scons: fix sqlite_rtree check + support configuring freetype and xml2 without config scripts

SConstruct

@@ -85,10 +85,11 @@ pretty_dep_names = {
     'm':'Basic math library, part of C++ stlib',
     'pkg-config':'pkg-config tool | more info: http://pkg-config.freedesktop.org',
     'pg_config':'pg_config program | try setting PG_CONFIG SCons option',
-    'xml2-config':'xml2-config program | try setting XML2_CONFIG SCons option',
+    'xml2-config':'xml2-config program | try setting XML2_CONFIG SCons option or avoid the need for xml2-config command by configuring with XML2_LIBS & XML2_INCLUDES',
-    'libxml2':'libxml2 library | try setting XML2_CONFIG SCons option to point to location of xml2-config program',
+    'libxml2':'libxml2 library | try setting XML2_CONFIG SCons option to point to location of xml2-config program or configure with XML2_LIBS & XML2_INCLUDES',
     'gdal-config':'gdal-config program | try setting GDAL_CONFIG SCons option',
-    'freetype-config':'freetype-config program | try setting FREETYPE_CONFIG SCons option',
+    'freetype-config':'freetype-config program | try setting FREETYPE_CONFIG SCons option or configure with FREETYPE_LIBS & FREETYPE_INCLUDES',
+    'freetype':'libfreetype library | try setting FREETYPE_CONFIG SCons option or configure with FREETYPE_LIBS & FREETYPE_INCLUDES',
     'osm':'more info: https://github.com/mapnik/mapnik/wiki/OsmPlugin',
     'boost_regex_icu':'libboost_regex built with optional ICU unicode support is needed for unicode regex support in mapnik.',
     'sqlite_rtree':'The SQLite plugin requires libsqlite3 built with RTREE support (-DSQLITE_ENABLE_RTREE=1)',
@@ -346,6 +347,10 @@ opts.AddVariables(
     BoolVariable('PROJ', 'Build Mapnik with proj4 support to enable transformations between many different projections', 'True'),
     PathVariable('PROJ_INCLUDES', 'Search path for PROJ.4 include files', '/usr/include', PathVariable.PathAccept),
     PathVariable('PROJ_LIBS', 'Search path for PROJ.4 library files', '/usr/' + LIBDIR_SCHEMA_DEFAULT, PathVariable.PathAccept),
+    ('FREETYPE_INCLUDES', 'Search path for Freetype include files', ''),
+    ('FREETYPE_LIBS', 'Search path for Freetype library files', ''),
+    ('XML2_INCLUDES', 'Search path for libxml2 include files', ''),
+    ('XML2_LIBS', 'Search path for libxml2 library files', ''),
     ('PKG_CONFIG_PATH', 'Use this path to point pkg-config to .pc files instead of the PKG_CONFIG_PATH environment setting',''),
 
     # Variables affecting rendering back-ends
@@ -1202,12 +1207,26 @@ if not preconfigured:
         env.AppendUnique(CPPPATH = os.path.realpath(inc_path))
         env.AppendUnique(LIBPATH = os.path.realpath(lib_path))
 
-    if conf.parse_config('FREETYPE_CONFIG'):
+    REQUIRED_LIBSHEADERS = [
+        ['z', 'zlib.h', True,'C'],
+        [env['ICU_LIB_NAME'],'unicode/unistr.h',True,'C++'],
+    ]
+
+    if env.get('FREETYPE_LIBS') or env.get('FREETYPE_INCLUDES'):
+        REQUIRED_LIBSHEADERS.append(['freetype','ft2build.h',True,'C'])
+        if env.get('FREETYPE_INCLUDES'):
+            inc_path = env['FREETYPE_INCLUDES']
+            env.AppendUnique(CPPPATH = os.path.realpath(inc_path))
+        if env.get('FREETYPE_LIBS'):
+            lib_path = env['FREETYPE_LIBS']
+            env.AppendUnique(LIBPATH = os.path.realpath(lib_path))
+    elif conf.parse_config('FREETYPE_CONFIG'):
         # check if freetype links to bz2
         if env['RUNTIME_LINK'] == 'static':
             temp_env = env.Clone()
             temp_env['LIBS'] = []
             try:
+                # TODO - freetype-config accepts --static as of v2.5.3
                 temp_env.ParseConfig('%s --libs' % env['FREETYPE_CONFIG'])
                 if 'bz2' in temp_env['LIBS']:
                     env['EXTRA_FREETYPE_LIBS'].append('bz2')
@@ -1216,16 +1235,19 @@ if not preconfigured:
 
     # libxml2 should be optional but is currently not
     # https://github.com/mapnik/mapnik/issues/913
-    if conf.parse_config('XML2_CONFIG',checks='--cflags'):
+    if env.get('XML2_LIBS') or env.get('XML2_INCLUDES'):
+        REQUIRED_LIBSHEADERS.append(['libxml2','libxml/parser.h',True,'C'])
+        if env.get('XML2_INCLUDES'):
+            inc_path = env['XML2_INCLUDES']
+            env.AppendUnique(CPPPATH = os.path.realpath(inc_path))
+        if env.get('XML2_LIBS'):
+            lib_path = env['XML2_LIBS']
+            env.AppendUnique(LIBPATH = os.path.realpath(lib_path))
+    elif conf.parse_config('XML2_CONFIG',checks='--cflags'):
         env['HAS_LIBXML2'] = True
     else:
         env['MISSING_DEPS'].append('libxml2')
 
-    REQUIRED_LIBSHEADERS = [
-        ['z', 'zlib.h', True,'C'],
-        [env['ICU_LIB_NAME'],'unicode/unistr.h',True,'C++'],
-    ]
-
     if conf.CheckHasDlfcn():
         env.Append(CPPDEFINES = '-DMAPNIK_HAS_DLCFN')
     else:
@@ -1443,7 +1465,7 @@ if not preconfigured:
                         sqlite_backup = env.Clone().Dictionary()
                         # if statically linking, on linux we likely
                         # need to link sqlite to pthreads and dl
-                        if env['RUNTIME_LINK'] == 'static':
+                        if env['RUNTIME_LINK'] == 'static' and not env['PLATFORM'] == 'Darwin':
                             if CHECK_PKG_CONFIG and conf.CheckPKG('sqlite3'):
                                 sqlite_env = env.Clone()
                                 try:
@@ -1453,7 +1475,15 @@ if not preconfigured:
                                             env["SQLITE_LINKFLAGS"].append(lib)
                                             env.Append(LIBS=lib)
                                 except OSError,e:
-                                    pass
+                                    for lib in ["sqlite3","dl","pthread"]:
+                                        if not lib in env['LIBS']:
+                                            env["SQLITE_LINKFLAGS"].append("lib")
+                                            env.Append(LIBS=lib)
+                            else:
+                                for lib in ["sqlite3","dl","pthread"]:
+                                    if not lib in env['LIBS']:
+                                        env["SQLITE_LINKFLAGS"].append("lib")
+                                        env.Append(LIBS=lib)
                         SQLITE_HAS_RTREE = conf.sqlite_has_rtree()
                         if not SQLITE_HAS_RTREE:
                             env.Replace(**sqlite_backup)