Merge commit '72f0976c1b91c7ba50dce4d0ad0289dc14d37f81'

Conflicts:
	lib/Target/ARM/ARMISelDAGToDAG.cpp
	lib/Target/Mips/MipsISelLowering.cpp
	lib/Target/Mips/MipsSubtarget.cpp

1 files changed, 13 insertions, 4 deletions

diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
index f70e60d3f5..b82371a7b6 100644
--- a/lib/Support/Unix/Path.inc
+++ b/lib/Support/Unix/Path.inc
@@ -267,7 +267,8 @@ Path::GetCurrentDirectory() {
 }
 
 #if defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
-    defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__)
+    defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \
+    defined(__linux__) || defined(__CYGWIN__)
 static int
 test_dir(char buf[PATH_MAX], char ret[PATH_MAX],
     const char *dir, const char *bin)
@@ -345,9 +346,17 @@ Path Path::GetMainExecutable(const char *argv0, void *MainAddr) {
     return Path(exe_path);
 #elif defined(__linux__) || defined(__CYGWIN__)
   char exe_path[MAXPATHLEN];
-  ssize_t len = readlink("/proc/self/exe", exe_path, sizeof(exe_path));
-  if (len >= 0)
-    return Path(StringRef(exe_path, len));
+  StringRef aPath("/proc/self/exe");
+  if (sys::fs::exists(aPath)) {
+      // /proc is not always mounted under Linux (chroot for example).
+      ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path));
+      if (len >= 0)
+          return Path(StringRef(exe_path, len));
+  } else {
+      // Fall back to the classical detection.
+      if (getprogpath(exe_path, argv0) != NULL)
+          return Path(exe_path);
+  }
 #elif defined(HAVE_DLFCN_H)
   // Use dladdr to get executable path if available.
   Dl_info DLInfo;