clang: driver: Check sysroot for ldso path

when we build multilib the ldso has different paths than clangs defaults,
every distro kind of does that so OE is not the only one,
it happens especially on ppc64, where OE does not necessarily follow the
default path for the dynamic linker, therefore adjust it for OE. Check
for the default path, and if it isn't there, check /lib.

Upstream-Status: Pending
Signed-off-by: Dan McGregor <dan.mcgregor@usask.ca>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

Author: dankm

clang/lib/Driver/ToolChains/Linux.cpp

@@ -516,8 +516,12 @@ std::string Linux::getDynamicLinker(const ArgList &Args) const {
         Triple.getEnvironment() == llvm::Triple::GNUEABIHFT64 ||
         tools::arm::getARMFloatABI(*this, Args) == tools::arm::FloatABI::Hard;
 
-    LibDir = "lib";
     Loader = HF ? "ld-linux-armhf.so.3" : "ld-linux.so.3";
+    LibDir = "lib32";
+    if (!getVFS().exists(getDriver().SysRoot + "/" + LibDir + "/" + Loader) &&
+         getVFS().exists(getDriver().SysRoot + "/lib/" + Loader)) {
+        LibDir = "lib";
+    }
     break;
   }
   case llvm::Triple::loongarch32: {
@@ -571,11 +575,19 @@ std::string Linux::getDynamicLinker(const ArgList &Args) const {
     LibDir = "lib64";
     Loader =
         (tools::ppc::hasPPCAbiArg(Args, "elfv2")) ? "ld64.so.2" : "ld64.so.1";
+    if (!getVFS().exists(getDriver().SysRoot + "/" + LibDir + "/" + Loader) &&
+         getVFS().exists(getDriver().SysRoot + "/lib/" + Loader)) {
+        LibDir = "lib";
+    }
     break;
   case llvm::Triple::ppc64le:
     LibDir = "lib64";
     Loader =
         (tools::ppc::hasPPCAbiArg(Args, "elfv1")) ? "ld64.so.1" : "ld64.so.2";
+    if (!getVFS().exists(getDriver().SysRoot + "/" + LibDir + "/" + Loader) &&
+         getVFS().exists(getDriver().SysRoot + "/lib/" + Loader)) {
+        LibDir = "lib";
+    }
     break;
   case llvm::Triple::riscv32:
   case llvm::Triple::riscv64: {
@@ -593,6 +605,10 @@ std::string Linux::getDynamicLinker(const ArgList &Args) const {
   case llvm::Triple::sparcv9:
     LibDir = "lib64";
     Loader = "ld-linux.so.2";
+    if (!getVFS().exists(getDriver().SysRoot + "/" + LibDir + "/" + Loader) &&
+         getVFS().exists(getDriver().SysRoot + "/lib/" + Loader)) {
+        LibDir = "lib";
+    }
     break;
   case llvm::Triple::systemz:
     LibDir = "lib";
@@ -607,6 +623,10 @@ std::string Linux::getDynamicLinker(const ArgList &Args) const {
 
     LibDir = X32 ? "libx32" : "lib64";
     Loader = X32 ? "ld-linux-x32.so.2" : "ld-linux-x86-64.so.2";
+    if (!getVFS().exists(getDriver().SysRoot + "/" + LibDir + "/" + Loader) &&
+         getVFS().exists(getDriver().SysRoot + "/lib/" + Loader)) {
+        LibDir = "lib";
+    }
     break;
   }
   case llvm::Triple::ve: