouldPanic {
match attr::find_by_name(&i.attrs, sym::should_panic) {
Some(attr) => {
let ref sd = cx.parse_sess.span_diagnostic;
match attr.meta_item_list() {
// Handle #[should_panic(expected = "foo")]
Some(list) => {
let msg = list.iter()
.find(|mi| mi.check_name(sym::expected))
.and_then(|mi| mi.meta_item())
.and_then(|mi| mi.value_str());
if list.len() != 1 || msg.is_none() {
sd.struct_span_warn(
attr.span,
"argument must be of the form: \
`expected = \"error message\"`"
).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 has_test_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
let has_should_panic_attr = attr::contains_name(&i.attrs, sym::should_panic);
let ref sd = cx.parse_sess.span_diagnostic;
if let ast::ItemKind::Fn(ref decl, ref header, ref generics, _) = i.kind {
if header.unsafety == ast::Unsafety::Unsafe {
sd.span_err(
i.span,
"unsafe functions cannot be used for tests"
);
return false
}
if header.asyncness.node.is_async() {
sd.span_err(
i.span,
"async functions cannot be used for tests"
);
return false
}
// 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 decl.output {
ast::FunctionRetTy::Default(..) => false,
ast::FunctionRetTy::Ty(ref t) if t.kind.is_unit() => false,
_ => true
};
if !decl.inputs.is_empty() {
sd.span_err(i.span, "functions used as tests can not have any arguments");
return false;
}
match (has_output, has_should_panic_attr) {
(true, true) => {
sd.span_err(i.span, "functions using `#[should_panic]` must return `()`");
false
},
(true, false) => if !generics.params.is_empty() {
sd.span_err(i.span,
"functions used as tests must have signature fn() -> ()");
false
} else {
true
},
(false, _) => true
}
} else {
sd.span_err(i.span, "only functions may be used as tests");
false
}
}
fn has_bench_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
let has_sig = if let ast::ItemKind::Fn(ref decl, _, _, _) = i.kind {
// N.B., inadequate check, but we're running
// well before resolve, can't get too deep.
decl.inputs.len() == 1
} else {
false
};
if !has_sig {
cx.parse_sess.span_diagnostic.span_err(i.span, "functions used as benches must have \
signature `fn(&mut Bencher) -> impl Termination`");
}
has_sig
}