CMake: allow to replace native *printf to stb_*printf

src/util/FFstrbuf.c

@@ -20,8 +20,15 @@ void ffStrbufInitVF(FFstrbuf* strbuf, const char* format, va_list arguments)
 {
     assert(format != NULL);
 
+    #ifndef FF_USE_STBPRINTF
     int len = vasprintf(&strbuf->chars, format, arguments);
     assert(len >= 0);
+    #else
+    int len = vsnprintf(NULL, 0, format, arguments);
+    assert(len >= 0);
+    strbuf->chars = (char*) malloc(sizeof(char) * (len + 1));
+    vsnprintf(strbuf->chars, len + 1, format, arguments);
+    #endif
 
     strbuf->allocated = (uint32_t)(len + 1);
     strbuf->length = (uint32_t)len;

src/util/FFstrbuf.h

@@ -18,6 +18,8 @@
 
 #define FASTFETCH_STRBUF_DEFAULT_ALLOC 32
 
+#include "stb_printf.h"
+
 typedef struct FFstrbuf
 {
     uint32_t allocated;

src/util/stb_printf.c

@@ -0,0 +1,3 @@
+#define STB_SPRINTF_IMPLEMENTATION 1
+#pragma GCC diagnostic ignored "-Wsign-conversion"
+#include "3rdparty/stb/stb_sprintf.h"

src/util/stb_printf.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#ifdef FF_USE_STBPRINTF
+
+#include <stdio.h>
+#include <stdint.h>
+#include "3rdparty/stb/stb_sprintf.h"
+
+static inline char *STB_SPRINTF_DECORATE(printf_callback)(const char* __restrict buf, void* __restrict user, int len)
+{
+    fwrite(buf, 1, (uint32_t) len, (FILE *)user);
+    return (char *) buf;
+}
+
+static inline int STB_SPRINTF_DECORATE(vfprintf)(FILE* file, char const* __restrict fmt, va_list va)
+{
+    char tmp[STB_SPRINTF_MIN];
+    return STB_SPRINTF_DECORATE(vsprintfcb)(STB_SPRINTF_DECORATE(printf_callback), file, tmp, fmt, va);
+}
+#define vfprintf(...) STB_SPRINTF_DECORATE(vfprintf)(__VA_ARGS__)
+
+static inline int STBSP__ATTRIBUTE_FORMAT(1,2) STB_SPRINTF_DECORATE(printf)(char const* __restrict fmt, ...)
+{
+    va_list va;
+    va_start(va, fmt);
+    int result = STB_SPRINTF_DECORATE(vfprintf)(stdout, fmt, va);
+    va_end(va);
+    return result;
+}
+#define printf(...) STB_SPRINTF_DECORATE(printf)(__VA_ARGS__)
+
+static inline int STBSP__ATTRIBUTE_FORMAT(2,3) STB_SPRINTF_DECORATE(fprintf)(FILE* __restrict file, char const* __restrict fmt, ...)
+{
+    va_list va;
+    va_start(va, fmt);
+    int result = STB_SPRINTF_DECORATE(vfprintf)(file, fmt, va);
+    va_end(va);
+    return result;
+}
+#define fprintf(...) STB_SPRINTF_DECORATE(fprintf)(__VA_ARGS__)
+
+#define vsprintf(...) STB_SPRINTF_DECORATE(vsprintf)(__VA_ARGS__)
+
+#define vsnprintf(...) STB_SPRINTF_DECORATE(vsnprintf)(__VA_ARGS__)
+
+#define sprintf(...) STB_SPRINTF_DECORATE(sprintf)(__VA_ARGS__)
+
+#define snprintf(...) STB_SPRINTF_DECORATE(snprintf)(__VA_ARGS__)
+
+#endif