[clang] [CIR] Add structured CatchParamOp (PR #165110)

[Amr Hesham via cfe-commits]

https://github.com/AmrDeveloper updated https://github.com/llvm/llvm-project/pull/165110

>From c5ce5c9985c401961ec518665d8fbc146c086993 Mon Sep 17 00:00:00 2001
From: Amr Hesham <amr96 at programmer.net>
Date: Fri, 5 Dec 2025 21:27:34 +0100
Subject: [PATCH 1/4] [CIR] Add structured CatchParamOp

---
 clang/include/clang/CIR/Dialect/IR/CIROps.td | 27 +++++++++++++++++
 clang/test/CIR/IR/catch-param.cir            | 32 ++++++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 clang/test/CIR/IR/catch-param.cir

diff --git a/clang/include/clang/CIR/Dialect/IR/CIROps.td b/clang/include/clang/CIR/Dialect/IR/CIROps.td
index caa047a51b689..f9a70166625a0 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIROps.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIROps.td
@@ -5183,6 +5183,33 @@ def CIR_TryOp : CIR_Op<"try",[
   let hasLLVMLowering = false;
 }
 
+//===----------------------------------------------------------------------===//
+// CatchParamOp
+//===----------------------------------------------------------------------===//
+
+def CIR_CatchParamOp : CIR_Op<"catch_param", [HasParent<"cir::TryOp">]> {
+  let summary = "Represents catch clause formal parameter";
+  let description = [{
+    The `cir.catch_param` operate in the catch regions of `cir.try`.
+
+    This operation is used only before the CFG flatterning pass.
+
+    Example:
+
+    ```mlir
+    %exception = cir.catch_param -> !cir.ptr<!void>
+    ```
+  }];
+
+  let results = (outs Optional<CIR_AnyType>:$param);
+  let assemblyFormat = [{
+    (`:` qualified(type($param))^)?
+    attr-dict
+  }];
+
+  let hasLLVMLowering = false;
+}
+
 //===----------------------------------------------------------------------===//
 // Exception related: EhInflightOp
 //===----------------------------------------------------------------------===//
diff --git a/clang/test/CIR/IR/catch-param.cir b/clang/test/CIR/IR/catch-param.cir
new file mode 100644
index 0000000000000..a16e8ec43c91b
--- /dev/null
+++ b/clang/test/CIR/IR/catch-param.cir
@@ -0,0 +1,32 @@
+// RUN: cir-opt %s --verify-roundtrip | FileCheck %s  
+
+!s32i = !cir.int<s, 32>
+!void = !cir.void
+
+module {
+
+cir.func @catch_param_inside_catch() {
+  cir.scope {
+    cir.try {
+      cir.yield
+    } catch all {
+      cir.catch_param : !cir.ptr<!void>
+      cir.yield
+    }
+  }
+  cir.return
+}
+
+// CHECK: cir.func @catch_param_inside_catch() {
+// CHECK:   cir.scope {
+// CHECK:     cir.try {
+// CHECK:       cir.yield
+// CHECK:     } catch all {
+// CHECK:       cir.catch_param : !cir.ptr<!void> 
+// CHECK:       cir.yield
+// CHECK:     }
+// CHECK:   }
+// CHECK:   cir.return
+// CHECK: }
+
+}

>From d5add3e20d97dd60c140a36f332b6f1912bd6ba9 Mon Sep 17 00:00:00 2001
From: Amr Hesham <amr96 at programmer.net>
Date: Fri, 5 Dec 2025 21:32:42 +0100
Subject: [PATCH 2/4] Update op example to match the current format

---
 clang/include/clang/CIR/Dialect/IR/CIROps.td | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/include/clang/CIR/Dialect/IR/CIROps.td b/clang/include/clang/CIR/Dialect/IR/CIROps.td
index f9a70166625a0..cd0248d60eec7 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIROps.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIROps.td
@@ -5197,7 +5197,7 @@ def CIR_CatchParamOp : CIR_Op<"catch_param", [HasParent<"cir::TryOp">]> {
     Example:
 
     ```mlir
-    %exception = cir.catch_param -> !cir.ptr<!void>
+    %exception = cir.catch_param : !cir.ptr<!void>
     ```
   }];
 

>From 3013ead0a1754da3d7be207338bb1f9641bdb186 Mon Sep 17 00:00:00 2001
From: Amr Hesham <amr96 at programmer.net>
Date: Fri, 5 Dec 2025 21:52:01 +0100
Subject: [PATCH 3/4] Update Op description

---
 clang/include/clang/CIR/Dialect/IR/CIROps.td | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/clang/include/clang/CIR/Dialect/IR/CIROps.td b/clang/include/clang/CIR/Dialect/IR/CIROps.td
index cd0248d60eec7..0ee0fe4dacfcf 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIROps.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIROps.td
@@ -5188,9 +5188,10 @@ def CIR_TryOp : CIR_Op<"try",[
 //===----------------------------------------------------------------------===//
 
 def CIR_CatchParamOp : CIR_Op<"catch_param", [HasParent<"cir::TryOp">]> {
-  let summary = "Represents catch clause formal parameter";
+  let summary = "Represents the catch clause formal parameter";
   let description = [{
-    The `cir.catch_param` operate in the catch regions of `cir.try`.
+    The `cir.catch_param` used to retrieves the exception object inside
+    the handler regions of `cir.try`.
 
     This operation is used only before the CFG flatterning pass.
 

>From df40edbc37ce872480148f93fb07828e263e7646 Mon Sep 17 00:00:00 2001
From: Amr Hesham <amr96 at programmer.net>
Date: Sat, 6 Dec 2025 12:28:12 +0100
Subject: [PATCH 4/4] Address code review comments

---
 clang/include/clang/CIR/Dialect/IR/CIROps.td | 2 +-
 clang/test/CIR/IR/catch-param.cir            | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/clang/include/clang/CIR/Dialect/IR/CIROps.td b/clang/include/clang/CIR/Dialect/IR/CIROps.td
index 0ee0fe4dacfcf..fcc7585cf81a5 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIROps.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIROps.td
@@ -5190,7 +5190,7 @@ def CIR_TryOp : CIR_Op<"try",[
 def CIR_CatchParamOp : CIR_Op<"catch_param", [HasParent<"cir::TryOp">]> {
   let summary = "Represents the catch clause formal parameter";
   let description = [{
-    The `cir.catch_param` used to retrieves the exception object inside
+    The `cir.catch_param` is used to retrieves the exception object inside
     the handler regions of `cir.try`.
 
     This operation is used only before the CFG flatterning pass.
diff --git a/clang/test/CIR/IR/catch-param.cir b/clang/test/CIR/IR/catch-param.cir
index a16e8ec43c91b..7b0f884fff11d 100644
--- a/clang/test/CIR/IR/catch-param.cir
+++ b/clang/test/CIR/IR/catch-param.cir
@@ -10,7 +10,7 @@ cir.func @catch_param_inside_catch() {
     cir.try {
       cir.yield
     } catch all {
-      cir.catch_param : !cir.ptr<!void>
+      %exception = cir.catch_param : !cir.ptr<!void>
       cir.yield
     }
   }
@@ -22,7 +22,7 @@ cir.func @catch_param_inside_catch() {
 // CHECK:     cir.try {
 // CHECK:       cir.yield
 // CHECK:     } catch all {
-// CHECK:       cir.catch_param : !cir.ptr<!void> 
+// CHECK:       %[[EXCEPTION:.*]] = cir.catch_param : !cir.ptr<!void> 
 // CHECK:       cir.yield
 // CHECK:     }
 // CHECK:   }