[patch] Try to use python-config to get python include and lib parameters.

Doug Evans dje@google.com
Fri May 21 05:36:00 GMT 2010


On Thu, May 20, 2010 at 4:04 PM, Doug Evans <dje@google.com> wrote:
> Hi.
>
> Building with a private copy of python, or even the system copy,
> sometimes requires linking with extra libraries.
> These libraries are listed with `python-config --ldflags'.
> [or --libs, but --ldflags also includes any needed -L's]
>
> I will check this in in a few days if there are no objections.
>
> 2010-05-20  Doug Evans  <dje@google.com>
>
>        * configure.ac: Try to use python-config to get python include and lib
>        parameters.
>        * configure: Regenerate.

python-config is a python script so it won't work when build != host.

2010-05-20  Doug Evans  <dje@google.com>

        * configure.ac: For non-canadian-cross builds (build == host),
        try to use python-config to get python include and lib parameters.
        * configure: Regenerate.

Tested with
build=host=target=amd64-linux [with/without python]
build=host=amd64-linux target=arm-eabi [with/without python]
build=amd64-linux host=i386-linux target=arm-eabi [without python]
-------------- next part --------------
2010-05-20  Doug Evans  <dje@google.com>

	* configure.ac: For non-canadian-cross builds (build == host),
	try to use python-config to get python include and lib parameters.
	* configure: Regenerate.

Index: configure.ac
===================================================================
RCS file: /cvs/src/src/gdb/configure.ac,v
retrieving revision 1.117
diff -u -p -r1.117 configure.ac
--- configure.ac	23 Apr 2010 18:07:26 -0000	1.117
+++ configure.ac	21 May 2010 05:12:25 -0000
@@ -589,22 +589,31 @@ else
 fi
 
 dnl Utility to simplify finding libpython.
+dnl $1 = pythonX.Y
+dnl $2 = 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
+
 AC_DEFUN([AC_TRY_LIBPYTHON],
 [
   version=$1
   define([have_libpython_var],$2)
-  define([VERSION],[translit([$1],[abcdefghijklmnopqrstuvwxyz./-],
-                                  [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])])
-  [HAVE_LIB]VERSION=no
+  new_CPPFLAGS=$3
+  new_LIBS=$4
   AC_MSG_CHECKING([for ${version}])
+  save_CPPFLAGS=$CPPFLAGS
   save_LIBS=$LIBS
-  LIBS="$LIBS -l${version}"
+  CPPFLAGS="$CPPFLAGS $new_CPPFLAGS"
+  LIBS="$LIBS $new_LIBS"
+  found_usable_python=no
   AC_LINK_IFELSE(AC_LANG_PROGRAM([[#include "${version}/Python.h"]],
                                  [[Py_Initialize ();]]),
-                 [[HAVE_LIB]VERSION=yes
-                  have_libpython_var=yes],
-                 [LIBS=$save_LIBS])
-  AC_MSG_RESULT([$[HAVE_LIB]VERSION])
+                 [have_libpython_var=${version}
+                  found_usable_python=yes],
+                 [CPPFLAGS=$save_CPPFLAGS
+                  LIBS=$save_LIBS])
+  AC_MSG_RESULT([${found_usable_python}])
 ])
 
 AC_ARG_WITH(python,
@@ -617,45 +626,96 @@ if test "${with_python}" = no; then
   AC_MSG_WARN([python support disabled; some features may be unavailable.])
   have_libpython=no
 else
+  have_python_config=no
   case "${with_python}" in
   yes | auto)
-    # Leave as empty, use defaults.
-    python_includes=
-    python_libs=
+    # We can't use python-config in the non-native case, it's a python script.
+    if test ${build} = ${host}; then
+      AC_PATH_PROG(python_config_path, python-config, missing)
+      if test "${python_config_path}" = missing; then
+        # Perhaps this should be an error, but 7.0 and 7.1 shipped without
+        # checking for python-config so in the interests of not breaking
+        # anything, we follow their behaviour here.
+        python_includes=
+        python_libs=
+      else
+        python_includes=`${python_config_path} --includes`
+        python_libs=`${python_config_path} --ldflags`
+        have_python_config=yes
+      fi
+    else
+      python_includes=
+      python_libs=
+    fi
     ;;
   /*)
-    python_includes="-I${with_python}/include"
-    python_libs="-L${with_python}/lib"
+    if test ${build} = ${host}; then
+      AC_PATH_PROG(python_config_path, python-config, missing,
+                   [PATH = ${with_python}/bin])
+      if test "${python_config_path}" = missing; then
+        # If an explicit path was provided, and we can't find python-config
+        # at that location, flag an error.
+        AC_ERROR(python-config missing from ${with_python}/bin)
+      fi
+      python_includes=`${python_config_path} --includes`
+      python_libs=`${python_config_path} --ldflags`
+      have_python_config=yes
+    else
+      python_includes="-I${with_python}/include"
+      python_libs="-L${with_python}/lib"
+    fi
     ;;
   *)
     AC_ERROR(invalid value for --with-python)
     ;;
   esac
 
-  save_CPPFLAGS=$CPPFLAGS
-  CPPFLAGS="$CPPFLAGS ${python_includes}"
-  save_LIBS=$LIBS
-  LIBS="$LIBS ${python_libs}"
+  # Having "/pythonX.Y" in the include path is awkward.
+  # All those python headers get bubbled up to the top inviting lots
+  # of random collisions.  GDB originally didn't use python-config to
+  # find the compilation parameters and includes "pythonX.Y/" in the
+  # path of the, umm, include file.  So strip away this part of the
+  # output of python-config --includes.
+  python_includes=`echo "${python_includes} " \
+  			| sed -e 's,/python[[0-9]]*[[.]][[0-9]]* , ,g'`
+
+  # If we have python-config, only try the configuration it provides.
+  # Otherwise fallback on the old way of trying different versions of
+  # python in turn.
+
   have_libpython=no
-  if test "${have_libpython}" = no; then
-    AC_TRY_LIBPYTHON(python2.6, have_libpython)
-    if test "${HAVE_LIBPYTHON2_6}" = yes; then
-      AC_DEFINE(HAVE_LIBPYTHON2_6, 1, [Define if Python 2.6 is being used.])
+  if test "${have_python_config}" = yes; then
+    python_version=`echo " ${python_libs} " \
+    			 | sed -e 's,^.* -l\(python[[0-9]]*[[.]][[0-9]]*\) .*$,\1,'`
+    if test "${python_version}" != ""; then
+      AC_TRY_LIBPYTHON(${python_version}, have_libpython,
+                       ${python_includes}, ${python_libs})
+    else
+      AC_MSG_ERROR([unable to determine python version from ${python_libs}])
     fi
-  fi
-  if test ${have_libpython} = no; then
-    AC_TRY_LIBPYTHON(python2.5, have_libpython)
-    if test "${HAVE_LIBPYTHON2_5}" = yes; then
-      AC_DEFINE(HAVE_LIBPYTHON2_5, 1, [Define if Python 2.5 is being used.])
+  else
+    if test "${have_libpython}" = no; then
+      AC_TRY_LIBPYTHON(python2.6, have_libpython,
+                       ${python_includes}, "${python_libs} -lpython2.6")
     fi
-  fi
-  if test ${have_libpython} = no; then
-    AC_TRY_LIBPYTHON(python2.4, have_libpython)
-    if test "${HAVE_LIBPYTHON2_4}" = yes; then
-      AC_DEFINE(HAVE_LIBPYTHON2_4, 1, [Define if Python 2.4 is being used.])
+    if test ${have_libpython} = no; then
+      AC_TRY_LIBPYTHON(python2.5, have_libpython,
+                       ${python_includes}, "${python_libs} -lpython2.5")
     fi
+    if test ${have_libpython} = no; then
+      AC_TRY_LIBPYTHON(python2.4, have_libpython,
+                       ${python_includes}, "${python_libs} -lpython2.4")
+    fi
+  fi
+  if test "${have_libpython}" = python2.6; then
+    AC_DEFINE(HAVE_LIBPYTHON2_6, 1, [Define if Python 2.6 is being used.])
+  elif test "${have_libpython}" = python2.5; then
+    AC_DEFINE(HAVE_LIBPYTHON2_5, 1, [Define if Python 2.5 is being used.])
+  elif test "${have_libpython}" = python2.4; then
+    AC_DEFINE(HAVE_LIBPYTHON2_4, 1, [Define if Python 2.4 is being used.])
   fi
-  if test ${have_libpython} = no; then
+
+  if test "${have_libpython}" = no; then
     case "${with_python}" in
     yes)
       AC_MSG_ERROR([python is missing or unusable])
@@ -667,12 +727,10 @@ else
       AC_MSG_ERROR([no usable python found at ${with_python}])
       ;;
     esac
-    CPPFLAGS=$save_CPPFLAGS
-    LIBS=$save_LIBS
   fi
 fi
 
-if test "${have_libpython}" = yes; then
+if test "${have_libpython}" != no; then
   AC_DEFINE(HAVE_PYTHON, 1, [Define if Python interpreter is being linked in.])
   CONFIG_OBS="$CONFIG_OBS \$(SUBDIR_PYTHON_OBS)"
   CONFIG_DEPS="$CONFIG_DEPS \$(SUBDIR_PYTHON_DEPS)"


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