[NFC][Cloning] Make ClonedModule case more obvious in CollectDebugInfoForCloning

[artempyanykh]

Stacked PRs:

• [NFC][Cloning] Move DebugInfoFinder decl closer to its place of usage #129154
• [NFC][Cloning] Clean up comments in CloneFunctionInto #129153
• [NFC][Cloning] Remove now unused CollectDebugInfoForCloning #129152
• [NFC][Cloning] Remove now unused FindDebugInfoToIdentityMap #129151
• [NFC][Coro] Remove now unused CommonDebugInfo in CoroSplit #129150
• [NFC][Coro] Use CloneFunctionInto for coroutine cloning instead of CloneFunction<Part> #129149
• [NFC][Cloning] Replace DIFinder usage in CloneFunctionInto with a MetadataPredicate #129148
• [NFC][Cloning] Replace IdentityMD set with a predicate in ValueMapper #129147
• [NFC][Cloning] Make DifferentModule case more obvious in CollectDebugInfoForCloning #129146
• [NFC][Cloning] Add a helper to collect debug info from instructions #129145
• [NFC][Cloning] Simplify the flow in FindDebugInfoToIdentityMap #129144
• ->[NFC][Cloning] Make ClonedModule case more obvious in CollectDebugInfoForCloning #129143

---

[NFC][Cloning] Make ClonedModule case more obvious in CollectDebugInfoForCloning

Summary:
The code's behavior is unchanged, but it's more obvious right now.

Test Plan:
ninja check-llvm-unit check-llvm

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Artem Pianykh (artempyanykh)

Changes

[NFC][Cloning] Make ClonedModule case more obvious in CollectDebugInfoForCloning

Summary:
The code's behavior is unchanged, but it's more obvious right now.

Test Plan:
ninja check-llvm-unit check-llvm

---

Full diff: https://github.com/llvm/llvm-project/pull/129143.diff

1 Files Affected:

• (modified) llvm/lib/Transforms/Utils/CloneFunction.cpp (+5-1)

diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index 58d400ac396be..9267930027c04 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -135,6 +135,10 @@ void llvm::CloneFunctionAttributesInto(Function *NewFunc,
 DISubprogram *llvm::CollectDebugInfoForCloning(const Function &F,
                                                CloneFunctionChangeType Changes,
                                                DebugInfoFinder &DIFinder) {
+  // CloneModule takes care of cloning debug info.
+  if (Changes == CloneFunctionChangeType::ClonedModule)
+    return nullptr;
+
   DISubprogram *SPClonedWithinModule = nullptr;
   if (Changes < CloneFunctionChangeType::DifferentModule) {
     SPClonedWithinModule = F.getSubprogram();
@@ -143,7 +147,7 @@ DISubprogram *llvm::CollectDebugInfoForCloning(const Function &F,
     DIFinder.processSubprogram(SPClonedWithinModule);
 
   const Module *M = F.getParent();
-  if (Changes != CloneFunctionChangeType::ClonedModule && M) {
+  if (M) {
     // Inspect instructions to process e.g. DILexicalBlocks of inlined functions
     for (const auto &I : instructions(F))
       DIFinder.processInstruction(*M, I);