bindgen: enable "void prototype" while writing struct field

This fixs typedef's signature in C as well because a typedef statement is
constructed like, "typedef " + field_like_string.

src/bindgen/cdecl.rs

@@ -286,7 +286,7 @@ pub fn write_func<F: Write>(
 }
 
 pub fn write_field<F: Write>(out: &mut SourceWriter<F>, t: &Type, ident: &str) {
-    CDecl::from_type(t).write(out, Some(ident), false);
+    CDecl::from_type(t).write(out, Some(ident), true);
 }
 
 pub fn write_type<F: Write>(out: &mut SourceWriter<F>, t: &Type) {

tests/expectations/both/cdecl.c

@@ -3,15 +3,15 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-typedef void (*A)();
+typedef void (*A)(void);
 
-typedef void (*B)();
+typedef void (*B)(void);
 
 typedef bool (*C)(int32_t, int32_t);
 
 typedef bool (*(*D)(int32_t))(float);
 
-typedef const int32_t (*(*E)())[16];
+typedef const int32_t (*(*E)(void))[16];
 
 typedef const int32_t *F;
 

tests/expectations/both/cdecl.compat.c

@@ -3,15 +3,15 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-typedef void (*A)();
+typedef void (*A)(void);
 
-typedef void (*B)();
+typedef void (*B)(void);
 
 typedef bool (*C)(int32_t, int32_t);
 
 typedef bool (*(*D)(int32_t))(float);
 
-typedef const int32_t (*(*E)())[16];
+typedef const int32_t (*(*E)(void))[16];
 
 typedef const int32_t *F;
 

tests/expectations/both/fns.c

@@ -4,9 +4,9 @@
 #include <stdlib.h>
 
 typedef struct Fns {
-  void (*noArgs)();
+  void (*noArgs)(void);
   void (*anonymousArg)(int32_t);
-  int32_t (*returnsNumber)();
+  int32_t (*returnsNumber)(void);
   int8_t (*namedArgs)(int32_t first, int16_t snd);
   int8_t (*namedArgsWildcards)(int32_t _, int16_t named, int64_t _1);
 } Fns;

tests/expectations/both/fns.compat.c

@@ -4,9 +4,9 @@
 #include <stdlib.h>
 
 typedef struct Fns {
-  void (*noArgs)();
+  void (*noArgs)(void);
   void (*anonymousArg)(int32_t);
-  int32_t (*returnsNumber)();
+  int32_t (*returnsNumber)(void);
   int8_t (*namedArgs)(int32_t first, int16_t snd);
   int8_t (*namedArgsWildcards)(int32_t _, int16_t named, int64_t _1);
 } Fns;

tests/expectations/both/simplify-option-ptr.c

@@ -8,13 +8,13 @@ typedef struct Opaque Opaque;
 typedef struct Foo {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 } Foo;
 
 typedef union Bar {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 } Bar;
 
 void root(const Opaque *a, Opaque *b, Foo c, Bar d);

tests/expectations/both/simplify-option-ptr.compat.c

@@ -8,13 +8,13 @@ typedef struct Opaque Opaque;
 typedef struct Foo {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 } Foo;
 
 typedef union Bar {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 } Bar;
 
 #ifdef __cplusplus

tests/expectations/cdecl.c

@@ -3,15 +3,15 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-typedef void (*A)();
+typedef void (*A)(void);
 
-typedef void (*B)();
+typedef void (*B)(void);
 
 typedef bool (*C)(int32_t, int32_t);
 
 typedef bool (*(*D)(int32_t))(float);
 
-typedef const int32_t (*(*E)())[16];
+typedef const int32_t (*(*E)(void))[16];
 
 typedef const int32_t *F;
 

tests/expectations/cdecl.compat.c

@@ -3,15 +3,15 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-typedef void (*A)();
+typedef void (*A)(void);
 
-typedef void (*B)();
+typedef void (*B)(void);
 
 typedef bool (*C)(int32_t, int32_t);
 
 typedef bool (*(*D)(int32_t))(float);
 
-typedef const int32_t (*(*E)())[16];
+typedef const int32_t (*(*E)(void))[16];
 
 typedef const int32_t *F;
 

tests/expectations/fns.c

@@ -4,9 +4,9 @@
 #include <stdlib.h>
 
 typedef struct {
-  void (*noArgs)();
+  void (*noArgs)(void);
   void (*anonymousArg)(int32_t);
-  int32_t (*returnsNumber)();
+  int32_t (*returnsNumber)(void);
   int8_t (*namedArgs)(int32_t first, int16_t snd);
   int8_t (*namedArgsWildcards)(int32_t _, int16_t named, int64_t _1);
 } Fns;

tests/expectations/fns.compat.c

@@ -4,9 +4,9 @@
 #include <stdlib.h>
 
 typedef struct {
-  void (*noArgs)();
+  void (*noArgs)(void);
   void (*anonymousArg)(int32_t);
-  int32_t (*returnsNumber)();
+  int32_t (*returnsNumber)(void);
   int8_t (*namedArgs)(int32_t first, int16_t snd);
   int8_t (*namedArgsWildcards)(int32_t _, int16_t named, int64_t _1);
 } Fns;

tests/expectations/fns.cpp

@@ -4,9 +4,9 @@
 #include <new>
 
 struct Fns {
-  void (*noArgs)();
+  void (*noArgs)(void);
   void (*anonymousArg)(int32_t);
-  int32_t (*returnsNumber)();
+  int32_t (*returnsNumber)(void);
   int8_t (*namedArgs)(int32_t first, int16_t snd);
   int8_t (*namedArgsWildcards)(int32_t _, int16_t named, int64_t _1);
 };

tests/expectations/simplify-option-ptr.c

@@ -8,13 +8,13 @@ typedef struct Opaque Opaque;
 typedef struct {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 } Foo;
 
 typedef union {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 } Bar;
 
 void root(const Opaque *a, Opaque *b, Foo c, Bar d);

tests/expectations/simplify-option-ptr.compat.c

@@ -8,13 +8,13 @@ typedef struct Opaque Opaque;
 typedef struct {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 } Foo;
 
 typedef union {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 } Bar;
 
 #ifdef __cplusplus

tests/expectations/simplify-option-ptr.cpp

@@ -8,13 +8,13 @@ struct Opaque;
 struct Foo {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 };
 
 union Bar {
   const Opaque *x;
   Opaque *y;
-  void (*z)();
+  void (*z)(void);
 };
 
 extern "C" {

tests/expectations/tag/cdecl.c

@@ -3,15 +3,15 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-typedef void (*A)();
+typedef void (*A)(void);
 
-typedef void (*B)();
+typedef void (*B)(void);
 
 typedef bool (*C)(int32_t, int32_t);
 
 typedef bool (*(*D)(int32_t))(float);
 
-typedef const int32_t (*(*E)())[16];
+typedef const int32_t (*(*E)(void))[16];
 
 typedef const int32_t *F;
 

tests/expectations/tag/cdecl.compat.c

@@ -3,15 +3,15 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-typedef void (*A)();
+typedef void (*A)(void);
 
-typedef void (*B)();
+typedef void (*B)(void);
 
 typedef bool (*C)(int32_t, int32_t);
 
 typedef bool (*(*D)(int32_t))(float);
 
-typedef const int32_t (*(*E)())[16];
+typedef const int32_t (*(*E)(void))[16];
 
 typedef const int32_t *F;
 

tests/expectations/tag/fns.c

@@ -4,9 +4,9 @@
 #include <stdlib.h>
 
 struct Fns {
-  void (*noArgs)();
+  void (*noArgs)(void);
   void (*anonymousArg)(int32_t);
-  int32_t (*returnsNumber)();
+  int32_t (*returnsNumber)(void);
   int8_t (*namedArgs)(int32_t first, int16_t snd);
   int8_t (*namedArgsWildcards)(int32_t _, int16_t named, int64_t _1);
 };

tests/expectations/tag/fns.compat.c

@@ -4,9 +4,9 @@
 #include <stdlib.h>
 
 struct Fns {
-  void (*noArgs)();
+  void (*noArgs)(void);
   void (*anonymousArg)(int32_t);
-  int32_t (*returnsNumber)();
+  int32_t (*returnsNumber)(void);
   int8_t (*namedArgs)(int32_t first, int16_t snd);
   int8_t (*namedArgsWildcards)(int32_t _, int16_t named, int64_t _1);
 };

tests/expectations/tag/simplify-option-ptr.c

@@ -8,13 +8,13 @@ struct Opaque;
 struct Foo {
   const struct Opaque *x;
   struct Opaque *y;
-  void (*z)();
+  void (*z)(void);
 };
 
 union Bar {
   const struct Opaque *x;
   struct Opaque *y;
-  void (*z)();
+  void (*z)(void);
 };
 
 void root(const struct Opaque *a, struct Opaque *b, struct Foo c, union Bar d);

tests/expectations/tag/simplify-option-ptr.compat.c

@@ -8,13 +8,13 @@ struct Opaque;
 struct Foo {
   const struct Opaque *x;
   struct Opaque *y;
-  void (*z)();
+  void (*z)(void);
 };
 
 union Bar {
   const struct Opaque *x;
   struct Opaque *y;
-  void (*z)();
+  void (*z)(void);
 };
 
 #ifdef __cplusplus