[DebugInfo] Helper method for finding the deepest inlining location

[akshayrdeodhar]

DebugInfoMetadata.h has a way to reach the scope of the deepest caller location, but not to the location itself. Having it is handy for debugging and debug printing.

[llvmbot]

@llvm/pr-subscribers-llvm-ir

@llvm/pr-subscribers-debuginfo

Author: Akshay Deodhar (akshayrdeodhar)

Changes

DebugInfoMetadata.h has a way to reach the scope of the deepest caller location, but not to the location itself. Having it is handy for debugging and debug printing.

---

Full diff: https://github.com/llvm/llvm-project/pull/161696.diff

1 Files Affected:

• (modified) llvm/include/llvm/IR/DebugInfoMetadata.h (+12-3)

diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
index 6652e303a6648..d63e71d246fe0 100644
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -2600,14 +2600,23 @@ class DILocation : public MDNode {
   StringRef getDirectory() const { return getScope()->getDirectory(); }
   std::optional<StringRef> getSource() const { return getScope()->getSource(); }
 
+
+  /// Get the location where this is inlined
+  ///
+  /// Walk through \a getInlinedAt() and return the \a DILocation where this is inlined.
+  DILocation *getInlinedAtLocation() const {
+    DILocation *Current = this, Next = nullptr;
+    while (Next = Current->getInlinedAt())
+      Current = Next;
+    return Current;
+  }
+
   /// Get the scope where this is inlined.
   ///
   /// Walk through \a getInlinedAt() and return \a getScope() from the deepest
   /// location.
   DILocalScope *getInlinedAtScope() const {
-    if (auto *IA = getInlinedAt())
-      return IA->getInlinedAtScope();
-    return getScope();
+    return getInlinedAtLocation()->getScope();
   }
 
   /// Get the DWARF discriminator.

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[OCHyams]

SGTM, I'm surprised this doesn't already exist.

Could you add some unittest coverage? getInlinedAtScope doesn't look particularly well covered as is, but is at least called in llvm/unittests/Transforms/Utils/CloningTest.cpp - checking multiple levels of inlining would probably be ideal, but doing something similar to the getInlinedAtScope should probably be a minimum.

[akshayrdeodhar]

Could you add some unittest coverage?

I'm planning to add a test to DebugInfoTest.cpp- does that work?

[OCHyams]

LGTM with a couple nits