* Add new capability to the PEG parser to type variable assignments. For instance:
```
| a[asdl_stmt_seq*]=';'.small_stmt+ [';'] NEWLINE { a }
```
* Add new sequence types from the asdl definition (automatically generated)
* Make `asdl_seq` type a generic aliasing pointer type.
* Create a new `asdl_generic_seq` for the generic case using `void*`.
* The old `asdl_seq_GET`/`ast_seq_SET` macros now are typed.
* New `asdl_seq_GET_UNTYPED`/`ast_seq_SET_UNTYPED` macros for dealing with generic sequences.
* Changes all possible `asdl_seq` types to use specific versions everywhere.
Partially revert commit ac46eb4ad6662cf6d771b20d8963658b2186c48c:
"bpo-38113: Update the Python-ast.c generator to PEP384 (gh-15957)".
Using a module state per module instance is causing subtle practical
problems.
For example, the Mercurial project replaces the __import__() function
to implement lazy import, whereas Python expected that "import _ast"
always return a fully initialized _ast module.
Add _PyAST_Fini() to clear the state at exit.
The _ast module has no state (set _astmodule.m_size to 0). Remove
astmodule_traverse(), astmodule_clear() and astmodule_free()
functions.
This program can segfault the parser by stack overflow:
```
import ast
code = "f(" + ",".join(['a' for _ in range(100000)]) + ")"
print("Ready!")
ast.parse(code)
```
the reason is that the rule for arguments has a simple recursion when collecting args:
args[expr_ty]:
[...]
| a=named_expression b=[',' c=args { c }] {
[...] }
This consolidates the handling of my_fgets return values, so that interrupts are always handled, even if they come after EOF.
I believe PyOS_StdioReadline is still buggy in that I/O errors will not result in a proper Python exception being set. However, that is a separate issue.
This will improve the debug experience if something fails in the produced AST. Previously, errors in the produced AST can be felt much later like in the garbage collector or the compiler, making debugging them much more difficult.
GCC says
```
../cpython/Parser/string_parser.c: In function ‘fstring_find_expr’:
../cpython/Parser/string_parser.c:404:93: warning: ‘cols’ may be used uninitialized in this function [-Wmaybe-uninitialized]
404 | p2->starting_col_offset = p->tok->first_lineno == p->tok->lineno ? t->col_offset + cols : cols;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
../cpython/Parser/string_parser.c:384:16: note: ‘cols’ was declared here
384 | int lines, cols;
| ^~~~
../cpython/Parser/string_parser.c:403:45: warning: ‘lines’ may be used uninitialized in this function [-Wmaybe-uninitialized]
403 | p2->starting_lineno = t->lineno + lines - 1;
| ~~~~~~~~~~~~~~~~~~^~~
../cpython/Parser/string_parser.c:384:9: note: ‘lines’ was declared here
384 | int lines, cols;
| ^~~~~
```
and, indeed, if `PyBytes_AsString` somehow fails, lines & cols will not be initialized.
Fix a crash in the _ast module: it can no longer be loaded more than
once. It now uses a global state rather than a module state.
* Move _ast module state: use a global state instead.
* Set _astmodule.m_size to -1, so the extension cannot be loaded more
than once.
Rework asdl_c.py to pass the module state to functions in
Python-ast.c, instead of using astmodulestate_global.
Handle also PyState_AddModule() failure in init_types().
This commit changes the parsing of f-string expressions with the new parser. The parser gets pre-fed with the location of the expression itself (not the f-string, which was what we were doing before). This allows us to completely skip the shifting of the AST nodes after the parsing is completed.
`GET_INVALID_TARGET` might unexpectedly return `NULL`, which if not
caught will cause a SEGFAULT. Therefore, this commit introduces a new
inline function `RAISE_SYNTAX_ERROR_INVALID_TARGET` that always
checks for `GET_INVALID_TARGET` returning NULL and can be used in
the grammar, replacing the long C ternary operation used till now.
The following error messages get produced:
- `cannot delete ...` for invalid `del` targets
- `... is an illegal 'for' target` for invalid targets in for
statements
- `... is an illegal 'with' target` for invalid targets in
with statements
Additionally, a few `cut`s were added in various places before the
invocation of the `invalid_*` rule, in order to speed things
up.
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
On Windows, #include "pyerrors.h" no longer defines "snprintf" and
"vsnprintf" macros.
PyOS_snprintf() and PyOS_vsnprintf() should be used to get portable
behavior.
Replace snprintf() calls with PyOS_snprintf() and replace vsnprintf()
calls with PyOS_vsnprintf().
This commit removes the old parser, the deprecated parser module, the old parser compatibility flags and environment variables and all associated support code and documentation.
It no longer serves a purpose (there's only one parser) and having "new" in any name will eventually look odd. Also, it impinges on a potential sub-namespace, `__new_...__`.
A line with only a line continuation character should be considered
a blank line at tokenizer level so that only a single NEWLINE token
gets emitted. The old parser was working around the issue, but the
new parser threw a `SyntaxError` for valid input. For example,
an empty line following a line continuation character was interpreted
as a `SyntaxError`.
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
my_fgets() now calls _PyOS_InterruptOccurred(tstate) to check for
pending signals, rather calling PyOS_InterruptOccurred().
my_fgets() is called with the GIL released, whereas
PyOS_InterruptOccurred() must be called with the GIL held.
test_repl: use text=True and avoid SuppressCrashReport in
test_multiline_string_parsing().
Fix my_fgets() on Windows: fgets(fp) does crash if fileno(fp) is closed.
Fix GIL usage in PyOS_Readline(): lock the GIL to set an exception.
Pass tstate to my_fgets() and _PyOS_WindowsConsoleReadline(). Cleanup
these functions.
These are like keywords but they only work in context; they are not reserved except when there is an exact match.
This would enable things like match statements without reserving `match` (which would be bad for the `re.match()` function and probably lots of other places).
Automerge-Triggered-By: @gvanrossum
When a `SyntaxError` in the expression part of a fstring is found,
the filename attribute of the `SyntaxError` is always `<fstring>`.
With this commit, it gets changed to always have the name of the file
the fstring resides in.
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
The error message, generated for a non-parenthesized generator expression
in function calls, was still the generic `invalid syntax`, when the generator expression wasn't appearing as the first argument in the call. With this patch, even on input like `f(a, b, c for c in d, e)`, the correct error message gets produced.
- Switch from getopt to argparse.
- Removed the limitation of not being able to produce both C and H simultaneously.
This will make it run faster since it parses the asdl definition once and uses the generated tree to generate both the header and the C source.
The following improvements are implemented in this commit:
- `p->error_indicator` is set, in case malloc or realloc fail.
- Avoid memory leaks in the case that realloc fails.
- Call `PyErr_NoMemory()` instead of `PyErr_Format()`, because it requires no memory.
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
This commit fixes the new parser to disallow invalid targets in the
following scenarios:
- Augmented assignments must only accept a single target (Name,
Attribute or Subscript), but no tuples or lists.
- `except` clauses should only accept a single `Name` as a target.
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
This commit fixes SyntaxError locations when the caret is not displayed,
by doing the following:
- `col_number` always gets set to the location of the offending
node/expr. When no caret is to be displayed, this gets achieved
by setting the object holding the error line to None.
- Introduce a new function `_PyPegen_raise_error_known_location`,
which can be called, when an arbitrary `lineno`/`col_offset`
needs to be passed. This function then gets used in the grammar
(through some new macros and inline functions) so that SyntaxError
locations of the new parser match that of the old.
With the new parser, the error message contains always the trailing
newlines, causing the comparison of the repr of the error messages
in codeop to fail. This commit makes the new parser mirror the old parser's
behaviour regarding trailing newlines.
This is for the C generator:
- Disallow rule and variable names starting with `_`
- Rename most local variable names generated by the parser to start with `_`
Exceptions:
- Renaming `p` to `_p` will be a separate PR
- There are still some names that might clash, e.g.
- anything starting with `Py`
- C reserved words (`if` etc.)
- Macros like `EXTRA` and `CHECK`
When parsing something like `f(g()=2)`, where the name of a default arg
is not a NAME, but an arbitrary expression, a specialised error message
is emitted.
When parsing a string with an invalid escape, the old parser used to
point to the beginning of the invalid string. This commit changes the new
parser to match that behaviour, since it's currently pointing to the
end of the string (or to be more precise, to the beginning of the next
token).
Due to backwards compatibility concerns regarding keywords immediately followed by a string without whitespace between them (like in `bg="#d00" if clear else"#fca"`) will fail to parse,
commit 41d5b94af4 has to be reverted.
When parsing things like `def f(*): pass` the old parser used to output `SyntaxError: named arguments must follow bare *`, which the new parser wasn't able to do.
Due to PyErr_Occurred not being called at the beginning of each rule, we need to set the error indicator, so that rules do not get expanded after an exception has been thrown
This commit makes both APIs more consistent by doing the following:
- Remove the `PyPegen_CodeObjectFrom*` functions, which weren't used
and will probably not be needed. Functions like `Py_CompileStringObject`
can be used instead.
- Include a `const char *filename` parameter in `PyPegen_ASTFromString`.
- Rename `PyPegen_ASTFromFile` to `PyPegen_ASTFromFilename`, because
its signature is not the same with `PyParser_ASTFromFile`.
`ast.parse` and `compile` support a `feature_version` parameter that
tells the parser to parse the input string, as if it were written in
an older Python version.
The `feature_version` is propagated to the tokenizer, which uses it
to handle the three different stages of support for `async` and
`await`. Additionally, it disallows the following at parser level:
- The '@' operator in < 3.5
- Async functions in < 3.5
- Async comprehensions in < 3.6
- Underscores in numeric literals in < 3.6
- Await expression in < 3.5
- Variable annotations in < 3.6
- Async for-loops in < 3.5
- Async with-statements in < 3.5
- F-strings in < 3.6
Closeswe-like-parsers/cpython#124.
This implements full support for # type: <type> comments, # type: ignore <stuff> comments, and the func_type parsing mode for ast.parse() and compile().
Closes https://github.com/we-like-parsers/cpython/issues/95.
(For now, you need to use the master branch of mypy, since another issue unique to 3.9 had to be fixed there, and there's no mypy release yet.)
The only thing missing is `feature_version=N`, which is being tracked in https://github.com/we-like-parsers/cpython/issues/124.
After parsing is done in single statement mode, the tokenizer buffer has to be checked for additional lines and a `SyntaxError` must be raised, in case there are any.
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
An E_EOF error was only being caught after the parser exited before this commit. There are some cases though, where the tokenizer returns ERRORTOKEN *and* has set an E_EOF error (like when EOF directly follows a line continuation character) which weren't correctly handled before.
This commit also allows to pass flags to the new parser in all interfaces and fixes a bug in the parser generator that was causing to inline rules with actions, making them disappear.
When there is a SyntaxError after reading the last input character from
the tokenizer and if no newline follows it, the error message used to be
`unexpected EOF while parsing`, which is wrong.
Rename _PyInterpreterState_GET_UNSAFE() to _PyInterpreterState_GET()
for consistency with _PyThreadState_GET() and to have a shorter name
(help to fit into 80 columns).
Add also "assert(tstate != NULL);" to the function.
Fix a leak and subsequent crash in parsetok.c caused by realloc misuse on a rare codepath.
Realloc returns a null pointer on failure, and then growable_comment_array_deallocate crashes later when it dereferences it.
* Re-add removed classes Suite, slice, Param, AugLoad and AugStore.
* Add docstrings for dummy classes.
* Add docstrings for attribute aliases.
* Set __module__ to "ast" instead of "_ast".
* Remove the slice type.
* Make Slice a kind of the expr type instead of the slice type.
* Replace ExtSlice(slices) with Tuple(slices, Load()).
* Replace Index(value) with a value itself.
All non-terminal nodes in AST for expressions are now of the expr type.
The Py_FatalError() function is replaced with a macro which logs
automatically the name of the current function, unless the
Py_LIMITED_API macro is defined.
Changes:
* Add _Py_FatalErrorFunc() function.
* Remove the function name from the message of Py_FatalError() calls
which included the function name.
* Update tests.
The AST "Suite" node is no longer used and it can be removed from the ASDL definition and related structures (compiler, visitors, ...).
Co-Authored-By: Victor Stinner <vstinner@python.org>
Co-authored-by: Brett Cannon <54418+brettcannon@users.noreply.github.com>
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
The function PyTokenizer_FromUTF8 from Parser/tokenizer.c had a comment:
/* XXX: constify members. */
This patch addresses that.
In the tok_state struct:
* end and start were non-const but could be made const
* str and input were const but should have been non-const
Changes to support this include:
* decode_str() now returns a char * since it is allocated.
* PyTokenizer_FromString() and PyTokenizer_FromUTF8() each creates a
new char * for an allocate string instead of reusing the input
const char *.
* PyTokenizer_Get() and tok_get() now take const char ** arguments.
* Various local vars are const or non-const accordingly.
I was able to remove five casts that cast away constness.
Summary: This mostly migrates Python-ast.c to PEP384 and removes all statics from the whole file. This modifies the generator itself that generates the Python-ast.c. It leaves in the usage of _PyObject_LookupAttr even though it's not fully PEP384 compatible (this could always be shimmed in by anyone who needs it).
This is the converse of GH-15353 -- in addition to plenty of
scripts in the tree that are marked with the executable bit
(and so can be directly executed), there are a few that have
a leading `#!` which could let them be executed, but it doesn't
do anything because they don't have the executable bit set.
Here's a command which finds such files and marks them. The
first line finds files in the tree with a `#!` line *anywhere*;
the next-to-last step checks that the *first* line is actually of
that form. In between we filter out files that already have the
bit set, and some files that are meant as fragments to be
consumed by one or another kind of preprocessor.
$ git grep -l '^#!' \
| grep -vxFf <( \
git ls-files --stage \
| perl -lane 'print $F[3] if (!/^100644/)' \
) \
| grep -ve '\.in$' -e '^Doc/includes/' \
| while read f; do
head -c2 "$f" | grep -qxF '#!' \
&& chmod a+x "$f"; \
done
* Refactor Parser/pgen and add documentation and explanations
To improve the readability and maintainability of the parser
generator perform the following transformations:
* Separate the metagrammar parser in its own class to simplify
the parser generator logic.
* Create separate classes for DFAs and NFAs and move methods that
act exclusively on them from the parser generator to these
classes.
* Add docstrings and comment documenting the process to go from
the grammar file into NFAs and then DFAs. Detail some of the
algorithms and give some background explanations of some concepts
that will helps readers not familiar with the parser generation
process.
* Select more descriptive names for some variables and variables.
* PEP8 formatting and quote-style homogenization.
The output of the parser generator remains the same (Include/graminit.h
and Python/graminit.c remain untouched by running the new parser generator).
Batuhan Taskaya
Pablo Galindo
Victor Stinner
Benjamin Peterson
Eric V. Smith
Lysandros Nikolaou
Guido van Rossum
Shantanu
Ammar Askar
Rémi Lapeyre
Batuhan Taskaya
Serhiy Storchaka
Joannah Nanjekye
Alexander Riccio
Batuhan Taşkaya
xatier
Andy Lester
Brandt Bucher
Emmanuel Arias
Alex Henrie
Steve Dower
Vinay Sajip
Max Bernstein
Dong-hee Na
Eddie Elizondo
Zackery Spytz
Dino Viehland
Greg Price
Shashi Ranjan
Hansraj Das
Anthony Sottile