From 6054d5aa7b35a4d2274fd999acfb499d9f796789 Mon Sep 17 00:00:00 2001 From: John McCall Date: Tue, 7 May 2013 05:20:46 +0000 Subject: [PATCH] Weaken an assertion in memcpyization to account for unnamed bitfields. Unnamed bitfields won't have an explicit copy operation in the AST, which breaks the strong form of the invariant. rdar://13816940 llvm-svn: 181289 --- clang/lib/CodeGen/CGClass.cpp | 8 +++- .../CodeGenCXX/copy-constructor-synthesis.cpp | 41 +++++++++++++++++++ 2 files changed, 47 insertions(+), 2 deletions(-) diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp index 3fd075701d03..e4180a0d72da 100644 --- a/clang/lib/CodeGen/CGClass.cpp +++ b/clang/lib/CodeGen/CGClass.cpp @@ -859,8 +859,12 @@ namespace { } void addNextField(FieldDecl *F) { - assert(F->getFieldIndex() == LastAddedFieldIndex + 1 && - "Cannot aggregate non-contiguous fields."); + // For the most part, the following invariant will hold: + // F->getFieldIndex() == LastAddedFieldIndex + 1 + // The one exception is that Sema won't add a copy-initializer for an + // unnamed bitfield, which will show up here as a gap in the sequence. + assert(F->getFieldIndex() >= LastAddedFieldIndex + 1 && + "Cannot aggregate fields out of order."); LastAddedFieldIndex = F->getFieldIndex(); // The 'first' and 'last' fields are chosen by offset, rather than field diff --git a/clang/test/CodeGenCXX/copy-constructor-synthesis.cpp b/clang/test/CodeGenCXX/copy-constructor-synthesis.cpp index 68f680574b75..f6c38219517c 100644 --- a/clang/test/CodeGenCXX/copy-constructor-synthesis.cpp +++ b/clang/test/CodeGenCXX/copy-constructor-synthesis.cpp @@ -136,6 +136,32 @@ void f(B b1) { B b2 = b1; } +// CHECK: define linkonce_odr [[A:%.*]]* @_ZN12rdar138169401AaSERKS0_( +// CHECK: [[THIS:%.*]] = load [[A]]** +// CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [[A]]* [[THIS]], i32 0, i32 1 +// CHECK-NEXT: [[T1:%.*]] = bitcast [2 x i8]* [[T0]] to i16* +// CHECK-NEXT: [[OTHER:%.*]] = load [[A]]** +// CHECK-NEXT: [[T2:%.*]] = getelementptr inbounds [[A]]* [[OTHER]], i32 0, i32 1 +// CHECK-NEXT: [[T3:%.*]] = bitcast [2 x i8]* [[T2]] to i16* +// CHECK-NEXT: [[T4:%.*]] = bitcast i16* [[T1]] to i8* +// CHECK-NEXT: [[T5:%.*]] = bitcast i16* [[T3]] to i8* +// CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[T4]], i8* [[T5]], i64 8, i32 8, i1 false) +// CHECK-NEXT: ret [[A]]* [[THIS]] + +// CHECK: define linkonce_odr void @_ZN12rdar138169401AC2ERKS0_( +// CHECK: [[THIS:%.*]] = load [[A]]** +// CHECK-NEXT: [[T0:%.*]] = bitcast [[A]]* [[THIS]] to i8*** +// CHECK-NEXT: store i8** getelementptr inbounds ([4 x i8*]* @_ZTVN12rdar138169401AE, i64 0, i64 2), i8*** [[T0]] +// CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [[A]]* [[THIS]], i32 0, i32 1 +// CHECK-NEXT: [[T1:%.*]] = bitcast [2 x i8]* [[T0]] to i16* +// CHECK-NEXT: [[OTHER:%.*]] = load [[A]]** +// CHECK-NEXT: [[T2:%.*]] = getelementptr inbounds [[A]]* [[OTHER]], i32 0, i32 1 +// CHECK-NEXT: [[T3:%.*]] = bitcast [2 x i8]* [[T2]] to i16* +// CHECK-NEXT: [[T4:%.*]] = bitcast i16* [[T1]] to i8* +// CHECK-NEXT: [[T5:%.*]] = bitcast i16* [[T3]] to i8* +// CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[T4]], i8* [[T5]], i64 8, i32 8, i1 false) +// CHECK-NEXT: ret void + // CHECK: define linkonce_odr void @_ZN6PR66281BC2ERKS0_(%"struct.PR6628::B"* %this, %"struct.PR6628::B"*) unnamed_addr // CHECK: call void @_ZN6PR66281TC1Ev // CHECK: call void @_ZN6PR66281TC1Ev @@ -154,3 +180,18 @@ void f(B b1) { // CHECK: call void @_ZN6PR66281TD1Ev } +// rdar://13816940 +// Test above because things get weirdly re-ordered. +namespace rdar13816940 { + struct A { + virtual ~A(); + unsigned short a : 1; + unsigned short : 15; + unsigned other; + }; + + void test(A &a) { + A x = a; // force copy constructor into existence + x = a; // also force the copy assignment operator + } +}