[Driver] Fix finding multilib gcc install on Gentoo (with gcc-config)

[mgorny]

Summary

Fix the gcc-config code to support multilib gcc installs properly. This
solves two problems: -mx32 using the 64-bit gcc directory (due to matching
installation triple), and -m32 not respecting gcc-config at all (due to
mismatched installation triple).

In order to fix the former issue, split the multilib scan out of
Generic_GCC::GCCInstallationDetector::ScanLibDirForGCCTriple() (the code
is otherwise unchanged), and call it for each installation found via
gcc-config.

In order to fix the latter issue, split the gcc-config processing out of
Generic_GCC::GCCInstallationDetector::init() and repeat it for all
triples, including extra and biarch triples. The only change
in the gcc-config code itself is adding the call to multilib scan.

Convert the gentoo_linux_gcc_multi_version_tree test input to multilib
x86_64+32+x32 install, and add appropriate tests to linux-header-search
and linux-ld.

[mgorny]

Ping.

[rengolin]

I don't know enough about x86_64's ABI to have a solid opinion.

[bkramer]

I believe this is fine.

[mgorny]

Thanks for the review. Committed now.

lib/Driver/ToolChains.h

private:
     static void
     CollectLibDirsAndTriples(const llvm::Triple &TargetTriple,
                              const llvm::Triple &BiarchTriple,
                              SmallVectorImpl<StringRef> &LibDirs,
                              SmallVectorImpl<StringRef> &TripleAliases,
                              SmallVectorImpl<StringRef> &BiarchLibDirs,
                              SmallVectorImpl<StringRef> &BiarchTripleAliases);
 
+    bool ScanGCCForMultilibs(const llvm::Triple &TargetTriple,
+                             const llvm::opt::ArgList &Args,
+                             StringRef Path,
+                             bool NeedsBiarchSuffix = false);
+
     void ScanLibDirForGCCTriple(const llvm::Triple &TargetArch,
                                 const llvm::opt::ArgList &Args,
                                 const std::string &LibDir,
                                 StringRef CandidateTriple,
                                 bool NeedsBiarchSuffix = false);
 
     void scanLibDirForGCCTripleSolaris(const llvm::Triple &TargetArch,
                                        const llvm::opt::ArgList &Args,
                                        const std::string &LibDir,
                                        StringRef CandidateTriple,
                                        bool NeedsBiarchSuffix = false);
+
+    bool ScanGentooGccConfig(const llvm::Triple &TargetTriple,
+                             const llvm::opt::ArgList &Args,
+                             StringRef CandidateTriple,
+                             bool NeedsBiarchSuffix = false);
   };
 
 protected:
   GCCInstallationDetector GCCInstallation;
   CudaInstallationDetector CudaInstallation;
 
 public:
   Generic_GCC(const Driver &D, const llvm::Triple &Triple,

lib/Driver/ToolChains.cpp

if (GCCToolchainDir != "") {
     }
   }
 
   // Try to respect gcc-config on Gentoo. However, do that only
   // if --gcc-toolchain is not provided or equal to the Gentoo install
   // in /usr. This avoids accidentally enforcing the system GCC version
   // when using a custom toolchain.
   if (GCCToolchainDir == "" || GCCToolchainDir == D.SysRoot + "/usr") {
-    for (StringRef CandidateTriple : CandidateTripleAliases) {
-      llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
-          D.getVFS().getBufferForFile(D.SysRoot + "/etc/env.d/gcc/config-" +
-                                      CandidateTriple.str());
-      if (File) {
-        SmallVector<StringRef, 2> Lines;
-        File.get()->getBuffer().split(Lines, "\n");
-        for (StringRef Line : Lines) {
-          // CURRENT=triple-version
-          if (Line.consume_front("CURRENT=")) {
-            const std::pair<StringRef, StringRef> ActiveVersion =
-              Line.rsplit('-');
-            // Note: Strictly speaking, we should be reading
-            // /etc/env.d/gcc/${CURRENT} now. However, the file doesn't
-            // contain anything new or especially useful to us.
-            const std::string GentooPath = D.SysRoot + "/usr/lib/gcc/" +
-                                           ActiveVersion.first.str() + "/" +
-                                           ActiveVersion.second.str();
-            if (D.getVFS().exists(GentooPath + "/crtbegin.o")) {
-              Version = GCCVersion::Parse(ActiveVersion.second);
-              GCCInstallPath = GentooPath;
-              GCCParentLibPath = GentooPath + "/../../..";
-              GCCTriple.setTriple(ActiveVersion.first);
-              IsValid = true;
-              return;
-            }
-          }
-        }
-      }
+    for (StringRef CandidateTriple : ExtraTripleAliases) {
+      if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple))
+    for (StringRef CandidateTriple : CandidateTripleAliases) {
+      if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple))
+        return;
+    for (StringRef CandidateTriple : CandidateBiarchTripleAliases) {
+      if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple, true))
+        return;
     }
   }
 
   // Loop over the various components which exist and select the best GCC
   // installation available. GCC installs are ranked by version number.
   Version = GCCVersion::Parse("0.0.0");
   for (const std::string &Prefix : Prefixes) {
     if (!D.getVFS().exists(Prefix))
for (vfs::directory_iterator LI = D.getVFS().dir_begin(LibDir, EC), LE;
 
     GCCInstallPath += "/" + Version.Text;
     GCCParentLibPath = GCCInstallPath + "/../../../../";
 
     IsValid = true;
   }
 }
 
+bool Generic_GCC::GCCInstallationDetector::ScanGCCForMultilibs(
+    const llvm::Triple &TargetTriple, const ArgList &Args,
+    StringRef Path, bool NeedsBiarchSuffix) {
+  llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
+  DetectedMultilibs Detected;
+
+  // Android standalone toolchain could have multilibs for ARM and Thumb.
+  // Debian mips multilibs behave more like the rest of the biarch ones,
+  // so handle them there
+  if (isArmOrThumbArch(TargetArch) && TargetTriple.isAndroid()) {
+    // It should also work without multilibs in a simplified toolchain.
+    findAndroidArmMultilibs(D, TargetTriple, Path, Args, Detected);
+  } else if (isMipsArch(TargetArch)) {
+    if (!findMIPSMultilibs(D, TargetTriple, Path, Args, Detected))
+      return false;
+  } else if (!findBiarchMultilibs(D, TargetTriple, Path, Args,
+                                  NeedsBiarchSuffix, Detected)) {
+    return false;
+  }
+
+  Multilibs = Detected.Multilibs;
+  SelectedMultilib = Detected.SelectedMultilib;
+  BiarchSibling = Detected.BiarchSibling;
+
+  return true;
+}
+
 void Generic_GCC::GCCInstallationDetector::ScanLibDirForGCCTriple(
     const llvm::Triple &TargetTriple, const ArgList &Args,
     const std::string &LibDir, StringRef CandidateTriple,
     bool NeedsBiarchSuffix) {
   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
   // There are various different suffixes involving the triple we
   // check for. We also record what is necessary to walk from each back
   // up to the lib directory. Specifically, the number of "up" steps
for (vfs::directory_iterator
       if (CandidateVersion.Major != -1) // Filter obviously bad entries.
         if (!CandidateGCCInstallPaths.insert(LI->getName()).second)
           continue; // Saw this path before; no need to look at it again.
       if (CandidateVersion.isOlderThan(4, 1, 1))
         continue;
       if (CandidateVersion <= Version)
         continue;
 
-      DetectedMultilibs Detected;
-
-      // Android standalone toolchain could have multilibs for ARM and Thumb.
-      // Debian mips multilibs behave more like the rest of the biarch ones,
-      // so handle them there
-      if (isArmOrThumbArch(TargetArch) && TargetTriple.isAndroid()) {
-        // It should also work without multilibs in a simplified toolchain.
-        findAndroidArmMultilibs(D, TargetTriple, LI->getName(), Args, Detected);
-      } else if (isMipsArch(TargetArch)) {
-        if (!findMIPSMultilibs(D, TargetTriple, LI->getName(), Args, Detected))
-          continue;
-      } else if (!findBiarchMultilibs(D, TargetTriple, LI->getName(), Args,
-                                      NeedsBiarchSuffix, Detected)) {
+      if (!ScanGCCForMultilibs(TargetTriple, Args, LI->getName(),
+                               NeedsBiarchSuffix))
         continue;
-      }
 
-      Multilibs = Detected.Multilibs;
-      SelectedMultilib = Detected.SelectedMultilib;
-      BiarchSibling = Detected.BiarchSibling;
       Version = CandidateVersion;
       GCCTriple.setTriple(CandidateTriple);
       // FIXME: We hack together the directory name here instead of
       // using LI to ensure stable path separators across Windows and
       // Linux.
       GCCInstallPath =
           LibDir + LibAndInstallSuffixes[i][0] + "/" + VersionText.str();
       GCCParentLibPath = GCCInstallPath + LibAndInstallSuffixes[i][1];
       IsValid = true;
     }
   }
 }
 
+bool Generic_GCC::GCCInstallationDetector::ScanGentooGccConfig(
+    const llvm::Triple &TargetTriple, const ArgList &Args,
+    StringRef CandidateTriple, bool NeedsBiarchSuffix) {
+  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
+      D.getVFS().getBufferForFile(D.SysRoot + "/etc/env.d/gcc/config-" +
+                                  CandidateTriple.str());
+  if (File) {
+    SmallVector<StringRef, 2> Lines;
+    File.get()->getBuffer().split(Lines, "\n");
+    for (StringRef Line : Lines) {
+      // CURRENT=triple-version
+      if (Line.consume_front("CURRENT=")) {
+        const std::pair<StringRef, StringRef> ActiveVersion =
+          Line.rsplit('-');
+        // Note: Strictly speaking, we should be reading
+        // /etc/env.d/gcc/${CURRENT} now. However, the file doesn't
+        // contain anything new or especially useful to us.
+        const std::string GentooPath = D.SysRoot + "/usr/lib/gcc/" +
+                                       ActiveVersion.first.str() + "/" +
+                                       ActiveVersion.second.str();
+        if (D.getVFS().exists(GentooPath + "/crtbegin.o")) {
+          if (!ScanGCCForMultilibs(TargetTriple, Args, GentooPath,
+                                   NeedsBiarchSuffix))
+            return false;
+
+          Version = GCCVersion::Parse(ActiveVersion.second);
+          GCCInstallPath = GentooPath;
+          GCCParentLibPath = GentooPath + "/../../..";
+          GCCTriple.setTriple(ActiveVersion.first);
+          IsValid = true;
+          return true;
+        }
+      }
+    }
+  }
+
+  return false;
+}
+
 Generic_GCC::Generic_GCC(const Driver &D, const llvm::Triple &Triple,
                          const ArgList &Args)
     : ToolChain(D, Triple, Args), GCCInstallation(D),
       CudaInstallation(D, Triple, Args) {
   getProgramPaths().push_back(getDriver().getInstalledDir());
   if (getDriver().getInstalledDir() != getDriver().Dir)
     getProgramPaths().push_back(getDriver().Dir);
 }

test/Driver/linux-header-search.cpp

 // (4.9.3) version over the newer (5.4.0) due to preference specified
 // in /etc/env.d/gcc/x86_64-pc-linux-gnu.
 // RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
 // RUN:     -target x86_64-unknown-linux-gnu -stdlib=libstdc++ \
 // RUN:     --sysroot=%S/Inputs/gentoo_linux_gcc_multi_version_tree \
 // RUN:     --gcc-toolchain="" \
 // RUN:   | FileCheck --check-prefix=CHECK-GENTOO-4-9-3 %s
 //
+// Test that gcc-config support does not break multilib.
+// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
+// RUN:     -target x86_64-unknown-linux-gnux32 -stdlib=libstdc++ \
+// RUN:     --sysroot=%S/Inputs/gentoo_linux_gcc_multi_version_tree \
+// RUN:     --gcc-toolchain="" \
+// RUN:   | FileCheck --check-prefix=CHECK-GENTOO-4-9-3-X32 %s
+// CHECK-GENTOO-4-9-3-X32: "{{.*}}clang{{.*}}" "-cc1"
+// CHECK-GENTOO-4-9-3-X32: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
+// CHECK-GENTOO-4-9-3-X32: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-GENTOO-4-9-3-X32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/include/g++-v4.9.3"
+// CHECK-GENTOO-4-9-3-X32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/include/g++-v4.9.3/x86_64-pc-linux-gnu/x32"
+// CHECK-GENTOO-4-9-3-X32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/include/g++-v4.9.3/backward"
+// CHECK-GENTOO-4-9-3-X32: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
+// CHECK-GENTOO-4-9-3-X32: "-internal-isystem" "[[RESOURCE_DIR]]{{/|\\\\}}include"
+// CHECK-GENTOO-4-9-3-X32: "-internal-externc-isystem" "[[SYSROOT]]/include"
+// CHECK-GENTOO-4-9-3-X32: "-internal-externc-isystem" "[[SYSROOT]]/usr/include"
+//
+// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
+// RUN:     -target i386-unknown-linux-gnu -stdlib=libstdc++ \
+// RUN:     --sysroot=%S/Inputs/gentoo_linux_gcc_multi_version_tree \
+// RUN:     --gcc-toolchain="" \
+// RUN:   | FileCheck --check-prefix=CHECK-GENTOO-4-9-3-32 %s
+// CHECK-GENTOO-4-9-3-32: "{{.*}}clang{{.*}}" "-cc1"
+// CHECK-GENTOO-4-9-3-32: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
+// CHECK-GENTOO-4-9-3-32: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-GENTOO-4-9-3-32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/include/g++-v4.9.3"
+// CHECK-GENTOO-4-9-3-32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/include/g++-v4.9.3/x86_64-pc-linux-gnu/32"
+// CHECK-GENTOO-4-9-3-32: "-internal-isystem" "[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/include/g++-v4.9.3/backward"
+// CHECK-GENTOO-4-9-3-32: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
+// CHECK-GENTOO-4-9-3-32: "-internal-isystem" "[[RESOURCE_DIR]]{{/|\\\\}}include"
+// CHECK-GENTOO-4-9-3-32: "-internal-externc-isystem" "[[SYSROOT]]/include"
+// CHECK-GENTOO-4-9-3-32: "-internal-externc-isystem" "[[SYSROOT]]/usr/include"
+//
 // Check header search on Debian 6 / MIPS64
 // RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
 // RUN:     -target mips64-unknown-linux-gnuabi64 -stdlib=libstdc++ \
 // RUN:     --sysroot=%S/Inputs/debian_6_mips64_tree \
 // RUN:     --gcc-toolchain="" \
 // RUN:   | FileCheck --check-prefix=CHECK-MIPS64-GNUABI %s
 // CHECK-MIPS64-GNUABI: "{{[^"]*}}clang{{[^"]*}}" "-cc1"
 // CHECK-MIPS64-GNUABI: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"

test/Driver/linux-ld.c

 // CHECK-MUSL-PPC:        "-dynamic-linker" "/lib/ld-musl-powerpc.so.1"
 // CHECK-MUSL-PPC64:      "-dynamic-linker" "/lib/ld-musl-powerpc64.so.1"
 // CHECK-MUSL-ARM:        "-dynamic-linker" "/lib/ld-musl-arm.so.1"
 // CHECK-MUSL-ARMHF:      "-dynamic-linker" "/lib/ld-musl-armhf.so.1"
 // CHECK-MUSL-ARMEB:      "-dynamic-linker" "/lib/ld-musl-armeb.so.1"
 // CHECK-MUSL-ARMEBHF:    "-dynamic-linker" "/lib/ld-musl-armebhf.so.1"
 // CHECK-MUSL-AARCH64:    "-dynamic-linker" "/lib/ld-musl-aarch64.so.1"
 // CHECK-MUSL-AARCH64_BE: "-dynamic-linker" "/lib/ld-musl-aarch64_be.so.1"
+
+// Check whether multilib gcc install works fine on Gentoo with gcc-config
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=x86_64-unknown-linux-gnu -rtlib=platform \
+// RUN:     --sysroot=%S/Inputs/gentoo_linux_gcc_multi_version_tree \
+// RUN:     --gcc-toolchain="" \
+// RUN:   | FileCheck --check-prefix=CHECK-LD-GENTOO %s
+// CHECK-LD-GENTOO-NOT: warning:
+// CHECK-LD-GENTOO: "{{.*}}ld{{(.exe)?}}" "--sysroot=[[SYSROOT:[^"]+]]"
+// CHECK-LD-GENTOO: "--eh-frame-hdr"
+// CHECK-LD-GENTOO: "-m" "elf_x86_64"
+// CHECK-LD-GENTOO: "-dynamic-linker"
+// CHECK-LD-GENTOO: "{{.*}}/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/crtbegin.o"
+// CHECK-LD-GENTOO: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3"
+// CHECK-LD-GENTOO: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/../../../../x86_64-pc-linux-gnu/lib"
+// CHECK-LD-GENTOO: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/../../.."
+// CHECK-LD-GENTOO: "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed"
+// CHECK-LD-GENTOO: "-lc"
+// CHECK-LD-GENTOO: "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed"
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=i686-unknown-linux-gnu -rtlib=platform \
+// RUN:     --sysroot=%S/Inputs/gentoo_linux_gcc_multi_version_tree \
+// RUN:     --gcc-toolchain="" \
+// RUN:   | FileCheck --check-prefix=CHECK-LD-GENTOO-32 %s
+// CHECK-LD-GENTOO-32-NOT: warning:
+// CHECK-LD-GENTOO-32: "{{.*}}ld{{(.exe)?}}" "--sysroot=[[SYSROOT:[^"]+]]"
+// CHECK-LD-GENTOO-32: "--eh-frame-hdr"
+// CHECK-LD-GENTOO-32: "-m" "elf_i386"
+// CHECK-LD-GENTOO-32: "-dynamic-linker"
+// CHECK-LD-GENTOO-32: "{{.*}}/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/32/crtbegin.o"
+// CHECK-LD-GENTOO-32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/32"
+// CHECK-LD-GENTOO-32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/../../../../x86_64-pc-linux-gnu/lib"
+// CHECK-LD-GENTOO-32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/../../.."
+// CHECK-LD-GENTOO-32: "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed"
+// CHECK-LD-GENTOO-32: "-lc"
+// CHECK-LD-GENTOO-32: "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed"
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=x86_64-unknown-linux-gnux32 -rtlib=platform \
+// RUN:     --sysroot=%S/Inputs/gentoo_linux_gcc_multi_version_tree \
+// RUN:     --gcc-toolchain="" \
+// RUN:   | FileCheck --check-prefix=CHECK-LD-GENTOO-X32 %s
+// CHECK-LD-GENTOO-X32-NOT: warning:
+// CHECK-LD-GENTOO-X32: "{{.*}}ld{{(.exe)?}}" "--sysroot=[[SYSROOT:[^"]+]]"
+// CHECK-LD-GENTOO-X32: "--eh-frame-hdr"
+// CHECK-LD-GENTOO-X32: "-m" "elf32_x86_64"
+// CHECK-LD-GENTOO-X32: "-dynamic-linker"
+// CHECK-LD-GENTOO-X32: "{{.*}}/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/x32/crtbegin.o"
+// CHECK-LD-GENTOO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/x32"
+// CHECK-LD-GENTOO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/../../../../x86_64-pc-linux-gnu/lib"
+// CHECK-LD-GENTOO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/../../.."
+// CHECK-LD-GENTOO-X32: "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed"
+// CHECK-LD-GENTOO-X32: "-lc"
+// CHECK-LD-GENTOO-X32: "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed"