[SystemZ][z/OS] __ptr32 support for z/OS (#101696)

Enabling __ptr32 keyword to support in Clang for z/OS. It is represented
by addrspace(1) in LLVM IR. Unlike existing implementation, __ptr32 is
not mangled into symbol names for z/OS.

Author: abhina-sree

clang/include/clang/Basic/LangOptions.def

@@ -91,6 +91,7 @@ LANGOPT(C2y               , 1, 0, "C2y")
 LANGOPT(MSVCCompat        , 1, 0, "Microsoft Visual C++ full compatibility mode")
 LANGOPT(Kernel            , 1, 0, "Kernel mode")
 LANGOPT(MicrosoftExt      , 1, 0, "Microsoft C++ extensions")
+LANGOPT(ZOSExt            , 1, 0, "z/OS extensions")
 LANGOPT(AsmBlocks         , 1, 0, "Microsoft inline asm blocks")
 LANGOPT(Borland           , 1, 0, "Borland extensions")
 LANGOPT(CPlusPlus         , 1, 0, "C++")

clang/include/clang/Basic/TokenKinds.def

@@ -292,6 +292,7 @@ PUNCTUATOR(caretcaret,            "^^")
 //   CHAR8SUPPORT - This is a keyword if 'char8_t' is a built-in type
 //   KEYFIXEDPOINT - This is a keyword according to the N1169 fixed point
 //                   extension.
+//   KEYZOS - This is a keyword in C/C++ on z/OS
 //
 KEYWORD(auto                        , KEYALL)
 KEYWORD(break                       , KEYALL)
@@ -725,7 +726,7 @@ KEYWORD(__funcref                     , KEYALL)
 
 // Microsoft extensions which should be disabled in strict conformance mode
 KEYWORD(__ptr64                       , KEYMS)
-KEYWORD(__ptr32                       , KEYMS)
+KEYWORD(__ptr32                       , KEYMS | KEYZOS)
 KEYWORD(__sptr                        , KEYMS)
 KEYWORD(__uptr                        , KEYMS)
 KEYWORD(__w64                         , KEYMS)

clang/include/clang/Driver/Options.td

@@ -3066,6 +3066,10 @@ dll version.}]>;
 def fms_omit_default_lib : Joined<["-"], "fms-omit-default-lib">,
   Group<f_Group>, Flags<[]>,
   Visibility<[ClangOption, CLOption]>;
+def fzos_extensions : Flag<["-"], "fzos-extensions">, Group<f_Group>, Visibility<[ClangOption, CC1Option]>,
+  HelpText<"Accept some non-standard constructs supported by the z/OS compiler">;
+def fno_zos_extensions : Flag<["-"], "fno-zos-extensions">, Group<f_Group>, Visibility<[ClangOption, CC1Option]>,
+  HelpText<"Do not accept non-standard constructs supported by the z/OS compiler">;
 defm delayed_template_parsing : BoolFOption<"delayed-template-parsing",
   LangOpts<"DelayedTemplateParsing">, DefaultFalse,
   PosFlag<SetTrue, [], [ClangOption, CC1Option],

clang/lib/AST/ItaniumMangle.cpp

@@ -2727,6 +2727,8 @@ void CXXNameMangler::mangleQualifiers(Qualifiers Quals, const DependentAddressSp
     //   <type> ::= U <OpenCL-addrspace>
     //   <type> ::= U <CUDA-addrspace>
 
+    llvm::Triple Triple = getASTContext().getTargetInfo().getTriple();
+
     SmallString<64> ASString;
     LangAS AS = Quals.getAddressSpace();
 
@@ -2795,7 +2797,11 @@ void CXXNameMangler::mangleQualifiers(Qualifiers Quals, const DependentAddressSp
         ASString = "ptr32_sptr";
         break;
       case LangAS::ptr32_uptr:
-        ASString = "ptr32_uptr";
+        // For z/OS, there are no special mangling rules applied to the ptr32
+        // qualifier. Ex: void foo(int * __ptr32 p) -> _Z3f2Pi. The mangling for
+        // "p" is treated the same as a regular integer pointer.
+        if (!Triple.isOSzOS())
+          ASString = "ptr32_uptr";
         break;
       case LangAS::ptr64:
         ASString = "ptr64";

clang/lib/Basic/IdentifierTable.cpp

@@ -107,12 +107,14 @@ enum TokenKey : unsigned {
   KEYMSCOMPAT = 0x400000,
   KEYSYCL = 0x800000,
   KEYCUDA = 0x1000000,
-  KEYHLSL = 0x2000000,
-  KEYFIXEDPOINT = 0x4000000,
+  KEYZOS = 0x2000000,
+  KEYNOZOS = 0x4000000,
+  KEYHLSL = 0x8000000,
+  KEYFIXEDPOINT = 0x10000000,
   KEYMAX = KEYFIXEDPOINT, // The maximum key
   KEYALLCXX = KEYCXX | KEYCXX11 | KEYCXX20,
-  KEYALL = (KEYMAX | (KEYMAX - 1)) & ~KEYNOMS18 &
-           ~KEYNOOPENCL // KEYNOMS18 and KEYNOOPENCL are used to exclude.
+  KEYALL = (KEYMAX | (KEYMAX - 1)) & ~KEYNOMS18 & ~KEYNOOPENCL &
+           ~KEYNOZOS // KEYNOMS18, KEYNOOPENCL, KEYNOZOS are excluded.
 };
 
 /// How a keyword is treated in the selected standard. This enum is ordered
@@ -199,16 +201,17 @@ static KeywordStatus getKeywordStatusHelper(const LangOptions &LangOpts,
     return LangOpts.isSYCL() ? KS_Enabled : KS_Unknown;
   case KEYCUDA:
     return LangOpts.CUDA ? KS_Enabled : KS_Unknown;
+  case KEYZOS:
+    return LangOpts.ZOSExt ? KS_Enabled : KS_Unknown;
   case KEYHLSL:
     return LangOpts.HLSL ? KS_Enabled : KS_Unknown;
   case KEYNOCXX:
     // This is enabled in all non-C++ modes, but might be enabled for other
     // reasons as well.
     return LangOpts.CPlusPlus ? KS_Unknown : KS_Enabled;
   case KEYNOOPENCL:
-    // The disable behavior for this is handled in getKeywordStatus.
-    return KS_Unknown;
   case KEYNOMS18:
+  case KEYNOZOS:
     // The disable behavior for this is handled in getKeywordStatus.
     return KS_Unknown;
   case KEYFIXEDPOINT:
@@ -230,7 +233,8 @@ static KeywordStatus getKeywordStatus(const LangOptions &LangOpts,
   if (LangOpts.MSVCCompat && (Flags & KEYNOMS18) &&
       !LangOpts.isCompatibleWithMSVC(LangOptions::MSVC2015))
     return KS_Disabled;
-
+  if (LangOpts.ZOSExt && (Flags & KEYNOZOS))
+    return KS_Disabled;
   KeywordStatus CurStatus = KS_Unknown;
 
   while (Flags != 0) {

clang/lib/Basic/Targets/SystemZ.h

@@ -21,6 +21,30 @@
 namespace clang {
 namespace targets {
 
+static const unsigned ZOSAddressMap[] = {
+    0, // Default
+    0, // opencl_global
+    0, // opencl_local
+    0, // opencl_constant
+    0, // opencl_private
+    0, // opencl_generic
+    0, // opencl_global_device
+    0, // opencl_global_host
+    0, // cuda_device
+    0, // cuda_constant
+    0, // cuda_shared
+    0, // sycl_global
+    0, // sycl_global_device
+    0, // sycl_global_host
+    0, // sycl_local
+    0, // sycl_private
+    0, // ptr32_sptr
+    1, // ptr32_uptr
+    0, // ptr64
+    0, // hlsl_groupshared
+    0  // wasm_funcref
+};
+
 class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public TargetInfo {
 
   static const char *const GCCRegNames[];
@@ -30,6 +54,7 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public TargetInfo {
   bool HasVector;
   bool SoftFloat;
   bool UnalignedSymbols;
+  enum AddrSpace { ptr32 = 1 };
 
 public:
   SystemZTargetInfo(const llvm::Triple &Triple, const TargetOptions &)
@@ -49,14 +74,17 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public TargetInfo {
     MinGlobalAlign = 16;
     HasUnalignedAccess = true;
     if (Triple.isOSzOS()) {
+      if (Triple.isArch64Bit()) {
+        AddrSpaceMap = &ZOSAddressMap;
+      }
       TLSSupported = false;
       // All vector types are default aligned on an 8-byte boundary, even if the
       // vector facility is not available. That is different from Linux.
       MaxVectorAlign = 64;
       // Compared to Linux/ELF, the data layout differs only in some details:
       // - name mangling is GOFF.
       // - 32 bit pointers, either as default or special address space
-      resetDataLayout("E-m:l-i1:8:16-i8:8:16-i64:64-f128:64-v128:64-"
+      resetDataLayout("E-m:l-p1:32:32-i1:8:16-i8:8:16-i64:64-f128:64-v128:64-"
                       "a:8:16-n32:64");
     } else {
       TLSSupported = true;
@@ -224,6 +252,16 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public TargetInfo {
   std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
     return std::make_pair(256, 256);
   }
+  uint64_t getPointerWidthV(LangAS AddrSpace) const override {
+    return (getTriple().isOSzOS() && getTriple().isArch64Bit() &&
+            getTargetAddressSpace(AddrSpace) == ptr32)
+               ? 32
+               : PointerWidth;
+  }
+
+  uint64_t getPointerAlignV(LangAS AddrSpace) const override {
+    return getPointerWidthV(AddrSpace);
+  }
 };
 } // namespace targets
 } // namespace clang

clang/lib/Driver/ToolChains/Clang.cpp

@@ -7514,6 +7514,12 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       (C.isForDiagnostics() && !HaveModules))
     CmdArgs.push_back("-frewrite-includes");
 
+  if (Args.hasFlag(options::OPT_fzos_extensions,
+                   options::OPT_fno_zos_extensions, false))
+    CmdArgs.push_back("-fzos-extensions");
+  else if (Args.hasArg(options::OPT_fno_zos_extensions))
+    CmdArgs.push_back("-fno-zos-extensions");
+
   // Only allow -traditional or -traditional-cpp outside in preprocessing modes.
   if (Arg *A = Args.getLastArg(options::OPT_traditional,
                                options::OPT_traditional_cpp)) {

clang/lib/Frontend/CompilerInvocation.cpp

@@ -3650,6 +3650,11 @@ void CompilerInvocationBase::GenerateLangArgs(const LangOptions &Opts,
       GenerateArg(Consumer, OPT_ftrigraphs);
   }
 
+  if (T.isOSzOS() && !Opts.ZOSExt)
+    GenerateArg(Consumer, OPT_fno_zos_extensions);
+  else if (Opts.ZOSExt)
+    GenerateArg(Consumer, OPT_fzos_extensions);
+
   if (Opts.Blocks && !(Opts.OpenCL && Opts.OpenCLVersion == 200))
     GenerateArg(Consumer, OPT_fblocks);
 
@@ -4051,6 +4056,9 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
   Opts.Trigraphs =
       Args.hasFlag(OPT_ftrigraphs, OPT_fno_trigraphs, Opts.Trigraphs);
 
+  Opts.ZOSExt =
+      Args.hasFlag(OPT_fzos_extensions, OPT_fno_zos_extensions, T.isOSzOS());
+
   Opts.Blocks = Args.hasArg(OPT_fblocks) || (Opts.OpenCL
     && Opts.OpenCLVersion == 200);
 

clang/lib/Sema/SemaType.cpp

@@ -7057,6 +7057,7 @@ static bool handleMSPointerTypeQualifierAttr(TypeProcessingState &State,
 
   // Add address space to type based on its attributes.
   LangAS ASIdx = LangAS::Default;
+  llvm::Triple Triple = S.Context.getTargetInfo().getTriple();
   uint64_t PtrWidth =
       S.Context.getTargetInfo().getPointerWidth(LangAS::Default);
   if (PtrWidth == 32) {
@@ -7065,7 +7066,7 @@ static bool handleMSPointerTypeQualifierAttr(TypeProcessingState &State,
     else if (Attrs[attr::UPtr])
       ASIdx = LangAS::ptr32_uptr;
   } else if (PtrWidth == 64 && Attrs[attr::Ptr32]) {
-    if (Attrs[attr::UPtr])
+    if (Triple.isOSzOS() || Attrs[attr::UPtr])
       ASIdx = LangAS::ptr32_uptr;
     else
       ASIdx = LangAS::ptr32_sptr;

clang/test/CodeGen/SystemZ/zos-mixed-ptr-sizes-definitions.c

@@ -0,0 +1,53 @@
+// RUN: %clang_cc1 -triple s390x-ibm-zos -emit-llvm < %s | FileCheck %s --check-prefix=PTR32-ZOS
+// RUN: %clang_cc1 -triple s390x-ibm-linux -fzos-extensions -emit-llvm < %s | FileCheck %s --check-prefix=PTR32-LINUX
+// RUN: %clang_cc1 -triple s390x-linux-gnu -fzos-extensions -emit-llvm < %s | FileCheck %s --check-prefix=PTR32-LINUX
+
+void ptr32_declarations() {
+  // PTR32-ZOS-LABEL: @ptr32_declarations()
+  // PTR32-LINUX-LABEL: @ptr32_declarations()
+
+  // PTR32-ZOS: %p1 = alloca ptr addrspace(1), align 4
+  // PTR32-LINUX-NOT: %p1 = alloca i8 addrspace(1)*, align 4
+  // PTR32-LINUX: %p1 = alloca ptr, align 8
+  char * __ptr32 p1;
+
+  // PTR32-ZOS: %p2 = alloca ptr, align 8
+  // PTR32-LINUX-NOT: %p2 = alloca ptr addrspace(1), align 8
+  // PTR32-LINUX: %p2 = alloca ptr, align 8
+  char * __ptr32 *p2;
+
+  // PTR32-ZOS: %p3 = alloca ptr addrspace(1), align 4
+  // PTR32-LINUX-NOT: %p3 = alloca i8* addrspace(1)*, align 4
+  // PTR32-LINUX: %p3 = alloca ptr, align 8
+  char ** __ptr32 p3;
+
+  // PTR32-ZOS: %p4 = alloca ptr, align 8
+  // PTR32-LINUX-NOT: %p4 = alloca ptr addrspace(1), align 8
+  // PTR32-LINUX: %p4 = alloca ptr, align 8
+  char ** __ptr32 *p4;
+
+  // PTR32-ZOS: %p5 = alloca ptr, align 8
+  // PTR32-LINUX-NOT:  %p5 = alloca ptr addrspace(1), align 8
+  // PTR32-LINUX: %p5 = alloca ptr, align 8
+  char *** __ptr32 *p5;
+
+  // PTR32-ZOS: %p6 = alloca ptr, align 8
+  // PTR32-LINUX: %p6 = alloca ptr, align 8
+  char **p6;
+
+  // PTR32-ZOS: %p7 = alloca ptr addrspace(1), align 4
+  // PTR32-LINUX-NOT: %p7 = alloca i8 addrspace(1)* addrspace(1)*, align 4
+  // PTR32-LINUX: %p7 = alloca ptr, align 8
+  char * __ptr32 * __ptr32 p7;
+
+  // PTR32-ZOS: %p8 = alloca ptr addrspace(1), align 4
+  // PTR32-LINUX-NOT: %p8 = alloca i8* addrspace(1)* addrspace(1)*, align 4
+  // PTR32-LINUX: %p8 = alloca ptr, align 8
+  char ** __ptr32 * __ptr32 p8;
+
+  // PTR32-ZOS: %p9 = alloca ptr, align 8
+  // PTR32-LINUX-NOT: %p9 = alloca i8* addrspace(1)* addrspace(1)**, align 8
+  // PTR32-LINUX: %p9 = alloca ptr, align 8
+  char ** __ptr32 * __ptr32 *p9;
+
+}