1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Code that generates a test runner to run all the tests in a crate
14 #![allow(unused_imports)]
16 use self::HasTestSignature::*;
22 use attr::{self, HasAttrs};
23 use syntax_pos::{self, DUMMY_SP, NO_EXPANSION, Span, FileMap, BytePos};
25 use codemap::{self, CodeMap, ExpnInfo, MacroAttribute, dummy_spanned};
28 use entry::{self, EntryPointType};
29 use ext::base::{ExtCtxt, Resolver};
30 use ext::build::AstBuilder;
31 use ext::expand::ExpansionConfig;
32 use ext::hygiene::{self, Mark, SyntaxContext};
34 use feature_gate::Features;
35 use util::move_map::MoveMap;
37 use parse::{token, ParseSess};
39 use ast::{self, Ident};
41 use symbol::{self, Symbol, keywords};
42 use util::small_vector::SmallVector;
54 should_panic: ShouldPanic,
59 span_diagnostic: &'a errors::Handler,
63 reexport_test_harness_main: Option<Symbol>,
66 features: &'a Features,
68 // top-level re-export submodule, filled out after folding is finished
69 toplevel_reexport: Option<Ident>,
72 // Traverse the crate, collecting all the test functions, eliding any
73 // existing main functions, and synthesizing a main test harness
74 pub fn modify_for_testing(sess: &ParseSess,
75 resolver: &mut Resolver,
78 span_diagnostic: &errors::Handler,
79 features: &Features) -> ast::Crate {
80 // Check for #[reexport_test_harness_main = "some_name"] which
81 // creates a `use __test::main as some_name;`. This needs to be
82 // unconditional, so that the attribute is still marked as used in
84 let reexport_test_harness_main =
85 attr::first_attr_value_str_by_name(&krate.attrs,
86 "reexport_test_harness_main");
89 generate_test_harness(sess, resolver, reexport_test_harness_main,
90 krate, span_diagnostic, features)
96 struct TestHarnessGenerator<'a> {
100 // submodule name, gensym'd identifier for re-exports
101 tested_submods: Vec<(Ident, Ident)>,
104 impl<'a> fold::Folder for TestHarnessGenerator<'a> {
105 fn fold_crate(&mut self, c: ast::Crate) -> ast::Crate {
106 let mut folded = fold::noop_fold_crate(c, self);
108 // Add a special __test module to the crate that will contain code
109 // generated for the test harness
110 let (mod_, reexport) = mk_test_module(&mut self.cx);
111 if let Some(re) = reexport {
112 folded.module.items.push(re)
114 folded.module.items.push(mod_);
118 fn fold_item(&mut self, i: P<ast::Item>) -> SmallVector<P<ast::Item>> {
120 if ident.name != keywords::Invalid.name() {
121 self.cx.path.push(ident);
123 debug!("current path: {}", path_name_i(&self.cx.path));
125 if is_test_fn(&self.cx, &i) || is_bench_fn(&self.cx, &i) {
127 ast::ItemKind::Fn(_, header, _, _) => {
128 if header.unsafety == ast::Unsafety::Unsafe {
129 let diag = self.cx.span_diagnostic;
132 "unsafe functions cannot be used for tests"
135 if header.asyncness.is_async() {
136 let diag = self.cx.span_diagnostic;
139 "async functions cannot be used for tests"
146 debug!("this is a test function");
149 path: self.cx.path.clone(),
150 bench: is_bench_fn(&self.cx, &i),
151 ignore: is_ignored(&i),
152 should_panic: should_panic(&i, &self.cx),
153 allow_fail: is_allowed_fail(&i),
155 self.cx.testfns.push(test);
156 self.tests.push(i.ident);
159 let mut item = i.into_inner();
160 // We don't want to recurse into anything other than mods, since
161 // mods or tests inside of functions will break things
162 if let ast::ItemKind::Mod(module) = item.node {
163 let tests = mem::replace(&mut self.tests, Vec::new());
164 let tested_submods = mem::replace(&mut self.tested_submods, Vec::new());
165 let mut mod_folded = fold::noop_fold_mod(module, self);
166 let tests = mem::replace(&mut self.tests, tests);
167 let tested_submods = mem::replace(&mut self.tested_submods, tested_submods);
169 if !tests.is_empty() || !tested_submods.is_empty() {
170 let (it, sym) = mk_reexport_mod(&mut self.cx, item.id, tests, tested_submods);
171 mod_folded.items.push(it);
173 if !self.cx.path.is_empty() {
174 self.tested_submods.push((self.cx.path[self.cx.path.len()-1], sym));
176 debug!("pushing nothing, sym: {:?}", sym);
177 self.cx.toplevel_reexport = Some(sym);
180 item.node = ast::ItemKind::Mod(mod_folded);
182 if ident.name != keywords::Invalid.name() {
185 SmallVector::one(P(item))
188 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac { mac }
191 struct EntryPointCleaner {
192 // Current depth in the ast
196 impl fold::Folder for EntryPointCleaner {
197 fn fold_item(&mut self, i: P<ast::Item>) -> SmallVector<P<ast::Item>> {
199 let folded = fold::noop_fold_item(i, self).expect_one("noop did something");
202 // Remove any #[main] or #[start] from the AST so it doesn't
203 // clash with the one we're going to add, but mark it as
204 // #[allow(dead_code)] to avoid printing warnings.
205 let folded = match entry::entry_point_type(&folded, self.depth) {
206 EntryPointType::MainNamed |
207 EntryPointType::MainAttr |
208 EntryPointType::Start =>
209 folded.map(|ast::Item {id, ident, attrs, node, vis, span, tokens}| {
210 let allow_ident = Ident::from_str("allow");
211 let dc_nested = attr::mk_nested_word_item(Ident::from_str("dead_code"));
212 let allow_dead_code_item = attr::mk_list_item(DUMMY_SP, allow_ident,
214 let allow_dead_code = attr::mk_attr_outer(DUMMY_SP,
216 allow_dead_code_item);
221 attrs: attrs.into_iter()
223 !attr.check_name("main") && !attr.check_name("start")
225 .chain(iter::once(allow_dead_code))
233 EntryPointType::None |
234 EntryPointType::OtherMain => folded,
237 SmallVector::one(folded)
240 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac { mac }
243 fn mk_reexport_mod(cx: &mut TestCtxt,
246 tested_submods: Vec<(Ident, Ident)>)
247 -> (P<ast::Item>, Ident) {
248 let super_ = Ident::from_str("super");
250 let items = tests.into_iter().map(|r| {
251 cx.ext_cx.item_use_simple(DUMMY_SP, dummy_spanned(ast::VisibilityKind::Public),
252 cx.ext_cx.path(DUMMY_SP, vec![super_, r]))
253 }).chain(tested_submods.into_iter().map(|(r, sym)| {
254 let path = cx.ext_cx.path(DUMMY_SP, vec![super_, r, sym]);
255 cx.ext_cx.item_use_simple_(DUMMY_SP, dummy_spanned(ast::VisibilityKind::Public),
259 let reexport_mod = ast::Mod {
264 let sym = Ident::with_empty_ctxt(Symbol::gensym("__test_reexports"));
265 let parent = if parent == ast::DUMMY_NODE_ID { ast::CRATE_NODE_ID } else { parent };
266 cx.ext_cx.current_expansion.mark = cx.ext_cx.resolver.get_module_scope(parent);
267 let it = cx.ext_cx.monotonic_expander().fold_item(P(ast::Item {
270 id: ast::DUMMY_NODE_ID,
271 node: ast::ItemKind::Mod(reexport_mod),
272 vis: dummy_spanned(ast::VisibilityKind::Public),
280 fn generate_test_harness(sess: &ParseSess,
281 resolver: &mut Resolver,
282 reexport_test_harness_main: Option<Symbol>,
284 sd: &errors::Handler,
285 features: &Features) -> ast::Crate {
286 // Remove the entry points
287 let mut cleaner = EntryPointCleaner { depth: 0 };
288 let krate = cleaner.fold_crate(krate);
290 let mark = Mark::fresh(Mark::root());
292 let mut econfig = ExpansionConfig::default("test".to_string());
293 econfig.features = Some(features);
297 ext_cx: ExtCtxt::new(sess, econfig, resolver),
300 reexport_test_harness_main,
301 // NB: doesn't consider the value of `--crate-name` passed on the command line.
302 is_libtest: attr::find_crate_name(&krate.attrs).map(|s| s == "test").unwrap_or(false),
303 toplevel_reexport: None,
304 ctxt: SyntaxContext::empty().apply_mark(mark),
308 mark.set_expn_info(ExpnInfo {
311 format: MacroAttribute(Symbol::intern("test")),
312 allow_internal_unstable: true,
313 allow_internal_unsafe: false,
314 edition: hygiene::default_edition(),
317 TestHarnessGenerator {
320 tested_submods: Vec::new(),
324 /// Craft a span that will be ignored by the stability lint's
325 /// call to codemap's `is_internal` check.
326 /// The expanded code calls some unstable functions in the test crate.
327 fn ignored_span(cx: &TestCtxt, sp: Span) -> Span {
328 sp.with_ctxt(cx.ctxt)
332 enum HasTestSignature {
334 No(BadTestSignature),
338 enum BadTestSignature {
342 ShouldPanicOnlyWithNoArgs,
345 fn is_test_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
346 let has_test_attr = attr::contains_name(&i.attrs, "test");
348 fn has_test_signature(_cx: &TestCtxt, i: &ast::Item) -> HasTestSignature {
349 let has_should_panic_attr = attr::contains_name(&i.attrs, "should_panic");
351 ast::ItemKind::Fn(ref decl, _, ref generics, _) => {
352 // If the termination trait is active, the compiler will check that the output
353 // type implements the `Termination` trait as `libtest` enforces that.
354 let has_output = match decl.output {
355 ast::FunctionRetTy::Default(..) => false,
356 ast::FunctionRetTy::Ty(ref t) if t.node == ast::TyKind::Tup(vec![]) => false,
360 if !decl.inputs.is_empty() {
361 return No(BadTestSignature::NoArgumentsAllowed);
364 match (has_output, has_should_panic_attr) {
365 (true, true) => No(BadTestSignature::ShouldPanicOnlyWithNoArgs),
366 (true, false) => if !generics.params.is_empty() {
367 No(BadTestSignature::WrongTypeSignature)
374 _ => No(BadTestSignature::NotEvenAFunction),
378 let has_test_signature = if has_test_attr {
379 let diag = cx.span_diagnostic;
380 match has_test_signature(cx, i) {
384 BadTestSignature::NotEvenAFunction =>
385 diag.span_err(i.span, "only functions may be used as tests"),
386 BadTestSignature::WrongTypeSignature =>
387 diag.span_err(i.span,
388 "functions used as tests must have signature fn() -> ()"),
389 BadTestSignature::NoArgumentsAllowed =>
390 diag.span_err(i.span, "functions used as tests can not have any arguments"),
391 BadTestSignature::ShouldPanicOnlyWithNoArgs =>
392 diag.span_err(i.span, "functions using `#[should_panic]` must return `()`"),
401 has_test_attr && has_test_signature
404 fn is_bench_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
405 let has_bench_attr = attr::contains_name(&i.attrs, "bench");
407 fn has_bench_signature(_cx: &TestCtxt, i: &ast::Item) -> bool {
409 ast::ItemKind::Fn(ref decl, _, _, _) => {
410 // NB: inadequate check, but we're running
411 // well before resolve, can't get too deep.
412 decl.inputs.len() == 1
418 let has_bench_signature = has_bench_signature(cx, i);
420 if has_bench_attr && !has_bench_signature {
421 let diag = cx.span_diagnostic;
423 diag.span_err(i.span, "functions used as benches must have signature \
424 `fn(&mut Bencher) -> impl Termination`");
427 has_bench_attr && has_bench_signature
430 fn is_ignored(i: &ast::Item) -> bool {
431 attr::contains_name(&i.attrs, "ignore")
434 fn is_allowed_fail(i: &ast::Item) -> bool {
435 attr::contains_name(&i.attrs, "allow_fail")
438 fn should_panic(i: &ast::Item, cx: &TestCtxt) -> ShouldPanic {
439 match attr::find_by_name(&i.attrs, "should_panic") {
441 let sd = cx.span_diagnostic;
442 if attr.is_value_str() {
445 "attribute must be of the form: \
446 `#[should_panic]` or \
447 `#[should_panic(expected = \"error message\")]`"
448 ).note("Errors in this attribute were erroneously allowed \
449 and will become a hard error in a future release.")
451 return ShouldPanic::Yes(None);
453 match attr.meta_item_list() {
454 // Handle #[should_panic]
455 None => ShouldPanic::Yes(None),
456 // Handle #[should_panic(expected = "foo")]
458 let msg = list.iter()
459 .find(|mi| mi.check_name("expected"))
460 .and_then(|mi| mi.meta_item())
461 .and_then(|mi| mi.value_str());
462 if list.len() != 1 || msg.is_none() {
465 "argument must be of the form: \
466 `expected = \"error message\"`"
467 ).note("Errors in this attribute were erroneously \
468 allowed and will become a hard error in a \
469 future release.").emit();
470 ShouldPanic::Yes(None)
472 ShouldPanic::Yes(msg)
477 None => ShouldPanic::No,
483 We're going to be building a module that looks more or less like:
486 extern crate test (name = "test", vers = "...");
488 test::test_main_static(&::os::args()[], tests, test::Options::new())
491 static tests : &'static [test::TestDescAndFn] = &[
492 ... the list of tests in the crate ...
498 fn mk_std(cx: &TestCtxt) -> P<ast::Item> {
499 let id_test = Ident::from_str("test");
500 let sp = ignored_span(cx, DUMMY_SP);
501 let (vi, vis, ident) = if cx.is_libtest {
502 (ast::ItemKind::Use(P(ast::UseTree {
504 prefix: path_node(vec![id_test]),
505 kind: ast::UseTreeKind::Simple(None, ast::DUMMY_NODE_ID, ast::DUMMY_NODE_ID),
507 ast::VisibilityKind::Public, keywords::Invalid.ident())
509 (ast::ItemKind::ExternCrate(None), ast::VisibilityKind::Inherited, id_test)
512 id: ast::DUMMY_NODE_ID,
516 vis: dummy_spanned(vis),
522 fn mk_main(cx: &mut TestCtxt) -> P<ast::Item> {
523 // Writing this out by hand with 'ignored_span':
526 // use std::slice::AsSlice;
527 // test::test_main_static(::std::os::args().as_slice(), TESTS, test::Options::new());
530 let sp = ignored_span(cx, DUMMY_SP);
531 let ecx = &cx.ext_cx;
533 // test::test_main_static
535 ecx.path(sp, vec![Ident::from_str("test"), Ident::from_str("test_main_static")]);
537 // test::test_main_static(...)
538 let test_main_path_expr = ecx.expr_path(test_main_path);
539 let tests_ident_expr = ecx.expr_ident(sp, Ident::from_str("TESTS"));
540 let call_test_main = ecx.expr_call(sp, test_main_path_expr,
541 vec![tests_ident_expr]);
542 let call_test_main = ecx.stmt_expr(call_test_main);
544 let main_meta = ecx.meta_word(sp, Symbol::intern("main"));
545 let main_attr = ecx.attribute(sp, main_meta);
546 // pub fn main() { ... }
547 let main_ret_ty = ecx.ty(sp, ast::TyKind::Tup(vec![]));
548 let main_body = ecx.block(sp, vec![call_test_main]);
549 let main = ast::ItemKind::Fn(ecx.fn_decl(vec![], ast::FunctionRetTy::Ty(main_ret_ty)),
550 ast::FnHeader::default(),
551 ast::Generics::default(),
554 ident: Ident::from_str("main"),
555 attrs: vec![main_attr],
556 id: ast::DUMMY_NODE_ID,
558 vis: dummy_spanned(ast::VisibilityKind::Public),
564 fn mk_test_module(cx: &mut TestCtxt) -> (P<ast::Item>, Option<P<ast::Item>>) {
565 // Link to test crate
566 let import = mk_std(cx);
568 // A constant vector of test descriptors.
569 let tests = mk_tests(cx);
571 // The synthesized main function which will call the console test runner
572 // with our list of tests
573 let mainfn = mk_main(cx);
575 let testmod = ast::Mod {
577 items: vec![import, mainfn, tests],
579 let item_ = ast::ItemKind::Mod(testmod);
580 let mod_ident = Ident::with_empty_ctxt(Symbol::gensym("__test"));
582 let mut expander = cx.ext_cx.monotonic_expander();
583 let item = expander.fold_item(P(ast::Item {
584 id: ast::DUMMY_NODE_ID,
588 vis: dummy_spanned(ast::VisibilityKind::Public),
592 let reexport = cx.reexport_test_harness_main.map(|s| {
593 // building `use __test::main as <ident>;`
594 let rename = Ident::with_empty_ctxt(s);
596 let use_path = ast::UseTree {
598 prefix: path_node(vec![mod_ident, Ident::from_str("main")]),
599 kind: ast::UseTreeKind::Simple(Some(rename), ast::DUMMY_NODE_ID, ast::DUMMY_NODE_ID),
602 expander.fold_item(P(ast::Item {
603 id: ast::DUMMY_NODE_ID,
604 ident: keywords::Invalid.ident(),
606 node: ast::ItemKind::Use(P(use_path)),
607 vis: dummy_spanned(ast::VisibilityKind::Inherited),
613 debug!("Synthetic test module:\n{}\n", pprust::item_to_string(&item));
618 fn nospan<T>(t: T) -> codemap::Spanned<T> {
619 codemap::Spanned { node: t, span: DUMMY_SP }
622 fn path_node(ids: Vec<Ident>) -> ast::Path {
625 segments: ids.into_iter().map(|id| ast::PathSegment::from_ident(id)).collect(),
629 fn path_name_i(idents: &[Ident]) -> String {
630 let mut path_name = "".to_string();
631 let mut idents_iter = idents.iter().peekable();
632 while let Some(ident) = idents_iter.next() {
633 path_name.push_str(&ident.as_str());
634 if let Some(_) = idents_iter.peek() {
635 path_name.push_str("::")
641 fn mk_tests(cx: &TestCtxt) -> P<ast::Item> {
642 // The vector of test_descs for this crate
643 let test_descs = mk_test_descs(cx);
645 // FIXME #15962: should be using quote_item, but that stringifies
646 // __test_reexports, causing it to be reinterned, losing the
647 // gensym information.
648 let sp = ignored_span(cx, DUMMY_SP);
649 let ecx = &cx.ext_cx;
650 let struct_type = ecx.ty_path(ecx.path(sp, vec![ecx.ident_of("self"),
651 ecx.ident_of("test"),
652 ecx.ident_of("TestDescAndFn")]));
653 let static_lt = ecx.lifetime(sp, keywords::StaticLifetime.ident());
654 // &'static [self::test::TestDescAndFn]
655 let static_type = ecx.ty_rptr(sp,
656 ecx.ty(sp, ast::TyKind::Slice(struct_type)),
658 ast::Mutability::Immutable);
659 // static TESTS: $static_type = &[...];
661 ecx.ident_of("TESTS"),
666 fn mk_test_descs(cx: &TestCtxt) -> P<ast::Expr> {
667 debug!("building test vector from {} tests", cx.testfns.len());
670 id: ast::DUMMY_NODE_ID,
671 node: ast::ExprKind::AddrOf(ast::Mutability::Immutable,
673 id: ast::DUMMY_NODE_ID,
674 node: ast::ExprKind::Array(cx.testfns.iter().map(|test| {
675 mk_test_desc_and_fn_rec(cx, test)
678 attrs: ast::ThinVec::new(),
681 attrs: ast::ThinVec::new(),
685 fn mk_test_desc_and_fn_rec(cx: &TestCtxt, test: &Test) -> P<ast::Expr> {
686 // FIXME #15962: should be using quote_expr, but that stringifies
687 // __test_reexports, causing it to be reinterned, losing the
688 // gensym information.
690 let span = ignored_span(cx, test.span);
691 let ecx = &cx.ext_cx;
692 let self_id = ecx.ident_of("self");
693 let test_id = ecx.ident_of("test");
695 // creates self::test::$name
696 let test_path = |name| {
697 ecx.path(span, vec![self_id, test_id, ecx.ident_of(name)])
699 // creates $name: $expr
700 let field = |name, expr| ecx.field_imm(span, ecx.ident_of(name), expr);
702 // path to the #[test] function: "foo::bar::baz"
703 let path_string = path_name_i(&test.path[..]);
705 debug!("encoding {}", path_string);
707 let name_expr = ecx.expr_str(span, Symbol::intern(&path_string));
709 // self::test::StaticTestName($name_expr)
710 let name_expr = ecx.expr_call(span,
711 ecx.expr_path(test_path("StaticTestName")),
714 let ignore_expr = ecx.expr_bool(span, test.ignore);
715 let should_panic_path = |name| {
716 ecx.path(span, vec![self_id, test_id, ecx.ident_of("ShouldPanic"), ecx.ident_of(name)])
718 let fail_expr = match test.should_panic {
719 ShouldPanic::No => ecx.expr_path(should_panic_path("No")),
720 ShouldPanic::Yes(msg) => {
723 let msg = ecx.expr_str(span, msg);
724 let path = should_panic_path("YesWithMessage");
725 ecx.expr_call(span, ecx.expr_path(path), vec![msg])
727 None => ecx.expr_path(should_panic_path("Yes")),
731 let allow_fail_expr = ecx.expr_bool(span, test.allow_fail);
733 // self::test::TestDesc { ... }
734 let desc_expr = ecx.expr_struct(
736 test_path("TestDesc"),
737 vec![field("name", name_expr),
738 field("ignore", ignore_expr),
739 field("should_panic", fail_expr),
740 field("allow_fail", allow_fail_expr)]);
742 let mut visible_path = vec![];
743 if cx.features.extern_absolute_paths {
744 visible_path.push(keywords::Crate.ident());
746 match cx.toplevel_reexport {
747 Some(id) => visible_path.push(id),
749 let diag = cx.span_diagnostic;
750 diag.bug("expected to find top-level re-export name, but found None");
753 visible_path.extend_from_slice(&test.path[..]);
755 // Rather than directly give the test function to the test
756 // harness, we create a wrapper like one of the following:
758 // || test::assert_test_result(real_function()) // for test
759 // |b| test::assert_test_result(real_function(b)) // for bench
761 // this will coerce into a fn pointer that is specialized to the
762 // actual return type of `real_function` (Typically `()`, but not always).
764 // construct `real_function()` (this will be inserted into the overall expr)
765 let real_function_expr = ecx.expr_path(ecx.path_global(span, visible_path));
766 // construct path `test::assert_test_result`
767 let assert_test_result = test_path("assert_test_result");
769 // construct `|b| {..}`
770 let b_ident = Ident::with_empty_ctxt(Symbol::gensym("b"));
771 let b_expr = ecx.expr_ident(span, b_ident);
775 // construct `assert_test_result(..)`
778 ecx.expr_path(assert_test_result),
780 // construct `real_function(b)`
790 // construct `|| {..}`
794 // construct `assert_test_result(..)`
797 ecx.expr_path(assert_test_result),
799 // construct `real_function()`
811 let variant_name = if test.bench { "StaticBenchFn" } else { "StaticTestFn" };
813 // self::test::$variant_name($fn_expr)
814 let testfn_expr = ecx.expr_call(span, ecx.expr_path(test_path(variant_name)), vec![fn_expr]);
816 // self::test::TestDescAndFn { ... }
817 ecx.expr_struct(span,
818 test_path("TestDescAndFn"),
819 vec![field("desc", desc_expr),
820 field("testfn", testfn_expr)])