Commit Graph

729 Commits

Author SHA1 Message Date
Serhiy Storchaka 8c579b1cc8
bpo-32856: Optimize the assignment idiom in comprehensions. (GH-16814)
Now `for y in [expr]` in comprehensions is as fast as a simple
assignment `y = expr`.
2020-02-12 12:18:59 +02:00
Victor Stinner a102ed7d2f
bpo-39573: Use Py_TYPE() macro in Python and Include directories (GH-18391)
Replace direct access to PyObject.ob_type with Py_TYPE().
2020-02-07 02:24:48 +01:00
Mark Shannon 8a4cd700a7
bpo-39320: Handle unpacking of **values in compiler (GH-18141)
* Add DICT_UPDATE and DICT_MERGE bytecodes. Use them for ** unpacking.

* Remove BUILD_MAP_UNPACK and BUILD_MAP_UNPACK_WITH_CALL, as they are now unused.

* Update magic number for ** unpacking opcodes.

* Update dis.rst to incorporate new bytecodes.

* Add blurb entry.
2020-01-27 09:57:45 +00:00
Mark Shannon 13bc13960c
bpo-39320: Handle unpacking of *values in compiler (GH-17984)
* Add three new bytecodes: LIST_TO_TUPLE, LIST_EXTEND, SET_UPDATE. Use them to implement star unpacking expressions.

* Remove four bytecodes BUILD_LIST_UNPACK, BUILD_TUPLE_UNPACK, BUILD_SET_UNPACK and  BUILD_TUPLE_UNPACK_WITH_CALL opcodes as they are now unused.

* Update magic number and dis.rst for new bytecodes.
2020-01-23 09:25:17 +00:00
Ammar Askar e92d39303f Fix compiler warning on Windows (GH-18012)
Python-ast.h contains a macro named Yield that conflicts with the Yield macro
in Windows system headers. While Python-ast.h has an "undef Yield" directive
to prevent this, it means that Python-ast.h must be included before Windows
header files or we run into a re-declaration warning. In commit c96be811fa
an include for pycore_pystate.h was added which indirectly includes Windows
header files. In this commit we re-order the includes to fix this warning.
2020-01-15 10:48:40 -06:00
Mark Shannon 9af0e47b17
bpo-39156: Break up COMPARE_OP into four logically distinct opcodes. (GH-17754)
Break up COMPARE_OP into four logically distinct opcodes:
* COMPARE_OP for rich comparisons
* IS_OP for 'is' and 'is not' tests
* CONTAINS_OP for 'in' and 'is not' tests
* JUMP_IF_NOT_EXC_MATCH for checking exceptions in 'try-except' statements.
2020-01-14 10:12:45 +00:00
Mark Shannon 88dce26da6
Fix handling of line numbers around finally-blocks. (#17737) 2019-12-30 09:53:36 +00:00
Brandt Bucher 6dd9b64770 bpo-38328: Speed up the creation time of constant list and set display. (GH-17114) 2019-11-26 15:16:53 +09:00
Mark Shannon fee552669f
Produce cleaner bytecode for 'with' and 'async with' by generating separate code for normal and exceptional paths. (#6641)
Remove BEGIN_FINALLY, END_FINALLY, CALL_FINALLY and POP_FINALLY bytecodes. Implement finally blocks by code duplication.
Reimplement frame.lineno setter using line numbers rather than bytecode offsets.
2019-11-21 09:11:43 +00:00
Pablo Galindo 6c3e66a34b
bpo-38640: Allow break and continue in always false while loops (GH-16992) 2019-10-30 11:53:26 +00:00
Hansraj Das 01171ebd96 Typo fix: "empy" should be "empty". (GH-16666) 2019-10-08 19:24:02 -07:00
T. Wouters 99b54d6817 Revert "Fix depth-first-search computation in compile.c (GH-16042)" (GH-16050)
This reverts commit 355f3e1e5c.

bpo-38135
2019-09-12 15:05:33 +01:00
Mark Shannon 355f3e1e5c Fix depth-first-search computation in compile.c (GH-16042) 2019-09-12 06:42:23 -07:00
Zackery Spytz ce6a070414 bpo-34880: Add the LOAD_ASSERTION_ERROR opcode. (GH-15073)
Fix assert statement misbehavior if AssertionError is shadowed.
2019-08-25 12:44:09 +03:00
Serhiy Storchaka ef61c524dd
bpo-37830: Fix compilation of break and continue in finally. (GH-15320)
Fix compilation of "break" and "continue" in the
"finally" block when the corresponding "try" block
contains "return" with a non-constant value.
2019-08-24 13:11:52 +03:00
Min ho Kim c4cacc8c5e Fix typos in comments, docs and test names (#15018)
* Fix typos in comments, docs and test names

* Update test_pyparse.py

account for change in string length

* Apply suggestion: splitable -> splittable

Co-Authored-By: Terry Jan Reedy <tjreedy@udel.edu>

* Apply suggestion: splitable -> splittable

Co-Authored-By: Terry Jan Reedy <tjreedy@udel.edu>

* Apply suggestion: Dealloccte -> Deallocate

Co-Authored-By: Terry Jan Reedy <tjreedy@udel.edu>

* Update posixmodule checksum.

* Reverse idlelib changes.
2019-07-30 18:16:13 -04:00
Pablo Galindo 18c5f9d44d bpo-37500: Make sure dead code does not generate bytecode but also detect syntax errors (GH-14612)
https://bugs.python.org/issue37500

Add a new field to the compiler structure that allows to be configured
so no bytecode is emitted. In this way is possible to detect errors by
walking the nodes while preserving optimizations.


https://bugs.python.org/issue37500
2019-07-15 02:15:01 -07:00
Pablo Galindo 4a2edc34a4 bpo-37221: Add PyCode_NewWithPosOnlyArgs to be used internally and set PyCode_New as a compatibility wrapper (GH-13959)
Add PyCode_NewEx to be used internally and set PyCode_New as a compatibility wrapper
2019-07-01 12:35:05 +02:00
Jörn Heissler c8a35417db bpo-35224: Reverse evaluation order of key: value in dict comprehensions (GH-14139)
… as proposed in PEP 572; key is now evaluated before value.





https://bugs.python.org/issue35224
2019-06-22 07:40:55 -07:00
Victor Stinner 37d66d7d4b
bpo-37253: Add _PyCompilerFlags_INIT macro (GH-14018)
Add a new _PyCompilerFlags_INIT macro to initialize PyCompilerFlags
variables, rather than initializing cf_flags and cf_feature_version
explicitly in each variable.
2019-06-13 02:16:41 +02:00
Pablo Galindo cd74e66a8c
bpo-37122: Make co->co_argcount represent the total number of positonal arguments in the code object (GH-13726) 2019-06-01 18:08:04 +01:00
Pablo Galindo a0c01bf136
bpo-37115: Support annotations in positional-only arguments (GH-13698) 2019-05-31 15:19:50 +01:00
Eric V. Smith 6f6ff8a565
bpo-37050: Remove expr_text from FormattedValue ast node, use Constant node instead (GH-13597)
When using the "=" debug functionality of f-strings, use another Constant node (or a merged constant node) instead of adding expr_text to the FormattedValue node.
2019-05-27 15:31:52 -04:00
Victor Stinner 331a6a56e9
bpo-36763: Implement the PEP 587 (GH-13592)
* Add a whole new documentation page:
  "Python Initialization Configuration"
* PyWideStringList_Append() return type is now PyStatus,
  instead of int
* PyInterpreterState_New() now calls PyConfig_Clear() if
  PyConfig_InitPythonConfig() fails.
* Rename files:

  * Python/coreconfig.c => Python/initconfig.c
  * Include/cpython/coreconfig.h => Include/cpython/initconfig.h
  * Include/internal/: pycore_coreconfig.h => pycore_initconfig.h

* Rename structures

  * _PyCoreConfig => PyConfig
  * _PyPreConfig => PyPreConfig
  * _PyInitError => PyStatus
  * _PyWstrList => PyWideStringList

* Rename PyConfig fields:

  * use_module_search_paths => module_search_paths_set
  * module_search_path_env => pythonpath_env

* Rename PyStatus field: _func => func
* PyInterpreterState: rename core_config field to config
* Rename macros and functions:

  * _PyCoreConfig_SetArgv() => PyConfig_SetBytesArgv()
  * _PyCoreConfig_SetWideArgv() => PyConfig_SetArgv()
  * _PyCoreConfig_DecodeLocale() => PyConfig_SetBytesString()
  * _PyInitError_Failed() => PyStatus_Exception()
  * _Py_INIT_ERROR_TYPE_xxx enums => _PyStatus_TYPE_xxx
  * _Py_UnixMain() => Py_BytesMain()
  * _Py_ExitInitError() => Py_ExitStatusException()
  * _Py_PreInitializeFromArgs() => Py_PreInitializeFromBytesArgs()
  * _Py_PreInitializeFromWideArgs() => Py_PreInitializeFromArgs()
  * _Py_PreInitialize() => Py_PreInitialize()
  * _Py_RunMain() => Py_RunMain()
  * _Py_InitializeFromConfig() => Py_InitializeFromConfig()
  * _Py_INIT_XXX() => _PyStatus_XXX()
  * _Py_INIT_FAILED() => _PyStatus_EXCEPTION()

* Rename 'err' PyStatus variables to 'status'
* Convert RUN_CODE() macro to config_run_code() static inline function
* Remove functions:

  * _Py_InitializeFromArgs()
  * _Py_InitializeFromWideArgs()
  * _PyInterpreterState_GetCoreConfig()
2019-05-27 16:39:22 +02:00
Matthias Bussonnier 565b4f1ac7 bpo-34616: Add PyCF_ALLOW_TOP_LEVEL_AWAIT to allow top-level await (GH-13148)
Co-Authored-By: Yury Selivanov <yury@magic.io>
2019-05-21 16:12:02 -04:00
Chris Angelico ad098b6750 Annotate the unexplained assignment in exception unbinding (GH-11448) 2019-05-21 09:34:19 -04:00
David Carlier 27ee0f8551 Fix couple of dead code paths (GH-7418) 2019-05-17 19:46:22 -04:00
Pablo Galindo af8646c805
bpo-1875: Raise SyntaxError in invalid blocks that will be optimised away (GH-13332)
Move the check for dead conditionals (if 0) to the peephole optimizer
and make sure that the code block is still compiled to report any
existing syntax errors within.
2019-05-17 11:37:08 +01:00
Victor Stinner c96be811fa
bpo-36900: Replace global conf vars with config (GH-13299)
Replace global configuration variables with core_config read from the
current interpreter.

Cleanup dynload_hpux.c.
2019-05-14 17:34:56 +02:00
Eric V. Smith 9a4135e939
bpo-36817: Add f-string debugging using '='. (GH-13123)
If a "=" is specified a the end of an f-string expression, the f-string will evaluate to the text of the expression, followed by '=', followed by the repr of the value of the expression.
2019-05-08 16:28:48 -04:00
Pablo Galindo 8c77b8cb91
bpo-36540: PEP 570 -- Implementation (GH-12701)
This commit contains the implementation of PEP570: Python positional-only parameters.

* Update Grammar/Grammar with new typedarglist and varargslist

* Regenerate grammar files

* Update and regenerate AST related files

* Update code object

* Update marshal.c

* Update compiler and symtable

* Regenerate importlib files

* Update callable objects

* Implement positional-only args logic in ceval.c

* Regenerate frozen data

* Update standard library to account for positional-only args

* Add test file for positional-only args

* Update other test files to account for positional-only args

* Add News entry

* Update inspect module and related tests
2019-04-29 13:36:57 +01:00
Simeon 63b5fc5f42 Fix typos in compile.c comments (GH-12752) 2019-04-09 16:36:57 -07:00
Zackery Spytz 97f5de01ad bpo-35284: Fix the error handling in the compiler's compiler_call(). (GH-10625)
compiler_call() needs to check if an error occurred during the
maybe_optimize_method_call() call.
2019-03-22 09:30:32 +02:00
Zackery Spytz 9b4a1b1e23 bpo-36374: Fix a possible null pointer dereference (GH-12449)
https://bugs.python.org/issue36374
2019-03-20 02:16:25 -07:00
Guido van Rossum 495da29225 bpo-35975: Support parsing earlier minor versions of Python 3 (GH-12086)
This adds a `feature_version` flag to `ast.parse()` (documented) and `compile()` (hidden) that allow tweaking the parser to support older versions of the grammar. In particular if `feature_version` is 5 or 6, the hacks for the `async` and `await` keyword from PEP 492 are reinstated. (For 7 or higher, these are unconditionally treated as keywords, but they are still special tokens rather than `NAME` tokens that the parser driver recognizes.)



https://bugs.python.org/issue35975
2019-03-07 12:38:08 -08:00
Serhiy Storchaka d8b3a98c90
bpo-36187: Remove NamedStore. (GH-12167)
NamedStore has been replaced with Store. The difference between
NamedStore and Store is handled when precess the NamedExpr node
one level upper.
2019-03-05 20:42:06 +02:00
Serhiy Storchaka 4583525835
bpo-35798: Fix duplicate SyntaxWarning: "is" with a literal. (GH-11639) 2019-02-16 08:29:46 +02:00
Serhiy Storchaka 62e4481238
bpo-15248: Emit a compiler warning when missed a comma before tuple or list. (GH-11757) 2019-02-16 08:12:19 +02:00
Emily Morehouse 8f59ee01be
bpo-35224: PEP 572 Implementation (#10497)
* Add tokenization of :=
- Add token to Include/token.h. Add token to documentation in Doc/library/token.rst.
- Run `./python Lib/token.py` to regenerate Lib/token.py.
- Update Parser/tokenizer.c: add case to handle `:=`.

* Add initial usage of := in grammar.

* Update Python.asdl to match the grammar updates. Regenerated Include/Python-ast.h and Python/Python-ast.c

* Update AST and compiler files in Python/ast.c and Python/compile.c. Basic functionality, this isn't scoped properly

* Regenerate Lib/symbol.py using `./python Lib/symbol.py`

* Tests - Fix failing tests in test_parser.py due to changes in token numbers for internal representation

* Tests - Add simple test for := token

* Tests - Add simple tests for named expressions using expr and suite

* Tests - Update number of levels for nested expressions to prevent stack overflow

* Update symbol table to handle NamedExpr

* Update Grammar to allow assignment expressions in if statements.
Regenerate Python/graminit.c accordingly using `make regen-grammar`

* Tests - Add additional tests for named expressions in RoundtripLegalSyntaxTestCase, based on examples and information directly from PEP 572

Note: failing tests are currently commented out (4 out of 24 tests currently fail)

* Tests - Add temporary syntax test failure tests in test_parser.py

Note: There is an outstanding TODO for this -- syntax tests need to be
moved to a different file (presumably test_syntax.py), but this is
covering what needs to be tested at the moment, and it's more convenient
to run a single test for the time being

* Add support for allowing assignment expressions as function argument annotations. Uncomment tests for these cases because they all pass now!

* Tests - Move existing syntax tests out of test_parser.py and into test_named_expressions.py. Refactor syntax tests to use unittest

* Add TargetScopeError exception to extend SyntaxError

Note: This simply creates the TargetScopeError exception, it is not yet
used anywhere

* Tests - Update tests per PEP 572

Continue refactoring test suite:
The named expression test suite now checks for any invalid cases that
throw exceptions (no longer limited to SyntaxErrors), assignment tests
to ensure that variables are properly assigned, and scope tests to
ensure that variable availability and values are correct

Note:
- There are still tests that are marked to skip, as they are not yet
implemented
- There are approximately 300 lines of the PEP that have not yet been
addressed, though these may be deferred

* Documentation - Small updates to XXX/todo comments

- Remove XXX from child description in ast.c
- Add comment with number of previously supported nested expressions for
3.7.X in test_parser.py

* Fix assert in seq_for_testlist()

* Cleanup - Denote "Not implemented -- No keyword args" on failing test case. Fix PEP8 error for blank lines at beginning of test classes in test_parser.py

* Tests - Wrap all file opens in `with...as` to ensure files are closed

* WIP: handle f(a := 1)

* Tests and Cleanup - No longer skips keyword arg test. Keyword arg test now uses a simpler test case and does not rely on an external file. Remove print statements from ast.c

* Tests - Refactor last remaining test case that relied on on external file to use a simpler test case without the dependency

* Tests - Add better description of remaning skipped tests. Add test checking scope when using assignment expression in a function argument

* Tests - Add test for nested comprehension, testing value and scope. Fix variable name in skipped comprehension scope test

* Handle restriction of LHS for named expressions - can only assign to LHS of type NAME. Specifically, restrict assignment to tuples

This adds an alternative set_context specifically for named expressions,
set_namedexpr_context. Thus, context is now set differently for standard
assignment versus assignment for named expressions in order to handle
restrictions.

* Tests - Update negative test case for assigning to lambda to match new error message. Add negative test case for assigning to tuple

* Tests - Reorder test cases to group invalid syntax cases and named assignment target errors

* Tests - Update test case for named expression in function argument - check that result and variable are set correctly

* Todo - Add todo for TargetScopeError based on Guido's comment (2b3acd37bd (r30472562))

* Tests - Add named expression tests for assignment operator in function arguments

Note: One of two tests are skipped, as function arguments are currently treating
an assignment expression inside of parenthesis as one child, which does
not properly catch the named expression, nor does it count arguments
properly

* Add NamedStore to expr_context. Regenerate related code with `make regen-ast`

* Add usage of NamedStore to ast_for_named_expr in ast.c. Update occurances of checking for Store to also handle NamedStore where appropriate

* Add ste_comprehension to _symtable_entry to track if the namespace is a comprehension. Initialize ste_comprehension to 0. Set set_comprehension to 1 in symtable_handle_comprehension

* s/symtable_add_def/symtable_add_def_helper. Add symtable_add_def to handle grabbing st->st_cur and passing it to symtable_add_def_helper. This now allows us to call the original code from symtable_add_def by instead calling symtable_add_def_helper with a different ste.

* Refactor symtable_record_directive to take lineno and col_offset as arguments instead of stmt_ty. This allows symtable_record_directive to be used for stmt_ty and expr_ty

* Handle elevating scope for named expressions in comprehensions.

* Handle error for usage of named expression inside a class block

* Tests - No longer skip scope tests. Add additional scope tests

* Cleanup - Update error message for named expression within a comprehension within a class. Update comments. Add assert for symtable_extend_namedexpr_scope to validate that we always find at least a ModuleScope if we don't find a Class or FunctionScope

* Cleanup - Add missing case for NamedStore in expr_context_name. Remove unused var in set_namedexpr_content

* Refactor - Consolidate set_context and set_namedexpr_context to reduce duplicated code. Special cases for named expressions are handled by checking if ctx is NamedStore

* Cleanup - Add additional use cases for ast_for_namedexpr in usage comment. Fix multiple blank lines in test_named_expressions

* Tests - Remove unnecessary test case. Renumber test case function names

* Remove TargetScopeError for now. Will add back if needed

* Cleanup - Small comment nit for consistency

* Handle positional argument check with named expression

* Add TargetScopeError exception definition. Add documentation for TargetScopeError in c-api docs. Throw TargetScopeError instead of SyntaxError when using a named expression in a comprehension within a class scope

* Increase stack size for parser by 200. This is a minimal change (approx. 5kb) and should not have an impact on any systems. Update parser test to allow 99 nested levels again

* Add TargetScopeError to exception_hierarchy.txt for test_baseexception.py_

* Tests - Major update for named expression tests, both in test_named_expressions and test_parser

- Add test for TargetScopeError
- Add tests for named expressions in comprehension scope and edge cases
- Add tests for named expressions in function arguments (declarations
and call sites)
- Reorganize tests to group them more logically

* Cleanup - Remove unnecessary comment

* Cleanup - Comment nitpicks

* Explicitly disallow assignment expressions to a name inside parentheses, e.g.: ((x) := 0)

- Add check for LHS types to detect a parenthesis then a name (see note)
- Add test for this scenario
- Update tests for changed error message for named assignment to a tuple
(also, see note)

Note: This caused issues with the previous error handling for named assignment
to a LHS that contained an expression, such as a tuple. Thus, the check
for the LHS of a named expression must be changed to be more specific if
we wish to maintain the previous error messages

* Cleanup - Wrap lines more strictly in test file

* Revert "Explicitly disallow assignment expressions to a name inside parentheses, e.g.: ((x) := 0)"

This reverts commit f1531400ca7d7a2d148830c8ac703f041740896d.

* Add NEWS.d entry

* Tests - Fix error in test_pickle.test_exceptions by adding TargetScopeError to list of exceptions

* Tests - Update error message tests to reflect improved messaging convention (s/can't/cannot)

* Remove cases that cannot be reached in compile.c. Small linting update.

* Update Grammar/Tokens to add COLONEQUAL. Regenerate all files

* Update TargetScopeError PRE_INIT and POST_INIT, as this was purposefully left out when fixing rebase conflicts

* Add NamedStore back and regenerate files

* Pass along line number and end col info for named expression

* Simplify News entry

* Fix compiler warning and explicity mark fallthrough
2019-01-24 16:49:56 -07:00
Ivan Levkivskyi 9932a22897
bpo-33416: Add end positions to Python AST (GH-11605)
The majority of this PR is tediously passing `end_lineno` and `end_col_offset` everywhere. Here are non-trivial points:
* It is not possible to reconstruct end positions in AST "on the fly", some information is lost after an AST node is constructed, so we need two more attributes for every AST node `end_lineno` and `end_col_offset`.
* I add end position information to both CST and AST.  Although it may be technically possible to avoid adding end positions to CST, the code becomes more cumbersome and less efficient.
* Since the end position is not known for non-leaf CST nodes while the next token is added, this requires a bit of extra care (see `_PyNode_FinalizeEndPos`). Unless I made some mistake, the algorithm should be linear.
* For statements, I "trim" the end position of suites to not include the terminal newlines and dedent (this seems to be what people would expect), for example in
  ```python
  class C:
      pass

  pass
  ```
  the end line and end column for the class definition is (2, 8).
* For `end_col_offset` I use the common Python convention for indexing, for example for `pass` the `end_col_offset` is 4 (not 3), so that `[0:4]` gives one the source code that corresponds to the node.
* I added a helper function `ast.get_source_segment()`, to get source text segment corresponding to a given AST node. It is also useful for testing.

An (inevitable) downside of this PR is that AST now takes almost 25% more memory. I think however it is probably justified by the benefits.
2019-01-22 11:18:22 +00:00
Serhiy Storchaka 3bcbedc9f1
bpo-34850: Emit a warning for "is" and "is not" with a literal. (GH-9642) 2019-01-18 07:47:48 +02:00
INADA Naoki f7e4d3642f bpo-34100: compile: Re-enable frozenset merging (GH-10760)
This reverts commit 1005c84535.
2018-11-28 16:58:46 +01:00
Victor Stinner 1005c84535
bpo-34100: Partially revert merge_consts_recursive() (GH-10743)
Partically revert commit c2e1607a51 to
fix a reference leak.
2018-11-27 15:12:47 +01:00
INADA Naoki c2e1607a51 bpo-34100: Merge constants recursively (GH-8341)
There are some same consts in a module.  This commit merges them into
single instance.  It reduces number of objects in memory after loading modules.


https://bugs.python.org/issue34100
2018-11-26 04:23:22 -08:00
Victor Stinner 5f2df88b63
bpo-35177: Add dependencies between header files (GH-10361)
* ast.h now includes Python-ast.h and node.h
* parsetok.h now includes node.h and grammar.h
* symtable.h now includes Python-ast.h
* Modify asdl_c.py to enhance Python-ast.h:

  * Add #ifndef/#define Py_PYTHON_AST_H to be able to include the header
    twice
  * Add "extern { ... }" for C++
  * Undefine "Yield" macro conflicting with winbase.h

* Remove "#undef Yield" from C files, it's now done in Python-ast.h
* Remove now useless includes in C files
2018-11-12 00:56:19 +01:00
Serhiy Storchaka 95b6acf951
bpo-34876: Change the lineno of the AST for decorated function and class. (GH-9731)
It was overridden by the lineno of the first decorator. Now it is
the lineno of 'def' or 'class'.
2018-10-30 13:16:02 +02:00
Serhiy Storchaka d31e7730cd
bpo-35029: Replace the SyntaxWarning exception with a SyntaxError. (GH-9999)
If SyntaxWarning was raised as an exception, it will be replaced
with a SyntaxError for better error reporting.
2018-10-21 10:09:39 +03:00
Zackery Spytz 53ebf4b070 Fix an incorrect check in compiler_try_except(). (GH-9810) 2018-10-12 08:54:03 +03:00
Serhiy Storchaka 3f22811fef
bpo-32892: Use ast.Constant instead of specific constant AST types. (GH-9445) 2018-09-27 17:42:37 +03:00
Ammar Askar 025eb98dc0 bpo-34683: Make SyntaxError column offsets consistently 1-indexed (gh-9338)
Also point to start of tokens in parsing errors.

Fixes bpo-34683
2018-09-24 14:12:49 -07:00