Preserve, clarify, and extend debug information

`-Cdebuginfo=1` was never line tables only and
can't be due to backwards compatibility issues.
This was clarified and an option for line tables only
was added. Additionally an option for line info
directives only was added, which is well needed for
some targets. The debug info options should now
behave the same as clang's debug info options.

3 files changed, 6 insertions, 21 deletions

diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index e2a592d851a..4bf6762d1f6 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -830,24 +830,7 @@ pub fn build_compile_unit_di_node<'ll, 'tcx>(
     }
     .unwrap_or_default();
     let split_name = split_name.to_str().unwrap();
-
-    // FIXME(#60020):
-    //
-    //    This should actually be
-    //
-    //        let kind = DebugEmissionKind::from_generic(tcx.sess.opts.debuginfo);
-    //
-    //    That is, we should set LLVM's emission kind to `LineTablesOnly` if
-    //    we are compiling with "limited" debuginfo. However, some of the
-    //    existing tools relied on slightly more debuginfo being generated than
-    //    would be the case with `LineTablesOnly`, and we did not want to break
-    //    these tools in a "drive-by fix", without a good idea or plan about
-    //    what limited debuginfo should exactly look like. So for now we keep
-    //    the emission kind as `FullDebug`.
-    //
-    //    See https://github.com/rust-lang/rust/issues/60020 for details.
-    let kind = DebugEmissionKind::FullDebug;
-    assert!(tcx.sess.opts.debuginfo != DebugInfo::None);
+    let kind = DebugEmissionKind::from_generic(tcx.sess.opts.debuginfo);
 
     unsafe {
         let compile_unit_file = llvm::LLVMRustDIBuilderCreateFile(
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index 5392534cfcb..41a75c9d775 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -402,7 +402,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             cx: &CodegenCx<'ll, 'tcx>,
             fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
         ) -> &'ll DIArray {
-            if cx.sess().opts.debuginfo == DebugInfo::Limited {
+            if cx.sess().opts.debuginfo != DebugInfo::Full {
                 return create_DIArray(DIB(cx), &[]);
             }
 
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 0d63e634ad8..aff352abab4 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -946,6 +946,7 @@ pub mod debuginfo {
         NoDebug,
         FullDebug,
         LineTablesOnly,
+        DebugDirectivesOnly,
     }
 
     impl DebugEmissionKind {
@@ -953,8 +954,9 @@ pub mod debuginfo {
             use rustc_session::config::DebugInfo;
             match kind {
                 DebugInfo::None => DebugEmissionKind::NoDebug,
-                DebugInfo::Limited => DebugEmissionKind::LineTablesOnly,
-                DebugInfo::Full => DebugEmissionKind::FullDebug,
+                DebugInfo::LineDirectivesOnly => DebugEmissionKind::DebugDirectivesOnly,
+                DebugInfo::LineTablesOnly => DebugEmissionKind::LineTablesOnly,
+                DebugInfo::Limited | DebugInfo::Full => DebugEmissionKind::FullDebug,
             }
         }
     }