feat: Simplify Box<T> to *T for C only.

src/bindgen/ir/ty.rs

@@ -433,6 +433,16 @@ impl Type {
                 is_nullable: false,
                 is_ref: false,
             }),
+            "Box"
+                if config.language == Language::C && config.function.swift_name_macro.is_none() =>
+            {
+                Some(Type::Ptr {
+                    ty: Box::new(generic),
+                    is_const: false,
+                    is_nullable: false,
+                    is_ref: false,
+                })
+            }
             "Cell" => Some(generic),
             "ManuallyDrop" | "MaybeUninit" if config.language == Language::C => Some(generic),
             _ => None,

tests/expectations/both/box.c

@@ -0,0 +1,16 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef struct NotReprC_Box_i32 NotReprC_Box_i32;
+
+typedef NotReprC_Box_i32 Foo;
+
+typedef struct MyStruct {
+  int32_t *number;
+} MyStruct;
+
+void delete(int32_t *x);
+
+void root(const Foo *a, const MyStruct *with_box);

tests/expectations/both/box.compat.c

@@ -0,0 +1,24 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef struct NotReprC_Box_i32 NotReprC_Box_i32;
+
+typedef NotReprC_Box_i32 Foo;
+
+typedef struct MyStruct {
+  int32_t *number;
+} MyStruct;
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+void delete(int32_t *x);
+
+void root(const Foo *a, const MyStruct *with_box);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/box.c

@@ -0,0 +1,16 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef struct NotReprC_Box_i32 NotReprC_Box_i32;
+
+typedef NotReprC_Box_i32 Foo;
+
+typedef struct {
+  int32_t *number;
+} MyStruct;
+
+void delete(int32_t *x);
+
+void root(const Foo *a, const MyStruct *with_box);

tests/expectations/box.compat.c

@@ -0,0 +1,24 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef struct NotReprC_Box_i32 NotReprC_Box_i32;
+
+typedef NotReprC_Box_i32 Foo;
+
+typedef struct {
+  int32_t *number;
+} MyStruct;
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+void delete(int32_t *x);
+
+void root(const Foo *a, const MyStruct *with_box);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/tag/box.c

@@ -0,0 +1,16 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+struct NotReprC_Box_i32;
+
+typedef struct NotReprC_Box_i32 Foo;
+
+struct MyStruct {
+  int32_t *number;
+};
+
+void delete(int32_t *x);
+
+void root(const Foo *a, const struct MyStruct *with_box);

tests/expectations/tag/box.compat.c

@@ -0,0 +1,24 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+struct NotReprC_Box_i32;
+
+typedef struct NotReprC_Box_i32 Foo;
+
+struct MyStruct {
+  int32_t *number;
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+void delete(int32_t *x);
+
+void root(const Foo *a, const struct MyStruct *with_box);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/rust/box.skip_cpp.rs

@@ -0,0 +1,16 @@
+#[repr(C)]
+pub struct MyStruct {
+    number: Box<i32>,
+}
+
+pub struct NotReprC<T> {
+    inner: T,
+}
+
+pub type Foo = NotReprC<Box<i32>>;
+
+#[no_mangle]
+pub extern "C" fn root(a: &Foo, with_box: &MyStruct) {}
+
+#[no_mangle]
+pub extern "C" fn delete(x: Box<i32>) {}