[clang] 76a55d3 - [KeyInstr][Clang] Scalar init atom (#134633)

[via cfe-commits]

Author: Orlando Cazalet-Hyams
Date: 2025-05-22T12:50:10+01:00
New Revision: 76a55d3860f76c15ca51d188e10e4352fecf61e9

URL: https://github.com/llvm/llvm-project/commit/76a55d3860f76c15ca51d188e10e4352fecf61e9
DIFF: https://github.com/llvm/llvm-project/commit/76a55d3860f76c15ca51d188e10e4352fecf61e9.diff

LOG: [KeyInstr][Clang] Scalar init atom (#134633)

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.

Added: 
    clang/test/DebugInfo/KeyInstructions/init-scalar.c

Modified: 
    clang/lib/CodeGen/CGDecl.cpp
    clang/lib/CodeGen/CGExpr.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 4a8f7f6a42ecb..d02f2ad09d2f1 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -1925,6 +1925,7 @@ void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
 
   const VarDecl &D = *emission.Variable;
   auto DL = ApplyDebugLocation::CreateDefaultArtificial(*this, D.getLocation());
+  ApplyAtomGroup Grp(getDebugInfo());
   QualType type = D.getType();
 
   // If this local has an initializer, emit it now.

diff  --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 11365d278a1e0..7cb7ee20fcf6a 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -2222,6 +2222,8 @@ void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
   }
 
   llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
+  addInstToCurrentSourceAtom(Store, Value);
+
   if (isNontemporal) {
     llvm::MDNode *Node =
         llvm::MDNode::get(Store->getContext(),

diff  --git a/clang/test/DebugInfo/KeyInstructions/init-scalar.c b/clang/test/DebugInfo/KeyInstructions/init-scalar.c
new file mode 100644
index 0000000000000..a86c029e47e8c
--- /dev/null
+++ b/clang/test/DebugInfo/KeyInstructions/init-scalar.c
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -gkey-instructions -x c++ %s -debug-info-kind=line-tables-only -emit-llvm -o - \
+// RUN: | FileCheck %s --implicit-check-not atomGroup --implicit-check-not atomRank
+
+// RUN: %clang_cc1 -gkey-instructions -x c %s -debug-info-kind=line-tables-only -emit-llvm -o - \
+// RUN: | FileCheck %s --implicit-check-not atomGroup --implicit-check-not atomRank
+
+void a() {
+// CHECK: store i32 0, ptr %A{{.*}}, !dbg [[G1R1:!.*]]
+    int A = 0;
+// CHECK: %add = add {{.*}}, !dbg [[G2R2:!.*]]
+// CHECK: store i32 %add, ptr %B, align 4, !dbg [[G2R1:!.*]]
+    int B = 2 * A + 1;
+}
+
+// CHECK: [[G1R1]] = !DILocation({{.*}}, atomGroup: 1, atomRank: 1)
+// CHECK: [[G2R2]] = !DILocation({{.*}}, atomGroup: 2, atomRank: 2)
+// CHECK: [[G2R1]] = !DILocation({{.*}}, atomGroup: 2, atomRank: 1)