Auto merge of #114750 - Enselic:metadata-dep-info, r=compiler-errors

Make `.rmeta` file in `dep-info` have correct name (`lib` prefix)

Since `filename_for_metadata()` and
`OutputFilenames::path(OutputType::Metadata)` had different logic for the name of the metadata file, the `.d` file contained a file name different from the actual name used. Share the logic to fix the out-of-sync name.

Without this fix, the `.d` file contained

    dash-separated_something-extra.rmeta: dash-separated.rs

instead of

    libdash_separated_something-extra.rmeta: dash-separated.rs

which is the name of the file that is actually written by the compiler.

Worth noting: It took me several iterations to get all tests to pass, so I am relatively confident that this PR does not break anything.

Closes #68839

compiler/rustc_interface/src/util.rs

@@ -568,6 +568,13 @@ pub fn build_output_filenames(attrs: &[ast::Attribute], sess: &Session) -> Outpu
     ) {
         sess.emit_fatal(errors::MultipleOutputTypesToStdout);
     }
+
+    let crate_name = sess
+        .opts
+        .crate_name
+        .clone()
+        .or_else(|| rustc_attr::find_crate_name(attrs).map(|n| n.to_string()));
+
     match sess.io.output_file {
         None => {
             // "-" as input file will cause the parser to read from stdin so we
@@ -576,15 +583,11 @@ pub fn build_output_filenames(attrs: &[ast::Attribute], sess: &Session) -> Outpu
             let dirpath = sess.io.output_dir.clone().unwrap_or_default();
 
             // If a crate name is present, we use it as the link name
-            let stem = sess
-                .opts
-                .crate_name
-                .clone()
-                .or_else(|| rustc_attr::find_crate_name(attrs).map(|n| n.to_string()))
-                .unwrap_or_else(|| sess.io.input.filestem().to_owned());
+            let stem = crate_name.clone().unwrap_or_else(|| sess.io.input.filestem().to_owned());
 
             OutputFilenames::new(
                 dirpath,
+                crate_name.unwrap_or_else(|| stem.replace('-', "_")),
                 stem,
                 None,
                 sess.io.temps_dir.clone(),
@@ -609,9 +612,12 @@ pub fn build_output_filenames(attrs: &[ast::Attribute], sess: &Session) -> Outpu
                 sess.emit_warning(errors::IgnoringOutDir);
             }
 
+            let out_filestem =
+                out_file.filestem().unwrap_or_default().to_str().unwrap().to_string();
             OutputFilenames::new(
                 out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(),
-                out_file.filestem().unwrap_or_default().to_str().unwrap().to_string(),
+                crate_name.unwrap_or_else(|| out_filestem.replace('-', "_")),
+                out_filestem,
                 ofile,
                 sess.io.temps_dir.clone(),
                 sess.opts.cg.extra_filename.clone(),

compiler/rustc_metadata/src/fs.rs

@@ -5,7 +5,6 @@ use crate::errors::{
 use crate::{encode_metadata, EncodedMetadata};
 
 use rustc_data_structures::temp_dir::MaybeTempDir;
-use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{OutFileName, OutputType};
 use rustc_session::output::filename_for_metadata;
@@ -40,8 +39,7 @@ pub fn emit_wrapper_file(
 }
 
 pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> (EncodedMetadata, bool) {
-    let crate_name = tcx.crate_name(LOCAL_CRATE);
-    let out_filename = filename_for_metadata(tcx.sess, crate_name, tcx.output_filenames(()));
+    let out_filename = filename_for_metadata(tcx.sess, tcx.output_filenames(()));
     // To avoid races with another rustc process scanning the output directory,
     // we need to write the file somewhere else and atomically move it to its
     // final destination, with an `fs::rename` call. In order for the rename to

compiler/rustc_session/src/config.rs

@@ -898,6 +898,9 @@ impl OutFileName {
 #[derive(Clone, Hash, Debug, HashStable_Generic)]
 pub struct OutputFilenames {
     pub out_directory: PathBuf,
+    /// Crate name. Never contains '-'.
+    crate_stem: String,
+    /// Typically based on `.rs` input file name. Any '-' is preserved.
     filestem: String,
     pub single_output_file: Option<OutFileName>,
     pub temps_directory: Option<PathBuf>,
@@ -911,6 +914,7 @@ pub const DWARF_OBJECT_EXT: &str = "dwo";
 impl OutputFilenames {
     pub fn new(
         out_directory: PathBuf,
+        out_crate_name: String,
         out_filestem: String,
         single_output_file: Option<OutFileName>,
         temps_directory: Option<PathBuf>,
@@ -922,6 +926,7 @@ impl OutputFilenames {
             single_output_file,
             temps_directory,
             outputs,
+            crate_stem: format!("{out_crate_name}{extra}"),
             filestem: format!("{out_filestem}{extra}"),
         }
     }
@@ -938,7 +943,12 @@ impl OutputFilenames {
     /// should be placed on disk.
     pub fn output_path(&self, flavor: OutputType) -> PathBuf {
         let extension = flavor.extension();
-        self.with_directory_and_extension(&self.out_directory, extension)
+        match flavor {
+            OutputType::Metadata => {
+                self.out_directory.join(format!("lib{}.{}", self.crate_stem, extension))
+            }
+            _ => self.with_directory_and_extension(&self.out_directory, extension),
+        }
     }
 
     /// Gets the path where a compilation artifact of the given type for the

compiler/rustc_session/src/output.rs

@@ -119,26 +119,11 @@ pub fn validate_crate_name(sess: &Session, s: Symbol, sp: Option<Span>) {
     }
 }
 
-pub fn filename_for_metadata(
-    sess: &Session,
-    crate_name: Symbol,
-    outputs: &OutputFilenames,
-) -> OutFileName {
-    // If the command-line specified the path, use that directly.
-    if let Some(Some(out_filename)) = sess.opts.output_types.get(&OutputType::Metadata) {
-        return out_filename.clone();
-    }
-
-    let libname = format!("{}{}", crate_name, sess.opts.cg.extra_filename);
-
-    let out_filename = outputs.single_output_file.clone().unwrap_or_else(|| {
-        OutFileName::Real(outputs.out_directory.join(&format!("lib{libname}.rmeta")))
-    });
-
+pub fn filename_for_metadata(sess: &Session, outputs: &OutputFilenames) -> OutFileName {
+    let out_filename = outputs.path(OutputType::Metadata);
     if let OutFileName::Real(ref path) = out_filename {
         check_file_is_writeable(path, sess);
     }
-
     out_filename
 }
 

tests/run-make/metadata-dep-info/Makefile

@@ -0,0 +1,13 @@
+include ../tools.mk
+
+ifdef RUSTC_BLESS_TEST
+    RUSTC_TEST_OP = cp
+else
+    RUSTC_TEST_OP = $(DIFF)
+endif
+
+all:
+	$(RUSTC) --emit=metadata,dep-info --crate-type lib dash-separated.rs -C extra-filename=_something-extra
+	# Strip TMPDIR since it is a machine specific absolute path
+	sed "s%.*[/\\]%%" "$(TMPDIR)"/dash-separated_something-extra.d > "$(TMPDIR)"/dash-separated_something-extra.normalized.d
+	$(RUSTC_TEST_OP) "$(TMPDIR)"/dash-separated_something-extra.normalized.d dash-separated_something-extra.normalized.d

tests/run-make/metadata-dep-info/dash-separated.rs

@@ -0,0 +1,4 @@
+//! It is important that this file has at least one `-` in the file name since
+//! we want to test that it becomes a `_` when appropriate.
+
+pub struct Foo;

tests/run-make/metadata-dep-info/dash-separated_something-extra.normalized.d

@@ -0,0 +1,5 @@
+libdash_separated_something-extra.rmeta: dash-separated.rs
+
+dash-separated_something-extra.d: dash-separated.rs
+
+dash-separated.rs: