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| author | Richard Smith <richard-llvm@metafoo.co.uk> | 2019-06-20 20:44:45 +0000 |
|---|---|---|
| committer | Richard Smith <richard-llvm@metafoo.co.uk> | 2019-06-20 20:44:45 +0000 |
| commit | 78b239ea67cf248a5c04031050c32f707f127a9d (patch) | |
| tree | 23150096a3e3d50ec9a6285ddf6d170b6a61ac20 /clang/test/CodeGenCXX/tail-padding.cpp | |
| parent | 60ca31a7ddabb46c9ea3762949629433c5eb4c8c (diff) | |
| download | bcm5719-llvm-78b239ea67cf248a5c04031050c32f707f127a9d.tar.gz bcm5719-llvm-78b239ea67cf248a5c04031050c32f707f127a9d.zip | |
P0840R2: support for [[no_unique_address]] attribute
Summary:
Add support for the C++2a [[no_unique_address]] attribute for targets using the Itanium C++ ABI.
This depends on D63371.
Reviewers: rjmccall, aaron.ballman
Subscribers: dschuff, aheejin, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63451
llvm-svn: 363976
Diffstat (limited to 'clang/test/CodeGenCXX/tail-padding.cpp')
| -rw-r--r-- | clang/test/CodeGenCXX/tail-padding.cpp | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/clang/test/CodeGenCXX/tail-padding.cpp b/clang/test/CodeGenCXX/tail-padding.cpp index b8b9e4ccf9a..afb97a00da7 100644 --- a/clang/test/CodeGenCXX/tail-padding.cpp +++ b/clang/test/CodeGenCXX/tail-padding.cpp @@ -32,3 +32,47 @@ namespace InitWithinNVSize { // CHECK: store i32 {{.*}} @_ZTVN16InitWithinNVSize1CE // CHECK: store i8 } + +namespace NoUniqueAddr { + struct A { char c; A(const A&); }; + struct B { int n; char c[3]; ~B(); }; + struct C : virtual A { B b; }; + struct D : virtual A { [[no_unique_address]] B b; }; + struct E : virtual A { [[no_unique_address]] B b; char x; }; + static_assert(sizeof(C) == sizeof(void*) + 8 + alignof(void*)); + static_assert(sizeof(D) == sizeof(void*) + 8); + static_assert(sizeof(E) == sizeof(void*) + 8 + alignof(void*)); + + // CHECK: define {{.*}} @_ZN12NoUniqueAddr1CC1EOS0_ + // CHECK: call void @_ZN12NoUniqueAddr1AC2ERKS0_( + // CHECK: store i32 {{.*}} @_ZTVN12NoUniqueAddr1CE + // Copy the full size of B. + // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}, i8* {{.*}}, i64 8, i1 false) + C f(C c) { return c; } + + // CHECK: define {{.*}} @_ZN12NoUniqueAddr1DC1EOS0_ + // CHECK: call void @_ZN12NoUniqueAddr1AC2ERKS0_( + // CHECK: store i32 {{.*}} @_ZTVN12NoUniqueAddr1DE + // Copy just the data size of B, to avoid overwriting the A base class. + // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}, i8* {{.*}}, i64 7, i1 false) + D f(D d) { return d; } + + // CHECK: define {{.*}} @_ZN12NoUniqueAddr1EC1EOS0_ + // CHECK: call void @_ZN12NoUniqueAddr1AC2ERKS0_( + // CHECK: store i32 {{.*}} @_ZTVN12NoUniqueAddr1EE + // We can copy the full size of B here. (As it happens, we fold the copy of 'x' into + // this memcpy, so we're copying 8 bytes either way.) + // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}, i8* {{.*}}, i64 8, i1 false) + E f(E e) { return e; } + + struct F : virtual A { + F(const F &o) : A(o), b(o.b) {} + [[no_unique_address]] B b; + }; + + // CHECK: define {{.*}} @_ZN12NoUniqueAddr1FC1ERKS0_ + // CHECK: call void @_ZN12NoUniqueAddr1AC2ERKS0_( + // CHECK: store i32 {{.*}} @_ZTVN12NoUniqueAddr1FE + // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}, i8* {{.*}}, i64 7, i1 false) + F f(F x) { return x; } +} |
