[Driver] Use the per-API level Android library directories.

Summary:
Android sysroots contain libraries for each OS version, as well as a
handful of unversioned libraries in the typical multiarch directory.

Reviewers: srhines, eugenis, george.burgess.iv

Reviewed By: eugenis

Subscribers: javed.absar, cfe-commits

Differential Revision: https://reviews.llvm.org/D45290

llvm-svn: 330213

1 files changed, 16 insertions, 0 deletions

diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
index 5473be2c1e7..e584fcd6b08 100644
--- a/clang/lib/Driver/ToolChains/Linux.cpp
+++ b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -22,6 +22,7 @@
 #include "llvm/Option/ArgList.h"
 #include "llvm/ProfileData/InstrProf.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/ScopedPrinter.h"
 #include <system_error>
 
 using namespace clang::driver;
@@ -350,6 +351,21 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
 
   addPathIfExists(D, SysRoot + "/lib/" + MultiarchTriple, Paths);
   addPathIfExists(D, SysRoot + "/lib/../" + OSLibDir, Paths);
+
+  if (IsAndroid) {
+    // Android sysroots contain a library directory for each supported OS
+    // version as well as some unversioned libraries in the usual multiarch
+    // directory.
+    unsigned Major;
+    unsigned Minor;
+    unsigned Micro;
+    Triple.getEnvironmentVersion(Major, Minor, Micro);
+    addPathIfExists(D,
+                    SysRoot + "/usr/lib/" + MultiarchTriple + "/" +
+                        llvm::to_string(Major),
+                    Paths);
+  }
+
   addPathIfExists(D, SysRoot + "/usr/lib/" + MultiarchTriple, Paths);
   addPathIfExists(D, SysRoot + "/usr/lib/../" + OSLibDir, Paths);
   if (IsRISCV) {