notmuch/configure

#! /bin/sh

set -u

# Test whether this shell is capable of parameter substring processing.
( option='a/b'; : ${option#*/} ) 2>/dev/null || {
    echo "
The shell interpreting '$0' is lacking some required features.

To work around this problem you may try to execute:

    ksh $0 $*
 or
    bash $0 $*
"
    exit 1
}

# Store original IFS value so it can be changed (and restored) in many places.
readonly DEFAULT_IFS="$IFS"

# The top-level directory for the source. This ./configure and all Makefiles
# are good with ${srcdir} usually being relative. Some components (e.g. tests)
# are executed in subdirectories and for those it is simpler to use
# ${NOTMUCH_SRCDIR} which holds absolute path to the source.
srcdir=$(dirname "$0")
NOTMUCH_SRCDIR=$(cd "$srcdir" && pwd)

subdirs="util compat lib parse-time-string completion doc emacs"
subdirs="${subdirs} performance-test test test/test-databases"
subdirs="${subdirs} bindings"

# For a non-srcdir configure invocation (such as ../configure), create
# the directory structure and copy Makefiles.
if [ "$srcdir" != "." ]; then

    for dir in . ${subdirs}; do
	mkdir -p "$dir"
	cp "$srcdir"/"$dir"/Makefile.local "$dir"
	cp "$srcdir"/"$dir"/Makefile "$dir"
    done

    # Emacs only likes to generate compiled files next to the .el files
    # by default so copy these as well (which is not ideal).
    cp -a "$srcdir"/emacs/*.el emacs

    # We were not able to create fully working Makefile using ruby mkmf.rb
    # so ruby bindings source files are copied as well (ditto -- not ideal).
    mkdir bindings/ruby
    cp -a "$srcdir"/bindings/ruby/*.[ch] bindings/ruby
    cp -a "$srcdir"/bindings/ruby/extconf.rb bindings/ruby
fi

# Set several defaults (optionally specified by the user in
# environment variables)
BASHCMD=${BASHCMD:-bash}
PERL=${PERL:-perl}
CC=${CC:-cc}
CXX=${CXX:-c++}
CFLAGS=${CFLAGS:--g -O2}
CPPFLAGS=${CPPFLAGS:-}
CXXFLAGS_for_sh=${CXXFLAGS:-${CFLAGS}}
CXXFLAGS=${CXXFLAGS:-\$(CFLAGS)}
LDFLAGS=${LDFLAGS:-}
XAPIAN_CONFIG=${XAPIAN_CONFIG:-}
PYTHON=${PYTHON:-}
RUBY=${RUBY:-ruby}

# We don't allow the EMACS or GZIP Makefile variables inherit values
# from the environment as we do with CC and CXX above. The reason is
# that these names as environment variables have existing uses other
# than the program name that we want. (EMACS is set to 't' when a
# shell is running within emacs and GZIP specifies arguments to pass
# on the gzip command line).

# Set the defaults for values the user can specify with command-line
# options.
PREFIX=/usr/local
LIBDIR=
WITH_DOCS=1
WITH_API_DOCS=1
WITH_EMACS=1
WITH_DESKTOP=1
WITH_BASH=1
WITH_RUBY=1
WITH_ZSH=1
WITH_RETRY_LOCK=1

usage ()
{
    cat <<EOF
Usage: ./configure [options]...

This script configures notmuch to build on your system.

It verifies that dependencies are available, determines flags needed
to compile and link against various required libraries, and identifies
whether various system functions can be used or if locally-provided
replacements will be built instead.

Finally, it allows you to control various aspects of the build and
installation process.

First, some common variables can specified via environment variables:

	CC		The C compiler to use
	CFLAGS		Flags to pass to the C compiler
	CPPFLAGS	Flags to pass to the C preprocessor
	CXX		The C++ compiler to use
	CXXFLAGS	Flags to pass to the C compiler
	LDFLAGS		Flags to pass when linking

Each of these values can further be controlled by specifying them
later on the "make" command line.

Other environment variables can be used to control configure itself,
(and for which there is no equivalent build-time control):

	XAPIAN_CONFIG	The program to use to determine flags for
			compiling and linking against the Xapian
			library. [$XAPIAN_CONFIG]
	PYTHON		Name of python command to use in
			configure and the test suite.
	RUBY		Name of ruby command to use in
			configure and the test suite.

Additionally, various options can be specified on the configure
command line.

	--prefix=PREFIX	Install files in PREFIX [$PREFIX]

By default, "make install" will install the resulting program to
$PREFIX/bin, documentation to $PREFIX/man, etc. You can
specify an installation prefix other than $PREFIX using
--prefix, for instance:

	./configure --prefix=\$HOME

Fine tuning of some installation directories is available:

	--libdir=DIR		Install libraries to DIR [PREFIX/lib]
	--includedir=DIR	Install header files to DIR [PREFIX/include]
	--mandir=DIR		Install man pages to DIR [PREFIX/share/man]
	--infodir=DIR		Install man pages to DIR [PREFIX/share/man]
	--sysconfdir=DIR	Read-only single-machine data [PREFIX/etc]
	--emacslispdir=DIR	Emacs code [PREFIX/share/emacs/site-lisp]
	--emacsetcdir=DIR	Emacs miscellaneous files [PREFIX/share/emacs/site-lisp]
	--bashcompletiondir=DIR Bash completions files [PREFIX/share/bash-completion/completions]
	--zshcompletiondir=DIR	Zsh completions files [PREFIX/share/zsh/functions/Completion/Unix]

Some features can be disabled (--with-feature=no is equivalent to
--without-feature) :

	--without-bash-completion	Do not install bash completions files
	--without-docs			Do not install documentation
	--without-api-docs		Do not install API man page
	--without-emacs			Do not install lisp file
	--without-desktop		Do not install desktop file
	--without-ruby			Do not install ruby bindings
	--without-zsh-completion	Do not install zsh completions files
	--without-retry-lock		Do not use blocking xapian opens, even if available

Additional options are accepted for compatibility with other
configure-script calling conventions, but don't do anything yet:

	--build=<cpu>-<vendor>-<os>	Currently ignored
	--host=<cpu>-<vendor>-<os>	Currently ignored
	--datadir=DIR			Currently ignored
	--localstatedir=DIR		Currently ignored
	--libexecdir=DIR		Currently ignored
	--disable-maintainer-mode	Currently ignored
	--disable-dependency-tracking	Currently ignored

EOF
}

# Parse command-line options
for option; do
    if [ "${option}" = '--help' ] ; then
	usage
	exit 0
    elif [ "${option%%=*}" = '--prefix' ] ; then
	PREFIX="${option#*=}"
    elif [ "${option%%=*}" = '--libdir' ] ; then
	LIBDIR="${option#*=}"
    elif [ "${option%%=*}" = '--includedir' ] ; then
	INCLUDEDIR="${option#*=}"
    elif [ "${option%%=*}" = '--mandir' ] ; then
	MANDIR="${option#*=}"
    elif [ "${option%%=*}" = '--infodir' ] ; then
	INFODIR="${option#*=}"
    elif [ "${option%%=*}" = '--sysconfdir' ] ; then
	SYSCONFDIR="${option#*=}"
    elif [ "${option%%=*}" = '--emacslispdir' ] ; then
	EMACSLISPDIR="${option#*=}"
    elif [ "${option%%=*}" = '--emacsetcdir' ] ; then
	EMACSETCDIR="${option#*=}"
    elif [ "${option%%=*}" = '--bashcompletiondir' ] ; then
	BASHCOMPLETIONDIR="${option#*=}"
    elif [ "${option%%=*}" = '--zshcompletiondir' ] ; then
	ZSHCOMLETIONDIR="${option#*=}"
    elif [ "${option%%=*}" = '--with-docs' ]; then
	if [ "${option#*=}" = 'no' ]; then
	    WITH_DOCS=0
	    WITH_API_DOCS=0
	else
	    WITH_DOCS=1
	fi
    elif [ "${option}" = '--without-docs' ] ; then
	WITH_DOCS=0
	WITH_API_DOCS=0
    elif [ "${option%%=*}" = '--with-api-docs' ]; then
	if [ "${option#*=}" = 'no' ]; then
	    WITH_API_DOCS=0
	else
	    WITH_API_DOCS=1
	fi
    elif [ "${option}" = '--without-api-docs' ] ; then
	WITH_API_DOCS=0
    elif [ "${option%%=*}" = '--with-emacs' ]; then
	if [ "${option#*=}" = 'no' ]; then
	    WITH_EMACS=0
	else
	    WITH_EMACS=1
	fi
    elif [ "${option}" = '--without-emacs' ] ; then
	WITH_EMACS=0
    elif [ "${option%%=*}" = '--with-desktop' ]; then
	if [ "${option#*=}" = 'no' ]; then
	    WITH_DESKTOP=0
	else
	    WITH_DESKTOP=1
	fi
    elif [ "${option}" = '--without-desktop' ] ; then
	WITH_DESKTOP=0
    elif [ "${option%%=*}" = '--with-bash-completion' ]; then
	if [ "${option#*=}" = 'no' ]; then
	    WITH_BASH=0
	else
	    WITH_BASH=1
	fi
    elif [ "${option}" = '--without-bash-completion' ] ; then
	WITH_BASH=0
    elif [ "${option%%=*}" = '--with-ruby' ]; then
	if [ "${option#*=}" = 'no' ]; then
	    WITH_RUBY=0
	else
	    WITH_RUBY=1
	fi
    elif [ "${option}" = '--without-ruby' ] ; then
	WITH_RUBY=0
    elif [ "${option%%=*}" = '--with-retry-lock' ]; then
	if [ "${option#*=}" = 'no' ]; then
	    WITH_RETRY_LOCK=0
	else
	    WITH_RETRY_LOCK=1
	fi
    elif [ "${option}" = '--without-retry-lock' ] ; then
	WITH_RETRY_LOCK=0
    elif [ "${option%%=*}" = '--with-zsh-completion' ]; then
	if [ "${option#*=}" = 'no' ]; then
	    WITH_ZSH=0
	else
	    WITH_ZSH=1
	fi
    elif [ "${option}" = '--without-zsh-completion' ] ; then
	WITH_ZSH=0
    elif [ "${option%%=*}" = '--build' ] ; then
	true
    elif [ "${option%%=*}" = '--host' ] ; then
	true
    elif [ "${option%%=*}" = '--datadir' ] ; then
	true
    elif [ "${option%%=*}" = '--localstatedir' ] ; then
	true
    elif [ "${option%%=*}" = '--libexecdir' ] ; then
	true
    elif [ "${option}" = '--disable-maintainer-mode' ] ; then
	true
    elif [ "${option}" = '--disable-dependency-tracking' ] ; then
	true
    else
	echo "Unrecognized option: ${option}"
	echo "See:"
	echo "	$0 --help"
	echo ""
	exit 1
    fi
done

# We set this value early, (rather than just while printing the
# Makefile.config file later like most values), because we need to
# actually investigate this value compared to the ldconfig_paths value
# below.
if [ -z "$LIBDIR" ] ; then
    libdir_expanded="${PREFIX}/lib"
else
    # very non-general variable expansion
    libdir_expanded=$(printf %s "$LIBDIR" | sed "s|\${prefix}|${PREFIX}|; s|\$prefix\>|${PREFIX}|; s|//*|/|g")
fi

cat <<EOF
Welcome to Notmuch, a system for indexing, searching and tagging your email.

We hope that the process of building and installing notmuch is quick
and smooth so that you can soon be reading and processing your email
more efficiently than ever.

If anything goes wrong in the configure process, you can override any
decisions it makes by manually editing the Makefile.config file that
it creates. Also please do as much as you can to figure out what could
be different on your machine compared to those of the notmuch
developers. Then, please email those details to the Notmuch list
(notmuch@notmuchmail.org) so that we can hopefully make future
versions of notmuch easier for you to use.

We'll now investigate your system to verify that all required
dependencies are available:

EOF

errors=0
printf "int main(void){return 0;}\n" > minimal.c

printf "Sanity checking C compilation environment... "
test_cmdline="${CC} ${CFLAGS} ${CPPFLAGS} minimal.c ${LDFLAGS} -o minimal"
if  ${test_cmdline} > /dev/null 2>&1
then
    printf "OK.\n"
else
    printf "Fail.\n"
    errors=$((errors + 1))
    printf Executed:; printf ' %s' ${test_cmdline}; echo
    ${test_cmdline}
fi

printf "Sanity checking C++ compilation environment... "
test_cmdline="${CXX} ${CXXFLAGS_for_sh} ${CPPFLAGS} minimal.c ${LDFLAGS} -o minimal"
if ${test_cmdline} > /dev/null 2>&1
then
    printf "OK.\n"
else
    printf "Fail.\n"
    errors=$((errors + 1))
    printf Executed:; printf ' %s' ${test_cmdline}; echo
    ${test_cmdline}
fi
unset test_cmdline

if [ $errors -gt 0 ]; then
    cat <<EOF
*** Error: Initial sanity checking of environment failed.  Please try
running configure in a clean environment, and if the problem persists,
report a bug.
EOF
    rm -f minimal minimal.c
    exit 1
fi

printf "Reading libnotmuch version from source... "
cat > _libversion.c <<EOF
#include <stdio.h>
#include "lib/notmuch.h"
int main(void) {
    printf("libnotmuch_version_major=%d\n",
		LIBNOTMUCH_MAJOR_VERSION);
    printf("libnotmuch_version_minor=%d\n",
		LIBNOTMUCH_MINOR_VERSION);
    printf("libnotmuch_version_release=%d\n",
		LIBNOTMUCH_MICRO_VERSION);
    return 0;
}
EOF
if ${CC} ${CFLAGS} -I"$srcdir" _libversion.c -o _libversion > /dev/null 2>&1 \
       && ./_libversion > _libversion.sh && . ./_libversion.sh
then
    printf "OK.\n"
else
    cat <<EOF

*** Error: Reading lib/notmuch.h failed.
Please try running configure again in a clean environment, and if the
problem persists, report a bug.
EOF
    rm -f _libversion _libversion.c _libversion.sh
    exit 1
fi

if pkg-config --version > /dev/null 2>&1; then
    have_pkg_config=1
else
    have_pkg_config=0
fi

printf "Checking for Xapian development files... "
have_xapian=0
for xapian_config in ${XAPIAN_CONFIG} xapian-config xapian-config-1.3; do
    if ${xapian_config} --version > /dev/null 2>&1; then
	xapian_version=$(${xapian_config} --version | sed -e 's/.* //')
	printf "Yes (%s).\n" ${xapian_version}
	have_xapian=1
	xapian_cxxflags=$(${xapian_config} --cxxflags)
	xapian_ldflags=$(${xapian_config} --libs)
	break
    fi
done
if [ ${have_xapian} = "0" ]; then
    printf "No.\n"
    errors=$((errors + 1))
fi

have_xapian_compact=0
have_xapian_field_processor=0
if [ ${have_xapian} = "1" ]; then
    printf "Checking for Xapian compaction support... "
    cat>_compact.cc<<EOF
#include <xapian.h>
class TestCompactor : public Xapian::Compactor { };
EOF
    if ${CXX} ${CXXFLAGS_for_sh} ${xapian_cxxflags} -c _compact.cc -o _compact.o > /dev/null 2>&1
    then
	have_xapian_compact=1
	printf "Yes.\n"
    else
	printf "No.\n"
	errors=$((errors + 1))
    fi

    rm -f _compact.o _compact.cc

    printf "Checking for Xapian FieldProcessor API... "
    cat>_field_processor.cc<<EOF
#include <xapian.h>
class TitleFieldProcessor : public Xapian::FieldProcessor { };
EOF
    if ${CXX} ${CXXFLAGS_for_sh} ${xapian_cxxflags} -c _field_processor.cc -o _field_processor.o > /dev/null 2>&1
    then
	have_xapian_field_processor=1
	printf "Yes.\n"
    else
	printf "No. (optional)\n"
    fi

    rm -f _field_processor.o _field_processor.cc

    default_xapian_backend=""
    # DB_RETRY_LOCK is only supported on Xapian > 1.3.2
    have_xapian_db_retry_lock=0
    if [ $WITH_RETRY_LOCK = "1" ]; then
	printf "Checking for Xapian lock retry support... "
	cat>_retry.cc<<EOF
#include <xapian.h>
int flag = Xapian::DB_RETRY_LOCK;
EOF
	if ${CXX} ${CXXFLAGS_for_sh} ${xapian_cxxflags} -c _retry.cc -o _retry.o > /dev/null 2>&1
	then
	    have_xapian_db_retry_lock=1
	    printf "Yes.\n"
	else
	    printf "No. (optional)\n"
	fi
	rm -f _retry.o _retry.cc
    fi

    printf "Testing default Xapian backend... "
    cat >_default_backend.cc <<EOF
#include <xapian.h>
int main(int argc, char** argv) {
   Xapian::WritableDatabase db("test.db",Xapian::DB_CREATE_OR_OPEN);
}
EOF
    ${CXX} ${CXXFLAGS_for_sh} ${xapian_cxxflags} _default_backend.cc -o _default_backend ${xapian_ldflags}
    ./_default_backend
    if [ -f test.db/iamglass ]; then
	default_xapian_backend=glass
    else
	default_xapian_backend=chert
    fi
    printf "%s\n" "${default_xapian_backend}";
    rm -rf test.db _default_backend _default_backend.cc
fi

# we need to have a version >= 2.6.5 to avoid a crypto bug. We need
# 2.6.7 for permissive "From " header handling.
GMIME_MINVER=2.6.7
GMIME3_MINVER=3.0.3

printf "Checking for GMime development files... "
if pkg-config --exists "gmime-3.0 > $GMIME3_MINVER"; then
    printf "Yes (3.0).\n"
    have_gmime=1
    gmime_cflags=$(pkg-config --cflags gmime-3.0)
    gmime_ldflags=$(pkg-config --libs gmime-3.0)
    gmime_major=3
    have_gmime_session_keys=1
elif pkg-config --exists "gmime-2.6 >= $GMIME_MINVER"; then
    printf "Yes (2.6).\n"
    have_gmime=1
    gmime_cflags=$(pkg-config --cflags gmime-2.6)
    gmime_ldflags=$(pkg-config --libs gmime-2.6)
    gmime_major=2
    if pkg-config --exists "gmime-2.6 >= 2.6.21"; then
        have_gmime_session_keys=1
    else
        have_gmime_session_keys=0
    fi
else
    have_gmime=0
    have_gmime_session_keys=0
    printf "No.\n"
    errors=$((errors + 1))
fi

# GMime already depends on Glib >= 2.12, but we use at least one Glib
# function that only exists as of 2.22, (g_array_unref)
printf "Checking for Glib development files (>= 2.22)... "
have_glib=0
if pkg-config --exists 'glib-2.0 >= 2.22'; then
    printf "Yes.\n"
    have_glib=1
    # these are included in gmime cflags and ldflags
    # glib_cflags=$(pkg-config --cflags glib-2.0)
    # glib_ldflags=$(pkg-config --libs glib-2.0)
else
    printf "No.\n"
    errors=$((errors + 1))
fi

if ! pkg-config --exists zlib; then
  ${CC} -o compat/gen_zlib_pc "$srcdir"/compat/gen_zlib_pc.c >/dev/null 2>&1 &&
  compat/gen_zlib_pc > compat/zlib.pc &&
  PKG_CONFIG_PATH="$PKG_CONFIG_PATH":compat &&
  export PKG_CONFIG_PATH
  rm -f compat/gen_zlib_pc
fi

printf "Checking for zlib (>= 1.2.5.2)... "
have_zlib=0
if pkg-config --atleast-version=1.2.5.2 zlib; then
    printf "Yes.\n"
    have_zlib=1
    zlib_cflags=$(pkg-config --cflags zlib)
    zlib_ldflags=$(pkg-config --libs zlib)
else
    printf "No.\n"
    errors=$((errors + 1))
fi

printf "Checking for talloc development files... "
if pkg-config --exists talloc; then
    printf "Yes.\n"
    have_talloc=1
    talloc_cflags=$(pkg-config --cflags talloc)
    talloc_ldflags=$(pkg-config --libs talloc)
else
    printf "No.\n"
    have_talloc=0
    talloc_cflags=
    errors=$((errors + 1))
fi

printf "Checking for bash... "
if command -v ${BASHCMD} > /dev/null; then
    have_bash=1
    bash_absolute=$(command -v ${BASHCMD})
    printf "Yes (%s).\n" "$bash_absolute"
else
    have_bash=0
    printf "No. (%s not found)\n" "${BASHCMD}"
fi

printf "Checking for perl... "
if command -v ${PERL} > /dev/null; then
    have_perl=1
    perl_absolute=$(command -v ${PERL})
    printf "Yes (%s).\n" "$perl_absolute"
else
    have_perl=0
    printf "No. (%s not found)\n" "${PERL}"
fi

printf "Checking for python... "
have_python=0

for name in ${PYTHON} python3 python python2; do
    if command -v $name > /dev/null; then
	have_python=1
	python=$name
	printf "Yes (%s).\n" "$name"
	break
    fi
done

if [ $have_python -eq 0 ]; then
    printf "No.\n"
    errors=$((errors + 1))
fi

printf "Checking for valgrind development files... "
if pkg-config --exists valgrind; then
    printf "Yes.\n"
    have_valgrind=1
    valgrind_cflags=$(pkg-config --cflags valgrind)
else
    printf "No (but that's fine).\n"
    have_valgrind=0
    valgrind_cflags=
fi

printf "Checking for bash-completion (>= 1.90)... "
if pkg-config --atleast-version=1.90 bash-completion; then
    printf "Yes.\n"
else
    printf "No (will not install bash completion).\n"
    WITH_BASH=0
fi

if [ -z "${EMACSLISPDIR-}" ]; then
    EMACSLISPDIR="\$(prefix)/share/emacs/site-lisp"
fi

if [ -z "${EMACSETCDIR-}" ]; then
    EMACSETCDIR="\$(prefix)/share/emacs/site-lisp"
fi

printf "Checking if emacs is available... "
if emacs --quick --batch > /dev/null 2>&1; then
    printf "Yes.\n"
    have_emacs=1
else
    printf "No (so will not byte-compile emacs code)\n"
    have_emacs=0
fi

have_doxygen=0
if [ $WITH_API_DOCS = "1" ] ; then
    printf "Checking if doxygen is available... "
    if command -v doxygen > /dev/null; then
	printf "Yes.\n"
	have_doxygen=1
    else
	printf "No (so will not install api docs)\n"
    fi
fi

have_ruby_dev=0
if [ $WITH_RUBY = "1" ] ; then
    printf "Checking for ruby development files... "
    if ${RUBY} -e "require 'mkmf'"> /dev/null 2>&1; then
	printf "Yes.\n"
	have_ruby_dev=1
    else
	printf "No (skipping ruby bindings)\n"
    fi
fi

have_sphinx=0
have_makeinfo=0
have_install_info=0
if [ $WITH_DOCS = "1" ] ; then
    printf "Checking if sphinx is available and supports nroff output... "
    if command -v sphinx-build > /dev/null && ${python} -m sphinx.writers.manpage > /dev/null 2>&1 ; then
	printf "Yes.\n"
	have_sphinx=1
    else
	printf "No (so will not install man pages).\n"
    fi
    printf "Checking if makeinfo is available... "
    if command -v makeinfo > /dev/null; then
	printf "Yes.\n"
	have_makeinfo=1
    else
	printf "No (so will not build info pages).\n"
    fi
    printf "Checking if install-info is available... "
    if command -v install-info > /dev/null; then
	printf "Yes.\n"
	have_install_info=1
    else
	printf "No (so will not install info pages).\n"
    fi
fi

if [ $WITH_DESKTOP = "1" ]; then
    printf "Checking if desktop-file-install is available... "
    if command -v desktop-file-install > /dev/null; then
	printf "Yes.\n"
    else
	printf "No (so will not install .desktop file).\n"
	WITH_DESKTOP=0
    fi
fi

printf "Checking for cppcheck... "
if command -v cppcheck > /dev/null; then
    have_cppcheck=1
    printf "Yes.\n"
else
    have_cppcheck=0
    printf "No.\n"
fi

libdir_in_ldconfig=0

printf "Checking which platform we are on... "
uname=$(uname)
if [ $uname = "Darwin" ] ; then
    printf "Mac OS X.\n"
    platform=MACOSX
    linker_resolves_library_dependencies=0
elif [ $uname = "SunOS" ] ; then
    printf "Solaris.\n"
    platform=SOLARIS
    linker_resolves_library_dependencies=0
elif [ $uname = "FreeBSD" ] ; then
    printf "FreeBSD.\n"
    platform=FREEBSD
    linker_resolves_library_dependencies=0
elif [ $uname = "OpenBSD" ] ; then
    printf "OpenBSD.\n"
    platform=OPENBSD
    linker_resolves_library_dependencies=0
elif [ $uname = "Linux" ] || [ $uname = "GNU" ] ; then
    printf "%s\n" "$uname"
    platform="$uname"
    linker_resolves_library_dependencies=1

    printf "Checking for %s in ldconfig... " "$libdir_expanded"
    ldconfig_paths=$(/sbin/ldconfig -N -X -v 2>/dev/null | sed -n -e 's,^\(/.*\):\( (.*)\)\?$,\1,p')
    # Separate ldconfig_paths only on newline (not on any potential
    # embedded space characters in any filenames). Note, we use a
    # literal newline in the source here rather than something like:
    #
    #	IFS=$(printf '\n')
    #
    # because the shell's command substitution deletes any trailing newlines.
    IFS="
"
    for path in $ldconfig_paths; do
	if [ "$path" -ef "$libdir_expanded" ]; then
	    libdir_in_ldconfig=1
	fi
    done
    IFS=$DEFAULT_IFS
    if [ "$libdir_in_ldconfig" = '0' ]; then
	printf "No (will set RPATH)\n"
    else
	printf "Yes\n"
    fi
else
    printf "Unknown.\n"
    platform="$uname"
    linker_resolves_library_dependencies=0
    cat <<EOF

*** Warning: Unknown platform. Notmuch might or might not build correctly.

EOF
fi

if [ $errors -gt 0 ]; then
    cat <<EOF

*** Error: The dependencies of notmuch could not be satisfied. You will
need to install the following packages before being able to compile
notmuch:

EOF
    if [ $have_python -eq 0 ]; then
	echo "  python interpreter"
    fi
    if [ $have_xapian -eq 0 -o $have_xapian_compact -eq 0 ]; then
	echo "	Xapian library (>= version 1.2.6, including development files such as headers)"
	echo "	https://xapian.org/"
    fi
    if [ $have_zlib -eq 0 ]; then
	echo "	zlib library (>= version 1.2.5.2, including development files such as headers)"
	echo "	https://zlib.net/"
	echo
    fi
    if [ $have_gmime -eq 0 ]; then
	echo "	GMime 2.6 library >= $GMIME_MINVER"
	echo "	(including development files such as headers)"
	echo "	https://github.com/jstedfast/gmime/"
	echo
    fi
    if [ $have_glib -eq 0 ]; then
	echo "	Glib library >= 2.22 (including development files such as headers)"
	echo "	https://ftp.gnome.org/pub/gnome/sources/glib/"
	echo
    fi
    if [ $have_talloc -eq 0 ]; then
	echo "	The talloc library (including development files such as headers)"
	echo "	https://talloc.samba.org/"
	echo
    fi
    cat <<EOF
With any luck, you're using a modern, package-based operating system
that has all of these packages available in the distribution. In that
case a simple command will install everything you need. For example:

On Debian and similar systems:

	sudo apt-get install libxapian-dev libgmime-2.6-dev libtalloc-dev zlib1g-dev

Or on Fedora and similar systems:

	sudo yum install xapian-core-devel gmime-devel libtalloc-devel zlib-devel

On other systems, similar commands can be used, but the details of the
package names may be different.

EOF
    if [ $have_pkg_config -eq 0 ]; then
cat <<EOF
Note: the pkg-config program is not available. This configure script
uses pkg-config to find the compilation flags required to link against
the various libraries needed by notmuch. It's possible you simply need
to install pkg-config with a command such as:

	sudo apt-get install pkg-config
Or:
	sudo yum install pkgconfig

But if pkg-config is not available for your system, then you will need
to modify the configure script to manually set the cflags and ldflags
variables to the correct values to link against each library in each
case that pkg-config could not be used to determine those values.

EOF
    fi
cat <<EOF
When you have installed the necessary dependencies, you can run
configure again to ensure the packages can be found, or simply run
"make" to compile notmuch.

EOF
    exit 1
fi

printf "Checking for canonicalize_file_name... "
if ${CC} -o compat/have_canonicalize_file_name "$srcdir"/compat/have_canonicalize_file_name.c > /dev/null 2>&1
then
    printf "Yes.\n"
    have_canonicalize_file_name=1
else
    printf "No (will use our own instead).\n"
    have_canonicalize_file_name=0
fi
rm -f compat/have_canonicalize_file_name


printf "Checking for getline... "
if ${CC} -o compat/have_getline "$srcdir"/compat/have_getline.c > /dev/null 2>&1
then
    printf "Yes.\n"
    have_getline=1
else
    printf "No (will use our own instead).\n"
    have_getline=0
fi
rm -f compat/have_getline

printf "Checking for strcasestr... "
if ${CC} -o compat/have_strcasestr "$srcdir"/compat/have_strcasestr.c > /dev/null 2>&1
then
    printf "Yes.\n"
    have_strcasestr=1
else
    printf "No (will use our own instead).\n"
    have_strcasestr=0
fi
rm -f compat/have_strcasestr

printf "Checking for strsep... "
if ${CC} -o compat/have_strsep "$srcdir"/compat/have_strsep.c > /dev/null 2>&1
then
    printf "Yes.\n"
    have_strsep="1"
else
    printf "No (will use our own instead).\n"
    have_strsep="0"
fi
rm -f compat/have_strsep

printf "Checking for timegm... "
if ${CC} -o compat/have_timegm "$srcdir"/compat/have_timegm.c > /dev/null 2>&1
then
    printf "Yes.\n"
    have_timegm="1"
else
    printf "No (will use our own instead).\n"
    have_timegm="0"
fi
rm -f compat/have_timegm

printf "Checking for dirent.d_type... "
if ${CC} -o compat/have_d_type "$srcdir"/compat/have_d_type.c > /dev/null 2>&1
then
    printf "Yes.\n"
    have_d_type="1"
else
    printf "No (will use stat instead).\n"
    have_d_type="0"
fi
rm -f compat/have_d_type

printf "Checking for standard version of getpwuid_r... "
if ${CC} -o compat/check_getpwuid "$srcdir"/compat/check_getpwuid.c > /dev/null 2>&1
then
    printf "Yes.\n"
    std_getpwuid=1
else
    printf "No (will define _POSIX_PTHREAD_SEMANTICS to get it).\n"
    std_getpwuid=0
fi
rm -f compat/check_getpwuid

printf "Checking for standard version of asctime_r... "
if ${CC} -o compat/check_asctime "$srcdir"/compat/check_asctime.c > /dev/null 2>&1
then
    printf "Yes.\n"
    std_asctime=1
else
    printf "No (will define _POSIX_PTHREAD_SEMANTICS to get it).\n"
    std_asctime=0
fi
rm -f compat/check_asctime

printf "Checking for rpath support... "
if ${CC} -Wl,--enable-new-dtags -Wl,-rpath,/tmp/ -o minimal minimal.c >/dev/null 2>&1
then
    printf "Yes.\n"
    rpath_ldflags="-Wl,--enable-new-dtags -Wl,-rpath,\$(libdir)"
else
    printf "No (nothing to worry about).\n"
    rpath_ldflags=""
fi

printf "Checking for -Wl,--as-needed... "
if ${CC} -Wl,--as-needed -o minimal minimal.c >/dev/null 2>&1
then
    printf "Yes.\n"
    as_needed_ldflags="-Wl,--as-needed"
else
    printf "No (nothing to worry about).\n"
    as_needed_ldflags=""
fi

printf "Checking for -Wl,--no-undefined... "
if ${CC} -Wl,--no-undefined -o minimal minimal.c >/dev/null 2>&1
then
    printf "Yes.\n"
    no_undefined_ldflags="-Wl,--no-undefined"
else
    printf "No (nothing to worry about).\n"
    no_undefined_ldflags=""
fi

WARN_CXXFLAGS=""
printf "Checking for available C++ compiler warning flags... "
for flag in -Wall -Wextra -Wwrite-strings; do
    if ${CC} $flag -o minimal minimal.c > /dev/null 2>&1
    then
	WARN_CXXFLAGS="${WARN_CXXFLAGS}${WARN_CXXFLAGS:+ }${flag}"
    fi
done
printf "\n\t%s\n" "${WARN_CXXFLAGS}"

WARN_CFLAGS="${WARN_CXXFLAGS}"
printf "Checking for available C compiler warning flags... "
for flag in -Wmissing-declarations; do
    if ${CC} $flag -o minimal minimal.c > /dev/null 2>&1
    then
	WARN_CFLAGS="${WARN_CFLAGS}${WARN_CFLAGS:+ }${flag}"
    fi
done
printf "\n\t%s\n" "${WARN_CFLAGS}"

rm -f minimal minimal.c _libversion.c _libversion _libversion.sh

# construct the Makefile.config
cat > Makefile.config <<EOF
# This Makefile.config was automatically generated by the ./configure
# script of notmuch. If the configure script identified anything
# incorrectly, then you can edit this file to try to correct things,
# but be warned that if configure is run again it will destroy your
# changes, (and this could happen by simply calling "make" if the
# configure script is updated).

# The top-level directory for the source, (the directory containing
# the configure script). This may be different than the build
# directory (the current directory at the time configure was run).
srcdir = ${srcdir}
NOTMUCH_SRCDIR = ${NOTMUCH_SRCDIR}

# subdirectories to build
subdirs = ${subdirs}

configure_options = $@

# We use vpath directives (rather than the VPATH variable) since the
# VPATH variable matches targets as well as prerequisites, (which is
# not useful since then a target left-over from a srcdir build would
# cause a target to not be built in the non-srcdir build).
#
# Also, we don't use a single "vpath % \$(srcdir)" here because we
# don't want the vpath to trigger for our emacs lisp compilation,
# (unless we first find a way to convince emacs to build the .elc
# target in a directory other than the directory of the .el
# prerequisite). In the meantime, we're actually copying in the .el
# files, (which is quite ugly).
vpath %.c \$(srcdir)
vpath %.cc \$(srcdir)
vpath Makefile.% \$(srcdir)
vpath %.py \$(srcdir)
vpath %.rst \$(srcdir)

# Library versions (used to make SONAME)
# The major version of the library interface. This will control the soname.
# As such, this number must be incremented for any incompatible change to
# the library interface, (such as the deletion of an API or a major
# semantic change that breaks formerly functioning code).
#
LIBNOTMUCH_VERSION_MAJOR = ${libnotmuch_version_major}

# The minor version of the library interface. This should be incremented at
# the time of release for any additions to the library interface,
# (and when it is incremented, the release version of the library should
#  be reset to 0).
LIBNOTMUCH_VERSION_MINOR = ${libnotmuch_version_minor}

# The release version the library interface. This should be incremented at
# the time of release if there have been no changes to the interface, (but
# simply compatible changes to the implementation).
LIBNOTMUCH_VERSION_RELEASE = ${libnotmuch_version_release}

# These are derived from the VERSION macros in lib/notmuch.h so
# if you have to change them, something is wrong.

# The C compiler to use
CC = ${CC}

# The C++ compiler to use
CXX = ${CXX}

# Command to execute emacs from Makefiles
EMACS = emacs --quick

# Default FLAGS for C compiler (can be overridden by user such as "make CFLAGS=-g")
CFLAGS = ${CFLAGS}

# Default FLAGS for C preprocessor (can be overridden by user such as "make CPPFLAGS=-I/usr/local/include")
CPPFLAGS = ${CPPFLAGS}

# Default FLAGS for C++ compiler (can be overridden by user such as "make CXXFLAGS=-g")
CXXFLAGS = ${CXXFLAGS}

# Default FLAGS for the linker (can be overridden by user such as "make LDFLAGS=-znow")
LDFLAGS = ${LDFLAGS}

# Flags to enable warnings when using the C++ compiler
WARN_CXXFLAGS=${WARN_CXXFLAGS}

# Flags to enable warnings when using the C compiler
WARN_CFLAGS=${WARN_CFLAGS}

# Name of python interpreter
PYTHON = ${python}

# Name of ruby interpreter
RUBY = ${RUBY}

# The prefix to which notmuch should be installed
# Note: If you change this value here, be sure to ensure that the
# LIBDIR_IN_LDCONFIG value below is still set correctly.
prefix = ${PREFIX}

# The directory to which libraries should be installed
# Note: If you change this value here, be sure to ensure that the
# LIBDIR_IN_LDCONFIG value below is still set correctly.
libdir = ${LIBDIR:=\$(prefix)/lib}

# Whether libdir is in a path configured into ldconfig
LIBDIR_IN_LDCONFIG = ${libdir_in_ldconfig}

# The directory to which header files should be installed
includedir = ${INCLUDEDIR:=\$(prefix)/include}

# The directory to which man pages should be installed
mandir = ${MANDIR:=\$(prefix)/share/man}

# The directory to which man pages should be installed
infodir = ${INFODIR:=\$(prefix)/share/info}

# The directory to which read-only (configuration) files should be installed
sysconfdir = ${SYSCONFDIR:=\$(prefix)/etc}

# The directory to which emacs lisp files should be installed
emacslispdir=${EMACSLISPDIR}

# The directory to which emacs miscellaneous (machine-independent) files should
# be installed
emacsetcdir=${EMACSETCDIR}

# Whether bash exists, and if so where
HAVE_BASH = ${have_bash}
BASH_ABSOLUTE = ${bash_absolute}

# Whether perl exists, and if so where
HAVE_PERL = ${have_perl}
PERL_ABSOLUTE = ${perl_absolute}

# Whether there's an emacs binary available for byte-compiling
HAVE_EMACS = ${have_emacs}

# Whether there's a sphinx-build binary available for building documentation
HAVE_SPHINX=${have_sphinx}

# Whether there's a makeinfo binary available for building info format documentation
HAVE_MAKEINFO=${have_makeinfo}

# Whether there's an install-info binary available for installing info format documentation
HAVE_INSTALL_INFO=${have_install_info}

# Whether there's a doxygen binary available for building api documentation
HAVE_DOXYGEN=${have_doxygen}

# The directory to which desktop files should be installed
desktop_dir = \$(prefix)/share/applications

# The directory to which bash completions files should be installed
bash_completion_dir = ${BASHCOMPLETIONDIR:=\$(prefix)/share/bash-completion/completions}

# The directory to which zsh completions files should be installed
zsh_completion_dir = ${ZSHCOMLETIONDIR:=\$(prefix)/share/zsh/functions/Completion/Unix}

# Whether the canonicalize_file_name function is available (if not, then notmuch will
# build its own version)
HAVE_CANONICALIZE_FILE_NAME = ${have_canonicalize_file_name}

# Whether the cppcheck static checker is available
HAVE_CPPCHECK = ${have_cppcheck}

# Whether the getline function is available (if not, then notmuch will
# build its own version)
HAVE_GETLINE = ${have_getline}

# Are the ruby development files (and ruby) available? If not skip
# building/testing ruby bindings.
HAVE_RUBY_DEV = ${have_ruby_dev}

# Whether the strcasestr function is available (if not, then notmuch will
# build its own version)
HAVE_STRCASESTR = ${have_strcasestr}

# Whether the strsep function is available (if not, then notmuch will
# build its own version)
HAVE_STRSEP = ${have_strsep}

# Whether the timegm function is available (if not, then notmuch will
# build its own version)
HAVE_TIMEGM = ${have_timegm}

# Whether struct dirent has d_type (if not, then notmuch will use stat)
HAVE_D_TYPE = ${have_d_type}

# Whether the GMime version can handle extraction and reuse of session keys
HAVE_GMIME_SESSION_KEYS = ${have_gmime_session_keys}

# Whether the Xapian version in use supports compaction
HAVE_XAPIAN_COMPACT = ${have_xapian_compact}

# Whether the Xapian version in use supports field processors
HAVE_XAPIAN_FIELD_PROCESSOR = ${have_xapian_field_processor}

# Whether the Xapian version in use supports DB_RETRY_LOCK
HAVE_XAPIAN_DB_RETRY_LOCK = ${have_xapian_db_retry_lock}

# Whether the getpwuid_r function is standards-compliant
# (if not, then notmuch will #define _POSIX_PTHREAD_SEMANTICS
# to enable the standards-compliant version -- needed for Solaris)
STD_GETPWUID = ${std_getpwuid}

# Whether the asctime_r function is standards-compliant
# (if not, then notmuch will #define _POSIX_PTHREAD_SEMANTICS
# to enable the standards-compliant version -- needed for Solaris)
STD_ASCTIME = ${std_asctime}

# Supported platforms (so far) are: LINUX, MACOSX, SOLARIS, FREEBSD, OPENBSD
PLATFORM = ${platform}

# Whether the linker will automatically resolve the dependency of one
# library on another (if not, then linking a binary requires linking
# directly against both)
LINKER_RESOLVES_LIBRARY_DEPENDENCIES = ${linker_resolves_library_dependencies}

# Flags needed to compile and link against Xapian
XAPIAN_CXXFLAGS = ${xapian_cxxflags}
XAPIAN_LDFLAGS = ${xapian_ldflags}

# Which backend will Xapian use by default?
DEFAULT_XAPIAN_BACKEND = ${default_xapian_backend}

# Flags needed to compile and link against GMime
GMIME_CFLAGS = ${gmime_cflags}
GMIME_LDFLAGS = ${gmime_ldflags}

# Flags needed to compile and link against zlib
ZLIB_CFLAGS = ${zlib_cflags}
ZLIB_LDFLAGS = ${zlib_ldflags}

# Flags needed to compile and link against talloc
TALLOC_CFLAGS = ${talloc_cflags}
TALLOC_LDFLAGS = ${talloc_ldflags}

# Flags needed to have linker set rpath attribute
RPATH_LDFLAGS = ${rpath_ldflags}

# Flags needed to have linker link only to necessary libraries
AS_NEEDED_LDFLAGS = ${as_needed_ldflags}

# Flags to have the linker flag undefined symbols in object files
NO_UNDEFINED_LDFLAGS = ${no_undefined_ldflags}

# Whether valgrind header files are available
HAVE_VALGRIND = ${have_valgrind}

# And if so, flags needed at compile time for valgrind macros
VALGRIND_CFLAGS = ${valgrind_cflags}

# Support for emacs
WITH_EMACS = ${WITH_EMACS}

# Support for desktop file
WITH_DESKTOP = ${WITH_DESKTOP}

# Support for bash completion
WITH_BASH = ${WITH_BASH}

# Support for zsh completion
WITH_ZSH = ${WITH_ZSH}

# Combined flags for compiling and linking against all of the above
COMMON_CONFIGURE_CFLAGS = \\
	\$(GMIME_CFLAGS) \$(TALLOC_CFLAGS) \$(ZLIB_CFLAGS)	\\
	-DHAVE_VALGRIND=\$(HAVE_VALGRIND) \$(VALGRIND_CFLAGS)	\\
	-DHAVE_GETLINE=\$(HAVE_GETLINE)				\\
	-DWITH_EMACS=\$(WITH_EMACS)				\\
	-DHAVE_CANONICALIZE_FILE_NAME=\$(HAVE_CANONICALIZE_FILE_NAME) \\
	-DHAVE_STRCASESTR=\$(HAVE_STRCASESTR)			\\
	-DHAVE_STRSEP=\$(HAVE_STRSEP)				\\
	-DHAVE_TIMEGM=\$(HAVE_TIMEGM)				\\
	-DHAVE_D_TYPE=\$(HAVE_D_TYPE)				\\
	-DSTD_GETPWUID=\$(STD_GETPWUID)				\\
	-DSTD_ASCTIME=\$(STD_ASCTIME)				\\
	-DHAVE_GMIME_SESSION_KEYS=\$(HAVE_GMIME_SESSION_KEYS)	\\
	-DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT)		\\
	-DSILENCE_XAPIAN_DEPRECATION_WARNINGS			\\
	-DHAVE_XAPIAN_FIELD_PROCESSOR=\$(HAVE_XAPIAN_FIELD_PROCESSOR) \\
	-DHAVE_XAPIAN_DB_RETRY_LOCK=\$(HAVE_XAPIAN_DB_RETRY_LOCK)

CONFIGURE_CFLAGS = \$(COMMON_CONFIGURE_CFLAGS)

CONFIGURE_CXXFLAGS = \$(COMMON_CONFIGURE_CFLAGS) \$(XAPIAN_CXXFLAGS)

CONFIGURE_LDFLAGS =  \$(GMIME_LDFLAGS) \$(TALLOC_LDFLAGS) \$(ZLIB_LDFLAGS) \$(XAPIAN_LDFLAGS)
EOF

# construct the sh.config
cat > sh.config <<EOF
# This sh.config was automatically generated by the ./configure
# script of notmuch.

NOTMUCH_SRCDIR='${NOTMUCH_SRCDIR}'

# Whether the Xapian version in use supports compaction
NOTMUCH_HAVE_XAPIAN_COMPACT=${have_xapian_compact}

# Whether the Xapian version in use supports field processors
NOTMUCH_HAVE_XAPIAN_FIELD_PROCESSOR=${have_xapian_field_processor}

# Whether the Xapian version in use supports lock retry
NOTMUCH_HAVE_XAPIAN_DB_RETRY_LOCK=${have_xapian_db_retry_lock}

# Whether the GMime version can handle extraction and reuse of session keys
NOTMUCH_HAVE_GMIME_SESSION_KEYS=${have_gmime_session_keys}

# Which backend will Xapian use by default?
NOTMUCH_DEFAULT_XAPIAN_BACKEND=${default_xapian_backend}

# do we have man pages?
NOTMUCH_HAVE_MAN=$((have_sphinx))

# Whether bash exists, and if so where
NOTMUCH_HAVE_BASH=${have_bash}
NOTMUCH_BASH_ABSOLUTE=${bash_absolute}

# Whether perl exists, and if so where
NOTMUCH_HAVE_PERL=${have_perl}
NOTMUCH_PERL_ABSOLUTE=${perl_absolute}

# Name of python interpreter
NOTMUCH_PYTHON=${python}

# Name of ruby interpreter
NOTMUCH_RUBY=${RUBY}

# Are the ruby development files (and ruby) available? If not skip
# building/testing ruby bindings.
NOTMUCH_HAVE_RUBY_DEV=${have_ruby_dev}

# Major version of gmime
NOTMUCH_GMIME_MAJOR=${gmime_major}

# Platform we are run on
PLATFORM=${platform}
EOF

# Finally, after everything configured, inform the user how to continue.
cat <<EOF

All required packages were found. You may now run the following
commands to compile and install notmuch:

	make
	sudo make install

EOF