shithub: scc

Info  •  Files  •  Log  •  Branches

Implement #if

This is a basic implementation of #if, where #elsif and defined() are not
implemented. Some work can be done to integrate cppif() and ifclause()

--- a/cc1/cpp.c

+++ b/cc1/cpp.c

@@ -476,6 +476,24 @@

 }

 static void

+cppif(void)

+{

+	Node *expr;

+	int status;

+	unsigned n;

+

+	if (cppctx == NR_COND-1)

+		error("too much nesting levels of conditional inclusion");

+	n = cppctx++;

+

+	if ((expr = iconstexpr()) == NULL)

+		error("parameter of #if is not an integer constant expression");

+	status = expr->sym->u.i != 0;

+	if (!(ifstatus[n] = status))

+		++cppoff;

+}

+

+static void

 ifdef(void)

 {

 	ifclause(1);

@@ -535,6 +553,7 @@

 		{INCLUDE, include},

 		{LINE, line},

 		{IFDEF, ifdef},

+		{IF, cppif},

 		{IFNDEF, ifndef},

 		{ELSE, elseclause},

 		{ENDIF, endif},

--- a/cc1/symbol.c

+++ b/cc1/symbol.c

@@ -262,6 +262,7 @@

 		{"include", INCLUDE, INCLUDE},

 		{"line", LINE, LINE},

 		{"ifdef", IFDEF, IFDEF},

+		{"if", IF, IF},

 		{"else", ELSE, ELSE},

 		{"ifndef", IFNDEF, IFNDEF},

 		{"endif", ENDIF, ENDIF},