rust/src/libsyntax/test.rs

439 lines
15 KiB
Rust

// Code that generates a test runner to run all the tests in a crate
#![allow(dead_code)]
#![allow(unused_imports)]
use HasTestSignature::*;
use std::iter;
use std::slice;
use std::mem;
use std::vec;
use log::debug;
use smallvec::{smallvec, SmallVec};
use syntax_pos::{DUMMY_SP, NO_EXPANSION, Span, SourceFile, BytePos};
use crate::attr::{self, HasAttrs};
use crate::source_map::{self, SourceMap, ExpnInfo, MacroAttribute, dummy_spanned, respan};
use crate::config;
use crate::entry::{self, EntryPointType};
use crate::ext::base::{ExtCtxt, Resolver};
use crate::ext::build::AstBuilder;
use crate::ext::expand::ExpansionConfig;
use crate::ext::hygiene::{self, Mark, SyntaxContext};
use crate::mut_visit::{*, ExpectOne};
use crate::feature_gate::Features;
use crate::util::map_in_place::MapInPlace;
use crate::parse::{token, ParseSess};
use crate::print::pprust;
use crate::ast::{self, Ident};
use crate::ptr::P;
use crate::symbol::{self, Symbol, kw, sym};
use crate::ThinVec;
struct Test {
span: Span,
path: Vec<Ident>,
}
struct TestCtxt<'a> {
span_diagnostic: &'a errors::Handler,
path: Vec<Ident>,
ext_cx: ExtCtxt<'a>,
test_cases: Vec<Test>,
reexport_test_harness_main: Option<Symbol>,
is_libtest: bool,
ctxt: SyntaxContext,
features: &'a Features,
test_runner: Option<ast::Path>,
// top-level re-export submodule, filled out after folding is finished
toplevel_reexport: Option<Ident>,
}
// Traverse the crate, collecting all the test functions, eliding any
// existing main functions, and synthesizing a main test harness
pub fn modify_for_testing(sess: &ParseSess,
resolver: &mut dyn Resolver,
should_test: bool,
krate: &mut ast::Crate,
span_diagnostic: &errors::Handler,
features: &Features) {
// Check for #[reexport_test_harness_main = "some_name"] which
// creates a `use __test::main as some_name;`. This needs to be
// unconditional, so that the attribute is still marked as used in
// non-test builds.
let reexport_test_harness_main =
attr::first_attr_value_str_by_name(&krate.attrs, sym::reexport_test_harness_main);
// Do this here so that the test_runner crate attribute gets marked as used
// even in non-test builds
let test_runner = get_test_runner(span_diagnostic, &krate);
if should_test {
generate_test_harness(sess, resolver, reexport_test_harness_main,
krate, span_diagnostic, features, test_runner)
}
}
struct TestHarnessGenerator<'a> {
cx: TestCtxt<'a>,
tests: Vec<Ident>,
// submodule name, gensym'd identifier for re-exports
tested_submods: Vec<(Ident, Ident)>,
}
impl<'a> MutVisitor for TestHarnessGenerator<'a> {
fn visit_crate(&mut self, c: &mut ast::Crate) {
noop_visit_crate(c, self);
// Create a main function to run our tests
let test_main = {
let unresolved = mk_main(&mut self.cx);
self.cx.ext_cx.monotonic_expander().flat_map_item(unresolved).pop().unwrap()
};
c.module.items.push(test_main);
}
fn flat_map_item(&mut self, i: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
let ident = i.ident;
if ident.name != kw::Invalid {
self.cx.path.push(ident);
}
debug!("current path: {}", path_name_i(&self.cx.path));
let mut item = i.into_inner();
if is_test_case(&item) {
debug!("this is a test item");
let test = Test {
span: item.span,
path: self.cx.path.clone(),
};
self.cx.test_cases.push(test);
self.tests.push(item.ident);
}
// We don't want to recurse into anything other than mods, since
// mods or tests inside of functions will break things
if let ast::ItemKind::Mod(mut module) = item.node {
let tests = mem::replace(&mut self.tests, Vec::new());
let tested_submods = mem::replace(&mut self.tested_submods, Vec::new());
noop_visit_mod(&mut module, self);
let tests = mem::replace(&mut self.tests, tests);
let tested_submods = mem::replace(&mut self.tested_submods, tested_submods);
if !tests.is_empty() || !tested_submods.is_empty() {
let (it, sym) = mk_reexport_mod(&mut self.cx, item.id, tests, tested_submods);
module.items.push(it);
if !self.cx.path.is_empty() {
self.tested_submods.push((self.cx.path[self.cx.path.len()-1], sym));
} else {
debug!("pushing nothing, sym: {:?}", sym);
self.cx.toplevel_reexport = Some(sym);
}
}
item.node = ast::ItemKind::Mod(module);
}
if ident.name != kw::Invalid {
self.cx.path.pop();
}
smallvec![P(item)]
}
fn visit_mac(&mut self, _mac: &mut ast::Mac) {
// Do nothing.
}
}
/// A folder used to remove any entry points (like fn main) because the harness
/// generator will provide its own
struct EntryPointCleaner {
// Current depth in the ast
depth: usize,
}
impl MutVisitor for EntryPointCleaner {
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;
// Remove any #[main] or #[start] from the AST so it doesn't
// clash with the one we're going to add, but mark it as
// #[allow(dead_code)] to avoid printing warnings.
let item = match entry::entry_point_type(&item, self.depth) {
EntryPointType::MainNamed |
EntryPointType::MainAttr |
EntryPointType::Start =>
item.map(|ast::Item {id, ident, attrs, node, vis, span, tokens}| {
let allow_ident = Ident::with_empty_ctxt(sym::allow);
let dc_nested = attr::mk_nested_word_item(Ident::from_str("dead_code"));
let allow_dead_code_item = attr::mk_list_item(DUMMY_SP, allow_ident,
vec![dc_nested]);
let allow_dead_code = attr::mk_attr_outer(DUMMY_SP,
attr::mk_attr_id(),
allow_dead_code_item);
ast::Item {
id,
ident,
attrs: attrs.into_iter()
.filter(|attr| {
!attr.check_name(sym::main) && !attr.check_name(sym::start)
})
.chain(iter::once(allow_dead_code))
.collect(),
node,
vis,
span,
tokens,
}
}),
EntryPointType::None |
EntryPointType::OtherMain => item,
};
smallvec![item]
}
fn visit_mac(&mut self, _mac: &mut ast::Mac) {
// Do nothing.
}
}
/// Creates an item (specifically a module) that "pub use"s the tests passed in.
/// Each tested submodule will contain a similar reexport module that we will export
/// under the name of the original module. That is, `submod::__test_reexports` is
/// reexported like so `pub use submod::__test_reexports as submod`.
fn mk_reexport_mod(cx: &mut TestCtxt<'_>,
parent: ast::NodeId,
tests: Vec<Ident>,
tested_submods: Vec<(Ident, Ident)>)
-> (P<ast::Item>, Ident) {
let super_ = Ident::with_empty_ctxt(kw::Super);
let items = tests.into_iter().map(|r| {
cx.ext_cx.item_use_simple(DUMMY_SP, dummy_spanned(ast::VisibilityKind::Public),
cx.ext_cx.path(DUMMY_SP, vec![super_, r]))
}).chain(tested_submods.into_iter().map(|(r, sym)| {
let path = cx.ext_cx.path(DUMMY_SP, vec![super_, r, sym]);
cx.ext_cx.item_use_simple_(DUMMY_SP, dummy_spanned(ast::VisibilityKind::Public),
Some(r), path)
})).collect();
let reexport_mod = ast::Mod {
inline: true,
inner: DUMMY_SP,
items,
};
let name = Ident::from_str("__test_reexports").gensym();
let parent = if parent == ast::DUMMY_NODE_ID { ast::CRATE_NODE_ID } else { parent };
cx.ext_cx.current_expansion.mark = cx.ext_cx.resolver.get_module_scope(parent);
let it = cx.ext_cx.monotonic_expander().flat_map_item(P(ast::Item {
ident: name,
attrs: Vec::new(),
id: ast::DUMMY_NODE_ID,
node: ast::ItemKind::Mod(reexport_mod),
vis: dummy_spanned(ast::VisibilityKind::Public),
span: DUMMY_SP,
tokens: None,
})).pop().unwrap();
(it, name)
}
/// Crawl over the crate, inserting test reexports and the test main function
fn generate_test_harness(sess: &ParseSess,
resolver: &mut dyn Resolver,
reexport_test_harness_main: Option<Symbol>,
krate: &mut ast::Crate,
sd: &errors::Handler,
features: &Features,
test_runner: Option<ast::Path>) {
// Remove the entry points
let mut cleaner = EntryPointCleaner { depth: 0 };
cleaner.visit_crate(krate);
let mark = Mark::fresh(Mark::root());
let mut econfig = ExpansionConfig::default("test".to_string());
econfig.features = Some(features);
let cx = TestCtxt {
span_diagnostic: sd,
ext_cx: ExtCtxt::new(sess, econfig, resolver),
path: Vec::new(),
test_cases: Vec::new(),
reexport_test_harness_main,
// N.B., doesn't consider the value of `--crate-name` passed on the command line.
is_libtest: attr::find_crate_name(&krate.attrs)
.map(|s| s == sym::test).unwrap_or(false),
toplevel_reexport: None,
ctxt: SyntaxContext::empty().apply_mark(mark),
features,
test_runner
};
mark.set_expn_info(ExpnInfo::with_unstable(
MacroAttribute(sym::test_case), DUMMY_SP, sess.edition,
&[sym::main, sym::test, sym::rustc_attrs],
));
TestHarnessGenerator {
cx,
tests: Vec::new(),
tested_submods: Vec::new(),
}.visit_crate(krate);
}
/// Craft a span that will be ignored by the stability lint's
/// call to source_map's `is_internal` check.
/// The expanded code calls some unstable functions in the test crate.
fn ignored_span(cx: &TestCtxt<'_>, sp: Span) -> Span {
sp.with_ctxt(cx.ctxt)
}
enum HasTestSignature {
Yes,
No(BadTestSignature),
}
#[derive(PartialEq)]
enum BadTestSignature {
NotEvenAFunction,
WrongTypeSignature,
NoArgumentsAllowed,
ShouldPanicOnlyWithNoArgs,
}
/// Creates a function item for use as the main function of a test build.
/// This function will call the `test_runner` as specified by the crate attribute
fn mk_main(cx: &mut TestCtxt<'_>) -> P<ast::Item> {
// Writing this out by hand with 'ignored_span':
// pub fn main() {
// #![main]
// test::test_main_static(&[..tests]);
// }
let sp = ignored_span(cx, DUMMY_SP);
let ecx = &cx.ext_cx;
let test_id = Ident::with_empty_ctxt(sym::test);
// test::test_main_static(...)
let mut test_runner = cx.test_runner.clone().unwrap_or(
ecx.path(sp, vec![
test_id, ecx.ident_of("test_main_static")
]));
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)]);
let call_test_main = ecx.stmt_expr(call_test_main);
// #![main]
let main_meta = ecx.meta_word(sp, sym::main);
let main_attr = ecx.attribute(sp, main_meta);
// extern crate test as test_gensym
let test_extern_stmt = ecx.stmt_item(sp, ecx.item(sp,
test_id,
vec![],
ast::ItemKind::ExternCrate(None)
));
// pub fn main() { ... }
let main_ret_ty = ecx.ty(sp, ast::TyKind::Tup(vec![]));
// If no test runner is provided we need to import the test crate
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 main = ast::ItemKind::Fn(ecx.fn_decl(vec![], ast::FunctionRetTy::Ty(main_ret_ty)),
ast::FnHeader::default(),
ast::Generics::default(),
main_body);
// Honor the reexport_test_harness_main attribute
let main_id = match cx.reexport_test_harness_main {
Some(sym) => Ident::new(sym, sp),
None => Ident::from_str_and_span("main", sp).gensym(),
};
P(ast::Item {
ident: main_id,
attrs: vec![main_attr],
id: ast::DUMMY_NODE_ID,
node: main,
vis: dummy_spanned(ast::VisibilityKind::Public),
span: sp,
tokens: None,
})
}
fn path_name_i(idents: &[Ident]) -> String {
let mut path_name = "".to_string();
let mut idents_iter = idents.iter().peekable();
while let Some(ident) = idents_iter.next() {
path_name.push_str(&ident.as_str());
if idents_iter.peek().is_some() {
path_name.push_str("::")
}
}
path_name
}
/// Creates a slice containing every test like so:
/// &[path::to::test1, path::to::test2]
fn mk_tests_slice(cx: &TestCtxt<'_>) -> P<ast::Expr> {
debug!("building test vector from {} tests", cx.test_cases.len());
let ref ecx = cx.ext_cx;
ecx.expr_vec_slice(DUMMY_SP,
cx.test_cases.iter().map(|test| {
ecx.expr_addr_of(test.span,
ecx.expr_path(ecx.path(test.span, visible_path(cx, &test.path))))
}).collect())
}
/// Creates a path from the top-level __test module to the test via __test_reexports
fn visible_path(cx: &TestCtxt<'_>, path: &[Ident]) -> Vec<Ident>{
let mut visible_path = vec![];
match cx.toplevel_reexport {
Some(id) => visible_path.push(id),
None => {
cx.span_diagnostic.bug("expected to find top-level re-export name, but found None");
}
}
visible_path.extend_from_slice(path);
visible_path
}
fn is_test_case(i: &ast::Item) -> bool {
attr::contains_name(&i.attrs, sym::rustc_test_marker)
}
fn get_test_runner(sd: &errors::Handler, krate: &ast::Crate) -> Option<ast::Path> {
let test_attr = attr::find_by_name(&krate.attrs, sym::test_runner)?;
test_attr.meta_item_list().map(|meta_list| {
if meta_list.len() != 1 {
sd.span_fatal(test_attr.span,
"#![test_runner(..)] accepts exactly 1 argument").raise()
}
match meta_list[0].meta_item() {
Some(meta_item) if meta_item.is_word() => meta_item.path.clone(),
_ => sd.span_fatal(test_attr.span, "`test_runner` argument must be a path").raise()
}
})
}