dnl Find the compiler and linker flags for SQLite.
dnl
dnl Finds the compiler and linker flags for linking with the SQLite library.
dnl Provides the --with-sqlite, --with-sqlite-lib, and --with-sqlite-include
dnl configure options to specify non-standard paths to the SQLite libraries or
dnl header files.  Currently, only SQLite 3 is considered sufficient.
dnl
dnl Provides the macros RRA_LIB_SQLITE and RRA_LIB_SQLITE_OPTIONAL and sets
dnl the substitution variables SQLITE_CPPFLAGS, SQLITE_LDFLAGS, and
dnl SQLITE_LIBS.  Also provides RRA_LIB_SQLITE_SWITCH to set CPPFLAGS,
dnl LDFLAGS, and LIBS to include the SQLite libraries, saving the current
dnl values first, and RRA_LIB_SQLITE_RESTORE to restore those settings to
dnl before the last RRA_LIB_SQLITE_SWITCH.  Defines HAVE_SQLITE and sets
dnl rra_use_SQLITE to true if libevent is found.  If it isn't found, the
dnl substitution variables will be empty.
dnl
dnl Depends on the lib-helper.m4 framework.
dnl
dnl The canonical version of this file is maintained in the rra-c-util
dnl package, available at <https://www.eyrie.org/~eagle/software/rra-c-util/>.
dnl
dnl Written by Russ Allbery <eagle@eyrie.org>
dnl Copyright 2014
dnl     The Board of Trustees of the Leland Stanford Junior University
dnl
dnl This file is free software; the authors give unlimited permission to copy
dnl and/or distribute it, with or without modifications, as long as this
dnl notice is preserved.
dnl
dnl SPDX-License-Identifier: FSFULLR

dnl Save the current CPPFLAGS, LDFLAGS, and LIBS settings and switch to
dnl versions that include the libevent flags.  Used as a wrapper, with
dnl RRA_LIB_SQLITE_RESTORE, around tests.
AC_DEFUN([RRA_LIB_SQLITE_SWITCH], [RRA_LIB_HELPER_SWITCH([SQLITE])])

dnl Restore CPPFLAGS, LDFLAGS, and LIBS to their previous values before
dnl RRA_LIB_SQLITE_SWITCH was called.
AC_DEFUN([RRA_LIB_SQLITE_RESTORE], [RRA_LIB_HELPER_RESTORE([SQLITE])])

dnl Checks if SQLite is present.  The single argument, if "true", says to fail
dnl if the SQLite library could not be found.  Prefer probing with pkg-config
dnl if available and the --with flags were not given.
AC_DEFUN([_RRA_LIB_SQLITE_INTERNAL],
[RRA_LIB_HELPER_PATHS([SQLITE])
 AS_IF([test x"$SQLITE_CPPFLAGS" = x && test x"$SQLITE_LDFLAGS" = x],
    [PKG_CHECK_EXISTS([sqlite3],
        [PKG_CHECK_MODULES([SQLITE], [sqlite3])
         SQLITE_CPPFLAGS="$SQLITE_CFLAGS"])])
 AS_IF([test x"$SQLITE_LIBS" = x],
    [RRA_LIB_SQLITE_SWITCH
     LIBS=
     AC_SEARCH_LIBS([sqlite3_open_v2], [sqlite3],
        [SQLITE_LIBS="$LIBS"],
        [AS_IF([test x"$1" = xtrue],
            [AC_MSG_ERROR([cannot find usable SQLite library])])])
     RRA_LIB_SQLITE_RESTORE])
 RRA_LIB_SQLITE_SWITCH
 AC_CHECK_HEADERS([sqlite3.h])
 RRA_LIB_SQLITE_RESTORE])

dnl The main macro for packages with mandatory SQLite 3 support.
AC_DEFUN([RRA_LIB_SQLITE],
[RRA_LIB_HELPER_VAR_INIT([SQLITE])
 RRA_LIB_HELPER_WITH([sqlite], [SQLite], [SQLITE])
 _RRA_LIB_SQLITE_INTERNAL([true])
 rra_use_SQLITE=true
 AC_DEFINE([HAVE_SQLITE], 1, [Define if SQLite is available.])])

dnl The main macro for packages with optional SQLite support.
AC_DEFUN([RRA_LIB_SQLITE_OPTIONAL],
[RRA_LIB_HELPER_VAR_INIT([SQLITE])
 RRA_LIB_HELPER_WITH_OPTIONAL([sqlite], [SQLite], [SQLITE])
 AS_IF([test x"$rra_use_SQLITE" != xfalse],
    [AS_IF([test x"$rra_use_SQLITE" = xtrue],
        [_RRA_LIB_SQLITE_INTERNAL([true])],
        [_RRA_LIB_SQLITE_INTERNAL([false])])])
 AS_IF([test x"$SQLITE_LIBS" != x],
    [rra_use_SQLITE=true
     AC_DEFINE([HAVE_SQLITE], 1, [Define if SQLite is available.])])])