From c365aaf08a7596de516302326bf9c0146619370c Mon Sep 17 00:00:00 2001
From: Joe Rozner <joe@deadbytes.net>
Date: Sat, 10 Oct 2026 04:46:42 +0000
Subject: [PATCH 1/3] [Rust] Add Platform::register_calling_convention

Expose BNRegisterPlatformCallingConvention so a platform can be given
calling conventions beyond the default/cdecl/stdcall/fastcall/syscall
roles. Like the role setters, it asserts that the calling convention's
architecture matches the platform's.
---
 rust/src/platform.rs   | 21 +++++++++++++++++++++
 rust/tests/platform.rs | 18 ++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/rust/src/platform.rs b/rust/src/platform.rs
index 9de125a1c3..7e41b496b6 100644
--- a/rust/src/platform.rs
+++ b/rust/src/platform.rs
@@ -247,6 +247,27 @@ impl Platform {
         BNSetPlatformSystemCallConvention
     );
 
+    /// Register a calling convention with the platform, adding it to [`Platform::calling_conventions`].
+    ///
+    /// Unlike [`Platform::set_default_calling_convention`] and the other role setters, this does not
+    /// assign the calling convention to a role, it only makes it available on the platform.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the calling convention's architecture does not match the platform's architecture.
+    pub fn register_calling_convention(&self, cc: &CoreCallingConvention) {
+        let arch = self.arch();
+
+        assert!(
+            cc.arch_handle.borrow().as_ref().handle == arch.handle,
+            "use of calling convention with non-matching Platform architecture!"
+        );
+
+        unsafe {
+            BNRegisterPlatformCallingConvention(self.handle, cc.handle);
+        }
+    }
+
     pub fn calling_conventions(&self) -> Array<CoreCallingConvention> {
         unsafe {
             let mut count = 0;
diff --git a/rust/tests/platform.rs b/rust/tests/platform.rs
index 09022ec1c3..fa2136e103 100644
--- a/rust/tests/platform.rs
+++ b/rust/tests/platform.rs
@@ -1,3 +1,4 @@
+use binaryninja::architecture::{ArchitectureExt, CoreArchitecture};
 use binaryninja::headless::Session;
 use binaryninja::platform::Platform;
 
@@ -38,3 +39,20 @@ fn test_platform_calling_conventions() {
     let platform = Platform::by_name("windows-x86_64").expect("windows-x86_64 exists");
     assert_eq!(platform.calling_conventions().len(), 1);
 }
+
+#[test]
+fn test_platform_register_calling_convention() {
+    let _session = Session::new().expect("Failed to initialize session");
+    let arch = CoreArchitecture::by_name("x86_64").expect("x86_64 exists");
+    let platform = Platform::new(&arch, "test-register-cc-x86_64");
+    assert_eq!(platform.calling_conventions().len(), 0);
+
+    let cc = arch
+        .calling_convention_by_name("win64")
+        .expect("win64 calling convention exists");
+    platform.register_calling_convention(&cc);
+
+    let calling_conventions = platform.calling_conventions();
+    assert_eq!(calling_conventions.len(), 1);
+    assert_eq!(calling_conventions.get(0).name(), "win64");
+}

From c7e43b9af80af1378a2b7b54523b073b948fd254 Mon Sep 17 00:00:00 2001
From: Joe Rozner <joe@deadbytes.net>
Date: Sat, 10 Oct 2026 08:07:26 +0000
Subject: [PATCH 2/3] [Rust] Drop a useless as_ref in
 Platform::register_calling_convention

arch_handle is already a CoreArchitecture, so .borrow().as_ref() was a
no-op that clippy flags as useless_asref. Compare the handles directly.
---
 rust/src/platform.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rust/src/platform.rs b/rust/src/platform.rs
index 7e41b496b6..78001f2e37 100644
--- a/rust/src/platform.rs
+++ b/rust/src/platform.rs
@@ -259,7 +259,7 @@ impl Platform {
         let arch = self.arch();
 
         assert!(
-            cc.arch_handle.borrow().as_ref().handle == arch.handle,
+            cc.arch_handle.handle == arch.handle,
             "use of calling convention with non-matching Platform architecture!"
         );
 

From a777f1908c59bb2697f26c7e6e9a3429a1993f0c Mon Sep 17 00:00:00 2001
From: Mason Reed <mason@vector35.com>
Date: Sat, 10 Oct 2026 22:17:29 -0700
Subject: [PATCH 3/3] Use assert_eq

---
 rust/src/platform.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rust/src/platform.rs b/rust/src/platform.rs
index 78001f2e37..b32dec8afd 100644
--- a/rust/src/platform.rs
+++ b/rust/src/platform.rs
@@ -258,8 +258,8 @@ impl Platform {
     pub fn register_calling_convention(&self, cc: &CoreCallingConvention) {
         let arch = self.arch();
 
-        assert!(
-            cc.arch_handle.handle == arch.handle,
+        assert_eq!(
+            cc.arch_handle.handle, arch.handle,
             "use of calling convention with non-matching Platform architecture!"
         );