rewrite remap-path-prefix-dwarf to rmake

src/tools/run-make-support/src/external_deps/llvm.rs

@@ -36,6 +36,12 @@ pub fn llvm_ar() -> LlvmAr {
     LlvmAr::new()
 }
 
+/// Construct a new `llvm-dwarfdump` invocation. This assumes that `llvm-dwarfdump` is available
+/// at `$LLVM_BIN_DIR/llvm-dwarfdump`.
+pub fn llvm_dwarfdump() -> LlvmDwarfdump {
+    LlvmDwarfdump::new()
+}
+
 /// A `llvm-readobj` invocation builder.
 #[derive(Debug)]
 #[must_use]
@@ -71,11 +77,19 @@ pub struct LlvmAr {
     cmd: Command,
 }
 
+/// A `llvm-dwarfdump` invocation builder.
+#[derive(Debug)]
+#[must_use]
+pub struct LlvmDwarfdump {
+    cmd: Command,
+}
+
 crate::macros::impl_common_helpers!(LlvmReadobj);
 crate::macros::impl_common_helpers!(LlvmProfdata);
 crate::macros::impl_common_helpers!(LlvmFilecheck);
 crate::macros::impl_common_helpers!(LlvmObjdump);
 crate::macros::impl_common_helpers!(LlvmAr);
+crate::macros::impl_common_helpers!(LlvmDwarfdump);
 
 /// Generate the path to the bin directory of LLVM.
 #[must_use]
@@ -244,3 +258,19 @@ impl LlvmAr {
         self
     }
 }
+
+impl LlvmDwarfdump {
+    /// Construct a new `llvm-dwarfdump` invocation. This assumes that `llvm-dwarfdump` is available
+    /// at `$LLVM_BIN_DIR/llvm-dwarfdump`.
+    pub fn new() -> Self {
+        let llvm_dwarfdump = llvm_bin_dir().join("llvm-dwarfdump");
+        let cmd = Command::new(llvm_dwarfdump);
+        Self { cmd }
+    }
+
+    /// Provide an input file.
+    pub fn input<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        self.cmd.arg(path.as_ref());
+        self
+    }
+}

src/tools/run-make-support/src/lib.rs

@@ -48,8 +48,8 @@ pub use cc::{cc, cxx, extra_c_flags, extra_cxx_flags, Cc};
 pub use clang::{clang, Clang};
 pub use htmldocck::htmldocck;
 pub use llvm::{
-    llvm_ar, llvm_filecheck, llvm_objdump, llvm_profdata, llvm_readobj, LlvmAr, LlvmFilecheck,
-    LlvmObjdump, LlvmProfdata, LlvmReadobj,
+    llvm_ar, llvm_dwarfdump, llvm_filecheck, llvm_objdump, llvm_profdata, llvm_readobj, LlvmAr,
+    LlvmDwarfdump, LlvmFilecheck, LlvmObjdump, LlvmProfdata, LlvmReadobj,
 };
 pub use python::python_command;
 pub use rustc::{aux_build, bare_rustc, rustc, Rustc};

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -42,7 +42,6 @@ run-make/print-target-list/Makefile
 run-make/raw-dylib-alt-calling-convention/Makefile
 run-make/raw-dylib-c/Makefile
 run-make/redundant-libs/Makefile
-run-make/remap-path-prefix-dwarf/Makefile
 run-make/reproducible-build-2/Makefile
 run-make/reproducible-build/Makefile
 run-make/rlib-format-packed-bundled-libs-2/Makefile

tests/run-make/remap-path-prefix-dwarf/rmake.rs

@@ -0,0 +1,202 @@
+// This test makes sure that --remap-path-prefix has the expected effects on paths in debuginfo.
+// We explicitly switch to a directory that *is* a prefix of the directory our
+// source code is contained in.
+// It tests several cases, each of them has a detailed description attached to it.
+// See https://github.com/rust-lang/rust/pull/96867
+
+//@ ignore-windows
+// Reason: the remap path prefix is not printed in the dwarf dump.
+
+use run_make_support::{cwd, is_darwin, llvm_dwarfdump, rust_lib_name, rustc};
+
+fn main() {
+    // The compiler is called with an *ABSOLUTE PATH* as input, and that absolute path *is* within
+    // the working directory of the compiler. We are remapping the path that contains `src`.
+    check_dwarf(DwarfTest {
+        lib_name: "abs_input_inside_working_dir",
+        input_path: PathType::Absolute,
+        scope: None,
+        remap_path_prefix: PrefixType::Regular(format!("{}=REMAPPED", cwd().display())),
+        dwarf_test: DwarfDump::ContainsSrcPath,
+    });
+    check_dwarf(DwarfTest {
+        lib_name: "abs_input_inside_working_dir_scope",
+        input_path: PathType::Absolute,
+        scope: Some(ScopeType::Object),
+        remap_path_prefix: PrefixType::Regular(format!("{}=REMAPPED", cwd().display())),
+        dwarf_test: DwarfDump::ContainsSrcPath,
+    });
+    // The compiler is called with an *ABSOLUTE PATH* as input, and that absolute path is *not*
+    // within the working directory of the compiler. We are remapping both the path that contains
+    // `src` and the working directory to the same thing. This setup corresponds to a workaround
+    // that is needed when trying to remap everything to something that looks like a local
+    // path. Relative paths are interpreted as relative to the compiler's working directory (e.g.
+    // in debuginfo). If we also remap the working directory, the compiler strip it from other
+    // paths so that the final outcome is the desired one again.
+    check_dwarf(DwarfTest {
+        lib_name: "abs_input_outside_working_dir",
+        input_path: PathType::Absolute,
+        scope: None,
+        remap_path_prefix: PrefixType::Dual((
+            format!("{}=REMAPPED", cwd().display()),
+            "rmake_out=REMAPPED".to_owned(),
+        )),
+        dwarf_test: DwarfDump::ContainsSrcPath,
+    });
+    // The compiler is called with a *RELATIVE PATH* as input. We are remapping the working
+    // directory of the compiler, which naturally is an implicit prefix of our relative input path.
+    // Debuginfo will expand the relative path to an absolute path and we expect the working
+    // directory to be remapped in that expansion.
+    check_dwarf(DwarfTest {
+        lib_name: "rel_input_remap_working_dir",
+        input_path: PathType::Relative,
+        scope: None,
+        remap_path_prefix: PrefixType::Regular(format!("{}=REMAPPED", cwd().display())),
+        dwarf_test: DwarfDump::ContainsSrcPath,
+    });
+    check_dwarf(DwarfTest {
+        lib_name: "rel_input_remap_working_dir_scope",
+        input_path: PathType::Relative,
+        scope: Some(ScopeType::Object),
+        remap_path_prefix: PrefixType::Regular(format!("{}=REMAPPED", cwd().display())),
+        dwarf_test: DwarfDump::ContainsSrcPath,
+    });
+    check_dwarf(DwarfTest {
+        lib_name: "rel_input_remap_working_dir_scope",
+        input_path: PathType::Relative,
+        scope: Some(ScopeType::Diagnostics),
+        remap_path_prefix: PrefixType::Regular(format!("{}=REMAPPED", cwd().display())),
+        dwarf_test: DwarfDump::AvoidSrcPath,
+    });
+    // The compiler is called with a *RELATIVE PATH* as input. We are remapping a *SUB-DIRECTORY*
+    // of the compiler's working directory. This test makes sure that that directory is remapped
+    // even though it won't actually show up in this form in the compiler's SourceMap and instead
+    // is only constructed on demand during debuginfo generation.
+    check_dwarf(DwarfTest {
+        lib_name: "rel_input_remap_working_dir_child",
+        input_path: PathType::Relative,
+        scope: None,
+        remap_path_prefix: PrefixType::Regular(format!("{}=REMAPPED", cwd().join("src").display())),
+        dwarf_test: DwarfDump::ChildTest,
+    });
+    // The compiler is called with a *RELATIVE PATH* as input. We are remapping a
+    // *PARENT DIRECTORY* of the compiler's working directory.
+    check_dwarf(DwarfTest {
+        lib_name: "rel_input_remap_working_dir_parent",
+        input_path: PathType::Relative,
+        scope: None,
+        remap_path_prefix: PrefixType::Regular(format!(
+            "{}=REMAPPED",
+            cwd().parent().unwrap().display()
+        )),
+        dwarf_test: DwarfDump::ParentTest,
+    });
+}
+
+#[track_caller]
+fn check_dwarf(test: DwarfTest) {
+    let mut rustc = rustc();
+    match test.input_path {
+        PathType::Absolute => rustc.input(cwd().join("src/quux.rs")),
+        PathType::Relative => rustc.input("src/quux.rs"),
+    };
+    rustc.output(rust_lib_name(test.lib_name));
+    rustc.arg("-Cdebuginfo=2");
+    if let Some(scope) = test.scope {
+        match scope {
+            ScopeType::Object => rustc.arg("-Zremap-path-scope=object"),
+            ScopeType::Diagnostics => rustc.arg("-Zremap-path-scope=diagnostics"),
+        };
+        if is_darwin() {
+            rustc.arg("-Csplit-debuginfo=off");
+        }
+    }
+    match test.remap_path_prefix {
+        PrefixType::Regular(prefix) => {
+            // We explicitly switch to a directory that *is* a prefix of the directory our
+            // source code is contained in.
+            rustc.arg("--remap-path-prefix");
+            rustc.arg(prefix);
+        }
+        PrefixType::Dual((prefix1, prefix2)) => {
+            // We explicitly switch to a directory that is *not* a prefix of the directory our
+            // source code is contained in.
+            rustc.arg("--remap-path-prefix");
+            rustc.arg(prefix1);
+            rustc.arg("--remap-path-prefix");
+            rustc.arg(prefix2);
+        }
+    }
+    rustc.run();
+    match test.dwarf_test {
+        DwarfDump::ContainsSrcPath => {
+            llvm_dwarfdump()
+                .input(rust_lib_name(test.lib_name))
+                .run()
+                // We expect the path to the main source file to be remapped.
+                .assert_stdout_contains("REMAPPED/src/quux.rs")
+                // No weird duplication of remapped components (see #78479)
+                .assert_stdout_not_contains("REMAPPED/REMAPPED");
+        }
+        DwarfDump::AvoidSrcPath => {
+            llvm_dwarfdump()
+                .input(rust_lib_name(test.lib_name))
+                .run()
+                .assert_stdout_not_contains("REMAPPED/src/quux.rs")
+                .assert_stdout_not_contains("REMAPPED/REMAPPED");
+        }
+        DwarfDump::ChildTest => {
+            llvm_dwarfdump()
+                .input(rust_lib_name(test.lib_name))
+                .run()
+                // We expect `src/quux.rs` to have been remapped to `REMAPPED/quux.rs`.
+                .assert_stdout_contains("REMAPPED/quux.rs")
+                // We don't want to find the path that we just remapped anywhere in the DWARF
+                .assert_stdout_not_contains(cwd().join("src").to_str().unwrap())
+                // No weird duplication of remapped components (see #78479)
+                .assert_stdout_not_contains("REMAPPED/REMAPPED");
+        }
+        DwarfDump::ParentTest => {
+            llvm_dwarfdump()
+                .input(rust_lib_name(test.lib_name))
+                .run()
+                // We expect `src/quux.rs` to have been remapped to
+                // `REMAPPED/remap-path-prefix-dwarf/src/quux.rs`.
+                .assert_stdout_contains("REMAPPED/rmake_out/src/quux.rs")
+                // We don't want to find the path that we just remapped anywhere in the DWARF
+                .assert_stdout_not_contains(cwd().parent().unwrap().to_str().unwrap())
+                // No weird duplication of remapped components (see #78479)
+                .assert_stdout_not_contains("REMAPPED/REMAPPED");
+        }
+    };
+}
+
+struct DwarfTest {
+    lib_name: &'static str,
+    input_path: PathType,
+    scope: Option<ScopeType>,
+    remap_path_prefix: PrefixType,
+    dwarf_test: DwarfDump,
+}
+
+enum PathType {
+    Absolute,
+    Relative,
+}
+
+enum ScopeType {
+    Object,
+    Diagnostics,
+}
+
+enum DwarfDump {
+    ContainsSrcPath,
+    AvoidSrcPath,
+    ChildTest,
+    ParentTest,
+}
+
+enum PrefixType {
+    Regular(String),
+    Dual((String, String)),
+}