From 638b319d13527540a84dc7553ce8a1727a06392e Mon Sep 17 00:00:00 2001
From: Orlando Cazalet-Hyams <orlando.hyams@sony.com>
Date: Thu, 3 Apr 2025 17:31:32 +0100
Subject: [PATCH] [KeyInstr][Clang] Catch variable init atom
This patch is part of a stack that teaches Clang to generate Key Instructions
metadata for C and C++.
The Key Instructions project is introduced, including a "quick summary" section
at the top which adds context for this PR, here:
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.
The Clang-side work is demoed here:
https://github.com/llvm/llvm-project/pull/130943
---
clang/lib/CodeGen/ItaniumCXXABI.cpp | 1 +
clang/test/KeyInstructions/try-catch.cpp | 20 ++++++++++++++++++++
2 files changed, 21 insertions(+)
create mode 100644 clang/test/KeyInstructions/try-catch.cpp
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 77e995b4c933..b3f1e208fa31 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -5051,6 +5051,7 @@ void ItaniumCXXABI::emitBeginCatch(CodeGenFunction &CGF,
// Emit the local.
CodeGenFunction::AutoVarEmission var = CGF.EmitAutoVarAlloca(*CatchParam);
+ ApplyAtomGroup Grp(CGF.getDebugInfo());
InitCatchParam(CGF, *CatchParam, var.getObjectAddress(CGF), S->getBeginLoc());
CGF.EmitAutoVarCleanups(var);
}
diff --git a/clang/test/KeyInstructions/try-catch.cpp b/clang/test/KeyInstructions/try-catch.cpp
new file mode 100644
index 000000000000..3d1080aca2f0
--- /dev/null
+++ b/clang/test/KeyInstructions/try-catch.cpp
@@ -0,0 +1,20 @@
+// RUN: %clang -gkey-instructions %s -gmlt -S -emit-llvm -o - -fexceptions \
+// RUN: | FileCheck %s
+
+void except() {
+ // FIXME(OCH): Should `store i32 32, ptr %exception` be key?
+ throw 32;
+}
+
+void attempt() {
+ try { except(); }
+// CHECK: catch:
+// CHECK: %4 = call ptr @__cxa_begin_catch(ptr %exn)
+// CHECK: %5 = load i32{{.*}}, !dbg [[G1R2:!.*]]
+// CHECK: store i32 %5, ptr %e{{.*}}, !dbg [[G1R1:!.*]]
+// CHECK: call void @__cxa_end_catch()
+ catch (int e) { }
+}
+
+// CHECK: [[G1R2]] = !DILocation({{.*}}, atomGroup: 1, atomRank: 2)
+// CHECK: [[G1R1]] = !DILocation({{.*}}, atomGroup: 1, atomRank: 1)