Reduce visibility wherever possible

When possible, declare functions/variables static and move struct
definitions out of headers.  In order to allow utf8decode to become
internal, use codepoint for DECSCUSR extension directly.

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

st.c

@@ -36,6 +36,7 @@
 
 /* Arbitrary sizes */
 #define UTF_INVALID   0xFFFD
+#define UTF_SIZ       4
 #define ESC_BUF_SIZ   (128*UTF_SIZ)
 #define ESC_ARG_SIZ   16
 #define STR_BUF_SIZ   ESC_BUF_SIZ
@@ -95,6 +96,31 @@ enum escape_state {
 	ESC_DCS        =128,
 };
 
+typedef struct {
+	Glyph attr; /* current char attributes */
+	int x;
+	int y;
+	char state;
+} TCursor;
+
+typedef struct {
+	int mode;
+	int type;
+	int snap;
+	/*
+	 * Selection variables:
+	 * nb – normalized coordinates of the beginning of the selection
+	 * ne – normalized coordinates of the end of the selection
+	 * ob – original coordinates of the beginning of the selection
+	 * oe – original coordinates of the end of the selection
+	 */
+	struct {
+		int x, y;
+	} nb, ne, ob, oe;
+
+	int alt;
+} Selection;
+
 /* Internal representation of the screen */
 typedef struct {
 	int row;      /* nb row */
@@ -187,15 +213,18 @@ static void tstrsequence(uchar);
 
 static void drawregion(int, int, int, int);
 
+static void selnormalize(void);
 static void selscroll(int, int);
 static void selsnap(int *, int *, int);
 
+static size_t utf8decode(const char *, Rune *, size_t);
 static Rune utf8decodebyte(char, size_t *);
 static char utf8encodebyte(Rune, size_t);
-static char *utf8strchr(char *s, Rune u);
+static char *utf8strchr(char *, Rune);
 static size_t utf8validate(Rune *, size_t);
 
 static char *base64dec(const char *);
+static char base64dec_getc(const char **);
 
 static ssize_t xwrite(int, const char *, size_t);
 

st.h

@@ -1,8 +1,5 @@
 /* See LICENSE for license details. */
 
-/* Arbitrary sizes */
-#define UTF_SIZ       4
-
 /* macros */
 #define MIN(a, b)		((a) < (b) ? (a) : (b))
 #define MAX(a, b)		((a) < (b) ? (b) : (a))
@@ -69,41 +66,6 @@ typedef struct {
 
 typedef Glyph *Line;
 
-typedef struct {
-	Glyph attr; /* current char attributes */
-	int x;
-	int y;
-	char state;
-} TCursor;
-
-/* Purely graphic info */
-typedef struct {
-	int tw, th; /* tty width and height */
-	int w, h; /* window width and height */
-	int ch; /* char height */
-	int cw; /* char width  */
-	int mode; /* window state/mode flags */
-	int cursor; /* cursor style */
-} TermWindow;
-
-typedef struct {
-	int mode;
-	int type;
-	int snap;
-	/*
-	 * Selection variables:
-	 * nb – normalized coordinates of the beginning of the selection
-	 * ne – normalized coordinates of the end of the selection
-	 * ob – original coordinates of the beginning of the selection
-	 * oe – original coordinates of the end of the selection
-	 */
-	struct {
-		int x, y;
-	} nb, ne, ob, oe;
-
-	int alt;
-} Selection;
-
 typedef union {
 	int i;
 	uint ui;
@@ -137,11 +99,9 @@ void selclear(void);
 void selinit(void);
 void selstart(int, int, int);
 void selextend(int, int, int, int);
-void selnormalize(void);
 int selected(int, int);
 char *getsel(void);
 
-size_t utf8decode(const char *, Rune *, size_t);
 size_t utf8encode(Rune, char *);
 
 void *xmalloc(size_t);

win.h

@@ -27,7 +27,6 @@ void xbell(void);
 void xclipcopy(void);
 void xdrawcursor(int, int, Glyph, int, int, Glyph);
 void xdrawline(Line, int, int, int);
-void xhints(void);
 void xfinishdraw(void);
 void xloadcols(void);
 int xsetcolorname(int, const char *);

x.c

@@ -75,6 +75,15 @@ typedef XftColor Color;
 typedef XftGlyphFontSpec GlyphFontSpec;
 
 /* Purely graphic info */
+typedef struct {
+	int tw, th; /* tty width and height */
+	int w, h; /* window width and height */
+	int ch; /* char height */
+	int cw; /* char width  */
+	int mode; /* window state/mode flags */
+	int cursor; /* cursor style */
+} TermWindow;
+
 typedef struct {
 	Display *dpy;
 	Colormap cmap;
@@ -133,6 +142,8 @@ static int xgeommasktogravity(int);
 static void xinit(int, int);
 static void cresize(int, int);
 static void xresize(int, int);
+static void xhints(void);
+static int xloadcolor(int, const char *, Color *);
 static int xloadfont(Font *, FcPattern *);
 static void xloadfonts(char *, double);
 static void xunloadfont(Font *);
@@ -1430,8 +1441,8 @@ xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
 	/* draw the new one */
 	if (IS_SET(MODE_FOCUSED)) {
 		switch (win.cursor) {
-		case 7: /* st extension: snowman */
+		case 7: /* st extension: snowman (U+2603) */
-			utf8decode("☃", &g.u, UTF_SIZ);
+			g.u = 0x2603;
 		case 0: /* Blinking Block */
 		case 1: /* Blinking Block (Default) */
 		case 2: /* Steady Block */