From 25a614bc3e573909b5801d3d21c4af46e5f7fa51 Mon Sep 17 00:00:00 2001
From: Cameron Cawley <ccawley2011@gmail.com>
Date: Tue, 14 Sep 2021 20:37:35 +0100
Subject: [PATCH] Add SDL_asprintf and SDL_vasprintf

---
 include/SDL_stdinc.h              |  2 ++
 src/dynapi/SDL_dynapi.c           |  6 ++++
 src/dynapi/SDL_dynapi_overrides.h |  2 ++
 src/dynapi/SDL_dynapi_procs.h     |  4 +++
 src/stdlib/SDL_string.c           | 56 +++++++++++++++++++++++++++++++
 5 files changed, 70 insertions(+)

diff --git a/include/SDL_stdinc.h b/include/SDL_stdinc.h
index f66f4eab7..17edc8511 100644
--- a/include/SDL_stdinc.h
+++ b/include/SDL_stdinc.h
@@ -566,6 +566,8 @@ extern DECLSPEC int SDLCALL SDL_sscanf(const char *text, SDL_SCANF_FORMAT_STRING
 extern DECLSPEC int SDLCALL SDL_vsscanf(const char *text, const char *fmt, va_list ap);
 extern DECLSPEC int SDLCALL SDL_snprintf(SDL_OUT_Z_CAP(maxlen) char *text, size_t maxlen, SDL_PRINTF_FORMAT_STRING const char *fmt, ... ) SDL_PRINTF_VARARG_FUNC(3);
 extern DECLSPEC int SDLCALL SDL_vsnprintf(SDL_OUT_Z_CAP(maxlen) char *text, size_t maxlen, const char *fmt, va_list ap);
+extern DECLSPEC int SDLCALL SDL_asprintf(char **strp, SDL_PRINTF_FORMAT_STRING const char *fmt, ...) SDL_PRINTF_VARARG_FUNC(2);
+extern DECLSPEC int SDLCALL SDL_vasprintf(char **strp, const char *fmt, va_list ap);
 
 #ifndef HAVE_M_PI
 #ifndef M_PI
diff --git a/src/dynapi/SDL_dynapi.c b/src/dynapi/SDL_dynapi.c
index 013dbc90d..4dc16b126 100644
--- a/src/dynapi/SDL_dynapi.c
+++ b/src/dynapi/SDL_dynapi.c
@@ -89,6 +89,12 @@ static void SDL_InitDynamicAPI(void);
         va_end(ap); \
         return retval; \
     } \
+    _static int SDLCALL SDL_asprintf##name(char **strp, SDL_PRINTF_FORMAT_STRING const char *fmt, ...) { \
+        int retval; va_list ap; initcall; va_start(ap, fmt); \
+        retval = jump_table.SDL_vasprintf(strp, fmt, ap); \
+        va_end(ap); \
+        return retval; \
+    } \
     _static void SDLCALL SDL_Log##name(SDL_PRINTF_FORMAT_STRING const char *fmt, ...) { \
         va_list ap; initcall; va_start(ap, fmt); \
         jump_table.SDL_LogMessageV(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, fmt, ap); \
diff --git a/src/dynapi/SDL_dynapi_overrides.h b/src/dynapi/SDL_dynapi_overrides.h
index b28b5b8d1..77f434729 100644
--- a/src/dynapi/SDL_dynapi_overrides.h
+++ b/src/dynapi/SDL_dynapi_overrides.h
@@ -820,3 +820,5 @@
 #define SDL_RenderGeometry SDL_RenderGeometry_REAL
 #define SDL_RenderGeometryRaw SDL_RenderGeometryRaw_REAL
 #define SDL_RenderSetVSync SDL_RenderSetVSync_REAL
+#define SDL_asprintf SDL_asprintf_REAL
+#define SDL_vasprintf SDL_vasprintf_REAL
diff --git a/src/dynapi/SDL_dynapi_procs.h b/src/dynapi/SDL_dynapi_procs.h
index 9887e623c..c383ea675 100644
--- a/src/dynapi/SDL_dynapi_procs.h
+++ b/src/dynapi/SDL_dynapi_procs.h
@@ -885,3 +885,7 @@ SDL_DYNAPI_PROC(void*,SDL_GetTextureUserData,(SDL_Texture *a),(a),return)
 SDL_DYNAPI_PROC(int,SDL_RenderGeometry,(SDL_Renderer *a, SDL_Texture *b, const SDL_Vertex *c, int d, const int *e, int f),(a,b,c,d,e,f),return)
 SDL_DYNAPI_PROC(int,SDL_RenderGeometryRaw,(SDL_Renderer *a, SDL_Texture *b, const float *c, int d, const int *e, int f, const float *g, int h, int i, const void *j, int k, int l),(a,b,c,d,e,f,g,h,i,j,k,l),return)
 SDL_DYNAPI_PROC(int,SDL_RenderSetVSync,(SDL_Renderer *a, int b),(a,b),return)
+#if !SDL_DYNAPI_PROC_NO_VARARGS
+SDL_DYNAPI_PROC(int,SDL_asprintf,(char **a, SDL_PRINTF_FORMAT_STRING const char *b, ...),(a,b),return)
+#endif
+SDL_DYNAPI_PROC(int,SDL_vasprintf,(char **a, const char *b, va_list c),(a,b,c),return)
diff --git a/src/stdlib/SDL_string.c b/src/stdlib/SDL_string.c
index 76005e204..cb0b84660 100644
--- a/src/stdlib/SDL_string.c
+++ b/src/stdlib/SDL_string.c
@@ -1911,4 +1911,60 @@ SDL_vsnprintf(SDL_OUT_Z_CAP(maxlen) char *text, size_t maxlen, const char *fmt,
 #undef TEXT_AND_LEN_ARGS
 #endif /* HAVE_VSNPRINTF */
 
+int
+SDL_asprintf(char **strp, SDL_PRINTF_FORMAT_STRING const char *fmt, ...)
+{
+    va_list ap;
+    int retval;
+
+    va_start(ap, fmt);
+    retval = SDL_vasprintf(strp, fmt, ap);
+    va_end(ap);
+
+    return retval;
+}
+
+int
+SDL_vasprintf(char **strp, const char *fmt, va_list ap)
+{
+    int retval;
+    int size = 100;     /* Guess we need no more than 100 bytes */
+    char *p, *np;
+    va_list aq;
+
+    *strp = NULL;
+
+    p = (char *)SDL_malloc(size);
+    if (p == NULL)
+        return -1;
+
+    while (1) {
+        /* Try to print in the allocated space */
+        va_copy(aq, ap);
+        retval = SDL_vsnprintf(p, size, fmt, aq);
+        va_end(aq);
+
+        /* Check error code */
+        if (retval < 0)
+            return retval;
+
+        /* If that worked, return the string */
+        if (retval < size) {
+            *strp = p;
+            return retval;
+        }
+
+        /* Else try again with more space */
+        size = retval + 1;       /* Precisely what is needed */
+
+        np = (char *)SDL_realloc(p, size);
+        if (np == NULL) {
+            SDL_free(p);
+            return -1;
+        } else {
+            p = np;
+        }
+    }
+}
+
 /* vi: set ts=4 sw=4 expandtab: */