A follow-up to r151482 which added support for powerpc and powerpc64
Debian multiarch libraries, this should in theory add support for those
platform's header search rules. I don't have a system to check this
with, so review appreciated. I've added the corresponding tests
referring to the debian multiarch tree.

We are starting to have a relatively completely tested Linux platform
for header search and library search, with several interesting
peculiarities. We should point people at the debian_multiarch_tree when
suggesting new tests. Folks with Debian systems that can check this for
correctness, it would be much appreciated. The missing chunks I know of
are testing bi-arch peudo-cross-compiling toolchains betwen 32-bit and
64-bit variants of platforms, and the MIPS and ARM Debian toolchains.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151484 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index 20b2842..14c87d8 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -2180,6 +2180,12 @@
   const StringRef MIPSELMultiarchIncludeDirs[] = {
     "/usr/include/mipsel-linux-gnu"
   };
+  const StringRef PPCMultiarchIncludeDirs[] = {
+    "/usr/include/powerpc-linux-gnu"
+  };
+  const StringRef PPC64MultiarchIncludeDirs[] = {
+    "/usr/include/powerpc64-linux-gnu"
+  };
   ArrayRef<StringRef> MultiarchIncludeDirs;
   if (getTriple().getArch() == llvm::Triple::x86_64) {
     MultiarchIncludeDirs = X86_64MultiarchIncludeDirs;
@@ -2191,6 +2197,10 @@
     MultiarchIncludeDirs = MIPSMultiarchIncludeDirs;
   } else if (getTriple().getArch() == llvm::Triple::mipsel) {
     MultiarchIncludeDirs = MIPSELMultiarchIncludeDirs;
+  } else if (getTriple().getArch() == llvm::Triple::ppc) {
+    MultiarchIncludeDirs = PPCMultiarchIncludeDirs;
+  } else if (getTriple().getArch() == llvm::Triple::ppc64) {
+    MultiarchIncludeDirs = PPC64MultiarchIncludeDirs;
   }
   for (ArrayRef<StringRef>::iterator I = MultiarchIncludeDirs.begin(),
                                      E = MultiarchIncludeDirs.end();
diff --git a/test/Driver/linux-header-search.cpp b/test/Driver/linux-header-search.cpp
index f5e5f2b..1f8c7c9 100644
--- a/test/Driver/linux-header-search.cpp
+++ b/test/Driver/linux-header-search.cpp
@@ -15,3 +15,61 @@
 // CHECK-UBUNTU-11-04: "-internal-isystem" "{{.*}}/lib{{(64|32)?}}/clang/{{[0-9]\.[0-9]}}/include"
 // CHECK-UBUNTU-11-04: "-internal-externc-isystem" "[[SYSROOT]]/include"
 // CHECK-UBUNTU-11-04: "-internal-externc-isystem" "[[SYSROOT]]/usr/include"
+//
+// Thoroughly exercise the Debian multiarch environment.
+// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
+// RUN:     -target i686-linux-gnu \
+// RUN:     --sysroot=%S/Inputs/debian_multiarch_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-DEBIAN-X86 %s
+// CHECK-DEBIAN-X86: "{{.*}}clang{{(.exe)?}}" "-cc1"
+// CHECK-DEBIAN-X86: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-DEBIAN-X86: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/i686-linux-gnu/4.5/../../../../include/c++/4.5"
+// CHECK-DEBIAN-X86: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/i686-linux-gnu/4.5/../../../../include/c++/4.5/i686-linux-gnu"
+// CHECK-DEBIAN-X86: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/i686-linux-gnu/4.5/../../../../include/c++/4.5/backward"
+// CHECK-DEBIAN-X86: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
+// CHECK-DEBIAN-X86: "-internal-isystem" "{{.*}}/lib{{(64|32)?}}/clang/{{[0-9]\.[0-9]}}/include"
+// CHECK-DEBIAN-X86: "-internal-externc-isystem" "[[SYSROOT]]/usr/include/i386-linux-gnu"
+// CHECK-DEBIAN-X86: "-internal-externc-isystem" "[[SYSROOT]]/include"
+// CHECK-DEBIAN-X86: "-internal-externc-isystem" "[[SYSROOT]]/usr/include"
+// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
+// RUN:     -target x86_64-linux-gnu \
+// RUN:     --sysroot=%S/Inputs/debian_multiarch_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-DEBIAN-X86-64 %s
+// CHECK-DEBIAN-X86-64: "{{.*}}clang{{(.exe)?}}" "-cc1"
+// CHECK-DEBIAN-X86-64: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-DEBIAN-X86-64: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.5/../../../../include/c++/4.5"
+// CHECK-DEBIAN-X86-64: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.5/../../../../include/c++/4.5/x86_64-linux-gnu"
+// CHECK-DEBIAN-X86-64: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.5/../../../../include/c++/4.5/backward"
+// CHECK-DEBIAN-X86-64: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
+// CHECK-DEBIAN-X86-64: "-internal-isystem" "{{.*}}/lib{{(64|32)?}}/clang/{{[0-9]\.[0-9]}}/include"
+// CHECK-DEBIAN-X86-64: "-internal-externc-isystem" "[[SYSROOT]]/usr/include/x86_64-linux-gnu"
+// CHECK-DEBIAN-X86-64: "-internal-externc-isystem" "[[SYSROOT]]/include"
+// CHECK-DEBIAN-X86-64: "-internal-externc-isystem" "[[SYSROOT]]/usr/include"
+// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
+// RUN:     -target powerpc-linux-gnu \
+// RUN:     --sysroot=%S/Inputs/debian_multiarch_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-DEBIAN-PPC %s
+// CHECK-DEBIAN-PPC: "{{.*}}clang{{(.exe)?}}" "-cc1"
+// CHECK-DEBIAN-PPC: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-DEBIAN-PPC: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc-linux-gnu/4.5/../../../../include/c++/4.5"
+// CHECK-DEBIAN-PPC: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc-linux-gnu/4.5/../../../../include/c++/4.5/powerpc-linux-gnu"
+// CHECK-DEBIAN-PPC: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc-linux-gnu/4.5/../../../../include/c++/4.5/backward"
+// CHECK-DEBIAN-PPC: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
+// CHECK-DEBIAN-PPC: "-internal-isystem" "{{.*}}/lib{{(64|32)?}}/clang/{{[0-9]\.[0-9]}}/include"
+// CHECK-DEBIAN-PPC: "-internal-externc-isystem" "[[SYSROOT]]/usr/include/powerpc-linux-gnu"
+// CHECK-DEBIAN-PPC: "-internal-externc-isystem" "[[SYSROOT]]/include"
+// CHECK-DEBIAN-PPC: "-internal-externc-isystem" "[[SYSROOT]]/usr/include"
+// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
+// RUN:     -target powerpc64-linux-gnu \
+// RUN:     --sysroot=%S/Inputs/debian_multiarch_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-DEBIAN-PPC64 %s
+// CHECK-DEBIAN-PPC64: "{{.*}}clang{{(.exe)?}}" "-cc1"
+// CHECK-DEBIAN-PPC64: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-DEBIAN-PPC64: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc64-linux-gnu/4.5/../../../../include/c++/4.5"
+// CHECK-DEBIAN-PPC64: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc64-linux-gnu/4.5/../../../../include/c++/4.5/powerpc64-linux-gnu"
+// CHECK-DEBIAN-PPC64: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc64-linux-gnu/4.5/../../../../include/c++/4.5/backward"
+// CHECK-DEBIAN-PPC64: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
+// CHECK-DEBIAN-PPC64: "-internal-isystem" "{{.*}}/lib{{(64|32)?}}/clang/{{[0-9]\.[0-9]}}/include"
+// CHECK-DEBIAN-PPC64: "-internal-externc-isystem" "[[SYSROOT]]/usr/include/powerpc64-linux-gnu"
+// CHECK-DEBIAN-PPC64: "-internal-externc-isystem" "[[SYSROOT]]/include"
+// CHECK-DEBIAN-PPC64: "-internal-externc-isystem" "[[SYSROOT]]/usr/include"