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bac5d0e9a1
When Swift imports C structs, it synthesizes an initializer that takes no arguments and zero-initializes the C struct. When C++ interop is enabled, Clang treats all C structs as if they were C++ structs. This means that some of the C structs will get a default constructor implicitly generated by Clang. This implicit default constructor will not zero-initialize trivial fields of the struct. This is a common source of confusion and subtle bugs for developers who try to enable C++ interop in existing projects that use C interop and rely on zero-initialization of C structs. rdar://115909532
53 lines
2.9 KiB
Swift
53 lines
2.9 KiB
Swift
// Target-specific tests for C++ constructor call code generation.
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// RUN: %swift -module-name MySwift -target x86_64-unknown-windows-msvc %target-swift-flags -dump-clang-diagnostics -I %S/Inputs -enable-experimental-cxx-interop -emit-ir %s -parse-stdlib -parse-as-library -disable-legacy-type-info | %FileCheck %s -check-prefix=MICROSOFT_X64
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// REQUIRES: OS=windows-msvc
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// REQUIRES: CPU=x86_64
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import Constructors
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import TypeClassification
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public func createHasVirtualBase() -> HasVirtualBase {
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// MICROSOFT_X64: define dllexport swiftcc void @"$s7MySwift20createHasVirtualBaseSo0{{bcD0VyF|deF0VyF}}"(ptr noalias sret({{.*}}) [[V0:%.*]])
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// MICROSOFT_X64-NOT: define
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// Note `this` return type and implicit "most derived" argument.
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// MICROSOFT_X64: [[V1:%.*]] = alloca %{{.*}}, align 8
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// MICROSOFT_X64: call ptr @"??0HasVirtualBase@@QEAA@UArgType@@@Z"(ptr [[V1]], i32 %{{[0-9]+}}, i32 1)
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// MICROSOFT_X64: call ptr @"??0HasVirtualBase@@QEAA@UArgType@@@Z"(ptr [[V0]], i32 %{{[0-9]+}}, i32 1)
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let _ : HasVirtualBase = HasVirtualBase(ArgType())
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return HasVirtualBase(ArgType())
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}
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public func createImplicitDefaultConstructor() -> ImplicitDefaultConstructor {
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// MICROSOFT_X64: define dllexport swiftcc i32 @"$s7MySwift32createImplicitDefaultConstructorSo0{{bcD0VyF|deF0VyF}}"()
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// MICROSOFT_X64-NOT: define
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// Note `this` return type but no implicit "most derived" argument.
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// MICROSOFT_X64: call void @llvm.memset.p0.i64
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// MICROSOFT_X64: call ptr @"??0ImplicitDefaultConstructor@@QEAA@XZ"(ptr %{{[0-9]+}})
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return ImplicitDefaultConstructor()
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}
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public func createStructWithSubobjectCopyConstructorAndValue() {
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// MICROSOFT_X64-LABEL: define dllexport swiftcc void @"$s7MySwift48createStructWithSubobjectCopyConstructorAndValueyyF"()
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// MICROSOFT_X64: [[MEMBER:%.*]] = alloca %TSo33StructWithCopyConstructorAndValueV
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// MICROSOFT_X64: [[OBJ:%.*]] = alloca %TSo42StructWithSubobjectCopyConstructorAndValueV
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// MICROSOFT_X64: [[TMP:%.*]] = alloca %TSo33StructWithCopyConstructorAndValueV
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// MICROSOFT_X64: call ptr @"??0StructWithCopyConstructorAndValue@@QEAA@XZ"(ptr [[MEMBER]])
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// MICROSOFT_X64: call ptr @"??0StructWithCopyConstructorAndValue@@QEAA@AEBU0@@Z"(ptr [[TMP]], ptr [[MEMBER]])
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// MICROSOFT_X64: ret void
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let member = StructWithCopyConstructorAndValue()
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let obj = StructWithSubobjectCopyConstructorAndValue(member: member)
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}
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public func createTemplatedConstructor() {
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// MICROSOFT_X64-LABEL: define dllexport swiftcc void @"$s7MySwift26createTemplatedConstructoryyF"()
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// MICROSOFT_X64: [[OBJ:%.*]] = alloca %TSo20TemplatedConstructorV
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// MICROSOFT_X64: [[IVAL:%.*]] = load i32, ptr
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// MICROSOFT_X64: call ptr @"??$?0UArgType@@@TemplatedConstructor@@QEAA@UArgType@@@Z"(ptr [[OBJ]], i32 [[IVAL]])
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// MICROSOFT_X64: ret void
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// MICROSOFT_X64-LABEL: define {{.*}}ptr @"??$?0UArgType@@@TemplatedConstructor@@QEAA@UArgType@@@Z"(ptr {{.*}}, i32 {{.*}})
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let templated = TemplatedConstructor(ArgType())
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}
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