stty: code shrink

function                                             old     new   delta
set_mode                                             759     725     -34

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/coreutils/stty.c b/coreutils/stty.c
index 96754dd..c522968 100644 (file)
--- a/coreutils/stty.c
+++ b/coreutils/stty.c
@@ -246,10 +246,21 @@ enum speed_setting {
 
 /* Which member(s) of 'struct termios' a mode uses */
 enum {
-       /* Do NOT change the order or values, as mode_type_flag()
-        * depends on them */
        control, input, output, local, combination
 };
+static tcflag_t *get_ptr_to_tcflag(unsigned type, const struct termios *mode)
+{
+       static const uint8_t tcflag_offsets[] ALIGN1 = {
+               offsetof(struct termios, c_cflag), /* control */
+               offsetof(struct termios, c_iflag), /* input */
+               offsetof(struct termios, c_oflag), /* output */
+               offsetof(struct termios, c_lflag)  /* local */
+       };
+       if (type <= local) {
+               return (tcflag_t*) (((char*)mode) + tcflag_offsets[type]);
+       }
+       return NULL;
+}
 
 /* Flags for 'struct mode_info' */
 #define SANE_SET 1              /* Set in 'sane' mode                  */
@@ -800,21 +811,6 @@ static const char *visible(unsigned ch)
        return G.buf;
 }
 
-static tcflag_t *mode_type_flag(unsigned type, const struct termios *mode)
-{
-       static const uint8_t tcflag_offsets[] ALIGN1 = {
-               offsetof(struct termios, c_cflag), /* control */
-               offsetof(struct termios, c_iflag), /* input */
-               offsetof(struct termios, c_oflag), /* output */
-               offsetof(struct termios, c_lflag)  /* local */
-       };
-
-       if (type <= local) {
-               return (tcflag_t*) (((char*)mode) + tcflag_offsets[type]);
-       }
-       return NULL;
-}
-
 static void set_speed_or_die(enum speed_setting type, const char *arg,
                                        struct termios *mode)
 {
@@ -1072,7 +1068,7 @@ static void do_display(const struct termios *mode, int all)
                        prev_type = mode_info[i].type;
                }
 
-               bitsp = mode_type_flag(mode_info[i].type, mode);
+               bitsp = get_ptr_to_tcflag(mode_info[i].type, mode);
                mask = mode_info[i].mask ? mode_info[i].mask : mode_info[i].bits;
                if ((*bitsp & mask) == mode_info[i].bits) {
                        if (all || (mode_info[i].flags & SANE_UNSET))
@@ -1091,7 +1087,6 @@ static void do_display(const struct termios *mode, int all)
 static void sane_mode(struct termios *mode)
 {
        int i;
-       tcflag_t *bitsp;
 
        for (i = 0; i < NUM_control_info; ++i) {
 #if VMIN == VEOF
@@ -1102,14 +1097,17 @@ static void sane_mode(struct termios *mode)
        }
 
        for (i = 0; i < NUM_mode_info; ++i) {
+               tcflag_t val;
+               tcflag_t *bitsp = get_ptr_to_tcflag(mode_info[i].type, mode);
+
+               if (!bitsp)
+                       continue;
+               val = *bitsp & ~((unsigned long)mode_info[i].mask);
                if (mode_info[i].flags & SANE_SET) {
-                       bitsp = mode_type_flag(mode_info[i].type, mode);
-                       *bitsp = (*bitsp & ~((unsigned long)mode_info[i].mask))
-                               | mode_info[i].bits;
-               } else if (mode_info[i].flags & SANE_UNSET) {
-                       bitsp = mode_type_flag(mode_info[i].type, mode);
-                       *bitsp = *bitsp & ~((unsigned long)mode_info[i].mask)
-                               & ~mode_info[i].bits;
+                       *bitsp = val | mode_info[i].bits;
+               } else
+               if (mode_info[i].flags & SANE_UNSET) {
+                       *bitsp = val & ~mode_info[i].bits;
                }
        }
 }
@@ -1119,17 +1117,18 @@ static void set_mode(const struct mode_info *info, int reversed,
 {
        tcflag_t *bitsp;
 
-       bitsp = mode_type_flag(info->type, mode);
+       bitsp = get_ptr_to_tcflag(info->type, mode);
 
        if (bitsp) {
+               tcflag_t val = *bitsp & ~info->mask;
                if (reversed)
-                       *bitsp = *bitsp & ~info->mask & ~info->bits;
+                       *bitsp = val & ~info->bits;
                else
-                       *bitsp = (*bitsp & ~info->mask) | info->bits;
+                       *bitsp = val | info->bits;
                return;
        }
 
-       /* Combination mode */
+       /* !bitsp - it's a "combination" mode */
        if (info == &mode_info[IDX_evenp] || info == &mode_info[IDX_parity]) {
                if (reversed)
                        mode->c_cflag = (mode->c_cflag & ~PARENB & ~CSIZE) | CS8;