Remove use of std::filesystem / boost::filesystem

Boost doesn't buy us anything here since we need to maintain
Win32 and POSIX implementations for non-Boost builds, and Boost
only supports those two APIs anyway.

MSVC's implementation of std::filesystem does not help for similar
reasons, as we have to maintain a Win32 version for MinGW.

3 files changed, 8 insertions, 70 deletions

diff --git a/src/build-data/os/windows.txt b/src/build-data/os/windows.txt
index 209df6e03..8eab164df 100644
--- a/src/build-data/os/windows.txt
+++ b/src/build-data/os/windows.txt
@@ -29,7 +29,6 @@ rtlgenrandom
 rtlsecurezeromemory
 
 virtual_lock
-stl_filesystem_msvc
 
 threads
 filesystem
diff --git a/src/lib/utils/boost/info.txt b/src/lib/utils/boost/info.txt
index d54421147..6330cbafd 100644
--- a/src/lib/utils/boost/info.txt
+++ b/src/lib/utils/boost/info.txt
@@ -1,10 +1,9 @@
 <defines>
-BOOST_FILESYSTEM -> 20131228
 BOOST_ASIO -> 20131228
 </defines>
 
 load_on vendor
 
 <libs>
-all -> boost_system,boost_filesystem
+all -> boost_system
 </libs>
diff --git a/src/lib/utils/filesystem.cpp b/src/lib/utils/filesystem.cpp
index 053c91e70..3072a304f 100644
--- a/src/lib/utils/filesystem.cpp
+++ b/src/lib/utils/filesystem.cpp
@@ -1,5 +1,5 @@
 /*
-* (C) 2015,2017 Jack Lloyd
+* (C) 2015,2017,2019 Jack Lloyd
 * (C) 2015 Simon Warta (Kullo GmbH)
 *
 * Botan is released under the Simplified BSD License (see license.txt)
@@ -8,77 +8,25 @@
 #include <botan/exceptn.h>
 #include <botan/internal/filesystem.h>
 #include <algorithm>
+#include <deque>
+#include <memory>
 
-#if defined(BOTAN_TARGET_OS_HAS_STL_FILESYSTEM_MSVC) && defined(BOTAN_BUILD_COMPILER_IS_MSVC)
-  #include <filesystem>
-#elif defined(BOTAN_HAS_BOOST_FILESYSTEM)
-  #include <boost/filesystem.hpp>
-#elif defined(BOTAN_TARGET_OS_HAS_POSIX1)
+#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
   #include <sys/types.h>
   #include <sys/stat.h>
   #include <dirent.h>
-  #include <deque>
-  #include <memory>
   #include <functional>
 #elif defined(BOTAN_TARGET_OS_HAS_WIN32)
   #define NOMINMAX 1
   #define _WINSOCKAPI_ // stop windows.h including winsock.h
   #include <windows.h>
-  #include <deque>
-  #include <memory>
 #endif
 
 namespace Botan {
 
 namespace {
 
-#if defined(BOTAN_TARGET_OS_HAS_STL_FILESYSTEM_MSVC) && defined(BOTAN_BUILD_COMPILER_IS_MSVC)
-std::vector<std::string> impl_stl_filesystem(const std::string& dir)
-   {
-#if (_MSVC_LANG >= 201703L)
-   using namespace std::filesystem;
-#else
-   using namespace std::tr2::sys;
-#endif
-
-   std::vector<std::string> out;
-
-   path p(dir);
-
-   if(is_directory(p))
-      {
-      for(recursive_directory_iterator itr(p), end; itr != end; ++itr)
-         {
-         if(is_regular_file(itr->path()))
-            {
-            out.push_back(itr->path().string());
-            }
-         }
-      }
-
-   return out;
-   }
-
-#elif defined(BOTAN_HAS_BOOST_FILESYSTEM)
-
-std::vector<std::string> impl_boost_filesystem(const std::string& dir_path)
-{
-   namespace fs = boost::filesystem;
-
-   std::vector<std::string> out;
-
-   for(fs::recursive_directory_iterator dir(dir_path), end; dir != end; ++dir)
-      {
-      if(fs::is_regular_file(dir->path()))
-         {
-         out.push_back(dir->path().string());
-         }
-      }
-
-   return out;
-}
-
-#elif defined(BOTAN_TARGET_OS_HAS_POSIX1)
+#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
 
 std::vector<std::string> impl_readdir(const std::string& dir_path)
    {
@@ -166,11 +114,7 @@ std::vector<std::string> impl_win32(const std::string& dir_path)
 
 bool has_filesystem_impl()
    {
-#if defined(BOTAN_TARGET_OS_HAS_STL_FILESYSTEM_MSVC) && defined(BOTAN_BUILD_COMPILER_IS_MSVC)
-   return true;
-#elif defined(BOTAN_HAS_BOOST_FILESYSTEM)
-   return true;
-#elif defined(BOTAN_TARGET_OS_HAS_POSIX1)
+#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
    return true;
 #elif defined(BOTAN_TARGET_OS_HAS_WIN32)
    return true;
@@ -183,11 +127,7 @@ std::vector<std::string> get_files_recursive(const std::string& dir)
    {
    std::vector<std::string> files;
 
-#if defined(BOTAN_TARGET_OS_HAS_STL_FILESYSTEM_MSVC) && defined(BOTAN_BUILD_COMPILER_IS_MSVC)
-   files = impl_stl_filesystem(dir);
-#elif defined(BOTAN_HAS_BOOST_FILESYSTEM)
-   files = impl_boost_filesystem(dir);
-#elif defined(BOTAN_TARGET_OS_HAS_POSIX1)
+#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
    files = impl_readdir(dir);
 #elif defined(BOTAN_TARGET_OS_HAS_WIN32)
    files = impl_win32(dir);