C glue generates invalid syntax for function pointer parameters

[sequencer]

When generating C glue code with --c flag, function pointer parameters are rendered with incorrect syntax. The parameter name is placed after the closing parenthesis instead of inside (*).

Reproduction

Input header

typedef struct {
  void *ptr;
} Context;
typedef struct {
  int value;
} Result;
Result registerCallback(Context ctx, void (*callback)(void *), void (*deleteUserData)(void *));

Command:

bindgen --header bug1-function-pointer.h --package test.native --link-name test --llvm-bin $LLVM_BIN_PATH --c --flavour scala-native05 --c-import "bug1-function-pointer.h" --clang-include .

Generated output (invalid):

void __sn_wrap_test_native_registerCallback(Context *ctx, void (*)(void *) callback, void (*)(void *) deleteUserData, Result *____return) {
  Result ____ret = registerCallback(*ctx, callback, deleteUserData);
    memcpy(____return, &____ret, sizeof(Result));
}

Expected output (valid C):

void __sn_wrap_test_native_registerCallback(Context *ctx, void (*callback)(void *), void (*deleteUserData)(void *), Result *____return) {
  Result ____ret = registerCallback(*ctx, callback, deleteUserData);
    memcpy(____return, &____ret, sizeof(Result));
}

Compiler Error

error: expected ')'
void __sn_wrap_test_native_registerCallback(Context *ctx, void (*)(void *) callback, ...
                                                                                 ^

Analysis

In C, function pointer parameter declarations require the parameter name inside the (*):

• Invalid: void (*)(void *) callback
• Valid: void (*callback)(void *)