Fix #78 with new c'tor for read_input.

taocpp · Dec 10, 2017 · 60b6987 · 60b6987
1 parent 78eb286
commit 60b6987
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Showing 4 changed files with 53 additions and 17 deletions.
diff --git a/doc/Inputs-and-Parsing.md b/doc/Inputs-and-Parsing.md
@@ -72,15 +72,20 @@ The classes `file_input<>`, `read_input<>` and, on supported platforms, `mmap_in
 * `mmap_input<>` uses `mmap(2)` and is available on POSIX compliant systems.
 * `file_input<>` is a type alias for `mmap_input<>` when available, and `read_input<>` otherwise.
 
-All file input classes take a single argument, the filename, which can be supplied as `std::string` or `const char*`.
+Most file input classes take a single argument, the filename, which can be supplied as `std::string` or `const char*`.
 They immediately make available the complete contents of the file; `read_input<>` reads the entire file upon construction.
 
+The constructors that take a `FILE*` argument take ownership of the file pointer, i.e. they `fclose()` it in the destructor.
+
 ```c++
 template< tracking_mode P = tracking_mode::IMMEDIATE, typename Eol = eol::lf_crlf >
 struct read_input
 {
    explicit read_input( const char* filename );
    explicit read_input( const std::string& filename );
+
+   read_input( FILE* file, const char* filename );
+   read_input( FILE* file, const std::string& filename );
 };
 
 template< tracking_mode P = tracking_mode::IMMEDIATE, typename Eol = eol::lf_crlf >

diff --git a/include/tao/pegtl/internal/file_reader.hpp b/include/tao/pegtl/internal/file_reader.hpp
@@ -18,6 +18,21 @@ namespace tao
    {
       namespace internal
       {
+         std::FILE* file_open( const char* source )
+         {
+            errno = 0;
+#if defined( _MSC_VER )
+            std::FILE* file;
+            if(::fopen_s( &file, source, "rb" ) == 0 )
+#else
+            if( auto* file = std::fopen( source, "rb" ) )
+#endif
+            {
+               return file;
+            }
+            TAOCPP_PEGTL_THROW_INPUT_ERROR( "unable to fopen() file " << source << " for reading" );
+         }
+
          struct file_close
          {
             void operator()( FILE* f ) const
@@ -31,7 +46,13 @@ namespace tao
          public:
             explicit file_reader( const char* filename )
                : m_source( filename ),
-                 m_file( open() )
+                 m_file( file_open( m_source ) )
+            {
+            }
+
+            file_reader( FILE* file, const char* filename )
+               : m_source( filename ),
+                 m_file( file )
             {
             }
 
@@ -70,21 +91,6 @@ namespace tao
          private:
             const char* const m_source;
             const std::unique_ptr< std::FILE, file_close > m_file;
-
-            std::FILE* open() const
-            {
-               errno = 0;
-#if defined( _MSC_VER )
-               std::FILE* file;
-               if(::fopen_s( &file, m_source, "rb" ) == 0 )
-#else
-               if( auto* file = std::fopen( m_source, "rb" ) )
-#endif
-               {
-                  return file;
-               }
-               TAOCPP_PEGTL_THROW_INPUT_ERROR( "unable to fopen() file " << m_source << " for reading" );
-            }
          };
 
       }  // namespace internal

diff --git a/include/tao/pegtl/read_input.hpp b/include/tao/pegtl/read_input.hpp
@@ -43,6 +43,13 @@ namespace tao
               string_input< P, Eol, const char* >( internal::file_reader( filename.c_str() ).read(), filename.c_str() )
          {
          }
+
+         template< typename T >
+         read_input( FILE* in_file, T&& in_filename )
+            : internal::filename_holder( std::forward< T >( in_filename ) ),
+              string_input< P, Eol, const char* >( internal::file_reader( in_file, filename.c_str() ).read(), filename.c_str() )
+         {
+         }
       };
 
    }  // namespace TAOCPP_PEGTL_NAMESPACE

diff --git a/src/test/pegtl/file_read.cpp b/src/test/pegtl/file_read.cpp
@@ -9,9 +9,27 @@ namespace tao
 {
    namespace TAOCPP_PEGTL_NAMESPACE
    {
+      template< tracking_mode P = tracking_mode::IMMEDIATE, typename Eol = eol::lf_crlf >
+      struct open_input
+         : public read_input< P, Eol >
+      {
+         explicit
+         open_input( const char* filename )
+            : read_input< P, Eol >( internal::file_open( filename ), filename )
+         {
+         }
+
+         explicit
+         open_input( const std::string& filename )
+            : open_input( filename.c_str() )
+         {
+         }
+      };
+
       void unit_test()
       {
          verify_file< read_input<> >();
+         verify_file< open_input<> >();
       }
 
    }  // namespace TAOCPP_PEGTL_NAMESPACE