scc

commit 69a0a3e07aee3304446942c49527d65ebc5f7c85
parent b390c994ee75e9c45616cfc91bf89d869d228310
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Fri, 22 Sep 2017 14:24:03 +0100

[as] Rewrite getargs()

Getargs() has not to do parsing anymore since this task is
done in expr() now.

Diffstat:
M
as/as.h
 | 
2
+-
M
as/expr.c
 | 
63
++++++++++++++++++++++++++++++++++++++++++++-------------------
M
as/parser.c
 | 
24
++++--------------------

3 files changed, 49 insertions(+), 40 deletions(-)
diff --git a/as/as.h b/as/as.h
@@ -112,7 +112,7 @@ extern int nextline(FILE *fp, struct line *linep);
 #endif
 
 /* expr.c */
-extern Node *expr(char *s);
+extern Node *expr(char **s);
 extern void deltree(Node *np);
 
 /*
diff --git a/as/expr.c b/as/expr.c
@@ -175,8 +175,8 @@ iden(void)
 	int c;
 	char *p;
 
-	for (endp = textp+1; isalnum(c = *endp) || c == '_' || c == '.'; ++endp)
-		/* nothing */;
+	while (isalnum(c = *endp) || c == '_' || c == '.')
+		++endp;
 	tok2str();
 	yylval.sym = lookup(yytext);
 
@@ -189,8 +189,8 @@ number(void)
 	int c;
 	char *p;
 
-	for (endp = textp+1; isxdigit(*endp); ++endp)
-		/* nothing */;
+	while (isxdigit(*endp))
+		++endp;
 	tok2str();
 	yylval.sym = tmpsym(atoi(yytext));  /* TODO: parse the string */
 
@@ -203,8 +203,8 @@ character(void)
 	int c;
 	char *p;
 
-	for (endp = textp+1; *endp != '\''; ++endp)
-		/* nothing */;
+	while (*endp != '\'')
+		++endp;
 	return NUMBER;
 }
 
@@ -214,31 +214,51 @@ string(void)
 	int c;
 	char *p;
 
-	for (endp = textp+1; *endp != '"'; ++endp)
-		/* nothing */;
+	while (*endp != '"')
+		++endp;
 	return STRING;
 }
 
 static int
+operator(void)
+{
+	int c;
+
+	++endp;
+	if ((c = *textp) == '>')
+		c = follow('=', '>', LE, SHL, '>');
+	else if (c == '<')
+		c = follow('=', '<', GE, SHR, '>');
+	tok2str();
+
+	return c;
+}
+
+static int
 next(void)
 {
 	int c;
 
 	while (isspace(*textp))
 		++textp;
-	c = *textp;
+
+	endp = textp;
+	if ((c = *textp) == '\0') {
+		strcpy(yytext, "EOF");
+		yylen = 3;
+		return EOF;
+	}
+
 	if (isalpha(c) || c == '_' || c == '.')
 		c = iden();
 	else if (isdigit(c))
 		c = number();
-	else if (c == '>')
-		c = follow('=', '>', LE, SHL, '>');
-	else if (c == '<')
-		c = follow('=', '<', GE, SHR, '>');
-	else if (c == '\'')
-		c = character();
 	else if (c == '\"')
 		c = string();
+	else if (c == '\'')
+		c = character();
+	else
+		c = operator();
 
 	return yytoken = c;
 }
@@ -398,15 +418,20 @@ or(void)
 }
 
 Node *
-expr(char *s)
+expr(char **s)
 {
 	Node *np;
 
-	textp = s;
+	if (*s == '\0')
+		return NULL;
+
+	textp = *s;
 	next();
 	np = or();
 
-	if (*textp != '\0')
-		error("trailing characters in expression '%s'", textp);
+	if (yytoken != ',' && yytoken != EOF)
+		error("trailing characters in expression '%s:%s'", *s, textp);
+	*s = endp;
+
 	return np;
 }
diff --git a/as/parser.c b/as/parser.c
@@ -35,33 +35,17 @@ error(char *msg, ...)
 Node **
 getargs(char *s)
 {
-	char *t;
-	int ch, len;
 	Node **ap;
 	static Node *args[NARGS];
 
 	if (!s)
 		return NULL;
 
-	for (ap = args; ; *ap++ = expr(t)) {
-		while (isspace(*s))
-			++s;
-		if (*s == '\0')
-			break;
-		if (ap == &args[NARGS-1])
-			error("too many arguments in one instruction");
-
-		for (t = s; *s && *s != ','; s++)
-			/* nothing */;
-		len = t - s;
-		if (*s != '\0')
-			*s++ = '\0';
-		if (len == 0)
-			error("wrong operand '%s'", t);
+	for (ap = args; ap < &args[NARGS-1]; ++ap) {
+		if ((*ap = expr(&s)) == NULL)
+			return args;
 	}
-	*ap = NULL;
-
-	return args;
+	error("too many arguments in one instruction");
 }
 
 static char *