eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 1 | #----------------------------------------------------------------- |
| 2 | # pycparser: c-to-c.py |
| 3 | # |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 4 | # Example of a C code generator from pycparser AST nodes, serving |
| 5 | # as a simplistic translator from C to AST and back to C. |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 6 | # Note: at this stage, the example is "alpha release" and considered |
| 7 | # experimental. Please file any bugs you find in the Issues page on pycparser's |
| 8 | # website. |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 9 | # |
| 10 | # Copyright (C) 2008-2011, Eli Bendersky |
eli.bendersky | 84a6a63 | 2011-04-29 09:00:43 +0300 | [diff] [blame] | 11 | # License: BSD |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 12 | #----------------------------------------------------------------- |
| 13 | from __future__ import print_function |
| 14 | import sys |
| 15 | |
| 16 | # This is not required if you've installed pycparser into |
| 17 | # your site-packages/ with setup.py |
| 18 | # |
| 19 | sys.path.insert(0, '..') |
| 20 | |
| 21 | from pycparser import c_parser, c_ast, parse_file |
| 22 | |
| 23 | |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 24 | class CGenerator(object): |
| 25 | """ Uses the same visitor pattern as c_ast.NodeVisitor, but modified to |
| 26 | return a value from each visit method, using string accumulation in |
| 27 | generic_visit. |
| 28 | """ |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 29 | def __init__(self): |
| 30 | self.output = '' |
| 31 | |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 32 | # Statements start with indentation of self.indent_level spaces, using |
| 33 | # the _make_indent method |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 34 | # |
| 35 | self.indent_level = 0 |
| 36 | |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 37 | def _make_indent(self): |
| 38 | return ' ' * self.indent_level |
| 39 | |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 40 | def visit(self, node): |
| 41 | method = 'visit_' + node.__class__.__name__ |
| 42 | return getattr(self, method, self.generic_visit)(node) |
| 43 | |
| 44 | def generic_visit(self, node): |
eli.bendersky | dcb859c | 2011-03-05 17:02:43 +0200 | [diff] [blame] | 45 | #~ print('generic:', type(node)) |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 46 | if node is None: |
| 47 | return '' |
| 48 | else: |
| 49 | return ''.join(self.visit(c) for c in node.children()) |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 50 | |
| 51 | def visit_Constant(self, n): |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 52 | return n.value |
| 53 | |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 54 | def visit_ID(self, n): |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 55 | return n.name |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 56 | |
| 57 | def visit_ArrayRef(self, n): |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 58 | arrref = self._parenthesize_unless_simple(n.name) |
| 59 | return arrref + '[' + self.visit(n.subscript) + ']' |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 60 | |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 61 | def visit_StructRef(self, n): |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 62 | sref = self._parenthesize_unless_simple(n.name) |
| 63 | return sref + n.type + self.visit(n.field) |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 64 | |
| 65 | def visit_FuncCall(self, n): |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 66 | fref = self._parenthesize_unless_simple(n.name) |
| 67 | return fref + '(' + self.visit(n.args) + ')' |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 68 | |
eli.bendersky | ae36e96 | 2011-02-27 08:25:05 +0200 | [diff] [blame] | 69 | def visit_UnaryOp(self, n): |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 70 | operand = self._parenthesize_unless_simple(n.expr) |
eli.bendersky | ae36e96 | 2011-02-27 08:25:05 +0200 | [diff] [blame] | 71 | if n.op == 'p++': |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 72 | return '%s++' % operand |
eli.bendersky | 8348a9d | 2011-05-26 07:01:43 +0300 | [diff] [blame^] | 73 | elif n.op == 'sizeof': |
| 74 | # Always parenthesize the argument of sizeof since it can be |
| 75 | # a name. |
| 76 | return 'sizeof(%s)' % self.visit(n.expr) |
eli.bendersky | ae36e96 | 2011-02-27 08:25:05 +0200 | [diff] [blame] | 77 | else: |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 78 | return '%s%s' % (n.op, operand) |
eli.bendersky | ae36e96 | 2011-02-27 08:25:05 +0200 | [diff] [blame] | 79 | |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 80 | def visit_BinaryOp(self, n): |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 81 | lval_str = self._parenthesize_if(n.left, |
| 82 | lambda d: not self._is_simple_node(d)) |
| 83 | rval_str = self._parenthesize_if(n.right, |
| 84 | lambda d: not self._is_simple_node(d)) |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 85 | return '%s %s %s' % (lval_str, n.op, rval_str) |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 86 | |
| 87 | def visit_Assignment(self, n): |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 88 | rval_str = self._parenthesize_if( |
| 89 | n.rvalue, |
| 90 | lambda n: isinstance(n, c_ast.Assignment)) |
| 91 | return '%s %s %s' % (self.visit(n.lvalue), n.op, rval_str) |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 92 | |
| 93 | def visit_IdentifierType(self, n): |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 94 | return ' '.join(n.names) |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 95 | |
eli.bendersky | abb96e6 | 2011-03-05 16:30:05 +0200 | [diff] [blame] | 96 | def visit_Decl(self, n, no_type=False): |
| 97 | # no_type is used when a Decl is part of a DeclList, where the type is |
| 98 | # explicitly only for the first delaration in a list. |
| 99 | # |
| 100 | s = n.name if no_type else self._generate_decl(n) |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 101 | if n.bitsize: s += ' : ' + self.visit(n.bitsize) |
eli.bendersky | dcb859c | 2011-03-05 17:02:43 +0200 | [diff] [blame] | 102 | if n.init: |
| 103 | if isinstance(n.init, c_ast.ExprList): |
| 104 | s += ' = {' + self.visit(n.init) + '}' |
| 105 | else: |
| 106 | s += ' = ' + self.visit(n.init) |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 107 | return s |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 108 | |
eli.bendersky | abb96e6 | 2011-03-05 16:30:05 +0200 | [diff] [blame] | 109 | def visit_DeclList(self, n): |
| 110 | s = self.visit(n.decls[0]) |
| 111 | if len(n.decls) > 1: |
| 112 | s += ', ' + ', '.join(self.visit_Decl(decl, no_type=True) |
| 113 | for decl in n.decls[1:]) |
| 114 | return s |
| 115 | |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 116 | def visit_Typedef(self, n): |
| 117 | s = '' |
| 118 | if n.storage: s += ' '.join(n.storage) + ' ' |
| 119 | s += self._generate_type(n.type) |
| 120 | return s |
| 121 | |
| 122 | def visit_Cast(self, n): |
eli.bendersky | 6ed80a6 | 2011-05-09 18:22:33 +0300 | [diff] [blame] | 123 | s = '(' + self._generate_type(n.to_type) + ')' |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 124 | return s + ' ' + self.visit(n.expr) |
| 125 | |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 126 | def visit_ExprList(self, n): |
eli.bendersky | 8e6c586 | 2011-05-20 12:35:08 +0300 | [diff] [blame] | 127 | visited_subexprs = [] |
| 128 | for expr in n.exprs: |
| 129 | if isinstance(expr, c_ast.ExprList): |
| 130 | visited_subexprs.append('{' + self.visit(expr) + '}') |
| 131 | else: |
| 132 | visited_subexprs.append(self.visit(expr)) |
| 133 | return ', '.join(visited_subexprs) |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 134 | |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 135 | def visit_Enum(self, n): |
| 136 | s = 'enum' |
| 137 | if n.name: s += ' ' + n.name |
| 138 | if n.values: |
| 139 | s += ' {' |
| 140 | for i, enumerator in enumerate(n.values.enumerators): |
| 141 | s += enumerator.name |
| 142 | if enumerator.value: |
| 143 | s += ' = ' + self.visit(enumerator.value) |
| 144 | if i != len(n.values.enumerators) - 1: |
| 145 | s += ', ' |
| 146 | s += '}' |
| 147 | return s |
| 148 | |
| 149 | def visit_Struct(self, n): |
| 150 | s = 'struct' |
| 151 | if n.name: s += ' ' + n.name |
| 152 | if n.decls: |
| 153 | s += ' { \n' |
| 154 | for decl in n.decls: |
| 155 | s += ' ' + self.visit(decl) + ';\n' |
| 156 | s += '}' |
| 157 | return s |
| 158 | |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 159 | def visit_FuncDef(self, n): |
| 160 | decl = self.visit(n.decl) |
| 161 | self.indent_level = 0 |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 162 | # The body is a Compound node |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 163 | body = self.visit(n.body) |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 164 | return decl + '\n' + body + '\n' |
| 165 | |
| 166 | def visit_FileAST(self, n): |
| 167 | s = '' |
| 168 | for ext in n.ext: |
| 169 | if isinstance(ext, c_ast.FuncDef): |
| 170 | s += self.visit(ext) |
| 171 | else: |
| 172 | s += self.visit(ext) + ';\n' |
| 173 | return s |
| 174 | |
| 175 | def visit_Compound(self, n): |
| 176 | s = self._make_indent() + '{\n' |
| 177 | self.indent_level += 2 |
eli.bendersky | cad1cfd | 2011-05-26 06:56:27 +0300 | [diff] [blame] | 178 | if n.block_items: |
| 179 | s += ''.join(self._generate_stmt(stmt) for stmt in n.block_items) |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 180 | self.indent_level -= 2 |
| 181 | s += self._make_indent() + '}\n' |
| 182 | return s |
| 183 | |
| 184 | def visit_ParamList(self, n): |
| 185 | return ', '.join(self.visit(param) for param in n.params) |
| 186 | |
| 187 | def visit_Return(self, n): |
| 188 | s = 'return' |
| 189 | if n.expr: s += ' ' + self.visit(n.expr) |
| 190 | return s + ';' |
| 191 | |
eli.bendersky | fc96e5e | 2011-03-04 09:51:23 +0200 | [diff] [blame] | 192 | def visit_Break(self, n): |
| 193 | return 'break;' |
| 194 | |
| 195 | def visit_Continue(self, n): |
| 196 | return 'continue;' |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 197 | |
| 198 | def visit_TernaryOp(self, n): |
| 199 | s = self.visit(n.cond) + ' ? ' |
| 200 | s += self.visit(n.iftrue) + ' : ' |
| 201 | s += self.visit(n.iffalse) |
| 202 | return s |
| 203 | |
eli.bendersky | e6ecb1a | 2011-03-05 10:58:46 +0200 | [diff] [blame] | 204 | def visit_If(self, n): |
| 205 | s = 'if (' |
| 206 | if n.cond: s += self.visit(n.cond) |
| 207 | s += ')\n' |
| 208 | s += self._generate_stmt(n.iftrue, add_indent=True) |
| 209 | if n.iffalse: |
| 210 | s += self._make_indent() + 'else\n' |
| 211 | s += self._generate_stmt(n.iffalse, add_indent=True) |
| 212 | return s |
| 213 | |
eli.bendersky | ae36e96 | 2011-02-27 08:25:05 +0200 | [diff] [blame] | 214 | def visit_For(self, n): |
| 215 | s = 'for (' |
| 216 | if n.init: s += self.visit(n.init) |
| 217 | s += ';' |
| 218 | if n.cond: s += ' ' + self.visit(n.cond) |
| 219 | s += ';' |
| 220 | if n.next: s += ' ' + self.visit(n.next) |
| 221 | s += ')\n' |
| 222 | s += self._generate_stmt(n.stmt, add_indent=True) |
| 223 | return s |
| 224 | |
eli.bendersky | fc96e5e | 2011-03-04 09:51:23 +0200 | [diff] [blame] | 225 | def visit_While(self, n): |
| 226 | s = 'while (' |
| 227 | if n.cond: s += self.visit(n.cond) |
| 228 | s += ')\n' |
| 229 | s += self._generate_stmt(n.stmt, add_indent=True) |
| 230 | return s |
| 231 | |
eli.bendersky | e6ecb1a | 2011-03-05 10:58:46 +0200 | [diff] [blame] | 232 | def visit_DoWhile(self, n): |
| 233 | s = 'do\n' |
| 234 | s += self._generate_stmt(n.stmt, add_indent=True) |
| 235 | s += self._make_indent() + 'while (' |
| 236 | if n.cond: s += self.visit(n.cond) |
| 237 | s += ');' |
| 238 | return s |
| 239 | |
eli.bendersky | abb96e6 | 2011-03-05 16:30:05 +0200 | [diff] [blame] | 240 | def visit_Switch(self, n): |
| 241 | s = 'switch (' + self.visit(n.cond) + ')\n' |
| 242 | s += self._generate_stmt(n.stmt, add_indent=True) |
| 243 | return s |
| 244 | |
| 245 | def visit_Case(self, n): |
| 246 | s = 'case ' + self.visit(n.expr) + ':\n' |
| 247 | s += self._generate_stmt(n.stmt, add_indent=True) |
| 248 | return s |
| 249 | |
| 250 | def visit_Default(self, n): |
| 251 | return 'default:\n' + self._generate_stmt(n.stmt, add_indent=True) |
| 252 | |
| 253 | def visit_Label(self, n): |
| 254 | return n.name + ':\n' + self._generate_stmt(n.stmt) |
| 255 | |
| 256 | def visit_Goto(self, n): |
| 257 | return 'goto ' + n.name + ';' |
| 258 | |
eli.bendersky | e6ecb1a | 2011-03-05 10:58:46 +0200 | [diff] [blame] | 259 | def visit_EllipsisParam(self, n): |
| 260 | return '...' |
| 261 | |
eli.bendersky | abb96e6 | 2011-03-05 16:30:05 +0200 | [diff] [blame] | 262 | def visit_Struct(self, n): |
| 263 | return self._generate_struct_union(n, 'struct') |
| 264 | |
eli.bendersky | 8e6c586 | 2011-05-20 12:35:08 +0300 | [diff] [blame] | 265 | def visit_Typename(self, n): |
| 266 | return self._generate_type(n.type) |
| 267 | |
eli.bendersky | abb96e6 | 2011-03-05 16:30:05 +0200 | [diff] [blame] | 268 | def visit_Union(self, n): |
| 269 | return self._generate_struct_union(n, 'union') |
| 270 | |
eli.bendersky | dcb859c | 2011-03-05 17:02:43 +0200 | [diff] [blame] | 271 | def visit_NamedInitializer(self, n): |
| 272 | s = '' |
| 273 | for name in n.name: |
| 274 | if isinstance(name, c_ast.ID): |
| 275 | s += '.' + name.name |
| 276 | elif isinstance(name, c_ast.Constant): |
| 277 | s += '[' + name.value + ']' |
| 278 | s += ' = ' + self.visit(n.expr) |
| 279 | return s |
| 280 | |
eli.bendersky | abb96e6 | 2011-03-05 16:30:05 +0200 | [diff] [blame] | 281 | def _generate_struct_union(self, n, name): |
| 282 | """ Generates code for structs and unions. name should be either |
| 283 | 'struct' or union. |
| 284 | """ |
eli.bendersky | dcb859c | 2011-03-05 17:02:43 +0200 | [diff] [blame] | 285 | s = name + ' ' + (n.name or '') |
| 286 | if n.decls: |
| 287 | s += '\n' |
| 288 | s += self._make_indent() |
| 289 | self.indent_level += 2 |
| 290 | s += '{\n' |
| 291 | for decl in n.decls: |
| 292 | s += self._generate_stmt(decl) |
| 293 | self.indent_level -= 2 |
| 294 | s += self._make_indent() + '}' |
eli.bendersky | abb96e6 | 2011-03-05 16:30:05 +0200 | [diff] [blame] | 295 | return s |
| 296 | |
eli.bendersky | ae36e96 | 2011-02-27 08:25:05 +0200 | [diff] [blame] | 297 | def _generate_stmt(self, n, add_indent=False): |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 298 | """ Generation from a statement node. This method exists as a wrapper |
| 299 | for individual visit_* methods to handle different treatment of |
| 300 | some statements in this context. |
| 301 | """ |
| 302 | typ = type(n) |
eli.bendersky | ae36e96 | 2011-02-27 08:25:05 +0200 | [diff] [blame] | 303 | if add_indent: self.indent_level += 2 |
eli.bendersky | fc96e5e | 2011-03-04 09:51:23 +0200 | [diff] [blame] | 304 | indent = self._make_indent() |
eli.bendersky | ae36e96 | 2011-02-27 08:25:05 +0200 | [diff] [blame] | 305 | if add_indent: self.indent_level -= 2 |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 306 | |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 307 | if typ in ( |
| 308 | c_ast.Decl, c_ast.Assignment, c_ast.Cast, c_ast.UnaryOp, |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 309 | c_ast.BinaryOp, c_ast.TernaryOp, c_ast.FuncCall, c_ast.ArrayRef, |
| 310 | c_ast.StructRef): |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 311 | # These can also appear in an expression context so no semicolon |
| 312 | # is added to them automatically |
| 313 | # |
eli.bendersky | fc96e5e | 2011-03-04 09:51:23 +0200 | [diff] [blame] | 314 | return indent + self.visit(n) + ';\n' |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 315 | elif typ in (c_ast.Compound,): |
| 316 | # No extra indentation required before the opening brace of a |
| 317 | # compound - because it consists of multiple lines it has to |
| 318 | # compute its own indentation. |
| 319 | # |
eli.bendersky | ae36e96 | 2011-02-27 08:25:05 +0200 | [diff] [blame] | 320 | return self.visit(n) |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 321 | else: |
eli.bendersky | fc96e5e | 2011-03-04 09:51:23 +0200 | [diff] [blame] | 322 | return indent + self.visit(n) + '\n' |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 323 | |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 324 | def _generate_decl(self, n): |
| 325 | """ Generation from a Decl node. |
| 326 | """ |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 327 | s = '' |
| 328 | if n.funcspec: s = ' '.join(n.funcspec) + ' ' |
| 329 | if n.storage: s += ' '.join(n.storage) + ' ' |
| 330 | s += self._generate_type(n.type) |
| 331 | return s |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 332 | |
| 333 | def _generate_type(self, n, modifiers=[]): |
| 334 | """ Recursive generation from a type node. n is the type node. |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 335 | modifiers collects the PtrDecl, ArrayDecl and FuncDecl modifiers |
| 336 | encountered on the way down to a TypeDecl, to allow proper |
| 337 | generation from it. |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 338 | """ |
| 339 | typ = type(n) |
| 340 | #~ print(n, modifiers) |
| 341 | |
| 342 | if typ == c_ast.TypeDecl: |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 343 | s = '' |
| 344 | if n.quals: s += ' '.join(n.quals) + ' ' |
| 345 | s += self.visit(n.type) |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 346 | |
| 347 | nstr = n.declname if n.declname else '' |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 348 | # Resolve modifiers. |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 349 | # Wrap in parens to distinguish pointer to array and pointer to |
| 350 | # function syntax. |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 351 | # |
| 352 | for i, modifier in enumerate(modifiers): |
| 353 | if isinstance(modifier, c_ast.ArrayDecl): |
| 354 | if (i != 0 and isinstance(modifiers[i - 1], c_ast.PtrDecl)): |
| 355 | nstr = '(' + nstr + ')' |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 356 | nstr += '[' + self.visit(modifier.dim) + ']' |
| 357 | elif isinstance(modifier, c_ast.FuncDecl): |
| 358 | if (i != 0 and isinstance(modifiers[i - 1], c_ast.PtrDecl)): |
| 359 | nstr = '(' + nstr + ')' |
| 360 | nstr += '(' + self.visit(modifier.args) + ')' |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 361 | elif isinstance(modifier, c_ast.PtrDecl): |
| 362 | nstr = '*' + nstr |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 363 | s += ' ' + nstr |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 364 | return s |
eli.bendersky | 6ed80a6 | 2011-05-09 18:22:33 +0300 | [diff] [blame] | 365 | elif typ == c_ast.Decl: |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 366 | return self._generate_decl(n.type) |
eli.bendersky | 6ed80a6 | 2011-05-09 18:22:33 +0300 | [diff] [blame] | 367 | elif typ == c_ast.Typename: |
| 368 | return self._generate_type(n.type) |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 369 | elif typ == c_ast.IdentifierType: |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 370 | return ' '.join(n.names) + ' ' |
| 371 | elif typ in (c_ast.ArrayDecl, c_ast.PtrDecl, c_ast.FuncDecl): |
| 372 | return self._generate_type(n.type, modifiers + [n]) |
eli.bendersky | abb96e6 | 2011-03-05 16:30:05 +0200 | [diff] [blame] | 373 | else: |
| 374 | return self.visit(n) |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 375 | |
eli.bendersky | 724b1cc | 2011-03-05 10:45:08 +0200 | [diff] [blame] | 376 | def _parenthesize_if(self, n, condition): |
| 377 | """ Visits 'n' and returns its string representation, parenthesized |
| 378 | if the condition function applied to the node returns True. |
| 379 | """ |
| 380 | s = self.visit(n) |
| 381 | if condition(n): |
| 382 | return '(' + s + ')' |
| 383 | else: |
| 384 | return s |
| 385 | |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 386 | def _parenthesize_unless_simple(self, n): |
| 387 | """ Common use case for _parenthesize_if |
| 388 | """ |
| 389 | return self._parenthesize_if(n, lambda d: not self._is_simple_node(d)) |
| 390 | |
| 391 | def _is_simple_node(self, n): |
| 392 | """ Returns True for nodes that are "simple" - i.e. nodes that always |
| 393 | have higher precedence than operators. |
| 394 | """ |
| 395 | return isinstance(n,( c_ast.Constant, c_ast.ID, c_ast.ArrayRef, |
| 396 | c_ast.StructRef, c_ast.FuncCall)) |
| 397 | |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 398 | |
| 399 | def translate_to_c(filename): |
| 400 | ast = parse_file(filename, use_cpp=True) |
| 401 | generator = CGenerator() |
eli.bendersky | afcfaac | 2011-02-25 16:46:01 +0200 | [diff] [blame] | 402 | print(generator.visit(ast)) |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 403 | |
| 404 | |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 405 | def zz_test_translate(): |
| 406 | # internal use |
eli.bendersky | 8e6c586 | 2011-05-20 12:35:08 +0300 | [diff] [blame] | 407 | src = r''' |
eli.bendersky | 8348a9d | 2011-05-26 07:01:43 +0300 | [diff] [blame^] | 408 | int main(void) |
| 409 | { |
| 410 | unsigned size; |
| 411 | size = sizeof(size); |
| 412 | return 0; |
| 413 | } |
| 414 | ''' |
eli.bendersky | 8e6c586 | 2011-05-20 12:35:08 +0300 | [diff] [blame] | 415 | parser = c_parser.CParser() |
| 416 | ast = parser.parse(src) |
| 417 | ast.show() |
| 418 | generator = CGenerator() |
| 419 | |
| 420 | print(generator.visit(ast)) |
| 421 | |
| 422 | # tracing the generator for debugging |
| 423 | #~ import trace |
| 424 | #~ tr = trace.Trace(countcallers=1) |
| 425 | #~ tr.runfunc(generator.visit, ast) |
| 426 | #~ tr.results().write_results() |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 427 | |
| 428 | |
| 429 | #------------------------------------------------------------------------------ |
| 430 | if __name__ == "__main__": |
eli.bendersky | 6ed80a6 | 2011-05-09 18:22:33 +0300 | [diff] [blame] | 431 | zz_test_translate() |
eli.bendersky | b36f5bb | 2011-03-06 07:22:33 +0200 | [diff] [blame] | 432 | if len(sys.argv) > 1: |
| 433 | translate_to_c(sys.argv[1]) |
| 434 | else: |
eli.bendersky | d5ba345 | 2011-02-18 21:32:47 +0200 | [diff] [blame] | 435 | print("Please provide a filename as argument") |
eli.bendersky | 3ae9f7a | 2011-02-27 07:19:41 +0200 | [diff] [blame] | 436 | |