llvm-6502/unittests/Support/AlignOfTest.cpp

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//=== - llvm/unittest/Support/AlignOfTest.cpp - Alignment utility tests ----===//
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifdef _MSC_VER
// Disable warnings about alignment-based structure padding.
// This must be above the includes to suppress warnings in included templates.
#pragma warning(disable:4324)
#endif
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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#include "llvm/Support/AlignOf.h"
#include "llvm/Support/Compiler.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
// Disable warnings about questionable type definitions.
// We're testing that even questionable types work with the alignment utilities.
#ifdef _MSC_VER
#pragma warning(disable:4584)
#endif
// Suppress direct base '{anonymous}::S1' inaccessible in '{anonymous}::D9'
// due to ambiguity warning.
#ifdef __clang__
#pragma clang diagnostic ignored "-Wunknown-pragmas"
#pragma clang diagnostic ignored "-Winaccessible-base"
#elif ((__GNUC__ * 100) + __GNUC_MINOR__) >= 402
// Pragma based warning suppression was introduced in GGC 4.2. Additionally
// this warning is "enabled by default". The warning still appears if -Wall is
// suppressed. Apparently GCC suppresses it when -w is specifed, which is odd.
#pragma GCC diagnostic warning "-w"
#endif
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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// Define some fixed alignment types to use in these tests.
struct LLVM_ALIGNAS(1) A1 {};
struct LLVM_ALIGNAS(2) A2 {};
struct LLVM_ALIGNAS(4) A4 {};
struct LLVM_ALIGNAS(8) A8 {};
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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struct S1 {};
struct S2 { char a; };
struct S3 { int x; };
struct S4 { double y; };
struct S5 { A1 a1; A2 a2; A4 a4; A8 a8; };
struct S6 { double f(); };
struct D1 : S1 {};
struct D2 : S6 { float g(); };
struct D3 : S2 {};
struct D4 : S2 { int x; };
struct D5 : S3 { char c; };
struct D6 : S2, S3 {};
struct D7 : S1, S3 {};
struct D8 : S1, D4, D5 { double x[2]; };
struct D9 : S1, D1 { S1 s1; };
struct V1 { virtual ~V1(); };
struct V2 { int x; virtual ~V2(); };
struct V3 : V1 {
~V3() override;
};
struct V4 : virtual V2 { int y;
~V4() override;
};
struct V5 : V4, V3 { double z;
~V5() override;
};
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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struct V6 : S1 { virtual ~V6(); };
struct V7 : virtual V2, virtual V6 {
~V7() override;
};
struct V8 : V5, virtual V6, V7 { double zz;
~V8() override;
};
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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double S6::f() { return 0.0; }
float D2::g() { return 0.0f; }
V1::~V1() {}
V2::~V2() {}
V3::~V3() {}
V4::~V4() {}
V5::~V5() {}
V6::~V6() {}
V7::~V7() {}
V8::~V8() {}
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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// Ensure alignment is a compile-time constant.
char LLVM_ATTRIBUTE_UNUSED test_arr1
[AlignOf<char>::Alignment > 0]
[AlignOf<short>::Alignment > 0]
[AlignOf<int>::Alignment > 0]
[AlignOf<long>::Alignment > 0]
[AlignOf<long long>::Alignment > 0]
[AlignOf<float>::Alignment > 0]
[AlignOf<double>::Alignment > 0]
[AlignOf<long double>::Alignment > 0]
[AlignOf<void *>::Alignment > 0]
[AlignOf<int *>::Alignment > 0]
[AlignOf<double (*)(double)>::Alignment > 0]
[AlignOf<double (S6::*)()>::Alignment > 0];
char LLVM_ATTRIBUTE_UNUSED test_arr2
[AlignOf<A1>::Alignment > 0]
[AlignOf<A2>::Alignment > 0]
[AlignOf<A4>::Alignment > 0]
[AlignOf<A8>::Alignment > 0];
char LLVM_ATTRIBUTE_UNUSED test_arr3
[AlignOf<S1>::Alignment > 0]
[AlignOf<S2>::Alignment > 0]
[AlignOf<S3>::Alignment > 0]
[AlignOf<S4>::Alignment > 0]
[AlignOf<S5>::Alignment > 0]
[AlignOf<S6>::Alignment > 0];
char LLVM_ATTRIBUTE_UNUSED test_arr4
[AlignOf<D1>::Alignment > 0]
[AlignOf<D2>::Alignment > 0]
[AlignOf<D3>::Alignment > 0]
[AlignOf<D4>::Alignment > 0]
[AlignOf<D5>::Alignment > 0]
[AlignOf<D6>::Alignment > 0]
[AlignOf<D7>::Alignment > 0]
[AlignOf<D8>::Alignment > 0]
[AlignOf<D9>::Alignment > 0];
char LLVM_ATTRIBUTE_UNUSED test_arr5
[AlignOf<V1>::Alignment > 0]
[AlignOf<V2>::Alignment > 0]
[AlignOf<V3>::Alignment > 0]
[AlignOf<V4>::Alignment > 0]
[AlignOf<V5>::Alignment > 0]
[AlignOf<V6>::Alignment > 0]
[AlignOf<V7>::Alignment > 0]
[AlignOf<V8>::Alignment > 0];
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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TEST(AlignOfTest, BasicAlignmentInvariants) {
EXPECT_LE(1u, alignOf<A1>());
EXPECT_LE(2u, alignOf<A2>());
EXPECT_LE(4u, alignOf<A4>());
EXPECT_LE(8u, alignOf<A8>());
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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EXPECT_EQ(1u, alignOf<char>());
EXPECT_LE(alignOf<char>(), alignOf<short>());
EXPECT_LE(alignOf<short>(), alignOf<int>());
EXPECT_LE(alignOf<int>(), alignOf<long>());
EXPECT_LE(alignOf<long>(), alignOf<long long>());
EXPECT_LE(alignOf<char>(), alignOf<float>());
EXPECT_LE(alignOf<float>(), alignOf<double>());
EXPECT_LE(alignOf<char>(), alignOf<long double>());
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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EXPECT_LE(alignOf<char>(), alignOf<void *>());
EXPECT_EQ(alignOf<void *>(), alignOf<int *>());
EXPECT_LE(alignOf<char>(), alignOf<S1>());
EXPECT_LE(alignOf<S1>(), alignOf<S2>());
EXPECT_LE(alignOf<S1>(), alignOf<S3>());
EXPECT_LE(alignOf<S1>(), alignOf<S4>());
EXPECT_LE(alignOf<S1>(), alignOf<S5>());
EXPECT_LE(alignOf<S1>(), alignOf<S6>());
EXPECT_LE(alignOf<S1>(), alignOf<D1>());
EXPECT_LE(alignOf<S1>(), alignOf<D2>());
EXPECT_LE(alignOf<S1>(), alignOf<D3>());
EXPECT_LE(alignOf<S1>(), alignOf<D4>());
EXPECT_LE(alignOf<S1>(), alignOf<D5>());
EXPECT_LE(alignOf<S1>(), alignOf<D6>());
EXPECT_LE(alignOf<S1>(), alignOf<D7>());
EXPECT_LE(alignOf<S1>(), alignOf<D8>());
EXPECT_LE(alignOf<S1>(), alignOf<D9>());
EXPECT_LE(alignOf<S1>(), alignOf<V1>());
EXPECT_LE(alignOf<V1>(), alignOf<V2>());
EXPECT_LE(alignOf<V1>(), alignOf<V3>());
EXPECT_LE(alignOf<V1>(), alignOf<V4>());
EXPECT_LE(alignOf<V1>(), alignOf<V5>());
EXPECT_LE(alignOf<V1>(), alignOf<V6>());
EXPECT_LE(alignOf<V1>(), alignOf<V7>());
EXPECT_LE(alignOf<V1>(), alignOf<V8>());
}
TEST(AlignOfTest, BasicAlignedArray) {
EXPECT_LE(1u, alignOf<AlignedCharArrayUnion<A1> >());
EXPECT_LE(2u, alignOf<AlignedCharArrayUnion<A2> >());
EXPECT_LE(4u, alignOf<AlignedCharArrayUnion<A4> >());
EXPECT_LE(8u, alignOf<AlignedCharArrayUnion<A8> >());
EXPECT_LE(1u, sizeof(AlignedCharArrayUnion<A1>));
EXPECT_LE(2u, sizeof(AlignedCharArrayUnion<A2>));
EXPECT_LE(4u, sizeof(AlignedCharArrayUnion<A4>));
EXPECT_LE(8u, sizeof(AlignedCharArrayUnion<A8>));
EXPECT_EQ(1u, (alignOf<AlignedCharArrayUnion<A1> >()));
EXPECT_EQ(2u, (alignOf<AlignedCharArrayUnion<A1, A2> >()));
EXPECT_EQ(4u, (alignOf<AlignedCharArrayUnion<A1, A2, A4> >()));
EXPECT_EQ(8u, (alignOf<AlignedCharArrayUnion<A1, A2, A4, A8> >()));
EXPECT_EQ(1u, sizeof(AlignedCharArrayUnion<A1>));
EXPECT_EQ(2u, sizeof(AlignedCharArrayUnion<A1, A2>));
EXPECT_EQ(4u, sizeof(AlignedCharArrayUnion<A1, A2, A4>));
EXPECT_EQ(8u, sizeof(AlignedCharArrayUnion<A1, A2, A4, A8>));
EXPECT_EQ(1u, (alignOf<AlignedCharArrayUnion<A1[1]> >()));
EXPECT_EQ(2u, (alignOf<AlignedCharArrayUnion<A1[2], A2[1]> >()));
EXPECT_EQ(4u, (alignOf<AlignedCharArrayUnion<A1[42], A2[55],
A4[13]> >()));
EXPECT_EQ(8u, (alignOf<AlignedCharArrayUnion<A1[2], A2[1],
A4, A8> >()));
EXPECT_EQ(1u, sizeof(AlignedCharArrayUnion<A1[1]>));
EXPECT_EQ(2u, sizeof(AlignedCharArrayUnion<A1[2], A2[1]>));
EXPECT_EQ(4u, sizeof(AlignedCharArrayUnion<A1[3], A2[2], A4>));
EXPECT_EQ(16u, sizeof(AlignedCharArrayUnion<A1, A2[3],
A4[3], A8>));
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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// For other tests we simply assert that the alignment of the union mathes
// that of the fundamental type and hope that we have any weird type
// productions that would trigger bugs.
EXPECT_EQ(alignOf<char>(), alignOf<AlignedCharArrayUnion<char> >());
EXPECT_EQ(alignOf<short>(), alignOf<AlignedCharArrayUnion<short> >());
EXPECT_EQ(alignOf<int>(), alignOf<AlignedCharArrayUnion<int> >());
EXPECT_EQ(alignOf<long>(), alignOf<AlignedCharArrayUnion<long> >());
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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EXPECT_EQ(alignOf<long long>(),
alignOf<AlignedCharArrayUnion<long long> >());
EXPECT_EQ(alignOf<float>(), alignOf<AlignedCharArrayUnion<float> >());
EXPECT_EQ(alignOf<double>(), alignOf<AlignedCharArrayUnion<double> >());
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
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EXPECT_EQ(alignOf<long double>(),
alignOf<AlignedCharArrayUnion<long double> >());
EXPECT_EQ(alignOf<void *>(), alignOf<AlignedCharArrayUnion<void *> >());
EXPECT_EQ(alignOf<int *>(), alignOf<AlignedCharArrayUnion<int *> >());
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-16 08:52:57 +00:00
EXPECT_EQ(alignOf<double (*)(double)>(),
alignOf<AlignedCharArrayUnion<double (*)(double)> >());
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-16 08:52:57 +00:00
EXPECT_EQ(alignOf<double (S6::*)()>(),
alignOf<AlignedCharArrayUnion<double (S6::*)()> >());
EXPECT_EQ(alignOf<S1>(), alignOf<AlignedCharArrayUnion<S1> >());
EXPECT_EQ(alignOf<S2>(), alignOf<AlignedCharArrayUnion<S2> >());
EXPECT_EQ(alignOf<S3>(), alignOf<AlignedCharArrayUnion<S3> >());
EXPECT_EQ(alignOf<S4>(), alignOf<AlignedCharArrayUnion<S4> >());
EXPECT_EQ(alignOf<S5>(), alignOf<AlignedCharArrayUnion<S5> >());
EXPECT_EQ(alignOf<S6>(), alignOf<AlignedCharArrayUnion<S6> >());
EXPECT_EQ(alignOf<D1>(), alignOf<AlignedCharArrayUnion<D1> >());
EXPECT_EQ(alignOf<D2>(), alignOf<AlignedCharArrayUnion<D2> >());
EXPECT_EQ(alignOf<D3>(), alignOf<AlignedCharArrayUnion<D3> >());
EXPECT_EQ(alignOf<D4>(), alignOf<AlignedCharArrayUnion<D4> >());
EXPECT_EQ(alignOf<D5>(), alignOf<AlignedCharArrayUnion<D5> >());
EXPECT_EQ(alignOf<D6>(), alignOf<AlignedCharArrayUnion<D6> >());
EXPECT_EQ(alignOf<D7>(), alignOf<AlignedCharArrayUnion<D7> >());
EXPECT_EQ(alignOf<D8>(), alignOf<AlignedCharArrayUnion<D8> >());
EXPECT_EQ(alignOf<D9>(), alignOf<AlignedCharArrayUnion<D9> >());
EXPECT_EQ(alignOf<V1>(), alignOf<AlignedCharArrayUnion<V1> >());
EXPECT_EQ(alignOf<V2>(), alignOf<AlignedCharArrayUnion<V2> >());
EXPECT_EQ(alignOf<V3>(), alignOf<AlignedCharArrayUnion<V3> >());
EXPECT_EQ(alignOf<V4>(), alignOf<AlignedCharArrayUnion<V4> >());
EXPECT_EQ(alignOf<V5>(), alignOf<AlignedCharArrayUnion<V5> >());
EXPECT_EQ(alignOf<V6>(), alignOf<AlignedCharArrayUnion<V6> >());
EXPECT_EQ(alignOf<V7>(), alignOf<AlignedCharArrayUnion<V7> >());
// Some versions of MSVC get this wrong somewhat disturbingly. The failure
// appears to be benign: alignOf<V8>() produces a preposterous value: 12
#ifndef _MSC_VER
EXPECT_EQ(alignOf<V8>(), alignOf<AlignedCharArrayUnion<V8> >());
#endif
EXPECT_EQ(sizeof(char), sizeof(AlignedCharArrayUnion<char>));
EXPECT_EQ(sizeof(char[1]), sizeof(AlignedCharArrayUnion<char[1]>));
EXPECT_EQ(sizeof(char[2]), sizeof(AlignedCharArrayUnion<char[2]>));
EXPECT_EQ(sizeof(char[3]), sizeof(AlignedCharArrayUnion<char[3]>));
EXPECT_EQ(sizeof(char[4]), sizeof(AlignedCharArrayUnion<char[4]>));
EXPECT_EQ(sizeof(char[5]), sizeof(AlignedCharArrayUnion<char[5]>));
EXPECT_EQ(sizeof(char[8]), sizeof(AlignedCharArrayUnion<char[8]>));
EXPECT_EQ(sizeof(char[13]), sizeof(AlignedCharArrayUnion<char[13]>));
EXPECT_EQ(sizeof(char[16]), sizeof(AlignedCharArrayUnion<char[16]>));
EXPECT_EQ(sizeof(char[21]), sizeof(AlignedCharArrayUnion<char[21]>));
EXPECT_EQ(sizeof(char[32]), sizeof(AlignedCharArrayUnion<char[32]>));
EXPECT_EQ(sizeof(short), sizeof(AlignedCharArrayUnion<short>));
EXPECT_EQ(sizeof(int), sizeof(AlignedCharArrayUnion<int>));
EXPECT_EQ(sizeof(long), sizeof(AlignedCharArrayUnion<long>));
EXPECT_EQ(sizeof(long long),
sizeof(AlignedCharArrayUnion<long long>));
EXPECT_EQ(sizeof(float), sizeof(AlignedCharArrayUnion<float>));
EXPECT_EQ(sizeof(double), sizeof(AlignedCharArrayUnion<double>));
EXPECT_EQ(sizeof(long double),
sizeof(AlignedCharArrayUnion<long double>));
EXPECT_EQ(sizeof(void *), sizeof(AlignedCharArrayUnion<void *>));
EXPECT_EQ(sizeof(int *), sizeof(AlignedCharArrayUnion<int *>));
EXPECT_EQ(sizeof(double (*)(double)),
sizeof(AlignedCharArrayUnion<double (*)(double)>));
EXPECT_EQ(sizeof(double (S6::*)()),
sizeof(AlignedCharArrayUnion<double (S6::*)()>));
EXPECT_EQ(sizeof(S1), sizeof(AlignedCharArrayUnion<S1>));
EXPECT_EQ(sizeof(S2), sizeof(AlignedCharArrayUnion<S2>));
EXPECT_EQ(sizeof(S3), sizeof(AlignedCharArrayUnion<S3>));
EXPECT_EQ(sizeof(S4), sizeof(AlignedCharArrayUnion<S4>));
EXPECT_EQ(sizeof(S5), sizeof(AlignedCharArrayUnion<S5>));
EXPECT_EQ(sizeof(S6), sizeof(AlignedCharArrayUnion<S6>));
EXPECT_EQ(sizeof(D1), sizeof(AlignedCharArrayUnion<D1>));
EXPECT_EQ(sizeof(D2), sizeof(AlignedCharArrayUnion<D2>));
EXPECT_EQ(sizeof(D3), sizeof(AlignedCharArrayUnion<D3>));
EXPECT_EQ(sizeof(D4), sizeof(AlignedCharArrayUnion<D4>));
EXPECT_EQ(sizeof(D5), sizeof(AlignedCharArrayUnion<D5>));
EXPECT_EQ(sizeof(D6), sizeof(AlignedCharArrayUnion<D6>));
EXPECT_EQ(sizeof(D7), sizeof(AlignedCharArrayUnion<D7>));
EXPECT_EQ(sizeof(D8), sizeof(AlignedCharArrayUnion<D8>));
EXPECT_EQ(sizeof(D9), sizeof(AlignedCharArrayUnion<D9>));
EXPECT_EQ(sizeof(D9[1]), sizeof(AlignedCharArrayUnion<D9[1]>));
EXPECT_EQ(sizeof(D9[2]), sizeof(AlignedCharArrayUnion<D9[2]>));
EXPECT_EQ(sizeof(D9[3]), sizeof(AlignedCharArrayUnion<D9[3]>));
EXPECT_EQ(sizeof(D9[4]), sizeof(AlignedCharArrayUnion<D9[4]>));
EXPECT_EQ(sizeof(D9[5]), sizeof(AlignedCharArrayUnion<D9[5]>));
EXPECT_EQ(sizeof(D9[8]), sizeof(AlignedCharArrayUnion<D9[8]>));
EXPECT_EQ(sizeof(D9[13]), sizeof(AlignedCharArrayUnion<D9[13]>));
EXPECT_EQ(sizeof(D9[16]), sizeof(AlignedCharArrayUnion<D9[16]>));
EXPECT_EQ(sizeof(D9[21]), sizeof(AlignedCharArrayUnion<D9[21]>));
EXPECT_EQ(sizeof(D9[32]), sizeof(AlignedCharArrayUnion<D9[32]>));
EXPECT_EQ(sizeof(V1), sizeof(AlignedCharArrayUnion<V1>));
EXPECT_EQ(sizeof(V2), sizeof(AlignedCharArrayUnion<V2>));
EXPECT_EQ(sizeof(V3), sizeof(AlignedCharArrayUnion<V3>));
EXPECT_EQ(sizeof(V4), sizeof(AlignedCharArrayUnion<V4>));
EXPECT_EQ(sizeof(V5), sizeof(AlignedCharArrayUnion<V5>));
EXPECT_EQ(sizeof(V6), sizeof(AlignedCharArrayUnion<V6>));
EXPECT_EQ(sizeof(V7), sizeof(AlignedCharArrayUnion<V7>));
// Some versions of MSVC also get this wrong. The failure again appears to be
// benign: sizeof(V8) is only 52 bytes, but our array reserves 56.
#ifndef _MSC_VER
EXPECT_EQ(sizeof(V8), sizeof(AlignedCharArrayUnion<V8>));
#endif
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-16 08:52:57 +00:00
EXPECT_EQ(1u, (alignOf<AlignedCharArray<1, 1> >()));
EXPECT_EQ(2u, (alignOf<AlignedCharArray<2, 1> >()));
EXPECT_EQ(4u, (alignOf<AlignedCharArray<4, 1> >()));
EXPECT_EQ(8u, (alignOf<AlignedCharArray<8, 1> >()));
EXPECT_EQ(16u, (alignOf<AlignedCharArray<16, 1> >()));
EXPECT_EQ(1u, sizeof(AlignedCharArray<1, 1>));
EXPECT_EQ(7u, sizeof(AlignedCharArray<1, 7>));
EXPECT_EQ(2u, sizeof(AlignedCharArray<2, 2>));
EXPECT_EQ(16u, sizeof(AlignedCharArray<2, 16>));
}
Add support to the alignment support header for conjuring a character array of a suitable size and alignment for any of a number of different types to be stored into the character array. The mechanisms for producing an explicitly aligned type are fairly complex because this operation is poorly supported on all compilers. We've spent a fairly significant amount of time experimenting with different implementations inside of Google, and the one using explicitly expanded templates has been the most robust. Credit goes to Nick Lewycky for writing the first 20 versions or so of this logic we had inside of Google. I based this on the only one to actually survive. In case anyone is worried, yes we are both explicitly re-contributing and re-licensing it for LLVM. =] Once the issues with actually specifying the alignment are finished, it turns out that most compilers don't in turn align anything the way they are instructed. Testing of this logic against both Clang and GCC indicate that the alignment constraints are largely ignored by both compilers! I've come up with and used a work-around by wrapping each alignment-hinted type directly in a struct, and using that struct to align the character array through a union. This elaborate hackery is terrifying, but I've included testing that caught a terrifying number of bugs in every other technique I've tried. All of this in order to implement a poor C++98 programmers emulation of C++11 unrestricted unions in classes such as SmallDenseMap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158597 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-16 08:52:57 +00:00
}