Index: cmake/config-ix.cmake
===================================================================
--- cmake/config-ix.cmake
+++ cmake/config-ix.cmake
@@ -56,6 +56,7 @@
 if( NOT PURE_WINDOWS )
   check_include_file(pthread.h HAVE_PTHREAD_H)
 endif()
+check_include_file(pwd.h HAVE_PWD_H)
 check_include_file(signal.h HAVE_SIGNAL_H)
 check_include_file(stdint.h HAVE_STDINT_H)
 check_include_file(sys/dir.h HAVE_SYS_DIR_H)
Index: include/llvm/Config/config.h.cmake
===================================================================
--- include/llvm/Config/config.h.cmake
+++ include/llvm/Config/config.h.cmake
@@ -232,6 +232,9 @@
 /* Have pthread_rwlock_init */
 #cmakedefine HAVE_PTHREAD_RWLOCK_INIT ${HAVE_PTHREAD_RWLOCK_INIT}
 
+/* Define to 1 if you have the <pwd.h> header file. */
+#cmakedefine HAVE_PWD_H ${HAVE_PWD_H}
+
 /* Define to 1 if srand48/lrand48/drand48 exist in <stdlib.h> */
 #cmakedefine HAVE_RAND48 ${HAVE_RAND48}
 
Index: lib/Support/Unix/Path.inc
===================================================================
--- lib/Support/Unix/Path.inc
+++ lib/Support/Unix/Path.inc
@@ -28,6 +28,9 @@
 #ifdef HAVE_SYS_MMAN_H
 #include <sys/mman.h>
 #endif
+#ifdef HAVE_PWD_H
+#include <pwd.h>
+#endif
 #if HAVE_DIRENT_H
 # include <dirent.h>
 # define NAMLEN(dirent) strlen((dirent)->d_name)
@@ -550,13 +553,42 @@
 
 namespace path {
 
-bool home_directory(SmallVectorImpl<char> &result) {
+static bool getHomeDirFromPasswd(SmallVectorImpl<char> &Result) {
+  static const size_t InitialBufSize = 1024;
+  SmallString<InitialBufSize> Buf;
+  Buf.reserve(InitialBufSize);
+  Buf.set_size(Buf.capacity());
+
+  ::passwd Passwd;
+  ::passwd *PasswdResult = nullptr;
+  int Err = 0;
+  while ((Err = ::getpwuid_r(::getuid(), &Passwd, Buf.data(), Buf.size(),
+                             &PasswdResult)) == ERANGE) {
+    Buf.reserve(Buf.size() * 2);
+    Buf.set_size(Buf.capacity());
+  }
+
+  if (!Err) {
+    assert(PasswdResult == &Passwd && "getpwuid_r does strange things");
+    auto Dir = Passwd.pw_dir;
+    Result.clear();
+    Result.append(Dir, Dir + strlen(Dir));
+    return true;
+  }
+
+  return false;
+}
+
+bool home_directory(SmallVectorImpl<char> &Result) {
   if (char *RequestedDir = getenv("HOME")) {
-    result.clear();
-    result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
+    Result.clear();
+    Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
     return true;
   }
 
+  if (getHomeDirFromPasswd(Result))
+    return true;
+
   return false;
 }
 
Index: unittests/Support/Path.cpp
===================================================================
--- unittests/Support/Path.cpp
+++ unittests/Support/Path.cpp
@@ -41,6 +41,34 @@
 
 namespace {
 
+class EnvVarModifier {
+  const char *Name;
+  const char *OrigValue;
+  const char *Value;
+
+public:
+  EnvVarModifier(const char *Name, const char *Value)
+      : Name(Name), Value(Value) {
+    OrigValue = std::getenv(Name);
+    if (std::strlen(Value))
+      ::setenv(Name, Value, 1);
+    else
+      ::unsetenv(Name);
+  }
+
+  ~EnvVarModifier() { ::setenv(Name, OrigValue, 1); }
+
+  EnvVarModifier(const EnvVarModifier &) = delete;
+  EnvVarModifier &operator=(const EnvVarModifier &) = delete;
+
+  const char *getValue() const { return Value; }
+
+  void setValue(const char *Value) {
+    if (::setenv(Name, Value, 1) == 0)
+      this->Value = Value;
+  }
+};
+
 TEST(is_separator, Works) {
   EXPECT_TRUE(path::is_separator('/'));
   EXPECT_FALSE(path::is_separator('\0'));
@@ -322,6 +350,19 @@
   }
 }
 
+#ifdef LLVM_ON_UNIX
+TEST(Support, HomeDirectoryOnUnix) {
+  SmallString<200> HomeDir;
+
+  if (path::home_directory(HomeDir)) {
+    // If home_directory returns anything, check again without $HOME set.
+    // That will test the part of implementation that uses getpwuid().
+    EnvVarModifier HomeVar{"HOME", ""};
+    EXPECT_TRUE(path::home_directory(HomeDir));
+  }
+}
+#endif
+
 TEST(Support, UserCacheDirectory) {
   SmallString<13> CacheDir;
   SmallString<20> CacheDir2;