Add some initial wrapping for ports

* Imakefile (EXTRA_DEFINES, DEPEND_DEFINES, ANALYZE, OPTIMIZE):
Make port and compiler specific.
* compositor.h: Update compiler-specific defines.
* fns.c (PortPopcount): New function.
* seat.c (MaskPopCount): Use Popcount macro.

Imakefile

@@ -22,7 +22,13 @@ DependSubdirs($(SUBDIRS))
              OBJS = 12to11.o run.o alloc.o fns.o output.o compositor.o surface.o region.o shm.o atoms.o subcompositor.o positioner.o xdg_wm.o xdg_surface.o xdg_toplevel.o frame_clock.o xerror.o ewmh.o timer.o subsurface.o seat.o data_device.o xdg_popup.o dmabuf.o buffer.o select.o xdata.o xsettings.o dnd.o icon_surface.o primary_selection.o renderer.o picture_renderer.o explicit_synchronization.o transform.o wp_viewporter.o decoration.o text_input.o single_pixel_buffer.o drm_lease.o pointer_constraints.o time.o relative_pointer.o keyboard_shortcuts_inhibit.o idle_inhibit.o process.o fence_ring.o pointer_gestures.o test.o buffer_release.o
        GENHEADERS = transfer_atoms.h drm_modifiers.h
            HEADER = $(GENHEADERS) compositor.h
-   EXTRA_DEFINES := -D_GNU_SOURCE -U_BSD_SOURCE -U_SVID_SOURCE
+
+#if defined LinuxArchitecture || define GNUArchitecture
+   EXTRA_DEFINES := -DPortFile=\"port_gnu.h\" -D_GNU_SOURCE -U_BSD_SOURCE -U_SVID_SOURCE
+  DEPEND_DEFINES := -DPortFile=\"port_gnu.h\"
+#else
+# error "The protocol translator was not ported to your system"
+#endif
 
 #ifdef HaveEglSupport
 
@@ -46,8 +52,12 @@ cleandir::
 #endif
 
          OPTIMIZE = -O0
+#if GccMajorVersion >= 10
          ANALYZE  = -fanalyzer
+#endif
+#if GccMajorVersion >= 7
      CDEBUGFLAGS := -fno-common -Wall -Warith-conversion -Wdate-time -Wdisabled-optimization -Wdouble-promotion -Wduplicated-cond -Wextra -Wformat-signedness -Winit-self -Winvalid-pch -Wlogical-op -Wmissing-declarations -Wmissing-include-dirs -Wmissing-prototypes -Wnested-externs -Wnull-dereference -Wold-style-definition -Wopenmp-simd -Wpacked -Wpointer-arith -Wstrict-prototypes -Wsuggest-attribute=format -Wsuggest-attribute=noreturn -Wsuggest-final-methods -Wsuggest-final-types -Wuninitialized -Wunknown-pragmas -Wunused-macros -Wvariadic-macros -Wvector-operation-performance -Wwrite-strings -Warray-bounds=2 -Wattribute-alias=2 -Wformat=2 -Wformat-truncation=2 -Wimplicit-fallthrough=5 -Wshift-overflow=2 -Wuse-after-free=3 -Wvla-larger-than=4031 -Wredundant-decls -Wno-missing-field-initializers -Wno-override-init -Wno-sign-compare -Wno-type-limits -Wno-unused-parameter -Wno-format-nonliteral -g3 $(OPTIMIZE) $(ANALYZE)
+#endif
 
 short_types.txt: media_types.txt
 XCOMM	Remove all data types starting with application/vnd.

compositor.h

@@ -1853,10 +1853,16 @@ extern void ReleaseBufferWithHelper (BufferReleaseHelper *, ExtBuffer *,
         ? (t) -1						\
         : ((((t) 1 << (TypeWidth (t) - 2)) - 1) * 2 + 1)))
 
+#if __GNUC__ >= 7
+
 #define IntAddWrapv(a, b, r) 		__builtin_add_overflow (a, b, r)
 #define IntSubtractWrapv(a, b, r)	__builtin_sub_overflow (a, b, r)
 #define IntMultiplyWrapv(a, b, r)	__builtin_mul_overflow (a, b, r)
 
+#define Popcount(number)		__builtin_popcount (number)
+
+#endif
+
 /* This is a macro in order to be more static analyzer friendly.  */
 #define XLAssert(cond) (!(cond) ? abort () : ((void) 0))
 
@@ -1872,3 +1878,9 @@ struct _Rectangle
   /* The width and height.  */
   int width, height;
 };
+
+/* port.h may override ports here.  */
+
+#ifdef PortFile
+#include PortFile
+#endif

fns.c

@@ -891,3 +891,27 @@ XLAddFdFlag (int fd, int flag, Bool abort_on_error)
 
   return True;
 }
+
+/* Functions for ports.  */
+
+#ifdef NeedPortPopcount
+
+int
+PortPopcount (unsigned long long int big)
+{
+  int num_bits;
+
+  num_bits = 0;
+
+  while (big)
+    {
+      if (big & 1)
+	++num_bits;
+
+      big >>= 1;
+    }
+
+  return num_bits;
+}
+
+#endif /* NeedPortPopcount.  */

seat.c

@@ -3063,7 +3063,7 @@ MaskPopCount (XIButtonState *mask)
   population = 0;
 
   for (i = 0; i < mask->mask_len; ++i)
-    population += __builtin_popcount (mask->mask[i]);
+    population += Popcount (mask->mask[i]);
 
   return population;
 }