sh: Code size optimizations to "stack string" memory allocation:

* Prefer one CHECKSTRSPACE with multiple USTPUTC to multiple STPUTC.
* Add STPUTS macro (based on function) and use it instead of loops that add
  nul-terminated strings to the stack string.

No functional change is intended, but code size is about 1K less on i386.

8 files changed, 47 insertions, 33 deletions

diff --git a/bin/sh/cd.c b/bin/sh/cd.c
index 2ac4b10..068dfb7 100644
--- a/bin/sh/cd.c
+++ b/bin/sh/cd.c
@@ -192,8 +192,7 @@ cdlogical(char *dest)
 			STPUTC('/', p);
 		first = 0;
 		component = q;
-		while (*q)
-			STPUTC(*q++, p);
+		STPUTS(q, p);
 		if (equal(component, ".."))
 			continue;
 		STACKSTRNUL(p);
@@ -273,10 +272,8 @@ findcwd(char *dir)
 	scopy(dir, cdcomppath);
 	STARTSTACKSTR(new);
 	if (*dir != '/') {
-		p = curdir;
-		while (*p)
-			STPUTC(*p++, new);
-		if (p[-1] == '/')
+		STPUTS(curdir, new);
+		if (STTOPC(new) == '/')
 			STUNPUTC(new);
 	}
 	while ((p = getcomponent()) != NULL) {
@@ -284,8 +281,7 @@ findcwd(char *dir)
 			while (new > stackblock() && (STUNPUTC(new), *new) != '/');
 		} else if (*p != '\0' && ! equal(p, ".")) {
 			STPUTC('/', new);
-			while (*p)
-				STPUTC(*p++, new);
+			STPUTS(p, new);
 		}
 	}
 	if (new == stackblock())
diff --git a/bin/sh/eval.c b/bin/sh/eval.c
index c306e73..5bae2f2 100644
--- a/bin/sh/eval.c
+++ b/bin/sh/eval.c
@@ -135,8 +135,7 @@ evalcmd(int argc, char **argv)
                         STARTSTACKSTR(concat);
                         ap = argv + 2;
                         for (;;) {
-                                while (*p)
-                                        STPUTC(*p++, concat);
+                                STPUTS(p, concat);
                                 if ((p = *ap++) == NULL)
                                         break;
                                 STPUTC(' ', concat);
diff --git a/bin/sh/expand.c b/bin/sh/expand.c
index d251ed0..7a3b9d9 100644
--- a/bin/sh/expand.c
+++ b/bin/sh/expand.c
@@ -225,6 +225,7 @@ argstr(char *p, int flag)
 	if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 		p = exptilde(p, flag);
 	for (;;) {
+		CHECKSTRSPACE(2, expdest);
 		switch (c = *p++) {
 		case '\0':
 		case CTLENDVAR:
@@ -235,16 +236,16 @@ argstr(char *p, int flag)
 			if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 				break;
 			if ((flag & EXP_FULL) != 0)
-				STPUTC(c, expdest);
+				USTPUTC(c, expdest);
 			break;
 		case CTLQUOTEEND:
 			lit_quoted = 0;
 			break;
 		case CTLESC:
 			if (quotes)
-				STPUTC(c, expdest);
+				USTPUTC(c, expdest);
 			c = *p++;
-			STPUTC(c, expdest);
+			USTPUTC(c, expdest);
 			if (split_lit && !lit_quoted)
 				recordregion(expdest - stackblock() -
 				    (quotes ? 2 : 1),
@@ -267,7 +268,7 @@ argstr(char *p, int flag)
 			 * sort of a hack - expand tildes in variable
 			 * assignments (after the first '=' and after ':'s).
 			 */
-			STPUTC(c, expdest);
+			USTPUTC(c, expdest);
 			if (split_lit && !lit_quoted)
 				recordregion(expdest - stackblock() - 1,
 				    expdest - stackblock(), 0);
@@ -279,7 +280,7 @@ argstr(char *p, int flag)
 			}
 			break;
 		default:
-			STPUTC(c, expdest);
+			USTPUTC(c, expdest);
 			if (split_lit && !lit_quoted)
 				recordregion(expdest - stackblock() - 1,
 				    expdest - stackblock(), 0);
@@ -902,8 +903,7 @@ varvalue(char *name, int quoted, int subtype, int flag)
 			STPUTC(*p++, expdest); \
 		} \
 	} else \
-		while (*p) \
-			STPUTC(*p++, expdest); \
+		STPUTS(p, expdest); \
 	} while (0)
 
 
@@ -1573,8 +1573,7 @@ cvtnum(int num, char *buf)
 	if (neg)
 		*--p = '-';
 
-	while (*p)
-		STPUTC(*p++, buf);
+	STPUTS(p, buf);
 	return buf;
 }
 
diff --git a/bin/sh/histedit.c b/bin/sh/histedit.c
index 3fc1782..26d46a8 100644
--- a/bin/sh/histedit.c
+++ b/bin/sh/histedit.c
@@ -411,8 +411,7 @@ fc_replace(const char *s, char *p, char *r)
 	STARTSTACKSTR(dest);
 	while (*s) {
 		if (*s == *p && strncmp(s, p, plen) == 0) {
-			while (*r)
-				STPUTC(*r++, dest);
+			STPUTS(r, dest);
 			s += plen;
 			*p = '\0';	/* so no more matches */
 		} else
diff --git a/bin/sh/memalloc.c b/bin/sh/memalloc.c
index 9158719..d00b4d9 100644
--- a/bin/sh/memalloc.c
+++ b/bin/sh/memalloc.c
@@ -340,3 +340,20 @@ ungrabstackstr(char *s, char *p)
 	stacknxt = s;
 	sstrnleft = stacknleft - (p - s);
 }
+
+
+char *
+stputbin(const char *data, int len, char *p)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		STPUTC(data[i], p);
+	return (p);
+}
+
+char *
+stputs(const char *data, char *p)
+{
+	return (stputbin(data, strlen(data), p));
+}
diff --git a/bin/sh/memalloc.h b/bin/sh/memalloc.h
index 563927a..88848dd 100644
--- a/bin/sh/memalloc.h
+++ b/bin/sh/memalloc.h
@@ -61,6 +61,8 @@ void grabstackblock(int);
 char *growstackstr(void);
 char *makestrspace(void);
 void ungrabstackstr(char *, char *);
+char *stputbin(const char *data, int len, char *p);
+char *stputs(const char *data, char *p);
 
 
 
@@ -82,3 +84,5 @@ void ungrabstackstr(char *, char *);
 #define STTOPC(p)	p[-1]
 #define STADJUST(amount, p)	(p += (amount), sstrnleft -= (amount))
 #define grabstackstr(p)	stalloc(stackblocksize() - sstrnleft)
+#define STPUTBIN(s, len, p)	p = stputbin((s), (len), p)
+#define STPUTS(s, p)	p = stputs((s), p)
diff --git a/bin/sh/miscbltin.c b/bin/sh/miscbltin.c
index d9ac8a3..dc200b6 100644
--- a/bin/sh/miscbltin.c
+++ b/bin/sh/miscbltin.c
@@ -172,11 +172,12 @@ readcmd(int argc __unused, char **argv __unused)
 		}
 		if (c == '\0')
 			continue;
+		CHECKSTRSPACE(1, p);
 		if (backslash) {
 			backslash = 0;
 			startword = 0;
 			if (c != '\n')
-				STPUTC(c, p);
+				USTPUTC(c, p);
 			continue;
 		}
 		if (!rflag && c == '\\') {
@@ -194,14 +195,14 @@ readcmd(int argc __unused, char **argv __unused)
 			if (is_ifs == 1) {
 				/* Ignore leading IFS whitespace */
 				if (saveall)
-					STPUTC(c, p);
+					USTPUTC(c, p);
 				continue;
 			}
 			if (is_ifs == 2 && startword == 1) {
 				/* Only one non-whitespace IFS per word */
 				startword = 2;
 				if (saveall)
-					STPUTC(c, p);
+					USTPUTC(c, p);
 				continue;
 			}
 		}
@@ -212,7 +213,7 @@ readcmd(int argc __unused, char **argv __unused)
 			if (saveall)
 				/* Not just a spare terminator */
 				saveall++;
-			STPUTC(c, p);
+			USTPUTC(c, p);
 			continue;
 		}
 
@@ -222,7 +223,7 @@ readcmd(int argc __unused, char **argv __unused)
 		if (ap[1] == NULL) {
 			/* Last variable needs all IFS chars */
 			saveall++;
-			STPUTC(c, p);
+			USTPUTC(c, p);
 			continue;
 		}
 
diff --git a/bin/sh/parser.c b/bin/sh/parser.c
index 01907e8..2687003 100644
--- a/bin/sh/parser.c
+++ b/bin/sh/parser.c
@@ -1017,6 +1017,7 @@ parsebackq(char *out, struct nodelist **pbqlist,
 				setprompt(2);
 				needprompt = 0;
 			}
+			CHECKSTRSPACE(2, oout);
 			switch (c = pgetc()) {
 			case '`':
 				goto done;
@@ -1031,14 +1032,14 @@ parsebackq(char *out, struct nodelist **pbqlist,
 					/*
 					 * If eating a newline, avoid putting
 					 * the newline into the new character
-					 * stream (via the STPUTC after the
+					 * stream (via the USTPUTC after the
 					 * switch).
 					 */
 					continue;
 				}
                                 if (c != '\\' && c != '`' && c != '$'
                                     && (!dblquote || c != '"'))
-                                        STPUTC('\\', oout);
+                                        USTPUTC('\\', oout);
 				break;
 
 			case '\n':
@@ -1054,10 +1055,10 @@ parsebackq(char *out, struct nodelist **pbqlist,
 			default:
 				break;
 			}
-			STPUTC(c, oout);
+			USTPUTC(c, oout);
                 }
 done:
-                STPUTC('\0', oout);
+                USTPUTC('\0', oout);
                 olen = oout - stackblock();
 		INTOFF;
 		ostr = ckmalloc(olen);
@@ -1444,7 +1445,6 @@ parsesub: {
 	char *p;
 	static const char types[] = "}-+?=";
 	int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
-	int i;
 	int linno;
 	int length;
 
@@ -1498,8 +1498,7 @@ parsesub: {
 					linno -= funclinno - 1;
 				snprintf(buf, sizeof(buf), "%d", linno);
 				STADJUST(-6, out);
-				for (i = 0; buf[i] != '\0'; i++)
-					STPUTC(buf[i], out);
+				STPUTS(buf, out);
 				flags |= VSLINENO;
 			}
 		} else if (is_digit(c)) {