Add a new Rust attribute to support embedding debugger visualizers

Cargo.lock

@@ -4183,6 +4183,7 @@ dependencies = [
  "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
+ "rustc_expand",
  "rustc_feature",
  "rustc_hir",
  "rustc_index",

compiler/rustc_builtin_macros/src/source_util.rs

@@ -3,17 +3,15 @@ use rustc_ast::ptr::P;
 use rustc_ast::token;
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast_pretty::pprust;
-use rustc_errors::PResult;
 use rustc_expand::base::{self, *};
 use rustc_expand::module::DirOwnership;
 use rustc_parse::parser::{ForceCollect, Parser};
 use rustc_parse::{self, new_parser_from_file};
 use rustc_session::lint::builtin::INCOMPLETE_INCLUDE;
 use rustc_span::symbol::Symbol;
-use rustc_span::{self, FileName, Pos, Span};
+use rustc_span::{self, Pos, Span};
 
 use smallvec::SmallVec;
-use std::path::PathBuf;
 use std::rc::Rc;
 
 // These macros all relate to the file system; they either return
@@ -104,7 +102,7 @@ pub fn expand_include<'cx>(
         return DummyResult::any(sp);
     };
     // The file will be added to the code map by the parser
-    let file = match resolve_path(cx, file.as_str(), sp) {
+    let file = match resolve_path(&cx.sess.parse_sess, file.as_str(), sp) {
         Ok(f) => f,
         Err(mut err) => {
             err.emit();
@@ -176,7 +174,7 @@ pub fn expand_include_str(
     let Some(file) = get_single_str_from_tts(cx, sp, tts, "include_str!") else {
         return DummyResult::any(sp);
     };
-    let file = match resolve_path(cx, file.as_str(), sp) {
+    let file = match resolve_path(&cx.sess.parse_sess, file.as_str(), sp) {
         Ok(f) => f,
         Err(mut err) => {
             err.emit();
@@ -210,7 +208,7 @@ pub fn expand_include_bytes(
     let Some(file) = get_single_str_from_tts(cx, sp, tts, "include_bytes!") else {
         return DummyResult::any(sp);
     };
-    let file = match resolve_path(cx, file.as_str(), sp) {
+    let file = match resolve_path(&cx.sess.parse_sess, file.as_str(), sp) {
         Ok(f) => f,
         Err(mut err) => {
             err.emit();
@@ -225,40 +223,3 @@ pub fn expand_include_bytes(
         }
     }
 }
-
-/// Resolves a `path` mentioned inside Rust code, returning an absolute path.
-///
-/// This unifies the logic used for resolving `include_X!`.
-fn resolve_path<'a>(
-    cx: &mut ExtCtxt<'a>,
-    path: impl Into<PathBuf>,
-    span: Span,
-) -> PResult<'a, PathBuf> {
-    let path = path.into();
-
-    // Relative paths are resolved relative to the file in which they are found
-    // after macro expansion (that is, they are unhygienic).
-    if !path.is_absolute() {
-        let callsite = span.source_callsite();
-        let mut result = match cx.source_map().span_to_filename(callsite) {
-            FileName::Real(name) => name
-                .into_local_path()
-                .expect("attempting to resolve a file path in an external file"),
-            FileName::DocTest(path, _) => path,
-            other => {
-                return Err(cx.struct_span_err(
-                    span,
-                    &format!(
-                        "cannot resolve relative path in non-file source `{}`",
-                        cx.source_map().filename_for_diagnostics(&other)
-                    ),
-                ));
-            }
-        };
-        result.pop();
-        result.push(path);
-        Ok(result)
-    } else {
-        Ok(path)
-    }
-}

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -5,7 +5,7 @@ use rustc_data_structures::memmap::Mmap;
 use rustc_data_structures::temp_dir::MaybeTempDir;
 use rustc_errors::{ErrorGuaranteed, Handler};
 use rustc_fs_util::fix_windows_verbatim_for_gcc;
-use rustc_hir::def_id::CrateNum;
+use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
 use rustc_middle::middle::dependency_format::Linkage;
 use rustc_middle::middle::exported_symbols::SymbolExportKind;
 use rustc_session::config::{self, CFGuard, CrateType, DebugInfo, LdImpl, Strip};
@@ -2099,8 +2099,14 @@ fn add_order_independent_options(
     // Pass optimization flags down to the linker.
     cmd.optimize();
 
+    let debugger_visualizer_paths = if sess.target.is_like_msvc {
+        collect_debugger_visualizers(tmpdir, sess, &codegen_results.crate_info)
+    } else {
+        Vec::new()
+    };
+
     // Pass debuginfo and strip flags down to the linker.
-    cmd.debuginfo(strip_value(sess));
+    cmd.debuginfo(strip_value(sess), &debugger_visualizer_paths);
 
     // We want to prevent the compiler from accidentally leaking in any system libraries,
     // so by default we tell linkers not to link to any default libraries.
@@ -2119,6 +2125,47 @@ fn add_order_independent_options(
     add_rpath_args(cmd, sess, codegen_results, out_filename);
 }
 
+// Write the debugger visualizer files for each crate to the temp directory and gather the file paths.
+fn collect_debugger_visualizers(
+    tmpdir: &Path,
+    sess: &Session,
+    crate_info: &CrateInfo,
+) -> Vec<PathBuf> {
+    let mut visualizer_paths = Vec::new();
+    let debugger_visualizers = &crate_info.debugger_visualizers;
+    let mut index = 0;
+
+    for (&cnum, visualizers) in debugger_visualizers {
+        let crate_name = if cnum == LOCAL_CRATE {
+            crate_info.local_crate_name.as_str()
+        } else {
+            crate_info.crate_name[&cnum].as_str()
+        };
+
+        for visualizer in visualizers {
+            let visualizer_out_file = tmpdir.join(format!("{}-{}.natvis", crate_name, index));
+
+            match fs::write(&visualizer_out_file, &visualizer.src) {
+                Ok(()) => {
+                    visualizer_paths.push(visualizer_out_file.clone());
+                    index += 1;
+                }
+                Err(error) => {
+                    sess.warn(
+                        format!(
+                            "Unable to write debugger visualizer file `{}`: {} ",
+                            visualizer_out_file.display(),
+                            error
+                        )
+                        .as_str(),
+                    );
+                }
+            };
+        }
+    }
+    visualizer_paths
+}
+
 /// # Native library linking
 ///
 /// User-supplied library search paths (-L on the command line). These are the same paths used to

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -183,7 +183,7 @@ pub trait Linker {
     fn optimize(&mut self);
     fn pgo_gen(&mut self);
     fn control_flow_guard(&mut self);
-    fn debuginfo(&mut self, strip: Strip);
+    fn debuginfo(&mut self, strip: Strip, debugger_visualizers: &[PathBuf]);
     fn no_crt_objects(&mut self);
     fn no_default_libraries(&mut self);
     fn export_symbols(&mut self, tmpdir: &Path, crate_type: CrateType, symbols: &[String]);
@@ -611,7 +611,7 @@ impl<'a> Linker for GccLinker<'a> {
 
     fn control_flow_guard(&mut self) {}
 
-    fn debuginfo(&mut self, strip: Strip) {
+    fn debuginfo(&mut self, strip: Strip, _: &[PathBuf]) {
         // MacOS linker doesn't support stripping symbols directly anymore.
         if self.sess.target.is_like_osx {
             return;
@@ -915,7 +915,7 @@ impl<'a> Linker for MsvcLinker<'a> {
         self.cmd.arg("/guard:cf");
     }
 
-    fn debuginfo(&mut self, strip: Strip) {
+    fn debuginfo(&mut self, strip: Strip, debugger_visualizers: &[PathBuf]) {
         match strip {
             Strip::None => {
                 // This will cause the Microsoft linker to generate a PDB file
@@ -942,6 +942,13 @@ impl<'a> Linker for MsvcLinker<'a> {
                         }
                     }
                 }
+
+                // This will cause the Microsoft linker to embed .natvis info for all crates into the PDB file
+                for path in debugger_visualizers {
+                    let mut arg = OsString::from("/NATVIS:");
+                    arg.push(path);
+                    self.cmd.arg(arg);
+                }
             }
             Strip::Debuginfo | Strip::Symbols => {
                 self.cmd.arg("/DEBUG:NONE");
@@ -1124,7 +1131,7 @@ impl<'a> Linker for EmLinker<'a> {
 
     fn control_flow_guard(&mut self) {}
 
-    fn debuginfo(&mut self, _strip: Strip) {
+    fn debuginfo(&mut self, _strip: Strip, _: &[PathBuf]) {
         // Preserve names or generate source maps depending on debug info
         self.cmd.arg(match self.sess.opts.debuginfo {
             DebugInfo::None => "-g0",
@@ -1315,7 +1322,7 @@ impl<'a> Linker for WasmLd<'a> {
 
     fn pgo_gen(&mut self) {}
 
-    fn debuginfo(&mut self, strip: Strip) {
+    fn debuginfo(&mut self, strip: Strip, _: &[PathBuf]) {
         match strip {
             Strip::None => {}
             Strip::Debuginfo => {
@@ -1450,7 +1457,7 @@ impl<'a> Linker for L4Bender<'a> {
 
     fn pgo_gen(&mut self) {}
 
-    fn debuginfo(&mut self, strip: Strip) {
+    fn debuginfo(&mut self, strip: Strip, _: &[PathBuf]) {
         match strip {
             Strip::None => {}
             Strip::Debuginfo => {
@@ -1600,7 +1607,7 @@ impl<'a> Linker for PtxLinker<'a> {
         self.cmd.arg("-L").arg(path);
     }
 
-    fn debuginfo(&mut self, _strip: Strip) {
+    fn debuginfo(&mut self, _strip: Strip, _: &[PathBuf]) {
         self.cmd.arg("--debug");
     }
 
@@ -1699,7 +1706,7 @@ impl<'a> Linker for BpfLinker<'a> {
         self.cmd.arg("-L").arg(path);
     }
 
-    fn debuginfo(&mut self, _strip: Strip) {
+    fn debuginfo(&mut self, _strip: Strip, _: &[PathBuf]) {
         self.cmd.arg("--debug");
     }
 

compiler/rustc_codegen_ssa/src/base.rs

@@ -847,7 +847,13 @@ impl CrateInfo {
             missing_lang_items: Default::default(),
             dependency_formats: tcx.dependency_formats(()).clone(),
             windows_subsystem,
+            debugger_visualizers: Default::default(),
         };
+        let debugger_visualizers = tcx.debugger_visualizers(LOCAL_CRATE).clone();
+        if !debugger_visualizers.is_empty() {
+            info.debugger_visualizers.insert(LOCAL_CRATE, debugger_visualizers);
+        }
+
         let lang_items = tcx.lang_items();
 
         let crates = tcx.crates(());
@@ -862,7 +868,9 @@ impl CrateInfo {
             info.native_libraries
                 .insert(cnum, tcx.native_libraries(cnum).iter().map(Into::into).collect());
             info.crate_name.insert(cnum, tcx.crate_name(cnum));
-            info.used_crate_source.insert(cnum, tcx.used_crate_source(cnum).clone());
+
+            let used_crate_source = tcx.used_crate_source(cnum);
+            info.used_crate_source.insert(cnum, used_crate_source.clone());
             if tcx.is_compiler_builtins(cnum) {
                 info.compiler_builtins = Some(cnum);
             }
@@ -883,6 +891,14 @@ impl CrateInfo {
             let missing =
                 missing.iter().cloned().filter(|&l| lang_items::required(tcx, l)).collect();
             info.missing_lang_items.insert(cnum, missing);
+
+            // Only include debugger visualizer files from crates that will be statically linked.
+            if used_crate_source.rlib.is_some() || used_crate_source.rmeta.is_some() {
+                let debugger_visualizers = tcx.debugger_visualizers(cnum).clone();
+                if !debugger_visualizers.is_empty() {
+                    info.debugger_visualizers.insert(cnum, debugger_visualizers);
+                }
+            }
         }
 
         info

compiler/rustc_codegen_ssa/src/lib.rs

@@ -36,6 +36,7 @@ use rustc_session::config::{CrateType, OutputFilenames, OutputType, RUST_CGU_EXT
 use rustc_session::cstore::{self, CrateSource};
 use rustc_session::utils::NativeLibKind;
 use rustc_span::symbol::Symbol;
+use rustc_span::DebuggerVisualizerFile;
 use std::path::{Path, PathBuf};
 
 pub mod back;
@@ -157,6 +158,7 @@ pub struct CrateInfo {
     pub missing_lang_items: FxHashMap<CrateNum, Vec<LangItem>>,
     pub dependency_formats: Lrc<Dependencies>,
     pub windows_subsystem: Option<String>,
+    pub debugger_visualizers: FxHashMap<CrateNum, Vec<DebuggerVisualizerFile>>,
 }
 
 #[derive(Encodable, Decodable)]

compiler/rustc_expand/src/base.rs

@@ -10,7 +10,7 @@ use rustc_ast::{self as ast, AstLike, Attribute, Item, NodeId, PatKind};
 use rustc_attr::{self as attr, Deprecation, Stability};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::{self, Lrc};
-use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, MultiSpan};
+use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, MultiSpan, PResult};
 use rustc_lint_defs::builtin::PROC_MACRO_BACK_COMPAT;
 use rustc_lint_defs::BuiltinLintDiagnostics;
 use rustc_parse::{self, nt_to_tokenstream, parser, MACRO_ARGUMENTS};
@@ -20,7 +20,7 @@ use rustc_span::edition::Edition;
 use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId};
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
-use rustc_span::{Span, DUMMY_SP};
+use rustc_span::{FileName, Span, DUMMY_SP};
 use smallvec::{smallvec, SmallVec};
 
 use std::default::Default;
@@ -1136,6 +1136,43 @@ impl<'a> ExtCtxt<'a> {
     }
 }
 
+/// Resolves a `path` mentioned inside Rust code, returning an absolute path.
+///
+/// This unifies the logic used for resolving `include_X!`.
+pub fn resolve_path(
+    parse_sess: &ParseSess,
+    path: impl Into<PathBuf>,
+    span: Span,
+) -> PResult<'_, PathBuf> {
+    let path = path.into();
+
+    // Relative paths are resolved relative to the file in which they are found
+    // after macro expansion (that is, they are unhygienic).
+    if !path.is_absolute() {
+        let callsite = span.source_callsite();
+        let mut result = match parse_sess.source_map().span_to_filename(callsite) {
+            FileName::Real(name) => name
+                .into_local_path()
+                .expect("attempting to resolve a file path in an external file"),
+            FileName::DocTest(path, _) => path,
+            other => {
+                return Err(parse_sess.span_diagnostic.struct_span_err(
+                    span,
+                    &format!(
+                        "cannot resolve relative path in non-file source `{}`",
+                        parse_sess.source_map().filename_for_diagnostics(&other)
+                    ),
+                ));
+            }
+        };
+        result.pop();
+        result.push(path);
+        Ok(result)
+    } else {
+        Ok(path)
+    }
+}
+
 /// Extracts a string literal from the macro expanded version of `expr`,
 /// returning a diagnostic error of `err_msg` if `expr` is not a string literal.
 /// The returned bool indicates whether an applicable suggestion has already been

compiler/rustc_feature/src/active.rs

@@ -358,6 +358,8 @@ declare_features! (
     (active, custom_inner_attributes, "1.30.0", Some(54726), None),
     /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`.
     (active, custom_test_frameworks, "1.30.0", Some(50297), None),
+    /// Allows using `#[debugger_visualizer]`.
+    (active, debugger_visualizer, "1.62.0", Some(95939), None),
     /// Allows declarative macros 2.0 (`macro`).
     (active, decl_macro, "1.17.0", Some(39412), None),
     /// Allows rustc to inject a default alloc_error_handler

compiler/rustc_feature/src/builtin_attrs.rs

@@ -379,6 +379,12 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     // Unstable attributes:
     // ==========================================================================
 
+    // RFC #3191: #[debugger_visualizer] support
+    gated!(
+        debugger_visualizer, Normal, template!(List: r#"natvis_file = "...""#),
+        DuplicatesOk, experimental!(debugger_visualizer)
+    ),
+
     // Linking:
     gated!(naked, Normal, template!(Word), WarnFollowing, naked_functions, experimental!(naked)),
     gated!(