[KeyInstr][Clang] Add ApplyAtomGroup (#134632)

This is a scoped helper similar to ApplyDebugLocation that creates a new source
location atom group which instructions can be added to.

A source atom is a source construct that is "interesting" for debug stepping
purposes. We use an atom group number to track the instruction(s) that implement
the functionality for the atom, plus backup instructions/source locations.

This patch is part of a stack that teaches Clang to generate Key Instructions
metadata for C and C++.

RFC:
https://discourse.llvm.org/t/rfc-improving-is-stmt-placement-for-better-interactive-debugging/82668

The feature is only functional in LLVM if LLVM is built with CMake flag
LLVM_EXPERIMENTAL_KEY_INSTRUCTIONs. Eventually that flag will be removed.

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 603e38d..1743f558 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -1740,6 +1740,14 @@ public:
   /// recently incremented counter.
   uint64_t getCurrentProfileCount() { return PGO.getCurrentRegionCount(); }
 
+  /// See CGDebugInfo::addInstToCurrentSourceAtom.
+  void addInstToCurrentSourceAtom(llvm::Instruction *KeyInstruction,
+                                  llvm::Value *Backup);
+
+  /// See CGDebugInfo::addInstToSpecificSourceAtom.
+  void addInstToSpecificSourceAtom(llvm::Instruction *KeyInstruction,
+                                   llvm::Value *Backup, uint64_t Atom);
+
 private:
   /// SwitchInsn - This is nearest current switch instruction. It is null if
   /// current context is not in a switch.