Fix build-time Python configuration

Apply various fixes and tweaks to Python configuration logic implemented
in the "configure" script:

  - Prevent PYTHON_INSTALL_DIR, which holds the value passed to the
    --with-python-install-dir option, from being set to "unspec" by
    default as this breaks installing Python modules when the
    --with-python-install-dir option is not used.

  - Make the --with-python-install-dir option also work when the Python
    interpreter is specified explicitly (using --with-python=<...>).

  - Improve contents and placement of error messages.

  - Reduce duplication of code checking Python dependencies.

  - Use Autoconf macros AS_CASE() and AS_IF() instead of plain shell
    code.

  - Update comments.  Capitalize the word "Python" when referring to the
    language itself rather than a specific executable.

(cherry picked from commit ed4c700c33e7da10eb45166bac1467c868c0a376)

diff --git a/configure b/configure
index 34f5ad4d3272018a553c933ef540c7ac10ac6bda..581109592b860ec4815081606fdd8c467c27c759 100755 (executable)
--- a/configure
+++ b/configure
@@ -1778,7 +1778,7 @@ Optional Packages:
   --with-gnu-ld           assume the C compiler uses GNU ld [default=no]
   --with-sysroot[=DIR]    Search for dependent libraries within DIR (or the
                           compiler's sysroot if not specified).
-  --with-python=PATH      specify path to python interpreter
+  --with-python=PATH      specify path to Python interpreter
   --with-python-install-dir=PATH
                           installation directory for Python modules
   --with-geoip=PATH       Build with GeoIP support (yes|no|path)
@@ -12511,54 +12511,53 @@ done
 
 
 #
-# Python is also optional; it is used by the tools in bin/python.
-# If python is unavailable, we simply don't build those.
+# Python is also optional but required by default so that dnssec-keymgr gets
+# installed unless explicitly prevented by the user using --without-python.
 #
+testminvers='import sys
+if (sys.version_info < (2,7)) or (sys.version_info < (3,2) and sys.version_info >= (3,0)):
+   exit(1)'
+
+testargparse='try: import argparse
+except: exit(1)'
+
+testply='try: import ply
+except: exit(1)'
+
 
 # Check whether --with-python was given.
 if test "${with_python+set}" = set; then :
-  withval=$with_python; use_python="$withval"
+  withval=$with_python;
 else
-  use_python="yes"
+  with_python="python python3 python3.7 python3.6 python3.5 python3.4 python3.3 python3.2 python2 python2.7"
 fi
 
 
 # Check whether --with-python-install-dir was given.
 if test "${with_python_install_dir+set}" = set; then :
-  withval=$with_python_install_dir; use_python_install_dir="$withval"
+  withval=$with_python_install_dir;
 else
-  use_python_install_dir="unspec"
+  with_python_install_dir=""
 fi
 
 
-python="python python3 python3.7 python3.6 python3.5 python3.4 python3.3 python3.2 python2 python2.7"
-
-testargparse='try: import argparse
-except: exit(1)'
-
-testply='try: from ply import *
-except: exit(1)'
-
-testminvers='import sys
-if (sys.version_info < (2,7)) or (sys.version_info < (3,2) and sys.version_info >= (3,0)):
-   exit(1)'
-
-case "$use_python" in
-       no)
-               { $as_echo "$as_me:${as_lineno-$LINENO}: checking for python support" >&5
-$as_echo_n "checking for python support... " >&6; }
-               { $as_echo "$as_me:${as_lineno-$LINENO}: result: disabled" >&5
+if test "$with_python" = "no"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for Python support" >&5
+$as_echo_n "checking for Python support... " >&6; }
+       { $as_echo "$as_me:${as_lineno-$LINENO}: result: disabled" >&5
 $as_echo "disabled" >&6; }
-               ;;
-       yes|*)
-               case "$use_python" in
-               yes|'')
-                       for p in $python
-                       do
-                               for ac_prog in $p
-do
-  # Extract the first word of "$ac_prog", so it can be a program name with args.
-set dummy $ac_prog; ac_word=$2
+else
+  for p in $with_python
+       do
+        case $p in #(
+  /*) :
+    PYTHON="$p" ;; #(
+  *) :
+     ;;
+esac
+
+        # Extract the first word of "$p", so it can be a program name with args.
+set dummy $p; ac_word=$2
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
 $as_echo_n "checking for $ac_word... " >&6; }
 if ${ac_cv_path_PYTHON+:} false; then :
@@ -12597,153 +12596,80 @@ $as_echo "no" >&6; }
 fi
 
 
-  test -n "$PYTHON" && break
-done
+        # Do not cache the result of the check from the previous line.  If the
+        # first found Python interpreter has missing module dependencies and
+        # the result of the above check is cached, subsequent module checks
+        # will erroneously keep on using the cached path to the first found
+        # Python interpreter instead of different ones.
+        unset ac_cv_path_PYTHON
 
-                               if test "X$PYTHON" = "X"; then
-                                       continue;
-                               fi
-                               { $as_echo "$as_me:${as_lineno-$LINENO}: checking python2 version >= 2.7 or python3 version >= 3.2" >&5
-$as_echo_n "checking python2 version >= 2.7 or python3 version >= 3.2... " >&6; }
-                               if ${PYTHON:-false} -c "$testminvers"; then
-                                       { $as_echo "$as_me:${as_lineno-$LINENO}: result: found" >&5
-$as_echo "found" >&6; }
-                               else
-                                       { $as_echo "$as_me:${as_lineno-$LINENO}: result: not found" >&5
-$as_echo "not found" >&6; }
-                                       unset ac_cv_path_PYTHON
-                                       unset PYTHON
-                                       continue
-                               fi
-                               { $as_echo "$as_me:${as_lineno-$LINENO}: checking python module 'argparse'" >&5
-$as_echo_n "checking python module 'argparse'... " >&6; }
-                               if ${PYTHON:-false} -c "$testargparse"; then
-                                       { $as_echo "$as_me:${as_lineno-$LINENO}: result: found" >&5
-$as_echo "found" >&6; }
-                               else
-                                       { $as_echo "$as_me:${as_lineno-$LINENO}: result: not found" >&5
-$as_echo "not found" >&6; }
-                                       unset ac_cv_path_PYTHON
-                                       unset PYTHON
-                                       continue
-                               fi
+        if test -z "$PYTHON"; then :
+  continue
+fi
 
-                               { $as_echo "$as_me:${as_lineno-$LINENO}: checking python module 'ply'" >&5
-$as_echo_n "checking python module 'ply'... " >&6; }
-                               if ${PYTHON:-false} -c "$testply"; then
-                                       { $as_echo "$as_me:${as_lineno-$LINENO}: result: found" >&5
-$as_echo "found" >&6; }
-                                       break
-                               else
-                                       { $as_echo "$as_me:${as_lineno-$LINENO}: result: not found" >&5
-$as_echo "not found" >&6; }
-                                       unset ac_cv_path_PYTHON
-                                       unset PYTHON
-                               fi
-                       done
-                       { $as_echo "$as_me:${as_lineno-$LINENO}: checking for python support" >&5
-$as_echo_n "checking for python support... " >&6; }
-                       if test "X$PYTHON" != "X"
-                       then
-                               PYTHON_INSTALL_DIR="$use_python_install_dir"
-                               PYTHON_INSTALL_LIB="--install-lib=$use_python_install_dir"
-                               { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking if $PYTHON is python2 version >= 2.7 or python3 version >= 3.2" >&5
+$as_echo_n "checking if $PYTHON is python2 version >= 2.7 or python3 version >= 3.2... " >&6; }
+        if "$PYTHON" -c "$testminvers" 2>/dev/null; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 $as_echo "yes" >&6; }
-                       else
-                               as_fn_error $? "no; python required for dnssec-keymgr" "$LINENO" 5
-                       fi
-                       ;;
-               *)
-                       case "$use_python" in
-                       /*)
-                               PYTHON="$use_python"
-                               ;;
-                       *)
-                               for ac_prog in $use_python
-do
-  # Extract the first word of "$ac_prog", so it can be a program name with args.
-set dummy $ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_path_PYTHON+:} false; then :
-  $as_echo_n "(cached) " >&6
 else
-  case $PYTHON in
-  [\\/]* | ?:[\\/]*)
-  ac_cv_path_PYTHON="$PYTHON" # Let the user override the test with a path.
-  ;;
-  *)
-  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_path_PYTHON="$as_dir/$ac_word$ac_exec_ext"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-  ;;
-esac
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+               unset PYTHON
+               continue
 fi
-PYTHON=$ac_cv_path_PYTHON
-if test -n "$PYTHON"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PYTHON" >&5
-$as_echo "$PYTHON" >&6; }
+
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking Python module 'argparse'" >&5
+$as_echo_n "checking Python module 'argparse'... " >&6; }
+        if "$PYTHON" -c "$testargparse" 2>/dev/null; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
+               unset PYTHON
+               continue
 fi
 
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking Python module 'ply'" >&5
+$as_echo_n "checking Python module 'ply'... " >&6; }
+        if "$PYTHON" -c "$testply" 2>/dev/null; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+               unset PYTHON
+               continue
+fi
 
-  test -n "$PYTHON" && break
-done
+        # Stop looking any further once we find a Python interpreter
+        # satisfying all requirements.
+        break
+       done
 
-                               ;;
-                       esac
-                       { $as_echo "$as_me:${as_lineno-$LINENO}: checking python2 version >= 2.7 or python3 version >= 3.2" >&5
-$as_echo_n "checking python2 version >= 2.7 or python3 version >= 3.2... " >&6; }
-                       if ${PYTHON:-false} -c "$testminvers"; then
-                               { $as_echo "$as_me:${as_lineno-$LINENO}: result: found" >&5
-$as_echo "found" >&6; }
-                       else
-                               as_fn_error $? "not found" "$LINENO" 5
-                       fi
-                       { $as_echo "$as_me:${as_lineno-$LINENO}: checking python module 'argparse'" >&5
-$as_echo_n "checking python module 'argparse'... " >&6; }
-                       if ${PYTHON:-false} -c "$testargparse"; then
-                               { $as_echo "$as_me:${as_lineno-$LINENO}: result: found, using $PYTHON" >&5
-$as_echo "found, using $PYTHON" >&6; }
-                       else
-                               as_fn_error $? "not found" "$LINENO" 5
-                       fi
-                       { $as_echo "$as_me:${as_lineno-$LINENO}: checking python module 'ply'" >&5
-$as_echo_n "checking python module 'ply'... " >&6; }
-                       if ${PYTHON:-false} -c "$testply"; then
-                               { $as_echo "$as_me:${as_lineno-$LINENO}: result: found, using $PYTHON" >&5
-$as_echo "found, using $PYTHON" >&6; }
-                       else
-                               as_fn_error $? "not found" "$LINENO" 5
-                       fi
-                       ;;
-               esac
-               ;;
-esac
+       if test "X$PYTHON" = "X"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for Python support" >&5
+$as_echo_n "checking for Python support... " >&6; }
+             { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+             as_fn_error $? "Python required for dnssec-keymgr" "$LINENO" 5
+fi
+fi
 
 PYTHON_TOOLS=''
 CHECKDS=''
 COVERAGE=''
 KEYMGR=''
-if test "X$PYTHON" != "X"; then
-       PYTHON_TOOLS=python
-       CHECKDS=checkds
-       COVERAGE=coverage
-       KEYMGR=keymgr
+if test "X$PYTHON" != "X"; then :
+  PYTHON_TOOLS=python
+       CHECKDS=checkds
+       COVERAGE=coverage
+       KEYMGR=keymgr
+       PYTHON_INSTALL_DIR="$with_python_install_dir"
+       if test -n "$with_python_install_dir"; then :
+  PYTHON_INSTALL_LIB="--install-lib=$with_python_install_dir"
+fi
 fi
 
 

diff --git a/configure.ac b/configure.ac
index 42396a0159e0678387d05d20776f7141ab02c5cc..92652d290bf038ddf97eaf93f1b32f72b98d5227 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -236,125 +236,89 @@ AC_PATH_PROGS(PERL, perl5 perl)
 AC_SUBST(PERL)
 
 #
-# Python is also optional; it is used by the tools in bin/python.
-# If python is unavailable, we simply don't build those.
+# Python is also optional but required by default so that dnssec-keymgr gets
+# installed unless explicitly prevented by the user using --without-python.
 #
-AC_ARG_WITH(python,
-           AS_HELP_STRING([--with-python=PATH],
-                          [specify path to python interpreter]),
-           use_python="$withval", use_python="yes")
-AC_ARG_WITH(python-install-dir,
-           AS_HELP_STRING([--with-python-install-dir=PATH],
-                          [installation directory for Python modules]),
-           use_python_install_dir="$withval", use_python_install_dir="unspec")
-
-python="python python3 python3.7 python3.6 python3.5 python3.4 python3.3 python3.2 python2 python2.7"
+testminvers='import sys
+if (sys.version_info < (2,7)) or (sys.version_info < (3,2) and sys.version_info >= (3,0)):
+   exit(1)'
 
 testargparse='try: import argparse
 except: exit(1)'
 
-testply='try: from ply import *
+testply='try: import ply
 except: exit(1)'
 
-testminvers='import sys
-if (sys.version_info < (2,7)) or (sys.version_info < (3,2) and sys.version_info >= (3,0)):
-   exit(1)'
-
-case "$use_python" in
-       no)
-               AC_MSG_CHECKING([for python support])
-               AC_MSG_RESULT([disabled])
-               ;;
-       yes|*)
-               case "$use_python" in
-               yes|'')
-                       for p in $python
-                       do
-                               AC_PATH_PROGS(PYTHON, $p)
-                               if test "X$PYTHON" = "X"; then
-                                       continue;
-                               fi
-                               AC_MSG_CHECKING([python2 version >= 2.7 or python3 version >= 3.2])
-                               if ${PYTHON:-false} -c "$testminvers"; then
-                                       AC_MSG_RESULT([found])
-                               else
-                                       AC_MSG_RESULT([not found])
-                                       unset ac_cv_path_PYTHON
-                                       unset PYTHON
-                                       continue
-                               fi
-                               AC_MSG_CHECKING([python module 'argparse'])
-                               if ${PYTHON:-false} -c "$testargparse"; then
-                                       AC_MSG_RESULT([found])
-                               else
-                                       AC_MSG_RESULT([not found])
-                                       unset ac_cv_path_PYTHON
-                                       unset PYTHON
-                                       continue
-                               fi
-
-                               AC_MSG_CHECKING([python module 'ply'])
-                               if ${PYTHON:-false} -c "$testply"; then
-                                       AC_MSG_RESULT([found])
-                                       break
-                               else
-                                       AC_MSG_RESULT([not found])
-                                       unset ac_cv_path_PYTHON
-                                       unset PYTHON
-                               fi
-                       done
-                       AC_MSG_CHECKING([for python support])
-                       if test "X$PYTHON" != "X"
-                       then
-                               PYTHON_INSTALL_DIR="$use_python_install_dir"
-                               PYTHON_INSTALL_LIB="--install-lib=$use_python_install_dir"
-                               AC_MSG_RESULT([yes])
-                       else
-                               AC_MSG_ERROR([no; python required for dnssec-keymgr])
-                       fi
-                       ;;
-               *)
-                       case "$use_python" in
-                       /*)
-                               PYTHON="$use_python"
-                               ;;
-                       *)
-                               AC_PATH_PROGS(PYTHON, $use_python)
-                               ;;
-                       esac
-                       AC_MSG_CHECKING([python2 version >= 2.7 or python3 version >= 3.2])
-                       if ${PYTHON:-false} -c "$testminvers"; then
-                               AC_MSG_RESULT([found])
-                       else
-                               AC_MSG_ERROR([not found])
-                       fi
-                       AC_MSG_CHECKING([python module 'argparse'])
-                       if ${PYTHON:-false} -c "$testargparse"; then
-                               AC_MSG_RESULT([found, using $PYTHON])
-                       else
-                               AC_MSG_ERROR([not found])
-                       fi
-                       AC_MSG_CHECKING([python module 'ply'])
-                       if ${PYTHON:-false} -c "$testply"; then
-                               AC_MSG_RESULT([found, using $PYTHON])
-                       else
-                               AC_MSG_ERROR([not found])
-                       fi
-                       ;;
-               esac
-               ;;
-esac
+AC_ARG_WITH([python],
+           AS_HELP_STRING([--with-python=PATH],
+                          [specify path to Python interpreter]),
+           [], [with_python="python python3 python3.7 python3.6 python3.5 python3.4 python3.3 python3.2 python2 python2.7"])
+AC_ARG_WITH([python-install-dir],
+           AS_HELP_STRING([--with-python-install-dir=PATH],
+                          [installation directory for Python modules]),
+           [], with_python_install_dir="")
+
+AS_IF([test "$with_python" = "no"],
+      [AC_MSG_CHECKING([for Python support])
+       AC_MSG_RESULT([disabled])],
+      [for p in $with_python
+       do
+        AS_CASE([$p],
+                [/*],[PYTHON="$p"])
+
+        AC_PATH_PROG([PYTHON], [$p])
+        # Do not cache the result of the check from the previous line.  If the
+        # first found Python interpreter has missing module dependencies and
+        # the result of the above check is cached, subsequent module checks
+        # will erroneously keep on using the cached path to the first found
+        # Python interpreter instead of different ones.
+        unset ac_cv_path_PYTHON
+
+        AS_IF([test -z "$PYTHON"], [continue])
+
+        AC_MSG_CHECKING([if $PYTHON is python2 version >= 2.7 or python3 version >= 3.2])
+        AS_IF(["$PYTHON" -c "$testminvers" 2>/dev/null],
+              [AC_MSG_RESULT([yes])],
+              [AC_MSG_RESULT([no])
+               unset PYTHON
+               continue])
+
+        AC_MSG_CHECKING([Python module 'argparse'])
+        AS_IF(["$PYTHON" -c "$testargparse" 2>/dev/null],
+              [AC_MSG_RESULT([yes])],
+              [AC_MSG_RESULT([no])
+               unset PYTHON
+               continue])
+
+        AC_MSG_CHECKING([Python module 'ply'])
+        AS_IF(["$PYTHON" -c "$testply" 2>/dev/null],
+              [AC_MSG_RESULT([yes])],
+              [AC_MSG_RESULT([no])
+               unset PYTHON
+               continue])
+
+        # Stop looking any further once we find a Python interpreter
+        # satisfying all requirements.
+        break
+       done
+
+       AS_IF([test "X$PYTHON" = "X"],
+            [AC_MSG_CHECKING([for Python support])
+             AC_MSG_RESULT([no])
+             AC_MSG_ERROR([Python required for dnssec-keymgr])])])
 
 PYTHON_TOOLS=''
 CHECKDS=''
 COVERAGE=''
 KEYMGR=''
-if test "X$PYTHON" != "X"; then
-       PYTHON_TOOLS=python
-       CHECKDS=checkds
-       COVERAGE=coverage
-       KEYMGR=keymgr
-fi
+AS_IF([test "X$PYTHON" != "X"],
+      [PYTHON_TOOLS=python
+       CHECKDS=checkds
+       COVERAGE=coverage
+       KEYMGR=keymgr
+       PYTHON_INSTALL_DIR="$with_python_install_dir"
+       AS_IF([test -n "$with_python_install_dir"],
+            [PYTHON_INSTALL_LIB="--install-lib=$with_python_install_dir"])])
 AC_SUBST(CHECKDS)
 AC_SUBST(COVERAGE)
 AC_SUBST(KEYMGR)