Mercurial > hg
view mercurial/templater.py @ 20066:64b4f0cd7336 stable
templater: fix escaping in nested string literals (issue4102)
Before the templater got extended for nested expressions, it made
sense to decode string escapes across the whole string. Now we do it
on a piece by piece basis.
author | Matt Mackall <mpm@selenic.com> |
---|---|
date | Mon, 18 Nov 2013 14:02:26 -0500 |
parents | 0361163efbaf |
children | 3d8bfe2ecf6d |
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# templater.py - template expansion for output # # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from i18n import _ import sys, os, re import util, config, templatefilters, parser, error import types import minirst # template parsing elements = { "(": (20, ("group", 1, ")"), ("func", 1, ")")), ",": (2, None, ("list", 2)), "|": (5, None, ("|", 5)), "%": (6, None, ("%", 6)), ")": (0, None, None), "symbol": (0, ("symbol",), None), "string": (0, ("string",), None), "end": (0, None, None), } def tokenizer(data): program, start, end = data pos = start while pos < end: c = program[pos] if c.isspace(): # skip inter-token whitespace pass elif c in "(,)%|": # handle simple operators yield (c, None, pos) elif (c in '"\'' or c == 'r' and program[pos:pos + 2] in ("r'", 'r"')): # handle quoted strings if c == 'r': pos += 1 c = program[pos] decode = False else: decode = True pos += 1 s = pos while pos < end: # find closing quote d = program[pos] if decode and d == '\\': # skip over escaped characters pos += 2 continue if d == c: if not decode: yield ('string', program[s:pos].replace('\\', r'\\'), s) break yield ('string', program[s:pos], s) break pos += 1 else: raise error.ParseError(_("unterminated string"), s) elif c.isalnum() or c in '_': s = pos pos += 1 while pos < end: # find end of symbol d = program[pos] if not (d.isalnum() or d == "_"): break pos += 1 sym = program[s:pos] yield ('symbol', sym, s) pos -= 1 elif c == '}': pos += 1 break else: raise error.ParseError(_("syntax error"), pos) pos += 1 yield ('end', None, pos) def compiletemplate(tmpl, context): parsed = [] pos, stop = 0, len(tmpl) p = parser.parser(tokenizer, elements) while pos < stop: n = tmpl.find('{', pos) if n < 0: parsed.append(("string", tmpl[pos:].decode("string-escape"))) break if n > 0 and tmpl[n - 1] == '\\': # escaped parsed.append(("string", (tmpl[pos:n - 1] + "{").decode("string-escape"))) pos = n + 1 continue if n > pos: parsed.append(("string", tmpl[pos:n].decode("string-escape"))) pd = [tmpl, n + 1, stop] parseres, pos = p.parse(pd) parsed.append(parseres) return [compileexp(e, context) for e in parsed] def compileexp(exp, context): t = exp[0] if t in methods: return methods[t](exp, context) raise error.ParseError(_("unknown method '%s'") % t) # template evaluation def getsymbol(exp): if exp[0] == 'symbol': return exp[1] raise error.ParseError(_("expected a symbol")) def getlist(x): if not x: return [] if x[0] == 'list': return getlist(x[1]) + [x[2]] return [x] def getfilter(exp, context): f = getsymbol(exp) if f not in context._filters: raise error.ParseError(_("unknown function '%s'") % f) return context._filters[f] def gettemplate(exp, context): if exp[0] == 'string': return compiletemplate(exp[1], context) if exp[0] == 'symbol': return context._load(exp[1]) raise error.ParseError(_("expected template specifier")) def runstring(context, mapping, data): return data def runsymbol(context, mapping, key): v = mapping.get(key) if v is None: v = context._defaults.get(key) if v is None: try: v = context.process(key, mapping) except TemplateNotFound: v = '' if util.safehasattr(v, '__call__'): return v(**mapping) if isinstance(v, types.GeneratorType): v = list(v) mapping[key] = v return v return v def buildfilter(exp, context): func, data = compileexp(exp[1], context) filt = getfilter(exp[2], context) return (runfilter, (func, data, filt)) def runfilter(context, mapping, data): func, data, filt = data try: return filt(func(context, mapping, data)) except (ValueError, AttributeError, TypeError): if isinstance(data, tuple): dt = data[1] else: dt = data raise util.Abort(_("template filter '%s' is not compatible with " "keyword '%s'") % (filt.func_name, dt)) def buildmap(exp, context): func, data = compileexp(exp[1], context) ctmpl = gettemplate(exp[2], context) return (runmap, (func, data, ctmpl)) def runtemplate(context, mapping, template): for func, data in template: yield func(context, mapping, data) def runmap(context, mapping, data): func, data, ctmpl = data d = func(context, mapping, data) if util.safehasattr(d, '__call__'): d = d() lm = mapping.copy() for i in d: if isinstance(i, dict): lm.update(i) lm['originalnode'] = mapping.get('node') yield runtemplate(context, lm, ctmpl) else: # v is not an iterable of dicts, this happen when 'key' # has been fully expanded already and format is useless. # If so, return the expanded value. yield i def buildfunc(exp, context): n = getsymbol(exp[1]) args = [compileexp(x, context) for x in getlist(exp[2])] if n in funcs: f = funcs[n] return (f, args) if n in context._filters: if len(args) != 1: raise error.ParseError(_("filter %s expects one argument") % n) f = context._filters[n] return (runfilter, (args[0][0], args[0][1], f)) def date(context, mapping, args): if not (1 <= len(args) <= 2): raise error.ParseError(_("date expects one or two arguments")) date = args[0][0](context, mapping, args[0][1]) if len(args) == 2: fmt = stringify(args[1][0](context, mapping, args[1][1])) return util.datestr(date, fmt) return util.datestr(date) def fill(context, mapping, args): if not (1 <= len(args) <= 4): raise error.ParseError(_("fill expects one to four arguments")) text = stringify(args[0][0](context, mapping, args[0][1])) width = 76 initindent = '' hangindent = '' if 2 <= len(args) <= 4: try: width = int(stringify(args[1][0](context, mapping, args[1][1]))) except ValueError: raise error.ParseError(_("fill expects an integer width")) try: initindent = stringify(args[2][0](context, mapping, args[2][1])) initindent = stringify(runtemplate(context, mapping, compiletemplate(initindent, context))) hangindent = stringify(args[3][0](context, mapping, args[3][1])) hangindent = stringify(runtemplate(context, mapping, compiletemplate(hangindent, context))) except IndexError: pass return templatefilters.fill(text, width, initindent, hangindent) def get(context, mapping, args): if len(args) != 2: # i18n: "get" is a keyword raise error.ParseError(_("get() expects two arguments")) dictarg = args[0][0](context, mapping, args[0][1]) if not util.safehasattr(dictarg, 'get'): # i18n: "get" is a keyword raise error.ParseError(_("get() expects a dict as first argument")) key = args[1][0](context, mapping, args[1][1]) yield dictarg.get(key) def if_(context, mapping, args): if not (2 <= len(args) <= 3): # i18n: "if" is a keyword raise error.ParseError(_("if expects two or three arguments")) test = stringify(args[0][0](context, mapping, args[0][1])) if test: t = stringify(args[1][0](context, mapping, args[1][1])) yield runtemplate(context, mapping, compiletemplate(t, context)) elif len(args) == 3: t = stringify(args[2][0](context, mapping, args[2][1])) yield runtemplate(context, mapping, compiletemplate(t, context)) def ifeq(context, mapping, args): if not (3 <= len(args) <= 4): # i18n: "ifeq" is a keyword raise error.ParseError(_("ifeq expects three or four arguments")) test = stringify(args[0][0](context, mapping, args[0][1])) match = stringify(args[1][0](context, mapping, args[1][1])) if test == match: t = stringify(args[2][0](context, mapping, args[2][1])) yield runtemplate(context, mapping, compiletemplate(t, context)) elif len(args) == 4: t = stringify(args[3][0](context, mapping, args[3][1])) yield runtemplate(context, mapping, compiletemplate(t, context)) def join(context, mapping, args): if not (1 <= len(args) <= 2): # i18n: "join" is a keyword raise error.ParseError(_("join expects one or two arguments")) joinset = args[0][0](context, mapping, args[0][1]) if util.safehasattr(joinset, '__call__'): jf = joinset.joinfmt joinset = [jf(x) for x in joinset()] joiner = " " if len(args) > 1: joiner = args[1][0](context, mapping, args[1][1]) first = True for x in joinset: if first: first = False else: yield joiner yield x def label(context, mapping, args): if len(args) != 2: # i18n: "label" is a keyword raise error.ParseError(_("label expects two arguments")) # ignore args[0] (the label string) since this is supposed to be a a no-op t = stringify(args[1][0](context, mapping, args[1][1])) yield runtemplate(context, mapping, compiletemplate(t, context)) def rstdoc(context, mapping, args): if len(args) != 2: # i18n: "rstdoc" is a keyword raise error.ParseError(_("rstdoc expects two arguments")) text = stringify(args[0][0](context, mapping, args[0][1])) style = stringify(args[1][0](context, mapping, args[1][1])) return minirst.format(text, style=style, keep=['verbose']) def strip(context, mapping, args): if not (1 <= len(args) <= 2): raise error.ParseError(_("strip expects one or two arguments")) text = args[0][0](context, mapping, args[0][1]) if len(args) == 2: chars = args[1][0](context, mapping, args[1][1]) return text.strip(chars) return text.strip() def sub(context, mapping, args): if len(args) != 3: # i18n: "sub" is a keyword raise error.ParseError(_("sub expects three arguments")) pat = stringify(args[0][0](context, mapping, args[0][1])) rpl = stringify(args[1][0](context, mapping, args[1][1])) src = stringify(args[2][0](context, mapping, args[2][1])) src = stringify(runtemplate(context, mapping, compiletemplate(src, context))) yield re.sub(pat, rpl, src) methods = { "string": lambda e, c: (runstring, e[1]), "symbol": lambda e, c: (runsymbol, e[1]), "group": lambda e, c: compileexp(e[1], c), # ".": buildmember, "|": buildfilter, "%": buildmap, "func": buildfunc, } funcs = { "date": date, "fill": fill, "get": get, "if": if_, "ifeq": ifeq, "join": join, "label": label, "rstdoc": rstdoc, "strip": strip, "sub": sub, } # template engine path = ['templates', '../templates'] stringify = templatefilters.stringify def _flatten(thing): '''yield a single stream from a possibly nested set of iterators''' if isinstance(thing, str): yield thing elif not util.safehasattr(thing, '__iter__'): if thing is not None: yield str(thing) else: for i in thing: if isinstance(i, str): yield i elif not util.safehasattr(i, '__iter__'): if i is not None: yield str(i) elif i is not None: for j in _flatten(i): yield j def parsestring(s, quoted=True): '''parse a string using simple c-like syntax. string must be in quotes if quoted is True.''' if quoted: if len(s) < 2 or s[0] != s[-1]: raise SyntaxError(_('unmatched quotes')) return s[1:-1].decode('string_escape') return s.decode('string_escape') class engine(object): '''template expansion engine. template expansion works like this. a map file contains key=value pairs. if value is quoted, it is treated as string. otherwise, it is treated as name of template file. templater is asked to expand a key in map. it looks up key, and looks for strings like this: {foo}. it expands {foo} by looking up foo in map, and substituting it. expansion is recursive: it stops when there is no more {foo} to replace. expansion also allows formatting and filtering. format uses key to expand each item in list. syntax is {key%format}. filter uses function to transform value. syntax is {key|filter1|filter2|...}.''' def __init__(self, loader, filters={}, defaults={}): self._loader = loader self._filters = filters self._defaults = defaults self._cache = {} def _load(self, t): '''load, parse, and cache a template''' if t not in self._cache: self._cache[t] = compiletemplate(self._loader(t), self) return self._cache[t] def process(self, t, mapping): '''Perform expansion. t is name of map element to expand. mapping contains added elements for use during expansion. Is a generator.''' return _flatten(runtemplate(self, mapping, self._load(t))) engines = {'default': engine} def stylelist(): path = templatepath()[0] dirlist = os.listdir(path) stylelist = [] for file in dirlist: split = file.split(".") if split[0] == "map-cmdline": stylelist.append(split[1]) return ", ".join(sorted(stylelist)) class TemplateNotFound(util.Abort): pass class templater(object): def __init__(self, mapfile, filters={}, defaults={}, cache={}, minchunk=1024, maxchunk=65536): '''set up template engine. mapfile is name of file to read map definitions from. filters is dict of functions. each transforms a value into another. defaults is dict of default map definitions.''' self.mapfile = mapfile or 'template' self.cache = cache.copy() self.map = {} self.base = (mapfile and os.path.dirname(mapfile)) or '' self.filters = templatefilters.filters.copy() self.filters.update(filters) self.defaults = defaults self.minchunk, self.maxchunk = minchunk, maxchunk self.ecache = {} if not mapfile: return if not os.path.exists(mapfile): raise util.Abort(_("style '%s' not found") % mapfile, hint=_("available styles: %s") % stylelist()) conf = config.config() conf.read(mapfile) for key, val in conf[''].items(): if not val: raise SyntaxError(_('%s: missing value') % conf.source('', key)) if val[0] in "'\"": try: self.cache[key] = parsestring(val) except SyntaxError, inst: raise SyntaxError('%s: %s' % (conf.source('', key), inst.args[0])) else: val = 'default', val if ':' in val[1]: val = val[1].split(':', 1) self.map[key] = val[0], os.path.join(self.base, val[1]) def __contains__(self, key): return key in self.cache or key in self.map def load(self, t): '''Get the template for the given template name. Use a local cache.''' if t not in self.cache: try: self.cache[t] = util.readfile(self.map[t][1]) except KeyError, inst: raise TemplateNotFound(_('"%s" not in template map') % inst.args[0]) except IOError, inst: raise IOError(inst.args[0], _('template file %s: %s') % (self.map[t][1], inst.args[1])) return self.cache[t] def __call__(self, t, **mapping): ttype = t in self.map and self.map[t][0] or 'default' if ttype not in self.ecache: self.ecache[ttype] = engines[ttype](self.load, self.filters, self.defaults) proc = self.ecache[ttype] stream = proc.process(t, mapping) if self.minchunk: stream = util.increasingchunks(stream, min=self.minchunk, max=self.maxchunk) return stream def templatepath(name=None): '''return location of template file or directory (if no name). returns None if not found.''' normpaths = [] # executable version (py2exe) doesn't support __file__ if util.mainfrozen(): module = sys.executable else: module = __file__ for f in path: if f.startswith('/'): p = f else: fl = f.split('/') p = os.path.join(os.path.dirname(module), *fl) if name: p = os.path.join(p, name) if name and os.path.exists(p): return os.path.normpath(p) elif os.path.isdir(p): normpaths.append(os.path.normpath(p)) return normpaths def stylemap(styles, paths=None): """Return path to mapfile for a given style. Searches mapfile in the following locations: 1. templatepath/style/map 2. templatepath/map-style 3. templatepath/map """ if paths is None: paths = templatepath() elif isinstance(paths, str): paths = [paths] if isinstance(styles, str): styles = [styles] for style in styles: if not style: continue locations = [os.path.join(style, 'map'), 'map-' + style] locations.append('map') for path in paths: for location in locations: mapfile = os.path.join(path, location) if os.path.isfile(mapfile): return style, mapfile raise RuntimeError("No hgweb templates found in %r" % paths)