Readded files.

[splint.git] / src / scan.c

diff --git a/src/scan.c b/src/scan.c
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+/*
+** LCLint - annotation-assisted static program checker
+** Copyright (C) 1994-2000 University of Virginia,
+**         Massachusetts Institute of Technology
+**
+** This program is free software; you can redistribute it and/or modify it
+** under the terms of the GNU General Public License as published by the
+** Free Software Foundation; either version 2 of the License, or (at your
+** option) any later version.
+** 
+** This program is distributed in the hope that it will be useful, but
+** WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+** General Public License for more details.
+** 
+** The GNU General Public License is available from http://www.gnu.org/ or
+** the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+** MA 02111-1307, USA.
+**
+** For information on lclint: lclint-request@cs.virginia.edu
+** To report a bug: lclint-bug@cs.virginia.edu
+** For more information: http://lclint.cs.virginia.edu
+*/
+/*
+** scan.c
+**
+** Deliver tokens one at a time
+**
+**     METHOD:
+**     The input arrives via LSLScanFreshToken ().
+**     The output is reported via LSLScanNextToken ().
+**
+**     The tokens are built in module ScanLine.
+**     The tokens are delivered from this module.
+**     Meantimes, they are saved in a static array.
+**
+**     The tokenizing is split off from the delivery of tokens
+**     to facilitate incremental scanning at a later date.
+**     The essential is that scanline () can be called or not
+**     if the input text is dirty or not.  Clean lines cause
+**     tokens to be played out from the saved token list (not
+**     yet implemented in this version).
+*/
+
+# include "lclintMacros.nf"
+# include "llbasic.h"
+# include "signature.h"
+# include "signature2.h"
+# include "scan.h"
+# include "scanline.h"
+
+extern /*@external@*/ /*@unused@*/ YYSTYPE lsllval;
+
+static /*@exposed@*/ ltoken LSLScanLookAhead (void);
+static tsource *scanFile;        /* file to scan */
+static o_ltoken TokenList[MAXLINE]; /* available tokens */
+static int nextToken;            /* next available token */
+static int lastToken;            /* next available slot */
+
+static /*@dependent@*/ /*@null@*/ char *line;  /* input text */
+static unsigned int lineNumber;        /* current line number */
+
+unsigned int lsllex (YYSTYPE *lval)
+{
+  /* This is important!  Bison expects this */
+  lval->ltok = LSLScanNextToken ();
+  return (ltoken_getCode (lval->ltok));
+}
+
+ltoken LSLScanNextToken (void)
+{
+  
+  if (nextToken < lastToken)
+    {  
+      /*@-retalias@*/
+            return TokenList[nextToken++];
+      /*@=retalias@*/
+    }
+  else
+    {
+      lastToken = 0;           
+      lineNumber++;
+
+      line = tsource_nextLine (scanFile);       
+      
+      if (line != (char *) 0)
+       {
+                 lscanLine (line);     /* tokenize */
+         nextToken = 0;
+         return LSLScanNextToken ();   
+       }
+      else
+       {
+                 return LSLScanEofToken ();
+       }
+    }
+}
+
+static /*@exposed@*/ ltoken
+LSLScanLookAhead (void)
+{
+  if (nextToken < lastToken)
+    {          
+      return TokenList[nextToken];
+    }
+  else
+    {
+      lastToken = 0;           
+      line = tsource_nextLine (scanFile);
+
+      if (line != (char *) 0)
+       {
+         lscanLine (line);     
+         nextToken = 0;        
+         return LSLScanLookAhead ();   
+       }
+      else
+       {
+         /* 
+          ** This is a real memory leak.  Its only a few bytes
+         ** per file though, and lsl files are hardly ever used.
+         */
+
+         /*@-onlytrans@*/ 
+         return LSLScanEofToken ();
+         /*@=onlytrans@*/
+       }
+    }
+}
+
+void
+LSLScanFreshToken (ltoken tok)
+{
+  if (lastToken < MAXLINE)
+    {                          
+      TokenList[lastToken++] = ltoken_copy (tok);      
+    }
+  else
+    {
+      llfatalbug (message ("LSLScanFreshToken: out of range: %s", 
+                          cstring_fromChars (lsymbol_toChars (ltoken_getText (tok)))));
+    }
+}
+
+/*@exposed@*/ tsource *LSLScanSource (void)
+{
+  return scanFile;
+}
+
+
+void
+LSLScanInit (void)
+{
+}
+
+void
+LSLScanReset (tsource *s)
+{
+  scanFile = s;
+  lastToken = 0;
+  nextToken = lastToken + 1;   /* force call to scanline   */
+  lineNumber = 0;
+}
+
+void
+LSLScanCleanup (void)
+{
+}