src/mmloader.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2006-2008 Floréal Morandat <morandat@lirmm.fr>
   4 # Copyright 2008 Jean Privat <jean@pryen.org>
   5 # Copyright 2009 Jean-Sebastien Gelinas <calestar@gmail.com>
   6 #
   7 # Licensed under the Apache License, Version 2.0 (the "License");
   8 # you may not use this file except in compliance with the License.
   9 # You may obtain a copy of the License at
  10 #
  11 #     http://www.apache.org/licenses/LICENSE-2.0
  12 #
  13 # Unless required by applicable law or agreed to in writing, software
  14 # distributed under the License is distributed on an "AS IS" BASIS,
  15 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16 # See the License for the specific language governing permissions and
  17 # limitations under the License.
  18
  19 # This package is used to load a metamodel
  20 package mmloader
  21
  22 import metamodel
  23 import opts
  24 import location
  25
  26 private class Message
  27         readable attr _location: nullable Location
  28         readable attr _text: String
  29 end
  30
  31 # Global context for tools
  32 class ToolContext
  33 special MMContext
  34         # Number of errors
  35         readable var _error_count: Int = 0
  36
  37         # Number of warnings
  38         readable var _warning_count: Int = 0
  39
  40         # Messages
  41         var _messages: Array[Message] = new Array[Message]
  42
  43         fun check_errors
  44         do
  45                 if _messages.length > 0 then
  46                         for m in _messages do
  47                                 stderr.write("{m.text}\n")
  48                         end
  49
  50                         _messages.clear
  51                 end
  52
  53                 if error_count > 0 then exit(1)
  54         end
  55
  56         # Display an error
  57         fun error(l: nullable Location, s: String)
  58         do
  59                 _messages.add(new Message(l,s))
  60                 _error_count = _error_count + 1
  61         end
  62
  63         # Display a warning
  64         fun warning(l: nullable Location, s: String)
  65         do
  66                 if _opt_warn.value == 0 then return
  67                 _messages.add(new Message(l,s))
  68                 if _opt_warn.value == 1 then
  69                         _warning_count = _warning_count + 1
  70                 else
  71                         _error_count = _error_count + 1
  72                 end
  73         end
  74
  75         # Display an info
  76         meth info(s: String, level: Int)
  77         do
  78                 if level <= verbose_level then
  79                         print "{s}"
  80                 end
  81         end
  82
  83         # Paths where to locate modules files
  84         readable var _paths: Array[String] = new Array[String]
  85
  86         # List of module loaders
  87         var _loaders: Array[ModuleLoader] = new Array[ModuleLoader]
  88
  89         # Global OptionContext
  90         readable var _option_context: OptionContext = new OptionContext
  91
  92         # Option --warn
  93         readable var _opt_warn: OptionCount = new OptionCount("Show warnings", "-W", "--warn")
  94
  95         # Option --path
  96         readable var _opt_path: OptionArray = new OptionArray("Set include path for loaders (may be used more than once)", "-I", "--path")
  97
  98         # Option --lop
  99         readable var _opt_log: OptionBool = new OptionBool("Generate various log files", "--log")
 100
 101         # Option --only-metamodel
 102         readable var _opt_only_metamodel: OptionBool = new OptionBool("Stop after meta-model processing", "--only-metamodel")
 103
 104         # Option --only-parse
 105         readable var _opt_only_parse: OptionBool = new OptionBool("Only proceed to parse step of loaders", "--only-parse")
 106
 107         # Option --help
 108         readable var _opt_help: OptionBool = new OptionBool("Show Help (This screen)", "-h", "-?", "--help")
 109
 110         # Option --version
 111         readable var _opt_version: OptionBool = new OptionBool("Show version and exit", "--version")
 112
 113         # Option --verbose
 114         readable var _opt_verbose: OptionCount = new OptionCount("Verbose", "-v", "--verbose")
 115
 116         # Verbose level
 117         readable var _verbose_level: Int = 0
 118
 119         init
 120         do
 121                 super
 122                 option_context.add_option(opt_warn, opt_path, opt_log, opt_only_parse, opt_only_metamodel, opt_help, opt_version, opt_verbose)
 123         end
 124
 125         # Parse and process the options given on the command line
 126         fun process_options
 127         do
 128                 # init options
 129                 option_context.parse(args)
 130
 131                 # Set verbose level
 132                 _verbose_level = opt_verbose.value
 133
 134                 # Setup the paths value
 135                 paths.append(opt_path.value)
 136
 137                 var path_env = once ("NIT_PATH".to_symbol).environ
 138                 if not path_env.is_empty then
 139                         paths.append(path_env.split_with(':'))
 140                 end
 141
 142                 path_env = once ("NIT_DIR".to_symbol).environ
 143                 if not path_env.is_empty then
 144                         var libname = "{path_env}/lib"
 145                         if libname.file_exists then paths.add(libname)
 146                 end
 147
 148                 var libname = "{sys.program_name.dirname}/../lib"
 149                 if libname.file_exists then paths.add(libname)
 150         end
 151
 152         # Load and process a module in a directory (or a parent directory).
 153         # If the module is already loaded, just return it without further processing.
 154         # If no module is found, just return null without complaining.
 155         private fun try_to_load(module_name: Symbol, dir: MMDirectory): nullable MMModule
 156         do
 157                 # Look in the module directory
 158                 for m in dir.modules do
 159                         if m.name == module_name then return m
 160                 end
 161
 162                 # print "try to load {module_name} in {dir.name} {_loaders.length}"
 163
 164                 for l in _loaders do
 165                         var dir2 = l.try_to_load_dir(module_name, dir)
 166                         if dir2 != null then
 167                                 var m = try_to_load(module_name, dir2)
 168                                 if m != null then
 169                                         dir2.owner = m
 170                                         dir.add_module(m)
 171                                         return m
 172                                 end
 173                         end
 174
 175                         if l.can_handle(module_name, dir) then
 176                                 var full_name = dir.full_name_for(module_name)
 177                                 if _processing_modules.has(full_name) then
 178                                         # FIXME: Generate better error
 179                                         error(null, "Error: Dependency loop for module {full_name}")
 180                                         check_errors
 181                                 end
 182                                 _processing_modules.add(full_name)
 183                                 var m = l.load_and_process_module(self, module_name, dir)
 184                                 _processing_modules.remove(full_name)
 185                                 #if m != null then print "loaded {m.name} in {m.directory.name} -> {m.full_name} ({m.full_name.object_id.to_hex})"
 186                                 dir.add_module(m)
 187                                 return m
 188                         end
 189                 end
 190                 return null
 191         end
 192
 193         # List of module currently processed.
 194         # Used to prevent dependence loops.
 195         var _processing_modules: HashSet[Symbol] = new HashSet[Symbol]
 196
 197         # Locate, load and analysis a module (and its supermodules) from its file name.
 198         # If the module is already loaded, just return it without further processing.
 199         # Beware, the files are automatically considered root of their directory.
 200         fun get_module_from_filename(filename: String): MMModule
 201         do
 202                 var path = filename.dirname
 203                 var module_name = filename.basename(".nit").to_symbol
 204
 205                 var dir = directory_for(path)
 206
 207                 if module_name.to_s == filename then
 208                         # It's just a modulename
 209                         # look for it in the path directory "."
 210                         var m = try_to_load(module_name, dir)
 211                         if m != null then return m
 212
 213                         # Else look for it in the path
 214                         return get_module(module_name, null)
 215                 end
 216
 217                 if not filename.file_exists then
 218                         error(null, "Error: File {filename} not found.")
 219                         check_errors
 220                         abort
 221                 end
 222
 223                 # Try to load the module where mentionned
 224                 var m = try_to_load(module_name, dir)
 225                 if m != null then return m
 226
 227                 error(null, "Error: {filename} is not a NIT source module.")
 228                 check_errors
 229                 abort
 230         end
 231
 232         # Locate, load and analysis a module (and its supermodules).
 233         # If the module is already loaded, just return it without further processing.
 234         fun get_module(module_name: Symbol, from: nullable MMModule): MMModule
 235         do
 236                 var m: MMModule
 237                 if from != null then
 238                         var dir: nullable MMDirectory = from.directory
 239                         while dir != null do
 240                                 var m = try_to_load(module_name, dir)
 241                                 if m != null then return m
 242                                 dir = dir.parent
 243                         end
 244                 end
 245
 246                 for p in paths do
 247                         var m = try_to_load(module_name, directory_for(p))
 248                         if m != null then return m
 249                 end
 250                 # FIXME: Generate better error
 251                 error(null, "Error: No ressource found for module {module_name}.")
 252                 check_errors
 253                 abort
 254         end
 255
 256         # Return the module directory associated with a given path
 257         private fun directory_for(path: String): MMDirectory
 258         do
 259                 if _path_dirs.has_key(path) then return _path_dirs[path]
 260                 var dir = new MMDirectory(path.to_symbol, path, null)
 261                 _path_dirs[path] = dir
 262                 return dir
 263         end
 264
 265         # Association bwtween plain path and module directories
 266         var _path_dirs: Map[String, MMDirectory] = new HashMap[String, MMDirectory]
 267
 268         # Register a new module loader
 269         fun register_loader(ml: ModuleLoader) do _loaders.add(ml)
 270 end
 271
 272 # A load handler know how to load a specific module type
 273 class ModuleLoader
 274         # Type of module loaded by the loader
 275         type MODULE: MMModule
 276
 277         # Extension that the loadhandler accepts
 278         fun file_type: String is abstract
 279
 280         # Try to load a new module directory
 281         fun try_to_load_dir(dirname: Symbol, parent_dir: MMDirectory): nullable MMDirectory
 282         do
 283                 var fname = "{parent_dir.path}/{dirname}/"
 284                 if not fname.file_exists then return null
 285
 286                 var dir = new MMDirectory(parent_dir.full_name_for(dirname), fname, parent_dir)
 287                 return dir
 288         end
 289
 290         # Can the loadhandler load a given module?
 291         # Return the file found
 292         fun can_handle(module_name: Symbol, dir: MMDirectory): Bool
 293         do
 294                 var fname = "{dir.path}/{module_name}.{file_type}"
 295                 if fname.file_exists then return true
 296                 return false
 297         end
 298
 299         # Load the module and process it
 300         # filename is the result of can_handle
 301         fun load_and_process_module(context: ToolContext, module_name: Symbol, dir: MMDirectory): MODULE
 302         do
 303                 var filename = "{dir.path}/{module_name}.{file_type}"
 304                 var m = load_module(context, module_name, dir, filename)
 305                 if not context.opt_only_parse.value then process_metamodel(context, m)
 306                 return m
 307         end
 308
 309         # Load an parse the module
 310         private fun load_module(context: ToolContext, module_name: Symbol, dir: MMDirectory, filename: String): MODULE
 311         do
 312                 var file: IFStream
 313                 if filename == "-" then
 314                         file = stdin
 315                 else
 316                         file = new IFStream.open(filename.to_s)
 317                 end
 318
 319                 if file.eof then
 320                         context.error(null, "Error: Problem in opening file {filename}")
 321                         context.check_errors
 322                 end
 323                 var m = parse_file(context, file, filename, module_name, dir)
 324                 if file != stdin then file.close
 325                 return m
 326         end
 327
 328         # Parse the file to load a module
 329         protected fun parse_file(context: ToolContext, file: IFStream, filename: String, module_name: Symbol, dir: MMDirectory): MODULE is abstract
 330
 331         # Process a parsed module
 332         protected fun process_metamodel(context: ToolContext, module: MODULE) is abstract
 333 end
 334
 335 redef class MMModule
 336         # Recurcivelty process an import modules
 337         fun import_supers_modules(names: Collection[Symbol])
 338         do
 339                 var c = context
 340                 assert c isa ToolContext
 341                 var supers = new Array[MMModule]
 342                 for n in names do
 343                         var m = c.get_module(n, self)
 344                         supers.add(m)
 345                 end
 346                 c.add_module(self,supers)
 347         end
 348 end