shithub: scc

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Fix #if with not defined macros

When a not defined macro appears in a #if then it must be evaluated
to 0.

--- a/cc1/cpp.c

+++ b/cc1/cpp.c

@@ -195,6 +195,16 @@

 	char *arglist[NR_MACROARG], arguments[INPUTSIZ], buffer[BUFSIZE];

 	macroname = sym->name;

+	if (!(sym->flags & ISDECLARED)) {

+		/*

+		 * This case happens in #if were macro not defined must

+		 * be expanded to 0

+		 */

+		buffer[0] = '0';

+		buffer[1] = '\0';

+		elen = 1;

+		goto substitute;

+	}

 	if (sym == symfile) {

 		elen = sprintf(buffer, "\"%s\" ", input->fname);

 		goto substitute;

@@ -231,6 +241,9 @@

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

+	if (!(sym->flags & ISDECLARED))

+		delmacro(sym);

+

 	return 1;

 }

 #undef BUFSIZE

@@ -327,6 +340,7 @@

 		sym->flags |= ISDECLARED;

 	}

+	setnamespace(NS_IDEN);       /* Avoid polution in NS_CPP */

 	next();

 	if ((n = getpars(args)) == NR_MACROARG)

 		goto delete;

@@ -502,6 +516,7 @@

 cppif(void)

 {

 	setnamespace(NS_CPP);

+	disexpand = 0;

 	next();

 	ifclause(0, 0);

 }

@@ -548,6 +563,8 @@

 static void

 elif(void)

 {

+	setnamespace(NS_CPP);

+	disexpand = 0;

 	elseclause();

 	ifclause(0, 0);

 }

--- a/cc1/lex.c

+++ b/cc1/lex.c

@@ -18,7 +18,7 @@

 int cppoff;

 int lexmode = CCMODE;

-static unsigned lex_ns = NS_IDEN;

+static unsigned lex_ns = NS_IDEN, saved_ns;

 static int safe, eof;

 Input *input;

@@ -380,7 +380,7 @@

 	input->p = p;

 	tok2str();

 	sym = lookup(lex_ns);

-	if (sym->ns == NS_CPP && lexmode == CCMODE) {

+	if (sym->ns == NS_CPP) {

 		if (!disexpand && expand(begin, sym))

 			return next();

 		/*

@@ -493,6 +493,7 @@

 void

 setnamespace(int ns)

 {

+	saved_ns = (ns == NS_CPPCLAUSES) ? lex_ns : 0;

 	lex_ns = ns;

 }

@@ -518,6 +519,8 @@

 	skipspaces();

 	c = *input->begin;

 	if ((eof || lexmode == CPPMODE) && c == '\0') {

+		if (lexmode == CPPMODE)

+			lex_ns = saved_ns;

 		strcpy(yytext, "<EOF>");

 		if (cppctx && eof)

 			error("#endif expected");

@@ -538,7 +541,8 @@

 exit:

 	DBG(stderr, "TOKEN %s\n", yytext);

-	lex_ns = NS_IDEN;

+	if (lexmode == CCMODE)

+		lex_ns = NS_IDEN;

 	return yytoken;

 }