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