[clang] [CIR] Implement reference type in init catch param (PR #184442)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Amr Hesham (AmrDeveloper)

<details>
<summary>Changes</summary>

Implement init support for reference type in the init catch param

---
Full diff: https://github.com/llvm/llvm-project/pull/184442.diff


2 Files Affected:

- (modified) clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp (+17-1) 
- (modified) clang/test/CIR/CodeGen/try-catch-tmp.cpp (+64) 


``````````diff
diff --git a/clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp b/clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp
index f195b9325a41c..b8516f85e5051 100644
--- a/clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp
@@ -2385,7 +2385,23 @@ static void initCatchParam(CIRGenFunction &cgf, mlir::Value ehToken,
   // If we're catching by reference, we can just cast the object
   // pointer to the appropriate pointer.
   if (isa<ReferenceType>(catchType)) {
-    cgf.cgm.errorNYI(loc, "initCatchParam: ReferenceType");
+    QualType caughtType = cast<ReferenceType>(catchType)->getPointeeType();
+    bool endCatchMightThrow = caughtType->isRecordType();
+
+    mlir::Value adjustedExn =
+        callBeginCatch(cgf, ehToken, cirCatchTy, endCatchMightThrow);
+
+    // We have no way to tell the personality function that we're
+    // catching by reference, so if we're catching a pointer,
+    // __cxa_begin_catch will actually return that pointer by value.
+    if (isa<PointerType>(caughtType)) {
+      cgf.cgm.errorNYI(loc, "initCatchParam: catching a pointer");
+      return;
+    }
+
+    mlir::Value exnCast =
+        cgf.getBuilder().createBitcast(adjustedExn, cirCatchTy);
+    cgf.getBuilder().createStore(cgf.getLoc(loc), exnCast, paramAddr);
     return;
   }
 
diff --git a/clang/test/CIR/CodeGen/try-catch-tmp.cpp b/clang/test/CIR/CodeGen/try-catch-tmp.cpp
index 5cb60aaf6b2cc..405f54c41885c 100644
--- a/clang/test/CIR/CodeGen/try-catch-tmp.cpp
+++ b/clang/test/CIR/CodeGen/try-catch-tmp.cpp
@@ -119,6 +119,70 @@ void call_function_inside_try_catch_with_exception_type() {
 // OGCG:   %[[EXCEPTION_INFO:.*]] = insertvalue { ptr, i32 } %[[TMP_EXCEPTION_INFO]], i32 %[[TMP_EH_TYPE_ID]], 1
 // OGCG:   resume { ptr, i32 } %[[EXCEPTION_INFO]]
 
+void call_function_inside_try_catch_with_ref_exception_type() {
+  try {
+    division();
+  } catch (int &ref) {
+  }
+}
+
+// CIR: cir.func {{.*}} @_Z54call_function_inside_try_catch_with_ref_exception_typev() personality(@__gxx_personality_v0)
+// CIR: cir.scope {
+// CIR:   %[[EXCEPTION_ADDR:.*]] = cir.alloca !cir.ptr<!s32i>, !cir.ptr<!cir.ptr<!s32i>>, ["ref", const]
+// CIR:   cir.try {
+// CIR:     %[[CALL:.*]] = cir.call @_Z8divisionv()
+// CIR:     cir.yield
+// CIR:   } catch [type #cir.global_view<@_ZTIi> : !cir.ptr<!u8i>] (%{{.*}}: !cir.eh_token {{.*}}) {
+// CIR:     %[[CATCH_TOKEN:.*]], %[[EXN_PTR:.*]] = cir.begin_catch %{{.*}} : !cir.eh_token -> (!cir.catch_token, !cir.ptr<!s32i>)
+// CIR:     cir.cleanup.scope {
+// CIR:       cir.store {{.*}} %[[EXN_PTR]], %[[EXCEPTION_ADDR]] : !cir.ptr<!s32i>, !cir.ptr<!cir.ptr<!s32i>>
+// CIR:       cir.yield
+// CIR:     } cleanup all {
+// CIR:       cir.end_catch %[[CATCH_TOKEN]] : !cir.catch_token
+// CIR:       cir.yield
+// CIR:     }
+// CIR:     cir.yield
+// CIR:   } unwind (%{{.*}}: !cir.eh_token {{.*}}) {
+// CIR:     cir.resume %{{.*}} : !cir.eh_token
+// CIR:   }
+// CIR: }
+
+// OGCG: define {{.*}} void @_Z54call_function_inside_try_catch_with_ref_exception_typev() #0 personality ptr @__gxx_personality_v0
+// OGCG:   %[[EXCEPTION_ADDR:.*]] = alloca ptr, align 8
+// OGCG:   %[[EH_TYPE_ID_ADDR:.*]] = alloca i32, align 4
+// OGCG:   %[[E_ADDR:.*]] = alloca ptr, align 8
+// OGCG:   %[[CALL:.*]] = invoke noundef i32 @_Z8divisionv()
+// OGCG:           to label %[[INVOKE_NORMAL:.*]] unwind label %[[INVOKE_UNWIND:.*]]
+// OGCG: [[INVOKE_NORMAL]]:
+// OGCG:   br label %[[TRY_CONT:.*]]
+// OGCG: [[INVOKE_UNWIND]]:
+// OGCG:   %[[LANDING_PAD:.*]] = landingpad { ptr, i32 }
+// OGCG:           catch ptr @_ZTIi
+// OGCG:   %[[EXCEPTION:.*]] = extractvalue { ptr, i32 } %[[LANDING_PAD]], 0
+// OGCG:   store ptr %1, ptr %[[EXCEPTION_ADDR]], align 8
+// OGCG:   %[[EH_TYPE_ID:.*]] = extractvalue { ptr, i32 } %[[LANDING_PAD]], 1
+// OGCG:   store i32 %[[EH_TYPE_ID]], ptr %[[EH_TYPE_ID_ADDR]], align 4
+// OGCG:   br label %[[CATCH_DISPATCH:.*]]
+// OGCG: [[CATCH_DISPATCH]]:
+// OGCG:   %[[TMP_EH_TYPE_ID:.*]] = load i32, ptr %[[EH_TYPE_ID_ADDR]], align 4
+// OGCG:   %[[EH_TYPE_ID:.*]] = call i32 @llvm.eh.typeid.for.p0(ptr @_ZTIi)
+// OGCG:   %[[TYPE_ID_EQ:.*]] = icmp eq i32 %[[TMP_EH_TYPE_ID]], %[[EH_TYPE_ID]]
+// OGCG:   br i1 %[[TYPE_ID_EQ]], label %[[CATCH_EXCEPTION:.*]], label %[[EH_RESUME:.*]]
+// OGCG: [[CATCH_EXCEPTION]]:
+// OGCG:   %[[TMP_EXCEPTION:.*]] = load ptr, ptr %[[EXCEPTION_ADDR]], align 8
+// OGCG:   %[[BEGIN_CATCH:.*]] = call ptr @__cxa_begin_catch(ptr %[[TMP_EXCEPTION]])
+// OGCG:   store ptr %[[BEGIN_CATCH]], ptr %[[E_ADDR]], align 8
+// OGCG:   call void @__cxa_end_catch()
+// OGCG:   br label %[[TRY_CONT]]
+// OGCG: [[TRY_CONT]]:
+// OGCG:   ret void
+// OGCG: [[EH_RESUME]]:
+// OGCG:   %[[TMP_EXCEPTION:.*]] = load ptr, ptr %[[EXCEPTION_ADDR]], align 8
+// OGCG:   %[[TMP_EH_TYPE_ID:.*]] = load i32, ptr %[[EH_TYPE_ID_ADDR]], align 4
+// OGCG:   %[[TMP_EXCEPTION_INFO:.*]] = insertvalue { ptr, i32 } poison, ptr %[[TMP_EXCEPTION]], 0
+// OGCG:   %[[EXCEPTION_INFO:.*]] = insertvalue { ptr, i32 } %[[TMP_EXCEPTION_INFO]], i32 %[[TMP_EH_TYPE_ID]], 1
+// OGCG:   resume { ptr, i32 } %[[EXCEPTION_INFO]]
+
 void call_function_inside_try_catch_with_complex_exception_type() {
   try {
     division();

``````````

</details>


https://github.com/llvm/llvm-project/pull/184442