[Boost-commit] svn:boost r72855 - in trunk: boost/filesystem/v3 libs/filesystem/v3/src

Subject: [Boost-commit] svn:boost r72855 - in trunk: boost/filesystem/v3 libs/filesystem/v3/src
From: bdawes_at_[hidden]
Date: 2011-07-02 10:43:19

Author: bemandawes
Date: 2011-07-02 10:43:18 EDT (Sat, 02 Jul 2011)
New Revision: 72855
URL: http://svn.boost.org/trac/boost/changeset/72855

Log:
Fix problem of locale("") exception being thrown before main() starts on misconfigured (e.g. LANG="bad name") POSIX systems. Resolves the most serious aspect of tickets 4688, 5100, 5289.
Text files modified: 
   trunk/boost/filesystem/v3/path.hpp    |    13 ++++++++++++-                           
   trunk/libs/filesystem/v3/src/path.cpp |    37 +++++++++++++++++++++----------------   
   2 files changed, 33 insertions(+), 17 deletions(-)

Modified: trunk/boost/filesystem/v3/path.hpp
==============================================================================
--- trunk/boost/filesystem/v3/path.hpp	(original)
+++ trunk/boost/filesystem/v3/path.hpp	2011-07-02 10:43:18 EDT (Sat, 02 Jul 2011)
@@ -125,7 +125,7 @@
     path(){}                                          
 
     path(const path& p) : m_pathname(p.m_pathname) {}
- 
+
     template <class Source>
     path(Source const& source,
       typename boost::enable_if<path_traits::is_pathable<
@@ -134,6 +134,17 @@
       path_traits::dispatch(source, m_pathname, codecvt());
     }
 
+    //  Overloads for the operating system API's native character type. Rationale:
+    //    - Avoids use of codecvt() for native value_type strings. This limits the
+    //      impact of locale("") initialization failures on POSIX systems to programs
+    //      that actually depend on locale(""). It further ensures that exceptions thrown
+    //      as a result of such failues occur after main() has started, so can be caught.
+    //      This is a partial resolution of tickets 4688, 5100, and 5289.
+    //    - A slight optimization for a common use case, particularly on POSIX since
+    //      value_type is char and that is the most common useage.
+    path(const value_type* s) : m_pathname(s) {}
+    path(const std::basic_string<value_type>& s) : m_pathname(s) {}
+
     template <class Source>
     path(Source const& source, const codecvt_type& cvt)
     //  see note above explaining why codecvt() default arguments are not used

Modified: trunk/libs/filesystem/v3/src/path.cpp
==============================================================================
--- trunk/libs/filesystem/v3/src/path.cpp	(original)
+++ trunk/libs/filesystem/v3/src/path.cpp	2011-07-02 10:43:18 EDT (Sat, 02 Jul 2011)
@@ -727,11 +727,6 @@
   //                              locale helpers                                        //
   //------------------------------------------------------------------------------------//
 
-  // std::locale construction can throw (if LC_MESSAGES is wrong, for example),
-  // so a static at function scope is used to ensure that exceptions can be
-  // caught. (A previous version was at namespace scope, so initialization
-  // occurred before main(), preventing exceptions from being caught.)
-
   std::locale default_locale()
   {
 #   ifdef BOOST_WINDOWS_API
@@ -741,32 +736,43 @@
 
 #   elif defined(macintosh) || defined(__APPLE__) || defined(__APPLE_CC__)
     // "All BSD system functions expect their string parameters to be in UTF-8 encoding
-    // and nothing else." http://developer.apple.com/mac/library/documentation/MacOSX/Conceptual/BPInternational/Articles/FileEncodings.html
+    // and nothing else." See
+    // http://developer.apple.com/mac/library/documentation/MacOSX/Conceptual/BPInternational/Articles/FileEncodings.html
     //
     // "The kernel will reject any filename that is not a valid UTF-8 string, and it will
     // even be normalized (to Unicode NFD) before stored on disk, at least when using HFS.
     // The right way to deal with it would be to always convert the filename to UTF-8
-    // before trying to open/create a file." http://lists.apple.com/archives/unix-porting/2007/Sep/msg00023.html
+    // before trying to open/create a file." See
+    // http://lists.apple.com/archives/unix-porting/2007/Sep/msg00023.html
     //
     // "How a file name looks at the API level depends on the API. Current Carbon APIs
     // handle file names as an array of UTF-16 characters; POSIX ones handle them as an
     // array of UTF-8, which is why UTF-8 works well in Terminal. How it's stored on disk
     // depends on the disk format; HFS+ uses UTF-16, but that's not important in most
-    // cases." http://lists.apple.com/archives/applescript-users/2002/Sep/msg00319.html
+    // cases." See
+    // http://lists.apple.com/archives/applescript-users/2002/Sep/msg00319.html
     //
     // Many thanks to Peter Dimov for digging out the above references!
+
     std::locale global_loc = std::locale();
     std::locale loc(global_loc, new boost::filesystem::detail::utf8_codecvt_facet);
     return loc;
 
-#   else
-    // ISO C calls this "the locale-specific native environment":
+#   else  // Other POSIX
+
+    // ISO C calls std::locale("") "the locale-specific native environment", and this
+    // locale is the default for many POSIX-based operating systems such as Linux.
+
+    // std::locale("") construction can throw (if environmental variables LC_MESSAGES or
+    // or LANG are wrong, for example), so dynamic initialization is used to ensure
+    // that exceptions can be caught.
+
     return std::locale("");
 
 #   endif
   }
 
-  std::locale & path_locale()
+  std::locale& path_locale()
   {
     static std::locale loc(default_locale());
     return loc;
@@ -783,8 +789,7 @@
 namespace filesystem3
 {
 
-  const path::codecvt_type *&
-    path::wchar_t_codecvt_facet()
+  const path::codecvt_type *& path::wchar_t_codecvt_facet()
   {
    static const std::codecvt<wchar_t, char, std::mbstate_t> *
      facet(
@@ -797,12 +802,12 @@
   {
     std::locale temp(path_locale());
     path_locale() = loc;
-    wchar_t_codecvt_facet() = &std::use_facet
-        <std::codecvt<wchar_t, char, std::mbstate_t> >(path_locale());
+    wchar_t_codecvt_facet() =
+      &std::use_facet<std::codecvt<wchar_t, char, std::mbstate_t> >(path_locale());
     return temp;
   }
 
 }  // namespace filesystem3
 }  // namespace boost
 
-#endif  // no wide character support
+#endif  // has wide character support