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.
llvm-svn: 216531
diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index c7654b7..9ea21b4 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -3345,32 +3345,39 @@
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,
+/// \brief Helper to add the variant paths of a libstdc++ installation.
+/*static*/ bool Linux::addLibStdCXXIncludePaths(Twine Base, Twine Suffix,
+ StringRef GCCTriple,
+ StringRef GCCMultiarchTriple,
+ StringRef TargetMultiarchTriple,
+ Twine IncludeSuffix,
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.
-/*static*/ bool Linux::addLibStdCXXIncludePaths(Twine Base, Twine Suffix,
- Twine TargetArchDir,
- Twine IncludeSuffix,
- const ArgList &DriverArgs,
- ArgStringList &CC1Args) {
- if (!addLibStdCXXIncludePaths(Base + Suffix,
- TargetArchDir + IncludeSuffix,
- DriverArgs, CC1Args))
- return false;
+ addSystemInclude(DriverArgs, CC1Args, Base + Suffix);
- addSystemInclude(DriverArgs, CC1Args, Base + "/" + TargetArchDir + Suffix
- + IncludeSuffix);
+ // 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 @@
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 @@
};
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;
}
}