P0035R4: add predefined __STDCPP_DEFAULT_NEW_ALIGNMENT__ macro. By default, we

assume that ::operator new provides no more alignment than is necessary for any
primitive type, except when we're on a GNU OS, where glibc's malloc guarantees
to provide 64-bit alignment on 32-bit systems and 128-bit alignment on 64-bit
systems. This can be controlled by the command-line -fnew-alignment flag.

llvm-svn: 282974

diff --git a/clang/include/clang/Basic/DiagnosticFrontendKinds.td b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
index 06c2ceff5c7285803b45e663639769fa802c8efd..1267f8d09f58ad7c9b0bc14156c2a40074241470 100644 (file)
--- a/clang/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -114,6 +114,8 @@ def err_fe_no_pch_in_dir : Error<
     "no suitable precompiled header file found in directory '%0'">;
 def err_fe_action_not_available : Error<
     "action %0 not compiled in">;
+def err_fe_invalid_alignment : Error<
+    "invalid value '%1' in '%0'; alignment must be a power of 2">;
 
 def warn_fe_serialized_diag_merge_failure : Warning<
     "unable to merge a subprocess's serialized diagnostics">,

diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def
index b738f837178892feb8a2fbcd159ebc8db65087e1..aed11ffd39acd1f855cf650a61560e96a15b2746 100644 (file)
--- a/clang/include/clang/Basic/LangOptions.def
+++ b/clang/include/clang/Basic/LangOptions.def
@@ -195,7 +195,9 @@ LANGOPT(CUDAHostDeviceConstexpr, 1, 1, "treating unattributed constexpr function
 LANGOPT(CUDADeviceFlushDenormalsToZero, 1, 0, "flushing denormals to zero")
 LANGOPT(CUDADeviceApproxTranscendentals, 1, 0, "using approximate transcendental functions")
 
-LANGOPT(SizedDeallocation , 1, 0, "enable sized deallocation functions")
+LANGOPT(SizedDeallocation , 1, 0, "sized deallocation")
+LANGOPT(AlignedAllocation , 1, 0, "aligned allocation")
+LANGOPT(NewAlignOverride  , 32, 0, "maximum alignment guaranteed by '::operator new(size_t)'")
 LANGOPT(ConceptsTS , 1, 0, "enable C++ Extensions for Concepts")
 BENIGN_LANGOPT(ElideConstructors , 1, 1, "C++ copy constructor elision")
 BENIGN_LANGOPT(DumpRecordLayouts , 1, 0, "dumping the layout of IRgen'd records")

diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index 0d63989ab5f5a46f8da86fee2de7d8787a2355a6..dbdbff847347a09188517de64fffdb59a312c66f 100644 (file)
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -76,6 +76,7 @@ protected:
   unsigned short MaxVectorAlign;
   unsigned short MaxTLSAlign;
   unsigned short SimdDefaultAlign;
+  unsigned short NewAlign;
   std::unique_ptr<llvm::DataLayout> DataLayout;
   const char *MCountName;
   const llvm::fltSemantics *HalfFormat, *FloatFormat, *DoubleFormat,
@@ -353,6 +354,13 @@ public:
   /// unless its alignment is explicitly reduced via attributes.
   unsigned getMinGlobalAlign() const { return MinGlobalAlign; }
 
+  /// Return the largest alignment for which a suitably-sized allocation with
+  /// '::operator new(size_t)' is guaranteed to produce a correctly-aligned
+  /// pointer.
+  unsigned getNewAlign() const {
+    return NewAlign ? NewAlign : std::max(LongDoubleAlign, LongLongAlign);
+  }
+
   /// getWCharWidth/Align - Return the size of 'wchar_t' for this target, in
   /// bits.
   unsigned getWCharWidth() const { return getTypeWidth(WCharType); }

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 6090304a1b9b15ef7b57e11d58758edc7a1935f3..f9390a971dacc7178784fe8993273eb69b17f880 100644 (file)
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1046,6 +1046,17 @@ def fno_application_extension : Flag<["-"], "fno-application-extension">,
 def fsized_deallocation : Flag<["-"], "fsized-deallocation">, Flags<[CC1Option]>,
   HelpText<"Enable C++14 sized global deallocation functions">, Group<f_Group>;
 def fno_sized_deallocation: Flag<["-"], "fno-sized-deallocation">, Group<f_Group>;
+def faligned_allocation : Flag<["-"], "faligned-allocation">, Flags<[CC1Option]>,
+  HelpText<"Enable C++17 aligned allocation functions">, Group<f_Group>;
+def fno_aligned_allocation: Flag<["-"], "fno-aligned-allocation">,
+  Group<f_Group>, Flags<[CC1Option]>;
+def fnew_alignment_EQ : Joined<["-"], "fnew-alignment=">,
+  HelpText<"Specifies the largest alignment guaranteed by '::operator new(size_t)'">,
+  MetaVarName<"<align>">, Group<f_Group>, Flags<[CC1Option]>;
+def : Separate<["-"], "fnew-alignment">, Alias<fnew_alignment_EQ>;
+def : Flag<["-"], "faligned-new">, Alias<faligned_allocation>;
+def : Flag<["-"], "fno-aligned-new">, Alias<fno_aligned_allocation>;
+def faligned_new_EQ : Joined<["-"], "faligned-new=">;
 
 def fobjc_gc_only : Flag<["-"], "fobjc-gc-only">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Use GC exclusively for Objective-C related memory management">;

diff --git a/clang/lib/Basic/TargetInfo.cpp b/clang/lib/Basic/TargetInfo.cpp
index d455fa3956dd9934cbb1f96f5a0a3ee357eef72a..19cab14cbf40e0f9742407e8c274dcd182820499 100644 (file)
--- a/clang/lib/Basic/TargetInfo.cpp
+++ b/clang/lib/Basic/TargetInfo.cpp
@@ -39,6 +39,13 @@ TargetInfo::TargetInfo(const llvm::Triple &T) : TargetOpts(), Triple(T) {
   SuitableAlign = 64;
   DefaultAlignForAttributeAligned = 128;
   MinGlobalAlign = 0;
+  // From the glibc documentation, on GNU systems, malloc guarantees 16-byte
+  // alignment on 64-bit systems and 8-byte alignment on 32-bit systems. See
+  // https://www.gnu.org/software/libc/manual/html_node/Malloc-Examples.html
+  if (T.isGNUEnvironment())
+    NewAlign = Triple.isArch64Bit() ? 128 : Triple.isArch32Bit() ? 64 : 0;
+  else
+    NewAlign = 0; // Infer from basic type alignment.
   HalfWidth = 16;
   HalfAlign = 16;
   FloatWidth = 32;
@@ -320,6 +327,9 @@ void TargetInfo::adjust(const LangOptions &Opts) {
     FloatFormat = &llvm::APFloat::IEEEsingle;
     LongDoubleFormat = &llvm::APFloat::IEEEquad;
   }
+
+  if (Opts.NewAlignOverride)
+    NewAlign = Opts.NewAlignOverride * getCharWidth();
 }
 
 bool TargetInfo::initFeatureMap(

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 8e30ba1713b7f0e93ced9f419a6c047da44f2d18..f4710fa54935dced98254fd81a85b714e4ca53cc 100644 (file)
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -1768,6 +1768,7 @@ public:
     LongLongWidth = HostTarget->getLongLongWidth();
     LongLongAlign = HostTarget->getLongLongAlign();
     MinGlobalAlign = HostTarget->getMinGlobalAlign();
+    NewAlign = HostTarget->getNewAlign();
     DefaultAlignForAttributeAligned =
         HostTarget->getDefaultAlignForAttributeAligned();
     SizeType = HostTarget->getSizeType();

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 543d95804f615e87a517d92985c4e38d3e8e4331..dfd4ce73cddb27f93b1d8c4cdbe952ca5948a66d 100644 (file)
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -5821,6 +5821,24 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                    options::OPT_fno_sized_deallocation, false))
     CmdArgs.push_back("-fsized-deallocation");
 
+  // -faligned-allocation is on by default in C++17 onwards and otherwise off
+  // by default.
+  if (Arg *A = Args.getLastArg(options::OPT_faligned_allocation,
+                               options::OPT_fno_aligned_allocation,
+                               options::OPT_faligned_new_EQ)) {
+    if (A->getOption().matches(options::OPT_fno_aligned_allocation))
+      CmdArgs.push_back("-fno-aligned-allocation");
+    else
+      CmdArgs.push_back("-faligned-allocation");
+  }
+
+  // The default new alignment can be specified using a dedicated option or via
+  // a GCC-compatible option that also turns on aligned allocation.
+  if (Arg *A = Args.getLastArg(options::OPT_fnew_alignment_EQ,
+                               options::OPT_faligned_new_EQ))
+    CmdArgs.push_back(
+        Args.MakeArgString(Twine("-fnew-alignment=") + A->getValue()));
+
   // -fconstant-cfstrings is default, and may be subject to argument translation
   // on Darwin.
   if (!Args.hasFlag(options::OPT_fconstant_cfstrings,

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 6b2df349f8b0bd8fe070cae6b38dc9f22f6e3b7d..3406c324645e37a3d93556bde20a6362d7f349e9 100644 (file)
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1625,6 +1625,8 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
   Opts.GNUKeywords = Opts.GNUMode;
   Opts.CXXOperatorNames = Opts.CPlusPlus;
 
+  Opts.AlignedAllocation = Opts.CPlusPlus1z;
+
   Opts.DollarIdents = !Opts.AsmPreprocessor;
 }
 
@@ -1937,6 +1939,17 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
     getAllNoBuiltinFuncValues(Args, Opts.NoBuiltinFuncs);
   Opts.NoMathBuiltin = Args.hasArg(OPT_fno_math_builtin);
   Opts.SizedDeallocation = Args.hasArg(OPT_fsized_deallocation);
+  Opts.AlignedAllocation =
+      Args.hasFlag(OPT_faligned_allocation, OPT_fno_aligned_allocation,
+                   Opts.AlignedAllocation);
+  Opts.NewAlignOverride =
+      getLastArgIntValue(Args, OPT_fnew_alignment_EQ, 0, Diags);
+  if (Opts.NewAlignOverride && !llvm::isPowerOf2_32(Opts.NewAlignOverride)) {
+    Arg *A = Args.getLastArg(OPT_fnew_alignment_EQ);
+    Diags.Report(diag::err_fe_invalid_alignment) << A->getAsString(Args)
+                                                 << A->getValue();
+    Opts.NewAlignOverride = 0;
+  }
   Opts.ConceptsTS = Args.hasArg(OPT_fconcepts_ts);
   Opts.HeinousExtensions = Args.hasArg(OPT_fheinous_gnu_extensions);
   Opts.AccessControl = !Args.hasArg(OPT_fno_access_control);

diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 7d15e4cd589c632c11544f390be75ea642fd21d9..d7dccb1340b29fa9eb3cd197405ac7781d5582d8 100644 (file)
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -392,6 +392,15 @@ static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
     //   C++ translation unit.
     else
       Builder.defineMacro("__cplusplus", "199711L");
+
+    // C++1z [cpp.predefined]p1:
+    //   An integer literal of type std::size_t whose value is the alignment
+    //   guaranteed by a call to operator new(std::size_t)
+    //
+    // We provide this in all language modes, since it seems generally useful.
+    Builder.defineMacro("__STDCPP_DEFAULT_NEW_ALIGNMENT__",
+                        Twine(TI.getNewAlign() / TI.getCharWidth()) +
+                            TI.getTypeConstantSuffix(TI.getSizeType()));
   }
 
   // In C11 these are environment macros. In C++11 they are only defined

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index fc55661febc2bf395287e92080c7cfd691f861d2..be1a597c07e4c33a357c0eac045380e77bee1154 100644 (file)
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -2340,7 +2340,7 @@ void Sema::DeclareGlobalNewDelete() {
                                         nullptr);
     getStdBadAlloc()->setImplicit(true);
   }
-  if (!StdAlignValT && getLangOpts().CPlusPlus1z) {
+  if (!StdAlignValT && getLangOpts().AlignedAllocation) {
     // The "std::align_val_t" enum class has not yet been declared, so build it
     // implicitly.
     auto *AlignValT = EnumDecl::Create(
@@ -2365,7 +2365,7 @@ void Sema::DeclareGlobalNewDelete() {
     // Create up to four variants of the function (sized/aligned).
     bool HasSizedVariant = getLangOpts().SizedDeallocation &&
                            (Kind == OO_Delete || Kind == OO_Array_Delete);
-    bool HasAlignedVariant = getLangOpts().CPlusPlus1z;
+    bool HasAlignedVariant = getLangOpts().AlignedAllocation;
 
     int NumSizeVariants = (HasSizedVariant ? 2 : 1);
     int NumAlignVariants = (HasAlignedVariant ? 2 : 1);

diff --git a/clang/test/CXX/cpp/cpp.predefined/p1.cpp b/clang/test/CXX/cpp/cpp.predefined/p1.cpp
new file mode 100644 (file)
index 0000000..c0dcbd5
--- /dev/null
+++ b/clang/test/CXX/cpp/cpp.predefined/p1.cpp
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -std=c++1z %s -verify -triple x86_64-linux-gnu -DALIGN=16
+// RUN: %clang_cc1 -std=c++1z %s -verify -fnew-alignment=2 -DALIGN=2
+// RUN: %clang_cc1 -std=c++1z %s -verify -fnew-alignment=256 -DALIGN=256
+
+// expected-no-diagnostics
+
+#if ALIGN != __STDCPP_DEFAULT_NEW_ALIGNMENT__
+#error wrong value for __STDCPP_DEFAULT_NEW_ALIGNMENT__
+#endif

diff --git a/clang/test/Preprocessor/init.c b/clang/test/Preprocessor/init.c
index 16342332b84702874d5a899e1decbe80c1ab65e0..c541faa7ccd0e1a7665f489537467eea60dc8d2c 100644 (file)
--- a/clang/test/Preprocessor/init.c
+++ b/clang/test/Preprocessor/init.c
@@ -247,6 +247,7 @@
 
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=aarch64-none-none < /dev/null | FileCheck -match-full-lines -check-prefix AARCH64 %s
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=arm64-none-none < /dev/null | FileCheck -match-full-lines -check-prefix AARCH64 %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=arm64-none-none < /dev/null | FileCheck -match-full-lines -check-prefix AARCH64 -check-prefix AARCH64-CXX %s
 //
 // AARCH64:#define _LP64 1
 // AARCH64-NOT:#define __AARCH64EB__ 1
@@ -393,6 +394,7 @@
 // AARCH64:#define __SIZE_MAX__ 18446744073709551615UL
 // AARCH64:#define __SIZE_TYPE__ long unsigned int
 // AARCH64:#define __SIZE_WIDTH__ 64
+// AARCH64-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16UL
 // AARCH64:#define __UINT16_C_SUFFIX__
 // AARCH64:#define __UINT16_MAX__ 65535
 // AARCH64:#define __UINT16_TYPE__ unsigned short
@@ -1206,6 +1208,7 @@
 // AARCH64-DARWIN: #define __aarch64__ 1
 
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=arm-none-none < /dev/null | FileCheck -match-full-lines -check-prefix ARM %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=arm-none-none < /dev/null | FileCheck -match-full-lines -check-prefix ARM -check-prefix ARM-CXX %s
 //
 // ARM-NOT:#define _LP64
 // ARM:#define __APCS_32__ 1
@@ -1351,6 +1354,7 @@
 // ARM:#define __SIZE_MAX__ 4294967295U
 // ARM:#define __SIZE_TYPE__ unsigned int
 // ARM:#define __SIZE_WIDTH__ 32
+// ARM-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 8U
 // ARM:#define __UINT16_C_SUFFIX__
 // ARM:#define __UINT16_MAX__ 65535
 // ARM:#define __UINT16_TYPE__ unsigned short
@@ -2431,6 +2435,7 @@
 // I386:#define i386 1
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=i386-pc-linux-gnu -target-cpu pentium4 < /dev/null | FileCheck -match-full-lines -check-prefix I386-LINUX %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=i386-pc-linux-gnu -target-cpu pentium4 < /dev/null | FileCheck -match-full-lines -check-prefix I386-LINUX -check-prefix I386-LINUX-CXX %s
 //
 // I386-LINUX-NOT:#define _LP64
 // I386-LINUX:#define __BIGGEST_ALIGNMENT__ 16
@@ -2572,6 +2577,7 @@
 // I386-LINUX:#define __SIZE_MAX__ 4294967295U
 // I386-LINUX:#define __SIZE_TYPE__ unsigned int
 // I386-LINUX:#define __SIZE_WIDTH__ 32
+// I386-LINUX-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 8U
 // I386-LINUX:#define __UINT16_C_SUFFIX__
 // I386-LINUX:#define __UINT16_MAX__ 65535
 // I386-LINUX:#define __UINT16_TYPE__ unsigned short
@@ -2618,6 +2624,7 @@
 // I386-LINUX:#define i386 1
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=i386-netbsd < /dev/null | FileCheck -match-full-lines -check-prefix I386-NETBSD %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=i386-netbsd < /dev/null | FileCheck -match-full-lines -check-prefix I386-NETBSD -check-prefix I386-NETBSD-CXX %s
 //
 // I386-NETBSD-NOT:#define _LP64
 // I386-NETBSD:#define __BIGGEST_ALIGNMENT__ 16
@@ -2759,6 +2766,7 @@
 // I386-NETBSD:#define __SIZE_MAX__ 4294967295U
 // I386-NETBSD:#define __SIZE_TYPE__ unsigned int
 // I386-NETBSD:#define __SIZE_WIDTH__ 32
+// I386-NETBSD-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 4U
 // I386-NETBSD:#define __UINT16_C_SUFFIX__
 // I386-NETBSD:#define __UINT16_MAX__ 65535
 // I386-NETBSD:#define __UINT16_TYPE__ unsigned short
@@ -2818,7 +2826,8 @@
 // I386-DECLSPEC: #define __declspec{{.*}}
 
 //
-// RUN: %clang_cc1 -E -dM -ffreestanding -triple=mips-none-none < /dev/null | FileCheck -match-full-lines -check-prefix MIPS32BE %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -triple=mips-none-none < /dev/null | FileCheck -match-full-lines -check-prefix MIPS32BE -check-prefix MIPS32BE-C %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=mips-none-none < /dev/null | FileCheck -match-full-lines -check-prefix MIPS32BE -check-prefix MIPS32BE-CXX %s
 //
 // MIPS32BE:#define MIPSEB 1
 // MIPS32BE:#define _ABIO32 1
@@ -2973,8 +2982,9 @@
 // MIPS32BE:#define __SIZE_MAX__ 4294967295U
 // MIPS32BE:#define __SIZE_TYPE__ unsigned int
 // MIPS32BE:#define __SIZE_WIDTH__ 32
+// MIPS32BE-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 8U
 // MIPS32BE:#define __STDC_HOSTED__ 0
-// MIPS32BE:#define __STDC_VERSION__ 201112L
+// MIPS32BE-C:#define __STDC_VERSION__ 201112L
 // MIPS32BE:#define __STDC__ 1
 // MIPS32BE:#define __UINT16_C_SUFFIX__
 // MIPS32BE:#define __UINT16_MAX__ 65535
@@ -3235,7 +3245,10 @@
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding \
 // RUN:            -triple=mips64-none-none -target-abi n32 < /dev/null \
-// RUN:   | FileCheck -match-full-lines -check-prefix MIPSN32BE %s
+// RUN:   | FileCheck -match-full-lines -check-prefix MIPSN32BE -check-prefix MIPSN32BE-C %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding \
+// RUN:            -triple=mips64-none-none -target-abi n32 < /dev/null \
+// RUN:   | FileCheck -match-full-lines -check-prefix MIPSN32BE -check-prefix MIPSN32BE-CXX %s
 //
 // MIPSN32BE: #define MIPSEB 1
 // MIPSN32BE: #define _ABIN32 2
@@ -3304,7 +3317,7 @@
 // MIPSN32BE: #define __GCC_ATOMIC_WCHAR_T_LOCK_FREE 2
 // MIPSN32BE: #define __GNUC_MINOR__ 2
 // MIPSN32BE: #define __GNUC_PATCHLEVEL__ 1
-// MIPSN32BE: #define __GNUC_STDC_INLINE__ 1
+// MIPSN32BE-C: #define __GNUC_STDC_INLINE__ 1
 // MIPSN32BE: #define __GNUC__ 4
 // MIPSN32BE: #define __GXX_ABI_VERSION 1002
 // MIPSN32BE: #define __ILP32__ 1
@@ -3424,10 +3437,11 @@
 // MIPSN32BE: #define __SIZE_MAX__ 4294967295U
 // MIPSN32BE: #define __SIZE_TYPE__ unsigned int
 // MIPSN32BE: #define __SIZE_WIDTH__ 32
+// MIPSN32BE-CXX: #define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16U
 // MIPSN32BE: #define __STDC_HOSTED__ 0
 // MIPSN32BE: #define __STDC_UTF_16__ 1
 // MIPSN32BE: #define __STDC_UTF_32__ 1
-// MIPSN32BE: #define __STDC_VERSION__ 201112L
+// MIPSN32BE-C: #define __STDC_VERSION__ 201112L
 // MIPSN32BE: #define __STDC__ 1
 // MIPSN32BE: #define __UINT16_C_SUFFIX__
 // MIPSN32BE: #define __UINT16_FMTX__ "hX"
@@ -3846,6 +3860,7 @@
 // MIPSN32EL: #define mips 1
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=mips64-none-none < /dev/null | FileCheck -match-full-lines -check-prefix MIPS64BE %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=mips64-none-none < /dev/null | FileCheck -match-full-lines -check-prefix MIPS64BE -check-prefix MIPS64BE-CXX %s
 //
 // MIPS64BE:#define MIPSEB 1
 // MIPS64BE:#define _ABI64 3
@@ -4001,6 +4016,7 @@
 // MIPS64BE:#define __SIZE_MAX__ 18446744073709551615UL
 // MIPS64BE:#define __SIZE_TYPE__ long unsigned int
 // MIPS64BE:#define __SIZE_WIDTH__ 64
+// MIPS64BE-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16UL
 // MIPS64BE:#define __UINT16_C_SUFFIX__
 // MIPS64BE:#define __UINT16_MAX__ 65535
 // MIPS64BE:#define __UINT16_TYPE__ unsigned short
@@ -4489,6 +4505,7 @@
 // MIPS-XXR6:#define __mips_nan2008 1
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=msp430-none-none < /dev/null | FileCheck -match-full-lines -check-prefix MSP430 %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=msp430-none-none < /dev/null | FileCheck -match-full-lines -check-prefix MSP430 -check-prefix MSP430-CXX %s
 //
 // MSP430:#define MSP430 1
 // MSP430-NOT:#define _LP64
@@ -4630,6 +4647,7 @@
 // MSP430:#define __SIZE_MAX__ 65535U
 // MSP430:#define __SIZE_TYPE__ unsigned int
 // MSP430:#define __SIZE_WIDTH__ 16
+// MSP430-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 8U
 // MSP430:#define __UINT16_C_SUFFIX__ U
 // MSP430:#define __UINT16_MAX__ 65535U
 // MSP430:#define __UINT16_TYPE__ unsigned short
@@ -4674,6 +4692,7 @@
 // MSP430:#define __clang__ 1
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=nvptx-none-none < /dev/null | FileCheck -match-full-lines -check-prefix NVPTX32 %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=nvptx-none-none < /dev/null | FileCheck -match-full-lines -check-prefix NVPTX32 -check-prefix NVPTX32-CXX %s
 //
 // NVPTX32-NOT:#define _LP64
 // NVPTX32:#define __BIGGEST_ALIGNMENT__ 8
@@ -4818,6 +4837,7 @@
 // NVPTX32:#define __SIZE_MAX__ 4294967295U
 // NVPTX32:#define __SIZE_TYPE__ unsigned int
 // NVPTX32:#define __SIZE_WIDTH__ 32
+// NVPTX32-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 8U
 // NVPTX32:#define __UINT16_C_SUFFIX__
 // NVPTX32:#define __UINT16_MAX__ 65535
 // NVPTX32:#define __UINT16_TYPE__ unsigned short
@@ -4861,6 +4881,7 @@
 // NVPTX32:#define __WINT_WIDTH__ 32
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=nvptx64-none-none < /dev/null | FileCheck -match-full-lines -check-prefix NVPTX64 %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=nvptx64-none-none < /dev/null | FileCheck -match-full-lines -check-prefix NVPTX64 -check-prefix NVPTX64-CXX %s
 //
 // NVPTX64:#define _LP64 1
 // NVPTX64:#define __BIGGEST_ALIGNMENT__ 8
@@ -5005,6 +5026,7 @@
 // NVPTX64:#define __SIZE_MAX__ 18446744073709551615UL
 // NVPTX64:#define __SIZE_TYPE__ long unsigned int
 // NVPTX64:#define __SIZE_WIDTH__ 64
+// NVPTX64-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 8UL
 // NVPTX64:#define __UINT16_C_SUFFIX__
 // NVPTX64:#define __UINT16_MAX__ 65535
 // NVPTX64:#define __UINT16_TYPE__ unsigned short
@@ -5048,6 +5070,7 @@
 // NVPTX64:#define __WINT_WIDTH__ 32
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=powerpc-none-none -target-cpu 603e < /dev/null | FileCheck -match-full-lines -check-prefix PPC603E %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=powerpc-none-none -target-cpu 603e < /dev/null | FileCheck -match-full-lines -check-prefix PPC603E-CXX %s
 //
 // PPC603E:#define _ARCH_603 1
 // PPC603E:#define _ARCH_603E 1
@@ -5197,6 +5220,7 @@
 // PPC603E:#define __SIZE_MAX__ 4294967295UL
 // PPC603E:#define __SIZE_TYPE__ long unsigned int
 // PPC603E:#define __SIZE_WIDTH__ 32
+// PPC603E-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16UL
 // PPC603E:#define __UINT16_C_SUFFIX__
 // PPC603E:#define __UINT16_MAX__ 65535
 // PPC603E:#define __UINT16_TYPE__ unsigned short
@@ -5242,6 +5266,7 @@
 // PPC603E:#define __ppc__ 1
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=powerpc64-none-none -target-cpu pwr7 -fno-signed-char < /dev/null | FileCheck -match-full-lines -check-prefix PPC64 %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=powerpc64-none-none -target-cpu pwr7 -fno-signed-char < /dev/null | FileCheck -match-full-lines -check-prefix PPC64 -check-prefix PPC64-CXX %s
 //
 // PPC64:#define _ARCH_PPC 1
 // PPC64:#define _ARCH_PPC64 1
@@ -5397,6 +5422,7 @@
 // PPC64:#define __SIZE_MAX__ 18446744073709551615UL
 // PPC64:#define __SIZE_TYPE__ long unsigned int
 // PPC64:#define __SIZE_WIDTH__ 64
+// PPC64-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16UL
 // PPC64:#define __UINT16_C_SUFFIX__
 // PPC64:#define __UINT16_MAX__ 65535
 // PPC64:#define __UINT16_TYPE__ unsigned short
@@ -6662,6 +6688,7 @@
 // AMDGPU:#define cl_khr_local_int32_extended_atomics 1
 
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=s390x-none-none -fno-signed-char < /dev/null | FileCheck -match-full-lines -check-prefix S390X %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=s390x-none-none -fno-signed-char < /dev/null | FileCheck -match-full-lines -check-prefix S390X -check-prefix S390X-CXX %s
 //
 // S390X:#define __BIGGEST_ALIGNMENT__ 8
 // S390X:#define __CHAR16_TYPE__ unsigned short
@@ -6798,6 +6825,7 @@
 // S390X:#define __SIZEOF_WINT_T__ 4
 // S390X:#define __SIZE_TYPE__ long unsigned int
 // S390X:#define __SIZE_WIDTH__ 64
+// S390X-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 8UL
 // S390X:#define __UINT16_C_SUFFIX__
 // S390X:#define __UINT16_MAX__ 65535
 // S390X:#define __UINT16_TYPE__ unsigned short
@@ -6846,6 +6874,8 @@
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-rtems-elf < /dev/null | FileCheck -match-full-lines -check-prefix SPARC -check-prefix SPARC-DEFAULT %s
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-none-netbsd < /dev/null | FileCheck -match-full-lines -check-prefix SPARC -check-prefix SPARC-NETOPENBSD %s
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-none-openbsd < /dev/null | FileCheck -match-full-lines -check-prefix SPARC -check-prefix SPARC-NETOPENBSD %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=sparc-none-none < /dev/null | FileCheck -match-full-lines -check-prefix SPARC -check-prefix SPARC-DEFAULT -check-prefix SPARC-DEFAULT-CXX %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=sparc-none-openbsd < /dev/null | FileCheck -match-full-lines -check-prefix SPARC -check-prefix SPARC-NETOPENBSD -check-prefix SPARC-NETOPENBSD-CXX %s
 //
 // SPARC-NOT:#define _LP64
 // SPARC:#define __BIGGEST_ALIGNMENT__ 8
@@ -6993,6 +7023,8 @@
 // SPARC-NETOPENBSD:#define __SIZE_MAX__ 4294967295UL
 // SPARC-NETOPENBSD:#define __SIZE_TYPE__ long unsigned int
 // SPARC:#define __SIZE_WIDTH__ 32
+// SPARC-DEFAULT-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 8U
+// SPARC-NETOPENBSD-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 8UL
 // SPARC:#define __UINT16_C_SUFFIX__
 // SPARC:#define __UINT16_MAX__ 65535
 // SPARC:#define __UINT16_TYPE__ unsigned short
@@ -7043,6 +7075,7 @@
 // SPARC:#define sparc 1
 
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=tce-none-none < /dev/null | FileCheck -match-full-lines -check-prefix TCE %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=tce-none-none < /dev/null | FileCheck -match-full-lines -check-prefix TCE -check-prefix TCE-CXX %s
 //
 // TCE-NOT:#define _LP64
 // TCE:#define __BIGGEST_ALIGNMENT__ 4
@@ -7169,6 +7202,7 @@
 // TCE:#define __SIZE_MAX__ 4294967295U
 // TCE:#define __SIZE_TYPE__ unsigned int
 // TCE:#define __SIZE_WIDTH__ 32
+// TCE-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 4U
 // TCE:#define __TCE_V1__ 1
 // TCE:#define __TCE__ 1
 // TCE:#define __UINT16_C_SUFFIX__
@@ -7210,6 +7244,7 @@
 // TCE:#define tce 1
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=x86_64-none-none < /dev/null | FileCheck -match-full-lines -check-prefix X86_64 %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=x86_64-none-none < /dev/null | FileCheck -match-full-lines -check-prefix X86_64 -check-prefix X86_64-CXX %s
 //
 // X86_64:#define _LP64 1
 // X86_64-NOT:#define _LP32 1
@@ -7358,6 +7393,7 @@
 // X86_64:#define __SSE2__ 1
 // X86_64:#define __SSE_MATH__ 1
 // X86_64:#define __SSE__ 1
+// X86_64-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16UL
 // X86_64:#define __UINT16_C_SUFFIX__
 // X86_64:#define __UINT16_MAX__ 65535
 // X86_64:#define __UINT16_TYPE__ unsigned short
@@ -7412,6 +7448,7 @@
 // X86_64H:#define __x86_64h__ 1
 
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=x86_64-none-none-gnux32 < /dev/null | FileCheck -match-full-lines -check-prefix X32 %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=x86_64-none-none-gnux32 < /dev/null | FileCheck -match-full-lines -check-prefix X32 -check-prefix X32-CXX %s
 //
 // X32:#define _ILP32 1
 // X32-NOT:#define _LP64 1
@@ -7560,6 +7597,7 @@
 // X32:#define __SSE2__ 1
 // X32:#define __SSE_MATH__ 1
 // X32:#define __SSE__ 1
+// X32-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16U
 // X32:#define __UINT16_C_SUFFIX__
 // X32:#define __UINT16_MAX__ 65535
 // X32:#define __UINT16_TYPE__ unsigned short
@@ -8460,6 +8498,12 @@
 // RUN: %clang_cc1 -triple arm-linux-androideabi -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix ANDROID %s
 // ANDROID:#define __ANDROID__ 1
 //
+// RUN: %clang_cc1 -x c++ -triple i686-linux-android -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix I386-ANDROID-CXX %s
+// I386-ANDROID-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 4U
+//
+// RUN: %clang_cc1 -x c++ -triple x86_64-linux-android -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix X86_64-ANDROID-CXX %s
+// X86_64-ANDROID-CXX:#define __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16UL
+//
 // RUN: %clang_cc1 -triple lanai-unknown-unknown -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix LANAI %s
 // LANAI: #define __lanai__ 1
 //