[gnuastro-commits] master 481b53a 13/14: -Qunused-arguments now dealt with in CXXFLAGS

[Mohammad Akhlaghi]

branch: master
commit 481b53a1eef9ba62d6d528ab27dcf44811ff95a2
Author: Mohammad Akhlaghi <address@hidden>
Commit: Mohammad Akhlaghi <address@hidden>

    -Qunused-arguments now dealt with in CXXFLAGS
    
    Until now, we would completely disable the C++ check if it didn't recognize
    the `-Qunused-arguments' that `AX_PTHREAD' defines in
    `PTHREAD_CFLAGS'. This was because we were putting `PTHREAD_CFLAGS'
    directly into `CFLAGS' and `LDFLAGS'. Since the latter is used for both C
    and C++, it would cause problems if C++ didn't recognize
    `-Qunused-arguments'.
    
    From this commit onward, we only add `PTHREAD_CFLAGS' to `CFLAGS' and
    `CXXFLAGS' and leave `LDFLAGS' alone. Also, `CXXFLAGS' is checked during
    configuration to see if it contains `-Qunused-arguments'. If so, it will
    check if C++ can compile with it or not. If not, this option will be
    removed from the final `CXXFLAGS'. So now, even if the C++ compiler doesn't
    recognize this option, we don't have a problem.
---
 configure.ac                                 | 25 +++++++++++++++----------
 doc/gnuastro.texi                            | 17 +++++++++++------
 tests/Makefile.am                            | 10 +++-------
 tests/lib/{versioncpp.cpp => versioncxx.cpp} |  0
 tests/lib/{versioncpp.sh => versioncxx.sh}   |  2 +-
 5 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/configure.ac b/configure.ac
index 5175b71..35c9ae5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -62,6 +62,7 @@ AC_SUBST(GAL_LT_VERSION)
 
 # Checks for programs.
 : ${CFLAGS=""}
+: ${CXXFLAGS=""}
 AC_PROG_CC
 AC_PROG_CXX
 gl_EARLY
@@ -88,6 +89,7 @@ AC_DEFINE([IN_GNUASTRO_BUILD], [1], [In building, not usage])
 
 # Generic compiler flags for all sub-directories.
 CFLAGS="-Wall -O3 $CFLAGS"
+CXXFLAGS="-Wall -O3 $CXXFLAGS"
 LDFLAGS="-L\$(top_builddir)/lib $LDFLAGS"
 CPPFLAGS="-I\$(top_srcdir)/lib $CPPFLAGS"
 
@@ -99,6 +101,7 @@ CPPFLAGS="-I\$(top_srcdir)/lib $CPPFLAGS"
 # comes from the GNU Autoconf Archive's ax_pthread.m4, see there for the
 # documentation. Note that
 AX_PTHREAD([],[AC_MSG_ERROR([AC_PACKAGE_NAME Needs POSIX Threads (pthread)])])
+CXXFLAGS="$CXXFLAGS $PTHREAD_CFLAGS"
 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
 LIBS="$PTHREAD_LIBS $LIBS"
 CC="$PTHREAD_CC"
@@ -108,20 +111,22 @@ CC="$PTHREAD_CC"
 
 
 # See if the C++ compiler understands `-Qunused-arguments'. AX_PTHREAD adds
-# this option to LDFLAGS when the C compiler knows this option. But as
-# reported in bug #52490, it can happen that at the same time, the C++
-# compiler doesn't recognize it.
-cpp_Qunused_arguments_problem=no
-for flg in $LDFLAGS; do
+# puts this option in `PTHREAD_CFLAGS' when the C compiler knows this
+# option. We then pass it to CFLAGS and CXXFLAGS above. But as reported in
+# bug #52490, it can happen that sometimes, the C++ compiler doesn't
+# recognize it. So we need to do a separate check for C++.
+cxxflags_tmp=
+for flg in $CXXFLAGS; do
   AS_IF([test "$flg" = \-Qunused-arguments],
         [ AC_LANG(C++)
           AX_CHECK_COMPILE_FLAG([-Qunused-arguments],
-                                [cpp_Qunused_arguments_problem=no],
-                                [cpp_Qunused_arguments_problem=yes])
-          AC_LANG(C) ])
+                                [cxx_Qunused_arguments=yes;
+                                 cxxflags_tmp="$cxxflags_tmp $flg"],
+                                [cxx_Qunused_arguments=no])
+          AC_LANG(C) ],
+        [ cxxflags_tmp="$cxxflags_tmp $flg"])
 done
-AM_CONDITIONAL([COND_NO_CPP_QUNUSED_ARGUMENTS_PROBLEM],
-               [test "x$cpp_Qunused_arguments_problem" = "xno"])
+CXXFLAGS="$cxxflags_tmp"
 
 
 
diff --git a/doc/gnuastro.texi b/doc/gnuastro.texi
index 6b3efbe..f77f851 100644
--- a/doc/gnuastro.texi
+++ b/doc/gnuastro.texi
@@ -24503,12 +24503,17 @@ that invested heavily in Python 2.x cannot benefit 
from Python 3.x or
 future versions any more. Some converters are available, but since they are
 automatic, lots of complications might arise in the address@hidden
 example see @url{https://arxiv.org/abs/1712.00461, Jenness (2017)} which
-describes how LSST is managing the transition.}. If a research project
-begins using Python 3.x today, there is no telling how compatible their
-investments will be when Python 4.x or 5.x will come out. This stems from
-the core principles of Python, which are very useful when you look in the
-`on the go' basis as described before and not future usage. Future-proof
-code (as long as current operating systems will be used) is written in C.
+describes how LSST is managing the transition.}.
+
+If a research project begins using Python 3.x today, there is no telling
+how compatible their investments will be when Python 4.x or 5.x will come
+out. This stems from the core principles of Python, which are very useful
+when you look in the `on the go' basis as described before and not future
+usage. Reproducibility (ability to run the code in the future) is a core
+principal of any scientific result, or the software that produced that
+result. Rebuilding all the dependencies of a software in an obsolete
+language is not easy. Future-proof code (as long as current operating
+systems will be used) is written in C.
 
 The portability of C is best demonstrated by the fact that both C++ and
 Python are part of the C-family of programming languages which also include
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 866486e..5bb9924 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -51,11 +51,6 @@ endif
 if COND_HASGNULIBTOOL
   MAYBE_HASGNULIBTOOL = "yes"
 endif
-if COND_NO_CPP_QUNUSED_ARGUMENTS_PROBLEM
-  MAYBE_VERSIONCPP    = versioncpp
-  MAYBE_VERSIONCPP_SH = lib/versioncpp.sh
-  versioncpp_SOURCES  = lib/versioncpp.cpp
-endif
 if COND_ARITHMETIC
   MAYBE_ARITHMETIC_TESTS = arithmetic/snimage.sh arithmetic/onlynumbers.sh \
   arithmetic/where.sh arithmetic/or.sh
@@ -214,8 +209,9 @@ export hasghostscript=$(MAYBE_HASGHOSTSCRIPT);
 # `TESTS'. So they do not need to be specified as any dependency, they will
 # be present when the `.sh' based tests are run.
 LDADD = -lgnuastro
-check_PROGRAMS = multithread $(MAYBE_VERSIONCPP)
+check_PROGRAMS = multithread versioncxx
 multithread_SOURCES = lib/multithread.c
+versioncxx_SOURCES  = lib/versioncxx.cpp
 lib/multithread.sh: mkprof/mosaic1.sh.log
 
 
@@ -223,7 +219,7 @@ lib/multithread.sh: mkprof/mosaic1.sh.log
 
 # Final Tests
 # ===========
-TESTS = prepconf.sh lib/multithread.sh $(MAYBE_VERSIONCPP_SH)              \
+TESTS = prepconf.sh lib/multithread.sh lib/versioncxx.sh              \
   $(MAYBE_ARITHMETIC_TESTS) $(MAYBE_BUILDPROG_TESTS)                       \
   $(MAYBE_CONVERTT_TESTS) $(MAYBE_CONVOLVE_TESTS) $(MAYBE_COSMICCAL_TESTS) \
   $(MAYBE_CROP_TESTS) $(MAYBE_FITS_TESTS) $(MAYBE_MATCH_TESTS)             \
diff --git a/tests/lib/versioncpp.cpp b/tests/lib/versioncxx.cpp
similarity index 100%
rename from tests/lib/versioncpp.cpp
rename to tests/lib/versioncxx.cpp
diff --git a/tests/lib/versioncpp.sh b/tests/lib/versioncxx.sh
similarity index 97%
rename from tests/lib/versioncpp.sh
rename to tests/lib/versioncxx.sh
index 24cfed2..5438c14 100755
--- a/tests/lib/versioncpp.sh
+++ b/tests/lib/versioncxx.sh
@@ -22,7 +22,7 @@
 # Set the variables (The executable is in the build tree). Do the
 # basic checks to see if the executable is made or if the defaults
 # file exists (basicchecks.sh is in the source tree).
-execname=./versioncpp
+execname=./versioncxx