Driver: introduce and use `-isystem-after` for cross-windows

This mirrors the many other -i*after options to insert a new system search
directory at the end of the search path.  This makes it possible to actually
inject a search path after the resource dir.  This option is similar in spirit
to the /imsvc option in the clang-cl driver.  This is needed to properly use the
driver for Windows targets where the clang headers wrap some of the system
headers.

This concept is actually useful on other targets (e.g. Linux) and would be
really easy to support on the core toolchain.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@273016 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 5c240f36b487593a554eaba7b1d5aeda028209aa..00523666de1d38d2791def74f24a8874d0b61f26 100644 (file)
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -1277,6 +1277,9 @@ def isysroot : JoinedOrSeparate<["-"], "isysroot">, Group<clang_i_Group>, Flags<
 def isystem : JoinedOrSeparate<["-"], "isystem">, Group<clang_i_Group>,
   Flags<[CC1Option]>,
   HelpText<"Add directory to SYSTEM include search path">, MetaVarName<"<directory>">;
+def isystem_after : JoinedOrSeparate<["-"], "isystem-after">,
+  Group<clang_i_Group>, Flags<[DriverOption]>, MetaVarName<"<directory>">,
+  HelpText<"Add directory to end of the SYSTEM include search path">;
 def iwithprefixbefore : JoinedOrSeparate<["-"], "iwithprefixbefore">, Group<clang_i_Group>,
   HelpText<"Set directory to include search path with prefix">, MetaVarName<"<dir>">,
   Flags<[CC1Option]>;

diff --git a/lib/Driver/CrossWindowsToolChain.cpp b/lib/Driver/CrossWindowsToolChain.cpp
index 57bf896359871d276cae4ea308d5a65b53eac3b3..4ebbc533232f52347e4ba1771148296b781df560 100644 (file)
--- a/lib/Driver/CrossWindowsToolChain.cpp
+++ b/lib/Driver/CrossWindowsToolChain.cpp
@@ -62,6 +62,8 @@ AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,
     llvm::sys::path::append(ResourceDir, "include");
     addSystemInclude(DriverArgs, CC1Args, ResourceDir);
   }
+  for (const auto &P : DriverArgs.getAllArgValues(options::OPT_isystem_after))
+    addSystemInclude(DriverArgs, CC1Args, P);
   addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/include");
 }
 

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 62738e66990f50f8ccab1ad9336c37792f1d9d92..b911c17e2bce2fbb7406ab3f2f4619685f44c06f 100644 (file)
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -502,6 +502,13 @@ void Clang::AddPreprocessingOptions(Compilation &C, const JobAction &JA,
                                                        << A->getAsString(Args);
         }
       }
+    } else if (A->getOption().matches(options::OPT_isystem_after)) {
+      // Handling of paths which must come late.  These entries are handled by
+      // the toolchain itself after the resource dir is inserted in the right
+      // search order.
+      // Do not claim the argument so that the use of the argument does not
+      // silently go unnoticed on toolchains which do not honour the option.
+      continue;
     }
 
     // Not translated, render as usual.

diff --git a/test/Driver/windows-cross.c b/test/Driver/windows-cross.c
index 083e4b00368c53decf663d75cf47e69585142fb3..0b08762a4af72961aca06a08602887e4d8f7be02 100644 (file)
--- a/test/Driver/windows-cross.c
+++ b/test/Driver/windows-cross.c
@@ -67,3 +67,10 @@
 // CHECK-SANITIZE-TSAN: error: unsupported argument 'tsan' to option 'fsanitize='
 // CHECK-SANITIZE-TSAN-NOT: "-fsanitize={{.*}}"
 
+// 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: "-internal-isystem" "{{.*}}/clang/3.9.0/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"
+