[review] Simplify Python checks in configure.ac

Christian Biesinger (Code Review)
2019-10-23T22:04:20Z

Simplify Python checks in configure.ac

The version checking code is not necessary. It is only used to define
HAVE_LIBPYTHON2_6 or HAVE_LIBPYTHON2_7, which is not used anywhere.

If a version check is desired, the PY_{MAJOR,MINOR}_VERSION macro from
the Python headers can be (and is) used, which does not require updating
configure.ac whenever a new Python version is released.

gdb/ChangeLog:

2019-10-23 Christian Biesinger <cbiesinger@google.com>

* config.in: Regenerate.
* configure: Regenerate.
* configure.ac: Remove the code that uses sed to get the python
version and defines HAVE_LIBPYTHON2_6 / HAVE_LIBPYTHON2_7.

Change-Id: I07073870d9040c2bc8519882c8b3c1368edd4513
---
M gdb/config.in
M gdb/configure
M gdb/configure.ac
3 files changed, 21 insertions(+), 94 deletions(-)

diff --git a/gdb/config.in b/gdb/config.in
index da365a7..a76ac9f 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -246,12 +246,6 @@
/* Define if you have the mpfr library. */
#undef HAVE_LIBMPFR

-/* Define if Python 2.6 is being used. */
-#undef HAVE_LIBPYTHON2_6
-
-/* Define if Python 2.7 is being used. */
-#undef HAVE_LIBPYTHON2_7
-
/* Define to 1 if you have the <libunwind-ia64.h> header file. */
#undef HAVE_LIBUNWIND_IA64_H

diff --git a/gdb/configure b/gdb/configure
index 289c91b..dcd6141 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -10439,32 +10439,12 @@

have_libpython=no
if test "${have_python_config}" = yes; then
- # Determine the Python version by extracting "-lpython<version>"
- # part of the python_libs. <version> is usually X.Y with X and Y
- # being decimal numbers, but can also be XY (seen on Windows).
- #
- # The extraction is performed using sed with a regular expression.
- # Initially, the regexp used was using the '?' quantifier to make
- # the dot in the version number optional. Unfortunately, this
- # does not work with non-GNU versions of sed because, because of
- # what looks like a limitation (the '?' quantifier does not work
- # with back-references). We work around this limitation by using
- # the '*' quantifier instead. It means that, in theory, we might
- # match unexpected version strings such as "-lpython2..7", but
- # this seems unlikely in practice. And even if that happens,
- # an error will be triggered later on, when checking that version
- # number.
- python_version=`echo " ${python_libs} " \
- | sed -e 's,^.* -l\(python[0-9]*[.]*[0-9]*\).*$,\1,'`
- case "${python_version}" in
- python*)

- version=${python_version}

new_CPPFLAGS=${python_includes}
new_LIBS=${python_libs}
- { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ${version}" >&5
-$as_echo_n "checking for ${version}... " >&6; }
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for python" >&5
+$as_echo_n "checking for python... " >&6; }
save_CPPFLAGS=$CPPFLAGS
save_LIBS=$LIBS
CPPFLAGS="$CPPFLAGS $new_CPPFLAGS"
@@ -10482,7 +10462,7 @@
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
- have_libpython=${version}
+ have_libpython=yes
found_usable_python=yes
PYTHON_CPPFLAGS=$new_CPPFLAGS
PYTHON_LIBS=$new_LIBS
@@ -10494,20 +10474,14 @@
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: ${found_usable_python}" >&5
$as_echo "${found_usable_python}" >&6; }

- ;;
- *)
- as_fn_error $? "unable to determine python version from ${python_libs}" "$LINENO" 5
- ;;
- esac
elif test "${have_python_config}" != failed; then
if test "${have_libpython}" = no; then

- version=python2.7

new_CPPFLAGS=${python_includes}
new_LIBS="-lpython2.7 ${python_libs}"
- { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ${version}" >&5
-$as_echo_n "checking for ${version}... " >&6; }
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for python" >&5
+$as_echo_n "checking for python... " >&6; }
save_CPPFLAGS=$CPPFLAGS
save_LIBS=$LIBS
CPPFLAGS="$CPPFLAGS $new_CPPFLAGS"
@@ -10525,7 +10499,7 @@
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
- have_libpython=${version}
+ have_libpython=yes
found_usable_python=yes
PYTHON_CPPFLAGS=$new_CPPFLAGS
PYTHON_LIBS=$new_LIBS
@@ -10540,12 +10514,11 @@
fi
if test "${have_libpython}" = no; then

- version=python2.6

new_CPPFLAGS=${python_includes}
new_LIBS="-lpython2.6 ${python_libs}"
- { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ${version}" >&5
-$as_echo_n "checking for ${version}... " >&6; }
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for python" >&5
+$as_echo_n "checking for python... " >&6; }
save_CPPFLAGS=$CPPFLAGS
save_LIBS=$LIBS
CPPFLAGS="$CPPFLAGS $new_CPPFLAGS"
@@ -10563,7 +10536,7 @@
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
- have_libpython=${version}
+ have_libpython=yes
found_usable_python=yes
PYTHON_CPPFLAGS=$new_CPPFLAGS
PYTHON_LIBS=$new_LIBS
@@ -10577,15 +10550,6 @@

fi
fi
- if test "${have_libpython}" = python2.7 -o "${have_libpython}" = python27; then
-
-$as_echo "#define HAVE_LIBPYTHON2_7 1" >>confdefs.h
-
- elif test "${have_libpython}" = python2.6 -o "${have_libpython}" = python26; then
-
-$as_echo "#define HAVE_LIBPYTHON2_6 1" >>confdefs.h
-
- fi

if test "${have_libpython}" = no; then
case "${with_python}" in
diff --git a/gdb/configure.ac b/gdb/configure.ac
index d929b89..f11dccd 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -691,19 +691,17 @@
# --------------------- #

dnl Utility to simplify finding libpython.
-dnl $1 = pythonX.Y
-dnl $2 = the shell variable to assign the result to
+dnl $1 = the shell variable to assign the result to
dnl If libpython is found we store $version here.
-dnl $3 = additional flags to add to CPPFLAGS
-dnl $4 = additional flags to add to LIBS
+dnl $2 = additional flags to add to CPPFLAGS
+dnl $3 = additional flags to add to LIBS

AC_DEFUN([AC_TRY_LIBPYTHON],
[
- version=$1
- define([have_libpython_var],$2)
- new_CPPFLAGS=$3
- new_LIBS=$4
- AC_MSG_CHECKING([for ${version}])
+ define([have_libpython_var],$1)
+ new_CPPFLAGS=$2
+ new_LIBS=$3
+ AC_MSG_CHECKING([for python])
save_CPPFLAGS=$CPPFLAGS
save_LIBS=$LIBS
CPPFLAGS="$CPPFLAGS $new_CPPFLAGS"
@@ -711,7 +709,7 @@
found_usable_python=no
AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include "Python.h"]],
[[Py_Initialize ();]])],
- [have_libpython_var=${version}
+ [have_libpython_var=yes
found_usable_python=yes
PYTHON_CPPFLAGS=$new_CPPFLAGS
PYTHON_LIBS=$new_LIBS])
@@ -868,47 +866,18 @@

have_libpython=no
if test "${have_python_config}" = yes; then
- # Determine the Python version by extracting "-lpython<version>"
- # part of the python_libs. <version> is usually X.Y with X and Y
- # being decimal numbers, but can also be XY (seen on Windows).
- #
- # The extraction is performed using sed with a regular expression.
- # Initially, the regexp used was using the '?' quantifier to make
- # the dot in the version number optional. Unfortunately, this
- # does not work with non-GNU versions of sed because, because of
- # what looks like a limitation (the '?' quantifier does not work
- # with back-references). We work around this limitation by using
- # the '*' quantifier instead. It means that, in theory, we might
- # match unexpected version strings such as "-lpython2..7", but
- # this seems unlikely in practice. And even if that happens,
- # an error will be triggered later on, when checking that version
- # number.
- python_version=`echo " ${python_libs} " \
- | sed -e 's,^.* -l\(python[[0-9]]*[[.]]*[[0-9]]*\).*$,\1,'`
- case "${python_version}" in
- python*)
- AC_TRY_LIBPYTHON(${python_version}, have_libpython,
- ${python_includes}, ${python_libs})
- ;;
- *)
- AC_MSG_ERROR([unable to determine python version from ${python_libs}])
- ;;
- esac
+ AC_TRY_LIBPYTHON(have_libpython,
+ ${python_includes}, ${python_libs})
elif test "${have_python_config}" != failed; then
if test "${have_libpython}" = no; then
- AC_TRY_LIBPYTHON(python2.7, have_libpython,
+ AC_TRY_LIBPYTHON(have_libpython,
${python_includes}, "-lpython2.7 ${python_libs}")
fi
if test "${have_libpython}" = no; then
- AC_TRY_LIBPYTHON(python2.6, have_libpython,
+ AC_TRY_LIBPYTHON(have_libpython,
${python_includes}, "-lpython2.6 ${python_libs}")
fi
fi
- if test "${have_libpython}" = python2.7 -o "${have_libpython}" = python27; then
- AC_DEFINE(HAVE_LIBPYTHON2_7, 1, [Define if Python 2.7 is being used.])
- elif test "${have_libpython}" = python2.6 -o "${have_libpython}" = python26; then
- AC_DEFINE(HAVE_LIBPYTHON2_6, 1, [Define if Python 2.6 is being used.])
- fi

if test "${have_libpython}" = no; then
case "${with_python}" in

Gerrit-Project: binutils-gdb
Gerrit-Branch: master
Gerrit-Change-Id: I07073870d9040c2bc8519882c8b3c1368edd4513
Gerrit-Change-Number: 241
Gerrit-PatchSet: 1
Gerrit-Owner: Christian Biesinger <cbiesinger@google.com>
Gerrit-MessageType: newchange