PERFORCE change 95571 for review

[John Birrell]

http://perforce.freebsd.org/chv.cgi?CH=95571

Change 95571 by jb at jb_freebsd2 on 2006/04/19 02:17:03

	This code is nature's way of reminding me that I'm no lex whiz.
	
	The OpenSolaris code expects AT&T (SCO? Ugh) semantics. That means non-POSIX.
	Sigh.
	
	FreeBSD uses 'flex' as 'lex', so we turn on compatibility mode for as much as
	possible, but that still doesn't let us redefine input(). We have to define
	YY_INPUT, but this works ahead of time, buffering as many characters as
	possible for performance reasons. As a result, we can't check the states that
	the Solaris version does on a character by character basis.
	
	This at least lets us initialise dtrace(1) now. It now wants to know about
	providers, so we're heading in the right direction.

Affected files ...

.. //depot/projects/dtrace/src/contrib/opensolaris/lib/libdtrace/common/dt_lex.l#3 edit

Differences ...

==== //depot/projects/dtrace/src/contrib/opensolaris/lib/libdtrace/common/dt_lex.l#3 (text) ====

@@ -46,13 +46,34 @@
 #undef input
 #undef unput
 #else
-#undef yyinput
-#define yyinput input
+/* 
+ * Define YY_INPUT for flex since input() can't be re-defined.
+ */
+#define YY_INPUT(buf,result,max_size) \
+	if (yypcb->pcb_fileptr != NULL) { \
+		int n; \
+		for (n = 0; n < max_size && \
+		    ferror(yypcb->pcb_fileptr) == 0; n++) { \
+			int c = fgetc(yypcb->pcb_fileptr); \
+			if (c == EOF) \
+				break; \
+			buf[n] = c; \
+		} \
+		if (yypcb->pcb_fileptr != NULL && ferror(yypcb->pcb_fileptr)) \
+			longjmp(yypcb->pcb_jmpbuf, EDT_FIO); \
+		return n; \
+	} else { \
+		int n; \
+		for (n = 0; n < max_size && \
+		    yypcb->pcb_strptr < yypcb->pcb_string + yypcb->pcb_strlen; n++) \
+			buf[n] = *yypcb->pcb_strptr++; \
+		result = n; \
+	}
 #endif
 
 static int id_or_type(const char *);
+#if defined(sun)
 static int input(void);
-#if defined(sun)
 static void unput(int);
 #endif
 
@@ -794,17 +815,15 @@
 	return (ttok);
 }
 
+#if defined(sun)
 static int
-dtinput(void)
+input(void)
 {
 	int c;
 
-#if defined(sun)
 	if (yysptr > yysbuf)
 		c = *--yysptr;
-	else
-#endif
-	if (yypcb->pcb_fileptr != NULL)
+	else if (yypcb->pcb_fileptr != NULL)
 		c = fgetc(yypcb->pcb_fileptr);
 	else if (yypcb->pcb_strptr < yypcb->pcb_string + yypcb->pcb_strlen)
 		c = *yypcb->pcb_strptr++;
@@ -829,7 +848,6 @@
 	return (0); /* EOF */
 }
 
-#if defined(sun)
 static void
 unput(int c)
 {