shithub: scc

Info  •  Files  •  Log  •  Branches

Simplify fill() and convert it to moreinput()

--- a/cc1/cpp.c

+++ b/cc1/cpp.c

@@ -281,7 +281,7 @@

 	for (++p; isspace(*p); ++p)

 		/* nothing */;

 	if (*p == '\0')

-		return NULL;

+		return p;

 	for (q = p; isalpha(*q); ++q)

 		/* nothing */;

 	if ((n = q - p) == 0)

@@ -296,7 +296,7 @@

 			/* nothing */;

 		if (*q != '\0')

 			error("trailing characters after preprocessor directive");

-		return NULL;

+		return q;

 	}

 incorrect:

 	error("incorrect preprocessor directive");

--- a/cc1/lex.c

+++ b/cc1/lex.c

@@ -59,7 +59,8 @@

 	ip = xmalloc(sizeof(Input));

 	ip->fname = fname;

 	ip->next = input;

-	ip->line = NULL;

+	ip->begin = ip->p = ip->line = xmalloc(INPUTSIZ);

+	*ip->begin = '\0';

 	ip->nline = nline;

 	ip->fp = fp;

 	input = ip;

@@ -116,7 +117,7 @@

 {

 	int c;

 	FILE *fp;

-	

+

 repeat:

 	while (feof(input->fp) && !eof)

 		delinput();

@@ -129,9 +130,11 @@

 			goto repeat;

 		ungetc(c, fp);

 		c = '\\';

-	}

-	if (c == '\n' && ++input->nline == 0)

+	} else if (c == EOF) {

+		goto repeat;

+	} else if (c == '\n' && ++input->nline == 0) {

 		die("input file '%s' too long", getfname());

+	}

 	return c;

 }

@@ -185,25 +188,17 @@

 }

 static bool

-fill(void)

+moreinput(void)

 {

 	char *p;

-	int c;

 repeat:

-	if (eof)

-		return 0;

-	if (input->begin && *input->begin != '\0')

-		return 1;

-	if (!input->line)

-		input->line = xmalloc(INPUTSIZ);

+	*(p = input->line) = '\0';

 	readline();

-	if (*input->line == '\0')

+	if ((p = preprocessor(p)) == '\0')

 		goto repeat;

-	if ((p = preprocessor(input->line)) == NULL)

-		goto repeat;

 	input->p = input->begin = p;

-	return 1;

+	return *p != '\0';

 }

 static void

@@ -369,21 +364,10 @@

 	if (c == '\0')

 		error("missing terminating '\"' character");

-	++input->p;

+	input->begin = input->p + 1;

-	for (;;) {

-		input->begin = input->p;

-		if (isspace((c = *input->p))) {

-			++input->p;

-		} else if (c == '\0' && fill()) {

-			continue;

-		} else if (c == '"') {

-			goto repeat;

-		} else {

-			break;

-		}

-	}

-

+	if (ahead() == '"')

+		goto repeat;

 	*bp = '\0';

 	sym = newsym(NS_IDEN);

 	sym->u.s = xstrdup(buf);

@@ -506,32 +490,44 @@

 	lex_ns = ns;

 }

+static void

+skipspaces(void)

+{

+	char *p;

+

+repeat:

+	for (p = input->begin; isspace(*p); ++p)

+		/* nothing */;

+	if (*p == '\0') {

+		if (!moreinput())

+			return;

+		goto repeat;

+	}

+	input->begin = input->p = p;

+}

+

 unsigned

 next(void)

 {

 	char c;

-repeat:

-	if (!fill()) {

+	skipspaces();

+	if (eof) {

 		strcpy(yytext, "<EOF>");

 		return yytoken = EOFTOK;

 	}

-	while (isspace(*input->begin))

-		++input->begin;

-	if ((c = *(input->p = input->begin)) == '\0')

-		goto repeat;

-	if (isalpha(c) || c == '_') {

+	c = *input->begin;

+	if (isalpha(c) || c == '_')

 		yytoken = iden();

-	} else if (isdigit(c)) {

+	else if (isdigit(c))

 		yytoken = number();

-	} else if (c == '"') {

+	else if (c == '"')

 		yytoken = string();

-	} else if (c == '\'') {

+	else if (c == '\'')

 		yytoken = character();

-	} else {

+	else

 		yytoken = operator();

-	}

 	lex_ns = NS_IDEN;

 	return yytoken;

 }

@@ -552,16 +548,8 @@

 char

 ahead(void)

 {

-	int c;

-

-repeat:

-	if (!fill())

-		return EOFTOK;

-	while (isspace(c = *input->begin))

-		++input->begin;

-	if (c == '\0')

-		goto repeat;

-	return c;

+	skipspaces();

+	return *input->begin;

 }

 void

@@ -596,7 +584,7 @@

 				goto jump;

 			break;

 		}

-		if (!fill())

+		if (!moreinput())

 			exit(-1);

 	}

 jump: