Move from readdir_r to readdir (#1955)

FAQ.md

@@ -490,8 +490,6 @@ group](https://groups.google.com/group/libphonenumber-discuss):
 *   PR [#1090](https://github.com/googlei18n/libphonenumber/pull/1090) /
     [#824](https://github.com/googlei18n/libphonenumber/issues/824) to "Replace
     POSIX directory operations by Boost Filesystem"
-*   [#1307](https://github.com/googlei18n/libphonenumber/issues/1307) to use
-    readdir instead of readdir_r
 *   [#1555](https://github.com/googlei18n/libphonenumber/issues/1555) to allow
     Windows to build cpp library with pthreads for multi-threading
 

pending_code_changes.txt

@@ -1 +1,2 @@
-
+Build changes:
+ - C++ geocoding build tools now use readdir, since readdir_r is deprecated.

tools/cpp/src/cpp-build/generate_geocoding_data.cc

@@ -17,6 +17,7 @@
 #include "cpp-build/generate_geocoding_data.h"
 
 #include <dirent.h>
+#include <errno.h>
 #include <locale>
 #include <sys/stat.h>
 #include <algorithm>
@@ -102,20 +103,24 @@ bool ListDirectory(const string& path, vector<DirEntry>* entries) {
     return false;
   }
   AutoCloser<DIR> dir_closer(&dir, closedir);
-  struct dirent entry, *dir_result;
+  struct dirent *entry;
   struct stat entry_stat;
   while (true) {
-    const int res = readdir_r(dir, &entry, &dir_result);
-    if (res) {
-      return false;
-    }
-    if (dir_result == NULL) {
-      return true;
+    // Set errno to 0 to be able to check if an error occurs during the
+    // readdir() call. NULL is the return value when the end of the directory
+    // stream is reached or when an error occurs, and the errno check is the
+    // only thing that helps us distinguish between the two cases. See
+    // documentation at
+    // http://pubs.opengroup.org/onlinepubs/9699919799/functions/readdir.html
+    errno = 0;
+    entry = readdir(dir);
+    if (entry == NULL) {
+      return errno == 0;
     }
-    if (strcmp(entry.d_name, ".") == 0 || strcmp(entry.d_name, "..") == 0) {
+    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
        continue;
     }
-    const string entry_path = path + "/" + entry.d_name;
+    const string entry_path = path + "/" + entry->d_name;
     if (stat(entry_path.c_str(), &entry_stat)) {
       return false;
     }
@@ -125,7 +130,7 @@ bool ListDirectory(const string& path, vector<DirEntry>* entries) {
     } else if (!S_ISREG(entry_stat.st_mode)) {
       continue;
     }
-    entries->push_back(DirEntry(entry.d_name, kind));
+    entries->push_back(DirEntry(entry->d_name, kind));
   }
 }