[MachO] Apply the correct calling convention for objc_retain_xN / objc_release_xN

The type library for the Objective-C runtime does not apply the custom
calling conventions these functions use. Detect these functions when
creating symbols for imported functions and apply the custom calling
convention to them.

Fixes https://github.com/Vector35/binaryninja-api/issues/8031.

1 files changed, 11 insertions, 0 deletions

diff --git a/view/macho/machoview.cpp b/view/macho/machoview.cpp
index b1a5bdd9..d4ccf563 100644
--- a/view/macho/machoview.cpp
+++ b/view/macho/machoview.cpp
@@ -2712,6 +2712,17 @@ Ref<Symbol> MachoView::DefineMachoSymbol(
 			}
 		}
 
+		if ((type == ExternalSymbol || type == ImportAddressSymbol)
+			&& (name.find("_objc_retain_x") != std::string::npos || name.find("_objc_release_x") != std::string::npos))
+		{
+			auto x = name.rfind('x');
+			auto num = name.substr(x + 1);
+
+			auto cc = GetDefaultArchitecture()->GetCallingConventionByName("apple-arm64-objc-fast-arc-" + num);
+			if (auto idType = GetTypeByName({"id"}); cc && idType)
+				typeRef = Type::FunctionType(idType, cc, {{"obj", idType}});
+		}
+
 		return std::pair<Ref<Symbol>, Ref<Type>>(
 			new Symbol(type, shortName, fullName, rawName, addr, binding, nameSpace), typeRef);
 	};