unnecessary compilation noise

[fabiangreffrath]

Hi there,

could we please get rid of this message - or at least only show it if not explicitly built with miniz as the zlib API provider?

Thanks!

libspng/spng/spng.c

Line 1212 in adc9439

#pragma message ("inflateValidate() not available, SPNG_CTX_IGNORE_ADLER32 will be ignored")

[randy408]

AFAIK it shows up not just with miniz but also for very old and insecure zlib versions, I wouldn't call that unnecessary.

It has to be a compile-time message, the function that takes SPNG_CTX_IGNORE_ADLER32 does not return an error code, it is the only way to know that feature will not work. Making it a build system message wouldn't really work either because compiling the library without the included build files is explicitly supported.

[fabiangreffrath]

AFAIK it shows up not just with miniz but also for very old and insecure zlib versions, I wouldn't call that unnecessary.

I see. My point is that if I explicitly build with -DSPNG_USE_MINIZ then I'm already aware of the fact that I'm building with a reduced/minimal zlib API implementation and I don't need to be remembered every time I rebuild my project.

My idea is something like this:

--- a/spng/spng.c
+++ b/spng/spng.c
@@ -1208,7 +1208,7 @@ static int spng__inflate_init(spng_ctx *ctx, int window_bits)
 
     if(inflateValidate(&ctx->zstream, validate)) return SPNG_EZLIB_INIT;
 
-#else /* This requires zlib >= 1.2.11 */
+#else if !defined(SPNG_USE_MINIZ) /* This requires zlib >= 1.2.11 */
     #pragma message ("inflateValidate() not available, SPNG_CTX_IGNORE_ADLER32 will be ignored")
 #endif
 

But, of course, it's your choice in the end. I could understand if you just said "no" and close this issue. 😉