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use rustc_ast as ast;
use rustc_ast::entry::EntryPointType;
use rustc_ast::mut_visit::{ExpectOne, *};
use rustc_ast::ptr::P;
use rustc_ast::{attr, ModKind};
use rustc_expand::base::{ExtCtxt, ResolverExpand};
use rustc_expand::expand::{AstFragment, ExpansionConfig};
use rustc_feature::Features;
use rustc_session::Session;
use rustc_span::hygiene::{AstPass, SyntaxContext, Transparency};
use rustc_span::symbol::{sym, Ident, Symbol};
use rustc_span::{Span, DUMMY_SP};
use rustc_target::spec::PanicStrategy;
use smallvec::{smallvec, SmallVec};
use thin_vec::thin_vec;
use std::{iter, mem};
struct Test {
span: Span,
ident: Ident,
}
struct TestCtxt<'a> {
ext_cx: ExtCtxt<'a>,
panic_strategy: PanicStrategy,
def_site: Span,
test_cases: Vec<Test>,
reexport_test_harness_main: Option<Symbol>,
test_runner: Option<ast::Path>,
}
pub fn inject(sess: &Session, resolver: &mut dyn ResolverExpand, krate: &mut ast::Crate) {
let span_diagnostic = sess.diagnostic();
let panic_strategy = sess.panic_strategy();
let platform_panic_strategy = sess.target.panic_strategy;
let reexport_test_harness_main =
sess.first_attr_value_str_by_name(&krate.attrs, sym::reexport_test_harness_main);
let test_runner = get_test_runner(sess, span_diagnostic, &krate);
if sess.opts.test {
let panic_strategy = match (panic_strategy, sess.opts.unstable_opts.panic_abort_tests) {
(PanicStrategy::Abort, true) => PanicStrategy::Abort,
(PanicStrategy::Abort, false) => {
if panic_strategy == platform_panic_strategy {
} else {
span_diagnostic.err(
"building tests with panic=abort is not supported \
without `-Zpanic_abort_tests`",
);
}
PanicStrategy::Unwind
}
(PanicStrategy::Unwind, _) => PanicStrategy::Unwind,
};
generate_test_harness(
sess,
resolver,
reexport_test_harness_main,
krate,
&sess.features_untracked(),
panic_strategy,
test_runner,
)
}
}
struct TestHarnessGenerator<'a> {
cx: TestCtxt<'a>,
tests: Vec<Test>,
}
impl TestHarnessGenerator<'_> {
fn add_test_cases(&mut self, node_id: ast::NodeId, span: Span, prev_tests: Vec<Test>) {
let mut tests = mem::replace(&mut self.tests, prev_tests);
if !tests.is_empty() {
let expn_id = self.cx.ext_cx.resolver.expansion_for_ast_pass(
span,
AstPass::TestHarness,
&[],
Some(node_id),
);
for test in &mut tests {
test.ident.span =
test.ident.span.apply_mark(expn_id.to_expn_id(), Transparency::Opaque);
}
self.cx.test_cases.extend(tests);
}
}
}
impl<'a> MutVisitor for TestHarnessGenerator<'a> {
fn visit_crate(&mut self, c: &mut ast::Crate) {
let prev_tests = mem::take(&mut self.tests);
noop_visit_crate(c, self);
self.add_test_cases(ast::CRATE_NODE_ID, c.spans.inner_span, prev_tests);
c.items.push(mk_main(&mut self.cx));
}
fn flat_map_item(&mut self, i: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
let mut item = i.into_inner();
if is_test_case(&self.cx.ext_cx.sess, &item) {
debug!("this is a test item");
let test = Test { span: item.span, ident: item.ident };
self.tests.push(test);
}
if let ast::ItemKind::Mod(_, ModKind::Loaded(.., ref spans)) = item.kind {
let ast::ModSpans { inner_span: span, inject_use_span: _ } = *spans;
let prev_tests = mem::take(&mut self.tests);
noop_visit_item_kind(&mut item.kind, self);
self.add_test_cases(item.id, span, prev_tests);
}
smallvec![P(item)]
}
}
fn entry_point_type(sess: &Session, item: &ast::Item, depth: usize) -> EntryPointType {
match item.kind {
ast::ItemKind::Fn(..) => {
if sess.contains_name(&item.attrs, sym::start) {
EntryPointType::Start
} else if sess.contains_name(&item.attrs, sym::rustc_main) {
EntryPointType::RustcMainAttr
} else if item.ident.name == sym::main {
if depth == 0 {
EntryPointType::MainNamed
} else {
EntryPointType::OtherMain
}
} else {
EntryPointType::None
}
}
_ => EntryPointType::None,
}
}
struct EntryPointCleaner<'a> {
sess: &'a Session,
depth: usize,
def_site: Span,
}
impl<'a> MutVisitor for EntryPointCleaner<'a> {
fn flat_map_item(&mut self, i: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
self.depth += 1;
let item = noop_flat_map_item(i, self).expect_one("noop did something");
self.depth -= 1;
let item = match entry_point_type(self.sess, &item, self.depth) {
EntryPointType::MainNamed | EntryPointType::RustcMainAttr | EntryPointType::Start => {
item.map(|ast::Item { id, ident, attrs, kind, vis, span, tokens }| {
let allow_ident = Ident::new(sym::allow, self.def_site);
let dc_nested =
attr::mk_nested_word_item(Ident::new(sym::dead_code, self.def_site));
let allow_dead_code_item = attr::mk_list_item(allow_ident, vec![dc_nested]);
let allow_dead_code = attr::mk_attr_outer(
&self.sess.parse_sess.attr_id_generator,
allow_dead_code_item,
);
let attrs = attrs
.into_iter()
.filter(|attr| {
!attr.has_name(sym::rustc_main) && !attr.has_name(sym::start)
})
.chain(iter::once(allow_dead_code))
.collect();
ast::Item { id, ident, attrs, kind, vis, span, tokens }
})
}
EntryPointType::None | EntryPointType::OtherMain => item,
};
smallvec![item]
}
}
fn generate_test_harness(
sess: &Session,
resolver: &mut dyn ResolverExpand,
reexport_test_harness_main: Option<Symbol>,
krate: &mut ast::Crate,
features: &Features,
panic_strategy: PanicStrategy,
test_runner: Option<ast::Path>,
) {
let mut econfig = ExpansionConfig::default("test".to_string());
econfig.features = Some(features);
let ext_cx = ExtCtxt::new(sess, econfig, resolver, None);
let expn_id = ext_cx.resolver.expansion_for_ast_pass(
DUMMY_SP,
AstPass::TestHarness,
&[sym::test, sym::rustc_attrs],
None,
);
let def_site = DUMMY_SP.with_def_site_ctxt(expn_id.to_expn_id());
let mut cleaner = EntryPointCleaner { sess, depth: 0, def_site };
cleaner.visit_crate(krate);
let cx = TestCtxt {
ext_cx,
panic_strategy,
def_site,
test_cases: Vec::new(),
reexport_test_harness_main,
test_runner,
};
TestHarnessGenerator { cx, tests: Vec::new() }.visit_crate(krate);
}
fn mk_main(cx: &mut TestCtxt<'_>) -> P<ast::Item> {
let sp = cx.def_site;
let ecx = &cx.ext_cx;
let test_id = Ident::new(sym::test, sp);
let runner_name = match cx.panic_strategy {
PanicStrategy::Unwind => "test_main_static",
PanicStrategy::Abort => "test_main_static_abort",
};
let mut test_runner = cx
.test_runner
.clone()
.unwrap_or_else(|| ecx.path(sp, vec![test_id, Ident::from_str_and_span(runner_name, sp)]));
test_runner.span = sp;
let test_main_path_expr = ecx.expr_path(test_runner);
let call_test_main = ecx.expr_call(sp, test_main_path_expr, vec![mk_tests_slice(cx, sp)]);
let call_test_main = ecx.stmt_expr(call_test_main);
let test_extern_stmt = ecx.stmt_item(
sp,
ecx.item(sp, test_id, ast::AttrVec::new(), ast::ItemKind::ExternCrate(None)),
);
let main_meta = ecx.meta_word(sp, sym::rustc_main);
let main_attr = ecx.attribute(main_meta);
let main_ret_ty = ecx.ty(sp, ast::TyKind::Tup(vec![]));
let main_body = if cx.test_runner.is_none() {
ecx.block(sp, vec![test_extern_stmt, call_test_main])
} else {
ecx.block(sp, vec![call_test_main])
};
let decl = ecx.fn_decl(vec![], ast::FnRetTy::Ty(main_ret_ty));
let sig = ast::FnSig { decl, header: ast::FnHeader::default(), span: sp };
let defaultness = ast::Defaultness::Final;
let main = ast::ItemKind::Fn(Box::new(ast::Fn {
defaultness,
sig,
generics: ast::Generics::default(),
body: Some(main_body),
}));
let main_id = match cx.reexport_test_harness_main {
Some(sym) => Ident::new(sym, sp.with_ctxt(SyntaxContext::root())),
None => Ident::new(sym::main, sp),
};
let main = P(ast::Item {
ident: main_id,
attrs: thin_vec![main_attr],
id: ast::DUMMY_NODE_ID,
kind: main,
vis: ast::Visibility { span: sp, kind: ast::VisibilityKind::Public, tokens: None },
span: sp,
tokens: None,
});
let main = AstFragment::Items(smallvec![main]);
cx.ext_cx.monotonic_expander().fully_expand_fragment(main).make_items().pop().unwrap()
}
fn mk_tests_slice(cx: &TestCtxt<'_>, sp: Span) -> P<ast::Expr> {
debug!("building test vector from {} tests", cx.test_cases.len());
let ecx = &cx.ext_cx;
ecx.expr_array_ref(
sp,
cx.test_cases
.iter()
.map(|test| {
ecx.expr_addr_of(test.span, ecx.expr_path(ecx.path(test.span, vec![test.ident])))
})
.collect(),
)
}
fn is_test_case(sess: &Session, i: &ast::Item) -> bool {
sess.contains_name(&i.attrs, sym::rustc_test_marker)
}
fn get_test_runner(
sess: &Session,
sd: &rustc_errors::Handler,
krate: &ast::Crate,
) -> Option<ast::Path> {
let test_attr = sess.find_by_name(&krate.attrs, sym::test_runner)?;
let meta_list = test_attr.meta_item_list()?;
let span = test_attr.span;
match &*meta_list {
[single] => match single.meta_item() {
Some(meta_item) if meta_item.is_word() => return Some(meta_item.path.clone()),
_ => {
sd.struct_span_err(span, "`test_runner` argument must be a path").emit();
}
},
_ => {
sd.struct_span_err(span, "`#![test_runner(..)]` accepts exactly 1 argument").emit();
}
}
None
}