stbi: make static

not to spoil the global namespace

+ since some functions are not used, it may also save a few bytes in build
+ revert warning fixes in stbi_image.h in the commit df3330d since
no longer needed - vanilla version is used now

Author: MartinPulec

src/utils/image_delegate.c

@@ -46,14 +46,24 @@
 #define strtok_s strtok_r
 #endif
 
+
 #include "../gpujpeg_common_internal.h"
 #include "../../libgpujpeg/gpujpeg_decoder.h" // ddecoder placeholders
 #include "image_delegate.h"
 #include "pam.h"
-#define STB_IMAGE_WRITE_IMPLEMENTATION
-#include "stb_image_write.h"
 #include "y4m.h"
 
+enum {
+  DEPTH_8B = 8,
+  MAXVAL_8B = 255,
+};
+
+// stbi_image and stbi_image_write include
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 static void
 gpujpeg_cuda_free_host(void* ptr);
 static void*
@@ -68,12 +78,16 @@ gpujpeg_cuda_realloc_sized_host(void* ptr, int oldsz, int newsz);
 #define STBI_FREE gpujpeg_cuda_free_host
 #define STBI_REALLOC_SIZED gpujpeg_cuda_realloc_sized_host
 #define STB_IMAGE_IMPLEMENTATION
+#define STB_IMAGE_STATIC
 #include "stb_image.h"
 
-enum {
-  DEPTH_8B = 8,
-  MAXVAL_8B = 255,
-};
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#define STB_IMAGE_WRITE_STATIC
+#include "stb_image_write.h"
+
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
 
 static void
 gpujpeg_cuda_free_host(void* ptr)

src/utils/stb_image.h

@@ -1066,7 +1066,6 @@ static void *stbi__malloc_mad4(int a, int b, int c, int d, int add)
 }
 #endif
 
-#ifndef STBI_NO_JPEG
 // returns 1 if the sum of two signed ints is valid (between -2^31 and 2^31-1 inclusive), 0 on overflow.
 static int stbi__addints_valid(int a, int b)
 {
@@ -1083,7 +1082,6 @@ static int stbi__mul2shorts_valid(int a, int b)
    if (b < 0) return a <= SHRT_MIN / b; // same as a * b >= SHRT_MIN
    return a >= SHRT_MIN / b;
 }
-#endif
 
 // stbi__err - error
 // stbi__errpf - error returning pointer to float
@@ -7675,7 +7673,6 @@ static int stbi__info_main(stbi__context *s, int *x, int *y, int *comp)
 
 static int stbi__is_16_main(stbi__context *s)
 {
-   (void) s;
    #ifndef STBI_NO_PNG
    if (stbi__png_is16(s))  return 1;
    #endif