[Driver] Honor -nostdinc and -isystem-after on CrossWindows

[kastiglione]

Summary

This changes CrossWindows to look for -nostdinc instead of -nostdlibinc. In
addition, fixes a bug where -isystem-after options would be dropped when
called with -nostdinc.

[kastiglione]

fixup a test

[compnerd]

This seems like a good idea. Thanks!

[compnerd]

SVN r306829

lib/Driver/ToolChains/CrossWindows.cpp

 }
 
 void CrossWindowsToolChain::
 AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,
                           llvm::opt::ArgStringList &CC1Args) const {
   const Driver &D = getDriver();
   const std::string &SysRoot = D.SysRoot;
 
-  if (DriverArgs.hasArg(options::OPT_nostdlibinc))
+  auto AddSystemAfterIncludes = [&]() {
+    for (const auto &P : DriverArgs.getAllArgValues(options::OPT_isystem_after))
+      addSystemInclude(DriverArgs, CC1Args, P);
+  };
+
+  if (DriverArgs.hasArg(options::OPT_nostdinc)) {
+    AddSystemAfterIncludes();
     return;
+  }
 
   addSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/local/include");
   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
     SmallString<128> ResourceDir(D.ResourceDir);
     llvm::sys::path::append(ResourceDir, "include");
     addSystemInclude(DriverArgs, CC1Args, ResourceDir);
   }
-  for (const auto &P : DriverArgs.getAllArgValues(options::OPT_isystem_after))
-    addSystemInclude(DriverArgs, CC1Args, P);
+  AddSystemAfterIncludes();
   addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/include");
 }
 
 void CrossWindowsToolChain::
 AddClangCXXStdlibIncludeArgs(const llvm::opt::ArgList &DriverArgs,
                              llvm::opt::ArgStringList &CC1Args) const {
   const llvm::Triple &Triple = getTriple();
   const std::string &SysRoot = getDriver().SysRoot;
 
-  if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
+  if (DriverArgs.hasArg(options::OPT_nostdinc) ||
       DriverArgs.hasArg(options::OPT_nostdincxx))
     return;
 
   switch (GetCXXStdlibType(DriverArgs)) {
   case ToolChain::CST_Libcxx:
     addSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/include/c++/v1");
     break;
 

test/Driver/windows-cross.c

 // RUN: %clang -### -target armv7-windows-itanium -isystem-after "Windows Kits/10/Include/10.0.10586.0/ucrt" -isystem-after "Windows Kits/10/Include/10.0.10586.0/um" -isystem-after "Windows Kits/10/Include/10.0.10586.0/shared" -c %s -o /dev/null 2>&1 \
 // RUN:     | FileCheck %s --check-prefix CHECK-ISYSTEM-AFTER
 // CHECK-ISYSTEM-AFTER: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
 // CHECK-ISYSTEM-AFTER: "-internal-isystem" "[[RESOURCE_DIR]]{{(/|\\\\)}}include"
 // CHECK-ISYSTEM-AFTER: "-internal-isystem" "Windows Kits{{[/\\]}}10{{[/\\]}}Include{{[/\\]}}10.0.10586.0{{[/\\]}}ucrt"
 // CHECK-ISYSTEM-AFTER: "-internal-isystem" "Windows Kits{{[/\\]}}10{{[/\\]}}Include{{[/\\]}}10.0.10586.0{{[/\\]}}um"
 // CHECK-ISYSTEM-AFTER: "-internal-isystem" "Windows Kits{{[/\\]}}10{{[/\\]}}Include{{[/\\]}}10.0.10586.0{{[/\\]}}shared"
 
+// RUN: %clang -### -target armv7-windows-itanium -nostdinc -isystem-after "Windows Kits/10/Include/10.0.10586.0/ucrt" -c %s -o /dev/null 2>&1 \
+// RUN:     | FileCheck %s --check-prefix CHECK-NOSTDINC-ISYSTEM-AFTER
+// CHECK-NOSTDINC-ISYSTEM-AFTER-NOT: "-internal-isystem" "[[RESOURCE_DIR]]{{(/|\\\\)}}include"
+// CHECK-NOSTDINC-ISYSTEM-AFTER: "-internal-isystem" "Windows Kits{{[/\\]}}10{{[/\\]}}Include{{[/\\]}}10.0.10586.0{{[/\\]}}ucrt"