expand: Merge syntax/quotes in memtodest with flags

Commit Message

Herbert Xu May 27, 2018, 4:17 p.m. UTC

The function arguments syntax and quotes are both derived from
the expansion flags.  As syntax is only used by memtodest we do
not need to maintain it outside of the function at all.

The only place that uses something other than BASESYNTAX or DQSYNTAX
is exptilde.  However in that case DQSYNTAX has exactly the same
effect as SQSYNTAX.

This patch merges these two arguments into a single flags.  The
macro QUOTES_KEEPNUL has been renamed to EXP_KEEPNUL in order
to keep the namespace separate.

Signed-off-by: Herbert Xu <[e-mail]>

Patch

diff --git a/src/expand.c b/src/expand.c
index eb50e15..c565646 100644
--- a/src/expand.c
+++ b/src/expand.c
@@ -86,8 +86,6 @@ 
 
 /* Add CTLESC when necessary. */
 #define QUOTES_ESC	(EXP_FULL | EXP_CASE)
-/* Do not skip NUL characters. */
-#define QUOTES_KEEPNUL	EXP_TILDE
 
 /*
  * Structure specifying which parts of the string should be searched
@@ -117,8 +115,8 @@  STATIC char *exptilde(char *, char *, int);
 STATIC void expbackq(union node *, int);
 STATIC const char *subevalvar(char *, char *, int, int, int, int, int);
 STATIC char *evalvar(char *, int);
-STATIC size_t strtodest(const char *, const char *, int);
-STATIC void memtodest(const char *, size_t, const char *, int);
+static size_t strtodest(const char *p, int flags);
+static void memtodest(const char *p, size_t len, int flags);
 STATIC ssize_t varvalue(char *, int, int, int);
 STATIC void expandmeta(struct strlist *, int);
 #ifdef HAVE_GLOB
@@ -359,7 +357,6 @@  exptilde(char *startp, char *p, int flag)
 	signed char c;
 	char *name;
 	const char *home;
-	int quotes = flag & QUOTES_ESC;
 
 	name = p + 1;
 
@@ -388,7 +385,7 @@  done:
 	if (!home)
 		goto lose;
 	*p = c;
-	strtodest(home, SQSYNTAX, quotes);
+	strtodest(home, flag | EXP_QUOTED);
 	return (p);
 lose:
 	*p = c;
@@ -513,7 +510,6 @@  expbackq(union node *cmd, int flag)
 	char *p;
 	char *dest;
 	int startloc;
-	char const *syntax = flag & EXP_QUOTED ? DQSYNTAX : BASESYNTAX;
 	struct stackmark smark;
 
 	INTOFF;
@@ -527,7 +523,7 @@  expbackq(union node *cmd, int flag)
 	if (i == 0)
 		goto read;
 	for (;;) {
-		memtodest(p, i, syntax, flag & QUOTES_ESC);
+		memtodest(p, i, flag);
 read:
 		if (in.fd < 0)
 			break;
@@ -835,8 +831,9 @@  end:
  * Put a string on the stack.
  */
 
-STATIC void
-memtodest(const char *p, size_t len, const char *syntax, int quotes) {
+static void memtodest(const char *p, size_t len, int flags)
+{
+	const char *syntax = flags & EXP_QUOTED ? DQSYNTAX : BASESYNTAX;
 	char *q;
 
 	if (unlikely(!len))
@@ -847,11 +844,11 @@  memtodest(const char *p, size_t len, const char *syntax, int quotes) {
 	do {
 		int c = (signed char)*p++;
 		if (c) {
-			if ((quotes & QUOTES_ESC) &&
+			if ((flags & QUOTES_ESC) &&
 			    ((syntax[c] == CCTL) ||
-			     (syntax != BASESYNTAX && syntax[c] == CBACK)))
+			     (flags & EXP_QUOTED && syntax[c] == CBACK)))
 				USTPUTC(CTLESC, q);
-		} else if (!(quotes & QUOTES_KEEPNUL))
+		} else if (!(flags & EXP_KEEPNUL))
 			continue;
 		USTPUTC(c, q);
 	} while (--len);
@@ -860,14 +857,10 @@  memtodest(const char *p, size_t len, const char *syntax, int quotes) {
 }
 
 
-STATIC size_t
-strtodest(p, syntax, quotes)
-	const char *p;
-	const char *syntax;
-	int quotes;
+static size_t strtodest(const char *p, int flags)
 {
 	size_t len = strlen(p);
-	memtodest(p, len, syntax, quotes);
+	memtodest(p, len, flags);
 	return len;
 }
 
@@ -886,15 +879,14 @@  varvalue(char *name, int varflags, int flags, int quoted)
 	int sep;
 	char sepc;
 	char **ap;
-	char const *syntax;
 	int subtype = varflags & VSTYPE;
 	int discard = subtype == VSPLUS || subtype == VSLENGTH;
-	int quotes = (discard ? 0 : (flags & QUOTES_ESC)) | QUOTES_KEEPNUL;
 	ssize_t len = 0;
 	char c;
 
+	flags |= EXP_KEEPNUL;
+	flags &= discard ? ~QUOTES_ESC : ~0;
 	sep = (flags & EXP_FULL) << CHAR_BIT;
-	syntax = quoted ? DQSYNTAX : BASESYNTAX;
 
 	switch (*name) {
 	case '$':
@@ -950,11 +942,11 @@  param:
 		if (!(ap = shellparam.p))
 			return -1;
 		while ((p = *ap++)) {
-			len += strtodest(p, syntax, quotes);
+			len += strtodest(p, flags);
 
 			if (*ap && sep) {
 				len++;
-				memtodest(&sepc, 1, syntax, quotes);
+				memtodest(&sepc, 1, flags);
 			}
 		}
 		break;
@@ -979,7 +971,7 @@  value:
 		if (!p)
 			return -1;
 
-		len = strtodest(p, syntax, quotes);
+		len = strtodest(p, flags);
 		break;
 	}
 
diff --git a/src/expand.h b/src/expand.h
index 90f5328..617b851 100644
--- a/src/expand.h
+++ b/src/expand.h
@@ -58,6 +58,7 @@  struct arglist {
 #define EXP_VARTILDE2	0x40	/* expand tildes after colons only */
 #define EXP_WORD	0x80	/* expand word in parameter expansion */
 #define EXP_QUOTED	0x100	/* expand word in double quotes */
+#define EXP_KEEPNUL	0x200	/* do not skip NUL characters */
 
 
 union node;