plpython: Reject Python 2 during build configuration.

Python 2.7 went EOL 2020-01-01 and the support for Python 2 requires a fair
bit of infrastructure. Therefore we are removing Python 2 support in plpython.

This patch just rejects Python 2 during configure / mkvcbuild.pl. Future
commits will remove the code and infrastructure for Python 2 support and
adjust more of the documentation. This way we can see the buildfarm state
after the removal sooner and we can be sure that failures are due to
desupporting Python 2, rather than caused by infrastructure cleanup.

Reviewed-By: Peter Eisentraut 
Discussion: https://postgr.es/m/20211031184548[email protected]

diff --git a/config/python.m4 b/config/python.m4
index c7310ee37d3c18cf9dd84be5e5a4c827801271a5..52f34070dd808f3bea3b020e4528ef81fbdcf9ca 100644 (file)
--- a/config/python.m4
+++ b/config/python.m4
@@ -9,6 +9,9 @@
 # Look for Python and set the output variable 'PYTHON' if found,
 # fail otherwise.
 #
+# Since we are supporting only Python 3.x, prefer python3 to plain python.  If
+# the latter exists at all, it very possibly points to python2.
+
 # As the Python 3 transition happens and PEP 394 isn't updated, we
 # need to cater to systems that don't have unversioned "python" by
 # default.  Some systems ship with "python3" by default and perhaps
@@ -16,7 +19,7 @@
 # "python2" and "python3", in which case it's reasonable to prefer the
 # newer version.
 AC_DEFUN([PGAC_PATH_PYTHON],
-[PGAC_PATH_PROGS(PYTHON, [python python3 python2])
+[PGAC_PATH_PROGS(PYTHON, [python3 python])
 AC_ARG_VAR(PYTHON, [Python program])dnl
 if test x"$PYTHON" = x""; then
   AC_MSG_ERROR([Python not found])
@@ -37,8 +40,8 @@ python_majorversion=`echo "$python_fullversion" | sed '[s/^\([0-9]*\).*/\1/]'`
 python_minorversion=`echo "$python_fullversion" | sed '[s/^[0-9]*\.\([0-9]*\).*/\1/]'`
 python_version=`echo "$python_fullversion" | sed '[s/^\([0-9]*\.[0-9]*\).*/\1/]'`
 # Reject unsupported Python versions as soon as practical.
-if test "$python_majorversion" -lt 3 -a "$python_minorversion" -lt 7; then
-  AC_MSG_ERROR([Python version $python_version is too old (version 2.7 or later is required)])
+if test "$python_majorversion" -lt 3; then
+  AC_MSG_ERROR([Python version $python_version is too old (version 3 or later is required)])
 fi
 
 AC_MSG_CHECKING([for Python sysconfig module])

diff --git a/configure b/configure
index 93055556585a0328aea01fd09b67e2c4b8fb903a..ba635a0062241acc115f38cb0adba0e755137e0d 100755 (executable)
--- a/configure
+++ b/configure
@@ -10280,7 +10280,7 @@ fi
 
 if test "$with_python" = yes; then
   if test -z "$PYTHON"; then
-  for ac_prog in python python3 python2
+  for ac_prog in python3 python
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
@@ -10346,8 +10346,8 @@ python_majorversion=`echo "$python_fullversion" | sed 's/^\([0-9]*\).*/\1/'`
 python_minorversion=`echo "$python_fullversion" | sed 's/^[0-9]*\.\([0-9]*\).*/\1/'`
 python_version=`echo "$python_fullversion" | sed 's/^\([0-9]*\.[0-9]*\).*/\1/'`
 # Reject unsupported Python versions as soon as practical.
-if test "$python_majorversion" -lt 3 -a "$python_minorversion" -lt 7; then
-  as_fn_error $? "Python version $python_version is too old (version 2.7 or later is required)" "$LINENO" 5
+if test "$python_majorversion" -lt 3; then
+  as_fn_error $? "Python version $python_version is too old (version 3 or later is required)" "$LINENO" 5
 fi
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for Python sysconfig module" >&5

diff --git a/doc/src/sgml/install-windows.sgml b/doc/src/sgml/install-windows.sgml
index 30dd0c7f75152024987a0ea03de6d3b13587be31..b3435eabc420fe3ab11bc21035a6875da05c4248 100644 (file)
--- a/doc/src/sgml/install-windows.sgml
+++ b/doc/src/sgml/install-windows.sgml
@@ -136,7 +136,7 @@
   to specify the location of your Python installation,
   put the following in config.pl:
 
-$config->{python} = 'c:\python26';
+$config->{python} = 'c:\python310';
 
   You only need to specify those parameters that are different from what's in
   config_default.pl.

diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index 655095f3b13e249397d29f009defb7ef58645073..094d23c2928c2b00e088f76abbf26e9866a4bad5 100644 (file)
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -196,11 +196,7 @@ su - postgres
       language, you need a Python
       installation with the header files and
       the sysconfig module.  The minimum
-      required version is Python 2.7.
-      Python 3 is supported if it's
-      version 3.2 or later; but see
-      
-      when using Python 3.
+      required version is Python 3.2.
      
 
      
@@ -1868,14 +1864,10 @@ build-postgresql:
        PYTHON
        
         
-         Python interpreter program.  This will be used to
-         determine the dependencies for building PL/Python.  Also,
-         whether Python 2 or 3 is specified here (or otherwise
-         implicitly chosen) determines which variant of the PL/Python
-         language becomes available.  See
-         
-         for more information.  If this is not set, the following are probed
-         in this order: python python3 python2.
+         Python interpreter program.  This will be used to determine the
+         dependencies for building PL/Python.  If this is not set, the
+         following are probed in this order:
+         python3 python.
         
        
       

diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index bab81bd459a981ee62b09962adb7f29b39588073..105f5c72a2da5bad1d94fb9157cd809908c37d9e 100644 (file)
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -490,6 +490,10 @@ sub mkvcbuild
          if (!(defined($pyprefix) && defined($pyver)));
 
        my $pymajorver = substr($pyver, 0, 1);
+
+       die "Python version $pyver is too old (version 3 or later is required)"
+         if int($pymajorver) < 3;
+
        my $plpython = $solution->AddProject('plpython' . $pymajorver,
            'dll', 'PLs', 'src/pl/plpython');
        $plpython->AddIncludeDir($pyprefix . '/include');