rust/src/libsyntax_ext/test.rs
2018-09-04 22:33:23 -07:00

335 lines
12 KiB
Rust

// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
/// 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 syntax::ext::base::*;
use syntax::ext::build::AstBuilder;
use syntax::ext::hygiene::{self, Mark, SyntaxContext};
use syntax::attr;
use syntax::ast;
use syntax::print::pprust;
use syntax::symbol::Symbol;
use syntax_pos::{DUMMY_SP, Span};
use syntax::source_map::{ExpnInfo, MacroAttribute};
use std::iter;
pub fn expand_test(
cx: &mut ExtCtxt,
attr_sp: Span,
_meta_item: &ast::MetaItem,
item: Annotatable,
) -> Vec<Annotatable> {
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> {
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 fn items").raise();
};
if let ast::ItemKind::Mac(_) = item.node {
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) = {
let mark = Mark::fresh(Mark::root());
mark.set_expn_info(ExpnInfo {
call_site: DUMMY_SP,
def_site: None,
format: MacroAttribute(Symbol::intern("test")),
allow_internal_unstable: true,
allow_internal_unsafe: false,
local_inner_macros: false,
edition: hygiene::default_edition(),
});
(item.span.with_ctxt(SyntaxContext::empty().apply_mark(mark)),
attr_sp.with_ctxt(SyntaxContext::empty().apply_mark(mark)))
};
// Gensym "test" so we can extern crate without conflicting with any local names
let test_id = cx.ident_of("test").gensym();
// creates test::$name
let test_path = |name| {
cx.path(sp, vec![test_id, cx.ident_of(name)])
};
// creates test::$name
let should_panic_path = |name| {
cx.path(sp, vec![test_id, cx.ident_of("ShouldPanic"), cx.ident_of(name)])
};
// creates $name: $expr
let field = |name, expr| cx.field_imm(sp, cx.ident_of(name), expr);
let test_fn = if is_bench {
// A simple ident for a lambda
let b = cx.ident_of("b");
cx.expr_call(sp, cx.expr_path(test_path("StaticBenchFn")), vec![
// |b| self::test::assert_test_result(
cx.lambda1(sp,
cx.expr_call(sp, cx.expr_path(test_path("assert_test_result")), vec![
// super::$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, item.ident.gensym(),
vec![
// #[cfg(test)]
cx.attribute(attr_sp, cx.meta_list(attr_sp, Symbol::intern("cfg"), vec![
cx.meta_list_item_word(attr_sp, Symbol::intern("test"))
])),
// #[rustc_test_marker]
cx.attribute(attr_sp, cx.meta_word(attr_sp, Symbol::intern("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)]),
}),
// },
])),
// 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 as test_gensym
let test_extern = cx.item(sp,
test_id,
vec![],
ast::ItemKind::ExternCrate(Some(Symbol::intern("test")))
);
debug!("Synthetic test item:\n{}\n", pprust::item_to_string(&test_const));
vec![
// Access to libtest under a gensymed 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, "ignore")
}
fn should_fail(i: &ast::Item) -> bool {
attr::contains_name(&i.attrs, "allow_fail")
}
fn should_panic(cx: &ExtCtxt, i: &ast::Item) -> ShouldPanic {
match attr::find_by_name(&i.attrs, "should_panic") {
Some(attr) => {
let ref sd = cx.parse_sess.span_diagnostic;
if attr.is_value_str() {
sd.struct_span_warn(
attr.span(),
"attribute must be of the form: \
`#[should_panic]` or \
`#[should_panic(expected = \"error message\")]`"
).note("Errors in this attribute were erroneously allowed \
and will become a hard error in a future release.")
.emit();
return ShouldPanic::Yes(None);
}
match attr.meta_item_list() {
// Handle #[should_panic]
None => ShouldPanic::Yes(None),
// Handle #[should_panic(expected = "foo")]
Some(list) => {
let msg = list.iter()
.find(|mi| mi.check_name("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)
}
},
}
}
None => ShouldPanic::No,
}
}
fn has_test_signature(cx: &ExtCtxt, i: &ast::Item) -> bool {
let has_should_panic_attr = attr::contains_name(&i.attrs, "should_panic");
let ref sd = cx.parse_sess.span_diagnostic;
if let ast::ItemKind::Fn(ref decl, ref header, ref generics, _) = i.node {
if header.unsafety == ast::Unsafety::Unsafe {
sd.span_err(
i.span,
"unsafe functions cannot be used for tests"
);
return false
}
if header.asyncness.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.node.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.node {
// NB: 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
}