| # -*- coding: utf-8 -*- |
| # |
| # QAPI schema parser |
| # |
| # Copyright IBM, Corp. 2011 |
| # Copyright (c) 2013-2019 Red Hat Inc. |
| # |
| # Authors: |
| # Anthony Liguori <aliguori@us.ibm.com> |
| # Markus Armbruster <armbru@redhat.com> |
| # Marc-André Lureau <marcandre.lureau@redhat.com> |
| # Kevin Wolf <kwolf@redhat.com> |
| # |
| # This work is licensed under the terms of the GNU GPL, version 2. |
| # See the COPYING file in the top-level directory. |
| |
| from collections import OrderedDict |
| import os |
| import re |
| from typing import ( |
| Dict, |
| List, |
| Optional, |
| Set, |
| Union, |
| ) |
| |
| from .common import must_match |
| from .error import QAPISemError, QAPISourceError |
| from .source import QAPISourceInfo |
| |
| |
| # Return value alias for get_expr(). |
| _ExprValue = Union[List[object], Dict[str, object], str, bool] |
| |
| |
| class QAPIParseError(QAPISourceError): |
| """Error class for all QAPI schema parsing errors.""" |
| def __init__(self, parser: 'QAPISchemaParser', msg: str): |
| col = 1 |
| for ch in parser.src[parser.line_pos:parser.pos]: |
| if ch == '\t': |
| col = (col + 7) % 8 + 1 |
| else: |
| col += 1 |
| super().__init__(parser.info, msg, col) |
| |
| |
| class QAPISchemaParser: |
| """ |
| Parse QAPI schema source. |
| |
| Parse a JSON-esque schema file and process directives. See |
| qapi-code-gen.txt section "Schema Syntax" for the exact syntax. |
| Grammatical validation is handled later by `expr.check_exprs()`. |
| |
| :param fname: Source file name. |
| :param previously_included: |
| The absolute names of previously included source files, |
| if being invoked from another parser. |
| :param incl_info: |
| `QAPISourceInfo` belonging to the parent module. |
| ``None`` implies this is the root module. |
| |
| :ivar exprs: Resulting parsed expressions. |
| :ivar docs: Resulting parsed documentation blocks. |
| |
| :raise OSError: For problems reading the root schema document. |
| :raise QAPIError: For errors in the schema source. |
| """ |
| def __init__(self, |
| fname: str, |
| previously_included: Optional[Set[str]] = None, |
| incl_info: Optional[QAPISourceInfo] = None): |
| self._fname = fname |
| self._included = previously_included or set() |
| self._included.add(os.path.abspath(self._fname)) |
| self.src = '' |
| |
| # Lexer state (see `accept` for details): |
| self.info = QAPISourceInfo(self._fname, incl_info) |
| self.tok: Union[None, str] = None |
| self.pos = 0 |
| self.cursor = 0 |
| self.val: Optional[Union[bool, str]] = None |
| self.line_pos = 0 |
| |
| # Parser output: |
| self.exprs: List[Dict[str, object]] = [] |
| self.docs: List[QAPIDoc] = [] |
| |
| # Showtime! |
| self._parse() |
| |
| def _parse(self) -> None: |
| """ |
| Parse the QAPI schema document. |
| |
| :return: None. Results are stored in ``.exprs`` and ``.docs``. |
| """ |
| cur_doc = None |
| |
| # May raise OSError; allow the caller to handle it. |
| with open(self._fname, 'r', encoding='utf-8') as fp: |
| self.src = fp.read() |
| if self.src == '' or self.src[-1] != '\n': |
| self.src += '\n' |
| |
| # Prime the lexer: |
| self.accept() |
| |
| # Parse until done: |
| while self.tok is not None: |
| info = self.info |
| if self.tok == '#': |
| self.reject_expr_doc(cur_doc) |
| for cur_doc in self.get_doc(info): |
| self.docs.append(cur_doc) |
| continue |
| |
| expr = self.get_expr() |
| if not isinstance(expr, dict): |
| raise QAPISemError( |
| info, "top-level expression must be an object") |
| |
| if 'include' in expr: |
| self.reject_expr_doc(cur_doc) |
| if len(expr) != 1: |
| raise QAPISemError(info, "invalid 'include' directive") |
| include = expr['include'] |
| if not isinstance(include, str): |
| raise QAPISemError(info, |
| "value of 'include' must be a string") |
| incl_fname = os.path.join(os.path.dirname(self._fname), |
| include) |
| self.exprs.append({'expr': {'include': incl_fname}, |
| 'info': info}) |
| exprs_include = self._include(include, info, incl_fname, |
| self._included) |
| if exprs_include: |
| self.exprs.extend(exprs_include.exprs) |
| self.docs.extend(exprs_include.docs) |
| elif "pragma" in expr: |
| self.reject_expr_doc(cur_doc) |
| if len(expr) != 1: |
| raise QAPISemError(info, "invalid 'pragma' directive") |
| pragma = expr['pragma'] |
| if not isinstance(pragma, dict): |
| raise QAPISemError( |
| info, "value of 'pragma' must be an object") |
| for name, value in pragma.items(): |
| self._pragma(name, value, info) |
| else: |
| expr_elem = {'expr': expr, |
| 'info': info} |
| if cur_doc: |
| if not cur_doc.symbol: |
| raise QAPISemError( |
| cur_doc.info, "definition documentation required") |
| expr_elem['doc'] = cur_doc |
| self.exprs.append(expr_elem) |
| cur_doc = None |
| self.reject_expr_doc(cur_doc) |
| |
| @staticmethod |
| def reject_expr_doc(doc: Optional['QAPIDoc']) -> None: |
| if doc and doc.symbol: |
| raise QAPISemError( |
| doc.info, |
| "documentation for '%s' is not followed by the definition" |
| % doc.symbol) |
| |
| @staticmethod |
| def _include(include: str, |
| info: QAPISourceInfo, |
| incl_fname: str, |
| previously_included: Set[str] |
| ) -> Optional['QAPISchemaParser']: |
| incl_abs_fname = os.path.abspath(incl_fname) |
| # catch inclusion cycle |
| inf: Optional[QAPISourceInfo] = info |
| while inf: |
| if incl_abs_fname == os.path.abspath(inf.fname): |
| raise QAPISemError(info, "inclusion loop for %s" % include) |
| inf = inf.parent |
| |
| # skip multiple include of the same file |
| if incl_abs_fname in previously_included: |
| return None |
| |
| try: |
| return QAPISchemaParser(incl_fname, previously_included, info) |
| except OSError as err: |
| raise QAPISemError( |
| info, |
| f"can't read include file '{incl_fname}': {err.strerror}" |
| ) from err |
| |
| @staticmethod |
| def _pragma(name: str, value: object, info: QAPISourceInfo) -> None: |
| |
| def check_list_str(name: str, value: object) -> List[str]: |
| if (not isinstance(value, list) or |
| any(not isinstance(elt, str) for elt in value)): |
| raise QAPISemError( |
| info, |
| "pragma %s must be a list of strings" % name) |
| return value |
| |
| pragma = info.pragma |
| |
| if name == 'doc-required': |
| if not isinstance(value, bool): |
| raise QAPISemError(info, |
| "pragma 'doc-required' must be boolean") |
| pragma.doc_required = value |
| elif name == 'command-name-exceptions': |
| pragma.command_name_exceptions = check_list_str(name, value) |
| elif name == 'command-returns-exceptions': |
| pragma.command_returns_exceptions = check_list_str(name, value) |
| elif name == 'member-name-exceptions': |
| pragma.member_name_exceptions = check_list_str(name, value) |
| else: |
| raise QAPISemError(info, "unknown pragma '%s'" % name) |
| |
| def accept(self, skip_comment: bool = True) -> None: |
| """ |
| Read and store the next token. |
| |
| :param skip_comment: |
| When false, return COMMENT tokens ("#"). |
| This is used when reading documentation blocks. |
| |
| :return: |
| None. Several instance attributes are updated instead: |
| |
| - ``.tok`` represents the token type. See below for values. |
| - ``.info`` describes the token's source location. |
| - ``.val`` is the token's value, if any. See below. |
| - ``.pos`` is the buffer index of the first character of |
| the token. |
| |
| * Single-character tokens: |
| |
| These are "{", "}", ":", ",", "[", and "]". |
| ``.tok`` holds the single character and ``.val`` is None. |
| |
| * Multi-character tokens: |
| |
| * COMMENT: |
| |
| This token is not normally returned by the lexer, but it can |
| be when ``skip_comment`` is False. ``.tok`` is "#", and |
| ``.val`` is a string including all chars until end-of-line, |
| including the "#" itself. |
| |
| * STRING: |
| |
| ``.tok`` is "'", the single quote. ``.val`` contains the |
| string, excluding the surrounding quotes. |
| |
| * TRUE and FALSE: |
| |
| ``.tok`` is either "t" or "f", ``.val`` will be the |
| corresponding bool value. |
| |
| * EOF: |
| |
| ``.tok`` and ``.val`` will both be None at EOF. |
| """ |
| while True: |
| self.tok = self.src[self.cursor] |
| self.pos = self.cursor |
| self.cursor += 1 |
| self.val = None |
| |
| if self.tok == '#': |
| if self.src[self.cursor] == '#': |
| # Start of doc comment |
| skip_comment = False |
| self.cursor = self.src.find('\n', self.cursor) |
| if not skip_comment: |
| self.val = self.src[self.pos:self.cursor] |
| return |
| elif self.tok in '{}:,[]': |
| return |
| elif self.tok == "'": |
| # Note: we accept only printable ASCII |
| string = '' |
| esc = False |
| while True: |
| ch = self.src[self.cursor] |
| self.cursor += 1 |
| if ch == '\n': |
| raise QAPIParseError(self, "missing terminating \"'\"") |
| if esc: |
| # Note: we recognize only \\ because we have |
| # no use for funny characters in strings |
| if ch != '\\': |
| raise QAPIParseError(self, |
| "unknown escape \\%s" % ch) |
| esc = False |
| elif ch == '\\': |
| esc = True |
| continue |
| elif ch == "'": |
| self.val = string |
| return |
| if ord(ch) < 32 or ord(ch) >= 127: |
| raise QAPIParseError( |
| self, "funny character in string") |
| string += ch |
| elif self.src.startswith('true', self.pos): |
| self.val = True |
| self.cursor += 3 |
| return |
| elif self.src.startswith('false', self.pos): |
| self.val = False |
| self.cursor += 4 |
| return |
| elif self.tok == '\n': |
| if self.cursor == len(self.src): |
| self.tok = None |
| return |
| self.info = self.info.next_line() |
| self.line_pos = self.cursor |
| elif not self.tok.isspace(): |
| # Show up to next structural, whitespace or quote |
| # character |
| match = must_match('[^[\\]{}:,\\s\'"]+', |
| self.src[self.cursor-1:]) |
| raise QAPIParseError(self, "stray '%s'" % match.group(0)) |
| |
| def get_members(self) -> Dict[str, object]: |
| expr: Dict[str, object] = OrderedDict() |
| if self.tok == '}': |
| self.accept() |
| return expr |
| if self.tok != "'": |
| raise QAPIParseError(self, "expected string or '}'") |
| while True: |
| key = self.val |
| assert isinstance(key, str) # Guaranteed by tok == "'" |
| |
| self.accept() |
| if self.tok != ':': |
| raise QAPIParseError(self, "expected ':'") |
| self.accept() |
| if key in expr: |
| raise QAPIParseError(self, "duplicate key '%s'" % key) |
| expr[key] = self.get_expr() |
| if self.tok == '}': |
| self.accept() |
| return expr |
| if self.tok != ',': |
| raise QAPIParseError(self, "expected ',' or '}'") |
| self.accept() |
| if self.tok != "'": |
| raise QAPIParseError(self, "expected string") |
| |
| def get_values(self) -> List[object]: |
| expr: List[object] = [] |
| if self.tok == ']': |
| self.accept() |
| return expr |
| if self.tok not in tuple("{['tf"): |
| raise QAPIParseError( |
| self, "expected '{', '[', ']', string, or boolean") |
| while True: |
| expr.append(self.get_expr()) |
| if self.tok == ']': |
| self.accept() |
| return expr |
| if self.tok != ',': |
| raise QAPIParseError(self, "expected ',' or ']'") |
| self.accept() |
| |
| def get_expr(self) -> _ExprValue: |
| expr: _ExprValue |
| if self.tok == '{': |
| self.accept() |
| expr = self.get_members() |
| elif self.tok == '[': |
| self.accept() |
| expr = self.get_values() |
| elif self.tok in tuple("'tf"): |
| assert isinstance(self.val, (str, bool)) |
| expr = self.val |
| self.accept() |
| else: |
| raise QAPIParseError( |
| self, "expected '{', '[', string, or boolean") |
| return expr |
| |
| def get_doc(self, info: QAPISourceInfo) -> List['QAPIDoc']: |
| if self.val != '##': |
| raise QAPIParseError( |
| self, "junk after '##' at start of documentation comment") |
| |
| docs = [] |
| cur_doc = QAPIDoc(self, info) |
| self.accept(False) |
| while self.tok == '#': |
| assert isinstance(self.val, str) |
| if self.val.startswith('##'): |
| # End of doc comment |
| if self.val != '##': |
| raise QAPIParseError( |
| self, |
| "junk after '##' at end of documentation comment") |
| cur_doc.end_comment() |
| docs.append(cur_doc) |
| self.accept() |
| return docs |
| if self.val.startswith('# ='): |
| if cur_doc.symbol: |
| raise QAPIParseError( |
| self, |
| "unexpected '=' markup in definition documentation") |
| if cur_doc.body.text: |
| cur_doc.end_comment() |
| docs.append(cur_doc) |
| cur_doc = QAPIDoc(self, info) |
| cur_doc.append(self.val) |
| self.accept(False) |
| |
| raise QAPIParseError(self, "documentation comment must end with '##'") |
| |
| |
| class QAPIDoc: |
| """ |
| A documentation comment block, either definition or free-form |
| |
| Definition documentation blocks consist of |
| |
| * a body section: one line naming the definition, followed by an |
| overview (any number of lines) |
| |
| * argument sections: a description of each argument (for commands |
| and events) or member (for structs, unions and alternates) |
| |
| * features sections: a description of each feature flag |
| |
| * additional (non-argument) sections, possibly tagged |
| |
| Free-form documentation blocks consist only of a body section. |
| """ |
| |
| class Section: |
| def __init__(self, parser, name=None, indent=0): |
| # parser, for error messages about indentation |
| self._parser = parser |
| # optional section name (argument/member or section name) |
| self.name = name |
| self.text = '' |
| # the expected indent level of the text of this section |
| self._indent = indent |
| |
| def append(self, line): |
| # Strip leading spaces corresponding to the expected indent level |
| # Blank lines are always OK. |
| if line: |
| indent = must_match(r'\s*', line).end() |
| if indent < self._indent: |
| raise QAPIParseError( |
| self._parser, |
| "unexpected de-indent (expected at least %d spaces)" % |
| self._indent) |
| line = line[self._indent:] |
| |
| self.text += line.rstrip() + '\n' |
| |
| class ArgSection(Section): |
| def __init__(self, parser, name, indent=0): |
| super().__init__(parser, name, indent) |
| self.member = None |
| |
| def connect(self, member): |
| self.member = member |
| |
| def __init__(self, parser, info): |
| # self._parser is used to report errors with QAPIParseError. The |
| # resulting error position depends on the state of the parser. |
| # It happens to be the beginning of the comment. More or less |
| # servicable, but action at a distance. |
| self._parser = parser |
| self.info = info |
| self.symbol = None |
| self.body = QAPIDoc.Section(parser) |
| # dict mapping parameter name to ArgSection |
| self.args = OrderedDict() |
| self.features = OrderedDict() |
| # a list of Section |
| self.sections = [] |
| # the current section |
| self._section = self.body |
| self._append_line = self._append_body_line |
| |
| def has_section(self, name): |
| """Return True if we have a section with this name.""" |
| for i in self.sections: |
| if i.name == name: |
| return True |
| return False |
| |
| def append(self, line): |
| """ |
| Parse a comment line and add it to the documentation. |
| |
| The way that the line is dealt with depends on which part of |
| the documentation we're parsing right now: |
| * The body section: ._append_line is ._append_body_line |
| * An argument section: ._append_line is ._append_args_line |
| * A features section: ._append_line is ._append_features_line |
| * An additional section: ._append_line is ._append_various_line |
| """ |
| line = line[1:] |
| if not line: |
| self._append_freeform(line) |
| return |
| |
| if line[0] != ' ': |
| raise QAPIParseError(self._parser, "missing space after #") |
| line = line[1:] |
| self._append_line(line) |
| |
| def end_comment(self): |
| self._end_section() |
| |
| @staticmethod |
| def _is_section_tag(name): |
| return name in ('Returns:', 'Since:', |
| # those are often singular or plural |
| 'Note:', 'Notes:', |
| 'Example:', 'Examples:', |
| 'TODO:') |
| |
| def _append_body_line(self, line): |
| """ |
| Process a line of documentation text in the body section. |
| |
| If this a symbol line and it is the section's first line, this |
| is a definition documentation block for that symbol. |
| |
| If it's a definition documentation block, another symbol line |
| begins the argument section for the argument named by it, and |
| a section tag begins an additional section. Start that |
| section and append the line to it. |
| |
| Else, append the line to the current section. |
| """ |
| name = line.split(' ', 1)[0] |
| # FIXME not nice: things like '# @foo:' and '# @foo: ' aren't |
| # recognized, and get silently treated as ordinary text |
| if not self.symbol and not self.body.text and line.startswith('@'): |
| if not line.endswith(':'): |
| raise QAPIParseError(self._parser, "line should end with ':'") |
| self.symbol = line[1:-1] |
| # FIXME invalid names other than the empty string aren't flagged |
| if not self.symbol: |
| raise QAPIParseError(self._parser, "invalid name") |
| elif self.symbol: |
| # This is a definition documentation block |
| if name.startswith('@') and name.endswith(':'): |
| self._append_line = self._append_args_line |
| self._append_args_line(line) |
| elif line == 'Features:': |
| self._append_line = self._append_features_line |
| elif self._is_section_tag(name): |
| self._append_line = self._append_various_line |
| self._append_various_line(line) |
| else: |
| self._append_freeform(line) |
| else: |
| # This is a free-form documentation block |
| self._append_freeform(line) |
| |
| def _append_args_line(self, line): |
| """ |
| Process a line of documentation text in an argument section. |
| |
| A symbol line begins the next argument section, a section tag |
| section or a non-indented line after a blank line begins an |
| additional section. Start that section and append the line to |
| it. |
| |
| Else, append the line to the current section. |
| |
| """ |
| name = line.split(' ', 1)[0] |
| |
| if name.startswith('@') and name.endswith(':'): |
| # If line is "@arg: first line of description", find |
| # the index of 'f', which is the indent we expect for any |
| # following lines. We then remove the leading "@arg:" |
| # from line and replace it with spaces so that 'f' has the |
| # same index as it did in the original line and can be |
| # handled the same way we will handle following lines. |
| indent = must_match(r'@\S*:\s*', line).end() |
| line = line[indent:] |
| if not line: |
| # Line was just the "@arg:" header; following lines |
| # are not indented |
| indent = 0 |
| else: |
| line = ' ' * indent + line |
| self._start_args_section(name[1:-1], indent) |
| elif self._is_section_tag(name): |
| self._append_line = self._append_various_line |
| self._append_various_line(line) |
| return |
| elif (self._section.text.endswith('\n\n') |
| and line and not line[0].isspace()): |
| if line == 'Features:': |
| self._append_line = self._append_features_line |
| else: |
| self._start_section() |
| self._append_line = self._append_various_line |
| self._append_various_line(line) |
| return |
| |
| self._append_freeform(line) |
| |
| def _append_features_line(self, line): |
| name = line.split(' ', 1)[0] |
| |
| if name.startswith('@') and name.endswith(':'): |
| # If line is "@arg: first line of description", find |
| # the index of 'f', which is the indent we expect for any |
| # following lines. We then remove the leading "@arg:" |
| # from line and replace it with spaces so that 'f' has the |
| # same index as it did in the original line and can be |
| # handled the same way we will handle following lines. |
| indent = must_match(r'@\S*:\s*', line).end() |
| line = line[indent:] |
| if not line: |
| # Line was just the "@arg:" header; following lines |
| # are not indented |
| indent = 0 |
| else: |
| line = ' ' * indent + line |
| self._start_features_section(name[1:-1], indent) |
| elif self._is_section_tag(name): |
| self._append_line = self._append_various_line |
| self._append_various_line(line) |
| return |
| elif (self._section.text.endswith('\n\n') |
| and line and not line[0].isspace()): |
| self._start_section() |
| self._append_line = self._append_various_line |
| self._append_various_line(line) |
| return |
| |
| self._append_freeform(line) |
| |
| def _append_various_line(self, line): |
| """ |
| Process a line of documentation text in an additional section. |
| |
| A symbol line is an error. |
| |
| A section tag begins an additional section. Start that |
| section and append the line to it. |
| |
| Else, append the line to the current section. |
| """ |
| name = line.split(' ', 1)[0] |
| |
| if name.startswith('@') and name.endswith(':'): |
| raise QAPIParseError(self._parser, |
| "'%s' can't follow '%s' section" |
| % (name, self.sections[0].name)) |
| if self._is_section_tag(name): |
| # If line is "Section: first line of description", find |
| # the index of 'f', which is the indent we expect for any |
| # following lines. We then remove the leading "Section:" |
| # from line and replace it with spaces so that 'f' has the |
| # same index as it did in the original line and can be |
| # handled the same way we will handle following lines. |
| indent = must_match(r'\S*:\s*', line).end() |
| line = line[indent:] |
| if not line: |
| # Line was just the "Section:" header; following lines |
| # are not indented |
| indent = 0 |
| else: |
| line = ' ' * indent + line |
| self._start_section(name[:-1], indent) |
| |
| self._append_freeform(line) |
| |
| def _start_symbol_section(self, symbols_dict, name, indent): |
| # FIXME invalid names other than the empty string aren't flagged |
| if not name: |
| raise QAPIParseError(self._parser, "invalid parameter name") |
| if name in symbols_dict: |
| raise QAPIParseError(self._parser, |
| "'%s' parameter name duplicated" % name) |
| assert not self.sections |
| self._end_section() |
| self._section = QAPIDoc.ArgSection(self._parser, name, indent) |
| symbols_dict[name] = self._section |
| |
| def _start_args_section(self, name, indent): |
| self._start_symbol_section(self.args, name, indent) |
| |
| def _start_features_section(self, name, indent): |
| self._start_symbol_section(self.features, name, indent) |
| |
| def _start_section(self, name=None, indent=0): |
| if name in ('Returns', 'Since') and self.has_section(name): |
| raise QAPIParseError(self._parser, |
| "duplicated '%s' section" % name) |
| self._end_section() |
| self._section = QAPIDoc.Section(self._parser, name, indent) |
| self.sections.append(self._section) |
| |
| def _end_section(self): |
| if self._section: |
| text = self._section.text = self._section.text.strip() |
| if self._section.name and (not text or text.isspace()): |
| raise QAPIParseError( |
| self._parser, |
| "empty doc section '%s'" % self._section.name) |
| self._section = None |
| |
| def _append_freeform(self, line): |
| match = re.match(r'(@\S+:)', line) |
| if match: |
| raise QAPIParseError(self._parser, |
| "'%s' not allowed in free-form documentation" |
| % match.group(1)) |
| self._section.append(line) |
| |
| def connect_member(self, member): |
| if member.name not in self.args: |
| # Undocumented TODO outlaw |
| self.args[member.name] = QAPIDoc.ArgSection(self._parser, |
| member.name) |
| self.args[member.name].connect(member) |
| |
| def connect_feature(self, feature): |
| if feature.name not in self.features: |
| raise QAPISemError(feature.info, |
| "feature '%s' lacks documentation" |
| % feature.name) |
| self.features[feature.name].connect(feature) |
| |
| def check_expr(self, expr): |
| if self.has_section('Returns') and 'command' not in expr: |
| raise QAPISemError(self.info, |
| "'Returns:' is only valid for commands") |
| |
| def check(self): |
| |
| def check_args_section(args, info, what): |
| bogus = [name for name, section in args.items() |
| if not section.member] |
| if bogus: |
| raise QAPISemError( |
| self.info, |
| "documented member%s '%s' %s not exist" |
| % ("s" if len(bogus) > 1 else "", |
| "', '".join(bogus), |
| "do" if len(bogus) > 1 else "does")) |
| |
| check_args_section(self.args, self.info, 'members') |
| check_args_section(self.features, self.info, 'features') |
