Skip site navigation (1)Skip section navigation (2) 
Date:      Mon, 27 Dec 2010 22:18:27 +0000 (UTC)
From:      Jilles Tjoelker <jilles@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r216743 - head/bin/sh
Message-ID:  <201012272218.oBRMIRct038088@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help 
Author: jilles
Date: Mon Dec 27 22:18:27 2010
New Revision: 216743
URL: http://svn.freebsd.org/changeset/base/216743

Log:
  sh: Simplify "stack string" code slightly.
  
  Maintain a pointer to the end of the stack string area instead of how much
  space is left. This simplifies the macros in memalloc.h. The places where
  the new variable must be updated are only where the memory area is created,
  destroyed or resized.

Modified:
  head/bin/sh/memalloc.c
  head/bin/sh/memalloc.h

Modified: head/bin/sh/memalloc.c
==============================================================================
--- head/bin/sh/memalloc.c	Mon Dec 27 19:38:25 2010	(r216742)
+++ head/bin/sh/memalloc.c	Mon Dec 27 22:18:27 2010	(r216743)
@@ -127,7 +127,7 @@ static struct stack_block *stackp;
 static struct stackmark *markp;
 char *stacknxt;
 int stacknleft;
-int sstrnleft;
+char *sstrend;
 
 
 static void
@@ -146,6 +146,7 @@ stnewblock(int nbytes)
 	sp->prev = stackp;
 	stacknxt = SPACE(sp);
 	stacknleft = allocsize - (stacknxt - (char*)sp);
+	sstrend = stacknxt + stacknleft;
 	stackp = sp;
 	INTON;
 }
@@ -204,6 +205,7 @@ popstackmark(struct stackmark *mark)
 	}
 	stacknxt = mark->stacknxt;
 	stacknleft = mark->stacknleft;
+	sstrend = stacknxt + stacknleft;
 	INTON;
 }
 
@@ -250,6 +252,7 @@ growstackblock(int min)
 		stackp = sp;
 		stacknxt = SPACE(sp);
 		stacknleft = newlen - (stacknxt - (char*)sp);
+		sstrend = stacknxt + stacknleft;
 
 		/*
 		 * Stack marks pointing to the start of the old block
@@ -306,7 +309,6 @@ static char *
 growstrstackblock(int n, int min)
 {
 	growstackblock(min);
-	sstrnleft = stackblocksize() - n;
 	return stackblock() + n;
 }
 
@@ -325,31 +327,20 @@ growstackstr(void)
  */
 
 char *
-makestrspace(int min)
+makestrspace(int min, char *p)
 {
 	int len;
 
-	len = stackblocksize() - sstrnleft;
+	len = p - stackblock();
 	return (growstrstackblock(len, min));
 }
 
 
-
-void
-ungrabstackstr(char *s, char *p)
-{
-	stacknleft += stacknxt - s;
-	stacknxt = s;
-	sstrnleft = stacknleft - (p - s);
-}
-
-
 char *
 stputbin(const char *data, int len, char *p)
 {
 	CHECKSTRSPACE(len, p);
 	memcpy(p, data, len);
-	sstrnleft -= len;
 	return (p + len);
 }
 

Modified: head/bin/sh/memalloc.h
==============================================================================
--- head/bin/sh/memalloc.h	Mon Dec 27 19:38:25 2010	(r216742)
+++ head/bin/sh/memalloc.h	Mon Dec 27 22:18:27 2010	(r216743)
@@ -45,7 +45,7 @@ struct stackmark {
 
 extern char *stacknxt;
 extern int stacknleft;
-extern int sstrnleft;
+extern char *sstrend;
 
 pointer ckmalloc(size_t);
 pointer ckrealloc(pointer, int);
@@ -57,8 +57,7 @@ void setstackmark(struct stackmark *);
 void popstackmark(struct stackmark *);
 void grabstackblock(int);
 char *growstackstr(void);
-char *makestrspace(int);
-void ungrabstackstr(char *, char *);
+char *makestrspace(int, char *);
 char *stputbin(const char *data, int len, char *p);
 char *stputs(const char *data, char *p);
 
@@ -66,10 +65,10 @@ char *stputs(const char *data, char *p);
 
 #define stackblock() stacknxt
 #define stackblocksize() stacknleft
-#define STARTSTACKSTR(p)	p = stackblock(), sstrnleft = stackblocksize()
-#define STPUTC(c, p)	(--sstrnleft >= 0? (*p++ = (c)) : (p = growstackstr(), --sstrnleft, *p++ = (c)))
-#define CHECKSTRSPACE(n, p)	{ if (sstrnleft < n) p = makestrspace(n); }
-#define USTPUTC(c, p)	(--sstrnleft, *p++ = (c))
+#define STARTSTACKSTR(p)	p = stackblock()
+#define STPUTC(c, p)	do { if (p == sstrend) p = growstackstr(); *p++ = (c); } while(0)
+#define CHECKSTRSPACE(n, p)	{ if (sstrend - p < n) p = makestrspace(n, p); }
+#define USTPUTC(c, p)	(*p++ = (c))
 /*
  * STACKSTRNUL's use is where we want to be able to turn a stack
  * (non-sentinel, character counting string) into a C string,
@@ -77,10 +76,11 @@ char *stputs(const char *data, char *p);
  * Note: Because of STACKSTRNUL's semantics, STACKSTRNUL cannot be used
  * on a stack that will grabstackstr()ed.
  */
-#define STACKSTRNUL(p)	(sstrnleft == 0? (p = growstackstr(), *p = '\0') : (*p = '\0'))
-#define STUNPUTC(p)	(++sstrnleft, --p)
+#define STACKSTRNUL(p)	(p == sstrend ? (p = growstackstr(), *p = '\0') : (*p = '\0'))
+#define STUNPUTC(p)	(--p)
 #define STTOPC(p)	p[-1]
-#define STADJUST(amount, p)	(p += (amount), sstrnleft -= (amount))
-#define grabstackstr(p)	stalloc(stackblocksize() - sstrnleft)
+#define STADJUST(amount, p)	(p += (amount))
+#define grabstackstr(p)	stalloc((char *)p - stackblock())
+#define ungrabstackstr(s, p)	stunalloc((s))
 #define STPUTBIN(s, len, p)	p = stputbin((s), (len), p)
 #define STPUTS(s, p)	p = stputs((s), p)

Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201012272218.oBRMIRct038088>