# Copyright 2015 Canonical Ltd. # # This program is free software: you can redistribute it and/or modify it # under the terms of the GNU General Public License version 3, as published # by the Free Software Foundation. # # This program is distributed in the hope that it will be useful, but # WITHOUT ANY WARRANTY; without even the implied warranties of # MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR # PURPOSE. See the GNU General Public License for more details. # # You should have received a copy of the GNU General Public License along # with this program. If not, see . """Handle recipe parsing and substitution variables.""" import datetime from functools import lru_cache import logging import os import subprocess import sys from urllib.parse import urlparse import dateutil.parser from debian import debian_support MERGE_INSTRUCTION = "merge" NEST_PART_INSTRUCTION = "nest-part" NEST_INSTRUCTION = "nest" RUN_INSTRUCTION = "run" USAGE = { MERGE_INSTRUCTION: 'merge NAME BRANCH [REVISION]', NEST_INSTRUCTION: 'nest NAME BRANCH TARGET-DIR [REVISION]', NEST_PART_INSTRUCTION: 'nest-part NAME BRANCH SUBDIR [TARGET-DIR [REVISION]]', RUN_INSTRUCTION: 'run COMMAND', } SAFE_INSTRUCTIONS = [ MERGE_INSTRUCTION, NEST_PART_INSTRUCTION, NEST_INSTRUCTION] class FormattedError(Exception): def __init__(self, **kwargs): super().__init__() for key, value in kwargs.items(): setattr(self, key, value) def __str__(self): return self._fmt % dict(self.__dict__) def __repr__(self): return "%s(%s)" % (self.__class__.__name__, str(self)) def __eq__(self, other): if self.__class__ is not other.__class__: return NotImplemented return self.__dict__ == other.__dict__ def __ne__(self, other): if self.__class__ is not other.__class__: return NotImplemented return self.__dict__ != other.__dict__ __hash__ = Exception.__hash__ class SubstitutionUnavailable(FormattedError): _fmt = "Substitution for %(name)s not available: %(reason)s" def __init__(self, name, reason): super().__init__(name=name, reason=reason) class SubstitutionVariable: """A substitution variable for a version string.""" def replace(self, value): """Replace name with value.""" raise NotImplementedError(self.replace) @classmethod def available_in(cls, format): """Check if this variable is available in a particular format.""" raise NotImplementedError(cls.available_in) class SimpleSubstitutionVariable(SubstitutionVariable): name = None minimum_format = None def replace(self, value): if not self.name in value: return value return value.replace(self.name, self.get()) def get(self): raise NotImplementedError(self.value) @classmethod def available_in(self, format): return format >= self.minimum_format class BranchSubstitutionVariable(SimpleSubstitutionVariable): basename = None def __init__(self, branch_name=None): super().__init__() self.branch_name = branch_name @classmethod def determine_name(cls, branch_name): if branch_name is None: return "{%s}" % cls.basename else: return "{%s:%s}" % (cls.basename, branch_name) @property def name(self): return self.determine_name(self.branch_name) class TimeVariable(SimpleSubstitutionVariable): name = "{time}" minimum_format = 0.1 def __init__(self, time): self._time = time def get(self): return self._time.strftime("%Y%m%d%H%M") class DateVariable(SimpleSubstitutionVariable): name = "{date}" minimum_format = 0.1 def __init__(self, time): self._time = time def get(self): return self._time.strftime("%Y%m%d") class RevisionVariable(BranchSubstitutionVariable): minimum_format = 0.1 def __init__(self, branch): super().__init__(branch.name) self.branch = branch self.commit = branch.commit class RevnoVariable(RevisionVariable): """A {revno} substitution variable. This is a distinctly un-git-like bzr-ism, and is therefore a hack. Most users should use {revtime} or {revdate} instead, which is monotonically increasing, or perhaps also {git-commit} to ensure uniqueness (but note that commit hashes do not increase monotonically, so are not normally suitable in version strings). However, this can result in very long version strings, especially if there are multiple branches involved; so this may for instance be useful as {revno:packaging} to encode the length of the packaging branch. This produces an approximation of a bzr revno by taking the length of the left-hand history. """ basename = "revno" minimum_format = 0.1 def get(self): return self.branch.git_output( "rev-list", "--first-parent", "--count", self.commit).rstrip("\n") class RevtimeVariable(RevisionVariable): basename = "revtime" minimum_format = 0.4 def get(self): dt = dateutil.parser.parse(self.branch.git_output( "log", "-1", "--date=iso", "--format=format:%cd", self.commit)) return dt.astimezone(datetime.timezone.utc).strftime("%Y%m%d%H%M") class RevdateVariable(RevisionVariable): basename = "revdate" minimum_format = 0.4 def get(self): dt = dateutil.parser.parse(self.branch.git_output( "log", "-1", "--date=iso", "--format=format:%cd", self.commit)) return dt.astimezone(datetime.timezone.utc).strftime("%Y%m%d") class GitCommitVariable(RevisionVariable): basename = "git-commit" minimum_format = 0.4 def get(self): return self.branch.git_output( "rev-parse", "--short", self.commit).rstrip("\n") class LatestTagVariable(RevisionVariable): basename = "latest-tag" minimum_format = 0.4 def get(self): # Capture stderr so that exceptions are useful. We know that git # describe does not write to stderr on success. return self.branch.git_output( "describe", "--tags", "--abbrev=0", self.commit, stderr=subprocess.STDOUT).rstrip("\n") branch_vars = [ GitCommitVariable, LatestTagVariable, RevdateVariable, RevtimeVariable, ] simple_vars = [ TimeVariable, DateVariable, ] class TargetAlreadyExists(FormattedError): _fmt = "%(target)s already exists, but has no .git directory." def __init__(self, target): super().__init__(target=target) class GitCommandFailed(FormattedError): _fmt = "git %(command)s failed:\n%(output)s" def __init__(self, output): super().__init__(command=self._cmd, output=output) class FetchFailed(GitCommandFailed): _cmd = "fetch" class CloneFailed(GitCommandFailed): _cmd = "clone" class CheckoutFailed(GitCommandFailed): _cmd = "checkout" class MergeFailed(GitCommandFailed): _cmd = "merge" # Some default configuration to make writing recipes more pleasant. insteadof = { "lp:": "https://git.launchpad.net/" } def pull_or_clone(base_branch, target_path): """Make target_path match base_branch, either by pulling or by cloning.""" base_branch.path = target_path if os.path.exists(target_path) and not os.listdir(target_path): os.rmdir(target_path) if not os.path.exists(target_path): os.makedirs(target_path) base_branch.git_call("init") for short, base in insteadof.items(): base_branch.git_call("config", "url.%s.insteadOf" % base, short) elif not os.path.exists(os.path.join(target_path, ".git")): raise TargetAlreadyExists(target_path) try: fetch_branches(base_branch) except subprocess.CalledProcessError as e: raise FetchFailed(e.output) try: base_branch.resolve_commit() # Check out the commit hash directly to detach HEAD and ensure # commits (eg. by a merge instruction) don't affect substitution # variables. # If someone sneakily names a branch after a commit then all # hell will break loose (really, git? there's no way to force # checkout to interpret its argument as a commit?), but that's # their problem. base_branch.git_call("checkout", base_branch.commit) except subprocess.CalledProcessError as e: raise CheckoutFailed(e.output) def fetch_branches(child_branch): url = child_branch.url parsed_url = urlparse(url) if not parsed_url.scheme and not parsed_url.path.startswith("/"): url = os.path.abspath(url) # Fetch the remote HEAD. This may not exist, which is OK as long as the # recipe uses explicit branch names. try: child_branch.git_call( "fetch", url, "HEAD:refs/remotes/%s/HEAD" % child_branch.remote_name, silent=True) except subprocess.CalledProcessError as e: logging.info(e.output) logging.info( "Failed to fetch HEAD; recipe instructions for this repository " "that do not specify a branch name will fail.") # Fetch all remote branches and (implicitly) any tags that reference # commits in those refs. Tags that aren't on a branch won't be fetched. child_branch.git_call( "fetch", url, "refs/heads/*:refs/remotes/%s/*" % child_branch.remote_name) @lru_cache(maxsize=1) def _git_version(): raw_git_version = subprocess.check_output( ["dpkg-query", "-W", "-f", "${Version}", "git"], universal_newlines=True) return debian_support.Version(raw_git_version) def merge_branch(child_branch, target_path): """Merge the branch specified by `child_branch`. :param child_branch: A `RecipeBranch` identifying the branch and commit to merge from. :param target_path: The tree to merge into. """ child_branch.path = target_path fetch_branches(child_branch) try: child_branch.resolve_commit() cmd = ["merge", "--commit"] if _git_version() >= "1:2.9.0": cmd.append("--allow-unrelated-histories") cmd.extend(["-m", "Merge %s" % child_branch.get_revspec()]) cmd.append(child_branch.commit) child_branch.git_call(*cmd) except subprocess.CalledProcessError as e: raise MergeFailed(e.output) def nest_part_branch(child_branch, target_path, subpath, target_subdir=None): """Nest the branch subdirectory specified by `child_branch`. :param child_branch: A `RecipeBranch` identifying the branch and commit to merge from. :param target_path: The tree to merge into. :param subpath: Only merge files from `child_branch` that are from this path. For example, subpath="/debian" will only merge changes from that directory. :param target_subdir: Optional directory in `target_path` to merge that subpath into. Defaults to the basename of `subpath`. """ subpath = subpath.lstrip("/") if target_subdir is None: target_subdir = os.path.basename(subpath) # XXX should handle updating as well assert not os.path.exists(target_subdir) child_branch.path = target_path fetch_branches(child_branch) child_branch.resolve_commit() child_branch.git_call( "read-tree", "--prefix", target_subdir, "-u", child_branch.commit + ":" + subpath) def _build_inner_tree(base_branch, target_path): revision_of = "" if base_branch.revspec is not None: revision_of = "revision '%s' of " % base_branch.revspec logging.info( "Retrieving %s'%s' to put at '%s'." % (revision_of, base_branch.url, target_path)) pull_or_clone(base_branch, target_path) base_branch.resolve_commit() for instruction in base_branch.child_branches: instruction.apply(target_path) def _resolve_revisions_recurse(new_branch, substitute_branch_vars, if_changed_from=None): changed = False if substitute_branch_vars is not None: # XXX need to make sure new_branch has been fetched new_branch.resolve_commit() substitute_branch_vars(new_branch) if (if_changed_from is not None and (new_branch.revspec is not None or if_changed_from.revspec is not None)): if if_changed_from.revspec is not None: # XXX resolve revspec changed_commit = if_changed_from.revspec else: changed_commit = new_branch.commit if new_branch.commit != changed_commit: changed = True for index, instruction in enumerate(new_branch.child_branches): child_branch = instruction.recipe_branch if_changed_child = None if if_changed_from is not None: if_changed_child = ( if_changed_from.child_branches[index].recipe_branch) if child_branch is not None: child_changed = _resolve_revisions_recurse( child_branch, substitute_branch_vars, if_changed_from=if_changed_child) if child_changed: changed = child_changed return changed def resolve_revisions(base_branch, if_changed_from=None, substitute_branch_vars=None): """Resolve all the unknowns in `base_branch`. This walks the `RecipeBranch` and calls `substitute_branch_vars` for each child branch. If `if_changed_from` is not None then it should be a second `RecipeBranch` to compare `base_branch` against. If the shape or the commit IDs differ then the function will return True. :param base_branch: The `RecipeBranch` we plan to build. :param if_changed_from: The `RecipeBranch` that we want to compare against. :param substitute_branch_vars: Callable called for each `RecipeBranch`. :return: False if `if_changed_from` is not None, and the shape and commits of the two branches are the same. True otherwise. """ changed = False if if_changed_from is not None: changed = base_branch.different_shape_to(if_changed_from) if_changed_from_revisions = None if changed else if_changed_from if substitute_branch_vars is not None: real_substitute_branch_vars = ( lambda child_branch: substitute_branch_vars( base_branch, child_branch)) else: real_substitute_branch_vars = None changed_revisions = _resolve_revisions_recurse( base_branch, real_substitute_branch_vars, if_changed_from=if_changed_from_revisions) if not changed: changed = changed_revisions if if_changed_from is not None and not changed: return False return True def build_tree(base_branch, target_path): logging.info("Building tree.") _build_inner_tree(base_branch, target_path) class ChildBranch: """A child branch in a recipe. If the nest path is not None it is the path relative to the recipe branch where the child branch should be placed. If it is None then the child branch should be merged instead of nested. """ can_have_children = False def __init__(self, recipe_branch, nest_path=None): self.recipe_branch = recipe_branch self.nest_path = nest_path def apply(self, target_path): raise NotImplementedError(self.apply) def as_tuple(self): return (self.recipe_branch, self.nest_path) def _get_commit_part(self): if self.recipe_branch.commit is not None: return " git-commit:%s" % self.recipe_branch.commit elif self.recipe_branch.revspec is not None: return " %s" % self.recipe_branch.revspec else: return "" def __repr__(self): return "<%s %r>" % (self.__class__.__name__, self.nest_path) class CommandInstruction(ChildBranch): def apply(self, target_path): # it's a command logging.info("Running '%s' in '%s'." % (self.nest_path, target_path)) subprocess.check_call( self.nest_path, cwd=target_path, shell=True, stdin=subprocess.PIPE) def as_text(self): return "%s %s" % (RUN_INSTRUCTION, self.nest_path) class MergeInstruction(ChildBranch): def apply(self, target_path): revision_of = "" if self.recipe_branch.revspec is not None: revision_of = "revision '%s' of " % self.recipe_branch.revspec logging.info( "Merging %s'%s' in to '%s'." % (revision_of, self.recipe_branch.url, target_path)) merge_branch(self.recipe_branch, target_path) def as_text(self): commit_part = self._get_commit_part() return "%s %s %s%s" % ( MERGE_INSTRUCTION, self.recipe_branch.name, self.recipe_branch.url, commit_part) def __repr__(self): return "<%s %r>" % (self.__class__.__name__, self.recipe_branch.name) class NestPartInstruction(ChildBranch): def __init__(self, recipe_branch, subpath, target_subdir): ChildBranch.__init__(self, recipe_branch) self.subpath = subpath self.target_subdir = target_subdir def apply(self, target_path): nest_part_branch( self.recipe_branch, target_path, self.subpath, target_subdir=self.target_subdir) def as_text(self): commit_part = self._get_commit_part() if commit_part: target_subdir = self.target_subdir if target_subdir is None: target_subdir = self.subpath target_commit_part = " %s%s" % (target_subdir, commit_part) elif self.target_subdir is not None: target_commit_part = " %s" % self.target_subdir else: target_commit_part = "" return "%s %s %s %s%s" % ( NEST_PART_INSTRUCTION, self.recipe_branch.name, self.recipe_branch.url, self.subpath, target_commit_part) class NestInstruction(ChildBranch): can_have_children = True def apply(self, target_path): _build_inner_tree( self.recipe_branch, target_path=os.path.join(target_path, self.nest_path)) def as_text(self): commit_part = self._get_commit_part() return "%s %s %s %s%s" % ( NEST_INSTRUCTION, self.recipe_branch.name, self.recipe_branch.url, self.nest_path, commit_part) def __repr__(self): return "<%s %r>" % (self.__class__.__name__, self.recipe_branch.name) class RecipeBranch: """A nested structure that represents a Recipe. A RecipeBranch has a name and a url (the name can be None for the root branch), and optionally child branches that are either merged or nested. The `child_branches` attribute is a list of tuples of `ChildBranch` objects. The commit attribute records the commit that the `url` and `revspec` resolved to when the `RecipeBranch` was built, or None if it has not been built. :ivar commit: After this recipe branch has been built, this is set to the commit object name that was merged/nested from the branch at `self.url`. """ def __init__(self, name, url, revspec=None): """Create a `RecipeBranch`. :param name: The name for the branch, or None if it is the root. :param url: The URL from which to retrieve the branch. :param revspec: A revision (as in `git rev-parse`) for the commit to use, or None (the default) to use `HEAD`. """ self.name = name self.url = url self.revspec = revspec self.child_branches = [] self.commit = None self.path = None @property def remote_name(self): if self.name is None: return 'source' return 'source-%s' % self.name def _get_git_path(self): if self.path is not None: return self.path elif not urlparse(self.url).scheme: return self.url else: # XXX more specific exception type raise Exception( "Repository at %s has not been cloned yet" % self.url) def git_call(self, *args, **kwargs): cmd = ["git", "-C", self._get_git_path()] + list(args) silent = kwargs.pop("silent", False) # This allows any raised CalledProcessError to contain the output. # Writing to stdout/stderr depending on return code is an # approximation, but preserves interleaving and should do the job # well enough. try: output = subprocess.check_output( cmd, stderr=subprocess.STDOUT, universal_newlines=True, **kwargs) if not silent: sys.stdout.write(output) except subprocess.CalledProcessError as e: if not silent: sys.stderr.write(e.output) raise def git_output(self, *args, **kwargs): return subprocess.check_output( ["git", "-C", self._get_git_path()] + list(args), universal_newlines=True, **kwargs) def get_revspec(self): return self.revspec if self.revspec is not None else "HEAD" def resolve_commit(self): """Resolve the commit for this branch.""" # Capturing stderr is a bit dodgy, but it's the most convenient way # to capture it for any exceptions. We know that git rev-parse does # not write to stderr on success. try: self.commit = self.git_output( "rev-parse", "%s/%s" % (self.remote_name, self.get_revspec()), stderr=subprocess.STDOUT).rstrip("\n") return except subprocess.CalledProcessError: pass # Not a remote-prefixed ref. Try a global search. # XXX: This allows cross-branch pollution, but we don't have # much choice without reimplementing rev-parse ourselves. self.commit = self.git_output( "rev-parse", self.get_revspec(), stderr=subprocess.STDOUT).rstrip("\n") def merge_branch(self, branch): """Merge a child branch into this one. :param branch: The `RecipeBranch` to merge. """ self.child_branches.append(MergeInstruction(branch)) def nest_part_branch(self, branch, subpath=None, target_subdir=None): """Merge subdir of a child branch into this one. :param branch: The `RecipeBranch` to merge. :param subpath: Only merge files from `branch` that are from this path. For example, subpath="/debian" will only merge changes from that directory. :param target_subdir: Optional directory in the target tree to merge that subpath into. Defaults to the basename of `subpath`. """ self.child_branches.append( NestPartInstruction(branch, subpath, target_subdir)) def nest_branch(self, location, branch): """Nest a child branch into this one. :param location: The relative path at which this branch should be nested. :param branch: The `RecipeBranch` to nest. """ if any(location == b.nest_path for b in self.child_branches): raise AssertionError( "%s already has a branch nested there" % location) self.child_branches.append(NestInstruction(branch, location)) def run_command(self, command): """Set a command to be run. :param command: The command to be run. """ self.child_branches.append(CommandInstruction(None, command)) def different_shape_to(self, other_branch): """Test whether the name, url, and child_branches are the same.""" if self.name != other_branch.name: return True if self.url != other_branch.url: return True if len(self.child_branches) != len(other_branch.child_branches): return True for index, instruction in enumerate(self.child_branches): child_branch = instruction.recipe_branch nest_location = instruction.nest_path other_instruction = other_branch.child_branches[index] other_child_branch = other_instruction.recipe_branch other_nest_location = other_instruction.nest_path if nest_location != other_nest_location: return True if ((child_branch is None and other_child_branch is not None) or (child_branch is not None and other_child_branch is None)): return True # If child_branch is None then other_child_branch must be None # too, meaning that they are both run instructions. We would # compare their nest locations (commands), but that has already # been done, so just guard. if (child_branch is not None and child_branch.different_shape_to(other_child_branch)): return True return False def iter_all_instructions(self): """Iter over all instructions under this branch.""" for instruction in self.child_branches: yield instruction child_branch = instruction.recipe_branch if child_branch is None: continue for instruction in child_branch.iter_all_instructions(): yield instruction def iter_all_branches(self): """Iterate over all branches.""" yield self for instruction in self.child_branches: child_branch = instruction.recipe_branch if child_branch is None: continue for subbranch in child_branch.iter_all_branches(): yield subbranch def lookup_branch(self, name): """Look up a branch by its name.""" for branch in self.iter_all_branches(): if branch.name == name: return branch else: raise KeyError(name) def list_branch_names(self): """List all of the branch names under this one. :return: A list of the branch names. :rtype: list(str) """ return [ branch.name for branch in self.iter_all_branches() if branch.name is not None] def __repr__(self): return "<%s %r>" % (self.__class__.__name__, self.name) class BaseRecipeBranch(RecipeBranch): """The `RecipeBranch` that is at the root of a recipe.""" def __init__(self, url, deb_version, format_version, revspec=None): """Create a `BaseRecipeBranch`. :param deb_version: The template to use for the version number. Should be None for anything except the root branch. """ super().__init__(None, url, revspec=revspec) self.deb_version = deb_version self.format_version = format_version if not urlparse(url).scheme: self.path = url def _add_child_branches_to_manifest(self, child_branches, indent_level): manifest = "" for instruction in child_branches: manifest += "%s%s\n" % (" " * indent_level, instruction.as_text()) if instruction.can_have_children: manifest += self._add_child_branches_to_manifest( instruction.recipe_branch.child_branches, indent_level + 1) return manifest def __str__(self): return self.get_recipe_text(validate=True) def get_recipe_text(self, validate=False): manifest = "# git-build-recipe format %s" % str(self.format_version) if self.deb_version is not None: # TODO: should we store the expanded version that was used? manifest += " deb-version %s" % self.deb_version manifest += "\n" if self.commit is not None: manifest += "%s git-commit:%s\n" % (self.url, self.commit) elif self.revspec is not None: manifest += "%s %s\n" % (self.url, self.revspec) else: manifest += "%s\n" % self.url manifest += self._add_child_branches_to_manifest( self.child_branches, 0) if validate: # Ensure that the recipe can be parsed. # TODO: write a function that compares the result of this parse # with the branch that we built it from. RecipeParser(manifest).parse() return manifest class RecipeParseError(FormattedError): _fmt = "Error parsing %(filename)s:%(line)s:%(char)s: %(problem)s." def __init__(self, filename, line, char, problem): super().__init__( filename=filename, line=line, char=char, problem=problem) class InstructionParseError(RecipeParseError): _fmt = RecipeParseError._fmt + "\nUsage: %(usage)s" def __init__(self, filename, line, char, problem, instruction): super().__init__(filename, line, char, problem) self.usage = USAGE[instruction] class ForbiddenInstructionError(RecipeParseError): def __init__(self, filename, line, char, problem, instruction_name=None): super().__init__(filename, line, char, problem) self.instruction_name = instruction_name class RecipeParser: """Parse a recipe. The parse() method is probably the only one that interests you. """ whitespace_chars = " \t" eol_char = "\n" digit_chars = ("0", "1", "2", "3", "4", "5", "6", "7", "8", "9") NEWEST_VERSION = 0.4 def __init__(self, f): """Create a `RecipeParser`. :param f: Either the recipe as a string, or a file-like object to take it from. """ if getattr(f, "read", None) is not None: self.text = f.read() else: self.text = f self.filename = None if hasattr(f, "name"): self.filename = f.name if self.filename is None: self.filename = "recipe" def parse(self, permitted_instructions=None): """Parse the recipe. :param permitted_instructions: A list of instructions that you want to allow. Defaults to None allowing them all. :type permitted_instructions: list(str) or None :return: A `RecipeBranch` representing the recipe. """ self.lines = self.text.split("\n") self.index = 0 self.line_index = 0 self.current_line = self.lines[self.line_index] self.current_indent_level = 0 self.seen_nicks = set() self.seen_paths = {".": 1} version, deb_version = self.parse_header() self.version = version last_instruction = None active_branches = [] last_branch = None while self.line_index < len(self.lines): if self.is_blankline(): self.new_line() continue comment = self.parse_comment_line() if comment is not None: self.new_line() continue old_indent_level = self.parse_indent() if old_indent_level is not None: if (old_indent_level < self.current_indent_level and last_instruction != NEST_INSTRUCTION): self.throw_parse_error( "Not allowed to indent unless after a '%s' line" % NEST_INSTRUCTION) if old_indent_level < self.current_indent_level: active_branches.append(last_branch) else: unindent = self.current_indent_level - old_indent_level active_branches = active_branches[:unindent] if last_instruction is None: url = self.take_to_whitespace("branch to start from") revspec = self.parse_optional_revspec() self.new_line() last_branch = BaseRecipeBranch( url, deb_version, self.version, revspec=revspec) active_branches = [last_branch] last_instruction = "" else: instruction = self.parse_instruction( permitted_instructions=permitted_instructions) if instruction == RUN_INSTRUCTION: self.parse_whitespace( "the command", instruction=instruction) command = self.take_to_newline().strip() self.new_line() active_branches[-1].run_command(command) else: branch_id = self.parse_branch_id(instruction) url = self.parse_branch_url(instruction) if instruction == NEST_INSTRUCTION: location = self.parse_branch_location(instruction) if instruction == NEST_PART_INSTRUCTION: path = self.parse_subpath(instruction) target_subdir = self.parse_optional_path() if target_subdir == "": target_subdir = None revspec = None else: revspec = self.parse_optional_revspec() else: revspec = self.parse_optional_revspec() self.new_line(instruction) last_branch = RecipeBranch(branch_id, url, revspec=revspec) if instruction == NEST_INSTRUCTION: active_branches[-1].nest_branch(location, last_branch) elif instruction == MERGE_INSTRUCTION: active_branches[-1].merge_branch(last_branch) elif instruction == NEST_PART_INSTRUCTION: active_branches[-1].nest_part_branch( last_branch, path, target_subdir) last_instruction = instruction if len(active_branches) == 0: self.throw_parse_error("Empty recipe") return active_branches[0] def parse_header(self): self.parse_char("#") # Try git-build-recipe last even though it's now the preferred form, # in order that user-visible error messages look sensible. try: self.parse_word("bzr-builder", require_whitespace=False) except RecipeParseError: self.parse_word("git-build-recipe", require_whitespace=False) self.parse_word("format") version, version_str = self.peek_float("format version") if version > self.NEWEST_VERSION: self.throw_parse_error("Unknown format: '%s'" % str(version)) self.take_chars(len(version_str)) deb_version = self.parse_optional_deb_version() self.new_line() return version, deb_version def parse_instruction(self, permitted_instructions=None): if self.version < 0.2: options = (MERGE_INSTRUCTION, NEST_INSTRUCTION) options_str = "'%s' or '%s'" % options elif self.version < 0.3: options = (MERGE_INSTRUCTION, NEST_INSTRUCTION, RUN_INSTRUCTION) options_str = "'%s', '%s', or '%s'" % options else: options = ( MERGE_INSTRUCTION, NEST_INSTRUCTION, NEST_PART_INSTRUCTION, RUN_INSTRUCTION) options_str = "'%s', '%s', '%s', or '%s'" % options instruction = self.peek_to_whitespace() if instruction is None: self.throw_parse_error( "End of line while looking for %s" % options_str) if instruction in options: if permitted_instructions is not None: if instruction not in permitted_instructions: self.throw_parse_error( "The '%s' instruction is forbidden" % instruction, cls=ForbiddenInstructionError, instruction_name=instruction) self.take_chars(len(instruction)) return instruction self.throw_parse_error( "Expecting %s, got '%s'" % (options_str, instruction)) def parse_branch_id(self, instruction): self.parse_whitespace("the branch id", instruction=instruction) branch_id = self.peek_to_whitespace() if branch_id is None: self.throw_parse_error( "End of line while looking for the branch id", cls=InstructionParseError, instruction=instruction) if branch_id in self.seen_nicks: self.throw_parse_error( "'%s' was already used to identify a branch." % branch_id) self.take_chars(len(branch_id)) self.seen_nicks.add(branch_id) return branch_id def parse_branch_url(self, instruction): self.parse_whitespace("the branch url", instruction=instruction) return self.take_to_whitespace("the branch url", instruction) def parse_branch_location(self, instruction): # FIXME: Needs a better term self.parse_whitespace("the location to nest") location = self.peek_to_whitespace() if location is None: self.throw_parse_error( "End of line while looking for the location to nest", cls=InstructionParseError, instruction=instruction) norm_location = os.path.normpath(location) if norm_location in self.seen_paths: self.throw_parse_error( "The path '%s' is a duplicate of the one used on line %d." % ( location, self.seen_paths[norm_location]), cls=InstructionParseError, instruction=instruction) if os.path.isabs(norm_location): self.throw_parse_error( "Absolute paths are not allowed: %s" % location, cls=InstructionParseError, instruction=instruction) if norm_location.startswith(".."): self.throw_parse_error( "Paths outside the current directory are not allowed: %s" % ( location), cls=InstructionParseError, instruction=instruction) self.take_chars(len(location)) self.seen_paths[norm_location] = self.line_index + 1 return location def parse_subpath(self, instruction): self.parse_whitespace("the subpath to merge", instruction=instruction) return self.take_to_whitespace("the subpath to merge", instruction) def parse_revspec(self): self.parse_whitespace("the revspec") return self.take_to_whitespace("the revspec") def parse_optional_deb_version(self): self.parse_whitespace("'deb-version'", require=False) actual = self.peek_to_whitespace() if actual is None: # End of line, no version return None if actual != "deb-version": self.throw_expecting_error("deb-version", actual) self.take_chars(len("deb-version")) self.parse_whitespace("a value for 'deb-version'") return self.take_to_whitespace("a value for 'deb-version'") def parse_optional_revspec(self): self.parse_whitespace(None, require=False) revspec = self.peek_to_whitespace() if revspec is not None: self.take_chars(len(revspec)) return revspec def parse_optional_path(self): self.parse_whitespace(None, require=False) path = self.peek_to_whitespace() if path is not None: self.take_chars(len(path)) return path def throw_parse_error(self, problem, cls=None, **kwargs): if cls is None: cls = RecipeParseError raise cls( self.filename, self.line_index + 1, self.index + 1, problem, **kwargs) def throw_expecting_error(self, expected, actual): self.throw_parse_error("Expecting '%s', got '%s'" % (expected, actual)) def throw_eol(self, expected): self.throw_parse_error("End of line while looking for '%s'" % expected) def new_line(self, instruction=None): # Jump over any whitespace self.parse_whitespace(None, require=False) remaining = self.peek_to_whitespace() if remaining is not None: kwargs = {} if instruction is not None: kwargs = { "cls": InstructionParseError, "instruction": instruction, } self.throw_parse_error( "Expecting the end of the line, got '%s'" % remaining, **kwargs) self.index = 0 self.line_index += 1 if self.line_index >= len(self.lines): self.current_line = None else: self.current_line = self.lines[self.line_index] def is_blankline(self): whitespace = self.peek_whitespace() if whitespace is None: return True return self.peek_char(skip=len(whitespace)) is None def take_char(self): if self.index >= len(self.current_line): return None self.index += 1 return self.current_line[self.index-1] def take_chars(self, num): ret = "" for i in range(num): char = self.take_char() if char is None: return None ret += char return ret def peek_char(self, skip=0): if self.index + skip >= len(self.current_line): return None return self.current_line[self.index + skip] def parse_char(self, char): actual = self.peek_char() if actual is None: self.throw_eol(char) if actual == char: self.take_char() return char self.throw_expecting_error(char, actual) def parse_indent(self): """Parse the indent from the start of the line.""" # FIXME: should just peek the whitespace new_indent = self.parse_whitespace(None, require=False) # FIXME: These checks should probably come after we check whether # any change in indent is legal at this point: # "Indents of 3 spaces aren't allowed" -> make it 2 spaces # -> "oh, you aren't allowed to indent at that point anyway" if "\t" in new_indent: self.throw_parse_error("Indents may not be done by tabs") if (len(new_indent) % 2 != 0): self.throw_parse_error("Indent not a multiple of two spaces") new_indent_level = len(new_indent) // 2 if new_indent_level != self.current_indent_level: old_indent_level = self.current_indent_level self.current_indent_level = new_indent_level if (new_indent_level > old_indent_level and new_indent_level - old_indent_level != 1): self.throw_parse_error( "Indented by more than two spaces at once") return old_indent_level return None def parse_whitespace(self, looking_for, require=True, instruction=None): if require: actual = self.peek_char() if actual is None: kwargs = {} if instruction is not None: kwargs = { "cls": InstructionParseError, "instruction": instruction, } self.throw_parse_error( "End of line while looking for %s" % looking_for, **kwargs) if actual not in self.whitespace_chars: self.throw_parse_error( "Expecting whitespace before %s, got '%s'." % (looking_for, actual)) ret = "" actual = self.peek_char() while actual is not None and actual in self.whitespace_chars: self.take_char() ret += actual actual = self.peek_char() return ret def peek_whitespace(self): ret = "" char = self.peek_char() if char is None: return char count = 0 while char is not None and char in self.whitespace_chars: ret += char count += 1 char = self.peek_char(skip=count) return ret def parse_word(self, expected, require_whitespace=True): self.parse_whitespace("'%s'" % expected, require=require_whitespace) length = len(expected) actual = self.peek_to_whitespace() if actual == expected: self.take_chars(length) return expected if actual is None: self.throw_eol(expected) self.throw_expecting_error(expected, actual) def peek_to_whitespace(self): ret = "" char = self.peek_char() if char is None: return char count = 0 while char is not None and char not in self.whitespace_chars: ret += char count += 1 char = self.peek_char(skip=count) return ret def take_to_whitespace(self, looking_for, instruction=None): text = self.peek_to_whitespace() if text is None: kwargs = {} if instruction is not None: kwargs = { "cls": InstructionParseError, "instruction": instruction, } self.throw_parse_error( "End of line while looking for %s" % looking_for, **kwargs) self.take_chars(len(text)) return text def peek_float(self, looking_for): self.parse_whitespace(looking_for) ret = self._parse_integer() conv_fn = int if ret == "": self.throw_parse_error( "Expecting a float, got '%s'" % self.peek_to_whitespace()) if self.peek_char(skip=len(ret)) == ".": conv_fn = float ret2 = self._parse_integer(skip=(len(ret) + 1)) if ret2 == "": self.throw_parse_error( "Expecting a float, got '%s'" % self.peek_to_whitespace()) ret += "." + ret2 try: fl = conv_fn(ret) except ValueError: self.throw_parse_error("Expecting a float, got '%s'" % ret) return (fl, ret) def _parse_integer(self, skip=0): i = skip ret = "" while True: char = self.peek_char(skip=i) if char not in self.digit_chars: break ret += char i += 1 return ret def parse_integer(self): ret = self._parse_integer() if ret == "": self.throw_parse_error( "Expected an integer, found %s" % self.peek_to_whitespace()) self.take_chars(len(ret)) return ret def take_to_newline(self): text = self.current_line[self.index:] self.index += len(text) return text def parse_comment_line(self): whitespace = self.peek_whitespace() if whitespace is None: return "" if self.peek_char(skip=len(whitespace)) is None: return "" if self.peek_char(skip=len(whitespace)) != "#": return None self.parse_whitespace(None, require=False) comment = self.current_line[self.index:] self.index += len(comment) return comment def parse_recipe(recipe_file, safe=False): parser = RecipeParser(recipe_file) if safe: permitted_instructions = SAFE_INSTRUCTIONS else: permitted_instructions = None return parser.parse(permitted_instructions=permitted_instructions)