1"""Routine to "compile" a .py file to a .pyc (or .pyo) file. 2 3This module has intimate knowledge of the format of .pyc files. 4""" 5 6import __builtin__ 7import imp 8import marshal 9import os 10import sys 11import traceback 12 13MAGIC = imp.get_magic() 14 15__all__ = ["compile", "main", "PyCompileError"] 16 17 18class PyCompileError(Exception): 19 """Exception raised when an error occurs while attempting to 20 compile the file. 21 22 To raise this exception, use 23 24 raise PyCompileError(exc_type,exc_value,file[,msg]) 25 26 where 27 28 exc_type: exception type to be used in error message 29 type name can be accesses as class variable 30 'exc_type_name' 31 32 exc_value: exception value to be used in error message 33 can be accesses as class variable 'exc_value' 34 35 file: name of file being compiled to be used in error message 36 can be accesses as class variable 'file' 37 38 msg: string message to be written as error message 39 If no value is given, a default exception message will be given, 40 consistent with 'standard' py_compile output. 41 message (or default) can be accesses as class variable 'msg' 42 43 """ 44 45 def __init__(self, exc_type, exc_value, file, msg=''): 46 exc_type_name = exc_type.__name__ 47 if exc_type is SyntaxError: 48 tbtext = ''.join(traceback.format_exception_only(exc_type, exc_value)) 49 errmsg = tbtext.replace('File "<string>"', 'File "%s"' % file) 50 else: 51 errmsg = "Sorry: %s: %s" % (exc_type_name,exc_value) 52 53 Exception.__init__(self,msg or errmsg,exc_type_name,exc_value,file) 54 55 self.exc_type_name = exc_type_name 56 self.exc_value = exc_value 57 self.file = file 58 self.msg = msg or errmsg 59 60 def __str__(self): 61 return self.msg 62 63 64def wr_long(f, x): 65 """Internal; write a 32-bit int to a file in little-endian order.""" 66 f.write(chr( x & 0xff)) 67 f.write(chr((x >> 8) & 0xff)) 68 f.write(chr((x >> 16) & 0xff)) 69 f.write(chr((x >> 24) & 0xff)) 70 71def compile(file, cfile=None, dfile=None, doraise=False): 72 """Byte-compile one Python source file to Python bytecode. 73 74 Arguments: 75 76 file: source filename 77 cfile: target filename; defaults to source with 'c' or 'o' appended 78 ('c' normally, 'o' in optimizing mode, giving .pyc or .pyo) 79 dfile: purported filename; defaults to source (this is the filename 80 that will show up in error messages) 81 doraise: flag indicating whether or not an exception should be 82 raised when a compile error is found. If an exception 83 occurs and this flag is set to False, a string 84 indicating the nature of the exception will be printed, 85 and the function will return to the caller. If an 86 exception occurs and this flag is set to True, a 87 PyCompileError exception will be raised. 88 89 Note that it isn't necessary to byte-compile Python modules for 90 execution efficiency -- Python itself byte-compiles a module when 91 it is loaded, and if it can, writes out the bytecode to the 92 corresponding .pyc (or .pyo) file. 93 94 However, if a Python installation is shared between users, it is a 95 good idea to byte-compile all modules upon installation, since 96 other users may not be able to write in the source directories, 97 and thus they won't be able to write the .pyc/.pyo file, and then 98 they would be byte-compiling every module each time it is loaded. 99 This can slow down program start-up considerably. 100 101 See compileall.py for a script/module that uses this module to 102 byte-compile all installed files (or all files in selected 103 directories). 104 105 """ 106 with open(file, 'U') as f: 107 try: 108 timestamp = long(os.fstat(f.fileno()).st_mtime) 109 except AttributeError: 110 timestamp = long(os.stat(file).st_mtime) 111 codestring = f.read() 112 try: 113 codeobject = __builtin__.compile(codestring, dfile or file,'exec') 114 except Exception,err: 115 py_exc = PyCompileError(err.__class__,err.args,dfile or file) 116 if doraise: 117 raise py_exc 118 else: 119 sys.stderr.write(py_exc.msg + '\n') 120 return 121 if cfile is None: 122 cfile = file + (__debug__ and 'c' or 'o') 123 with open(cfile, 'wb') as fc: 124 fc.write('\0\0\0\0') 125 wr_long(fc, timestamp) 126 marshal.dump(codeobject, fc) 127 fc.flush() 128 fc.seek(0, 0) 129 fc.write(MAGIC) 130 131def main(args=None): 132 """Compile several source files. 133 134 The files named in 'args' (or on the command line, if 'args' is 135 not specified) are compiled and the resulting bytecode is cached 136 in the normal manner. This function does not search a directory 137 structure to locate source files; it only compiles files named 138 explicitly. If '-' is the only parameter in args, the list of 139 files is taken from standard input. 140 141 """ 142 if args is None: 143 args = sys.argv[1:] 144 rv = 0 145 if args == ['-']: 146 while True: 147 filename = sys.stdin.readline() 148 if not filename: 149 break 150 filename = filename.rstrip('\n') 151 try: 152 compile(filename, doraise=True) 153 except PyCompileError as error: 154 rv = 1 155 sys.stderr.write("%s\n" % error.msg) 156 except IOError as error: 157 rv = 1 158 sys.stderr.write("%s\n" % error) 159 else: 160 for filename in args: 161 try: 162 compile(filename, doraise=True) 163 except PyCompileError as error: 164 # return value to indicate at least one failure 165 rv = 1 166 sys.stderr.write(error.msg) 167 return rv 168 169if __name__ == "__main__": 170 sys.exit(main()) 171