Add AIX Target Info

Summary:
A first pass over platform-specific properties of the C API/ABI
on AIX for both 32-bit and 64-bit modes.
This is a continuation of D18360 by Andrew Paprocki and further work by Wu Zhao.

Patch by Andus Yu

Reviewers: apaprocki, chandlerc, hubert.reinterpretcast, jasonliu,
xingxue, sfertile

Reviewed by: hubert.reinterpretcast, apaprocki, sfertile

Differential Revision: https://reviews.llvm.org/D59048

llvm-svn: 356060

clang/lib/Basic/Targets.cpp

@@ -332,6 +332,8 @@ TargetInfo *AllocateTarget(const llvm::Triple &Triple,
       return new OpenBSDTargetInfo<PPC32TargetInfo>(Triple, Opts);
     case llvm::Triple::RTEMS:
       return new RTEMSTargetInfo<PPC32TargetInfo>(Triple, Opts);
+    case llvm::Triple::AIX:
+      return new AIXPPC32TargetInfo(Triple, Opts);
     default:
       return new PPC32TargetInfo(Triple, Opts);
     }
@@ -348,6 +350,8 @@ TargetInfo *AllocateTarget(const llvm::Triple &Triple,
       return new FreeBSDTargetInfo<PPC64TargetInfo>(Triple, Opts);
     case llvm::Triple::NetBSD:
       return new NetBSDTargetInfo<PPC64TargetInfo>(Triple, Opts);
+    case llvm::Triple::AIX:
+      return new AIXPPC64TargetInfo(Triple, Opts);
     default:
       return new PPC64TargetInfo(Triple, Opts);
     }

clang/lib/Basic/Targets/OSTargets.h

@@ -613,6 +613,53 @@ class LLVM_LIBRARY_VISIBILITY SolarisTargetInfo : public OSTargetInfo<Target> {
   }
 };
 
+// AIX Target
+template <typename Target>
+class AIXTargetInfo : public OSTargetInfo<Target> {
+protected:
+  void getOSDefines(const LangOptions &Opts, const llvm::Triple &Triple,
+                    MacroBuilder &Builder) const override {
+    DefineStd(Builder, "unix", Opts);
+    Builder.defineMacro("_IBMR2");
+    Builder.defineMacro("_POWER");
+
+    // FIXME: Define AIX OS-Version Macros.
+    Builder.defineMacro("_AIX");
+
+    // FIXME: Do not define _LONG_LONG when -fno-long-long is specified.
+    Builder.defineMacro("_LONG_LONG");
+
+    if (Opts.POSIXThreads) {
+      Builder.defineMacro("_THREAD_SAFE");
+    }
+
+    if (this->PointerWidth == 64) {
+      Builder.defineMacro("__64BIT__");
+    }
+
+    // Define _WCHAR_T when it is a fundamental type
+    // (i.e., for C++ without -fno-wchar).
+    if (Opts.CPlusPlus && Opts.WChar) {
+      Builder.defineMacro("_WCHAR_T");
+    }
+  }
+
+public:
+  AIXTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
+      : OSTargetInfo<Target>(Triple, Opts) {
+    if (this->PointerWidth == 64) {
+      this->WCharType = this->UnsignedInt;
+    } else {
+      this->WCharType = this->UnsignedShort;
+    }
+    this->UseZeroLengthBitfieldAlignment = true;
+  }
+
+  // AIX sets FLT_EVAL_METHOD to be 1.
+  unsigned getFloatEvalMethod() const override { return 1; }
+  bool hasInt128Type() const override { return false; }
+};
+
 // Windows target
 template <typename Target>
 class LLVM_LIBRARY_VISIBILITY WindowsTargetInfo : public OSTargetInfo<Target> {

clang/lib/Basic/Targets/PPC.cpp

@@ -100,7 +100,9 @@ void PPCTargetInfo::getTargetDefines(const LangOptions &Opts,
     Builder.defineMacro("_CALL_LINUX", "1");
 
   // Subtarget options.
-  Builder.defineMacro("__NATURAL_ALIGNMENT__");
+  if (!getTriple().isOSAIX()){
+    Builder.defineMacro("__NATURAL_ALIGNMENT__");
+  }
   Builder.defineMacro("__REGISTER_PREFIX__", "");
 
   // FIXME: Should be controlled by command line option.

clang/lib/Basic/Targets/PPC.h

@@ -325,6 +325,12 @@ class LLVM_LIBRARY_VISIBILITY PPC32TargetInfo : public PPCTargetInfo {
       PtrDiffType = SignedInt;
       IntPtrType = SignedInt;
       break;
+    case llvm::Triple::AIX:
+      SizeType = UnsignedLong;
+      PtrDiffType = SignedLong;
+      IntPtrType = SignedLong;
+      SuitableAlign = 64;
+      break;
     default:
       break;
     }
@@ -333,6 +339,8 @@ class LLVM_LIBRARY_VISIBILITY PPC32TargetInfo : public PPCTargetInfo {
     case llvm::Triple::FreeBSD:
     case llvm::Triple::NetBSD:
     case llvm::Triple::OpenBSD:
+    // FIXME: -mlong-double-128 is not yet supported on AIX.
+    case llvm::Triple::AIX:
       LongDoubleWidth = LongDoubleAlign = 64;
       LongDoubleFormat = &llvm::APFloat::IEEEdouble();
       break;
@@ -373,6 +381,12 @@ class LLVM_LIBRARY_VISIBILITY PPC64TargetInfo : public PPCTargetInfo {
       LongDoubleWidth = LongDoubleAlign = 64;
       LongDoubleFormat = &llvm::APFloat::IEEEdouble();
       break;
+    case llvm::Triple::AIX:
+      // FIXME: -mlong-double-128 is not yet supported on AIX.
+      LongDoubleWidth = LongDoubleAlign = 64;
+      LongDoubleFormat = &llvm::APFloat::IEEEdouble();
+      SuitableAlign = 64;
+      break;
     default:
       break;
     }
@@ -431,6 +445,21 @@ class LLVM_LIBRARY_VISIBILITY DarwinPPC64TargetInfo
   }
 };
 
+class LLVM_LIBRARY_VISIBILITY AIXPPC32TargetInfo :
+  public AIXTargetInfo<PPC32TargetInfo> {
+public:
+  using AIXTargetInfo::AIXTargetInfo;
+  BuiltinVaListKind getBuiltinVaListKind() const override {
+    return TargetInfo::CharPtrBuiltinVaList;
+  }
+};
+
+class LLVM_LIBRARY_VISIBILITY AIXPPC64TargetInfo :
+  public AIXTargetInfo<PPC64TargetInfo> {
+public:
+  using AIXTargetInfo::AIXTargetInfo;
+};
+
 } // namespace targets
 } // namespace clang
 #endif // LLVM_CLANG_LIB_BASIC_TARGETS_PPC_H

clang/test/Driver/types.c

@@ -9,6 +9,12 @@
 // RUN: not %clang -c --target=riscv32-unknown-linux-gnu -fsyntax-only %s \
 // RUN: -fforce-enable-int128 -fno-force-enable-int128
 
+// RUN: not %clang -c --target=powerpc-ibm-aix -fsyntax-only %s \
+// RUN: 2>&1 | FileCheck %s
+
+// RUN: not %clang -c --target=powerpc64-ibm-aix -fsyntax-only %s \
+// RUN: 2>&1 | FileCheck %s
+
 void a() {
   __int128_t s;
   __uint128_t t;

clang/test/Headers/max_align.c

@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// expected-no-diagnostics
+
+#ifndef __BIGGEST_ALIGNMENT__
+#error __BIGGEST_ALIGNMENT__ not defined
+#endif
+
+#include <stddef.h>
+
+_Static_assert(__BIGGEST_ALIGNMENT__ == _Alignof(max_align_t), "");