lib/Driver/ToolChains/ZOS.cpp - llvm-project/clang - Git at Google

 //===--- ZOS.cpp - z/OS ToolChain Implementations ---------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #include "ZOS.h"
 #include "CommonArgs.h"
 #include "clang/Driver/Compilation.h"
 #include "clang/Driver/Options.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Support/WithColor.h"

 using namespace clang;
 using namespace clang::driver;
 using namespace clang::driver::tools;
 using namespace clang::driver::toolchains;
 using namespace llvm;
 using namespace llvm::opt;
 using namespace llvm::sys;

 ZOS::ZOS(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
     : ToolChain(D, Triple, Args) {}

 ZOS::~ZOS() {}

 void ZOS::addClangTargetOptions(const ArgList &DriverArgs,
                                 ArgStringList &CC1Args,
                                 Action::OffloadKind DeviceOffloadKind) const {
   // Pass "-faligned-alloc-unavailable" only when the user hasn't manually
   // enabled or disabled aligned allocations.
   if (!DriverArgs.hasArgNoClaim(options::OPT_faligned_allocation,
                                 options::OPT_fno_aligned_allocation))
     CC1Args.push_back("-faligned-alloc-unavailable");
 }

 void zos::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
                                   const InputInfo &Output,
                                   const InputInfoList &Inputs,
                                   const ArgList &Args,
                                   const char *LinkingOutput) const {
   ArgStringList CmdArgs;

   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);

   // Specify assembler output file.
   assert((Output.isFilename() || Output.isNothing()) && "Invalid output.");
   if (Output.isFilename()) {
     CmdArgs.push_back("-o");
     CmdArgs.push_back(Output.getFilename());
   }

   // Specify assembler input file.
   // The system assembler on z/OS takes exactly one input file. The driver is
   // expected to invoke as(1) separately for each assembler source input file.
   if (Inputs.size() != 1)
     llvm_unreachable("Invalid number of input files.");
   const InputInfo &II = Inputs[0];
   assert((II.isFilename() || II.isNothing()) && "Invalid input.");
   if (II.isFilename())
     CmdArgs.push_back(II.getFilename());

   const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath("as"));
   C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
                                          Exec, CmdArgs, Inputs));
 }

 static std::string getLEHLQ(const ArgList &Args) {
   if (Args.hasArg(options::OPT_mzos_hlq_le_EQ)) {
     Arg *LEHLQArg = Args.getLastArg(options::OPT_mzos_hlq_le_EQ);
     StringRef HLQ = LEHLQArg->getValue();
     if (!HLQ.empty())
       return HLQ.str();
   }
   return "CEE";
 }

 static std::string getClangHLQ(const ArgList &Args) {
   if (Args.hasArg(options::OPT_mzos_hlq_clang_EQ)) {
     Arg *ClangHLQArg = Args.getLastArg(options::OPT_mzos_hlq_clang_EQ);
     StringRef HLQ = ClangHLQArg->getValue();
     if (!HLQ.empty())
       return HLQ.str();
   }
   return getLEHLQ(Args);
 }

 static std::string getCSSHLQ(const ArgList &Args) {
   if (Args.hasArg(options::OPT_mzos_hlq_csslib_EQ)) {
     Arg *CsslibHLQArg = Args.getLastArg(options::OPT_mzos_hlq_csslib_EQ);
     StringRef HLQ = CsslibHLQArg->getValue();
     if (!HLQ.empty())
       return HLQ.str();
   }
   return "SYS1";
 }

 void zos::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                const InputInfo &Output,
                                const InputInfoList &Inputs, const ArgList &Args,
                                const char *LinkingOutput) const {
   const ZOS &ToolChain = static_cast<const ZOS &>(getToolChain());
   ArgStringList CmdArgs;

   const bool IsSharedLib =
       Args.hasFlag(options::OPT_shared, options::OPT_static, false);

   assert((Output.isFilename() || Output.isNothing()) && "Invalid output.");
   if (Output.isFilename()) {
     CmdArgs.push_back("-o");
     CmdArgs.push_back(Output.getFilename());
   }

   SmallString<128> LinkerOptions;
   LinkerOptions = "AMODE=";
   LinkerOptions += "64";
   LinkerOptions += ",LIST";
   LinkerOptions += ",DYNAM=DLL";
   LinkerOptions += ",MSGLEVEL=4";
   LinkerOptions += ",CASE=MIXED";
   LinkerOptions += ",REUS=RENT";

   CmdArgs.push_back("-b");
   CmdArgs.push_back(Args.MakeArgString(LinkerOptions));

   if (!IsSharedLib) {
     CmdArgs.push_back("-e");
     CmdArgs.push_back("CELQSTRT");

     CmdArgs.push_back("-O");
     CmdArgs.push_back("CELQSTRT");

     CmdArgs.push_back("-u");
     CmdArgs.push_back("CELQMAIN");
   }

   // Generate side file if -shared option is present.
   if (IsSharedLib) {
     StringRef OutputName = Output.getFilename();
     // Strip away the last file suffix in presence from output name and add
     // a new .x suffix.
     size_t Suffix = OutputName.find_last_of('.');
     const char *SideDeckName =
         Args.MakeArgString(OutputName.substr(0, Suffix) + ".x");
     CmdArgs.push_back("-x");
     CmdArgs.push_back(SideDeckName);
   } else {
     // We need to direct side file to /dev/null to suppress linker warning when
     // the object file contains exported symbols, and -shared or
     // -Wl,-x<sidedeck>.x is not specified.
     CmdArgs.push_back("-x");
     CmdArgs.push_back("/dev/null");
   }

   // Add archive library search paths.
   Args.addAllArgs(CmdArgs, {options::OPT_L, options::OPT_u});

   ToolChain.AddFilePathLibArgs(Args, CmdArgs);

   // Specify linker input file(s)
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);

   //  z/OS tool chain depends on LE data sets and the CSSLIB data set.
   //  These data sets can have different high level qualifiers (HLQs)
   //  as each installation can define them differently.

   std::string LEHLQ = getLEHLQ(Args);
   std::string CsslibHLQ = getCSSHLQ(Args);

   StringRef ld_env_var = StringRef(getenv("_LD_SYSLIB")).trim();
   if (ld_env_var.empty()) {
     CmdArgs.push_back("-S");
     CmdArgs.push_back(Args.MakeArgString("//'" + LEHLQ + ".SCEEBND2'"));
     CmdArgs.push_back("-S");
     CmdArgs.push_back(Args.MakeArgString("//'" + CsslibHLQ + ".CSSLIB'"));
   }

   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
     ld_env_var = StringRef(getenv("_LD_SIDE_DECKS")).trim();
     if (ld_env_var.empty()) {
       CmdArgs.push_back(
           Args.MakeArgString("//'" + LEHLQ + ".SCEELIB(CELQS001)'"));
       CmdArgs.push_back(
           Args.MakeArgString("//'" + LEHLQ + ".SCEELIB(CELQS003)'"));
     } else {
       SmallVector<StringRef> ld_side_deck;
       ld_env_var.split(ld_side_deck, ":");
       for (StringRef ld_loc : ld_side_deck) {
         CmdArgs.push_back((ld_loc.str()).c_str());
       }
     }
   }
   // Link libc++ library
   if (ToolChain.ShouldLinkCXXStdlib(Args)) {
     ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
   }

   // Specify compiler-rt library path for linker
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs))
     AddRunTimeLibs(ToolChain, ToolChain.getDriver(), CmdArgs, Args);

   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
   C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
                                          Exec, CmdArgs, Inputs));
 }

 ToolChain::RuntimeLibType ZOS::GetDefaultRuntimeLibType() const {
   return ToolChain::RLT_CompilerRT;
 }

 ToolChain::CXXStdlibType ZOS::GetDefaultCXXStdlibType() const {
   return ToolChain::CST_Libcxx;
 }

 void ZOS::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
                               llvm::opt::ArgStringList &CmdArgs) const {
   switch (GetCXXStdlibType(Args)) {
   case ToolChain::CST_Libstdcxx:
     llvm::report_fatal_error("linking libstdc++ is unimplemented on z/OS");
     break;
   case ToolChain::CST_Libcxx: {
     std::string ClangHLQ = getClangHLQ(Args);
     CmdArgs.push_back(
         Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXE)'"));
     CmdArgs.push_back(
         Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXS)'"));
     CmdArgs.push_back(
         Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXP)'"));
     CmdArgs.push_back(
         Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXA)'"));
     CmdArgs.push_back(
         Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQXLA)'"));
     CmdArgs.push_back(
         Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQUNW)'"));
   } break;
   }
 }

 auto ZOS::buildAssembler() const -> Tool * { return new zos::Assembler(*this); }

 auto ZOS::buildLinker() const -> Tool * { return new zos::Linker(*this); }

 void ZOS::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
                                     ArgStringList &CC1Args) const {
   if (DriverArgs.hasArg(options::OPT_nostdinc))
     return;

   const Driver &D = getDriver();

   // resolve ResourceDir
   std::string ResourceDir(D.ResourceDir);

   // zos_wrappers must take highest precedence

   // - <clang>/lib/clang/<ver>/include/zos_wrappers
   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
     SmallString<128> P(ResourceDir);
     path::append(P, "include", "zos_wrappers");
     addSystemInclude(DriverArgs, CC1Args, P.str());

     // - <clang>/lib/clang/<ver>/include
     SmallString<128> P2(ResourceDir);
     path::append(P2, "include");
     addSystemInclude(DriverArgs, CC1Args, P2.str());
   }

   // - /usr/include
   if (Arg *SysIncludeArg =
           DriverArgs.getLastArg(options::OPT_mzos_sys_include_EQ)) {
     StringRef SysInclude = SysIncludeArg->getValue();

     // fall back to the default include path
     if (!SysInclude.empty()) {

       // -mzos-sys-include opton can have colon separated
       // list of paths, so we need to parse the value.
       StringRef PathLE(SysInclude);
       size_t Colon = PathLE.find(':');
       if (Colon == StringRef::npos) {
         addSystemInclude(DriverArgs, CC1Args, PathLE.str());
         return;
       }

       while (Colon != StringRef::npos) {
         SmallString<128> P = PathLE.substr(0, Colon);
         addSystemInclude(DriverArgs, CC1Args, P.str());
         PathLE = PathLE.substr(Colon + 1);
         Colon = PathLE.find(':');
       }
       if (PathLE.size())
         addSystemInclude(DriverArgs, CC1Args, PathLE.str());

       return;
     }
   }

   addSystemInclude(DriverArgs, CC1Args, "/usr/include");
 }

 void ZOS::TryAddIncludeFromPath(llvm::SmallString<128> Path,
                                 const llvm::opt::ArgList &DriverArgs,
                                 llvm::opt::ArgStringList &CC1Args) const {
   if (!getVFS().exists(Path)) {
     if (DriverArgs.hasArg(options::OPT_v))
       WithColor::warning(errs(), "Clang")
           << "ignoring nonexistent directory \"" << Path << "\"\n";
     if (!DriverArgs.hasArg(options::OPT__HASH_HASH_HASH))
       return;
   }
   addSystemInclude(DriverArgs, CC1Args, Path);
 }

 void ZOS::AddClangCXXStdlibIncludeArgs(
     const llvm::opt::ArgList &DriverArgs,
     llvm::opt::ArgStringList &CC1Args) const {
   if (DriverArgs.hasArg(options::OPT_nostdinc) ||
       DriverArgs.hasArg(options::OPT_nostdincxx) ||
       DriverArgs.hasArg(options::OPT_nostdlibinc))
     return;

   switch (GetCXXStdlibType(DriverArgs)) {
   case ToolChain::CST_Libcxx: {
     // <install>/bin/../include/c++/v1
     llvm::SmallString<128> InstallBin(getDriver().Dir);
     llvm::sys::path::append(InstallBin, "..", "include", "c++", "v1");
     TryAddIncludeFromPath(InstallBin, DriverArgs, CC1Args);
     break;
   }
   case ToolChain::CST_Libstdcxx:
     llvm::report_fatal_error(
         "picking up libstdc++ headers is unimplemented on z/OS");
     break;
   }
 }
	//===--- ZOS.cpp - z/OS ToolChain Implementations ---------------- C++ --===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#include "ZOS.h"
	#include "CommonArgs.h"
	#include "clang/Driver/Compilation.h"
	#include "clang/Driver/Options.h"
	#include "llvm/Option/ArgList.h"
	#include "llvm/Support/FileSystem.h"
	#include "llvm/Support/VirtualFileSystem.h"
	#include "llvm/Support/WithColor.h"

	using namespace clang;
	using namespace clang::driver;
	using namespace clang::driver::tools;
	using namespace clang::driver::toolchains;
	using namespace llvm;
	using namespace llvm::opt;
	using namespace llvm::sys;

	ZOS::ZOS(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
	: ToolChain(D, Triple, Args) {}

	ZOS::~ZOS() {}

	void ZOS::addClangTargetOptions(const ArgList &DriverArgs,
	ArgStringList &CC1Args,
	Action::OffloadKind DeviceOffloadKind) const {
	// Pass "-faligned-alloc-unavailable" only when the user hasn't manually
	// enabled or disabled aligned allocations.
	if (!DriverArgs.hasArgNoClaim(options::OPT_faligned_allocation,
	options::OPT_fno_aligned_allocation))
	CC1Args.push_back("-faligned-alloc-unavailable");
	}

	void zos::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
	const InputInfo &Output,
	const InputInfoList &Inputs,
	const ArgList &Args,
	const char *LinkingOutput) const {
	ArgStringList CmdArgs;

	Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);

	// Specify assembler output file.
	assert((Output.isFilename() \|\| Output.isNothing()) && "Invalid output.");
	if (Output.isFilename()) {
	CmdArgs.push_back("-o");
	CmdArgs.push_back(Output.getFilename());
	}

	// Specify assembler input file.
	// The system assembler on z/OS takes exactly one input file. The driver is
	// expected to invoke as(1) separately for each assembler source input file.
	if (Inputs.size() != 1)
	llvm_unreachable("Invalid number of input files.");
	const InputInfo &II = Inputs[0];
	assert((II.isFilename() \|\| II.isNothing()) && "Invalid input.");
	if (II.isFilename())
	CmdArgs.push_back(II.getFilename());

	const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath("as"));
	C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
	Exec, CmdArgs, Inputs));
	}

	static std::string getLEHLQ(const ArgList &Args) {
	if (Args.hasArg(options::OPT_mzos_hlq_le_EQ)) {
	Arg *LEHLQArg = Args.getLastArg(options::OPT_mzos_hlq_le_EQ);
	StringRef HLQ = LEHLQArg->getValue();
	if (!HLQ.empty())
	return HLQ.str();
	}
	return "CEE";
	}

	static std::string getClangHLQ(const ArgList &Args) {
	if (Args.hasArg(options::OPT_mzos_hlq_clang_EQ)) {
	Arg *ClangHLQArg = Args.getLastArg(options::OPT_mzos_hlq_clang_EQ);
	StringRef HLQ = ClangHLQArg->getValue();
	if (!HLQ.empty())
	return HLQ.str();
	}
	return getLEHLQ(Args);
	}

	static std::string getCSSHLQ(const ArgList &Args) {
	if (Args.hasArg(options::OPT_mzos_hlq_csslib_EQ)) {
	Arg *CsslibHLQArg = Args.getLastArg(options::OPT_mzos_hlq_csslib_EQ);
	StringRef HLQ = CsslibHLQArg->getValue();
	if (!HLQ.empty())
	return HLQ.str();
	}
	return "SYS1";
	}

	void zos::Linker::ConstructJob(Compilation &C, const JobAction &JA,
	const InputInfo &Output,
	const InputInfoList &Inputs, const ArgList &Args,
	const char *LinkingOutput) const {
	const ZOS &ToolChain = static_cast<const ZOS &>(getToolChain());
	ArgStringList CmdArgs;

	const bool IsSharedLib =
	Args.hasFlag(options::OPT_shared, options::OPT_static, false);

	assert((Output.isFilename() \|\| Output.isNothing()) && "Invalid output.");
	if (Output.isFilename()) {
	CmdArgs.push_back("-o");
	CmdArgs.push_back(Output.getFilename());
	}

	SmallString<128> LinkerOptions;
	LinkerOptions = "AMODE=";
	LinkerOptions += "64";
	LinkerOptions += ",LIST";
	LinkerOptions += ",DYNAM=DLL";
	LinkerOptions += ",MSGLEVEL=4";
	LinkerOptions += ",CASE=MIXED";
	LinkerOptions += ",REUS=RENT";

	CmdArgs.push_back("-b");
	CmdArgs.push_back(Args.MakeArgString(LinkerOptions));

	if (!IsSharedLib) {
	CmdArgs.push_back("-e");
	CmdArgs.push_back("CELQSTRT");

	CmdArgs.push_back("-O");
	CmdArgs.push_back("CELQSTRT");

	CmdArgs.push_back("-u");
	CmdArgs.push_back("CELQMAIN");
	}

	// Generate side file if -shared option is present.
	if (IsSharedLib) {
	StringRef OutputName = Output.getFilename();
	// Strip away the last file suffix in presence from output name and add
	// a new .x suffix.
	size_t Suffix = OutputName.find_last_of('.');
	const char *SideDeckName =
	Args.MakeArgString(OutputName.substr(0, Suffix) + ".x");
	CmdArgs.push_back("-x");
	CmdArgs.push_back(SideDeckName);
	} else {
	// We need to direct side file to /dev/null to suppress linker warning when
	// the object file contains exported symbols, and -shared or
	// -Wl,-x<sidedeck>.x is not specified.
	CmdArgs.push_back("-x");
	CmdArgs.push_back("/dev/null");
	}

	// Add archive library search paths.
	Args.addAllArgs(CmdArgs, {options::OPT_L, options::OPT_u});

	ToolChain.AddFilePathLibArgs(Args, CmdArgs);

	// Specify linker input file(s)
	AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);

	// z/OS tool chain depends on LE data sets and the CSSLIB data set.
	// These data sets can have different high level qualifiers (HLQs)
	// as each installation can define them differently.

	std::string LEHLQ = getLEHLQ(Args);
	std::string CsslibHLQ = getCSSHLQ(Args);

	StringRef ld_env_var = StringRef(getenv("_LD_SYSLIB")).trim();
	if (ld_env_var.empty()) {
	CmdArgs.push_back("-S");
	CmdArgs.push_back(Args.MakeArgString("//'" + LEHLQ + ".SCEEBND2'"));
	CmdArgs.push_back("-S");
	CmdArgs.push_back(Args.MakeArgString("//'" + CsslibHLQ + ".CSSLIB'"));
	}

	if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
	ld_env_var = StringRef(getenv("_LD_SIDE_DECKS")).trim();
	if (ld_env_var.empty()) {
	CmdArgs.push_back(
	Args.MakeArgString("//'" + LEHLQ + ".SCEELIB(CELQS001)'"));
	CmdArgs.push_back(
	Args.MakeArgString("//'" + LEHLQ + ".SCEELIB(CELQS003)'"));
	} else {
	SmallVector<StringRef> ld_side_deck;
	ld_env_var.split(ld_side_deck, ":");
	for (StringRef ld_loc : ld_side_deck) {
	CmdArgs.push_back((ld_loc.str()).c_str());
	}
	}
	}
	// Link libc++ library
	if (ToolChain.ShouldLinkCXXStdlib(Args)) {
	ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
	}

	// Specify compiler-rt library path for linker
	if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs))
	AddRunTimeLibs(ToolChain, ToolChain.getDriver(), CmdArgs, Args);

	const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
	C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
	Exec, CmdArgs, Inputs));
	}

	ToolChain::RuntimeLibType ZOS::GetDefaultRuntimeLibType() const {
	return ToolChain::RLT_CompilerRT;
	}

	ToolChain::CXXStdlibType ZOS::GetDefaultCXXStdlibType() const {
	return ToolChain::CST_Libcxx;
	}

	void ZOS::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
	llvm::opt::ArgStringList &CmdArgs) const {
	switch (GetCXXStdlibType(Args)) {
	case ToolChain::CST_Libstdcxx:
	llvm::report_fatal_error("linking libstdc++ is unimplemented on z/OS");
	break;
	case ToolChain::CST_Libcxx: {
	std::string ClangHLQ = getClangHLQ(Args);
	CmdArgs.push_back(
	Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXE)'"));
	CmdArgs.push_back(
	Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXS)'"));
	CmdArgs.push_back(
	Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXP)'"));
	CmdArgs.push_back(
	Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXA)'"));
	CmdArgs.push_back(
	Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQXLA)'"));
	CmdArgs.push_back(
	Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQUNW)'"));
	} break;
	}
	}

	auto ZOS::buildAssembler() const -> Tool * { return new zos::Assembler(*this); }

	auto ZOS::buildLinker() const -> Tool * { return new zos::Linker(*this); }

	void ZOS::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
	ArgStringList &CC1Args) const {
	if (DriverArgs.hasArg(options::OPT_nostdinc))
	return;

	const Driver &D = getDriver();

	// resolve ResourceDir
	std::string ResourceDir(D.ResourceDir);

	// zos_wrappers must take highest precedence

	// - <clang>/lib/clang/<ver>/include/zos_wrappers
	if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
	SmallString<128> P(ResourceDir);
	path::append(P, "include", "zos_wrappers");
	addSystemInclude(DriverArgs, CC1Args, P.str());

	// - <clang>/lib/clang/<ver>/include
	SmallString<128> P2(ResourceDir);
	path::append(P2, "include");
	addSystemInclude(DriverArgs, CC1Args, P2.str());
	}

	// - /usr/include
	if (Arg *SysIncludeArg =
	DriverArgs.getLastArg(options::OPT_mzos_sys_include_EQ)) {
	StringRef SysInclude = SysIncludeArg->getValue();

	// fall back to the default include path
	if (!SysInclude.empty()) {

	// -mzos-sys-include opton can have colon separated
	// list of paths, so we need to parse the value.
	StringRef PathLE(SysInclude);
	size_t Colon = PathLE.find(':');
	if (Colon == StringRef::npos) {
	addSystemInclude(DriverArgs, CC1Args, PathLE.str());
	return;
	}

	while (Colon != StringRef::npos) {
	SmallString<128> P = PathLE.substr(0, Colon);
	addSystemInclude(DriverArgs, CC1Args, P.str());
	PathLE = PathLE.substr(Colon + 1);
	Colon = PathLE.find(':');
	}
	if (PathLE.size())
	addSystemInclude(DriverArgs, CC1Args, PathLE.str());

	return;
	}
	}

	addSystemInclude(DriverArgs, CC1Args, "/usr/include");
	}

	void ZOS::TryAddIncludeFromPath(llvm::SmallString<128> Path,
	const llvm::opt::ArgList &DriverArgs,
	llvm::opt::ArgStringList &CC1Args) const {
	if (!getVFS().exists(Path)) {
	if (DriverArgs.hasArg(options::OPT_v))
	WithColor::warning(errs(), "Clang")
	<< "ignoring nonexistent directory \"" << Path << "\"\n";
	if (!DriverArgs.hasArg(options::OPT__HASH_HASH_HASH))
	return;
	}
	addSystemInclude(DriverArgs, CC1Args, Path);
	}

	void ZOS::AddClangCXXStdlibIncludeArgs(
	const llvm::opt::ArgList &DriverArgs,
	llvm::opt::ArgStringList &CC1Args) const {
	if (DriverArgs.hasArg(options::OPT_nostdinc) \|\|
	DriverArgs.hasArg(options::OPT_nostdincxx) \|\|
	DriverArgs.hasArg(options::OPT_nostdlibinc))
	return;

	switch (GetCXXStdlibType(DriverArgs)) {
	case ToolChain::CST_Libcxx: {
	// <install>/bin/../include/c++/v1
	llvm::SmallString<128> InstallBin(getDriver().Dir);
	llvm::sys::path::append(InstallBin, "..", "include", "c++", "v1");
	TryAddIncludeFromPath(InstallBin, DriverArgs, CC1Args);
	break;
	}
	case ToolChain::CST_Libstdcxx:
	llvm::report_fatal_error(
	"picking up libstdc++ headers is unimplemented on z/OS");
	break;
	}
	}