From 9ce0e5130503ae65108f3921c6711fb7ff45c5e9 Mon Sep 17 00:00:00 2001
From: Giles Payne <gilespayne@gmail.com>
Date: Sun, 20 Mar 2022 18:47:26 +0900
Subject: [PATCH] Objective-C wrapper header fix-ups to avoid clashes with
 system macros

---
 modules/core/misc/objc/gen_dict.json | 20 ++++++++++++++++++++
 modules/objc/generator/gen_objc.py   | 13 +++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/modules/core/misc/objc/gen_dict.json b/modules/core/misc/objc/gen_dict.json
index 9ade8ccb9f..58300255dc 100644
--- a/modules/core/misc/objc/gen_dict.json
+++ b/modules/core/misc/objc/gen_dict.json
@@ -78,6 +78,26 @@
             "(void)divide:(double)scale src2:(Mat*)src2 dst:(Mat*)dst dtype:(int)dtype" : { "src2" : {"name" : "src"} }
         }
     },
+    "header_fix" : {
+        "Core": {
+            "pow" : {
+                "prolog" : "#pragma push_macro(\"pow\")\n#undef pow",
+                "epilog" : "#pragma pop_macro(\"pow\")"
+            },
+            "sqrt" : {
+                "prolog" : "#pragma push_macro(\"sqrt\")\n#undef sqrt",
+                "epilog" : "#pragma pop_macro(\"sqrt\")"
+            },
+            "exp" : {
+                "prolog" : "#pragma push_macro(\"exp\")\n#undef exp",
+                "epilog" : "#pragma pop_macro(\"exp\")"
+            },
+            "log" : {
+                "prolog" : "#pragma push_macro(\"log\")\n#undef log",
+                "epilog" : "#pragma pop_macro(\"log\")"
+            }
+        }
+    },
     "type_dict" : {
         "Algorithm": {
             "objc_type": "Algorithm*"
diff --git a/modules/objc/generator/gen_objc.py b/modules/objc/generator/gen_objc.py
index 3e3ff8a2b0..83029312b9 100755
--- a/modules/objc/generator/gen_objc.py
+++ b/modules/objc/generator/gen_objc.py
@@ -82,6 +82,9 @@ ManualFuncs = {}
 # { class : { func : { arg_name : {"ctype" : ctype, "attrib" : [attrib]} } } }
 func_arg_fix = {}
 
+# { class : { func : { prolog : "", epilog : "" } } }
+header_fix = {}
+
 # { class : { enum: fixed_enum } }
 enum_fix = {}
 
@@ -479,6 +482,9 @@ class FuncInfo(GeneralInfo):
         self.ctype = re.sub(r"^CvTermCriteria", "TermCriteria", decl[1] or "")
         self.args = []
         func_fix_map = func_arg_fix.get(self.classname or module, {}).get(self.objc_name, {})
+        header_fixes = header_fix.get(self.classname or module, {}).get(self.objc_name, {})
+        self.prolog = header_fixes.get('prolog', None)
+        self.epilog = header_fixes.get('epilog', None)
         for a in decl[3]:
             arg = a[:]
             arg_fix_map = func_fix_map.get(arg[1], {})
@@ -1170,6 +1176,9 @@ class ObjectiveCWrapperGenerator(object):
                     objc_name = fi.objc_name if not constructor else ("init" + ("With" + (args[0].name[0].upper() + args[0].name[1:]) if len(args) > 0 else ""))
                 )
 
+            if fi.prolog is not None:
+                method_declarations.write("\n%s\n\n" % fi.prolog)
+
             method_declarations.write( Template(
 """$prototype$swift_name$deprecation_decl;
 
@@ -1181,6 +1190,9 @@ class ObjectiveCWrapperGenerator(object):
                 )
             )
 
+            if fi.epilog is not None:
+                method_declarations.write("%s\n\n" % fi.epilog)
+
             method_implementations.write( Template(
 """$prototype {$prologue
     $ret_val$obj_deref$cv_name($cv_args)$tail;$epilogue$ret
@@ -1646,6 +1658,7 @@ if __name__ == "__main__":
             AdditionalImports[module] = gen_type_dict.get("AdditionalImports", {})
             ManualFuncs.update(gen_type_dict.get("ManualFuncs", {}))
             func_arg_fix.update(gen_type_dict.get("func_arg_fix", {}))
+            header_fix.update(gen_type_dict.get("header_fix", {}))
             enum_fix.update(gen_type_dict.get("enum_fix", {}))
             const_fix.update(gen_type_dict.get("const_fix", {}))
             namespaces_dict.update(gen_type_dict.get("namespaces_dict", {}))