This fixes both the traceback.py module and the C code for formatting syntax errors (in Python/pythonrun.c). They now both consistently do the following:
- Suppress caret if it points left of text
- Allow caret pointing just past end of line
- If caret points past end of line, clip to *just* past end of line
The syntax error formatting code in traceback.py was mostly rewritten; small, subtle changes were applied to the C code in pythonrun.c.
There's still a difference when the text contains embedded newlines. Neither handles these very well, and I don't think the case occurs in practice.
Automerge-Triggered-By: @gvanrossum
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.
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.
* Rename PyConfig.use_peg to _use_peg_parser
* Document PyConfig._use_peg_parser and mark it a deprecated
* Mark -X oldparser option and PYTHONOLDPARSER env var as deprecated
in the documentation.
* Add use_old_parser() and skip_if_new_parser() to test.support
* Remove sys.flags.use_peg: use_old_parser() uses
_testinternalcapi.get_configs() instead.
* Enhance test_embed tests
* subprocess._args_from_interpreter_flags() copies -X oldparser
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.
Don't access PyInterpreterState.config member directly anymore, but
use new functions:
* _PyInterpreterState_GetConfig()
* _PyInterpreterState_SetConfig()
* _Py_GetConfig()
Replace _PyInterpreterState_Get() function call with
_PyInterpreterState_GET_UNSAFE() macro which is more efficient but
don't check if tstate or interp is NULL.
_Py_GetConfigsAsDict() now uses _PyThreadState_GET().
Move the following functions from the public C API to the internal C
API:
* _PyDebug_PrintTotalRefs(),
* _Py_PrintReferenceAddresses()
* _Py_PrintReferences()
Fix sys.excepthook() and PyErr_Display() if a filename is a bytes
string. For example, for a SyntaxError exception where the filename
attribute is a bytes string.
Cleanup also test_sys:
* Sort imports.
* Rename numruns global var to INTERN_NUMRUNS.
* Add DisplayHookTest and ExceptHookTest test case classes.
* Don't save/restore sys.stdout and sys.displayhook using
setUp()/tearDown(): do it in each test method.
* Test error case (call hook with no argument) after the success case.
Add a new _PyCompilerFlags_INIT macro to initialize PyCompilerFlags
variables, rather than initializing cf_flags and cf_feature_version
explicitly in each variable.
sys.excepthook() and sys.unraisablehook() now explicitly flush the
file (usually sys.stderr).
If file.flush() fails, sys.excepthook() silently ignores the error,
whereas sys.unraisablehook() logs the new exception.
