o Add proper stack checking to all file words

o add fkey and fread
o eliminate fexists now that this can be expressed in HLL forth
  ( : fexists fopen dup -1 <> if fclose 1 else drop 0 then ; ) :-)

Once we get the ability to write files, it should be possible to do
stand-alone rescue work from the 3rd stage boot. :)

1 files changed, 48 insertions, 28 deletions

diff --git a/sys/boot/ficl/words.c b/sys/boot/ficl/words.c
index 4af3f0e..b92d691 100644
--- a/sys/boot/ficl/words.c
+++ b/sys/boot/ficl/words.c
@@ -4030,6 +4030,9 @@ static void pfopen(FICL_VM *pVM)
     int     fd;
     char    *p;
 
+#if FICL_ROBUST > 1
+    vmCheckStack(pVM, 2, 1);
+#endif
     (void)stackPopINT32(pVM->pStack); /* don't need count value */
     p = stackPopPtr(pVM->pStack);
     fd = open(p, O_RDONLY);
@@ -4045,44 +4048,51 @@ static void pfclose(FICL_VM *pVM)
 {
     int fd;
 
+#if FICL_ROBUST > 1
+    vmCheckStack(pVM, 1, 0);
+#endif
     fd = stackPopINT32(pVM->pStack); /* get fd */
     if (fd != -1)
 	close(fd);
     return;
 }
 
-/*          fload - interpret file contents
+/*          fread - read file contents
  *
- * fload  ( fd -- )
+ * fread  ( fd buf nbytes  -- nread )
  */
-static void pfload(FICL_VM *pVM)
+static void pfread(FICL_VM *pVM)
 {
-    int     fd;
+    int     fd, len;
+    char *buf;
 
+#if FICL_ROBUST > 1
+    vmCheckStack(pVM, 3, 1);
+#endif
+    len = stackPopINT32(pVM->pStack); /* get number of bytes to read */
+    buf = stackPopPtr(pVM->pStack); /* get buffer */
     fd = stackPopINT32(pVM->pStack); /* get fd */
-    if (fd != -1)
-	ficlExecFD(pVM, fd);
+    if (len > 0 && buf && fd != -1)
+	stackPushINT32(pVM->pStack, read(fd, buf, len));
+    else
+	stackPushINT32(pVM->pStack, -1);
     return;
 }
 
-/*          fexists - check to see if file exists, returning TRUE or FALSE
+/*          fload - interpret file contents
  *
- * fexists  ( count ptr -- bool )
+ * fload  ( fd -- )
  */
-static void pfexists(FICL_VM *pVM)
+static void pfload(FICL_VM *pVM)
 {
-    char    *p;
     int     fd;
 
-    (void)stackPopINT32(pVM->pStack); /* don't need count value */
-    p = stackPopPtr(pVM->pStack);
-    fd = open(p, O_RDONLY);
-    if (fd > 0) {
-	stackPushINT32(pVM->pStack, TRUE);
-	close(fd);
-    }
-    else
-	stackPushINT32(pVM->pStack, FALSE);
+#if FICL_ROBUST > 1
+    vmCheckStack(pVM, 1, 0);
+#endif
+    fd = stackPopINT32(pVM->pStack); /* get fd */
+    if (fd != -1)
+	ficlExecFD(pVM, fd);
     return;
 }
 
@@ -4092,23 +4102,32 @@ static void pfexists(FICL_VM *pVM)
  */
 static void key(FICL_VM *pVM)
 {
+#if FICL_ROBUST > 1
+    vmCheckStack(pVM, 0, 1);
+#endif
     stackPushINT32(pVM->pStack, getchar());
     return;
 }
 
-#if 0
-/**************************************************************************
-
-** 
-**************************************************************************/
-static void funcname(FICL_VM *pVM)
+/*           fkey - get a character from a file
+ *
+ * fkey ( file -- char )
+ */
+static void fkey(FICL_VM *pVM)
 {
-    IGNORE(pVM);
+    int i, fd;
+    char ch;
+
+#if FICL_ROBUST > 1
+    vmCheckStack(pVM, 1, 1);
+#endif
+    fd = stackPopINT32(pVM->pStack);
+    i = read(fd, &ch, 1);
+    stackPushINT32(pVM->pStack, i > 0 ? ch : -1);
     return;
 }
 
 
-#endif
 /**************************************************************************
                         f i c l C o m p i l e C o r e
 ** Builds the primitive wordset and the environment-query namespace.
@@ -4271,10 +4290,11 @@ void ficlCompileCore(FICL_DICT *dp)
     dictAppendWord(dp, "\\",        commentLine,    FW_IMMEDIATE);
 
     /* FreeBSD extention words */
-    dictAppendWord(dp, "fexists",   pfexists,	    FW_DEFAULT);
     dictAppendWord(dp, "fopen",	    pfopen,	    FW_DEFAULT);
     dictAppendWord(dp, "fclose",    pfclose,	    FW_DEFAULT);
+    dictAppendWord(dp, "fread",	    pfread,	    FW_DEFAULT);
     dictAppendWord(dp, "fload",	    pfload,	    FW_DEFAULT);
+    dictAppendWord(dp, "fkey",	    fkey,	    FW_DEFAULT);
     dictAppendWord(dp, "key",	    key,	    FW_DEFAULT);
 
     /*