bpo-29137: Remove fpectl module (#4789)
This module has never been enabled by default, never worked correctly
on x86-64, and caused ABI problems that caused C extension
compatibility. See bpo-29137 for details/discussion.
diff --git a/Include/pyfpe.h b/Include/pyfpe.h
index d86cb74..5a99e39 100644
--- a/Include/pyfpe.h
+++ b/Include/pyfpe.h
@@ -1,176 +1,12 @@
#ifndef Py_PYFPE_H
#define Py_PYFPE_H
-#ifdef __cplusplus
-extern "C" {
-#endif
-/*
- ---------------------------------------------------------------------
- / Copyright (c) 1996. \
- | The Regents of the University of California. |
- | All rights reserved. |
- | |
- | Permission to use, copy, modify, and distribute this software for |
- | any purpose without fee is hereby granted, provided that this en- |
- | tire notice is included in all copies of any software which is or |
- | includes a copy or modification of this software and in all |
- | copies of the supporting documentation for such software. |
- | |
- | This work was produced at the University of California, Lawrence |
- | Livermore National Laboratory under contract no. W-7405-ENG-48 |
- | between the U.S. Department of Energy and The Regents of the |
- | University of California for the operation of UC LLNL. |
- | |
- | DISCLAIMER |
- | |
- | This software was prepared as an account of work sponsored by an |
- | agency of the United States Government. Neither the United States |
- | Government nor the University of California nor any of their em- |
- | ployees, makes any warranty, express or implied, or assumes any |
- | liability or responsibility for the accuracy, completeness, or |
- | usefulness of any information, apparatus, product, or process |
- | disclosed, or represents that its use would not infringe |
- | privately-owned rights. Reference herein to any specific commer- |
- | cial products, process, or service by trade name, trademark, |
- | manufacturer, or otherwise, does not necessarily constitute or |
- | imply its endorsement, recommendation, or favoring by the United |
- | States Government or the University of California. The views and |
- | opinions of authors expressed herein do not necessarily state or |
- | reflect those of the United States Government or the University |
- | of California, and shall not be used for advertising or product |
- \ endorsement purposes. /
- ---------------------------------------------------------------------
-*/
-/*
- * Define macros for handling SIGFPE.
- * Lee Busby, LLNL, November, 1996
- * busby1@llnl.gov
- *
- *********************************************
- * Overview of the system for handling SIGFPE:
- *
- * This file (Include/pyfpe.h) defines a couple of "wrapper" macros for
- * insertion into your Python C code of choice. Their proper use is
- * discussed below. The file Python/pyfpe.c defines a pair of global
- * variables PyFPE_jbuf and PyFPE_counter which are used by the signal
- * handler for SIGFPE to decide if a particular exception was protected
- * by the macros. The signal handler itself, and code for enabling the
- * generation of SIGFPE in the first place, is in a (new) Python module
- * named fpectl. This module is standard in every respect. It can be loaded
- * either statically or dynamically as you choose, and like any other
- * Python module, has no effect until you import it.
- *
- * In the general case, there are three steps toward handling SIGFPE in any
- * Python code:
- *
- * 1) Add the *_PROTECT macros to your C code as required to protect
- * dangerous floating point sections.
- *
- * 2) Turn on the inclusion of the code by adding the ``--with-fpectl''
- * flag at the time you run configure. If the fpectl or other modules
- * which use the *_PROTECT macros are to be dynamically loaded, be
- * sure they are compiled with WANT_SIGFPE_HANDLER defined.
- *
- * 3) When python is built and running, import fpectl, and execute
- * fpectl.turnon_sigfpe(). This sets up the signal handler and enables
- * generation of SIGFPE whenever an exception occurs. From this point
- * on, any properly trapped SIGFPE should result in the Python
- * FloatingPointError exception.
- *
- * Step 1 has been done already for the Python kernel code, and should be
- * done soon for the NumPy array package. Step 2 is usually done once at
- * python install time. Python's behavior with respect to SIGFPE is not
- * changed unless you also do step 3. Thus you can control this new
- * facility at compile time, or run time, or both.
- *
- ********************************
- * Using the macros in your code:
- *
- * static PyObject *foobar(PyObject *self,PyObject *args)
- * {
- * ....
- * PyFPE_START_PROTECT("Error in foobar", return 0)
- * result = dangerous_op(somearg1, somearg2, ...);
- * PyFPE_END_PROTECT(result)
- * ....
- * }
- *
- * If a floating point error occurs in dangerous_op, foobar returns 0 (NULL),
- * after setting the associated value of the FloatingPointError exception to
- * "Error in foobar". ``Dangerous_op'' can be a single operation, or a block
- * of code, function calls, or any combination, so long as no alternate
- * return is possible before the PyFPE_END_PROTECT macro is reached.
- *
- * The macros can only be used in a function context where an error return
- * can be recognized as signaling a Python exception. (Generally, most
- * functions that return a PyObject * will qualify.)
- *
- * Guido's original design suggestion for PyFPE_START_PROTECT and
- * PyFPE_END_PROTECT had them open and close a local block, with a locally
- * defined jmp_buf and jmp_buf pointer. This would allow recursive nesting
- * of the macros. The Ansi C standard makes it clear that such local
- * variables need to be declared with the "volatile" type qualifier to keep
- * setjmp from corrupting their values. Some current implementations seem
- * to be more restrictive. For example, the HPUX man page for setjmp says
- *
- * Upon the return from a setjmp() call caused by a longjmp(), the
- * values of any non-static local variables belonging to the routine
- * from which setjmp() was called are undefined. Code which depends on
- * such values is not guaranteed to be portable.
- *
- * I therefore decided on a more limited form of nesting, using a counter
- * variable (PyFPE_counter) to keep track of any recursion. If an exception
- * occurs in an ``inner'' pair of macros, the return will apparently
- * come from the outermost level.
- *
+/* These macros used to do something when Python was built with --with-fpectl,
+ * but support for that was dropped in 3.7. We continue to define them though,
+ * to avoid breaking API users.
*/
-#ifdef WANT_SIGFPE_HANDLER
-#include <signal.h>
-#include <setjmp.h>
-#include <math.h>
-extern jmp_buf PyFPE_jbuf;
-extern int PyFPE_counter;
-extern double PyFPE_dummy(void *);
-
-#define PyFPE_START_PROTECT(err_string, leave_stmt) \
-if (!PyFPE_counter++ && setjmp(PyFPE_jbuf)) { \
- PyErr_SetString(PyExc_FloatingPointError, err_string); \
- PyFPE_counter = 0; \
- leave_stmt; \
-}
-
-/*
- * This (following) is a heck of a way to decrement a counter. However,
- * unless the macro argument is provided, code optimizers will sometimes move
- * this statement so that it gets executed *before* the unsafe expression
- * which we're trying to protect. That pretty well messes things up,
- * of course.
- *
- * If the expression(s) you're trying to protect don't happen to return a
- * value, you will need to manufacture a dummy result just to preserve the
- * correct ordering of statements. Note that the macro passes the address
- * of its argument (so you need to give it something which is addressable).
- * If your expression returns multiple results, pass the last such result
- * to PyFPE_END_PROTECT.
- *
- * Note that PyFPE_dummy returns a double, which is cast to int.
- * This seeming insanity is to tickle the Floating Point Unit (FPU).
- * If an exception has occurred in a preceding floating point operation,
- * some architectures (notably Intel 80x86) will not deliver the interrupt
- * until the *next* floating point operation. This is painful if you've
- * already decremented PyFPE_counter.
- */
-#define PyFPE_END_PROTECT(v) PyFPE_counter -= (int)PyFPE_dummy(&(v));
-
-#else
-
#define PyFPE_START_PROTECT(err_string, leave_stmt)
#define PyFPE_END_PROTECT(v)
-#endif
-
-#ifdef __cplusplus
-}
-#endif
#endif /* !Py_PYFPE_H */