Merging upstream version 1.72.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 136 insertions, 30 deletions

diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index 42d8d2280..6b3facd04 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -24,7 +24,8 @@ use rustc_parse::{parse_crate_from_file, parse_crate_from_source_str, validate_a
 use rustc_passes::{self, hir_stats, layout_test};
 use rustc_plugin_impl as plugin;
 use rustc_resolve::Resolver;
-use rustc_session::config::{CrateType, Input, OutputFilenames, OutputType};
+use rustc_session::code_stats::VTableSizeInfo;
+use rustc_session::config::{CrateType, Input, OutFileName, OutputFilenames, OutputType};
 use rustc_session::cstore::{MetadataLoader, Untracked};
 use rustc_session::output::filename_for_input;
 use rustc_session::search_paths::PathKind;
@@ -373,19 +374,23 @@ fn generated_output_paths(
 ) -> Vec<PathBuf> {
     let mut out_filenames = Vec::new();
     for output_type in sess.opts.output_types.keys() {
-        let file = outputs.path(*output_type);
+        let out_filename = outputs.path(*output_type);
+        let file = out_filename.as_path().to_path_buf();
         match *output_type {
             // If the filename has been overridden using `-o`, it will not be modified
             // by appending `.rlib`, `.exe`, etc., so we can skip this transformation.
             OutputType::Exe if !exact_name => {
                 for crate_type in sess.crate_types().iter() {
                     let p = filename_for_input(sess, *crate_type, crate_name, outputs);
-                    out_filenames.push(p);
+                    out_filenames.push(p.as_path().to_path_buf());
                 }
             }
             OutputType::DepInfo if sess.opts.unstable_opts.dep_info_omit_d_target => {
                 // Don't add the dep-info output when omitting it from dep-info targets
             }
+            OutputType::DepInfo if out_filename.is_stdout() => {
+                // Don't add the dep-info output when it goes to stdout
+            }
             _ => {
                 out_filenames.push(file);
             }
@@ -452,7 +457,8 @@ fn write_out_deps(tcx: TyCtxt<'_>, outputs: &OutputFilenames, out_filenames: &[P
     if !sess.opts.output_types.contains_key(&OutputType::DepInfo) {
         return;
     }
-    let deps_filename = outputs.path(OutputType::DepInfo);
+    let deps_output = outputs.path(OutputType::DepInfo);
+    let deps_filename = deps_output.as_path();
 
     let result: io::Result<()> = try {
         // Build a list of files used to compile the output and
@@ -515,33 +521,47 @@ fn write_out_deps(tcx: TyCtxt<'_>, outputs: &OutputFilenames, out_filenames: &[P
             }
         }
 
-        let mut file = BufWriter::new(fs::File::create(&deps_filename)?);
-        for path in out_filenames {
-            writeln!(file, "{}: {}\n", path.display(), files.join(" "))?;
-        }
+        let write_deps_to_file = |file: &mut dyn Write| -> io::Result<()> {
+            for path in out_filenames {
+                writeln!(file, "{}: {}\n", path.display(), files.join(" "))?;
+            }
 
-        // Emit a fake target for each input file to the compilation. This
-        // prevents `make` from spitting out an error if a file is later
-        // deleted. For more info see #28735
-        for path in files {
-            writeln!(file, "{path}:")?;
-        }
+            // Emit a fake target for each input file to the compilation. This
+            // prevents `make` from spitting out an error if a file is later
+            // deleted. For more info see #28735
+            for path in files {
+                writeln!(file, "{path}:")?;
+            }
 
-        // Emit special comments with information about accessed environment variables.
-        let env_depinfo = sess.parse_sess.env_depinfo.borrow();
-        if !env_depinfo.is_empty() {
-            let mut envs: Vec<_> = env_depinfo
-                .iter()
-                .map(|(k, v)| (escape_dep_env(*k), v.map(escape_dep_env)))
-                .collect();
-            envs.sort_unstable();
-            writeln!(file)?;
-            for (k, v) in envs {
-                write!(file, "# env-dep:{k}")?;
-                if let Some(v) = v {
-                    write!(file, "={v}")?;
-                }
+            // Emit special comments with information about accessed environment variables.
+            let env_depinfo = sess.parse_sess.env_depinfo.borrow();
+            if !env_depinfo.is_empty() {
+                let mut envs: Vec<_> = env_depinfo
+                    .iter()
+                    .map(|(k, v)| (escape_dep_env(*k), v.map(escape_dep_env)))
+                    .collect();
+                envs.sort_unstable();
                 writeln!(file)?;
+                for (k, v) in envs {
+                    write!(file, "# env-dep:{k}")?;
+                    if let Some(v) = v {
+                        write!(file, "={v}")?;
+                    }
+                    writeln!(file)?;
+                }
+            }
+
+            Ok(())
+        };
+
+        match deps_output {
+            OutFileName::Stdout => {
+                let mut file = BufWriter::new(io::stdout());
+                write_deps_to_file(&mut file)?;
+            }
+            OutFileName::Real(ref path) => {
+                let mut file = BufWriter::new(fs::File::create(path)?);
+                write_deps_to_file(&mut file)?;
             }
         }
     };
@@ -720,8 +740,8 @@ pub fn create_global_ctxt<'tcx>(
     })
 }
 
-/// Runs the resolution, type-checking, region checking and other
-/// miscellaneous analysis passes on the crate.
+/// Runs the type-checking, region checking and other miscellaneous analysis
+/// passes on the crate.
 fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> {
     rustc_passes::hir_id_validator::check_crate(tcx);
 
@@ -847,6 +867,92 @@ fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> {
         sess.time("check_lint_expectations", || tcx.check_expectations(None));
     });
 
+    if sess.opts.unstable_opts.print_vtable_sizes {
+        let traits = tcx.traits(LOCAL_CRATE);
+
+        for &tr in traits {
+            if !tcx.check_is_object_safe(tr) {
+                continue;
+            }
+
+            let name = ty::print::with_no_trimmed_paths!(tcx.def_path_str(tr));
+
+            let mut first_dsa = true;
+
+            // Number of vtable entries, if we didn't have upcasting
+            let mut entries_ignoring_upcasting = 0;
+            // Number of vtable entries needed solely for upcasting
+            let mut entries_for_upcasting = 0;
+
+            let trait_ref = ty::Binder::dummy(ty::TraitRef::identity(tcx, tr));
+
+            // A slightly edited version of the code in `rustc_trait_selection::traits::vtable::vtable_entries`,
+            // that works without self type and just counts number of entries.
+            //
+            // Note that this is technically wrong, for traits which have associated types in supertraits:
+            //
+            //   trait A: AsRef<Self::T> + AsRef<()> { type T; }
+            //
+            // Without self type we can't normalize `Self::T`, so we can't know if `AsRef<Self::T>` and
+            // `AsRef<()>` are the same trait, thus we assume that those are different, and potentially
+            // over-estimate how many vtable entries there are.
+            //
+            // Similarly this is wrong for traits that have methods with possibly-impossible bounds.
+            // For example:
+            //
+            //   trait B<T> { fn f(&self) where T: Copy; }
+            //
+            // Here `dyn B<u8>` will have 4 entries, while `dyn B<String>` will only have 3.
+            // However, since we don't know `T`, we can't know if `T: Copy` holds or not,
+            // thus we lean on the bigger side and say it has 4 entries.
+            traits::vtable::prepare_vtable_segments(tcx, trait_ref, |segment| {
+                match segment {
+                    traits::vtable::VtblSegment::MetadataDSA => {
+                        // If this is the first dsa, it would be included either way,
+                        // otherwise it's needed for upcasting
+                        if std::mem::take(&mut first_dsa) {
+                            entries_ignoring_upcasting += 3;
+                        } else {
+                            entries_for_upcasting += 3;
+                        }
+                    }
+
+                    traits::vtable::VtblSegment::TraitOwnEntries { trait_ref, emit_vptr } => {
+                        // Lookup the shape of vtable for the trait.
+                        let own_existential_entries =
+                            tcx.own_existential_vtable_entries(trait_ref.def_id());
+
+                        // The original code here ignores the method if its predicates are impossible.
+                        // We can't really do that as, for example, all not trivial bounds on generic
+                        // parameters are impossible (since we don't know the parameters...),
+                        // see the comment above.
+                        entries_ignoring_upcasting += own_existential_entries.len();
+
+                        if emit_vptr {
+                            entries_for_upcasting += 1;
+                        }
+                    }
+                }
+
+                std::ops::ControlFlow::Continue::<std::convert::Infallible>(())
+            });
+
+            sess.code_stats.record_vtable_size(
+                tr,
+                &name,
+                VTableSizeInfo {
+                    trait_name: name.clone(),
+                    entries: entries_ignoring_upcasting + entries_for_upcasting,
+                    entries_ignoring_upcasting,
+                    entries_for_upcasting,
+                    upcasting_cost_percent: entries_for_upcasting as f64
+                        / entries_ignoring_upcasting as f64
+                        * 100.,
+                },
+            )
+        }
+    }
+
     Ok(())
 }