diff options
Diffstat (limited to 'Lib/compiler')
| -rw-r--r-- | Lib/compiler/pyassem.py | 437 | ||||
| -rw-r--r-- | Lib/compiler/pycodegen.py | 722 |
2 files changed, 623 insertions, 536 deletions
diff --git a/Lib/compiler/pyassem.py b/Lib/compiler/pyassem.py new file mode 100644 index 0000000..047836b --- /dev/null +++ b/Lib/compiler/pyassem.py @@ -0,0 +1,437 @@ +"""Assembler for Python bytecode + +The new module is used to create the code object. The following +attribute definitions are included from the reference manual: + +co_name gives the function name +co_argcount is the number of positional arguments (including + arguments with default values) +co_nlocals is the number of local variables used by the function + (including arguments) +co_varnames is a tuple containing the names of the local variables + (starting with the argument names) +co_code is a string representing the sequence of bytecode instructions +co_consts is a tuple containing the literals used by the bytecode +co_names is a tuple containing the names used by the bytecode +co_filename is the filename from which the code was compiled +co_firstlineno is the first line number of the function +co_lnotab is a string encoding the mapping from byte code offsets + to line numbers. see LineAddrTable below. +co_stacksize is the required stack size (including local variables) +co_flags is an integer encoding a number of flags for the + interpreter. There are four flags: + CO_OPTIMIZED -- uses load fast + CO_NEWLOCALS -- everything? + CO_VARARGS -- use *args + CO_VARKEYWORDS -- uses **args + +If a code object represents a function, the first item in co_consts is +the documentation string of the function, or None if undefined. +""" + +import sys +import dis +import new +import string + +import misc + +# flags for code objects +CO_OPTIMIZED = 0x0001 +CO_NEWLOCALS = 0x0002 +CO_VARARGS = 0x0004 +CO_VARKEYWORDS = 0x0008 + +class PyAssembler: + """Creates Python code objects + """ + + # XXX this class needs to major refactoring + + def __init__(self, args=(), name='?', filename='<?>', + docstring=None): + # XXX why is the default value for flags 3? + self.insts = [] + # used by makeCodeObject + self.argcount = len(args) + self.code = '' + self.consts = [docstring] + self.filename = filename + self.flags = CO_NEWLOCALS + self.name = name + self.names = [] + self.varnames = list(args) or [] + # lnotab support + self.firstlineno = 0 + self.lastlineno = 0 + self.last_addr = 0 + self.lnotab = '' + + def __repr__(self): + return "<bytecode: %d instrs>" % len(self.insts) + + def setFlags(self, val): + """XXX for module's function""" + self.flags = val + + def setOptimized(self): + self.flags = self.flags | CO_OPTIMIZED + + def setVarArgs(self): + self.flags = self.flags | CO_VARARGS + + def setKWArgs(self): + self.flags = self.flags | CO_VARKEYWORDS + + def getCurInst(self): + return len(self.insts) + + def getNextInst(self): + return len(self.insts) + 1 + + def dump(self, io=sys.stdout): + i = 0 + for inst in self.insts: + if inst[0] == 'SET_LINENO': + io.write("\n") + io.write(" %3d " % i) + if len(inst) == 1: + io.write("%s\n" % inst) + else: + io.write("%-15.15s\t%s\n" % inst) + i = i + 1 + + def makeCodeObject(self): + """Make a Python code object + + This creates a Python code object using the new module. This + seems simpler than reverse-engineering the way marshal dumps + code objects into .pyc files. One of the key difficulties is + figuring out how to layout references to code objects that + appear on the VM stack; e.g. + 3 SET_LINENO 1 + 6 LOAD_CONST 0 (<code object fact at 8115878 [...] + 9 MAKE_FUNCTION 0 + 12 STORE_NAME 0 (fact) + """ + + self._findOffsets() + lnotab = LineAddrTable() + for t in self.insts: + opname = t[0] + if len(t) == 1: + lnotab.addCode(chr(self.opnum[opname])) + elif len(t) == 2: + oparg = self._convertArg(opname, t[1]) + if opname == 'SET_LINENO': + lnotab.nextLine(oparg) + try: + hi, lo = divmod(oparg, 256) + except TypeError: + raise TypeError, "untranslated arg: %s, %s" % (opname, oparg) + lnotab.addCode(chr(self.opnum[opname]) + chr(lo) + + chr(hi)) + # why is a module a special case? + if self.flags == 0: + nlocals = 0 + else: + nlocals = len(self.varnames) + # XXX danger! can't pass through here twice + if self.flags & CO_VARKEYWORDS: + self.argcount = self.argcount - 1 + stacksize = findDepth(self.insts) + co = new.code(self.argcount, nlocals, stacksize, + self.flags, lnotab.getCode(), self._getConsts(), + tuple(self.names), tuple(self.varnames), + self.filename, self.name, self.firstlineno, + lnotab.getTable()) + return co + + def _getConsts(self): + """Return a tuple for the const slot of a code object + + Converts PythonVMCode objects to code objects + """ + l = [] + for elt in self.consts: + # XXX might be clearer to just as isinstance(CodeGen) + if hasattr(elt, 'asConst'): + l.append(elt.asConst()) + else: + l.append(elt) + return tuple(l) + + def _findOffsets(self): + """Find offsets for use in resolving StackRefs""" + self.offsets = [] + cur = 0 + for t in self.insts: + self.offsets.append(cur) + l = len(t) + if l == 1: + cur = cur + 1 + elif l == 2: + cur = cur + 3 + arg = t[1] + # XXX this is a total hack: for a reference used + # multiple times, we create a list of offsets and + # expect that we when we pass through the code again + # to actually generate the offsets, we'll pass in the + # same order. + if isinstance(arg, StackRef): + try: + arg.__offset.append(cur) + except AttributeError: + arg.__offset = [cur] + + def _convertArg(self, op, arg): + """Convert the string representation of an arg to a number + + The specific handling depends on the opcode. + + XXX This first implementation isn't going to be very + efficient. + """ + if op == 'SET_LINENO': + return arg + if op == 'LOAD_CONST': + return self._lookupName(arg, self.consts) + if op in self.localOps: + # make sure it's in self.names, but use the bytecode offset + self._lookupName(arg, self.names) + return self._lookupName(arg, self.varnames) + if op in self.globalOps: + return self._lookupName(arg, self.names) + if op in self.nameOps: + return self._lookupName(arg, self.names) + if op == 'COMPARE_OP': + return self.cmp_op.index(arg) + if self.hasjrel.has_elt(op): + offset = arg.__offset[0] + del arg.__offset[0] + return self.offsets[arg.resolve()] - offset + if self.hasjabs.has_elt(op): + return self.offsets[arg.resolve()] + return arg + + nameOps = ('STORE_NAME', 'IMPORT_NAME', 'IMPORT_FROM', + 'STORE_ATTR', 'LOAD_ATTR', 'LOAD_NAME', 'DELETE_NAME') + localOps = ('LOAD_FAST', 'STORE_FAST', 'DELETE_FAST') + globalOps = ('LOAD_GLOBAL', 'STORE_GLOBAL', 'DELETE_GLOBAL') + + def _lookupName(self, name, list, list2=None): + """Return index of name in list, appending if necessary + + Yicky hack: Second list can be used for lookup of local names + where the name needs to be added to varnames and names. + """ + if name in list: + return list.index(name) + else: + end = len(list) + list.append(name) + if list2 is not None: + list2.append(name) + return end + + # Convert some stuff from the dis module for local use + + cmp_op = list(dis.cmp_op) + hasjrel = misc.Set() + for i in dis.hasjrel: + hasjrel.add(dis.opname[i]) + hasjabs = misc.Set() + for i in dis.hasjabs: + hasjabs.add(dis.opname[i]) + + opnum = {} + for num in range(len(dis.opname)): + opnum[dis.opname[num]] = num + + # this version of emit + arbitrary hooks might work, but it's damn + # messy. + + def emit(self, *args): + self._emitDispatch(args[0], args[1:]) + self.insts.append(args) + + def _emitDispatch(self, type, args): + for func in self._emit_hooks.get(type, []): + func(self, args) + + _emit_hooks = {} + +class LineAddrTable: + """lnotab + + This class builds the lnotab, which is undocumented but described + by com_set_lineno in compile.c. Here's an attempt at explanation: + + For each SET_LINENO instruction after the first one, two bytes are + added to lnotab. (In some cases, multiple two-byte entries are + added.) The first byte is the distance in bytes between the + instruction for the last SET_LINENO and the current SET_LINENO. + The second byte is offset in line numbers. If either offset is + greater than 255, multiple two-byte entries are added -- one entry + for each factor of 255. + """ + + def __init__(self): + self.code = [] + self.codeOffset = 0 + self.firstline = 0 + self.lastline = 0 + self.lastoff = 0 + self.lnotab = [] + + def addCode(self, code): + self.code.append(code) + self.codeOffset = self.codeOffset + len(code) + + def nextLine(self, lineno): + if self.firstline == 0: + self.firstline = lineno + self.lastline = lineno + else: + # compute deltas + addr = self.codeOffset - self.lastoff + line = lineno - self.lastline + while addr > 0 or line > 0: + # write the values in 1-byte chunks that sum + # to desired value + trunc_addr = addr + trunc_line = line + if trunc_addr > 255: + trunc_addr = 255 + if trunc_line > 255: + trunc_line = 255 + self.lnotab.append(trunc_addr) + self.lnotab.append(trunc_line) + addr = addr - trunc_addr + line = line - trunc_line + self.lastline = lineno + self.lastoff = self.codeOffset + + def getCode(self): + return string.join(self.code, '') + + def getTable(self): + return string.join(map(chr, self.lnotab), '') + +class StackRef: + """Manage stack locations for jumps, loops, etc.""" + count = 0 + + def __init__(self, id=None, val=None): + if id is None: + id = StackRef.count + StackRef.count = StackRef.count + 1 + self.id = id + self.val = val + + def __repr__(self): + if self.val: + return "StackRef(val=%d)" % self.val + else: + return "StackRef(id=%d)" % self.id + + def bind(self, inst): + self.val = inst + + def resolve(self): + if self.val is None: + print "UNRESOLVE REF", self + return 0 + return self.val + +class StackDepthTracker: + # XXX need to keep track of stack depth on jumps + + def findDepth(self, insts): + depth = 0 + maxDepth = 0 + for i in insts: + opname = i[0] + delta = self.effect.get(opname, 0) + if delta > 1: + depth = depth + delta + elif delta < 0: + if depth > maxDepth: + maxDepth = depth + depth = depth + delta + else: + if depth > maxDepth: + maxDepth = depth + # now check patterns + for pat, delta in self.patterns: + if opname[:len(pat)] == pat: + depth = depth + delta + break + # if we still haven't found a match + if delta == 0: + meth = getattr(self, opname) + depth = depth + meth(i[1]) + if depth < 0: + depth = 0 + return maxDepth + + effect = { + 'POP_TOP': -1, + 'DUP_TOP': 1, + 'SLICE+1': -1, + 'SLICE+2': -1, + 'SLICE+3': -2, + 'STORE_SLICE+0': -1, + 'STORE_SLICE+1': -2, + 'STORE_SLICE+2': -2, + 'STORE_SLICE+3': -3, + 'DELETE_SLICE+0': -1, + 'DELETE_SLICE+1': -2, + 'DELETE_SLICE+2': -2, + 'DELETE_SLICE+3': -3, + 'STORE_SUBSCR': -3, + 'DELETE_SUBSCR': -2, + # PRINT_EXPR? + 'PRINT_ITEM': -1, + 'LOAD_LOCALS': 1, + 'RETURN_VALUE': -1, + 'EXEC_STMT': -2, + 'BUILD_CLASS': -2, + 'STORE_NAME': -1, + 'STORE_ATTR': -2, + 'DELETE_ATTR': -1, + 'STORE_GLOBAL': -1, + 'BUILD_MAP': 1, + 'COMPARE_OP': -1, + 'STORE_FAST': -1, + } + # use pattern match + patterns = [ + ('BINARY_', -1), + ('LOAD_', 1), + ('IMPORT_', 1), + ] + # special cases + + #: UNPACK_TUPLE, UNPACK_LIST, BUILD_TUPLE, + # BUILD_LIST, CALL_FUNCTION, MAKE_FUNCTION, BUILD_SLICE + def UNPACK_TUPLE(self, count): + return count + def UNPACK_LIST(self, count): + return count + def BUILD_TUPLE(self, count): + return -count + def BUILD_LIST(self, count): + return -count + def CALL_FUNCTION(self, argc): + hi, lo = divmod(argc, 256) + return lo + hi * 2 + def MAKE_FUNCTION(self, argc): + return -argc + def BUILD_SLICE(self, argc): + if argc == 2: + return -1 + elif argc == 3: + return -2 + +findDepth = StackDepthTracker().findDepth diff --git a/Lib/compiler/pycodegen.py b/Lib/compiler/pycodegen.py index 8599e6b..ac93348 100644 --- a/Lib/compiler/pycodegen.py +++ b/Lib/compiler/pycodegen.py @@ -6,6 +6,7 @@ a generic tool and CodeGenerator as a specific tool. """ from p2c import transformer, ast +from pyassem import StackRef, PyAssembler import dis import misc import marshal @@ -149,14 +150,25 @@ class ExampleASTVisitor(ASTVisitor): print class CodeGenerator: - # XXX this should be combined with PythonVMCode. there is no - # clear way to split the functionality into two classes. + """TODO + + EmptyNode + Exec + Invert + LeftShift + Power + RightShift + Sliceobj + Tryexcept + Tryfinally + """ OPTIMIZED = 1 + # XXX should clean up initialization and generateXXX funcs def __init__(self, filename="<?>"): self.filename = filename - self.code = PythonVMCode() + self.code = PyAssembler() self.code.setFlags(0) self.locals = misc.Stack() self.loops = misc.Stack() @@ -164,11 +176,15 @@ class CodeGenerator: self.curStack = 0 self.maxStack = 0 + def emit(self, *args): + # XXX could just use self.emit = self.code.emit + apply(self.code.emit, args) + def _generateFunctionOrLambdaCode(self, func): self.name = func.name self.filename = filename args = func.argnames - self.code = PythonVMCode(args=args, name=func.name, + self.code = PyAssembler(args=args, name=func.name, filename=filename) self.namespace = self.OPTIMIZED if func.varargs: @@ -177,38 +193,34 @@ class CodeGenerator: self.code.setKWArgs() lnf = walk(func.code, LocalNameFinder(args), 0) self.locals.push(lnf.getLocals()) - self.code.setLineNo(func.lineno) + self.emit('SET_LINENO', func.lineno) walk(func.code, self) def generateFunctionCode(self, func): """Generate code for a function body""" self._generateFunctionOrLambdaCode(func) - self.code.emit('LOAD_CONST', None) - self.code.emit('RETURN_VALUE') + self.emit('LOAD_CONST', None) + self.emit('RETURN_VALUE') def generateLambdaCode(self, func): self._generateFunctionOrLambdaCode(func) - self.code.emit('RETURN_VALUE') + self.emit('RETURN_VALUE') def generateClassCode(self, klass): - self.code = PythonVMCode(name=klass.name, + self.code = PyAssembler(name=klass.name, filename=filename) - self.code.setLineNo(klass.lineno) + self.emit('SET_LINENO', klass.lineno) lnf = walk(klass.code, LocalNameFinder(), 0) self.locals.push(lnf.getLocals()) walk(klass.code, self) - self.code.emit('LOAD_LOCALS') - self.code.emit('RETURN_VALUE') + self.emit('LOAD_LOCALS') + self.emit('RETURN_VALUE') - def emit(self): - """Create a Python code object - - XXX It is confusing that this method isn't related to the - method named emit in the PythonVMCode. - """ + def asConst(self): + """Create a Python code object.""" if self.namespace == self.OPTIMIZED: self.code.setOptimized() - return self.code.makeCodeObject(self.maxStack) + return self.code.makeCodeObject() def isLocalName(self, name): return self.locals.top().has_elt(name) @@ -216,11 +228,11 @@ class CodeGenerator: def _nameOp(self, prefix, name): if self.isLocalName(name): if self.namespace == self.OPTIMIZED: - self.code.emit(prefix + '_FAST', name) + self.emit(prefix + '_FAST', name) else: - self.code.emit(prefix + '_NAME', name) + self.emit(prefix + '_NAME', name) else: - self.code.emit(prefix + '_GLOBAL', name) + self.emit(prefix + '_GLOBAL', name) def storeName(self, name): self._nameOp('STORE', name) @@ -231,21 +243,6 @@ class CodeGenerator: def delName(self, name): self._nameOp('DELETE', name) - def push(self, n): - self.curStack = self.curStack + n - if self.curStack > self.maxStack: - self.maxStack = self.curStack - - def pop(self, n): - if n >= self.curStack: - self.curStack = self.curStack - n - else: - self.curStack = 0 - - def assertStackEmpty(self): - if self.curStack != 0: - print "warning: stack should be empty" - def visitNULL(self, node): """Method exists only to stop warning in -v mode""" pass @@ -255,46 +252,45 @@ class CodeGenerator: def visitDiscard(self, node): self.visit(node.expr) - self.code.emit('POP_TOP') - self.pop(1) + self.emit('POP_TOP') return 1 def visitPass(self, node): - self.code.setLineNo(node.lineno) + self.emit('SET_LINENO', node.lineno) def visitModule(self, node): lnf = walk(node.node, LocalNameFinder(), 0) self.locals.push(lnf.getLocals()) self.visit(node.node) - self.code.emit('LOAD_CONST', None) - self.code.emit('RETURN_VALUE') + self.emit('LOAD_CONST', None) + self.emit('RETURN_VALUE') return 1 def visitImport(self, node): - self.code.setLineNo(node.lineno) + self.emit('SET_LINENO', node.lineno) for name in node.names: - self.code.emit('IMPORT_NAME', name) + self.emit('IMPORT_NAME', name) self.storeName(name) def visitFrom(self, node): - self.code.setLineNo(node.lineno) - self.code.emit('IMPORT_NAME', node.modname) + self.emit('SET_LINENO', node.lineno) + self.emit('IMPORT_NAME', node.modname) for name in node.names: - self.code.emit('IMPORT_FROM', name) - self.code.emit('POP_TOP') + self.emit('IMPORT_FROM', name) + self.emit('POP_TOP') def visitClassdef(self, node): - self.code.emit('SET_LINENO', node.lineno) - self.code.emit('LOAD_CONST', node.name) + self.emit('SET_LINENO', node.lineno) + self.emit('LOAD_CONST', node.name) for base in node.bases: self.visit(base) - self.code.emit('BUILD_TUPLE', len(node.bases)) + self.emit('BUILD_TUPLE', len(node.bases)) classBody = CodeGenerator(self.filename) classBody.generateClassCode(node) - self.code.emit('LOAD_CONST', classBody) - self.code.emit('MAKE_FUNCTION', 0) - self.code.emit('CALL_FUNCTION', 0) - self.code.emit('BUILD_CLASS') + self.emit('LOAD_CONST', classBody) + self.emit('MAKE_FUNCTION', 0) + self.emit('CALL_FUNCTION', 0) + self.emit('BUILD_CLASS') self.storeName(node.name) return 1 @@ -302,11 +298,11 @@ class CodeGenerator: """Code common to Function and Lambda nodes""" codeBody = CodeGenerator(self.filename) getattr(codeBody, 'generate%sCode' % kind)(node) - self.code.setLineNo(node.lineno) + self.emit('SET_LINENO', node.lineno) for default in node.defaults: self.visit(default) - self.code.emit('LOAD_CONST', codeBody) - self.code.emit('MAKE_FUNCTION', len(node.defaults)) + self.emit('LOAD_CONST', codeBody) + self.emit('MAKE_FUNCTION', len(node.defaults)) def visitFunction(self, node): self._visitFuncOrLambda(node, 'Function') @@ -323,7 +319,7 @@ class CodeGenerator: pos = 0 kw = 0 if hasattr(node, 'lineno'): - self.code.emit('SET_LINENO', node.lineno) + self.emit('SET_LINENO', node.lineno) self.visit(node.node) for arg in node.args: self.visit(arg) @@ -331,11 +327,11 @@ class CodeGenerator: kw = kw + 1 else: pos = pos + 1 - self.code.callFunction(kw << 8 | pos) + self.emit('CALL_FUNCTION', kw << 8 | pos) return 1 def visitKeyword(self, node): - self.code.emit('LOAD_CONST', node.name) + self.emit('LOAD_CONST', node.name) self.visit(node.expr) return 1 @@ -343,17 +339,17 @@ class CodeGenerator: after = StackRef() for test, suite in node.tests: if hasattr(test, 'lineno'): - self.code.setLineNo(test.lineno) + self.emit('SET_LINENO', test.lineno) else: print "warning", "no line number" self.visit(test) dest = StackRef() - self.code.jumpIfFalse(dest) - self.code.popTop() + self.emit('JUMP_IF_FALSE', dest) + self.emit('POP_TOP') self.visit(suite) - self.code.jumpForward(after) + self.emit('JUMP_FORWARD', after) dest.bind(self.code.getCurInst()) - self.code.popTop() + self.emit('POP_TOP') if node.else_: self.visit(node.else_) after.bind(self.code.getCurInst()) @@ -362,7 +358,7 @@ class CodeGenerator: def startLoop(self): l = Loop() self.loops.push(l) - self.code.emit('SETUP_LOOP', l.extentAnchor) + self.emit('SETUP_LOOP', l.extentAnchor) return l def finishLoop(self): @@ -374,42 +370,41 @@ class CodeGenerator: # three refs needed anchor = StackRef() - self.code.emit('SET_LINENO', node.lineno) + self.emit('SET_LINENO', node.lineno) l = self.startLoop() self.visit(node.list) self.visit(ast.Const(0)) l.startAnchor.bind(self.code.getCurInst()) - self.code.setLineNo(node.lineno) - self.code.emit('FOR_LOOP', anchor) - self.push(1) + self.emit('SET_LINENO', node.lineno) + self.emit('FOR_LOOP', anchor) self.visit(node.assign) self.visit(node.body) - self.code.emit('JUMP_ABSOLUTE', l.startAnchor) + self.emit('JUMP_ABSOLUTE', l.startAnchor) anchor.bind(self.code.getCurInst()) - self.code.emit('POP_BLOCK') + self.emit('POP_BLOCK') if node.else_: self.visit(node.else_) self.finishLoop() return 1 def visitWhile(self, node): - self.code.emit('SET_LINENO', node.lineno) + self.emit('SET_LINENO', node.lineno) l = self.startLoop() if node.else_: lElse = StackRef() else: lElse = l.breakAnchor l.startAnchor.bind(self.code.getCurInst()) - self.code.emit('SET_LINENO', node.test.lineno) + self.emit('SET_LINENO', node.test.lineno) self.visit(node.test) - self.code.emit('JUMP_IF_FALSE', lElse) - self.code.emit('POP_TOP') + self.emit('JUMP_IF_FALSE', lElse) + self.emit('POP_TOP') self.visit(node.body) - self.code.emit('JUMP_ABSOLUTE', l.startAnchor) + self.emit('JUMP_ABSOLUTE', l.startAnchor) # note that lElse may be an alias for l.breakAnchor lElse.bind(self.code.getCurInst()) - self.code.emit('POP_TOP') - self.code.emit('POP_BLOCK') + self.emit('POP_TOP') + self.emit('POP_BLOCK') if node.else_: self.visit(node.else_) self.finishLoop() @@ -418,16 +413,15 @@ class CodeGenerator: def visitBreak(self, node): if not self.loops: raise SyntaxError, "'break' outside loop" - self.code.emit('SET_LINENO', node.lineno) - self.code.emit('BREAK_LOOP') + self.emit('SET_LINENO', node.lineno) + self.emit('BREAK_LOOP') def visitContinue(self, node): if not self.loops: raise SyntaxError, "'continue' outside loop" l = self.loops.top() - self.code.emit('SET_LINENO', node.lineno) - self.code.emit('JUMP_ABSOLUTE', l.startAnchor) - + self.emit('SET_LINENO', node.lineno) + self.emit('JUMP_ABSOLUTE', l.startAnchor) def visitCompare(self, node): """Comment from compile.c follows: @@ -470,44 +464,42 @@ class CodeGenerator: for op, code in node.ops[:-1]: # emit every comparison except the last self.visit(code) - self.code.dupTop() - self.code.rotThree() - self.code.compareOp(op) + self.emit('DUP_TOP') + self.emit('ROT_THREE') + self.emit('COMPARE_OP', op) # dupTop and compareOp cancel stack effect - self.code.jumpIfFalse(l1) - self.code.popTop() - self.pop(1) + self.emit('JUMP_IF_FALSE', l1) + self.emit('POP_TOP') if node.ops: # emit the last comparison op, code = node.ops[-1] self.visit(code) - self.code.compareOp(op) - self.pop(1) + self.emit('COMPARE_OP', op) if len(node.ops) > 1: - self.code.jumpForward(l2) + self.emit('JUMP_FORWARD', l2) l1.bind(self.code.getCurInst()) - self.code.rotTwo() - self.code.popTop() - self.pop(1) + self.emit('ROT_TWO') + self.emit('POP_TOP') l2.bind(self.code.getCurInst()) return 1 def visitGetattr(self, node): self.visit(node.expr) - self.code.emit('LOAD_ATTR', node.attrname) - self.push(1) + self.emit('LOAD_ATTR', node.attrname) return 1 def visitSubscript(self, node): self.visit(node.expr) for sub in node.subs[:-1]: self.visit(sub) - self.code.emit('BINARY_SUBSCR') + self.emit('BINARY_SUBSCR') self.visit(node.subs[-1]) if node.flags == 'OP_APPLY': - self.code.emit('BINARY_SUBSCR') - else: - self.code.emit('STORE_SUBSCR') + self.emit('BINARY_SUBSCR') + elif node.flags == 'OP_ASSIGN': + self.emit('STORE_SUBSCR') + elif node.flags == 'OP_DELETE': + self.emit('DELETE_SUBSCR') return 1 @@ -517,26 +509,29 @@ class CodeGenerator: if node.lower: self.visit(node.lower) slice = slice | 1 - self.pop(1) if node.upper: self.visit(node.upper) slice = slice | 2 - self.pop(1) if node.flags == 'OP_APPLY': - self.code.emit('SLICE+%d' % slice) + self.emit('SLICE+%d' % slice) elif node.flags == 'OP_ASSIGN': - self.code.emit('STORE_SLICE+%d' % slice) + self.emit('STORE_SLICE+%d' % slice) elif node.flags == 'OP_DELETE': - self.code.emit('DELETE_SLICE+%d' % slice) + self.emit('DELETE_SLICE+%d' % slice) else: print node.flags raise return 1 def visitAssign(self, node): - self.code.setLineNo(node.lineno) + print "ASSIGN", node.expr + self.emit('SET_LINENO', node.lineno) self.visit(node.expr) - for elt in node.nodes: + dups = len(node.nodes) - 1 + for i in range(len(node.nodes)): + elt = node.nodes[i] + if i < dups: + self.emit('DUP_TOP') if isinstance(elt, ast.Node): self.visit(elt) return 1 @@ -545,18 +540,17 @@ class CodeGenerator: if node.flags != 'OP_ASSIGN': print "oops", node.flags self.storeName(node.name) - self.pop(1) def visitAssAttr(self, node): if node.flags != 'OP_ASSIGN': print "warning: unexpected flags:", node.flags print node self.visit(node.expr) - self.code.emit('STORE_ATTR', node.attrname) + self.emit('STORE_ATTR', node.attrname) return 1 def visitAssTuple(self, node): - self.code.emit('UNPACK_TUPLE', len(node.nodes)) + self.emit('UNPACK_TUPLE', len(node.nodes)) for child in node.nodes: self.visit(child) return 1 @@ -566,13 +560,12 @@ class CodeGenerator: def binaryOp(self, node, op): self.visit(node.left) self.visit(node.right) - self.code.emit(op) - self.pop(1) + self.emit(op) return 1 def unaryOp(self, node, op): self.visit(node.expr) - self.code.emit(op) + self.emit(op) return 1 def visitAdd(self, node): @@ -605,16 +598,50 @@ class CodeGenerator: def visitBackquote(self, node): return self.unaryOp(node, 'UNARY_CONVERT') + def bitOp(self, nodes, op): + self.visit(nodes[0]) + for node in nodes[1:]: + self.visit(node) + self.emit(op) + return 1 + + def visitBitand(self, node): + return self.bitOp(node.nodes, 'BINARY_AND') + + def visitBitor(self, node): + return self.bitOp(node.nodes, 'BINARY_OR') + + def visitBitxor(self, node): + return self.bitOp(node.nodes, 'BINARY_XOR') + def visitTest(self, node, jump): end = StackRef() for child in node.nodes[:-1]: self.visit(child) - self.code.emit(jump, end) - self.code.emit('POP_TOP') + self.emit(jump, end) + self.emit('POP_TOP') self.visit(node.nodes[-1]) end.bind(self.code.getCurInst()) return 1 + def visitAssert(self, node): + # XXX __debug__ and AssertionError appear to be special cases + # -- they are always loaded as globals even if there are local + # names. I guess this is a sort of renaming op. + skip = StackRef() + self.emit('SET_LINENO', node.lineno) + self.emit('LOAD_GLOBAL', '__debug__') + self.emit('JUMP_IF_FALSE', skip) + self.emit('POP_TOP') + self.visit(node.test) + self.emit('JUMP_IF_TRUE', skip) + self.emit('LOAD_GLOBAL', 'AssertionError') + self.visit(node.fail) + self.emit('RAISE_VARARGS', 2) + skip.bind(self.code.getCurInst()) + self.emit('POP_TOP') + return 1 + def visitAnd(self, node): return self.visitTest(node, 'JUMP_IF_FALSE') @@ -623,37 +650,46 @@ class CodeGenerator: def visitName(self, node): self.loadName(node.name) - self.push(1) def visitConst(self, node): - self.code.loadConst(node.value) - self.push(1) + self.emit('LOAD_CONST', node.value) return 1 + def visitEllipsis(self, node): + self.emit('LOAD_CONST', Ellipsis) + return 1 + def visitTuple(self, node): for elt in node.nodes: self.visit(elt) - self.code.emit('BUILD_TUPLE', len(node.nodes)) - self.pop(len(node.nodes)) + self.emit('BUILD_TUPLE', len(node.nodes)) return 1 def visitList(self, node): for elt in node.nodes: self.visit(elt) - self.code.emit('BUILD_LIST', len(node.nodes)) - self.pop(len(node.nodes)) + self.emit('BUILD_LIST', len(node.nodes)) return 1 + def visitDict(self, node): + self.emit('BUILD_MAP', 0) + for k, v in node.items: + # XXX need to add set lineno when there aren't constants + self.emit('DUP_TOP') + self.visit(v) + self.emit('ROT_TWO') + self.visit(k) + self.emit('STORE_SUBSCR') + return 1 + def visitReturn(self, node): - self.code.setLineNo(node.lineno) + self.emit('SET_LINENO', node.lineno) self.visit(node.value) - self.code.returnValue() - self.pop(1) - self.assertStackEmpty() + self.emit('RETURN_VALUE') return 1 def visitRaise(self, node): - self.code.setLineNo(node.lineno) + self.emit('SET_LINENO', node.lineno) n = 0 if node.expr1: self.visit(node.expr1) @@ -664,22 +700,33 @@ class CodeGenerator: if node.expr3: self.visit(node.expr3) n = n + 1 - self.code.raiseVarargs(n) + self.emit('RAISE_VARARGS', n) return 1 def visitPrint(self, node): - self.code.setLineNo(node.lineno) + self.emit('SET_LINENO', node.lineno) for child in node.nodes: self.visit(child) - self.code.emit('PRINT_ITEM') - self.pop(len(node.nodes)) + self.emit('PRINT_ITEM') return 1 def visitPrintnl(self, node): self.visitPrint(node) - self.code.emit('PRINT_NEWLINE') + self.emit('PRINT_NEWLINE') return 1 + def visitExec(self, node): + self.visit(node.expr) + if node.locals is None: + self.emit('LOAD_CONST', None) + else: + self.visit(node.locals) + if node.globals is None: + self.emit('DUP_TOP') + else: + self.visit(node.globals) + self.emit('EXEC_STMT') + class LocalNameFinder: def __init__(self, names=()): self.names = misc.Set() @@ -693,6 +740,9 @@ class LocalNameFinder: self.names.remove(elt) return self.names + def visitDict(self, node): + return 1 + def visitGlobal(self, node): for name in node.names: self.globals.add(name) @@ -726,406 +776,6 @@ class Loop: self.breakAnchor = StackRef() self.extentAnchor = StackRef() -class StackRef: - """Manage stack locations for jumps, loops, etc.""" - count = 0 - - def __init__(self, id=None, val=None): - if id is None: - id = StackRef.count - StackRef.count = StackRef.count + 1 - self.id = id - self.val = val - - def __repr__(self): - if self.val: - return "StackRef(val=%d)" % self.val - else: - return "StackRef(id=%d)" % self.id - - def bind(self, inst): - self.val = inst - - def resolve(self): - if self.val is None: - print "UNRESOLVE REF", self - return 0 - return self.val - -def add_hook(hooks, type, meth): - """Helper function for PythonVMCode _emit_hooks""" - l = hooks.get(type, []) - l.append(meth) - hooks[type] = l - -class PythonVMCode: - """Creates Python code objects - - The new module is used to create the code object. The following - attribute definitions are included from the reference manual: - - co_name gives the function name - co_argcount is the number of positional arguments (including - arguments with default values) - co_nlocals is the number of local variables used by the function - (including arguments) - co_varnames is a tuple containing the names of the local variables - (starting with the argument names) - co_code is a string representing the sequence of bytecode instructions - co_consts is a tuple containing the literals used by the bytecode - co_names is a tuple containing the names used by the bytecode - co_filename is the filename from which the code was compiled - co_firstlineno is the first line number of the function - co_lnotab is a string encoding the mapping from byte code offsets - to line numbers (for detais see the source code of the - interpreter) - see code com_set_lineno and com_add_lnotab - it's a string with 2bytes per set_lineno - - co_stacksize is the required stack size (including local variables) - co_flags is an integer encoding a number of flags for the - interpreter. - - The following flag bits are defined for co_flags: bit 2 is set if - the function uses the "*arguments" syntax to accept an arbitrary - number of positional arguments; bit 3 is set if the function uses - the "**keywords" syntax to accept arbitrary keyword arguments; - other bits are used internally or reserved for future use. - - If a code object represents a function, the first item in - co_consts is the documentation string of the function, or None if - undefined. - """ - - # XXX flag bits - CO_OPTIMIZED = 0x0001 # uses LOAD_FAST! - CO_NEWLOCALS = 0x0002 # everybody uses this? - CO_VARARGS = 0x0004 - CO_VARKEYWORDS = 0x0008 - - def __init__(self, args=(), name='?', filename='<?>', - docstring=None): - # XXX why is the default value for flags 3? - self.insts = [] - # used by makeCodeObject - self.argcount = len(args) - self.code = '' - self.consts = [docstring] - self.filename = filename - self.flags = self.CO_NEWLOCALS - self.name = name - self.names = [] - self.varnames = list(args) or [] - # lnotab support - self.firstlineno = 0 - self.lastlineno = 0 - self.last_addr = 0 - self.lnotab = '' - - def __repr__(self): - return "<bytecode: %d instrs>" % len(self.insts) - - def setFlags(self, val): - """XXX for module's function""" - self.flags = val - - def setOptimized(self): - self.flags = self.flags | self.CO_OPTIMIZED - - def setVarArgs(self): - self.flags = self.flags | self.CO_VARARGS - - def setKWArgs(self): - self.flags = self.flags | self.CO_VARKEYWORDS - - def getCurInst(self): - return len(self.insts) - - def getNextInst(self): - return len(self.insts) + 1 - - def dump(self, io=sys.stdout): - i = 0 - for inst in self.insts: - if inst[0] == 'SET_LINENO': - io.write("\n") - io.write(" %3d " % i) - if len(inst) == 1: - io.write("%s\n" % inst) - else: - io.write("%-15.15s\t%s\n" % inst) - i = i + 1 - - def makeCodeObject(self, stacksize): - """Make a Python code object - - This creates a Python code object using the new module. This - seems simpler than reverse-engineering the way marshal dumps - code objects into .pyc files. One of the key difficulties is - figuring out how to layout references to code objects that - appear on the VM stack; e.g. - 3 SET_LINENO 1 - 6 LOAD_CONST 0 (<code object fact at 8115878 [...] - 9 MAKE_FUNCTION 0 - 12 STORE_NAME 0 (fact) - """ - - self._findOffsets() - lnotab = LineAddrTable() - for t in self.insts: - opname = t[0] - if len(t) == 1: - lnotab.addCode(chr(self.opnum[opname])) - elif len(t) == 2: - oparg = self._convertArg(opname, t[1]) - if opname == 'SET_LINENO': - lnotab.nextLine(oparg) - try: - hi, lo = divmod(oparg, 256) - except TypeError: - raise TypeError, "untranslated arg: %s, %s" % (opname, oparg) - lnotab.addCode(chr(self.opnum[opname]) + chr(lo) + - chr(hi)) - # why is a module a special case? - if self.flags == 0: - nlocals = 0 - else: - nlocals = len(self.varnames) - # XXX danger! can't pass through here twice - if self.flags & self.CO_VARKEYWORDS: - self.argcount = self.argcount - 1 - co = new.code(self.argcount, nlocals, stacksize, - self.flags, lnotab.getCode(), self._getConsts(), - tuple(self.names), tuple(self.varnames), - self.filename, self.name, self.firstlineno, - lnotab.getTable()) - return co - - def _getConsts(self): - """Return a tuple for the const slot of a code object - - Converts PythonVMCode objects to code objects - """ - l = [] - for elt in self.consts: - if isinstance(elt, CodeGenerator): - l.append(elt.emit()) - else: - l.append(elt) - return tuple(l) - - def _findOffsets(self): - """Find offsets for use in resolving StackRefs""" - self.offsets = [] - cur = 0 - for t in self.insts: - self.offsets.append(cur) - l = len(t) - if l == 1: - cur = cur + 1 - elif l == 2: - cur = cur + 3 - arg = t[1] - # XXX this is a total hack: for a reference used - # multiple times, we create a list of offsets and - # expect that we when we pass through the code again - # to actually generate the offsets, we'll pass in the - # same order. - if isinstance(arg, StackRef): - try: - arg.__offset.append(cur) - except AttributeError: - arg.__offset = [cur] - - def _convertArg(self, op, arg): - """Convert the string representation of an arg to a number - - The specific handling depends on the opcode. - - XXX This first implementation isn't going to be very - efficient. - """ - if op == 'SET_LINENO': - return arg - if op == 'LOAD_CONST': - return self._lookupName(arg, self.consts) - if op in self.localOps: - # make sure it's in self.names, but use the bytecode offset - self._lookupName(arg, self.names) - return self._lookupName(arg, self.varnames) - if op in self.globalOps: - return self._lookupName(arg, self.names) - if op in self.nameOps: - return self._lookupName(arg, self.names) - if op == 'COMPARE_OP': - return self.cmp_op.index(arg) - if self.hasjrel.has_elt(op): - offset = arg.__offset[0] - del arg.__offset[0] - return self.offsets[arg.resolve()] - offset - if self.hasjabs.has_elt(op): - return self.offsets[arg.resolve()] - return arg - - nameOps = ('STORE_NAME', 'IMPORT_NAME', 'IMPORT_FROM', - 'STORE_ATTR', 'LOAD_ATTR', 'LOAD_NAME', 'DELETE_NAME') - localOps = ('LOAD_FAST', 'STORE_FAST', 'DELETE_FAST') - globalOps = ('LOAD_GLOBAL', 'STORE_GLOBAL', 'DELETE_GLOBAL') - - def _lookupName(self, name, list, list2=None): - """Return index of name in list, appending if necessary - - Yicky hack: Second list can be used for lookup of local names - where the name needs to be added to varnames and names. - """ - if name in list: - return list.index(name) - else: - end = len(list) - list.append(name) - if list2 is not None: - list2.append(name) - return end - - # Convert some stuff from the dis module for local use - - cmp_op = list(dis.cmp_op) - hasjrel = misc.Set() - for i in dis.hasjrel: - hasjrel.add(dis.opname[i]) - hasjabs = misc.Set() - for i in dis.hasjabs: - hasjabs.add(dis.opname[i]) - - opnum = {} - for num in range(len(dis.opname)): - opnum[dis.opname[num]] = num - - # the interface below here seemed good at first. upon real use, - # it seems redundant to add a function for each opcode, - # particularly because the method and opcode basically have the - # same name. - # on the other hand, we need to track things like stack depth in - # order to generator code objects. if we wrap instructions in a - # method, we get an easy way to track these. a simpler - # approach, however, would be to define hooks that can be called - # by emit. - - def setLineNo(self, num): - self.emit('SET_LINENO', num) - - def popTop(self): - self.emit('POP_TOP') - - def dupTop(self): - self.emit('DUP_TOP') - - def rotTwo(self): - self.emit('ROT_TWO') - - def rotThree(self): - self.emit('ROT_THREE') - - def jumpIfFalse(self, dest): - self.emit('JUMP_IF_FALSE', dest) - - def loadFast(self, name): - self.emit('LOAD_FAST', name) - - def loadGlobal(self, name): - self.emit('LOAD_GLOBAL', name) - - def binaryAdd(self): - self.emit('BINARY_ADD') - - def compareOp(self, op): - self.emit('COMPARE_OP', op) - - def loadConst(self, val): - self.emit('LOAD_CONST', val) - - def returnValue(self): - self.emit('RETURN_VALUE') - - def jumpForward(self, dest): - self.emit('JUMP_FORWARD', dest) - - def raiseVarargs(self, num): - self.emit('RAISE_VARARGS', num) - - def callFunction(self, num): - self.emit('CALL_FUNCTION', num) - - # this version of emit + arbitrary hooks might work, but it's damn - # messy. - - def emit(self, *args): - self._emitDispatch(args[0], args[1:]) - self.insts.append(args) - - def _emitDispatch(self, type, args): - for func in self._emit_hooks.get(type, []): - func(self, args) - - _emit_hooks = {} - -class LineAddrTable: - """lnotab - - This class builds the lnotab, which is undocumented but described - by com_set_lineno in compile.c. Here's an attempt at explanation: - - For each SET_LINENO instruction after the first one, two bytes are - added to lnotab. (In some cases, multiple two-byte entries are - added.) The first byte is the distance in bytes between the - instruction for the last SET_LINENO and the current SET_LINENO. - The second byte is offset in line numbers. If either offset is - greater than 255, multiple two-byte entries are added -- one entry - for each factor of 255. - """ - - def __init__(self): - self.code = [] - self.codeOffset = 0 - self.firstline = 0 - self.lastline = 0 - self.lastoff = 0 - self.lnotab = [] - - def addCode(self, code): - self.code.append(code) - self.codeOffset = self.codeOffset + len(code) - - def nextLine(self, lineno): - if self.firstline == 0: - self.firstline = lineno - self.lastline = lineno - else: - # compute deltas - addr = self.codeOffset - self.lastoff - line = lineno - self.lastline - while addr > 0 or line > 0: - # write the values in 1-byte chunks that sum - # to desired value - trunc_addr = addr - trunc_line = line - if trunc_addr > 255: - trunc_addr = 255 - if trunc_line > 255: - trunc_line = 255 - self.lnotab.append(trunc_addr) - self.lnotab.append(trunc_line) - addr = addr - trunc_addr - line = line - trunc_line - self.lastline = lineno - self.lastoff = self.codeOffset - - def getCode(self): - return string.join(self.code, '') - - def getTable(self): - return string.join(map(chr, self.lnotab), '') - class CompiledModule: """Store the code object for a compiled module @@ -1145,7 +795,7 @@ class CompiledModule: self.ast = t.parsesuite(self.source) cg = CodeGenerator(self.filename) walk(self.ast, cg, walker=ExampleASTVisitor) - self.code = cg.emit() + self.code = cg.asConst() def dump(self, path): """create a .pyc file""" |