1 //! This pass is only used for UNIT TESTS related to incremental
2 //! compilation. It tests whether a particular `.o` file will be re-used
3 //! from a previous compilation or whether it must be regenerated.
5 //! The user adds annotations to the crate of the following form:
8 //! #![rustc_partition_reused(module="spike", cfg="rpass2")]
9 //! #![rustc_partition_codegened(module="spike-x", cfg="rpass2")]
12 //! The first indicates (in the cfg `rpass2`) that `spike.o` will be
13 //! reused, the second that `spike-x.o` will be recreated. If these
14 //! annotations are inaccurate, errors are reported.
16 //! The reason that we use `cfg=...` and not `#[cfg_attr]` is so that
17 //! the HIR doesn't change as a result of the annotations, which might
18 //! perturb the reuse results.
20 //! `#![rustc_expected_cgu_reuse(module="spike", cfg="rpass2", kind="post-lto")]
21 //! allows for doing a more fine-grained check to see if pre- or post-lto data
24 use rustc::mir::mono::CodegenUnitNameBuilder;
25 use rustc::ty::TyCtxt;
27 use rustc_hir::def_id::LOCAL_CRATE;
28 use rustc_session::cgu_reuse_tracker::*;
29 use rustc_span::symbol::{sym, Symbol};
30 use std::collections::BTreeSet;
32 pub fn assert_module_sources(tcx: TyCtxt<'_>) {
33 tcx.dep_graph.with_ignore(|| {
34 if tcx.sess.opts.incremental.is_none() {
38 let available_cgus = tcx
39 .collect_and_partition_mono_items(LOCAL_CRATE)
42 .map(|cgu| cgu.name())
43 .collect::<BTreeSet<Symbol>>();
45 let ams = AssertModuleSource { tcx, available_cgus };
47 for attr in tcx.hir().krate().attrs {
53 struct AssertModuleSource<'tcx> {
55 available_cgus: BTreeSet<Symbol>,
58 impl AssertModuleSource<'tcx> {
59 fn check_attr(&self, attr: &ast::Attribute) {
60 let (expected_reuse, comp_kind) = if attr.check_name(sym::rustc_partition_reused) {
61 (CguReuse::PreLto, ComparisonKind::AtLeast)
62 } else if attr.check_name(sym::rustc_partition_codegened) {
63 (CguReuse::No, ComparisonKind::Exact)
64 } else if attr.check_name(sym::rustc_expected_cgu_reuse) {
65 match &*self.field(attr, sym::kind).as_str() {
66 "no" => (CguReuse::No, ComparisonKind::Exact),
67 "pre-lto" => (CguReuse::PreLto, ComparisonKind::Exact),
68 "post-lto" => (CguReuse::PostLto, ComparisonKind::Exact),
69 "any" => (CguReuse::PreLto, ComparisonKind::AtLeast),
71 self.tcx.sess.span_fatal(
73 &format!("unknown cgu-reuse-kind `{}` specified", other),
81 if !self.tcx.sess.opts.debugging_opts.query_dep_graph {
82 self.tcx.sess.span_fatal(
84 "found CGU-reuse attribute but `-Zquery-dep-graph` was not specified",
88 if !self.check_config(attr) {
89 debug!("check_attr: config does not match, ignoring attr");
93 let user_path = self.field(attr, sym::module).to_string();
94 let crate_name = self.tcx.crate_name(LOCAL_CRATE).to_string();
96 if !user_path.starts_with(&crate_name) {
98 "Found malformed codegen unit name `{}`. \
99 Codegen units names must always start with the name of the \
100 crate (`{}` in this case).",
101 user_path, crate_name
103 self.tcx.sess.span_fatal(attr.span, &msg);
106 // Split of the "special suffix" if there is one.
107 let (user_path, cgu_special_suffix) = if let Some(index) = user_path.rfind('.') {
108 (&user_path[..index], Some(&user_path[index + 1..]))
110 (&user_path[..], None)
113 let mut cgu_path_components = user_path.split('-').collect::<Vec<_>>();
115 // Remove the crate name
116 assert_eq!(cgu_path_components.remove(0), crate_name);
118 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(self.tcx);
120 cgu_name_builder.build_cgu_name(LOCAL_CRATE, cgu_path_components, cgu_special_suffix);
122 debug!("mapping '{}' to cgu name '{}'", self.field(attr, sym::module), cgu_name);
124 if !self.available_cgus.contains(&cgu_name) {
125 self.tcx.sess.span_err(
128 "no module named `{}` (mangled: {}). \
129 Available modules: {}",
134 .map(|cgu| cgu.to_string())
141 self.tcx.sess.cgu_reuse_tracker.set_expectation(
150 fn field(&self, attr: &ast::Attribute, name: Symbol) -> ast::Name {
151 for item in attr.meta_item_list().unwrap_or_else(Vec::new) {
152 if item.check_name(name) {
153 if let Some(value) = item.value_str() {
156 self.tcx.sess.span_fatal(
158 &format!("associated value expected for `{}`", name),
164 self.tcx.sess.span_fatal(attr.span, &format!("no field `{}`", name));
167 /// Scan for a `cfg="foo"` attribute and check whether we have a
168 /// cfg flag called `foo`.
169 fn check_config(&self, attr: &ast::Attribute) -> bool {
170 let config = &self.tcx.sess.parse_sess.config;
171 let value = self.field(attr, sym::cfg);
172 debug!("check_config(config={:?}, value={:?})", config, value);
173 if config.iter().any(|&(name, _)| name == value) {
174 debug!("check_config: matched");
177 debug!("check_config: no match found");