Fixing -Wstrict-prototypes warnings.

Bug: webrtc:8984
Change-Id: I9a7ffb0038f341bfec055f021fc203c7d45d72fa
Reviewed-on: https://webrtc-review.googlesource.com/60903
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22501}

BUILD.gn

@@ -171,7 +171,9 @@ config("common_inherited_config") {
 
 config("common_config") {
   cflags = []
+  cflags_c = []
   cflags_cc = []
+  cflags_objc = []
   defines = []
 
   if (rtc_enable_protobuf) {
@@ -221,6 +223,20 @@ config("common_config") {
         "-Wno-missing-field-initializers",
         "-Wno-strict-overflow",
       ]
+      cflags_c += [
+        # TODO(bugs.webrtc.org/9029): enable commented compiler flags.
+        # Some of these flags should also be added to cflags_objc.
+
+        # "-Wextra",  (used when building C++ but not when building C)
+        # "-Wmissing-prototypes",  (C/Obj-C only)
+        # "-Wmissing-declarations",  (ensure this is always used C/C++, etc..)
+        "-Wstrict-prototypes",
+
+        # "-Wpointer-arith",  (ensure this is always used C/C++, etc..)
+        # "-Wbad-function-cast",  (C/Obj-C only)
+        # "-Wnested-externs",  (C/Obj-C only)
+      ]
+      cflags_objc += [ "-Wstrict-prototypes" ]
       cflags_cc = [
         "-Wnon-virtual-dtor",
 

common_audio/signal_processing/include/signal_processing_library.h

@@ -110,7 +110,7 @@ extern "C" {
 // C code will be assigned.
 // Note that this function MUST be called in any application that uses SPL
 // functions.
-void WebRtcSpl_Init();
+void WebRtcSpl_Init(void);
 
 int16_t WebRtcSpl_GetScalingSquare(int16_t* in_vector,
                                    size_t in_vector_length,

common_audio/signal_processing/spl_init.c

@@ -30,7 +30,7 @@ ScaleAndAddVectorsWithRound WebRtcSpl_ScaleAndAddVectorsWithRound;
 
 #if (!defined(WEBRTC_HAS_NEON)) && !defined(MIPS32_LE)
 /* Initialize function pointers to the generic C version. */
-static void InitPointersToC() {
+static void InitPointersToC(void) {
   WebRtcSpl_MaxAbsValueW16 = WebRtcSpl_MaxAbsValueW16C;
   WebRtcSpl_MaxAbsValueW32 = WebRtcSpl_MaxAbsValueW32C;
   WebRtcSpl_MaxValueW16 = WebRtcSpl_MaxValueW16C;
@@ -46,7 +46,7 @@ static void InitPointersToC() {
 
 #if defined(WEBRTC_HAS_NEON)
 /* Initialize function pointers to the Neon version. */
-static void InitPointersToNeon() {
+static void InitPointersToNeon(void) {
   WebRtcSpl_MaxAbsValueW16 = WebRtcSpl_MaxAbsValueW16Neon;
   WebRtcSpl_MaxAbsValueW32 = WebRtcSpl_MaxAbsValueW32Neon;
   WebRtcSpl_MaxValueW16 = WebRtcSpl_MaxValueW16Neon;
@@ -62,7 +62,7 @@ static void InitPointersToNeon() {
 
 #if defined(MIPS32_LE)
 /* Initialize function pointers to the MIPS version. */
-static void InitPointersToMIPS() {
+static void InitPointersToMIPS(void) {
   WebRtcSpl_MaxAbsValueW16 = WebRtcSpl_MaxAbsValueW16_mips;
   WebRtcSpl_MaxValueW16 = WebRtcSpl_MaxValueW16_mips;
   WebRtcSpl_MaxValueW32 = WebRtcSpl_MaxValueW32_mips;
@@ -128,6 +128,6 @@ static void once(void (*func)(void)) {
  */
 #endif  /* WEBRTC_POSIX */
 
-void WebRtcSpl_Init() {
+void WebRtcSpl_Init(void) {
   once(InitFunctionPointers);
 }

common_audio/vad/include/webrtc_vad.h

@@ -27,7 +27,7 @@ extern "C" {
 #endif
 
 // Creates an instance to the VAD structure.
-VadInst* WebRtcVad_Create();
+VadInst* WebRtcVad_Create(void);
 
 // Frees the dynamic memory of a specified VAD instance.
 //

examples/objc/AppRTCMobile/common/ARDUtilities.h

@@ -34,5 +34,5 @@
 
 @end
 
-NSInteger ARDGetCpuUsagePercentage();
+NSInteger ARDGetCpuUsagePercentage(void);
 

modules/audio_coding/codecs/isac/fix/source/codec.h

@@ -67,7 +67,7 @@ void WebRtcIsacfix_InitPlc(PLCstr* State);
 
 /* transform functions */
 
-void WebRtcIsacfix_InitTransform();
+void WebRtcIsacfix_InitTransform(void);
 
 typedef void (*Time2Spec)(int16_t* inre1Q9,
                           int16_t* inre2Q9,

modules/audio_processing/agc/legacy/gain_control.h

@@ -208,7 +208,7 @@ int WebRtcAgc_get_config(void* agcInst, WebRtcAgcConfig* config);
  * This function creates and returns an AGC instance, which will contain the
  * state information for one (duplex) channel.
  */
-void* WebRtcAgc_Create();
+void* WebRtcAgc_Create(void);
 
 /*
  * This function frees the AGC instance created at the beginning.

modules/audio_processing/ns/noise_suppression.h

@@ -24,7 +24,7 @@ extern "C" {
 /*
  * This function creates an instance of the floating point Noise Suppression.
  */
-NsHandle* WebRtcNs_Create();
+NsHandle* WebRtcNs_Create(void);
 
 /*
  * This function frees the dynamic memory of a specified noise suppression
@@ -126,7 +126,7 @@ const float* WebRtcNs_noise_estimate(const NsHandle* handle);
  *
  * Return value         : Number of frequency bins.
  */
-size_t WebRtcNs_num_freq();
+size_t WebRtcNs_num_freq(void);
 
 #ifdef __cplusplus
 }

modules/audio_processing/ns/noise_suppression_x.h

@@ -24,7 +24,7 @@ extern "C" {
 /*
  * This function creates an instance of the fixed point Noise Suppression.
  */
-NsxHandle* WebRtcNsx_Create();
+NsxHandle* WebRtcNsx_Create(void);
 
 /*
  * This function frees the dynamic memory of a specified Noise Suppression
@@ -104,7 +104,7 @@ const uint32_t* WebRtcNsx_noise_estimate(const NsxHandle* nsxInst,
  *
  * Return value         : Number of frequency bins.
  */
-size_t WebRtcNsx_num_freq();
+size_t WebRtcNsx_num_freq(void);
 
 #ifdef __cplusplus
 }