[libpng16] Conditionally compile some unused functions reported by -Wall

in pngminim.

ANNOUNCE

@@ -33,6 +33,7 @@ Version 1.6.8beta01 [November 19, 2013]
   Moved prototype for png_handle_unknown() in pngpriv.h outside of
     the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
   Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
+  Conditionally compile some unused functions reported by -Wall in pngminim.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -4717,6 +4717,7 @@ Version 1.6.8beta01 [November 19, 2013]
   Moved prototype for png_handle_unknown() in pngpriv.h outside of
     the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
   Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
+  Conditionally compile some unused functions reported by -Wall in pngminim.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

png.c

@@ -768,13 +768,13 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.6.8beta01 - November 14, 2013" PNG_STRING_NEWLINE \
+     "libpng version 1.6.8beta01 - November 19, 2013" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2013 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE;
 #  else
-      return "libpng version 1.6.8beta01 - November 14, 2013\
+      return "libpng version 1.6.8beta01 - November 19, 2013\
       Copyright (c) 1998-2013 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -3268,6 +3268,7 @@ png_gamma_significant(png_fixed_point gamma_val)
 #endif
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
+#  ifdef PNG_16BIT_SUPPORTED
 /* A local convenience routine. */
 static png_fixed_point
 png_product2(png_fixed_point a, png_fixed_point b)
@@ -3289,6 +3290,7 @@ png_product2(png_fixed_point a, png_fixed_point b)
 
    return 0; /* overflow */
 }
+#  endif /* 16BIT */
 
 /* The inverse of the above. */
 png_fixed_point
@@ -3593,6 +3595,7 @@ png_exp8bit(png_fixed_point lg2)
    return (png_byte)((x + 0x7fffffU) >> 24);
 }
 
+#ifdef PNG_16BIT_SUPPORTED
 static png_uint_16
 png_exp16bit(png_fixed_point lg2)
 {
@@ -3603,6 +3606,7 @@ png_exp16bit(png_fixed_point lg2)
    x -= x >> 16;
    return (png_uint_16)((x + 32767U) >> 16);
 }
+#endif /* 16BIT */
 #endif /* FLOATING_ARITHMETIC */
 
 png_byte
@@ -3628,6 +3632,7 @@ png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val)
    return (png_byte)value;
 }
 
+#ifdef PNG_16BIT_SUPPORTED
 png_uint_16
 png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
 {
@@ -3650,6 +3655,7 @@ png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
 
    return (png_uint_16)value;
 }
+#endif /* 16BIT */
 
 /* This does the right thing based on the bit_depth field of the
  * png_struct, interpreting values as 8-bit or 16-bit.  While the result
@@ -3663,10 +3669,16 @@ png_gamma_correct(png_structrp png_ptr, unsigned int value,
    if (png_ptr->bit_depth == 8)
       return png_gamma_8bit_correct(value, gamma_val);
 
+#ifdef PNG_16BIT_SUPPORTED
    else
       return png_gamma_16bit_correct(value, gamma_val);
+#else
+      /* should not reach this */
+      return 0;
+#endif /* 16BIT */
 }
 
+#ifdef PNG_16BIT_SUPPORTED
 /* Internal function to build a single 16-bit table - the table consists of
  * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount
  * to shift the input values right (or 16-number_of_signifiant_bits).
@@ -3805,6 +3817,7 @@ png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable,
       last++;
    }
 }
+#endif /* 16BIT */
 
 /* Build a single 8-bit table: same as the 16-bit case but much simpler (and
  * typically much faster).  Note that libpng currently does no sBIT processing
@@ -3833,6 +3846,7 @@ png_destroy_gamma_table(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->gamma_table);
    png_ptr->gamma_table = NULL;
 
+#ifdef PNG_16BIT_SUPPORTED
    if (png_ptr->gamma_16_table != NULL)
    {
       int i;
@@ -3844,6 +3858,7 @@ png_destroy_gamma_table(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->gamma_16_table);
    png_ptr->gamma_16_table = NULL;
    }
+#endif /* 16BIT */
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
    defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
@@ -3853,6 +3868,7 @@ png_destroy_gamma_table(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->gamma_to_1);
    png_ptr->gamma_to_1 = NULL;
 
+#ifdef PNG_16BIT_SUPPORTED
    if (png_ptr->gamma_16_from_1 != NULL)
    {
       int i;
@@ -3875,6 +3891,7 @@ png_destroy_gamma_table(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->gamma_16_to_1);
    png_ptr->gamma_16_to_1 = NULL;
    }
+#endif /* 16BIT */
 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
 }
 
@@ -3920,6 +3937,7 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
      }
 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
   }
+#ifdef PNG_16BIT_SUPPORTED
   else
   {
      png_byte shift, sig_bit;
@@ -3976,24 +3994,20 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
 
      png_ptr->gamma_shift = shift;
 
-#ifdef PNG_16BIT_SUPPORTED
      /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
       * PNG_COMPOSE).  This effectively smashed the background calculation for
       * 16-bit output because the 8-bit table assumes the result will be reduced
       * to 8 bits.
       */
      if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8))
-#endif
          png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
          png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma,
          png_ptr->screen_gamma) : PNG_FP_1);
 
-#ifdef PNG_16BIT_SUPPORTED
      else
          png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift,
          png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
          png_ptr->screen_gamma) : PNG_FP_1);
-#endif
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
    defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
@@ -4013,6 +4027,7 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
      }
 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
   }
+#endif /* 16BIT */
 }
 #endif /* READ_GAMMA */
 

pngrutil.c

@@ -278,6 +278,10 @@ png_crc_error(png_structrp png_ptr)
       return (0);
 }
 
+#if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\
+    defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\
+    defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\
+    defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED)
 /* Manage the read buffer; this simply reallocates the buffer if it is not small
  * enough (or if it is not allocated).  The routine returns a pointer to the
  * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
@@ -325,6 +329,7 @@ png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
 
    return buffer;
 }
+#endif /* PNG_READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|SEQUENTIAL_READ */
 
 /* png_inflate_claim: claim the zstream for some nefarious purpose that involves
  * decompression.  Returns Z_OK on success, else a zlib error code.  It checks