1 files changed, 404 insertions, 0 deletions

diff --git a/src/libvterm/src/parser.c b/src/libvterm/src/parser.c
new file mode 100644
index 0000000..0d1e12b
--- /dev/null
+++ b/src/libvterm/src/parser.c
@@ -0,0 +1,404 @@
+#include "vterm_internal.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#undef DEBUG_PARSER
+
+static int is_intermed(unsigned char c)
+{
+  return c >= 0x20 && c <= 0x2f;
+}
+
+static void do_control(VTerm *vt, unsigned char control)
+{
+  if(vt->parser.callbacks && vt->parser.callbacks->control)
+    if((*vt->parser.callbacks->control)(control, vt->parser.cbdata))
+      return;
+
+  DEBUG_LOG1("libvterm: Unhandled control 0x%02x\n", control);
+}
+
+static void do_csi(VTerm *vt, char command)
+{
+#ifdef DEBUG_PARSER
+  printf("Parsed CSI args as:\n", arglen, args);
+  printf(" leader: %s\n", vt->parser.v.csi.leader);
+  for(int argi = 0; argi < vt->parser.v.csi.argi; argi++) {
+    printf(" %lu", CSI_ARG(vt->parser.v.csi.args[argi]));
+    if(!CSI_ARG_HAS_MORE(vt->parser.v.csi.args[argi]))
+      printf("\n");
+  printf(" intermed: %s\n", vt->parser.intermed);
+  }
+#endif
+
+  if(vt->parser.callbacks && vt->parser.callbacks->csi)
+    if((*vt->parser.callbacks->csi)(
+          vt->parser.v.csi.leaderlen ? vt->parser.v.csi.leader : NULL,
+          vt->parser.v.csi.args,
+          vt->parser.v.csi.argi,
+          vt->parser.intermedlen ? vt->parser.intermed : NULL,
+          command,
+          vt->parser.cbdata))
+      return;
+
+  DEBUG_LOG1("libvterm: Unhandled CSI %c\n", command);
+}
+
+static void do_escape(VTerm *vt, char command)
+{
+  char seq[INTERMED_MAX+1];
+
+  size_t len = vt->parser.intermedlen;
+  strncpy(seq, vt->parser.intermed, len);
+  seq[len++] = command;
+  seq[len]   = 0;
+
+  if(vt->parser.callbacks && vt->parser.callbacks->escape)
+    if((*vt->parser.callbacks->escape)(seq, len, vt->parser.cbdata))
+      return;
+
+  DEBUG_LOG1("libvterm: Unhandled escape ESC 0x%02x\n", command);
+}
+
+static void string_fragment(VTerm *vt, const char *str, size_t len, int final)
+{
+  VTermStringFragment frag;
+
+  frag.str = str;
+  frag.len = len;
+  frag.initial = vt->parser.string_initial;
+  frag.final = final;
+
+  switch(vt->parser.state) {
+    case OSC:
+      if(vt->parser.callbacks && vt->parser.callbacks->osc)
+        (*vt->parser.callbacks->osc)(vt->parser.v.osc.command, frag, vt->parser.cbdata);
+      break;
+
+    case DCS:
+      if(vt->parser.callbacks && vt->parser.callbacks->dcs)
+        (*vt->parser.callbacks->dcs)(vt->parser.v.dcs.command, vt->parser.v.dcs.commandlen, frag, vt->parser.cbdata);
+      break;
+
+    case APC:
+      if(vt->parser.callbacks && vt->parser.callbacks->apc)
+        (*vt->parser.callbacks->apc)(frag, vt->parser.cbdata);
+      break;
+
+    case PM:
+      if(vt->parser.callbacks && vt->parser.callbacks->pm)
+        (*vt->parser.callbacks->pm)(frag, vt->parser.cbdata);
+      break;
+
+    case SOS:
+      if(vt->parser.callbacks && vt->parser.callbacks->sos)
+        (*vt->parser.callbacks->sos)(frag, vt->parser.cbdata);
+      break;
+
+    case NORMAL:
+    case CSI_LEADER:
+    case CSI_ARGS:
+    case CSI_INTERMED:
+    case OSC_COMMAND:
+    case DCS_COMMAND:
+      break;
+  }
+
+  vt->parser.string_initial = FALSE;
+}
+
+size_t vterm_input_write(VTerm *vt, const char *bytes, size_t len)
+{
+  size_t pos = 0;
+  const char *string_start = NULL;  // init to avoid gcc warning
+
+  vt->in_backspace = 0;		    // Count down with BS key and activate when
+				    // it reaches 1
+
+  switch(vt->parser.state) {
+  case NORMAL:
+  case CSI_LEADER:
+  case CSI_ARGS:
+  case CSI_INTERMED:
+  case OSC_COMMAND:
+  case DCS_COMMAND:
+    string_start = NULL;
+    break;
+  case OSC:
+  case DCS:
+  case APC:
+  case PM:
+  case SOS:
+    string_start = bytes;
+    break;
+  }
+
+#define ENTER_STATE(st)        do { vt->parser.state = st; string_start = NULL; } while(0)
+#define ENTER_NORMAL_STATE()   ENTER_STATE(NORMAL)
+
+#define IS_STRING_STATE()      (vt->parser.state >= OSC_COMMAND)
+
+  for( ; pos < len; pos++) {
+    unsigned char c = bytes[pos];
+    int c1_allowed = !vt->mode.utf8;
+
+    if(c == 0x00 || c == 0x7f) { // NUL, DEL
+      if(IS_STRING_STATE()) {
+        string_fragment(vt, string_start, bytes + pos - string_start, FALSE);
+        string_start = bytes + pos + 1;
+      }
+      continue;
+    }
+    if(c == 0x18 || c == 0x1a) { // CAN, SUB
+      vt->parser.in_esc = FALSE;
+      ENTER_NORMAL_STATE();
+      continue;
+    }
+    else if(c == 0x1b) { // ESC
+      vt->parser.intermedlen = 0;
+      if(!IS_STRING_STATE())
+        vt->parser.state = NORMAL;
+      vt->parser.in_esc = TRUE;
+      continue;
+    }
+    else if(c == 0x07 &&  // BEL, can stand for ST in OSC or DCS state
+            IS_STRING_STATE()) {
+      // fallthrough
+    }
+    else if(c < 0x20) { // other C0
+      if(vt->parser.state == SOS)
+        continue; // All other C0s permitted in SOS
+
+      if(vterm_get_special_pty_type() == 2) {
+        if(c == 0x08) // BS
+          // Set the trick for BS output after a sequence, to delay backspace
+          // activation
+          if(pos + 2 < len && bytes[pos + 1] == 0x20 && bytes[pos + 2] == 0x08)
+            vt->in_backspace = 2; // Trigger when count down to 1
+      }
+      if(IS_STRING_STATE())
+        string_fragment(vt, string_start, bytes + pos - string_start, FALSE);
+      do_control(vt, c);
+      if(IS_STRING_STATE())
+        string_start = bytes + pos + 1;
+      continue;
+    }
+    // else fallthrough
+
+    size_t string_len = bytes + pos - string_start;
+
+    if(vt->parser.in_esc) {
+      // Hoist an ESC letter into a C1 if we're not in a string mode
+      // Always accept ESC \ == ST even in string mode
+      if(!vt->parser.intermedlen &&
+          c >= 0x40 && c < 0x60 &&
+          ((!IS_STRING_STATE() || c == 0x5c))) {
+        c += 0x40;
+        c1_allowed = TRUE;
+        if(string_len)
+          string_len -= 1;
+        vt->parser.in_esc = FALSE;
+      }
+      else {
+        string_start = NULL;
+        vt->parser.state = NORMAL;
+      }
+    }
+
+    switch(vt->parser.state) {
+    case CSI_LEADER:
+      /* Extract leader bytes 0x3c to 0x3f */
+      if(c >= 0x3c && c <= 0x3f) {
+        if(vt->parser.v.csi.leaderlen < CSI_LEADER_MAX-1)
+          vt->parser.v.csi.leader[vt->parser.v.csi.leaderlen++] = c;
+        break;
+      }
+
+      /* else fallthrough */
+      vt->parser.v.csi.leader[vt->parser.v.csi.leaderlen] = 0;
+
+      vt->parser.v.csi.argi = 0;
+      vt->parser.v.csi.args[0] = CSI_ARG_MISSING;
+      vt->parser.state = CSI_ARGS;
+
+      /* fallthrough */
+    case CSI_ARGS:
+      /* Numerical value of argument */
+      if(c >= '0' && c <= '9') {
+        if(vt->parser.v.csi.args[vt->parser.v.csi.argi] == CSI_ARG_MISSING)
+          vt->parser.v.csi.args[vt->parser.v.csi.argi] = 0;
+        vt->parser.v.csi.args[vt->parser.v.csi.argi] *= 10;
+        vt->parser.v.csi.args[vt->parser.v.csi.argi] += c - '0';
+        break;
+      }
+      if(c == ':') {
+        vt->parser.v.csi.args[vt->parser.v.csi.argi] |= CSI_ARG_FLAG_MORE;
+        c = ';';
+      }
+      if(c == ';') {
+        vt->parser.v.csi.argi++;
+        vt->parser.v.csi.args[vt->parser.v.csi.argi] = CSI_ARG_MISSING;
+        break;
+      }
+
+      /* else fallthrough */
+      vt->parser.v.csi.argi++;
+      vt->parser.intermedlen = 0;
+      vt->parser.state = CSI_INTERMED;
+      // FALLTHROUGH
+    case CSI_INTERMED:
+      if(is_intermed(c)) {
+        if(vt->parser.intermedlen < INTERMED_MAX-1)
+          vt->parser.intermed[vt->parser.intermedlen++] = c;
+        break;
+      }
+      else if(c == 0x1b) {
+        /* ESC in CSI cancels */
+      }
+      else if(c >= 0x40 && c <= 0x7e) {
+        vt->parser.intermed[vt->parser.intermedlen] = 0;
+        do_csi(vt, c);
+      }
+      /* else was invalid CSI */
+
+      ENTER_NORMAL_STATE();
+      break;
+
+    case OSC_COMMAND:
+      /* Numerical value of command */
+      if(c >= '0' && c <= '9') {
+        if(vt->parser.v.osc.command == -1)
+          vt->parser.v.osc.command = 0;
+        else
+          vt->parser.v.osc.command *= 10;
+        vt->parser.v.osc.command += c - '0';
+        break;
+      }
+      if(c == ';') {
+        vt->parser.state = OSC;
+        string_start = bytes + pos + 1;
+        break;
+      }
+
+      /* else fallthrough */
+      string_start = bytes + pos;
+      string_len   = 0;
+      vt->parser.state = OSC;
+      goto string_state;
+
+    case DCS_COMMAND:
+      if(vt->parser.v.dcs.commandlen < CSI_LEADER_MAX)
+        vt->parser.v.dcs.command[vt->parser.v.dcs.commandlen++] = c;
+
+      if(c >= 0x40 && c<= 0x7e) {
+        string_start = bytes + pos + 1;
+        vt->parser.state = DCS;
+      }
+      break;
+
+string_state:
+    case OSC:
+    case DCS:
+    case APC:
+    case PM:
+    case SOS:
+      if(c == 0x07 || (c1_allowed && c == 0x9c)) {
+        string_fragment(vt, string_start, string_len, TRUE);
+        ENTER_NORMAL_STATE();
+      }
+      break;
+
+    case NORMAL:
+      if(vt->parser.in_esc) {
+        if(is_intermed(c)) {
+          if(vt->parser.intermedlen < INTERMED_MAX-1)
+            vt->parser.intermed[vt->parser.intermedlen++] = c;
+        }
+        else if(c >= 0x30 && c < 0x7f) {
+          do_escape(vt, c);
+          vt->parser.in_esc = 0;
+          ENTER_NORMAL_STATE();
+        }
+        else {
+          DEBUG_LOG1("TODO: Unhandled byte %02x in Escape\n", c);
+        }
+        break;
+      }
+      if(c1_allowed && c >= 0x80 && c < 0xa0) {
+        switch(c) {
+        case 0x90: // DCS
+          vt->parser.string_initial = TRUE;
+          vt->parser.v.dcs.commandlen = 0;
+          ENTER_STATE(DCS_COMMAND);
+          break;
+        case 0x98: // SOS
+          vt->parser.string_initial = TRUE;
+          ENTER_STATE(SOS);
+          string_start = bytes + pos + 1;
+          string_len = 0;
+          break;
+        case 0x9b: // CSI
+          vt->parser.v.csi.leaderlen = 0;
+          ENTER_STATE(CSI_LEADER);
+          break;
+        case 0x9d: // OSC
+          vt->parser.v.osc.command = -1;
+          vt->parser.string_initial = TRUE;
+          string_start = bytes + pos + 1;
+          ENTER_STATE(OSC_COMMAND);
+          break;
+        case 0x9e: // PM
+          vt->parser.string_initial = TRUE;
+          ENTER_STATE(PM);
+          string_start = bytes + pos + 1;
+          string_len = 0;
+          break;
+        case 0x9f: // APC
+          vt->parser.string_initial = TRUE;
+          ENTER_STATE(APC);
+          string_start = bytes + pos + 1;
+          string_len = 0;
+          break;
+        default:
+          do_control(vt, c);
+          break;
+        }
+      }
+      else {
+        size_t eaten = 0;
+        if(vt->parser.callbacks && vt->parser.callbacks->text)
+          eaten = (*vt->parser.callbacks->text)(bytes + pos, len - pos, vt->parser.cbdata);
+
+        if(!eaten) {
+          DEBUG_LOG("libvterm: Text callback did not consume any input\n");
+          /* force it to make progress */
+          eaten = 1;
+        }
+
+        pos += (eaten - 1); // we'll ++ it again in a moment
+      }
+      break;
+    }
+  }
+
+  if(string_start) {
+    size_t string_len = bytes + pos - string_start;
+    if(vt->parser.in_esc)
+      string_len -= 1;
+    string_fragment(vt, string_start, string_len, FALSE);
+  }
+
+  return len;
+}
+
+void vterm_parser_set_callbacks(VTerm *vt, const VTermParserCallbacks *callbacks, void *user)
+{
+  vt->parser.callbacks = callbacks;
+  vt->parser.cbdata = user;
+}
+
+void *vterm_parser_get_cbdata(VTerm *vt)
+{
+  return vt->parser.cbdata;
+}