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
25 use rustc_hir::def_id::LOCAL_CRATE;
26 use rustc_middle::mir::mono::CodegenUnitNameBuilder;
27 use rustc_middle::ty::TyCtxt;
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(())
42 .map(|cgu| cgu.name().to_string())
43 .collect::<BTreeSet<String>>();
45 let ams = AssertModuleSource { tcx, available_cgus };
47 for attr in tcx.hir().attrs(rustc_hir::CRATE_HIR_ID) {
53 struct AssertModuleSource<'tcx> {
55 available_cgus: BTreeSet<String>,
58 impl AssertModuleSource<'tcx> {
59 fn check_attr(&self, attr: &ast::Attribute) {
60 let (expected_reuse, comp_kind) =
61 if self.tcx.sess.check_name(attr, sym::rustc_partition_reused) {
62 (CguReuse::PreLto, ComparisonKind::AtLeast)
63 } else if self.tcx.sess.check_name(attr, sym::rustc_partition_codegened) {
64 (CguReuse::No, ComparisonKind::Exact)
65 } else if self.tcx.sess.check_name(attr, sym::rustc_expected_cgu_reuse) {
66 match self.field(attr, sym::kind) {
67 sym::no => (CguReuse::No, ComparisonKind::Exact),
68 sym::pre_dash_lto => (CguReuse::PreLto, ComparisonKind::Exact),
69 sym::post_dash_lto => (CguReuse::PostLto, ComparisonKind::Exact),
70 sym::any => (CguReuse::PreLto, ComparisonKind::AtLeast),
72 self.tcx.sess.span_fatal(
74 &format!("unknown cgu-reuse-kind `{}` specified", other),
82 if !self.tcx.sess.opts.debugging_opts.query_dep_graph {
83 self.tcx.sess.span_fatal(
85 "found CGU-reuse attribute but `-Zquery-dep-graph` was not specified",
89 if !self.check_config(attr) {
90 debug!("check_attr: config does not match, ignoring attr");
94 let user_path = self.field(attr, sym::module).to_string();
95 let crate_name = self.tcx.crate_name(LOCAL_CRATE).to_string();
97 if !user_path.starts_with(&crate_name) {
99 "Found malformed codegen unit name `{}`. \
100 Codegen units names must always start with the name of the \
101 crate (`{}` in this case).",
102 user_path, crate_name
104 self.tcx.sess.span_fatal(attr.span, &msg);
107 // Split of the "special suffix" if there is one.
108 let (user_path, cgu_special_suffix) = if let Some(index) = user_path.rfind('.') {
109 (&user_path[..index], Some(&user_path[index + 1..]))
111 (&user_path[..], None)
114 let mut iter = user_path.split('-');
116 // Remove the crate name
117 assert_eq!(iter.next().unwrap(), crate_name);
119 let cgu_path_components = iter.collect::<Vec<_>>();
121 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(self.tcx);
123 cgu_name_builder.build_cgu_name(LOCAL_CRATE, cgu_path_components, cgu_special_suffix);
125 debug!("mapping '{}' to cgu name '{}'", self.field(attr, sym::module), cgu_name);
127 if !self.available_cgus.contains(&*cgu_name.as_str()) {
128 self.tcx.sess.span_err(
131 "no module named `{}` (mangled: {}). Available modules: {}",
136 .map(|cgu| cgu.to_string())
143 self.tcx.sess.cgu_reuse_tracker.set_expectation(
152 fn field(&self, attr: &ast::Attribute, name: Symbol) -> Symbol {
153 for item in attr.meta_item_list().unwrap_or_else(Vec::new) {
154 if item.has_name(name) {
155 if let Some(value) = item.value_str() {
158 self.tcx.sess.span_fatal(
160 &format!("associated value expected for `{}`", name),
166 self.tcx.sess.span_fatal(attr.span, &format!("no field `{}`", name));
169 /// Scan for a `cfg="foo"` attribute and check whether we have a
170 /// cfg flag called `foo`.
171 fn check_config(&self, attr: &ast::Attribute) -> bool {
172 let config = &self.tcx.sess.parse_sess.config;
173 let value = self.field(attr, sym::cfg);
174 debug!("check_config(config={:?}, value={:?})", config, value);
175 if config.iter().any(|&(name, _)| name == value) {
176 debug!("check_config: matched");
179 debug!("check_config: no match found");