debuginfo: embed gdb visualizers in module

src/debuginfo/emit.rs

@@ -35,6 +35,23 @@ impl DebugContext {
             }
             Ok(())
         });
+
+        self.add_gdb_debugger_visualizers(product);
+    }
+
+    fn add_gdb_debugger_visualizers(&mut self, product: &mut ObjectProduct) {
+        let mut section = WriterRelocate::new(self.endian);
+        section.write(b"\x01gdb_load_rust_pretty_printers.py\0").unwrap();
+
+        for (index, visualizer) in self.gdb_visualizers.iter().enumerate() {
+            let vis_name = format!("\x04pretty-printer-{}-{index}\n", self.crate_name);
+
+            section.write(vis_name.as_bytes()).unwrap();
+            section.write(&visualizer.src).unwrap();
+
+            section.write(b"\0").unwrap();
+        }
+        product.add_gdb_visualizers_section(section.writer.take());
     }
 }
 

src/debuginfo/mod.rs

@@ -5,6 +5,8 @@ mod line_info;
 mod object;
 mod unwind;
 
+use std::collections::BTreeSet;
+
 use cranelift_codegen::ir::Endianness;
 use cranelift_codegen::isa::TargetIsa;
 use gimli::write::{
@@ -13,6 +15,8 @@ use gimli::write::{
 };
 use gimli::{Encoding, Format, LineEncoding, RunTimeEndian};
 use indexmap::IndexSet;
+use rustc_codegen_ssa::base::collect_debugger_visualizers_transitive;
+use rustc_middle::middle::debugger_visualizer::{DebuggerVisualizerFile, DebuggerVisualizerType};
 use rustc_session::Session;
 
 pub(crate) use self::emit::{DebugReloc, DebugRelocName};
@@ -30,6 +34,8 @@ pub(crate) struct DebugContext {
     unit_range_list: RangeList,
 
     should_remap_filepaths: bool,
+    gdb_visualizers: BTreeSet<DebuggerVisualizerFile>,
+    crate_name: String,
 }
 
 pub(crate) struct FunctionDebugContext {
@@ -60,6 +66,10 @@ impl DebugContext {
             Endianness::Big => RunTimeEndian::Big,
         };
 
+        let crate_name = tcx.crate_name(LOCAL_CRATE).to_string();
+        let gdb_visualizers =
+            collect_debugger_visualizers_transitive(tcx, DebuggerVisualizerType::GdbPrettyPrinter);
+
         let mut dwarf = DwarfUnit::new(encoding);
 
         let should_remap_filepaths = tcx.sess.should_prefer_remapped_for_codegen();
@@ -80,7 +90,7 @@ impl DebugContext {
                 let name = path.to_string_lossy().into_owned();
                 (name, None)
             }
-            None => (tcx.crate_name(LOCAL_CRATE).to_string(), None),
+            None => (crate_name.clone(), None),
         };
 
         let mut line_program = LineProgram::new(
@@ -112,6 +122,8 @@ impl DebugContext {
             dwarf,
             unit_range_list: RangeList(Vec::new()),
             should_remap_filepaths,
+            gdb_visualizers,
+            crate_name
         }
     }
 

src/debuginfo/object.rs

@@ -11,6 +11,7 @@ pub(super) trait WriteDebugInfo {
     type SectionId: Copy;
 
     fn add_debug_section(&mut self, name: SectionId, data: Vec<u8>) -> Self::SectionId;
+    fn add_gdb_visualizers_section(&mut self, data: Vec<u8>) -> Self::SectionId;
     fn add_debug_reloc(
         &mut self,
         section_map: &FxHashMap<SectionId, Self::SectionId>,
@@ -22,6 +23,18 @@ pub(super) trait WriteDebugInfo {
 impl WriteDebugInfo for ObjectProduct {
     type SectionId = (object::write::SectionId, object::write::SymbolId);
 
+    fn add_gdb_visualizers_section(
+        &mut self,
+        data: Vec<u8>,
+    ) -> (object::write::SectionId, object::write::SymbolId) {
+        let segment = self.object.segment_name(StandardSegment::Debug).to_vec();
+        let section_id =
+            self.object.add_section(segment, b".debug_gdb_scripts".to_vec(), SectionKind::Debug);
+        self.object.section_mut(section_id).set_data(data, 1);
+        let symbol_id = self.object.section_symbol(section_id);
+        (section_id, symbol_id)
+    }
+
     fn add_debug_section(
         &mut self,
         id: SectionId,