build: add all configure flags as conditional flags to Swift compiler

waftools/generators/headers.py

@@ -10,6 +10,15 @@ def __write_config_h__(ctx):
     __cp_to_variant__(ctx, ctx.options.variant, 'config.h')
     ctx.end_msg("config.h", "PINK")
 
+def __add_swift_defines__(ctx):
+    if ctx.dependency_satisfied("swift"):
+        ctx.start_msg("Adding conditional Swift flags:")
+        from waflib.Tools.c_config import DEFKEYS, INCKEYS
+        for define in ctx.env[DEFKEYS]:
+            if ctx.is_defined(define) and ctx.get_define(define) == "1":
+                ctx.env.SWIFT_FLAGS.extend(["-D", define])
+        ctx.end_msg("yes")
+
 # Approximately escape the string as C string literal
 def __escape_c_string(s):
     return s.replace("\"", "\\\"").replace("\n", "\\n")
@@ -32,4 +41,5 @@ def __add_mpv_defines__(ctx):
 
 def configure(ctx):
     __add_mpv_defines__(ctx)
+    __add_swift_defines__(ctx)
     __write_config_h__(ctx)