Can build both either as shared or static.

meson.build

@@ -1,8 +1,13 @@
 project('zlib', 'c')
 
-zlib = static_library('z',
-'adler32.c', 'crc32.c', 'deflate.c', 'infback.c', 'inffast.c', 'inflate.c', 
+src = ['adler32.c', 'crc32.c', 'deflate.c', 'infback.c', 'inffast.c', 'inflate.c',
 'inftrees.c', 'trees.c', 'zutil.c',
-'compress.c', 'uncompr.c', 'gzclose.c', 'gzlib.c', 'gzread.c', 'gzwrite.c')
+'compress.c', 'uncompr.c', 'gzclose.c', 'gzlib.c', 'gzread.c', 'gzwrite.c']
+
+if get_option('shared_lib')
+  zlib = shared_library('z', src)
+else
+  zlib = static_library('z', src)
+endif
 
 incdir = include_directories('.')

meson_options.txt

@@ -0,0 +1 @@
+option('shared_lib', type : 'boolean', value : false)

upstream.wrap

@@ -4,4 +4,3 @@ directory = zlib-1.2.8
 source_url = http://zlib.net/zlib-1.2.8.tar.gz
 source_filename = zlib-1.2.8.tar.gz
 source_hash = 36658cb768a54c1d4dec43c3116c27ed893e88b02ecfcb44f2166f9c0b7f2a0d
-