Significantly fix Clang's header search for Ubuntu (and possibly other

modern Debian-based distributions) due to on-going multiarch madness.

It appears that when the multiarch heeader search support went into the
clang driver, it went in in a quite bad state. The order of includes
completely failed to match the order exhibited by GCC, and in a specific
case -- when the GCC triple and the multiarch triple don't match as with
i686-linux-gnu and i386-linux-gnu -- we would absolutely fail to find
the libstdc++ target-specific header files.

I assume that folks who have been using Clang on Ubuntu 32-bit systems
have been applying weird patches to hack around this. I can't imagine
how else it could have worked. This was originally reported by a 64-bit
operating system user who had a 32-bit crosscompiler installed. We tried
to use that rather than the bi-arch support of the 64-bit compiler, but
failed due to the triple differences.

I've corrected all the wrong orderings in the existing tests and added
a specific test for the multiarch triple strings that are different in
a significant way. This should significantly improve the usability of
Clang when checked out vanilla from upstream onto Ubuntu machines with
an i686 GCC installation for whatever reason.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216531 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index c7654b7ddba3785d8fd2b4701d20e5bc10377dde..9ea21b49478d9881a8454f6e02d88a3f6391ad58 100644 (file)
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -3345,32 +3345,39 @@ void Linux::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
   addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/include");
 }
 
-/// \brief Helper to add the three variant paths for a libstdc++ installation.
-/*static*/ bool Linux::addLibStdCXXIncludePaths(Twine Base, Twine TargetArchDir,
-                                                const ArgList &DriverArgs,
-                                                ArgStringList &CC1Args) {
-  if (!llvm::sys::fs::exists(Base))
-    return false;
-  addSystemInclude(DriverArgs, CC1Args, Base);
-  addSystemInclude(DriverArgs, CC1Args, Base + "/" + TargetArchDir);
-  addSystemInclude(DriverArgs, CC1Args, Base + "/backward");
-  return true;
-}
-
-/// \brief Helper to add an extra variant path for an (Ubuntu) multilib
-/// libstdc++ installation.
+/// \brief Helper to add the variant paths of a libstdc++ installation.
 /*static*/ bool Linux::addLibStdCXXIncludePaths(Twine Base, Twine Suffix,
-                                                Twine TargetArchDir,
+                                                StringRef GCCTriple,
+                                                StringRef GCCMultiarchTriple,
+                                                StringRef TargetMultiarchTriple,
                                                 Twine IncludeSuffix,
                                                 const ArgList &DriverArgs,
                                                 ArgStringList &CC1Args) {
-  if (!addLibStdCXXIncludePaths(Base + Suffix,
-                                TargetArchDir + IncludeSuffix,
-                                DriverArgs, CC1Args))
+  if (!llvm::sys::fs::exists(Base))
     return false;
 
-  addSystemInclude(DriverArgs, CC1Args, Base + "/" + TargetArchDir + Suffix
-                   + IncludeSuffix);
+  addSystemInclude(DriverArgs, CC1Args, Base + Suffix);
+
+  // The vanilla GCC layout of libstdc++ headers uses a triple subdirectory. If
+  // that path exists or we have neither a GCC nor target multiarch triple, use
+  // this vanilla search path.
+  if ((GCCMultiarchTriple.empty() && TargetMultiarchTriple.empty()) ||
+      llvm::sys::fs::exists(Base + Suffix + "/" + GCCTriple + IncludeSuffix)) {
+    addSystemInclude(DriverArgs, CC1Args,
+                     Base + Suffix + "/" + GCCTriple + IncludeSuffix);
+  } else {
+    // Otherwise try to use multiarch naming schemes which have normalized the
+    // triples and put the triple before the suffix.
+    //
+    // GCC surprisingly uses *both* the GCC triple with a multilib suffix and
+    // the target triple, so we support that here.
+    addSystemInclude(DriverArgs, CC1Args,
+                     Base + "/" + GCCMultiarchTriple + Suffix + IncludeSuffix);
+    addSystemInclude(DriverArgs, CC1Args,
+                     Base + "/" + TargetMultiarchTriple + Suffix);
+  }
+
+  addSystemInclude(DriverArgs, CC1Args, Base + Suffix + "/backward");
   return true;
 }
 
@@ -3414,13 +3421,21 @@ void Linux::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
   StringRef InstallDir = GCCInstallation.getInstallPath();
   StringRef TripleStr = GCCInstallation.getTriple().str();
   const Multilib &Multilib = GCCInstallation.getMultilib();
+  const std::string GCCMultiarchTriple =
+      getMultiarchTriple(GCCInstallation.getTriple(), getDriver().SysRoot);
+  const std::string TargetMultiarchTriple =
+      getMultiarchTriple(getTriple(), getDriver().SysRoot);
   const GCCVersion &Version = GCCInstallation.getVersion();
 
+  // The primary search for libstdc++ supports multiarch variants.
   if (addLibStdCXXIncludePaths(LibDir.str() + "/../include",
-                               "/c++/" + Version.Text, TripleStr,
+                               "/c++/" + Version.Text, TripleStr, GCCMultiarchTriple,
+                               TargetMultiarchTriple,
                                Multilib.includeSuffix(), DriverArgs, CC1Args))
     return;
 
+  // Otherwise, fall back on a bunch of options which don't use multiarch
+  // layouts for simplicity.
   const std::string LibStdCXXIncludePathCandidates[] = {
     // Gentoo is weird and places its headers inside the GCC install, so if the
     // first attempt to find the headers fails, try these patterns.
@@ -3435,9 +3450,10 @@ void Linux::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
   };
 
   for (const auto &IncludePath : LibStdCXXIncludePathCandidates) {
-    if (addLibStdCXXIncludePaths(IncludePath,
-                                 TripleStr + Multilib.includeSuffix(),
-                                 DriverArgs, CC1Args))
+    if (addLibStdCXXIncludePaths(IncludePath, /*Suffix*/ "", TripleStr,
+                                 /*GCCMultiarchTriple*/ "",
+                                 /*TargetMultiarchTriple*/ "",
+                                 Multilib.includeSuffix(), DriverArgs, CC1Args))
       break;
   }
 }

diff --git a/lib/Driver/ToolChains.h b/lib/Driver/ToolChains.h
index a3b20d66948c2b74246141173a8730af073b8b9f..2c7ce062c06b3df1700f3d15d864b9cd1e8e76f7 100644 (file)
--- a/lib/Driver/ToolChains.h
+++ b/lib/Driver/ToolChains.h
@@ -679,10 +679,10 @@ protected:
 
 private:
   static bool addLibStdCXXIncludePaths(Twine Base, Twine Suffix,
-                                       Twine TargetArchDir, Twine IncludeSuffix,
-                                       const llvm::opt::ArgList &DriverArgs,
-                                       llvm::opt::ArgStringList &CC1Args);
-  static bool addLibStdCXXIncludePaths(Twine Base, Twine TargetArchDir,
+                                       StringRef GCCTriple,
+                                       StringRef GCCMultiarchTriple,
+                                       StringRef TargetMultiarchTriple,
+                                       Twine IncludeSuffix,
                                        const llvm::opt::ArgList &DriverArgs,
                                        llvm::opt::ArgStringList &CC1Args);
 

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/lib/i386-linux-gnu/.keep b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/lib/i386-linux-gnu/.keep
new file mode 100644 (file)
index 0000000..e69de29

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/lib/x86_64-linux-gnu/.keep b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/lib/x86_64-linux-gnu/.keep
new file mode 100755 (executable)
index 0000000..e69de29

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/include/c++/4.8/backward/.keep b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/include/c++/4.8/backward/.keep
new file mode 100755 (executable)
index 0000000..e69de29

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/include/i386-linux-gnu/c++/4.8/.keep b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/include/i386-linux-gnu/c++/4.8/.keep
new file mode 100644 (file)
index 0000000..e69de29

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/include/x86_64-linux-gnu/c++/4.8/32/.keep b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/include/x86_64-linux-gnu/c++/4.8/32/.keep
new file mode 100755 (executable)
index 0000000..e69de29

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/gcc/i686-linux-gnu/4.8/crtbegin.o b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/gcc/i686-linux-gnu/4.8/crtbegin.o
new file mode 100644 (file)
index 0000000..e69de29

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/gcc/x86_64-linux-gnu/4.8/32/crtbegin.o b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/gcc/x86_64-linux-gnu/4.8/32/crtbegin.o
new file mode 100755 (executable)
index 0000000..e69de29

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/gcc/x86_64-linux-gnu/4.8/crtbegin.o b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/gcc/x86_64-linux-gnu/4.8/crtbegin.o
new file mode 100755 (executable)
index 0000000..e69de29

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/i386-linux-gnu/.keep b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/i386-linux-gnu/.keep
new file mode 100644 (file)
index 0000000..e69de29

diff --git a/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/x86_64-linux-gnu/.keep b/test/Driver/Inputs/ubuntu_14.04_multiarch_tree2/usr/lib/x86_64-linux-gnu/.keep
new file mode 100644 (file)
index 0000000..e69de29

diff --git a/test/Driver/linux-header-search.cpp b/test/Driver/linux-header-search.cpp
index 9635519ad0cb592ef341bea4ccfe37ae7a81aa87..309ece28db775df5830b87e7fcb15c404568eac1 100644 (file)
--- a/test/Driver/linux-header-search.cpp
+++ b/test/Driver/linux-header-search.cpp
@@ -46,8 +46,8 @@
 // CHECK-UBUNTU-13-04: "{{[^"]*}}clang{{[^"]*}}" "-cc1"
 // CHECK-UBUNTU-13-04: "-isysroot" "[[SYSROOT:[^"]+]]"
 // CHECK-UBUNTU-13-04: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7"
-// CHECK-UBUNTU-13-04: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/backward"
 // CHECK-UBUNTU-13-04: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/x86_64-linux-gnu/c++/4.7"
+// CHECK-UBUNTU-13-04: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/backward"
 // CHECK-UBUNTU-13-04: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
 // CHECK-UBUNTU-13-04: "-internal-isystem" "{{.*}}{{/|\\\\}}lib{{(64|32)?}}{{/|\\\\}}clang{{/|\\\\}}{{[0-9]\.[0-9]\.[0-9]}}{{/|\\\\}}include"
 // CHECK-UBUNTU-13-04: "-internal-externc-isystem" "[[SYSROOT]]/usr/include/x86_64-linux-gnu"
@@ -61,9 +61,8 @@
 // CHECK-UBUNTU-14-04: "{{[^"]*}}clang{{[^"]*}}" "-cc1"
 // CHECK-UBUNTU-14-04: "-isysroot" "[[SYSROOT:[^"]+]]"
 // CHECK-UBUNTU-14-04: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8"
-// CHECK-UBUNTU-14-04: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/x86_64-linux-gnu/x32"
-// CHECK-UBUNTU-14-04: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/backward"
 // CHECK-UBUNTU-14-04: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/x86_64-linux-gnu/c++/4.8/x32"
+// CHECK-UBUNTU-14-04: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/backward"
 // CHECK-UBUNTU-14-04: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
 // CHECK-UBUNTU-14-04: "-internal-isystem" "{{.*}}{{/|\\\\}}lib{{(64|x32)?}}{{/|\\\\}}clang{{/|\\\\}}{{[0-9]\.[0-9]\.[0-9]}}{{/|\\\\}}include"
 // CHECK-UBUNTU-14-04: "-internal-externc-isystem" "[[SYSROOT]]/usr/include/x86_64-linux-gnu"
@@ -77,8 +76,8 @@
 // CHECK-UBUNTU-13-04-CROSS: "{{[^"]*}}clang{{[^"]*}}" "-cc1"
 // CHECK-UBUNTU-13-04-CROSS: "-isysroot" "[[SYSROOT:[^"]+]]"
 // CHECK-UBUNTU-13-04-CROSS: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc-cross/arm-linux-gnueabihf/4.7/../../../../include/c++/4.7"
-// CHECK-UBUNTU-13-04-CROSS: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc-cross/arm-linux-gnueabihf/4.7/../../../../include/c++/4.7/backward"
 // CHECK-UBUNTU-13-04-CROSS: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc-cross/arm-linux-gnueabihf/4.7/../../../../include/arm-linux-gnueabihf/c++/4.7"
+// CHECK-UBUNTU-13-04-CROSS: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc-cross/arm-linux-gnueabihf/4.7/../../../../include/c++/4.7/backward"
 // CHECK-UBUNTU-13-04-CROSS: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
 // CHECK-UBUNTU-13-04-CROSS: "-internal-isystem" "{{.*}}{{/|\\\\}}lib{{(64|32)?}}{{/|\\\\}}clang{{/|\\\\}}{{[0-9]\.[0-9]\.[0-9]}}{{/|\\\\}}include"
 // CHECK-UBUNTU-13-04-CROSS: "-internal-externc-isystem" "[[SYSROOT]]/include"
@@ -93,9 +92,8 @@
 // CHECK-UBUNTU-13-04-M32: "-triple" "i386-unknown-linux-gnu"
 // CHECK-UBUNTU-13-04-M32: "-isysroot" "[[SYSROOT:[^"]+]]"
 // CHECK-UBUNTU-13-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7"
-// CHECK-UBUNTU-13-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/x86_64-linux-gnu/32"
-// CHECK-UBUNTU-13-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/backward"
 // CHECK-UBUNTU-13-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/x86_64-linux-gnu/c++/4.7/32"
+// CHECK-UBUNTU-13-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/backward"
 //
 // Test Ubuntu/Debian's Ubuntu 14.04 config variant, with -m32
 // and an empty 4.9 directory.
@@ -107,9 +105,22 @@
 // CHECK-UBUNTU-14-04-M32: "-triple" "i386-unknown-linux-gnu"
 // CHECK-UBUNTU-14-04-M32: "-isysroot" "[[SYSROOT:[^"]+]]"
 // CHECK-UBUNTU-14-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8"
-// CHECK-UBUNTU-14-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/x86_64-linux-gnu/32"
-// CHECK-UBUNTU-14-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/backward"
 // CHECK-UBUNTU-14-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/x86_64-linux-gnu/c++/4.8/32"
+// CHECK-UBUNTU-14-04-M32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/backward"
+//
+// Test Ubuntu/Debian's Ubuntu 14.04 with -m32 and an i686 cross compiler
+// installed rather than relying on multilib. Also happens to look like an
+// actual i686 Ubuntu system.
+// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
+// RUN:     -target x86_64-unknown-linux-gnu -m32 \
+// RUN:     --sysroot=%S/Inputs/ubuntu_14.04_multiarch_tree2 \
+// RUN:   | FileCheck --check-prefix=CHECK-UBUNTU-14-04-I686 %s
+// CHECK-UBUNTU-14-04-I686: "{{[^"]*}}clang{{[^"]*}}" "-cc1"
+// CHECK-UBUNTU-14-04-I686: "-triple" "i386-unknown-linux-gnu"
+// CHECK-UBUNTU-14-04-I686: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-UBUNTU-14-04-I686: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/i686-linux-gnu/4.8/../../../../include/c++/4.8"
+// CHECK-UBUNTU-14-04-I686: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/i686-linux-gnu/4.8/../../../../include/i386-linux-gnu/c++/4.8"
+// CHECK-UBUNTU-14-04-I686: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/i686-linux-gnu/4.8/../../../../include/c++/4.8/backward"
 //
 // Test Ubuntu/Debian's Ubuntu 14.04 for powerpc64le
 // RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
@@ -120,9 +131,8 @@
 // CHECK-UBUNTU-14-04-PPC64LE: "-triple" "powerpc64le-unknown-linux-gnu"
 // CHECK-UBUNTU-14-04-PPC64LE: "-isysroot" "[[SYSROOT:[^"]+]]"
 // CHECK-UBUNTU-14-04-PPC64LE: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc64le-linux-gnu/4.8/../../../../include/c++/4.8"
-// CHECK-UBUNTU-14-04-PPC64LE: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc64le-linux-gnu/4.8/../../../../include/c++/4.8/powerpc64le-linux-gnu"
-// CHECK-UBUNTU-14-04-PPC64LE: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc64le-linux-gnu/4.8/../../../../include/c++/4.8/backward"
 // CHECK-UBUNTU-14-04-PPC64LE: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc64le-linux-gnu/4.8/../../../../include/powerpc64le-linux-gnu/c++/4.8"
+// CHECK-UBUNTU-14-04-PPC64LE: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/powerpc64le-linux-gnu/4.8/../../../../include/c++/4.8/backward"
 // CHECK-UBUNTU-14-04-PPC64LE: "-internal-externc-isystem" "[[SYSROOT]]/usr/include/powerpc64le-linux-gnu"
 // CHECK-UBUNTU-14-04-PPC64LE: "-internal-externc-isystem" "[[SYSROOT]]/include"
 // CHECK-UBUNTU-14-04-PPC64LE: "-internal-externc-isystem" "[[SYSROOT]]/usr/include"