contrib/objcwrapper/src/preprocessing.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # Preprocessing of input files
  16 module preprocessing
  17
  18 import header_static
  19 import header_keeper
  20
  21 import opts
  22
  23 redef class Sys
  24         # Options for the C preprocessor
  25         var opt_gcc_options = new OptionString("C Preprocessor options to add to `gcc -E file`", "-p")
  26 end
  27
  28 redef class Text
  29         # Read file at `self` and preprocess its content through `gcc -E`, `header_keeper` and `header_static`
  30         fun preprocess_content: String
  31         do
  32                 var path = to_s
  33
  34                 # GCC C preprocessor, to apply macros and includes
  35                 var gcc_opts = opt_gcc_options.value or else ""
  36                 var cmd = "gcc -E {path} {gcc_opts}"
  37                 var gcc_proc = new ProcessReader("sh", "-c", cmd)
  38
  39                 # header_keeper, to keep only the target file (path)
  40                 var o = new StringWriter
  41                 header_keeper(gcc_proc, o, path)
  42
  43                 gcc_proc.wait
  44                 if gcc_proc.status != 0 then
  45                         print_error "Fatal Error: call to gcc failed, the command was: {cmd}"
  46                         exit 1
  47                 end
  48
  49                 # header_static, strip lines unsupported by our parser
  50                 var i = new StringReader(o.to_s)
  51                 o = new StringWriter
  52                 header_static(i, o)
  53
  54                 return o.to_s
  55         end
  56 end