contrib/nitcc/nitcc.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 # nitcc, a parser and lexer generator for Nit
  16 module nitcc
  17
  18 import nitcc_semantic
  19
  20 # Load the grammar file
  21
  22 if args.is_empty then
  23         print "usage: nitcc <file> | -"
  24         exit 1
  25 end
  26 var fi = args.first
  27
  28 var text
  29 if fi != "-" then
  30         var f = new IFStream.open(fi)
  31         text = f.read_all
  32         f.close
  33 else
  34         text = stdin.read_all
  35 end
  36
  37 # Parse the grammar file
  38
  39 var l = new MyLexer(text)
  40 var ts = l.lex
  41
  42 var p = new MyParser
  43 p.tokens.add_all ts
  44
  45 var node = p.parse
  46
  47 if not node isa NProd then
  48         print node
  49         exit 1
  50         abort
  51 end
  52
  53 var name = node.children.first.as(Ngrammar).children[1].as(Nid).text
  54
  55 print "Grammar {name} (see {name}.gram.dot))"
  56 node.to_dot("{name}.gram.dot")
  57
  58 # Semantic analysis
  59
  60 var v2 = new CollectNameVisitor
  61 v2.start(node)
  62 var gram = v2.gram
  63
  64 if gram.prods.is_empty then
  65         print "Error: grammar with no production"
  66         exit(1)
  67 end
  68
  69 # Generate the LR automaton
  70
  71 var lr = gram.lr0
  72
  73 var conflitcs = new ArraySet[Production]
  74 for s in lr.states do for t, a in s.guarded_reduce do if a.length > 1 or s.guarded_shift.has_key(t) then
  75         for i in a do conflitcs.add(i.alt.prod)
  76 end
  77
  78 if not conflitcs.is_empty then
  79         print "Error: there is conflicts"
  80 end
  81
  82 if false then loop
  83 if conflitcs.is_empty then break
  84 print "Inline {conflitcs.join(" ")}"
  85 gram.inline(conflitcs)
  86 lr=gram.lr0
  87 end
  88
  89 # Output concrete grammar and LR automaton
  90
  91 var nbalts = 0
  92 for prod in gram.prods do nbalts += prod.alts.length
  93 print "Concrete grammar: {gram.prods.length} productions, {nbalts} alternatives (see {name}.concrete_grammar.txt)"
  94
  95 var pretty = gram.pretty
  96 var f = new OFStream.open("{name}.concrete_grammar.txt")
  97 f.write "// Concrete grammar of {name}\n"
  98 f.write pretty
  99 f.close
 100
 101 print "LR automaton: {lr.states.length} states (see {name}.lr.dot and {name}.lr.txt)"
 102 lr.to_dot("{name}.lr.dot")
 103 pretty = lr.pretty
 104 f = new OFStream.open("{name}.lr.txt")
 105 f.write "// LR automaton of {name}\n"
 106 f.write pretty
 107 f.close
 108
 109 # NFA and DFA
 110
 111 var nfa = v2.nfa
 112 print "NFA automaton: {nfa.states.length} states (see {name}.nfa.dot)"
 113 nfa.to_dot("{name}.nfa.dot")
 114
 115 var dfa = nfa.to_dfa
 116 if dfa.tags.has_key(dfa.start) then
 117         print "ERROR: Empty tokens {dfa.tags[dfa.start].join(" ")}"
 118 end
 119 dfa.solve_token_inclusion
 120 for s, tks in dfa.tags do
 121         if tks.length <= 1 then continue
 122         print "ERROR: Conflicting tokens: {tks.join(" ")}"
 123 end
 124 print "DFA automaton: {dfa.states.length} states (see {name}.dfa.dot)"
 125 dfa.to_dot("{name}.dfa.dot")
 126
 127 # Generate Nit code
 128
 129 print "Generate {name}_lexer.nit {name}_parser.nit {name}_test_parser.nit"
 130 dfa.gen_to_nit("{name}_lexer.nit", "{name}_parser")
 131 lr.gen_to_nit("{name}_parser.nit")
 132
 133 f = new OFStream.open("{name}_test_parser.nit")
 134 f.write """# Generated by nitcc for the language {{{name}}}
 135 import nitcc_runtime
 136 import {{{name}}}_lexer
 137 import {{{name}}}_parser
 138 class MyTest
 139         super TestParser
 140         redef fun name do return \"{{{name}}}\"
 141         redef fun new_lexer(text) do return new MyLexer(text)
 142         redef fun new_parser do return new MyParser
 143 end
 144 var t = new MyTest
 145 t.main
 146 """
 147 f.close