Support g++ headers in include/g++

[greened]

Summary

Cray's gcc installation puts C++ headers in PREFIX/include/g++ without indicating a gcc version at all. Typically this is because the version is encoded somewhere in PREFIX.

[rsmith]

This needs a test.

lib/Driver/ToolChains/Linux.cpp

927–928 ↗

(On Diff #171316)

It'd be useful to say who this "some" is, so we can check whether this is still a valid concern in the future.

[greened]

lib/Driver/ToolChains/Linux.cpp

927–928 ↗

(On Diff #171316)

I will try to find out where we got the package from.

[greened]

Explain that Cray packages gcc such that headers are in include/g++.

[rsmith]

Looks good with an accompanying test. (You can probably copy whatever was added for the FreeScale line above.)

[greened]

Oops, I didn't realize this hadn't been formally accepted yet. Still learning the Phab process. Let me know if you want it reverted for a formal accept.

[rsmith]

In D53770#1297646, @greened wrote:

Oops, I didn't realize this hadn't been formally accepted yet. Still learning the Phab process. Let me know if you want it reverted for a formal accept.

No, this is fine.

cfe/trunk/lib/Driver/ToolChains/Linux.cpp

const std::string LibStdCXXIncludePathCandidates[] = {
       InstallDir.str() + "/include/g++-v" + Version.MajorStr + "." +
           Version.MinorStr,
       InstallDir.str() + "/include/g++-v" + Version.MajorStr,
       // Android standalone toolchain has C++ headers in yet another place.
       LibDir.str() + "/../" + TripleStr.str() + "/include/c++/" + Version.Text,
       // Freescale SDK C++ headers are directly in <sysroot>/usr/include/c++,
       // without a subdirectory corresponding to the gcc version.
       LibDir.str() + "/../include/c++",
+      // Cray's gcc installation puts headers under "g++" without a
+      // version suffix.
+      LibDir.str() + "/../include/g++",
   };
 
   for (const auto &IncludePath : LibStdCXXIncludePathCandidates) {
     if (addLibStdCXXIncludePaths(IncludePath, /*Suffix*/ "", TripleStr,
                                  /*GCCMultiarchTriple*/ "",
                                  /*TargetMultiarchTriple*/ "",
                                  Multilib.includeSuffix(), DriverArgs, CC1Args))
       break;

cfe/trunk/test/Driver/linux-header-search.cpp

 // RUN:     --sysroot=%S/Inputs/openembedded_aarch64_linux_tree \
 // RUN:     --gcc-toolchain="" \
 // RUN:   | FileCheck --check-prefix=CHECK-OE-AARCH64 %s
 
 // CHECK-OE-AARCH64: "{{[^"]*}}clang{{[^"]*}}" "-cc1"
 // CHECK-OE-AARCH64: "-isysroot" "[[SYSROOT:[^"]+]]"
 // CHECK-OE-AARCH64: "-internal-isystem" "[[SYSROOT]]/usr/lib64/aarch64-oe-linux/6.3.0/../../../include/c++/6.3.0"
 // CHECK-OE-AARCH64: "-internal-isystem" "[[SYSROOT]]/usr/lib64/aarch64-oe-linux/6.3.0/../../../include/c++/6.3.0/backward"
+
+// Check header search with Cray's gcc package.
+// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
+// RUN:     -target x86_64-unknown-linux-gnu -stdlib=libstdc++ \
+// RUN:     --sysroot=%S/Inputs/cray_suse_gcc_tree \
+// RUN:     --gcc-toolchain="%S/Inputs/cray_suse_gcc_tree/opt/gcc/8.2.0/snos" \
+// RUN:   | FileCheck --check-prefix=CHECK-CRAY-X86 %s
+
+// CHECK-CRAY-X86: "{{[^"]*}}clang{{[^"]*}}" "-cc1"
+// CHECK-CRAY-X86: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-CRAY-X86: "-internal-isystem" "[[SYSROOT]]/opt/gcc/8.2.0/snos/lib/gcc/x86_64-suse-linux/8.2.0/../../../../include/g++"
+// CHECK-CRAY-X86: "-internal-isystem" "[[SYSROOT]]/opt/gcc/8.2.0/snos/lib/gcc/x86_64-suse-linux/8.2.0/../../../../include/g++/backward"