chore: Fix a typo in Makefile.am; rerun ./autogen.sh --maintainer

Apply the following updates:
 * Tidy up the compiler flag definitions.
 * Update the Darwin, Linux and MSYS makefiles to match the compiler
   flags used in scripts/makefile.clang and scripts/makefile.gcc.
 * Add the `pngtest-static` target in the Darwin makefile, following
   on the Linux makefile.
 * Rewrite some of the implicit make rules to match one another more
   consistently.
 * Make corrections in the copyright years to match git log.

Makefile.am

@@ -1,6 +1,6 @@
 # Makefile.am, the source file for Makefile.in (and hence Makefile), is
 #
-# Copyright (c) 2018-2024 Cosmin Truta
+# Copyright (c) 2018-2025 Cosmin Truta
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
@@ -199,7 +199,7 @@ MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.guess config.h.in \
 config.sub configure depcomp install-sh ltmain.sh missing
 
 # PNG_COPTS give extra options for the C compiler to be used on all compilation
-# steps (unless targe_CFLAGS is specified; that will take precedence over
+# steps (unless target_CFLAGS is specified; that will take precedence over
 # AM_CFLAGS)
 PNG_COPTS = @PNG_COPTS@
 AM_CFLAGS = ${PNG_COPTS}

Makefile.in

@@ -16,7 +16,7 @@
 
 # Makefile.am, the source file for Makefile.in (and hence Makefile), is
 #
-# Copyright (c) 2018-2024 Cosmin Truta
+# Copyright (c) 2018-2025 Cosmin Truta
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
@@ -687,7 +687,7 @@ PNGLIB_RELEASE = @PNGLIB_RELEASE@
 PNGLIB_VERSION = @PNGLIB_VERSION@
 
 # PNG_COPTS give extra options for the C compiler to be used on all compilation
-# steps (unless targe_CFLAGS is specified; that will take precedence over
+# steps (unless target_CFLAGS is specified; that will take precedence over
 # AM_CFLAGS)
 PNG_COPTS = @PNG_COPTS@
 PNG_PREFIX = @PNG_PREFIX@

aclocal.m4

@@ -899,7 +899,7 @@ am_cv_filesystem_timestamp_resolution=2
 # Don't try 1 sec, because if 0.01 sec and 0.1 sec don't work,
 # - 1 sec is not much of a win compared to 2 sec, and
 # - it takes 2 seconds to perform the test whether 1 sec works.
-#
+# 
 # Instead, just use the default 2s on platforms that have 1s resolution,
 # accept the extra 1s delay when using $sleep in the Automake tests, in
 # exchange for not incurring the 2s delay for running the test for all
@@ -972,7 +972,7 @@ for am_try_res in $am_try_resolutions; do
       # everything else supports the subsecond mtimes, but make doesn't;
       # notably on macOS, which ships make 3.81 from 2006 (the last one
       # released under GPLv2). https://bugs.gnu.org/68808
-      #
+      # 
       # We test $MAKE if it is defined in the environment, else "make".
       # It might get overridden later, but our hope is that in practice
       # it does not matter: it is the system "make" which is (by far)

contrib/pngminus/.editorconfig

@@ -0,0 +1,29 @@
+# https://editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = unset
+indent_size = unset
+indent_style = space
+insert_final_newline = true
+max_doc_length = 79
+max_line_length = 79
+trim_trailing_whitespace = true
+
+[*.[ch]]
+indent_size = 2
+indent_style = space
+
+[CMakeLists.txt]
+indent_size = 4
+indent_style = space
+max_doc_length = 79
+max_line_length = 99
+
+[{Makefile,makevms.com}]
+indent_size = unset
+indent_style = unset
+max_doc_length = 79
+max_line_length = 99

contrib/pngminus/CHANGES.txt

@@ -11,3 +11,4 @@ version 1.0 - 1999.10.15 - First version.
         1.6 - 2018.08.05 - Improve portability and fix style (Cosmin Truta)
         1.7 - 2019.01.22 - Change license to MIT (Willem van Schaik)
         1.8 - 2024.01.09 - Fix, improve, modernize (Cosmin Truta)
+        1.9 - 2025.01.10 - Delete conditionally-compiled code (Cosmin Truta)

contrib/pngminus/CMakeLists.txt

@@ -1,9 +1,9 @@
-# Copyright (c) 2018-2024 Cosmin Truta
+# Copyright (c) 2018-2025 Cosmin Truta
 #
 # This software is released under the MIT license. For conditions of
 # distribution and use, see the LICENSE file part of this package.
 
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.14)
 
 project(PNGMINUS C)
 

contrib/pngminus/png2pnm.c

@@ -66,7 +66,7 @@ int main (int argc, char *argv[])
           if ((fp_al = fopen (argv[argi], "wb")) == NULL)
           {
             fname_al = argv[argi];
-            fprintf (stderr, "PNM2PNG\n");
+            fprintf (stderr, "PNG2PNM\n");
             fprintf (stderr, "Error:  cannot create alpha-channel file %s\n",
                      argv[argi]);
             exit (1);
@@ -235,22 +235,6 @@ BOOL do_png2pnm (png_struct *png_ptr, png_info *info_ptr,
   /* set up (if applicable) the expansion of grayscale images to bit-depth 8 */
   png_set_expand_gray_1_2_4_to_8 (png_ptr);
 
-#ifdef NJET
-  /* downgrade 16-bit images to 8-bit */
-  if (bit_depth == 16)
-    png_set_strip_16 (png_ptr);
-  /* transform grayscale images into full-color */
-  if (color_type == PNG_COLOR_TYPE_GRAY ||
-      color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-    png_set_gray_to_rgb (png_ptr);
-  /* if the PNG image has a gAMA chunk then gamma-correct the output image */
-  {
-    double file_gamma;
-    if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
-      png_set_gamma (png_ptr, (double) 2.2, file_gamma);
-  }
-#endif
-
   /* read the image file, with all of the above image transforms applied */
   png_read_png (png_ptr, info_ptr, 0, NULL);
 

png.c

@@ -1544,56 +1544,59 @@ png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy)
     *  Adobe Wide Gamut RGB
     *    0.258728243040113 0.724682314948566 0.016589442011321
     */
-   int error = 0;
+   {
+      int error = 0;
 
-   /* By the argument above overflow should be impossible here, however the
-    * code now simply returns a failure code.  The xy subtracts in the arguments
-    * to png_muldiv are *not* checked for overflow because the checks at the
-    * start guarantee they are in the range 0..110000 and png_fixed_point is a
-    * 32-bit signed number.
-    */
-   if (png_muldiv(&left, xy->greenx-xy->bluex, xy->redy - xy->bluey, 8) == 0)
-      return 1;
-   if (png_muldiv(&right, xy->greeny-xy->bluey, xy->redx - xy->bluex, 8) == 0)
-      return 1;
-   denominator = png_fp_sub(left, right, &error);
-   if (error) return 1;
+      /* By the argument above overflow should be impossible here, however the
+       * code now simply returns a failure code.  The xy subtracts in the
+       * arguments to png_muldiv are *not* checked for overflow because the
+       * checks at the start guarantee they are in the range 0..110000 and
+       * png_fixed_point is a 32-bit signed number.
+       */
+      if (png_muldiv(&left, xy->greenx-xy->bluex, xy->redy - xy->bluey, 8) == 0)
+         return 1;
+      if (png_muldiv(&right, xy->greeny-xy->bluey, xy->redx - xy->bluex, 8) ==
+            0)
+         return 1;
+      denominator = png_fp_sub(left, right, &error);
+      if (error) return 1;
 
-   /* Now find the red numerator. */
-   if (png_muldiv(&left, xy->greenx-xy->bluex, xy->whitey-xy->bluey, 8) == 0)
-      return 1;
-   if (png_muldiv(&right, xy->greeny-xy->bluey, xy->whitex-xy->bluex, 8) == 0)
-      return 1;
+      /* Now find the red numerator. */
+      if (png_muldiv(&left, xy->greenx-xy->bluex, xy->whitey-xy->bluey, 8) == 0)
+         return 1;
+      if (png_muldiv(&right, xy->greeny-xy->bluey, xy->whitex-xy->bluex, 8) ==
+            0)
+         return 1;
 
-   /* Overflow is possible here and it indicates an extreme set of PNG cHRM
-    * chunk values.  This calculation actually returns the reciprocal of the
-    * scale value because this allows us to delay the multiplication of white-y
-    * into the denominator, which tends to produce a small number.
-    */
-   if (png_muldiv(&red_inverse, xy->whitey, denominator,
-                  png_fp_sub(left, right, &error)) == 0 || error ||
-       red_inverse <= xy->whitey /* r+g+b scales = white scale */)
-      return 1;
+      /* Overflow is possible here and it indicates an extreme set of PNG cHRM
+       * chunk values.  This calculation actually returns the reciprocal of the
+       * scale value because this allows us to delay the multiplication of
+       * white-y into the denominator, which tends to produce a small number.
+       */
+      if (png_muldiv(&red_inverse, xy->whitey, denominator,
+                     png_fp_sub(left, right, &error)) == 0 || error ||
+          red_inverse <= xy->whitey /* r+g+b scales = white scale */)
+         return 1;
 
-   /* Similarly for green_inverse: */
-   if (png_muldiv(&left, xy->redy-xy->bluey, xy->whitex-xy->bluex, 8) == 0)
-      return 1;
-   if (png_muldiv(&right, xy->redx-xy->bluex, xy->whitey-xy->bluey, 8) == 0)
-      return 1;
-   if (png_muldiv(&green_inverse, xy->whitey, denominator,
-                  png_fp_sub(left, right, &error)) == 0 || error ||
-       green_inverse <= xy->whitey)
-      return 1;
-
-   /* And the blue scale, the checks above guarantee this can't overflow but it
-    * can still produce 0 for extreme cHRM values.
-    */
-   blue_scale = png_fp_sub(png_fp_sub(png_reciprocal(xy->whitey),
-                                      png_reciprocal(red_inverse), &error),
-                           png_reciprocal(green_inverse), &error);
-   if (error || blue_scale <= 0)
-      return 1;
+      /* Similarly for green_inverse: */
+      if (png_muldiv(&left, xy->redy-xy->bluey, xy->whitex-xy->bluex, 8) == 0)
+         return 1;
+      if (png_muldiv(&right, xy->redx-xy->bluex, xy->whitey-xy->bluey, 8) == 0)
+         return 1;
+      if (png_muldiv(&green_inverse, xy->whitey, denominator,
+                     png_fp_sub(left, right, &error)) == 0 || error ||
+          green_inverse <= xy->whitey)
+         return 1;
 
+      /* And the blue scale, the checks above guarantee this can't overflow but
+       * it can still produce 0 for extreme cHRM values.
+       */
+      blue_scale = png_fp_sub(png_fp_sub(png_reciprocal(xy->whitey),
+                                         png_reciprocal(red_inverse), &error),
+                              png_reciprocal(green_inverse), &error);
+      if (error || blue_scale <= 0)
+         return 1;
+   }
 
    /* And fill in the png_XYZ.  Again the subtracts are safe because of the
     * checks on the xy values at the start (the subtracts just calculate the

png.h

@@ -2005,27 +2005,27 @@ PNG_EXPORT(251, void, png_set_cICP, (png_const_structrp png_ptr,
 #ifdef PNG_cLLI_SUPPORTED
 PNG_FP_EXPORT(252, png_uint_32, png_get_cLLI, (png_const_structrp png_ptr,
          png_const_inforp info_ptr, double *maximum_content_light_level,
-         double *maximum_frame_average_light_level));
+         double *maximum_frame_average_light_level))
 PNG_FIXED_EXPORT(253, png_uint_32, png_get_cLLI_fixed,
     (png_const_structrp png_ptr, png_const_inforp info_ptr,
     /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
      * 100,000 as in the case of png_fixed_point.
      */
     png_uint_32p maximum_content_light_level_scaled_by_10000,
-    png_uint_32p maximum_frame_average_light_level_scaled_by_10000));
+    png_uint_32p maximum_frame_average_light_level_scaled_by_10000))
 #endif
 
 #ifdef PNG_cLLI_SUPPORTED
 PNG_FP_EXPORT(254, void, png_set_cLLI, (png_const_structrp png_ptr,
          png_inforp info_ptr, double maximum_content_light_level,
-         double maximum_frame_average_light_level));
+         double maximum_frame_average_light_level))
 PNG_FIXED_EXPORT(255, void, png_set_cLLI_fixed, (png_const_structrp png_ptr,
     png_inforp info_ptr,
     /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
      * 100,000 as in the case of png_fixed_point.
      */
     png_uint_32 maximum_content_light_level_scaled_by_10000,
-    png_uint_32 maximum_frame_average_light_level_scaled_by_10000));
+    png_uint_32 maximum_frame_average_light_level_scaled_by_10000))
 #endif
 
 #ifdef PNG_eXIf_SUPPORTED
@@ -2083,7 +2083,7 @@ PNG_FP_EXPORT(256, png_uint_32, png_get_mDCV, (png_const_structrp png_ptr,
     double *green_x, double *green_y, double *blue_x, double *blue_y,
     /* Mastering display luminance in cd/m2 (nits). */
     double *mastering_display_maximum_luminance,
-    double *mastering_display_minimum_luminance));
+    double *mastering_display_minimum_luminance))
 
 PNG_FIXED_EXPORT(257, png_uint_32, png_get_mDCV_fixed,
     (png_const_structrp png_ptr, png_const_inforp info_ptr,
@@ -2095,7 +2095,7 @@ PNG_FIXED_EXPORT(257, png_uint_32, png_get_mDCV_fixed,
      * 10,000.
      */
     png_uint_32p mastering_display_maximum_luminance_scaled_by_10000,
-    png_uint_32p mastering_display_minimum_luminance_scaled_by_10000));
+    png_uint_32p mastering_display_minimum_luminance_scaled_by_10000))
 #endif
 
 #ifdef PNG_mDCV_SUPPORTED
@@ -2108,7 +2108,7 @@ PNG_FP_EXPORT(258, void, png_set_mDCV, (png_const_structrp png_ptr,
     double green_y, double blue_x, double blue_y,
     /* Mastering display luminance in cd/m2 (nits). */
     double mastering_display_maximum_luminance,
-    double mastering_display_minimum_luminance));
+    double mastering_display_minimum_luminance))
 
 PNG_FIXED_EXPORT(259, void, png_set_mDCV_fixed, (png_const_structrp png_ptr,
     png_inforp info_ptr,
@@ -2123,7 +2123,7 @@ PNG_FIXED_EXPORT(259, void, png_set_mDCV_fixed, (png_const_structrp png_ptr,
      * must be zero.
      */
     png_uint_32 mastering_display_maximum_luminance_scaled_by_10000,
-    png_uint_32 mastering_display_minimum_luminance_scaled_by_10000));
+    png_uint_32 mastering_display_minimum_luminance_scaled_by_10000))
 #endif
 
 #ifdef PNG_oFFs_SUPPORTED

scripts/makefile.32sunu

@@ -1,6 +1,6 @@
 # makefile for libpng on Solaris 2.x with cc
 # Contributed by William L. Sebok, based on makefile.linux
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2002, 2006, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1998 Greg Roelofs
 # Copyright (C) 1996, 1997 Andreas Dilger
@@ -36,13 +36,10 @@ SUN_LD_FLAGS=-fast -xtarget=ultra
 ZLIBLIB=/usr/lib
 ZLIBINC=/usr/include
 
-WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-	-Wmissing-declarations -Wtraditional -Wcast-align \
-	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
 CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
-CFLAGS=$(SUN_CC_FLAGS) # $(WARNMORE) -g
+CFLAGS=$(SUN_CC_FLAGS) # -g
 ARFLAGS=rc
-LDFLAGS=$(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB) libpng.a -lz -lm
+LDFLAGS=$(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB) libpng.a -lz -lm # -g
 
 OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
        pngread.o pngrio.o pngrtran.o pngrutil.o pngset.o \
@@ -53,7 +50,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:      .c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 .c.pic.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -KPIC -o $@ $*.c

scripts/makefile.64sunu

@@ -1,6 +1,6 @@
 # makefile for libpng on Solaris 2.x with cc
 # Contributed by William L. Sebok, based on makefile.linux
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2002, 2006, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1998 Greg Roelofs
 # Copyright (C) 1996, 1997 Andreas Dilger
@@ -36,13 +36,10 @@ SUN_LD_FLAGS=-fast -xtarget=ultra -xarch=v9
 ZLIBLIB=/usr/lib
 ZLIBINC=/usr/include
 
-WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-	-Wmissing-declarations -Wtraditional -Wcast-align \
-	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
 CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
-CFLAGS=$(SUN_CC_FLAGS) # $(WARNMORE) -g
+CFLAGS=$(SUN_CC_FLAGS) # -g
 ARFLAGS=rc
-LDFLAGS=-L. -R. $(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng16 -lz -lm
+LDFLAGS=-L. -R. $(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng16 -lz -lm # -g
 
 OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
        pngread.o pngrio.o pngrtran.o pngrutil.o pngset.o \
@@ -53,7 +50,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:      .c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 .c.pic.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -KPIC -o $@ $*.c

scripts/makefile.aix

@@ -1,5 +1,5 @@
 # makefile for libpng using gcc (generic, static library)
-# Copyright (C) 2000, 2020-2024 Cosmin Truta
+# Copyright (C) 2000, 2020-2025 Cosmin Truta
 # Copyright (C) 2002, 2006-2009, 2014 Glenn Randers-Pehrson
 # Copyright (C) 2000 Marc O. Gloor (AIX support added, from makefile.gcc)
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
@@ -22,9 +22,8 @@ RM_F = rm -f
 LIBNAME = libpng16
 PNGMAJ = 16
 
-WARNMORE =
 CPPFLAGS = -I$(ZLIBINC) # -DPNG_DEBUG=5
-CFLAGS = -O2 -Wall -Wextra -Wundef # $(WARNMORE) -g
+CFLAGS = -O2 # -g
 ARFLAGS = rc
 LDFLAGS = -L. -L$(ZLIBLIB) -lpng16 -lz -lm # -g
 
@@ -35,7 +34,7 @@ OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
 
 # Targets
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 all: $(LIBNAME).a pngtest
 

scripts/makefile.atari

@@ -1,5 +1,5 @@
 # makefile for libpng
-# Copyright (C) 2022 Cosmin Truta
+# Copyright (C) 2022-2025 Cosmin Truta
 # Copyright (C) 2002, 2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -28,7 +28,7 @@ OBJS = $(LBR)(png.o) $(LBR)(pngerror.o) $(LBR)(pngget.o) $(LBR)(pngmem.o) \
 all: $(LBR) pngtest.ttp
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $*.c
 
 $(LBR): $(OBJS)
 

scripts/makefile.beos

@@ -1,6 +1,6 @@
 # makefile for libpng on BeOS x86 ELF with gcc
 # modified from makefile.linux by Sander Stoks
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2020-2025 Cosmin Truta
 # Copyright (C) 2002, 2006, 2008, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1999 Greg Roelofs
 # Copyright (C) 1996, 1997 Andreas Dilger
@@ -33,14 +33,10 @@ ALIGN=
 # For i386:
 # ALIGN=-malign-loops=2 -malign-functions=2
 
-WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-	-Wmissing-declarations -Wtraditional -Wcast-align \
-	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
-
 # On BeOS, -O1 is actually better than -O3.  This is a known bug but it's
 # still here in R4.5
 CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
-CFLAGS=-O1 -funroll-loops $(ALIGN) -Wall -Wextra -Wundef # $(WARNMORE) -g
+CFLAGS=-O1 -funroll-loops $(ALIGN) # -g
 ARFLAGS=rc
 # LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng -lz
 LDFLAGS=-L. -Wl,-soname=$(LIBSOMAJ) -L$(ZLIBLIB) -lz # -g
@@ -58,7 +54,7 @@ OBJSDLL = $(OBJS)
 .SUFFIXES:      .c .o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 all: libpng.a $(LIBSO) pngtest
 

scripts/makefile.c89

@@ -0,0 +1,97 @@
+# makefile for libpng using an ANSI C89 compiler
+# Copyright (C) 2000, 2014, 2019-2025 Cosmin Truta
+# Copyright (C) 2008, 2014 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Location of the zlib library and include files
+ZLIBINC = ../zlib
+ZLIBLIB = ../zlib
+
+# Compiler, linker, lib and other tools
+#CC = c89
+CC = cc
+LD = $(CC)
+AR = ar
+RANLIB = ranlib
+CP = cp
+RM_F = rm -f
+
+# Compiler and linker flags
+NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
+          -DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
+STDC = -pedantic-errors -std=c89
+WARN = -Wall -Wextra -Wundef
+WARNMORE = -Wcast-align -Wconversion -Wshadow -Wpointer-arith -Wwrite-strings \
+           -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes
+LOCAL_CPPFLAGS = $(NOHWOPT)
+CPPFLAGS = -I$(ZLIBINC) # -DPNG_DEBUG=5
+ALL_CPPFLAGS = $(LOCAL_CPPFLAGS) $(CPPFLAGS)
+LOCAL_CFLAGS = $(STDC) $(WARN) # $(WARNMORE)
+CFLAGS = -O2 # -g
+ALL_CFLAGS = $(LOCAL_CFLAGS) $(CFLAGS)
+ARFLAGS = rc
+LDFLAGS = -L$(ZLIBLIB) # -g
+LIBS = -lz -lm
+
+# File extensions
+EXEEXT =
+
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
+# File lists
+OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
+       pngread.o pngrio.o pngrtran.o pngrutil.o pngset.o \
+       pngtrans.o pngwio.o pngwrite.o pngwtran.o pngwutil.o
+
+# Targets
+all: static
+
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $(PNGLIBCONF_H_PREBUILT) $@
+
+.c.o:
+	$(CC) -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -o $@ $*.c
+
+static: libpng.a pngtest$(EXEEXT)
+
+shared:
+	@echo This is a generic makefile that cannot create shared libraries.
+	@echo Please use a configuration that is specific to your platform.
+	@false
+
+libpng.a: $(OBJS)
+	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(RANLIB) $@
+
+test: pngtest$(EXEEXT)
+	./pngtest$(EXEEXT)
+
+pngtest$(EXEEXT): pngtest.o libpng.a
+	$(LD) $(LDFLAGS) -o $@ pngtest.o libpng.a $(LIBS)
+
+clean:
+	$(RM_F) *.o libpng.a pngtest$(EXEEXT) pngout.png pnglibconf.h
+
+png.o:      png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o:  png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+
+pngtest.o:  png.h pngconf.h pnglibconf.h

scripts/makefile.clang

@@ -1,5 +1,5 @@
 # makefile for libpng using clang (generic, static library)
-# Copyright (C) 2000, 2014, 2019-2024 Cosmin Truta
+# Copyright (C) 2000, 2014, 2019-2025 Cosmin Truta
 # Copyright (C) 2008, 2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -21,13 +21,17 @@ RM_F = rm -f
 
 # Compiler and linker flags
 NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
-	-DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
-WARNMORE = -Wwrite-strings -Wpointer-arith -Wshadow \
-	-Wmissing-declarations -Wtraditional -Wcast-align \
-	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
-DEFS = $(NOHWOPT)
-CPPFLAGS = -I$(ZLIBINC) $(DEFS) # -DPNG_DEBUG=5
-CFLAGS = -O2 -Wall -Wextra -Wundef # $(WARNMORE) -g
+          -DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
+STDC = -pedantic-errors # -std=c99
+WARN = -Wall -Wextra -Wundef
+WARNMORE = -Wcast-align -Wconversion -Wshadow -Wpointer-arith -Wwrite-strings \
+           -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes
+LOCAL_CPPFLAGS = $(NOHWOPT)
+CPPFLAGS = -I$(ZLIBINC) # -DPNG_DEBUG=5
+ALL_CPPFLAGS = $(LOCAL_CPPFLAGS) $(CPPFLAGS)
+LOCAL_CFLAGS = $(STDC) $(WARN) # $(WARNMORE)
+CFLAGS = -O2 # -g
+ALL_CFLAGS = $(LOCAL_CFLAGS) $(CFLAGS)
 ARFLAGS = rc
 LDFLAGS = -L$(ZLIBLIB) # -g
 LIBS = -lz -lm
@@ -51,7 +55,7 @@ pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
 	$(CP) $(PNGLIBCONF_H_PREBUILT) $@
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -o $@ $*.c
 
 static: libpng.a pngtest$(EXEEXT)
 

scripts/makefile.darwin

@@ -1,5 +1,5 @@
 # makefile for libpng on Darwin / macOS
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2014, 2018-2025 Cosmin Truta
 # Copyright (C) 2002, 2004, 2006, 2008, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 2001 Christoph Pfisterer
 # derived from makefile.linux:
@@ -10,10 +10,6 @@
 # For conditions of distribution and use, see the disclaimer
 # and license in png.h
 
-# Where the zlib library and include files are located
-ZLIBLIB=/usr/lib
-ZLIBINC=/usr/include
-
 # Library name:
 LIBNAME=libpng16
 PNGMAJ=16
@@ -30,13 +26,22 @@ LN_SF=ln -sf
 CP=cp
 RM_F=rm -f
 
-NOHWOPT=-DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
-        -DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
-DEFS=$(NOHWOPT)
-CPPFLAGS=-I$(ZLIBINC) $(DEFS)
-CFLAGS=-O3 -funroll-loops -Wall -Wextra -Wundef
-ARFLAGS=rc
-LDFLAGS=-L. -L$(ZLIBLIB) -lpng16 -lz
+# Compiler and linker flags
+NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
+          -DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
+STDC = -pedantic-errors
+WARN = -Wall -Wextra -Wundef
+WARNMORE = -Wcast-align -Wconversion -Wshadow -Wpointer-arith -Wwrite-strings \
+           -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes
+LOCAL_CPPFLAGS = $(NOHWOPT)
+CPPFLAGS = # -DPNG_DEBUG=5
+ALL_CPPFLAGS = $(LOCAL_CPPFLAGS) $(CPPFLAGS)
+LOCAL_CFLAGS = $(STDC) $(WARN) # $(WARNMORE)
+CFLAGS = -O3 -funroll-loops # -g
+ALL_CFLAGS = $(LOCAL_CFLAGS) $(CFLAGS)
+ARFLAGS = rc
+LDFLAGS = -L. -lpng16 -lz # -g
+LDFLAGS_A = libpng.a -lz -lm # -g
 
 # Pre-built configuration
 # See scripts/pnglibconf.mak for more options
@@ -52,12 +57,12 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:      .c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -o $@ $*.c
 
 .c.pic.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -fno-common -o $@ $*.c
+	$(CC) -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -fno-common -o $@ $*.c
 
-all: libpng.a $(LIBSO) pngtest
+all: libpng.a $(LIBSO) pngtest pngtest-static
 
 pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
 	$(CP) $(PNGLIBCONF_H_PREBUILT) $@
@@ -71,15 +76,25 @@ $(LIBSO): $(LIBSOMAJ)
 
 $(LIBSOMAJ): $(OBJSDLL)
 	$(CC) -dynamiclib \
-	 -current_version 16 -compatibility_version 16 \
-	 -o $(LIBSOMAJ) \
-	 $(OBJSDLL) -L$(ZLIBLIB) -lz
+	      -current_version 16 -compatibility_version 16 \
+	      -o $(LIBSOMAJ) \
+	      $(OBJSDLL) -lz
 
 pngtest: pngtest.o $(LIBSO)
 	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
 
-test: pngtest
+pngtest-static: pngtest.o libpng.a
+	$(CC) -o pngtest-static $(CFLAGS) pngtest.o $(LDFLAGS_A)
+
+test: pngtest pngtest-static
+	@echo ""
+	@echo "   Running pngtest dynamically linked with $(LIBSO):"
+	@echo ""
 	./pngtest
+	@echo ""
+	@echo "   Running pngtest statically linked with libpng.a:"
+	@echo ""
+	./pngtest-static
 
 install:
 	@echo "The $@ target is no longer supported by this makefile."
@@ -94,8 +109,9 @@ install-shared:
 	@false
 
 clean:
-	$(RM_F) *.o libpng.a pngtest pngout.png
+	$(RM_F) $(OBJS) $(OBJSDLL) libpng.a
 	$(RM_F) $(LIBNAME).*dylib pnglibconf.h
+	$(RM_F) pngtest*.o pngtest pngtest-static pngout.png
 
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 

scripts/makefile.dec

@@ -1,5 +1,5 @@
 # makefile for libpng on DEC Alpha Unix
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2020-2025 Cosmin Truta
 # Copyright (C) 2000-2002, 2006, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -30,7 +30,7 @@ ZLIBLIB=../zlib
 ZLIBINC=../zlib
 
 CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
-CFLAGS=-std -w1 -O # -g
+CFLAGS=-std -w1 -O
 ARFLAGS=rc
 LDFLAGS=-L$(ZLIBLIB) -rpath $(ZLIBLIB) libpng.a -lz -lm
 
@@ -43,7 +43,7 @@ OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
        pngtrans.o pngwio.o pngwrite.o pngwtran.o pngwutil.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 all: $(LIBSO) libpng.a pngtest
 

scripts/makefile.dj2

@@ -1,5 +1,5 @@
 # DJGPP (DOS gcc) makefile for libpng
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2020-2025 Cosmin Truta
 # Copyright (C) 2002, 2006, 2009-2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -11,7 +11,7 @@ CC=gcc
 AR=ar
 RANLIB=ranlib
 CPPFLAGS=-I../zlib -DPNG_NO_SNPRINTF
-CFLAGS=-O
+CFLAGS=-O2 -Wall -Wextra -Wundef
 ARFLAGS=rc
 LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
 
@@ -27,7 +27,7 @@ OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
        pngtrans.o pngwio.o pngwrite.o pngwtran.o pngwutil.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 all: libpng.a pngtest
 

scripts/makefile.emcc

@@ -1,5 +1,5 @@
 # makefile for libpng using emscripten
-# Copyright (C) 2000, 2014, 2019-2024 Cosmin Truta
+# Copyright (C) 2000, 2014, 2019-2025 Cosmin Truta
 # Copyright (C) 2021 Kirk Roerig
 # Copyright (C) 2008, 2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
@@ -20,8 +20,16 @@ RANLIB = emranlib
 CP = cp
 RM_F = rm -f
 
+STDC = -pedantic-errors # -std=c99
+WARN = -Wall -Wextra -Wundef
+WARNMORE = -Wcast-align -Wconversion -Wshadow -Wpointer-arith -Wwrite-strings \
+           -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes
+LOCAL_CPPFLAGS =
 CPPFLAGS = -I$(ZLIBINC) # -DPNG_DEBUG=5
-CFLAGS = -O2 -Wall -Wextra -Wundef
+ALL_CPPFLAGS = $(LOCAL_CPPFLAGS) $(CPPFLAGS)
+LOCAL_CFLAGS = $(STDC) $(WARN) # $(WARNMORE)
+CFLAGS = -O2
+ALL_CFLAGS = $(LOCAL_CFLAGS) $(CFLAGS)
 ARFLAGS = rc
 LDFLAGS = -L$(ZLIBLIB)
 PNGTEST_LDFLAGS = --preload-file=pngtest.png
@@ -43,7 +51,7 @@ pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
 	$(CP) $(PNGLIBCONF_H_PREBUILT) $@
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -o $@ $*.c
 
 static: libpng.a pngtest
 

scripts/makefile.freebsd

@@ -1,5 +1,5 @@
 # makefile for libpng under FreeBSD
-# Copyright (C) 2020-2022 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2014 Glenn Randers-Pehrson and Andrey A. Chernov
 # Copyright (C) 2002, 2007, 2009 Glenn Randers-Pehrson and Andrey A. Chernov
 #
@@ -35,7 +35,7 @@ SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \
 	pngtrans.c pngwio.c pngwrite.c pngwtran.c pngwutil.c
 
 .c.o:
-	${CC} -c ${CPPFLAGS} ${CFLAGS} -o $@ $<
+	${CC} -c ${CPPFLAGS} ${CFLAGS} -o $@ $*.c
 
 pnglibconf.h:	${PNGLIBCONF_H_PREBUILT}
 	cp ${PNGLIBCONF_H_PREBUILT} $@

scripts/makefile.gcc

@@ -1,5 +1,5 @@
 # makefile for libpng using gcc (generic, static library)
-# Copyright (C) 2000, 2014, 2019-2024 Cosmin Truta
+# Copyright (C) 2000, 2014, 2019-2025 Cosmin Truta
 # Copyright (C) 2008, 2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -21,13 +21,17 @@ RM_F = rm -f
 
 # Compiler and linker flags
 NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
-	-DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
-WARNMORE = -Wwrite-strings -Wpointer-arith -Wshadow \
-	-Wmissing-declarations -Wtraditional -Wcast-align \
-	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
-DEFS = $(NOHWOPT)
-CPPFLAGS = -I$(ZLIBINC) $(DEFS) # -DPNG_DEBUG=5
-CFLAGS = -O2 -Wall -Wextra -Wundef # $(WARNMORE) -g
+          -DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
+STDC = -pedantic-errors # -std=c99
+WARN = -Wall -Wextra -Wundef
+WARNMORE = -Wcast-align -Wconversion -Wshadow -Wpointer-arith -Wwrite-strings \
+           -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes
+LOCAL_CPPFLAGS = $(NOHWOPT)
+CPPFLAGS = -I$(ZLIBINC) # -DPNG_DEBUG=5
+ALL_CPPFLAGS = $(LOCAL_CPPFLAGS) $(CPPFLAGS)
+LOCAL_CFLAGS = $(STDC) $(WARN) # $(WARNMORE)
+CFLAGS = -O2 # -g
+ALL_CFLAGS = $(LOCAL_CFLAGS) $(CFLAGS)
 ARFLAGS = rc
 LDFLAGS = -L$(ZLIBLIB) # -g
 LIBS = -lz -lm
@@ -51,7 +55,7 @@ pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
 	$(CP) $(PNGLIBCONF_H_PREBUILT) $@
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -o $@ $*.c
 
 static: libpng.a pngtest$(EXEEXT)
 

scripts/makefile.hp64

@@ -1,5 +1,5 @@
 # makefile for libpng, HPUX (10.20 and 11.00) using the ANSI/C product.
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 1999-2002, 2006, 2009, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42
 # Contributed by Jim Rice and updated by Chris Schleicher, Hewlett Packard
@@ -56,7 +56,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:	.c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 .c.pic.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) +z -o $@ $*.c

scripts/makefile.hpgcc

@@ -1,5 +1,5 @@
 # makefile for libpng on HP-UX using GCC with the HP ANSI/C linker.
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2002, 2006-2008, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 2001, Laurent faillie
 # Copyright (C) 1998, 1999 Greg Roelofs
@@ -37,12 +37,8 @@ ZLIBINC=/opt/zlib/include
 #   LDSHARED=ld -b
 #   SHAREDLIB=libz.sl
 
-WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-	-Wmissing-declarations -Wtraditional -Wcast-align \
-	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
-
 CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
-CFLAGS=-O3 -funroll-loops -Wall -Wextra -Wundef # $(WARNMORE) -g
+CFLAGS=-O3 -funroll-loops # -g
 ARFLAGS=rc
 #LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng16 -lz -lm # -g
 LDFLAGS=-L. -L$(ZLIBLIB) -lpng16 -lz -lm # -g
@@ -56,7 +52,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:      .c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 .c.pic.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -fPIC -o $@ $*.c

scripts/makefile.hpux

@@ -1,5 +1,5 @@
 # makefile for libpng, HPUX (10.20 and 11.00) using the ANSI/C product.
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 1999-2002, 2006, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42
 # Contributed by Jim Rice and updated by Chris Schleicher, Hewlett Packard
@@ -55,7 +55,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:	.c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 .c.pic.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) +z -o $@ $*.c

scripts/makefile.ibmc

@@ -1,7 +1,7 @@
 # Makefile for libpng (static)
 # IBM C version 3.x for Win32 and OS/2
 # Copyright (C) 2006, 2014 Glenn Randers-Pehrson
-# Copyright (C) 2000, 2020 Cosmin Truta
+# Copyright (C) 2000, 2020-2025 Cosmin Truta
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -46,7 +46,7 @@ LIBS = libpng$(A) $(ZLIBLIB)/zlib$(A)
 
 # Targets
 .c$(O):
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $*.c
 
 all: libpng$(A) pngtest$(E)
 

scripts/makefile.linux

@@ -1,5 +1,5 @@
 # makefile for libpng.a and libpng16.so on Linux ELF with gcc
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 1998, 1999, 2002, 2006, 2008, 2010-2014 Greg Roelofs and
 # Glenn Randers-Pehrson
 # Copyright (C) 1996, 1997 Andreas Dilger
@@ -24,24 +24,22 @@ LN_SF=ln -sf
 CP=cp
 RM_F=rm -f
 
-# Where the zlib library and include files are located.
-#ZLIBLIB=/usr/local/lib
-#ZLIBINC=/usr/local/include
-ZLIBLIB=../zlib
-ZLIBINC=../zlib
-
 # Compiler and linker flags
-NOHWOPT=-DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
-	-DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
-WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-	-Wmissing-declarations -Wtraditional -Wcast-align \
-	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
-DEFS=$(NOHWOPT)
-CPPFLAGS=-I$(ZLIBINC) $(DEFS) # -DPNG_DEBUG=5
-CFLAGS=-O3 -funroll-loops -Wall -Wextra -Wundef # $(WARNMORE) -g
-ARFLAGS=rc
-LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng16 -lz -lm # -g
-LDFLAGS_A=-L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) libpng.a -lz -lm # -g
+NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
+          -DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
+STDC = -pedantic-errors
+WARN = -Wall -Wextra -Wundef
+WARNMORE = -Wcast-align -Wconversion -Wshadow -Wpointer-arith -Wwrite-strings \
+           -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes
+LOCAL_CPPFLAGS = $(NOHWOPT)
+CPPFLAGS = # -DPNG_DEBUG=5
+ALL_CPPFLAGS = $(LOCAL_CPPFLAGS) $(CPPFLAGS)
+LOCAL_CFLAGS = $(STDC) $(WARN) # $(WARNMORE)
+CFLAGS = -O3 -funroll-loops # -g
+ALL_CFLAGS = $(LOCAL_CFLAGS) $(CFLAGS)
+ARFLAGS = rc
+LDFLAGS = -L. -Wl,-rpath,. -lpng16 -lz -lm # -g
+LDFLAGS_A = libpng.a -lz -lm # -g
 
 # Pre-built configuration
 # See scripts/pnglibconf.mak for more options
@@ -57,10 +55,10 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:      .c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -o $@ $*.c
 
 .c.pic.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -fPIC -o $@ $*.c
+	$(CC) -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -fPIC -o $@ $*.c
 
 all: libpng.a $(LIBSO) pngtest pngtest-static
 

scripts/makefile.mips

@@ -1,5 +1,5 @@
 # makefile for libpng
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 1998-2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -26,7 +26,7 @@ OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
        pngtrans.o pngwio.o pngwrite.o pngwtran.o pngwutil.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 all: libpng.a pngtest
 

scripts/makefile.msys

@@ -1,5 +1,5 @@
 # makefile for libpng using MSYS/gcc (shared, static library)
-# Copyright (C) 2000, 2019-2024 Cosmin Truta
+# Copyright (C) 2000, 2019-2025 Cosmin Truta
 # Copyright (C) 2012 Glenn Randers-Pehrson and Christopher M. Wheeler
 #
 # Portions taken from makefile.linux and makefile.gcc:
@@ -21,23 +21,28 @@ PNGMAJ=16
 LIBSO=$(LIBNAME).dll
 LIBSOMAJ=$(LIBNAME).dll.$(PNGMAJ)
 
-# Where the zlib library and include files are located.
-#ZLIBLIB=../zlib
-#ZLIBINC=../zlib
-ZLIBLIB=/usr/local/lib
-ZLIBINC=/usr/local/include
-
 # Compiler, linker, lib and other tools
 CC = gcc
 LD = $(CC)
 AR = ar
 RANLIB = ranlib
 CP = cp
-RM_F = rm -rf
+RM_F = rm -f
 LN_SF = ln -sf
 
+# Compiler and linker flags
+NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
+          -DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
+STDC = -pedantic-errors
+WARN = -Wall -Wextra -Wundef
+WARNMORE = -Wcast-align -Wconversion -Wshadow -Wpointer-arith -Wwrite-strings \
+           -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes
+LOCAL_CPPFLAGS = $(NOHWOPT)
 CPPFLAGS = # -DPNG_DEBUG=5
-CFLAGS = -O2 -Wall -Wextra -Wundef # -g
+ALL_CPPFLAGS = $(LOCAL_CPPFLAGS) $(CPPFLAGS)
+LOCAL_CFLAGS = $(STDC) $(WARN) # $(WARNMORE)
+CFLAGS = -O2 # -g
+ALL_CFLAGS = $(LOCAL_CFLAGS) $(CFLAGS)
 ARFLAGS = rc
 LDFLAGS = # -g
 LIBS = -lz -lm
@@ -61,7 +66,7 @@ pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
 	$(CP) $(PNGLIBCONF_H_PREBUILT) $@
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
+	$(CC) -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -o $@ $*.c
 
 static: libpng.a pngtest$(EXEEXT)
 

scripts/makefile.netbsd

@@ -1,5 +1,5 @@
 # makefile for libpng on NetBSD
-# Copyright (C) 2020-2022 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2007-2009, 2014 Glenn Randers-Pehrson
 # Copyright (C) 2002 Patrick R.L. Welche
 #
@@ -32,7 +32,7 @@ PNGLIBCONF_H_PREBUILT= scripts/pnglibconf.h.prebuilt
 # .endif
 
 .c.o:
-	${CC} -c ${CPPFLAGS} ${CFLAGS} -o $@ $<
+	${CC} -c ${CPPFLAGS} ${CFLAGS} -o $@ $*.c
 
 pnglibconf.h:	${PNGLIBCONF_H_PREBUILT}
 	cp ${PNGLIBCONF_H_PREBUILT} $@

scripts/makefile.openbsd

@@ -1,5 +1,5 @@
 # makefile for libpng
-# Copyright (C) 2020-2022 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2007-2009, 2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -26,7 +26,7 @@ CLEANFILES+=	pngtest.o pngtest pnglibconf.h
 PNGLIBCONF_H_PREBUILT= scripts/pnglibconf.h.prebuilt
 
 .c.o:
-	${CC} -c ${CPPFLAGS} ${CFLAGS} -o $@ $<
+	${CC} -c ${CPPFLAGS} ${CFLAGS} -o $@ $*.c
 
 pnglibconf.h:	${PNGLIBCONF_H_PREBUILT}
 	cp ${PNGLIBCONF_H_PREBUILT} $@

scripts/makefile.sco

@@ -1,7 +1,7 @@
 # makefile for SCO OSr5  ELF and Unixware 7 with Native cc
 # Contributed by Mike Hopkirk (hops at sco.com) modified from Makefile.lnx
 #   force ELF build dynamic linking, SONAME setting in lib and RPATH in app
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2002, 2006, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1998 Greg Roelofs
 # Copyright (C) 1996, 1997 Andreas Dilger
@@ -50,7 +50,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:      .c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 .c.pic.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -KPIC -o $@ $*.c

scripts/makefile.sggcc

@@ -1,5 +1,5 @@
 # makefile for libpng.a and libpng16.so, SGI IRIX with 'cc'
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2001-2002, 2006, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -35,9 +35,8 @@ ZLIBINC=../zlib
 # See "man abi".  zlib must be built with the same ABI.
 ABI=
 
-WARNMORE=
 CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
-CFLAGS=$(ABI) -O $(WARNMORE) -fPIC -mabi=n32 # -g
+CFLAGS=$(ABI) -O -fPIC -mabi=n32 # -g
 ARFLAGS=rc
 LDFLAGS=$(ABI) -L. -L$(ZLIBLIB) -lpng -lz -lm # -g
 LDSHARED=cc $(ABI) -shared -soname $(LIBSOMAJ) \
@@ -53,7 +52,7 @@ OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
        pngtrans.o pngwio.o pngwrite.o pngwtran.o pngwutil.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 all: libpng.a pngtest shared
 

scripts/makefile.sgi

@@ -1,5 +1,5 @@
 # makefile for libpng.a and libpng16.so, SGI IRIX with 'cc'
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2001-2002, 2006, 2007, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -35,11 +35,10 @@ ZLIBINC=../zlib
 # See "man abi".  zlib must be built with the same ABI.
 ABI=
 
-WARNMORE=-fullwarn
 # Note: -KPIC is the default anyhow
 CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
-#CFLAGS= $(ABI) -O $(WARNMORE) -KPIC # -g
-CFLAGS=$(ABI) -O $(WARNMORE) # -g
+#CFLAGS=$(ABI) -O -fullwarn -KPIC # -g
+CFLAGS=$(ABI) -O -fullwarn # -g
 ARFLAGS=rc
 LDFLAGS_A=$(ABI) -L. -L$(ZLIBLIB) -lpng16 -lz -lm # -g
 LDFLAGS=$(ABI) -L. -L$(ZLIBLIB) -lpng -lz -lm # -g
@@ -56,7 +55,7 @@ OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
        pngtrans.o pngwio.o pngwrite.o pngwtran.o pngwutil.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 all: libpng.a pngtest shared
 

scripts/makefile.so9

@@ -1,7 +1,7 @@
 # makefile for libpng on Solaris 9 (beta) with Forte cc
 # Updated by Chad Schrock for Solaris 9
 # Contributed by William L. Sebok, based on makefile.linux
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2002, 2006, 2008, 2010-2014 Glenn Randers-Pehrson
 # Copyright (C) 1998-2001 Greg Roelofs
 # Copyright (C) 1996-1997 Andreas Dilger
@@ -19,7 +19,6 @@ LIBSO=$(LIBNAME).so
 LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
 
 # Utilities:
-# gcc 2.95 doesn't work.
 CC=cc
 AR=ar
 RANLIB=echo
@@ -56,7 +55,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:      .c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 .c.pic.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -KPIC -o $@ $*.c

scripts/makefile.solaris

@@ -1,5 +1,5 @@
 # makefile for libpng on Solaris 2.x with gcc
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2004, 2006-2008, 2010-2014 Glenn Randers-Pehrson
 # Contributed by William L. Sebok, based on makefile.linux
 # Copyright (C) 1998 Greg Roelofs
@@ -34,11 +34,8 @@ RM_F=/bin/rm -f
 ZLIBLIB=/usr/local/lib
 ZLIBINC=/usr/local/include
 
-WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-	-Wmissing-declarations -Wtraditional -Wcast-align \
-	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
 CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
-CFLAGS=-O -Wall -Wextra -Wundef # $(WARNMORE) -g
+CFLAGS=-O # -g
 ARFLAGS=rc
 LDFLAGS=-L. -R. -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng16 -lz -lm # -g
 
@@ -55,7 +52,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 .SUFFIXES:      .c .o .pic.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 .c.pic.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -fPIC -o $@ $*.c

scripts/makefile.std

@@ -1,5 +1,5 @@
 # makefile for libpng
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2015, 2018-2025 Cosmin Truta
 # Copyright (C) 2002, 2006, 2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -23,7 +23,7 @@ RM_F = rm -f
 AWK = awk
 
 NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
-	-DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
+          -DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
 DFNFLAGS = # DFNFLAGS contains -D options to use in the libpng build
 DFA_EXTRA = # extra files that can be used to control configuration
 CPPFLAGS = -I$(ZLIBINC) $(NOHWOPT) # -DPNG_DEBUG=5
@@ -41,7 +41,7 @@ OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
        pngtrans.o pngwio.o pngwrite.o pngwtran.o pngwutil.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 all: libpng.a pngtest
 

scripts/makefile.sunos

@@ -1,5 +1,5 @@
 # makefile for libpng
-# Copyright (C) 2020-2024 Cosmin Truta
+# Copyright (C) 2018-2025 Cosmin Truta
 # Copyright (C) 2002, 2006, 2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -33,7 +33,7 @@ OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
        pngtrans.o pngwio.o pngwrite.o pngwtran.o pngwutil.o
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $*.c
 
 all: libpng.a pngtest