Fix clang 15 -Wstrict-prototype warnings

Clang 15 has become more strict about prototypes of functions without arguments in C, showing many warnings similar to:

    src/cbor/maps.h:49:49: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
    CBOR_EXPORT cbor_item_t *cbor_new_indefinite_map();
                                                    ^
                                                     void

This is because in C, functions declared or defined with () are considered old-style functions with variadic arguments. (Although these will likely be finally removed in C23.)

Fix the warnings by using `(void)` for each of the declarations and definitions. This also fixes two incorrect invocations of `cbor_new_indefinite_map(void)` in the tests.

examples/bazel/src/hello.h

@@ -3,6 +3,6 @@
 
 #include <cstdint>
 
-uint8_t cbor_version();
+uint8_t cbor_version(void);
 
 #endif  // HELLO_H_

examples/cjson2cbor.c

@@ -110,7 +110,7 @@ void cjson_cbor_stream_decode(cJSON *source,
   }
 }
 
-void usage() {
+void usage(void) {
   printf("Usage: cjson [input JSON file]\n");
   exit(1);
 }

examples/create_items.c

@@ -8,7 +8,7 @@
 #include <stdio.h>
 #include "cbor.h"
 
-int main() {
+int main(void) {
   /* Preallocate the map structure */
   cbor_item_t* root = cbor_new_definite_map(2);
   /* Add the content */

examples/hello.c

@@ -8,7 +8,7 @@
 #include <stdio.h>
 #include "cbor.h"
 
-int main() {
+int main(void) {
   printf("Hello from libcbor %s\n", CBOR_VERSION);
   printf("Custom allocation support: %s\n", CBOR_CUSTOM_ALLOC ? "yes" : "no");
   printf("Pretty-printer support: %s\n", CBOR_PRETTY_PRINTER ? "yes" : "no");

examples/readfile.c

@@ -8,7 +8,7 @@
 #include <stdio.h>
 #include "cbor.h"
 
-void usage() {
+void usage(void) {
   printf("Usage: readfile [input file]\n");
   exit(1);
 }

examples/sort.c

@@ -26,7 +26,7 @@ int compareUint(const void *a, const void *b) {
     return 1;
 }
 
-int main() {
+int main(void) {
   cbor_item_t *array = cbor_new_definite_array(4);
   cbor_array_push(array, cbor_move(cbor_build_uint8(4)));
   cbor_array_push(array, cbor_move(cbor_build_uint8(3)));

examples/streaming_array.c

@@ -8,7 +8,7 @@
 #include <stdlib.h>
 #include "cbor.h"
 
-void usage() {
+void usage(void) {
   printf("Usage: streaming_array <N>\n");
   printf("Prints out serialized array [0, ..., N-1]\n");
   exit(1);

examples/streaming_parser.c

@@ -15,7 +15,7 @@
 #define UNUSED(x) x
 #endif
 
-void usage() {
+void usage(void) {
   printf("Usage: streaming_parser [input file]\n");
   exit(1);
 }

src/cbor/arrays.c

@@ -116,7 +116,7 @@ cbor_item_t *cbor_new_definite_array(size_t size) {
   return item;
 }
 
-cbor_item_t *cbor_new_indefinite_array() {
+cbor_item_t *cbor_new_indefinite_array(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t));
   _CBOR_NOTNULL(item);
 

src/cbor/arrays.h

@@ -97,7 +97,7 @@ CBOR_EXPORT cbor_item_t* cbor_new_definite_array(size_t size);
  *
  * @return **new** array or `NULL` upon malloc failure
  */
-CBOR_EXPORT cbor_item_t* cbor_new_indefinite_array();
+CBOR_EXPORT cbor_item_t* cbor_new_indefinite_array(void);
 
 /** Append to the end
  *

src/cbor/bytestrings.c

@@ -28,7 +28,7 @@ bool cbor_bytestring_is_indefinite(const cbor_item_t *item) {
   return !cbor_bytestring_is_definite(item);
 }
 
-cbor_item_t *cbor_new_definite_bytestring() {
+cbor_item_t *cbor_new_definite_bytestring(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t));
   _CBOR_NOTNULL(item);
   *item = (cbor_item_t){
@@ -39,7 +39,7 @@ cbor_item_t *cbor_new_definite_bytestring() {
   return item;
 }
 
-cbor_item_t *cbor_new_indefinite_bytestring() {
+cbor_item_t *cbor_new_indefinite_bytestring(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t));
   _CBOR_NOTNULL(item);
   *item = (cbor_item_t){

src/cbor/bytestrings.h

@@ -104,15 +104,15 @@ CBOR_EXPORT bool cbor_bytestring_add_chunk(cbor_item_t *item,
  *
  * @return **new** definite bytestring. `NULL` on malloc failure.
  */
-CBOR_EXPORT cbor_item_t *cbor_new_definite_bytestring();
+CBOR_EXPORT cbor_item_t *cbor_new_definite_bytestring(void);
 
 /** Creates a new indefinite byte string
  *
  * The chunks array is initialized to `NULL` and chunk count to 0
  *
  * @return **new** indefinite bytestring. `NULL` on malloc failure.
  */
-CBOR_EXPORT cbor_item_t *cbor_new_indefinite_bytestring();
+CBOR_EXPORT cbor_item_t *cbor_new_indefinite_bytestring(void);
 
 /** Creates a new byte string and initializes it
  *

src/cbor/floats_ctrls.c

@@ -93,7 +93,7 @@ void cbor_set_bool(cbor_item_t *item, bool value) {
       value ? CBOR_CTRL_TRUE : CBOR_CTRL_FALSE;
 }
 
-cbor_item_t *cbor_new_ctrl() {
+cbor_item_t *cbor_new_ctrl(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t));
   _CBOR_NOTNULL(item);
 
@@ -106,7 +106,7 @@ cbor_item_t *cbor_new_ctrl() {
   return item;
 }
 
-cbor_item_t *cbor_new_float2() {
+cbor_item_t *cbor_new_float2(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t) + 4);
   _CBOR_NOTNULL(item);
 
@@ -118,7 +118,7 @@ cbor_item_t *cbor_new_float2() {
   return item;
 }
 
-cbor_item_t *cbor_new_float4() {
+cbor_item_t *cbor_new_float4(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t) + 4);
   _CBOR_NOTNULL(item);
 
@@ -130,7 +130,7 @@ cbor_item_t *cbor_new_float4() {
   return item;
 }
 
-cbor_item_t *cbor_new_float8() {
+cbor_item_t *cbor_new_float8(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t) + 8);
   _CBOR_NOTNULL(item);
 
@@ -142,14 +142,14 @@ cbor_item_t *cbor_new_float8() {
   return item;
 }
 
-cbor_item_t *cbor_new_null() {
+cbor_item_t *cbor_new_null(void) {
   cbor_item_t *item = cbor_new_ctrl();
   _CBOR_NOTNULL(item);
   cbor_set_ctrl(item, CBOR_CTRL_NULL);
   return item;
 }
 
-cbor_item_t *cbor_new_undef() {
+cbor_item_t *cbor_new_undef(void) {
   cbor_item_t *item = cbor_new_ctrl();
   _CBOR_NOTNULL(item);
   cbor_set_ctrl(item, CBOR_CTRL_UNDEF);

src/cbor/floats_ctrls.h

@@ -84,43 +84,43 @@ CBOR_EXPORT bool cbor_get_bool(const cbor_item_t *item);
  *
  * @return **new** 1B ctrl or `NULL` upon memory allocation failure
  */
-CBOR_EXPORT cbor_item_t *cbor_new_ctrl();
+CBOR_EXPORT cbor_item_t *cbor_new_ctrl(void);
 
 /** Constructs a new float item
  *
  * The width cannot be changed once the item is created
  *
  * @return **new** 2B float or `NULL` upon memory allocation failure
  */
-CBOR_EXPORT cbor_item_t *cbor_new_float2();
+CBOR_EXPORT cbor_item_t *cbor_new_float2(void);
 
 /** Constructs a new float item
  *
  * The width cannot be changed once the item is created
  *
  * @return **new** 4B float or `NULL` upon memory allocation failure
  */
-CBOR_EXPORT cbor_item_t *cbor_new_float4();
+CBOR_EXPORT cbor_item_t *cbor_new_float4(void);
 
 /** Constructs a new float item
  *
  * The width cannot be changed once the item is created
  *
  * @return **new** 8B float or `NULL` upon memory allocation failure
  */
-CBOR_EXPORT cbor_item_t *cbor_new_float8();
+CBOR_EXPORT cbor_item_t *cbor_new_float8(void);
 
 /** Constructs new null ctrl item
  *
  * @return **new** null ctrl item or `NULL` upon memory allocation failure
  */
-CBOR_EXPORT cbor_item_t *cbor_new_null();
+CBOR_EXPORT cbor_item_t *cbor_new_null(void);
 
 /** Constructs new undef ctrl item
  *
  * @return **new** undef ctrl item or `NULL` upon memory allocation failure
  */
-CBOR_EXPORT cbor_item_t *cbor_new_undef();
+CBOR_EXPORT cbor_item_t *cbor_new_undef(void);
 
 /** Constructs new boolean ctrl item
  *

src/cbor/internal/stack.c

@@ -7,7 +7,7 @@
 
 #include "stack.h"
 
-struct _cbor_stack _cbor_stack_init() {
+struct _cbor_stack _cbor_stack_init(void) {
   return (struct _cbor_stack){.top = NULL, .size = 0};
 }
 

src/cbor/internal/stack.h

@@ -27,7 +27,7 @@ struct _cbor_stack {
   size_t size;
 };
 
-struct _cbor_stack _cbor_stack_init();
+struct _cbor_stack _cbor_stack_init(void);
 
 void _cbor_stack_pop(struct _cbor_stack *);
 

src/cbor/ints.c

@@ -86,7 +86,7 @@ void cbor_mark_negint(cbor_item_t *item) {
   item->type = CBOR_TYPE_NEGINT;
 }
 
-cbor_item_t *cbor_new_int8() {
+cbor_item_t *cbor_new_int8(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t) + 1);
   _CBOR_NOTNULL(item);
   *item = (cbor_item_t){.data = (unsigned char *)item + sizeof(cbor_item_t),
@@ -96,7 +96,7 @@ cbor_item_t *cbor_new_int8() {
   return item;
 }
 
-cbor_item_t *cbor_new_int16() {
+cbor_item_t *cbor_new_int16(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t) + 2);
   _CBOR_NOTNULL(item);
   *item = (cbor_item_t){.data = (unsigned char *)item + sizeof(cbor_item_t),
@@ -106,7 +106,7 @@ cbor_item_t *cbor_new_int16() {
   return item;
 }
 
-cbor_item_t *cbor_new_int32() {
+cbor_item_t *cbor_new_int32(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t) + 4);
   _CBOR_NOTNULL(item);
   *item = (cbor_item_t){.data = (unsigned char *)item + sizeof(cbor_item_t),
@@ -116,7 +116,7 @@ cbor_item_t *cbor_new_int32() {
   return item;
 }
 
-cbor_item_t *cbor_new_int64() {
+cbor_item_t *cbor_new_int64(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t) + 8);
   _CBOR_NOTNULL(item);
   *item = (cbor_item_t){.data = (unsigned char *)item + sizeof(cbor_item_t),

src/cbor/ints.h

@@ -118,7 +118,7 @@ CBOR_EXPORT void cbor_mark_negint(cbor_item_t *item);
  * @return **new** positive integer or `NULL` on memory allocation failure. The
  * value is not initialized
  */
-CBOR_EXPORT cbor_item_t *cbor_new_int8();
+CBOR_EXPORT cbor_item_t *cbor_new_int8(void);
 
 /** Allocates new integer with 2B width
  *
@@ -127,7 +127,7 @@ CBOR_EXPORT cbor_item_t *cbor_new_int8();
  * @return **new** positive integer or `NULL` on memory allocation failure. The
  * value is not initialized
  */
-CBOR_EXPORT cbor_item_t *cbor_new_int16();
+CBOR_EXPORT cbor_item_t *cbor_new_int16(void);
 
 /** Allocates new integer with 4B width
  *
@@ -136,7 +136,7 @@ CBOR_EXPORT cbor_item_t *cbor_new_int16();
  * @return **new** positive integer or `NULL` on memory allocation failure. The
  * value is not initialized
  */
-CBOR_EXPORT cbor_item_t *cbor_new_int32();
+CBOR_EXPORT cbor_item_t *cbor_new_int32(void);
 
 /** Allocates new integer with 8B width
  *
@@ -145,7 +145,7 @@ CBOR_EXPORT cbor_item_t *cbor_new_int32();
  * @return **new** positive integer or `NULL` on memory allocation failure. The
  * value is not initialized
  */
-CBOR_EXPORT cbor_item_t *cbor_new_int64();
+CBOR_EXPORT cbor_item_t *cbor_new_int64(void);
 
 /** Constructs a new positive integer
  *

src/cbor/maps.c

@@ -34,7 +34,7 @@ cbor_item_t *cbor_new_definite_map(size_t size) {
   return item;
 }
 
-cbor_item_t *cbor_new_indefinite_map() {
+cbor_item_t *cbor_new_indefinite_map(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t));
   _CBOR_NOTNULL(item);
 

src/cbor/maps.h

@@ -46,7 +46,7 @@ CBOR_EXPORT cbor_item_t *cbor_new_definite_map(size_t size);
  *
  * @return **new** indefinite map. `NULL` on malloc failure.
  */
-CBOR_EXPORT cbor_item_t *cbor_new_indefinite_map();
+CBOR_EXPORT cbor_item_t *cbor_new_indefinite_map(void);
 
 /** Add a pair to the map
  *

src/cbor/strings.c

@@ -9,7 +9,7 @@
 #include <string.h>
 #include "internal/memory_utils.h"
 
-cbor_item_t *cbor_new_definite_string() {
+cbor_item_t *cbor_new_definite_string(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t));
   _CBOR_NOTNULL(item);
   *item = (cbor_item_t){
@@ -19,7 +19,7 @@ cbor_item_t *cbor_new_definite_string() {
   return item;
 }
 
-cbor_item_t *cbor_new_indefinite_string() {
+cbor_item_t *cbor_new_indefinite_string(void) {
   cbor_item_t *item = _CBOR_MALLOC(sizeof(cbor_item_t));
   _CBOR_NOTNULL(item);
   *item = (cbor_item_t){

src/cbor/strings.h

@@ -118,15 +118,15 @@ CBOR_EXPORT bool cbor_string_add_chunk(cbor_item_t *item, cbor_item_t *chunk);
  *
  * @return **new** definite string. `NULL` on malloc failure.
  */
-CBOR_EXPORT cbor_item_t *cbor_new_definite_string();
+CBOR_EXPORT cbor_item_t *cbor_new_definite_string(void);
 
 /** Creates a new indefinite string
  *
  * The chunks array is initialized to `NULL` and chunkcount to 0
  *
  * @return **new** indefinite string. `NULL` on malloc failure.
  */
-CBOR_EXPORT cbor_item_t *cbor_new_indefinite_string();
+CBOR_EXPORT cbor_item_t *cbor_new_indefinite_string(void);
 
 /** Creates a new string and initializes it
  *

test/cbor_serialize_test.c

@@ -207,7 +207,7 @@ static void test_serialize_definite_map(void **_CBOR_UNUSED(_state)) {
 }
 
 static void test_serialize_indefinite_map(void **_CBOR_UNUSED(_state)) {
-  cbor_item_t *item = cbor_new_indefinite_map(2);
+  cbor_item_t *item = cbor_new_indefinite_map();
   cbor_item_t *one = cbor_build_uint8(1);
   cbor_item_t *two = cbor_build_uint8(2);
 

test/copy_test.c

@@ -139,7 +139,7 @@ static void test_def_map(void **_CBOR_UNUSED(_state)) {
 }
 
 static void test_indef_map(void **_CBOR_UNUSED(_state)) {
-  item = cbor_new_indefinite_map(1);
+  item = cbor_new_indefinite_map();
   cbor_map_add(item, (struct cbor_pair){
                          .key = cbor_move(cbor_build_uint8(42)),
                          .value = cbor_move(cbor_build_uint8(43)),

test/float_ctrl_encoders_test.c

@@ -40,7 +40,7 @@ static void test_break(void **_CBOR_UNUSED(_state)) {
 
 /* Check that encode(decode(buffer)) = buffer for a valid half-float in the
  * buffer.*/
-static void assert_half_float_codec_identity() {
+static void assert_half_float_codec_identity(void) {
   unsigned char secondary_buffer[3];
   struct cbor_load_result res;
   // Load and check data in buffer