speeds & termios values are not constants for the Cosmopolitan libc

dinosaure · dinosaure · commit 3261327d59de · 2022-05-23T17:01:26.000+02:00
This patch create 2 C functions to initialize an array with speed values
or termios values. If we pass NULL to these functions, they returns the
length of the array. By this way, we initiate required arrays which
contains speeds &amp; termios value at the runtime - instead of the compile
time.

This patch is needed because these values are not constants for the
Cosmopolitan libc and we must set/initialize arrays at runtime.
diff --git a/src/unix/unix_c/unix_termios_conversion.c b/src/unix/unix_c/unix_termios_conversion.c
@@ -20,141 +20,161 @@ enum { Iflags, Oflags, Cflags, Lflags };
 
 /* Structure of the terminal_io record. Cf. unix.mli */
 
-static long terminal_io_descr[] = {
-    /* Input modes */
-    Bool, Iflags, IGNBRK, Bool, Iflags, BRKINT, Bool, Iflags, IGNPAR, Bool,
-    Iflags, PARMRK, Bool, Iflags, INPCK, Bool, Iflags, ISTRIP, Bool, Iflags,
-    INLCR, Bool, Iflags, IGNCR, Bool, Iflags, ICRNL, Bool, Iflags, IXON, Bool,
-    Iflags, IXOFF,
-    /* Output modes */
-    Bool, Oflags, OPOST,
-    /* Control modes */
-    Speed, Output, Speed, Input, Enum, Cflags, 5, 4, CSIZE, CS5, CS6, CS7, CS8,
-    Enum, Cflags, 1, 2, CSTOPB, 0, CSTOPB, Bool, Cflags, CREAD, Bool, Cflags,
-    PARENB, Bool, Cflags, PARODD, Bool, Cflags, HUPCL, Bool, Cflags, CLOCAL,
-    /* Local modes */
-    Bool, Lflags, ISIG, Bool, Lflags, ICANON, Bool, Lflags, NOFLSH, Bool,
-    Lflags, ECHO, Bool, Lflags, ECHOE, Bool, Lflags, ECHOK, Bool, Lflags,
-    ECHONL,
-    /* Control characters */
-    Char, VINTR, Char, VQUIT, Char, VERASE, Char, VKILL, Char, VEOF, Char, VEOL,
-    Char, VMIN, Char, VTIME, Char, VSTART, Char, VSTOP, End};
+static tcflag_t *choose_field(struct termios *terminal_status, long field)
+{
+    switch (field) {
+        case Iflags:
+            return &terminal_status->c_iflag;
+        case Oflags:
+            return &terminal_status->c_oflag;
+        case Cflags:
+            return &terminal_status->c_cflag;
+        case Lflags:
+            return &terminal_status->c_lflag;
+        default:
+            return 0;
+    }
+}
 
-static struct {
+struct speed_t {
     speed_t speed;
     int baud;
-} speedtable[] = {{B50, 50},
-                  {B75, 75},
-                  {B110, 110},
-                  {B134, 134},
-                  {B150, 150},
+};
+
+long _speedtable(struct speed_t dst[]) {
+  struct speed_t speedtable[] = {
+	  {B50, 50},
+          {B75, 75},
+          {B110, 110},
+          {B134, 134},
+          {B150, 150},
 #ifdef B200
-                  {B200, 200},
+          {B200, 200},
 #endif
-                  {B300, 300},
-                  {B600, 600},
-                  {B1200, 1200},
-                  {B1800, 1800},
-                  {B2400, 2400},
-                  {B4800, 4800},
-                  {B9600, 9600},
-                  {B19200, 19200},
-                  {B38400, 38400},
+          {B300, 300},
+          {B600, 600},
+          {B1200, 1200},
+          {B1800, 1800},
+          {B2400, 2400},
+          {B4800, 4800},
+          {B9600, 9600},
+          {B19200, 19200},
+          {B38400, 38400},
 #ifdef B57600
-                  {B57600, 57600},
+          {B57600, 57600},
 #endif
 #ifdef B115200
-                  {B115200, 115200},
+          {B115200, 115200},
 #endif
 #ifdef B230400
-                  {B230400, 230400},
+          {B230400, 230400},
 #endif
-                  {B0, 0},
+          {B0, 0},
 
                   /* Linux extensions */
 #ifdef B460800
-                  {B460800, 460800},
+          {B460800, 460800},
 #endif
 #ifdef B500000
-                  {B500000, 500000},
+          {B500000, 500000},
 #endif
 #ifdef B576000
-                  {B576000, 576000},
+          {B576000, 576000},
 #endif
 #ifdef B921600
-                  {B921600, 921600},
+          {B921600, 921600},
 #endif
 #ifdef B1000000
-                  {B1000000, 1000000},
+          {B1000000, 1000000},
 #endif
 #ifdef B1152000
-                  {B1152000, 1152000},
+          {B1152000, 1152000},
 #endif
 #ifdef B1500000
-                  {B1500000, 1500000},
+          {B1500000, 1500000},
 #endif
 #ifdef B2000000
-                  {B2000000, 2000000},
+          {B2000000, 2000000},
 #endif
 #ifdef B2500000
-                  {B2500000, 2500000},
+          {B2500000, 2500000},
 #endif
 #ifdef B3000000
-                  {B3000000, 3000000},
+          {B3000000, 3000000},
 #endif
 #ifdef B3500000
-                  {B3500000, 3500000},
+          {B3500000, 3500000},
 #endif
 #ifdef B4000000
-                  {B4000000, 4000000},
+          {B4000000, 4000000},
 #endif
 
-                  /* MacOS extensions */
+          /* MacOS extensions */
 #ifdef B7200
-                  {B7200, 7200},
+          {B7200, 7200},
 #endif
 #ifdef B14400
-                  {B14400, 14400},
+          {B14400, 14400},
 #endif
 #ifdef B28800
-                  {B28800, 28800},
+          {B28800, 28800},
 #endif
 #ifdef B76800
-                  {B76800, 76800},
+          {B76800, 76800},
 #endif
 
   /* Cygwin extensions (in addition to the Linux ones) */
 #ifdef B128000
-                  {B128000, 128000},
+          {B128000, 128000},
 #endif
 #ifdef B256000
-                  {B256000, 256000},
+          {B256000, 256000},
 #endif
-};
+  };
 
-#define NSPEEDS (sizeof(speedtable) / sizeof(speedtable[0]))
+  if (dst != NULL) memcpy(dst, speedtable, sizeof(speedtable));
+  return (sizeof(speedtable) / sizeof(speedtable[0]));
+}
 
-static tcflag_t *choose_field(struct termios *terminal_status, long field)
-{
-    switch (field) {
-        case Iflags:
-            return &terminal_status->c_iflag;
-        case Oflags:
-            return &terminal_status->c_oflag;
-        case Cflags:
-            return &terminal_status->c_cflag;
-        case Lflags:
-            return &terminal_status->c_lflag;
-        default:
-            return 0;
-    }
+long _terminal_io_descr(long dst[]) {
+  long terminal_io_descr[] = {
+      /* Input modes */
+      Bool, Iflags, IGNBRK, Bool, Iflags, BRKINT, Bool, Iflags, IGNPAR, Bool,
+      Iflags, PARMRK, Bool, Iflags, INPCK, Bool, Iflags, ISTRIP, Bool, Iflags,
+      INLCR, Bool, Iflags, IGNCR, Bool, Iflags, ICRNL, Bool, Iflags, IXON, Bool,
+      Iflags, IXOFF,
+      /* Output modes */
+      Bool, Oflags, OPOST,
+      /* Control modes */
+      Speed, Output, Speed, Input, Enum, Cflags, 5, 4, CSIZE, CS5, CS6, CS7, CS8,
+      Enum, Cflags, 1, 2, CSTOPB, 0, CSTOPB, Bool, Cflags, CREAD, Bool, Cflags,
+      PARENB, Bool, Cflags, PARODD, Bool, Cflags, HUPCL, Bool, Cflags, CLOCAL,
+      /* Local modes */
+      Bool, Lflags, ISIG, Bool, Lflags, ICANON, Bool, Lflags, NOFLSH, Bool,
+      Lflags, ECHO, Bool, Lflags, ECHOE, Bool, Lflags, ECHOK, Bool, Lflags,
+      ECHONL,
+      /* Control characters */
+      Char, VINTR, Char, VQUIT, Char, VERASE, Char, VKILL, Char, VEOF, Char, VEOL,
+      Char, VMIN, Char, VTIME, Char, VSTART, Char, VSTOP, End};
+
+  if (dst != NULL) memcpy(dst, terminal_io_descr, sizeof(terminal_io_descr));
+  return (sizeof(terminal_io_descr) / sizeof(long));
 }
 
+
 void encode_terminal_status(struct termios *terminal_status, value *dst)
 {
     long *pc;
     int i;
 
+    long _NSPEEDS = _speedtable(NULL);
+    struct speed_t speedtable[_NSPEEDS];
+    _speedtable(speedtable);
+
+    long nterminal_io_descr = _terminal_io_descr(NULL);
+    long terminal_io_descr[nterminal_io_descr];
+    _terminal_io_descr(terminal_io_descr);
+
     for (pc = terminal_io_descr; *pc != End; dst++) {
         switch (*pc++) {
             case Bool: {
@@ -190,7 +210,7 @@ void encode_terminal_status(struct termios *terminal_status, value *dst)
                         speed = cfgetispeed(terminal_status);
                         break;
                 }
-                for (i = 0; i < NSPEEDS; i++) {
+                for (i = 0; i < _NSPEEDS; i++) {
                     if (speed == speedtable[i].speed) {
                         *dst = Val_int(speedtable[i].baud);
                         break;
@@ -212,6 +232,14 @@ int decode_terminal_status(struct termios *terminal_status, value *src)
     long *pc;
     int i;
 
+    long _NSPEEDS = _speedtable(NULL);
+    struct speed_t speedtable[_NSPEEDS];
+    _speedtable(speedtable);
+
+    long nterminal_io_descr = _terminal_io_descr(NULL);
+    long terminal_io_descr[nterminal_io_descr];
+    _terminal_io_descr(terminal_io_descr);
+
     for (pc = terminal_io_descr; *pc != End; src++) {
         switch (*pc++) {
             case Bool: {
@@ -242,7 +270,7 @@ int decode_terminal_status(struct termios *terminal_status, value *src)
                 int which = *pc++;
                 int baud = Int_val(*src);
                 int res = 0;
-                for (i = 0; i < NSPEEDS; i++) {
+                for (i = 0; i < _NSPEEDS; i++) {
                     if (baud == speedtable[i].baud) {
                         switch (which) {
                             case Output:
