[clang] [CIR] Fix try_call replacement for indirect calls (PR #185095)
via cfe-commits
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Fri Mar 6 12:01:46 PST 2026
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang
Author: Andy Kaylor (andykaylor)
<details>
<summary>Changes</summary>
We had a bug in the FlattenCFG pass where if an indirect call occurred within a cleanup scope that required exception handling, the indirect callee was not being preserved in the cir.try_call. This fixes that.
---
Full diff: https://github.com/llvm/llvm-project/pull/185095.diff
4 Files Affected:
- (modified) clang/lib/CIR/Dialect/Transforms/FlattenCFG.cpp (+16-6)
- (added) clang/test/CIR/CodeGen/virtual-fn-calls-eh.cpp (+124)
- (modified) clang/test/CIR/CodeGen/virtual-function-calls.cpp (+47)
- (modified) clang/test/CIR/Transforms/flatten-try-op.cir (+49)
``````````diff
diff --git a/clang/lib/CIR/Dialect/Transforms/FlattenCFG.cpp b/clang/lib/CIR/Dialect/Transforms/FlattenCFG.cpp
index 0b778c1c3393a..15602c29a2be1 100644
--- a/clang/lib/CIR/Dialect/Transforms/FlattenCFG.cpp
+++ b/clang/lib/CIR/Dialect/Transforms/FlattenCFG.cpp
@@ -648,12 +648,22 @@ static void replaceCallWithTryCall(cir::CallOp callOp, mlir::Block *unwindDest,
// Build the try_call to replace the original call.
rewriter.setInsertionPoint(callOp);
- mlir::Type resType = callOp->getNumResults() > 0
- ? callOp->getResult(0).getType()
- : mlir::Type();
- auto tryCallOp =
- cir::TryCallOp::create(rewriter, loc, callOp.getCalleeAttr(), resType,
- normalDest, unwindDest, callOp.getArgOperands());
+ cir::TryCallOp tryCallOp;
+ if (callOp.isIndirect()) {
+ mlir::Value indTarget = callOp.getIndirectCall();
+ auto ptrTy = mlir::cast<cir::PointerType>(indTarget.getType());
+ auto resTy = mlir::cast<cir::FuncType>(ptrTy.getPointee());
+ tryCallOp =
+ cir::TryCallOp::create(rewriter, loc, indTarget, resTy, normalDest,
+ unwindDest, callOp.getArgOperands());
+ } else {
+ mlir::Type resType = callOp->getNumResults() > 0
+ ? callOp->getResult(0).getType()
+ : mlir::Type();
+ tryCallOp =
+ cir::TryCallOp::create(rewriter, loc, callOp.getCalleeAttr(), resType,
+ normalDest, unwindDest, callOp.getArgOperands());
+ }
// Replace uses of the call result with the try_call result.
if (callOp->getNumResults() > 0)
diff --git a/clang/test/CIR/CodeGen/virtual-fn-calls-eh.cpp b/clang/test/CIR/CodeGen/virtual-fn-calls-eh.cpp
new file mode 100644
index 0000000000000..b72e54de8005a
--- /dev/null
+++ b/clang/test/CIR/CodeGen/virtual-fn-calls-eh.cpp
@@ -0,0 +1,124 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -mconstructor-aliases -fcxx-exceptions -fexceptions -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+// RUN: cir-opt --cir-flatten-cfg %t.cir -o %t-flat.cir
+// RUN: FileCheck --input-file=%t-flat.cir %s --check-prefix=CIR-FLAT
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -mconstructor-aliases -fcxx-exceptions -fexceptions -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --input-file=%t-cir.ll %s -check-prefix=LLVM
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -mconstructor-aliases -fcxx-exceptions -fexceptions -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG
+
+struct B {
+ ~B();
+ virtual void f(char);
+};
+
+void call_virtual_fn_in_cleanup_scope() {
+ B b;
+ b.f('c');
+}
+
+// CIR: cir.func {{.*}} @_Z32call_virtual_fn_in_cleanup_scopev()
+// CIR: %[[B:.*]] = cir.alloca !rec_B, !cir.ptr<!rec_B>, ["b", init]
+// CIR: cir.call @_ZN1BC2Ev(%[[B]])
+// CIR: cir.cleanup.scope {
+// CIR: %[[C_LITERAL:.*]] = cir.const #cir.int<99> : !s8i
+// CIR: %[[VPTR_ADDR:.*]] = cir.vtable.get_vptr %[[B]] : !cir.ptr<!rec_B> -> !cir.ptr<!cir.vptr>
+// CIR: %[[VPTR:.*]] = cir.load{{.*}} %[[VPTR_ADDR]]
+// CIR: %[[FN_PTR_ADDR:.*]] = cir.vtable.get_virtual_fn_addr %[[VPTR]][0] : !cir.vptr -> !cir.ptr<!cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>>
+// CIR: %[[FN_PTR:.*]] = cir.load{{.*}} %[[FN_PTR_ADDR:.*]] : !cir.ptr<!cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>>, !cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>
+// CIR: cir.call %[[FN_PTR]](%[[B]], %[[C_LITERAL]]) : (!cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>, !cir.ptr<!rec_B> {{.*}}, !s8i {{.*}}) -> ()
+// CIR: cir.yield
+// CIR: } cleanup all {
+// CIR: cir.call @_ZN1BD1Ev(%[[B]]) nothrow : (!cir.ptr<!rec_B> {{.*}}) -> ()
+// CIR: cir.yield
+// CIR: }
+
+// CIR-FLAT: cir.func {{.*}} @_Z32call_virtual_fn_in_cleanup_scopev()
+// CIR-FLAT: %[[B:.*]] = cir.alloca !rec_B, !cir.ptr<!rec_B>, ["b", init]
+// CIR-FLAT: cir.call @_ZN1BC2Ev(%[[B]]) nothrow : (!cir.ptr<!rec_B> {{.*}}) -> ()
+// CIR-FLAT: cir.br ^[[CLEANUP_SCOPE:bb[0-9]+]]
+// CIR-FLAT: ^[[CLEANUP_SCOPE]]:
+// CIR-FLAT: %[[C_LITERAL:.*]] = cir.const #cir.int<99> : !s8i
+// CIR-FLAT: %[[VPTR_ADDR:.*]] = cir.vtable.get_vptr %[[B]] : !cir.ptr<!rec_B> -> !cir.ptr<!cir.vptr>
+// CIR-FLAT: %[[VPTR:.*]] = cir.load{{.*}} %[[VPTR_ADDR]]
+// CIR-FLAT: %[[FN_PTR_ADDR:.*]] = cir.vtable.get_virtual_fn_addr %[[VPTR]][0] : !cir.vptr -> !cir.ptr<!cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>>
+// CIR-FLAT: %[[FN_PTR:.*]] = cir.load{{.*}} %[[FN_PTR_ADDR:.*]] : !cir.ptr<!cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>>, !cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>
+// CIR-FLAT: cir.try_call %[[FN_PTR]](%[[B]], %[[C_LITERAL]]) ^[[NORMAL:bb[0-9]+]], ^[[UNWIND:bb[0-9]+]] : (!cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>, !cir.ptr<!rec_B>, !s8i) -> ()
+// CIR-FLAT: ^[[NORMAL]]: // pred: ^bb1
+// CIR-FLAT: cir.br ^[[NORMAL_CLEANUP:bb[0-9]+]]
+// CIR-FLAT: ^[[NORMAL_CLEANUP]]:
+// CIR-FLAT: cir.call @_ZN1BD1Ev(%[[B]]) nothrow : (!cir.ptr<!rec_B> {{.*}}) -> ()
+// CIR-FLAT: cir.br ^[[NORMAL_CONTINUE:bb[0-9]+]]
+// CIR-FLAT: ^[[NORMAL_CONTINUE]]:
+// CIR-FLAT: cir.br ^[[TRY_CONTINUE:bb[0-9]+]]
+// CIR-FLAT: ^[[UNWIND]]: // pred: ^bb1
+// CIR-FLAT: %[[EH_TOKEN:.*]] = cir.eh.initiate cleanup : !cir.eh_token
+// CIR-FLAT: cir.br ^[[EH_CLEANUP:bb[0-9]+]](%[[EH_TOKEN]] : !cir.eh_token)
+// CIR-FLAT: ^[[EH_CLEANUP]](%[[EH_TOKEN:.*]]: !cir.eh_token):
+// CIR-FLAT: %[[CT:.*]] = cir.begin_cleanup %[[EH_TOKEN]] : !cir.eh_token -> !cir.cleanup_token
+// CIR-FLAT: cir.call @_ZN1BD1Ev(%[[B]]) nothrow : (!cir.ptr<!rec_B> {{.*}}) -> ()
+// CIR-FLAT: cir.end_cleanup %[[CT]] : !cir.cleanup_token
+// CIR-FLAT: cir.resume %[[EH_TOKEN]] : !cir.eh_token
+// CIR-FLAT: ^[[TRY_CONTINUE]]:
+// CIR-FLAT: cir.return
+
+// LLVM: define {{.*}} void @_Z32call_virtual_fn_in_cleanup_scopev()
+// LLVM: %[[B:.*]] = alloca %struct.B
+// LLVM: call void @_ZN1BC2Ev(ptr {{.*}} %[[B]])
+// LLVM: br label %[[CLEANUP_SCOPE:.*]]
+// LLVM: [[CLEANUP_SCOPE]]:
+// LLVM: %[[B_VPTR:.*]] = load ptr, ptr %[[B]]
+// LLVM: %[[FN_PTR_ADDR:.*]] = getelementptr inbounds ptr, ptr %[[B_VPTR]], i32 0
+// LLVM: %[[FN_PTR:.*]] = load ptr, ptr %[[FN_PTR_ADDR]]
+// LLVM: invoke void %[[FN_PTR]](ptr %[[B]], i8 99)
+// LLVM: to label %[[NORMAL_CONTINUE:.*]] unwind label %[[UNWIND:.*]]
+// LLVM: [[NORMAL_CONTINUE]]
+// LLVM: br label %[[NORMAL_CLEANUP:.*]]
+// LLVM: [[NORMAL_CLEANUP]]:
+// LLVM: call void @_ZN1BD1Ev(ptr {{.*}} %[[B]])
+// LLVM: br label %[[EXIT_CLEANUP_SCOPE:.*]]
+// LLVM: [[EXIT_CLEANUP_SCOPE]]:
+// LLVM: br label %[[DONE:.*]]
+// LLVM: [[UNWIND]]:
+// LLVM: %[[EXN:.*]] = landingpad { ptr, i32 }
+// LLVM: cleanup
+// LLVM: %[[EXN_PTR:.*]] = extractvalue { ptr, i32 } %[[EXN]], 0
+// LLVM: %[[TYPEID:.*]] = extractvalue { ptr, i32 } %[[EXN]], 1
+// LLVM: br label %[[EH_CLEANUP:.*]]
+// LLVM: [[EH_CLEANUP]]:
+// LLVM: %[[EXN_PTR_PHI:.*]] = phi ptr [ %[[EXN_PTR]], %[[UNWIND]] ]
+// LLVM: %[[TYPEID_PHI:.*]] = phi i32 [ %[[TYPEID]], %[[UNWIND]] ]
+// LLVM: call void @_ZN1BD1Ev(ptr {{.*}} %[[B]])
+// LLVM: %[[EXN_INSERT:.*]] = insertvalue { ptr, i32 } poison, ptr %[[EXN_PTR_PHI]], 0
+// LLVM: %[[EXN_INSERT_2:.*]] = insertvalue { ptr, i32 } %[[EXN_INSERT]], i32 %[[TYPEID_PHI]], 1
+// LLVM: resume { ptr, i32 } %[[EXN_INSERT_2]]
+// LLVM: [[DONE]]:
+// LLVM: ret void
+
+// Note: OGCG devirtualizes the call. We don't do that yet in CIR.
+// OGCG: define {{.*}} void @_Z32call_virtual_fn_in_cleanup_scopev()
+// OGCG: %[[B:.*]] = alloca %struct.B, align 8
+// OGCG: %[[EXN_SLOT:.*]] = alloca ptr
+// OGCG: %[[EHSELECTOR_SLOT:.*]] = alloca i32
+// OGCG: call void @_ZN1BC2Ev(ptr {{.*}} %[[B]])
+// OGCG: invoke void @_ZN1B1fEc(ptr {{.*}} %[[B]], i8 {{.*}} 99)
+// OGCG: to label %[[INVOKE_CONT:.*]] unwind label %[[UNWIND:.*]]
+// OGCG: [[INVOKE_CONT]]:
+// OGCG: call void @_ZN1BD1Ev(ptr {{.*}} %[[B]])
+// OGCG: ret void
+// OGCG: [[UNWIND]]:
+// OGCG: %[[EXN:.*]] = landingpad { ptr, i32 }
+// OGCG: cleanup
+// OGCG: %[[EXN_PTR:.*]] = extractvalue { ptr, i32 } %[[EXN]], 0
+// OGCG: store ptr %[[EXN_PTR]], ptr %[[EXN_SLOT]]
+// OGCG: %[[TYPEID:.*]] = extractvalue { ptr, i32 } %[[EXN]], 1
+// OGCG: store i32 %[[TYPEID]], ptr %[[EHSELECTOR_SLOT]]
+// OGCG: call void @_ZN1BD1Ev(ptr {{.*}} %[[B]])
+// OGCG: br label %[[EH_RESUME:.*]]
+// OGCG: [[EH_RESUME]]:
+// OGCG: %[[EXN:.*]] = load ptr, ptr %[[EXN_SLOT]]
+// OGCG: %[[SEL:.*]] = load i32, ptr %[[EHSELECTOR_SLOT]]
+// OGCG: %[[LPAD_VAL:.*]] = insertvalue { ptr, i32 } poison, ptr %[[EXN]], 0
+// OGCG: %[[LPAD_VAL_1:.*]] = insertvalue { ptr, i32 } %[[LPAD_VAL]], i32 %[[SEL]], 1
+// OGCG: resume { ptr, i32 } %[[LPAD_VAL_1]]
+
\ No newline at end of file
diff --git a/clang/test/CIR/CodeGen/virtual-function-calls.cpp b/clang/test/CIR/CodeGen/virtual-function-calls.cpp
index 71f0af5bcb44e..b316aa2567b65 100644
--- a/clang/test/CIR/CodeGen/virtual-function-calls.cpp
+++ b/clang/test/CIR/CodeGen/virtual-function-calls.cpp
@@ -79,3 +79,50 @@ void f1(A *a) {
// OGCG: %[[FN_PTR_PTR:.*]] = getelementptr inbounds ptr, ptr %[[VPTR]], i64 0
// OGCG: %[[FN_PTR:.*]] = load ptr, ptr %[[FN_PTR_PTR]]
// OGCG: call void %[[FN_PTR]](ptr {{.*}} %[[A]], i8 {{.*}} 99)
+
+struct B {
+ ~B();
+ virtual void f(char);
+};
+
+void call_virtual_fn_in_cleanup_scope() {
+ B b;
+ b.f('c');
+}
+
+// CIR: cir.func {{.*}} @_Z32call_virtual_fn_in_cleanup_scopev()
+// CIR: %[[B:.*]] = cir.alloca !rec_B, !cir.ptr<!rec_B>, ["b", init]
+// CIR: cir.call @_ZN1BC2Ev(%[[B]])
+// CIR: cir.cleanup.scope {
+// CIR: %[[C_LITERAL:.*]] = cir.const #cir.int<99> : !s8i
+// CIR: %[[VPTR_ADDR:.*]] = cir.vtable.get_vptr %[[B]] : !cir.ptr<!rec_B> -> !cir.ptr<!cir.vptr>
+// CIR: %[[VPTR:.*]] = cir.load{{.*}} %[[VPTR_ADDR]]
+// CIR: %[[FN_PTR_ADDR:.*]] = cir.vtable.get_virtual_fn_addr %[[VPTR]][0] : !cir.vptr -> !cir.ptr<!cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>>
+// CIR: %[[FN_PTR:.*]] = cir.load{{.*}} %[[FN_PTR_ADDR:.*]] : !cir.ptr<!cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>>, !cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>
+// CIR: cir.call %[[FN_PTR]](%[[B]], %[[C_LITERAL]]) : (!cir.ptr<!cir.func<(!cir.ptr<!rec_B>, !s8i)>>, !cir.ptr<!rec_B> {{.*}}, !s8i {{.*}}) -> ()
+// CIR: cir.yield
+// CIR: } cleanup normal {
+// CIR: cir.call @_ZN1BD1Ev(%[[B]]) nothrow : (!cir.ptr<!rec_B> {{.*}}) -> ()
+// CIR: cir.yield
+// CIR: }
+
+// LLVM: define {{.*}} void @_Z32call_virtual_fn_in_cleanup_scopev()
+// LLVM: %[[B:.*]] = alloca %struct.B
+// LLVM: call void @_ZN1BC2Ev(ptr {{.*}} %[[B]])
+// LLVM: br label %[[CLEANUP_SCOPE:.*]]
+// LLVM: [[CLEANUP_SCOPE]]:
+// LLVM: %[[B_VPTR:.*]] = load ptr, ptr %[[B]]
+// LLVM: %[[FN_PTR_ADDR:.*]] = getelementptr inbounds ptr, ptr %[[B_VPTR]], i32 0
+// LLVM: %[[FN_PTR:.*]] = load ptr, ptr %[[FN_PTR_ADDR]]
+// LLVM: call void %[[FN_PTR]](ptr {{.*}} %[[B]], i8 noundef 99)
+// LLVM: br label %[[NORMAL_CLEANUP:.*]]
+// LLVM: [[NORMAL_CLEANUP]]:
+// LLVM: call void @_ZN1BD1Ev(ptr {{.*}} %[[B]])
+
+// Note: OGCG devirtualizes the call. We don't do that yet in CIR.
+// OGCG: define {{.*}} void @_Z32call_virtual_fn_in_cleanup_scopev()
+// OGCG: %[[B:.*]] = alloca %struct.B, align 8
+// OGCG: call void @_ZN1BC2Ev(ptr {{.*}} %[[B]])
+// OGCG: call void @_ZN1B1fEc(ptr {{.*}} %[[B]], i8 noundef signext 99)
+// OGCG: call void @_ZN1BD1Ev(ptr {{.*}} %[[B]])
+
\ No newline at end of file
diff --git a/clang/test/CIR/Transforms/flatten-try-op.cir b/clang/test/CIR/Transforms/flatten-try-op.cir
index fe4e8cdc98434..7270bd9d5e0fc 100644
--- a/clang/test/CIR/Transforms/flatten-try-op.cir
+++ b/clang/test/CIR/Transforms/flatten-try-op.cir
@@ -723,6 +723,55 @@ cir.func @test_try_multiple_typed_and_catch_all() {
// CHECK: ^[[RETURN]]:
// CHECK: cir.return
+// Test try-catch with an indirect (virtual) call in the try body.
+// The indirect call should become an indirect try_call.
+cir.func @test_try_indirect_call(%arg0 : !cir.ptr<!cir.func<(!cir.ptr<!rec_SomeClass>)>>,
+ %arg1 : !cir.ptr<!rec_SomeClass>) {
+ cir.scope {
+ cir.try {
+ cir.call %arg0(%arg1) : (!cir.ptr<!cir.func<(!cir.ptr<!rec_SomeClass>)>>, !cir.ptr<!rec_SomeClass>) -> ()
+ cir.yield
+ } catch all (%eh_token : !cir.eh_token) {
+ %catch_token, %exn_ptr = cir.begin_catch %eh_token : !cir.eh_token -> (!cir.catch_token, !cir.ptr<!cir.void>)
+ cir.end_catch %catch_token : !cir.catch_token
+ cir.yield
+ }
+ }
+ cir.return
+}
+
+// CHECK-LABEL: cir.func @test_try_indirect_call
+// CHECK-SAME: (%[[FPTR:.*]]: !cir.ptr<!cir.func<(!cir.ptr<!rec_SomeClass>)>>, %[[OBJ:.*]]: !cir.ptr<!rec_SomeClass>)
+// CHECK: cir.br ^[[SCOPE:bb[0-9]+]]
+//
+// CHECK: ^[[SCOPE]]:
+// CHECK: cir.br ^[[TRY_BODY:bb[0-9]+]]
+//
+// CHECK: ^[[TRY_BODY]]:
+// CHECK: cir.try_call %[[FPTR]](%[[OBJ]]) ^[[NORMAL:bb[0-9]+]], ^[[UNWIND:bb[0-9]+]] : (!cir.ptr<!cir.func<(!cir.ptr<!rec_SomeClass>)>>, !cir.ptr<!rec_SomeClass>) -> ()
+//
+// CHECK: ^[[NORMAL]]:
+// CHECK: cir.br ^[[CONTINUE:bb[0-9]+]]
+//
+// CHECK: ^[[UNWIND]]:
+// CHECK: %[[EH_TOK:.*]] = cir.eh.initiate : !cir.eh_token
+// CHECK: cir.br ^[[DISPATCH:bb[0-9]+]](%[[EH_TOK]] : !cir.eh_token)
+//
+// CHECK: ^[[DISPATCH]](%[[DISP_ET:.*]]: !cir.eh_token):
+// CHECK: cir.eh.dispatch %[[DISP_ET]] : !cir.eh_token [
+// CHECK: catch_all : ^[[CATCH_ALL:bb[0-9]+]]
+// CHECK: ]
+//
+// CHECK: ^[[CATCH_ALL]](%[[ET:.*]]: !cir.eh_token):
+// CHECK: %{{.*}}, %{{.*}} = cir.begin_catch %[[ET]] : !cir.eh_token -> (!cir.catch_token, !cir.ptr<!void>)
+// CHECK: cir.end_catch
+// CHECK: cir.br ^[[CONTINUE]]
+//
+// CHECK: ^[[CONTINUE]]:
+// CHECK: cir.br ^[[SCOPE_EXIT:bb[0-9]+]]
+// CHECK: ^[[SCOPE_EXIT]]:
+// CHECK: cir.return
+
cir.func private @mayThrow()
cir.func private @ctor(!cir.ptr<!rec_SomeClass>)
cir.func private @dtor(!cir.ptr<!rec_SomeClass>) attributes {nothrow}
``````````
</details>
https://github.com/llvm/llvm-project/pull/185095
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