Adding GetOutputDir method to test_support library.

The unittest is not ideal for this, but I would have to use similar code as the implementation of the GetOutputDir in order to verify that it actually runs, so it wouldn't make much sense with a test like that.

It compiles and runs on Linux, Win and Mac. The folder gets created and is writeable from other tests.

I have tried using the GetOutputDir from another project that writes output files and it works as intended on all platforms.

Review URL: http://webrtc-codereview.appspot.com/270001

git-svn-id: http://webrtc.googlecode.com/svn/trunk@906 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/test/testsupport/fileutils.cc b/test/testsupport/fileutils.cc
index 098dad7..9b54989 100644
--- a/test/testsupport/fileutils.cc
+++ b/test/testsupport/fileutils.cc
@@ -13,11 +13,14 @@
 #ifdef WIN32
 #include <direct.h>
 #define GET_CURRENT_DIR _getcwd
-#define PATH_DELIMITER "\\"
 #else
 #include <unistd.h>
 #define GET_CURRENT_DIR getcwd
-#define PATH_DELIMITER "/"
+#endif
+
+#include <sys/stat.h>  // To check for directory existence.
+#ifndef S_ISDIR  // Not defined in stat.h on Windows.
+#define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
 #endif
 
 #include <cstdio>
@@ -25,8 +28,14 @@
 namespace webrtc {
 namespace test {
 
+#ifdef WIN32
+static const char* kPathDelimiter = "\\";
+#else
+static const char* kPathDelimiter = "/";
+#endif
 // The file we're looking for to identify the project root dir.
 static const char* kProjectRootFileName = "DEPS";
+static const char* kOutputDirName = "out";
 const char* kCannotFindProjectRootDir = "ERROR_CANNOT_FIND_PROJECT_ROOT_DIR";
 
 std::string GetProjectRootPath() {
@@ -39,18 +48,18 @@
   // Check for our file that verifies the root dir.
   std::string current_path(path_buffer);
   FILE* file = NULL;
-  int path_delimiter_index = current_path.find_last_of(PATH_DELIMITER);
+  int path_delimiter_index = current_path.find_last_of(kPathDelimiter);
   while (path_delimiter_index > -1) {
-    std::string root_filename = current_path + PATH_DELIMITER +
+    std::string root_filename = current_path + kPathDelimiter +
         kProjectRootFileName;
     file = fopen(root_filename.c_str(), "r");
     if (file != NULL) {
-      return current_path + PATH_DELIMITER;
+      return current_path + kPathDelimiter;
     }
 
     // Move up one directory in the directory tree.
     current_path = current_path.substr(0, path_delimiter_index);
-    path_delimiter_index = current_path.find_last_of(PATH_DELIMITER);
+    path_delimiter_index = current_path.find_last_of(kPathDelimiter);
   }
 
   // Reached the root directory.
@@ -58,5 +67,28 @@
   return kCannotFindProjectRootDir;
 }
 
-}  // namespace webrtc
+std::string GetOutputDir() {
+  std::string path = GetProjectRootPath();
+  if (path == kCannotFindProjectRootDir) {
+    return kCannotFindProjectRootDir;
+  }
+  path += kOutputDirName;
+  struct stat path_info = {0};
+  // Check if the path exists already:
+  if (stat(path.c_str(), &path_info) == 0) {
+    if (!S_ISDIR(path_info.st_mode)) {
+      fprintf(stderr, "Path %s exists but is not a directory! Remove this file "
+              "and re-run to create the output folder.\n", path.c_str());
+      return kCannotFindProjectRootDir;
+    }
+  } else {
+#ifdef WIN32
+      _mkdir(path.c_str());
+#else
+      mkdir(path.c_str(),  S_IRWXU | S_IRWXG | S_IRWXO);
+#endif
+  }
+  return path + kPathDelimiter;
+}
 }  // namespace test
+}  // namespace webrtc