X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flanguage%2Flexer%2Fsegment.c;h=5f7fc01310d4241288b39d038ceb1294c25c46f6;hb=ed109bf498216cef15a3cbf180827dc8b20eff0b;hp=c0a09973ce8059535ea7c1e487c5fa2016ff8134;hpb=e0f9210e814d03bc43b6a9b30a402e403d5666b9;p=pspp

diff --git a/src/language/lexer/segment.c b/src/language/lexer/segment.c
index c0a09973ce..5f7fc01310 100644
--- a/src/language/lexer/segment.c
+++ b/src/language/lexer/segment.c
@@ -92,21 +92,26 @@ segmenter_parse_shbang__ (struct segmenter *s, const char *input, size_t n,
         {
           if (input[1] == '!')
             {
-              int ofs;
-
-              for (ofs = 2; ofs < n; ofs++)
-                if (input[ofs] == '\n')
-                  {
-                    if (input[ofs] == '\n' && input[ofs - 1] == '\r')
-                      ofs--;
-
-                    s->state = S_GENERAL;
-                    s->substate = SS_START_OF_COMMAND;
-                    *type = SEG_SHBANG;
-                    return ofs;
-                  }
+              for (int ofs = 2; ; ofs++)
+                {
+                  if (ofs >= n)
+                    {
+                      if (!eof)
+                        return -1;
+                    }
+                  else if (input[ofs] == '\n')
+                    {
+                      if (input[ofs - 1] == '\r')
+                        ofs--;
+                    }
+                  else
+                    continue;
 
-              return eof ? ofs : -1;
+                  s->state = S_GENERAL;
+                  s->substate = SS_START_OF_COMMAND;
+                  *type = SEG_SHBANG;
+                  return ofs;
+                }
             }
         }
       else if (!eof)
@@ -281,20 +286,23 @@ segmenter_parse_number__ (struct segmenter *s, const char *input, size_t n,
       if (!eof)
         return -1;
       goto number;
-    };
+    }
   if (input[ofs] == '.')
     {
+      if (ofs + 1 >= n)
+        {
+          if (!eof)
+            return -1;
+          goto number;
+        }
+
       ofs = skip_digits (input, n, eof, ofs + 1);
       if (ofs < 0)
         return -1;
+      else if (ofs >= n)
+        goto number;
     }
 
-  if (ofs >= n)
-    {
-      if (!eof)
-        return -1;
-      goto number;
-    }
   if (input[ofs] == 'e' || input[ofs] == 'E')
     {
       ofs++;
@@ -643,6 +651,7 @@ next_id_in_command (const struct segmenter *s, const char *input, size_t n,
             }
           /* fall through */
 
+        case SEG_MACRO_ID:
         case SEG_NUMBER:
         case SEG_QUOTED_STRING:
         case SEG_HEX_STRING:
@@ -711,10 +720,9 @@ segmenter_parse_id__ (struct segmenter *s, const char *input, size_t n,
         ofs--;
     }
 
-  if (is_reserved_word (input, ofs))
-    *type = SEG_RESERVED_WORD;
-  else
-    *type = SEG_IDENTIFIER;
+  *type = (is_reserved_word (input, ofs) ? SEG_RESERVED_WORD
+           : input[0] == '!' ? SEG_MACRO_ID
+           : SEG_IDENTIFIER);
 
   if (s->substate & SS_START_OF_COMMAND)
     {
@@ -981,6 +989,9 @@ segmenter_parse_mid_command__ (struct segmenter *s,
       return segmenter_parse_string__ (SEG_QUOTED_STRING, 0,
                                        s, input, n, eof, type);
 
+    case '!':
+      return segmenter_parse_id__ (s, input, n, eof, type);
+
     default:
       if (lex_uc_is_space (uc))
         {
@@ -1004,6 +1015,12 @@ segmenter_parse_mid_command__ (struct segmenter *s,
         }
       else if (lex_uc_is_id1 (uc))
         return segmenter_parse_id__ (s, input, n, eof, type);
+      else if (uc > 32 && uc < 127 && uc != '\\' && uc != '^')
+        {
+          *type = SEG_PUNCT;
+          s->substate = 0;
+          return 1;
+        }
       else
         {
           *type = SEG_UNEXPECTED_CHAR;
@@ -1269,6 +1286,9 @@ segmenter_subparse (struct segmenter *s,
   return ofs;
 }
 
+/* We are segmenting a DO REPEAT command, currently reading the syntax that
+   defines the stand-in variables (the head) before the lines of syntax to be
+   repeated (the body). */
 static int
 segmenter_parse_do_repeat_1__ (struct segmenter *s,
                                const char *input, size_t n, bool eof,
@@ -1278,10 +1298,14 @@ segmenter_parse_do_repeat_1__ (struct segmenter *s,
   if (ofs < 0)
     return -1;
 
-  if (*type == SEG_START_COMMAND || *type == SEG_SEPARATE_COMMANDS)
-    s->state = S_DO_REPEAT_2;
-  else if (*type == SEG_END_COMMAND)
+  if (*type == SEG_SEPARATE_COMMANDS)
     {
+      /* We reached a blank line that separates the head from the body. */
+      s->state = S_DO_REPEAT_2;
+    }
+  else if (*type == SEG_END_COMMAND || *type == SEG_START_COMMAND)
+    {
+      /* We reached the body. */
       s->state = S_DO_REPEAT_3;
       s->substate = 1;
     }
@@ -1289,6 +1313,8 @@ segmenter_parse_do_repeat_1__ (struct segmenter *s,
   return ofs;
 }
 
+/* We are segmenting a DO REPEAT command, currently reading a blank line that
+   separates the head from the body. */
 static int
 segmenter_parse_do_repeat_2__ (struct segmenter *s,
                                const char *input, size_t n, bool eof,
@@ -1300,6 +1326,7 @@ segmenter_parse_do_repeat_2__ (struct segmenter *s,
 
   if (*type == SEG_NEWLINE)
     {
+      /* We reached the body. */
       s->state = S_DO_REPEAT_3;
       s->substate = 1;
     }
@@ -1356,6 +1383,12 @@ segmenter_parse_full_line__ (const char *input, size_t n, bool eof,
     return ofs - (input[ofs - 1] == '\r');
 }
 
+/* We are in the body of DO REPEAT, segmenting the lines of syntax that are to
+   be repeated.  Report each line of syntax as a single SEG_DO_REPEAT_COMMAND.
+
+   DO REPEAT can be nested, so we look for DO REPEAT...END REPEAT blocks inside
+   the lines we're segmenting.  s->substate counts the nesting level, starting
+   at 1. */
 static int
 segmenter_parse_do_repeat_3__ (struct segmenter *s,
                                const char *input, size_t n, bool eof,
@@ -1370,6 +1403,8 @@ segmenter_parse_do_repeat_3__ (struct segmenter *s,
     return -1;
   else if (s->substate == 0)
     {
+      /* Nesting level dropped to 0, so we've finished reading the DO REPEAT
+         body. */
       s->state = S_GENERAL;
       s->substate = SS_START_OF_COMMAND | SS_START_OF_LINE;
       return segmenter_push (s, input, n, eof, type);