stty: code shrink

function                                             old     new   delta
set_mode                                             759     725     -34

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

1 files changed, 29 insertions, 30 deletions

diff --git a/coreutils/stty.c b/coreutils/stty.c
index 96754dd84..c52296871 100644
--- 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;