Address review comment and update failing tests

stdcpp_compat.cpp was malformed with the options used
layout_accessors_host.cpp was expecting output from 3 compilations, which
is now down to 2.

Author: mdtoguchi

clang/include/clang/Driver/Driver.h

@@ -651,7 +651,7 @@ class Driver {
   /// A list of inputs and their corresponding integration headers. These
   /// files are generated during the device compilation and are consumed
   /// by the host compilation.
-  mutable llvm::StringMap<const char *> IntegrationFileList;
+  mutable llvm::StringMap<StringRef> IntegrationFileList;
 
 public:
   /// GetReleaseVersion - Parse (([0-9]+)(.([0-9]+)(.([0-9]+)?))?)? and
@@ -697,7 +697,7 @@ class Driver {
     IntegrationFileList.insert({FileName, IntHeaderName});
   }
   /// getIntegrationHeader - Get the integration header file
-  const char *getIntegrationHeader(const std::string &FileName) const {
+  StringRef getIntegrationHeader(const std::string &FileName) const {
     return IntegrationFileList[FileName];
   }
 };

clang/lib/Driver/ToolChains/Clang.cpp

@@ -6622,15 +6622,15 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     // performing the host side compilation.
     if (!IsSYCLOffloadDevice) {
       // Add the integration header option to generate the header.
-      const char *Header = D.getIntegrationHeader(Input.getBaseInput());
+      StringRef Header = D.getIntegrationHeader(Input.getBaseInput());
       if (types::getPreprocessedType(InputType) != types::TY_INVALID &&
-          Header) {
+          !Header.empty()) {
         CmdArgs.push_back("-include");
-        CmdArgs.push_back(Header);
+        CmdArgs.push_back(Args.MakeArgString(Header));
         // When creating dependency information, filter out the generated
         // header file.
         CmdArgs.push_back("-dependency-filter");
-        CmdArgs.push_back(Header);
+        CmdArgs.push_back(Args.MakeArgString(Header));
       }
       // Let the FE know we are doing a SYCL offload compilation, but we are
       // doing the host pass.
@@ -6653,7 +6653,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     }
     if (IsSYCLOffloadDevice) {
       // Add the integration header option to generate the header.
-      if (const char *Header = D.getIntegrationHeader(Input.getBaseInput())) {
+      StringRef Header(D.getIntegrationHeader(Input.getBaseInput()));
+      if (!Header.empty()) {
         SmallString<128> HeaderOpt("-fsycl-int-header=");
         HeaderOpt.append(Header);
         CmdArgs.push_back(Args.MakeArgString(HeaderOpt));

sycl/test/abi/layout_accessors_host.cpp

@@ -56,7 +56,7 @@ void hostAcc(accessor<int, 1, access::mode::read, access::target::host_buffer> A
   (void)Acc.get_size();
 }
 
-// CHECK-COUNT-3: 0 | class sycl::accessor<int, 1, sycl::access::mode::read, sycl::access::target::host_buffer, sycl::access::placeholder::false_t>
+// CHECK-COUNT-2: 0 | class sycl::accessor<int, 1, sycl::access::mode::read, sycl::access::target::host_buffer, sycl::access::placeholder::false_t>
 // CHECK-NEXT:  0 |   class sycl::detail::AccessorBaseHost (base)
 // CHECK-NEXT:  0 |     class std::shared_ptr<class sycl::detail::AccessorImplHost> impl
 // CHECK-NEXT:  0 |       class std::__shared_ptr<class sycl::detail::AccessorImplHost, __gnu_cxx::_S_atomic> (base)

sycl/test/basic_tests/stdcpp_compat.cpp

@@ -1,7 +1,7 @@
 // RUN: %clangxx -fsycl -fsyntax-only -Xclang -verify -Xclang -verify-ignore-unexpected=note,warning %s -c -o %t.out
-// RUN: %clangxx -std=c++14 -fsyntax-only -Xclang -verify -I %sycl_include -Xclang -verify-ignore-unexpected=note,warning %s -o -c %t.out
-// RUN: %clangxx -std=c++17 -fsyntax-only -Xclang -verify -I %sycl_include -Xclang -verify-ignore-unexpected=note,warning %s -o -c %t.out
-// RUN: %clangxx -std=c++20 -fsyntax-only -Xclang -verify -I %sycl_include -Xclang -verify-ignore-unexpected=note,warning %s -o -c %t.out
+// RUN: %clangxx -std=c++14 -fsyntax-only -Xclang -verify -I %sycl_include -Xclang -verify-ignore-unexpected=note,warning %s -c -o %t.out
+// RUN: %clangxx -std=c++17 -fsyntax-only -Xclang -verify -I %sycl_include -Xclang -verify-ignore-unexpected=note,warning %s -c -o %t.out
+// RUN: %clangxx -std=c++20 -fsyntax-only -Xclang -verify -I %sycl_include -Xclang -verify-ignore-unexpected=note,warning %s -c -o %t.out
 // expected-no-diagnostics
 
 #include <CL/sycl.hpp>