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[CIR][CIRGen] Support a defined pure virtual destructor #825

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bcardosolopes merged 1 commit into from
Sep 11, 2024
Merged

[CIR][CIRGen] Support a defined pure virtual destructor #825

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9 changes: 8 additions & 1 deletion clang/lib/CIR/CodeGen/CIRGenClass.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1109,7 +1109,14 @@ void CIRGenFunction::buildDestructorBody(FunctionArgList &Args) {
// in fact emit references to them from other compilations, so emit them
// as functions containing a trap instruction.
if (DtorType != Dtor_Base && Dtor->getParent()->isAbstract()) {
llvm_unreachable("NYI");
SourceLocation Loc =
Dtor->hasBody() ? Dtor->getBody()->getBeginLoc() : Dtor->getLocation();
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@bcardosolopes bcardosolopes Sep 11, 2024

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It'd make slightly more sense if the trap is has the getEndLoc instead.

builder.create<mlir::cir::TrapOp>(getLoc(Loc));
// The corresponding clang/CodeGen logic clears the insertion point here,
// but MLIR's builder requires a valid insertion point, so we create a dummy
// block (since the trap is a block terminator).
builder.createBlock(builder.getBlock()->getParent());
return;
}

Stmt *Body = Dtor->getBody();
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58 changes: 58 additions & 0 deletions clang/test/CIR/CodeGen/defined-pure-virtual-func.cpp
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@@ -0,0 +1,58 @@
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir
// RUN: FileCheck --input-file=%t.cir %s

// Pure virtual functions are allowed to be defined, but the vtable should still
// point to __cxa_pure_virtual instead of the definition. For destructors, the
// base object destructor (which is not included in the vtable) should be
// defined as usual. The complete object destructors and deleting destructors
// should contain a trap, and the vtable entries for them should point to
// __cxa_pure_virtual.
class C {
C();
virtual ~C() = 0;
virtual void pure() = 0;
};

C::C() = default;
C::~C() = default;
void C::pure() {}

// CHECK: @_ZTV1C = #cir.vtable<{#cir.const_array<[#cir.ptr<null> : !cir.ptr<!u8i>, #cir.global_view<@_ZTI1C> : !cir.ptr<!u8i>
// complete object destructor (D1)
// CHECK-SAME: #cir.global_view<@__cxa_pure_virtual> : !cir.ptr<!u8i>,
// deleting destructor (D0)
// CHECK-SAME: #cir.global_view<@__cxa_pure_virtual> : !cir.ptr<!u8i>,
// C::pure
// CHECK-SAME: #cir.global_view<@__cxa_pure_virtual> : !cir.ptr<!u8i>]>

// The base object destructor should be emitted as normal.
// CHECK-LABEL: cir.func @_ZN1CD2Ev(%arg0: !cir.ptr<!ty_C> loc({{[^)]+}})) {{.*}} {
// CHECK-NEXT: %0 = cir.alloca !cir.ptr<!ty_C>, !cir.ptr<!cir.ptr<!ty_C>>, ["this", init] {alignment = 8 : i64}
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@bcardosolopes bcardosolopes Sep 11, 2024

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In general, the tests should use regex for the SSA values, should make them a little more resistant to overall CIR changes.

// CHECK-NEXT: cir.store %arg0, %0 : !cir.ptr<!ty_C>, !cir.ptr<!cir.ptr<!ty_C>>
// CHECK-NEXT: %1 = cir.load %0 : !cir.ptr<!cir.ptr<!ty_C>>, !cir.ptr<!ty_C>
// CHECK-NEXT: cir.return
// CHECK-NEXT: }

// The complete object destructor should trap.
// CHECK-LABEL: cir.func @_ZN1CD1Ev(%arg0: !cir.ptr<!ty_C> loc({{[^)]+}})) {{.*}} {
// CHECK-NEXT: %0 = cir.alloca !cir.ptr<!ty_C>, !cir.ptr<!cir.ptr<!ty_C>>, ["this", init] {alignment = 8 : i64}
// CHECK-NEXT: cir.store %arg0, %0 : !cir.ptr<!ty_C>, !cir.ptr<!cir.ptr<!ty_C>>
// CHECK-NEXT: %1 = cir.load %0 : !cir.ptr<!cir.ptr<!ty_C>>, !cir.ptr<!ty_C>
// CHECK-NEXT: cir.trap
// CHECK-NEXT: }

// The deleting destructor should trap.
// CHECK-LABEL: cir.func @_ZN1CD0Ev(%arg0: !cir.ptr<!ty_C> loc({{[^)]+}})) {{.*}} {
// CHECK-NEXT: %0 = cir.alloca !cir.ptr<!ty_C>, !cir.ptr<!cir.ptr<!ty_C>>, ["this", init] {alignment = 8 : i64}
// CHECK-NEXT: cir.store %arg0, %0 : !cir.ptr<!ty_C>, !cir.ptr<!cir.ptr<!ty_C>>
// CHECK-NEXT: %1 = cir.load %0 : !cir.ptr<!cir.ptr<!ty_C>>, !cir.ptr<!ty_C>
// CHECK-NEXT: cir.trap
// CHECK-NEXT: }

// C::pure should be emitted as normal.
// CHECK-LABEL: cir.func @_ZN1C4pureEv(%arg0: !cir.ptr<!ty_C> loc({{[^)]+}})) {{.*}} {
// CHECK-NEXT: %0 = cir.alloca !cir.ptr<!ty_C>, !cir.ptr<!cir.ptr<!ty_C>>, ["this", init] {alignment = 8 : i64}
// CHECK-NEXT: cir.store %arg0, %0 : !cir.ptr<!ty_C>, !cir.ptr<!cir.ptr<!ty_C>>
// CHECK-NEXT: %1 = cir.load %0 : !cir.ptr<!cir.ptr<!ty_C>>, !cir.ptr<!ty_C>
// CHECK-NEXT: cir.return
// CHECK-NEXT: }