The string comparison was reporting '11' < '4' (so OpenMP tests were being skipped on GCC 11)

Attribute names used to be fully qualified like "_cython_3_0_0a9.cython_function_or_method" instead of the plain name.

Closes https://github.com/cython/cython/issues/4373

This can happen (rarely) with exceptions that occur very early in the module init process.

Fixes https://github.com/cython/cython/issues/4377

Uses a fake Numpy module for testing to make a version of "import_array" that always fails.

This is explicitly tested for: https://github.com/cython/cython/blob/aea4e6b84b38223c540266f8c57093ee2039f284/tests/run/test_coroutines_pep492.pyx#L2400

It turns out some earlier versions of Python assume that
C-API classes without a dict or slot are pickleable by the class
name. Currently it isn't pickleable because the class name lookup
is failing but this change makes it more robust.

See https://github.com/cython/cython/pull/4376

Among other things this makes it pickleable by ensuring that it's the same object each time.

"PyUnicode_CompareWithASCIIString()" does not raise exceptions and takes a "const char*" as argument.

ff16389c introduced convenient functions get_value() and get_value_no_default().

Unfortunately, the variable `value` in these functions was not set before usage with PyContextVar_Get().
This triggered some warnings:

Error compiling Cython file:
------------------------------------------------------------
...
    """Return a new reference to the value of the context variable,
    or the default value of the context variable,
    or None if no such value or default was found.
    """
    cdef PyObject *value
    PyContextVar_Get(var, NULL, &value)
                                ^
------------------------------------------------------------

Cython/Includes/cpython/contextvars.pxd:118:33: local variable 'value' might be referenced before assignment

Error compiling Cython file:
------------------------------------------------------------
...
    or the provided default value if no such value was found.

    Ignores the default value of the context variable, if any.
    """
    cdef PyObject *value
    PyContextVar_Get(var, <PyObject*>default_value, &value)
                                                    ^
------------------------------------------------------------

Cython/Includes/cpython/contextvars.pxd:136:53: local variable 'value' might be referenced before assignment

It can be replicated by simply importing `cpython`:
echo "cimport cpython" >/tmp/mod.pyx && ./cython.py -Werror -Wextra /tmp/mod.pyx

The solution is simply to assign NULL to `value` on declaration.

See
https://github.com/cython/cython/pull/4349
https://github.com/cython/cython/commit/0574dbceef7b8ee16a9cc94091c3629dfa23133d#r54025763

This was causing c++ classes in if-statements to crash.
Fixes #4348

This was causing c++ classes in if-statements to crash.
Fixes #4348

Avoid copying unaligned 16-bit values since some platforms require them to be aligned. Use memcpy() instead to let the C compiler decide how to do it.

Closes https://github.com/cython/cython/issues/4343

Avoid copying unaligned 16-bit values since some platforms require them to be aligned. Use memcpy() instead to let the C compiler decide how to do it.

Closes https://github.com/cython/cython/issues/4343

See https://github.com/cython/cython/pull/4142#issuecomment-831464115

I don't think MinGW has worked since around Python 3.4 (but I'm
not completely confident in that) while I know that MSVC does
work. Therefore we should recommend that.

Compiling ExprNodes.py was creating hundreds of tuples containing ("self", "env") for example, because it wasn't able to match and deduplicate them.

"PyUnicode_CompareWithASCIIString()" does not raise exceptions and takes a "const char*" as argument.

* Avoid usage of `const` or `volatile` in buffer struct field declarations.
* Avoid newline replacement in the test helper functions `write_file()` and `write_newer_file()`.

See https://github.com/cython/cython/pull/4324

These were lost when cdef properties (for extern types) were introduced.

Closes #4322 (based on my interpretation of the problem as an error-reporting issue)

Adds utility code sections to toggle C compiler warnings for the duration of the utility code.

Fix output encoding problems in the test runner with Py2.7 by not trying to decode the C compiler output and instead printing it unchanged as bytes.

Revert "Fix output encoding problems in the test runner with Py2.7 by replacing implicit calls to str() with (unicode) string concatenation."

This reverts commit 931710d8.

Fix output encoding problems in the test runner with Py2.7 by replacing implicit calls to str() with (unicode) string concatenation.

runtests: include the C compiler error output in the compile exception to show it at the end of the test run.

Turns out that typeid() and C++ operators already work with "cpp_locals".

Add a warning in the docs that "conditional compilation" is not a good way to do most things that users commonly do with it.

See the discussion in https://github.com/cython/cython/issues/4287

Fix compilation of "ParseTreeTransforms" in Py2. It previously tried to compare the 'directivetype' to 'str', which misses Py2 str when compiling with language level 3.

Add CI jobs that compile more Cython modules with "--cython-compile-all", to make sure that this keeps working and to allow comparing the performance difference.

Fixes https://github.com/cython/cython/issues/3174
Closes https://github.com/cython/cython/pull/3175

I've removed all identification of is_self_arg from the parser, since I think it's better dealt with when analysing the declarations.

Original test copied from https://github.com/cython/cython/pull/3175