Fix incorrectly finding 'executable' directories instead of files.

This broke for example the 'not' utility, if a directory called
'FileCheck' is executable and in the path before the actual 'FileCheck'.

This patch steals the implementation of the "old" PathV1 canExecute
implementation:
- checks for R_OK (file readable): this is necessary for executing
  scripts; we should not regress here unless we have good reasons
- checks for S_ISREG; if we want to get rid of this, we'd need to
  change all callers who already made the assumption when depending
  on Path V1.

llvm-svn: 184074

1 files changed, 8 insertions, 1 deletions

diff --git a/llvm/lib/Support/Unix/PathV2.inc b/llvm/lib/Support/Unix/PathV2.inc
index df8841220b5..68c17d534cd 100644
--- a/llvm/lib/Support/Unix/PathV2.inc
+++ b/llvm/lib/Support/Unix/PathV2.inc
@@ -296,7 +296,14 @@ bool can_execute(const Twine &Path) {
   SmallString<128> PathStorage;
   StringRef P = Path.toNullTerminatedStringRef(PathStorage);
 
-  return ::access(P.begin(), X_OK) != -1;
+  if (0 != access(P.begin(), R_OK | X_OK))
+    return false;
+  struct stat buf;
+  if (0 != stat(P.begin(), &buf))
+    return false;
+  if (!S_ISREG(buf.st_mode))
+    return false;
+  return true;
 }
 
 bool equivalent(file_status A, file_status B) {