Mark some functions and variables as static (#2691)

These are only used in the same file, and not exported.

libvips/colour/LabQ2sRGB.c

@@ -75,7 +75,7 @@ G_DEFINE_TYPE( VipsLabQ2sRGB, vips_LabQ2sRGB, VIPS_TYPE_COLOUR_CODE );
  *
  * There's an extra element at the end to let us do a +1 for interpolation.
  */
-int vips_Y2v_8[256 + 1];
+static int vips_Y2v_8[256 + 1];
 
 /* 8-bit sRGB -> linear lut.
  */
@@ -85,7 +85,7 @@ float vips_v2Y_8[256];
  *
  * There's an extra element at the end to let us do a +1 for interpolation.
  */
-int vips_Y2v_16[65536 + 1];
+static int vips_Y2v_16[65536 + 1];
 
 /* 16-bit sRGB -> linear lut.
  */

libvips/colour/XYZ2Lab.c

@@ -69,7 +69,7 @@
  */
 #define QUANT_ELEMENTS (100000)
 
-float cbrt_table[QUANT_ELEMENTS];
+static float cbrt_table[QUANT_ELEMENTS];
 
 typedef struct _VipsXYZ2Lab {
 	VipsColourTransform parent_instance;

libvips/colour/dE00.c

@@ -206,7 +206,7 @@ vips_col_dE00( float L1, float a1, float b1,
 
 /* Find the difference between two buffers of LAB data.
  */
-void
+static void
 vips_dE00_line( VipsColour *colour, 
 	VipsPel *out, VipsPel **in, int width )
 {

libvips/colour/pcolour.h

@@ -208,9 +208,7 @@ void vips__pythagoras_line( VipsColour *colour,
 /* Colour tables for Y<->v conversion. Call vips_col_make_tables_RGB_8() and
  * vips_col_make_tables_RGB_16() before use to initialize.
  */
-extern int vips_Y2v_8[256 + 1];
 extern float vips_v2Y_8[256];
-extern int vips_Y2v_16[65536 + 1];
 extern float vips_v2Y_16[65536];
 
 void vips_col_make_tables_RGB_8( void );

libvips/foreign/dzsave.c

@@ -1177,7 +1177,7 @@ static char *scan_property_names[][2] = {
 /* Make the xml we write to scan-properties.xml in szi write.
  * Free with g_free().
  */
-char *
+static char *
 build_scan_properties( VipsImage *image )
 {
 	VipsDbuf dbuf;

libvips/foreign/heifsave.c

@@ -176,10 +176,14 @@ typedef struct heif_error (*libheif_metadata_fn)( struct heif_context *,
 	 const struct heif_image_handle *,
 	 const void *, int );
 
-struct _VipsForeignSaveHeifMetadata {
-	const char *name;
-	libheif_metadata_fn saver;
-} libheif_metadata[] = {
+/* String-based metadata fields we add.
+ */
+typedef struct _VipsForeignSaveHeifMetadata {
+	const char *name;		/* as understood by libvips */
+	libheif_metadata_fn saver;		/* as understood by libheif */
+} VipsForeignSaveHeifMetadata;
+
+static VipsForeignSaveHeifMetadata libheif_metadata[] = {
 	{ VIPS_META_EXIF_NAME, heif_context_add_exif_metadata },
 	{ VIPS_META_XMP_NAME, heif_context_add_XMP_metadata }
 };

libvips/iofuncs/image.c

@@ -1381,7 +1381,7 @@ vips_image_written( VipsImage *image )
 	return( result );
 }
 
-void
+static void
 vips_image_invalidate( VipsImage *image )
 {
 	VIPS_DEBUG_MSG( "vips_image_invalidate: %p\n", image );
@@ -1421,7 +1421,7 @@ vips_image_invalidate_all( VipsImage *image )
 		(VipsSListMap2Fn) vips_image_invalidate_all_cb, NULL, NULL );
 }
 
-void
+static void
 vips_image_minimise( VipsImage *image )
 {
 	VIPS_DEBUG_MSG( "vips_image_minimise: %p\n", image );
@@ -1681,7 +1681,7 @@ vips_image_set_kill( VipsImage *image, gboolean kill )
 /* Fills the given buffer with a temporary filename.
  * Assuming that "int" might be 64 Bit wide a buffer size of 26 suffices.
  */
-void
+static void
 vips_image_temp_name( char *name, int size )
 {
 	static int global_serial = 0;

libvips/iofuncs/type.c

@@ -179,7 +179,7 @@ vips_area_free_cb( void *mem, VipsArea *area )
 	return( 0 );
 }
 
-void
+static void
 vips_area_free( VipsArea *area )
 {
 	if( area->free_fn && 

libvips/iofuncs/vector.c

@@ -69,7 +69,7 @@
  */
 gboolean vips__vector_enabled = TRUE;
 
-void
+static void
 vips_vector_error( VipsVector *vector )
 {
 #ifdef HAVE_ORC

libvips/resample/interpolate.c

@@ -373,7 +373,7 @@ vips_interpolate_nearest_init( VipsInterpolateNearest *nearest )
 #endif /*DEBUG*/
 }
 
-VipsInterpolate *
+static VipsInterpolate *
 vips_interpolate_nearest_new( void )
 {
 	return( VIPS_INTERPOLATE( vips_object_new(