Trac #33793: replace SAGE_TMP in SPYX_TMP.

With the move to a real temporary directory, we now also install an
atexit hook to clean up the tempdir that is created. Moreover
SPYX_TMP() is renamed to a new a @cached_function spyx_tmp() so that
only one directory will be created, and only if it's used.

The old SPYX_TMP path is marked with a deprecation warning.

src/sage/misc/cython.py

@@ -25,7 +25,7 @@
 
 from sage.env import (SAGE_LOCAL, cython_aliases,
                       sage_include_directories)
-from sage.misc.misc import SPYX_TMP
+from sage.misc.misc import spyx_tmp
 from .temporary_file import tmp_filename
 from sage.repl.user_globals import get_globals
 from sage.misc.sage_ostools import restore_cwd, redirection
@@ -229,9 +229,9 @@ def cython(filename, verbose=0, compile_message=False,
     base = sanitize(base)
 
     # This is the *temporary* directory where we store the pyx file.
-    # This is deleted when Sage exits, which means pyx files must be
-    # rebuilt every time Sage is restarted at present.
-    target_dir = os.path.join(SPYX_TMP, base)
+    # spyx_tmp changes when we start Sage, so old (but not stale) pyx
+    # files must be rebuilt at the moment.
+    target_dir = os.path.join(spyx_tmp(), base)
 
     # Build directory for Cython/distutils
     build_dir = os.path.join(target_dir, "build")

src/sage/misc/misc.py

@@ -46,6 +46,7 @@
 
 from .lazy_string import lazy_string
 from sage.env import DOT_SAGE, HOSTNAME
+from sage.misc.cachefunc import cached_function
 from sage.misc.lazy_import import lazy_import
 
 lazy_import("sage.misc.call", ["AttrCallObject", "attrcall", "call_method"],
@@ -247,15 +248,38 @@ def ECL_TMP():
 
 @lazy_string
 def SPYX_TMP():
-    """
+    r"""
     EXAMPLES::
 
         sage: from sage.misc.misc import SPYX_TMP
         sage: SPYX_TMP
-        l'.../temp/.../spyx'
+        doctest:warning...
+        DeprecationWarning: SPYX_TMP is deprecated;
+        use sage.misc.misc.spyx_tmp instead
+        See https://trac.sagemath.org/33213 for details.
+        ...
+
     """
-    return os.path.join(str(SAGE_TMP), 'spyx')
+    from sage.misc.superseded import deprecation
+    deprecation(33213, "SPYX_TMP is deprecated; use sage.misc.misc.spyx_tmp instead")
+    return spyx_tmp()
+
 
+@cached_function
+def spyx_tmp():
+    r"""
+    The temporary directory used to store pyx files.
+
+    We use a cached function for this so that the same temporary
+    directory will always be returned (unless the user shoots himself
+    in the foot). Each temporary directory created is removed when
+    sage terminates using an atexit hook.
+    """
+    import atexit, tempfile
+    d = tempfile.TemporaryDirectory()
+    result = os.path.join(d.name, 'spyx')
+    atexit.register(lambda: d.cleanup())
+    return result
 
 @lazy_string
 def SAGE_TMP_INTERFACE():

src/sage/misc/sageinspect.py

@@ -259,9 +259,10 @@ def _extract_embedded_position(docstring):
         ....:     print(f.read())
         cpdef test_funct(x,y): return
 
-    Ensure that the embedded filename of the compiled function is correct.  In
-    particular it should be relative to ``SPYX_TMP`` in order for certain
-    documentation functions to work properly.  See :trac:`24097`::
+    Ensure that the embedded filename of the compiled function is
+    correct.  In particular it should be relative to ``spyx_tmp()`` in
+    order for certain documentation functions to work properly.  See
+    :trac:`24097`::
 
         sage: from sage.env import DOT_SAGE
         sage: from sage.misc.sage_ostools import restore_cwd
@@ -293,10 +294,10 @@ def _extract_embedded_position(docstring):
         # Try some common path prefixes for Cython modules built by/for Sage
         # 1) Module in the sage src tree
         # 2) Module compiled by Sage's inline cython() compiler
-        from sage.misc.misc import SPYX_TMP
+        from sage.misc.misc import spyx_tmp
         try_filenames = [
             os.path.join(SAGE_LIB, raw_filename),
-            os.path.join(SPYX_TMP, '_'.join(raw_filename.split('_')[:-1]),
+            os.path.join(spyx_tmp(), '_'.join(raw_filename.split('_')[:-1]),
                          raw_filename)
         ]
         for try_filename in try_filenames:
@@ -2430,9 +2431,9 @@ class Element(object):
             source_lines = f.readlines()
     except IOError:
         try:
-            from sage.misc.misc import SPYX_TMP
+            from sage.misc.misc import spyx_tmp
             raw_name = filename.split('/')[-1]
-            newname = os.path.join(SPYX_TMP, '_'.join(raw_name.split('_')[:-1]), raw_name)
+            newname = os.path.join(spyx_tmp(), '_'.join(raw_name.split('_')[:-1]), raw_name)
             with open(newname) as f:
                 source_lines = f.readlines()
         except IOError: