From 1a803295d08f1d562b4cebcb830edd874ec16d79 Mon Sep 17 00:00:00 2001
From: Sylvestre Ledru <sylvestre@debian.org>
Date: Mon, 9 Dec 2013 16:27:00 +0000
Subject: [PATCH] Improve the detection of the path

Summary:
When clang is used under GNU/Linux in a chroot without /proc mount, it falls
back on the BSD method. However, since the buf variable is used twice
and fails with snprintf to produce the correct path.

When called as relatived (ie ./clang), it was failing with:
 "" -cc1 [...] -x c++ x.cc
error: unable to execute command: Executable "" doesn't exist!


I also took the opportunity to simply the code (the first arg of test_dir
was useless).

Reviewers: rafael

Reviewed By: rafael

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2361

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196791 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Support/Unix/Path.inc | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
index 6e08c63c1fa..734ea5d110a 100644
--- a/lib/Support/Unix/Path.inc
+++ b/lib/Support/Unix/Path.inc
@@ -184,15 +184,15 @@ namespace fs {
     defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \
     defined(__linux__) || defined(__CYGWIN__) || defined(__DragonFly__)
 static int
-test_dir(char buf[PATH_MAX], char ret[PATH_MAX],
-    const char *dir, const char *bin)
-{
+test_dir(char ret[PATH_MAX], const char *dir, const char *bin)
+{  
   struct stat sb;
+  char fullpath[PATH_MAX];
 
-  snprintf(buf, PATH_MAX, "%s/%s", dir, bin);
-  if (realpath(buf, ret) == NULL)
+  snprintf(fullpath, PATH_MAX, "%s/%s", dir, bin);
+  if (realpath(fullpath, ret) == NULL)
     return (1);
-  if (stat(buf, &sb) != 0)
+  if (stat(fullpath, &sb) != 0)
     return (1);
 
   return (0);
@@ -201,20 +201,21 @@ test_dir(char buf[PATH_MAX], char ret[PATH_MAX],
 static char *
 getprogpath(char ret[PATH_MAX], const char *bin)
 {
-  char *pv, *s, *t, buf[PATH_MAX];
+  char *pv, *s, *t;
 
   /* First approach: absolute path. */
   if (bin[0] == '/') {
-    if (test_dir(buf, ret, "/", bin) == 0)
+    if (test_dir(ret, "/", bin) == 0)
       return (ret);
     return (NULL);
   }
 
   /* Second approach: relative path. */
   if (strchr(bin, '/') != NULL) {
-    if (getcwd(buf, PATH_MAX) == NULL)
+    char cwd[PATH_MAX];
+    if (getcwd(cwd, PATH_MAX) == NULL)
       return (NULL);
-    if (test_dir(buf, ret, buf, bin) == 0)
+    if (test_dir(ret, cwd, bin) == 0)
       return (ret);
     return (NULL);
   }
@@ -226,7 +227,7 @@ getprogpath(char ret[PATH_MAX], const char *bin)
   if (pv == NULL)
     return (NULL);
   while ((t = strsep(&s, ":")) != NULL) {
-    if (test_dir(buf, ret, t, bin) == 0) {
+    if (test_dir(ret, t, bin) == 0) {
       free(pv);
       return (ret);
     }