Re: macos ventura SDK spews warnings - Mailing list pgsql-hackers

I wrote:
> Andres Freund <andres@anarazel.de> writes:
>> [24/2258] Compiling C object src/port/libpgport_srv.a.p/snprintf.c.o
>> ../../../src/postgres/src/port/snprintf.c:1002:11: warning: 'sprintf' is deprecated: This function is provided for
compatibilityreasons only.  Due to security concerns inherent in the design of sprintf(3), it is highly recommended
thatyou use snprintf(3) instead. [-Wdeprecated-declarations] 

> Originally we used the platform's sprintf there because we couldn't
> rely on platforms having functional snprintf.  That's no longer the case,
> I imagine, so we could just switch these calls over to snprintf.  I'm
> kind of surprised that we haven't already been getting the likes of
> this warning from, eg, OpenBSD.

The attached seems enough to silence it for me.

Should we back-patch this?  I suppose, but how far?  It seems to fall
under the rules we established for back-patching into out-of-support
branches, ie it silences compiler warnings but shouldn't change any
behavior.  But it feels like a bigger change than most of the other
things we've done that with.

            regards, tom lane

diff --git a/src/port/snprintf.c b/src/port/snprintf.c
index e037cf0a88..81d9c8c274 100644
--- a/src/port/snprintf.c
+++ b/src/port/snprintf.c
@@ -998,8 +998,8 @@ fmtptr(const void *value, PrintfTarget *target)
     int            vallen;
     char        convert[64];

-    /* we rely on regular C library's sprintf to do the basic conversion */
-    vallen = sprintf(convert, "%p", value);
+    /* we rely on regular C library's snprintf to do the basic conversion */
+    vallen = snprintf(convert, sizeof(convert), "%p", value);
     if (vallen < 0)
         target->failed = true;
     else
@@ -1149,11 +1149,11 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
     int            padlen;            /* amount to pad with spaces */

     /*
-     * We rely on the regular C library's sprintf to do the basic conversion,
+     * We rely on the regular C library's snprintf to do the basic conversion,
      * then handle padding considerations here.
      *
      * The dynamic range of "double" is about 1E+-308 for IEEE math, and not
-     * too wildly more than that with other hardware.  In "f" format, sprintf
+     * too wildly more than that with other hardware.  In "f" format, snprintf
      * could therefore generate at most 308 characters to the left of the
      * decimal point; while we need to allow the precision to get as high as
      * 308+17 to ensure that we don't truncate significant digits from very
@@ -1205,14 +1205,14 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
             fmt[2] = '*';
             fmt[3] = type;
             fmt[4] = '\0';
-            vallen = sprintf(convert, fmt, prec, value);
+            vallen = snprintf(convert, sizeof(convert), fmt, prec, value);
         }
         else
         {
             fmt[0] = '%';
             fmt[1] = type;
             fmt[2] = '\0';
-            vallen = sprintf(convert, fmt, value);
+            vallen = snprintf(convert, sizeof(convert), fmt, value);
         }
         if (vallen < 0)
             goto fail;
@@ -1341,7 +1341,7 @@ pg_strfromd(char *str, size_t count, int precision, double value)
             fmt[2] = '*';
             fmt[3] = 'g';
             fmt[4] = '\0';
-            vallen = sprintf(convert, fmt, precision, value);
+            vallen = snprintf(convert, sizeof(convert), fmt, precision, value);
             if (vallen < 0)
             {
                 target.failed = true;