[hackers] [scc] Join #if and #ifdef || Roberto E. Vargas Caballero

[git]

commit 167690b43dd4a0f6279bd9e8dd6f4aa84a3ca375
Author:     Roberto E. Vargas Caballero <k...@shike2.com>
AuthorDate: Mon Jul 27 10:50:09 2015 +0200
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Mon Jul 27 10:50:09 2015 +0200

    Join #if and #ifdef

diff --git a/cc1/cpp.c b/cc1/cpp.c
index 093e474..9099840 100644
--- a/cc1/cpp.c
+++ b/cc1/cpp.c
@@ -451,58 +451,53 @@ usererr(void)
 }
 
 static void
-ifclause(int isdef)
+ifclause(int negate, int isifdef)
 {
        Symbol *sym;
        unsigned n;
        int status;
+       Node *expr;
 
        if (cppctx == NR_COND-1)
                error("too much nesting levels of conditional inclusion");
-
        n = cppctx++;
-       if (yytoken != IDEN) {
-               error("no macro name given in #%s directive",
-                     (isdef) ? "ifdef" : "ifndef");
-       }
 
-       sym = lookup(NS_CPP);
-       next();
-
-       status = (sym->flags & ISDEFINED) != 0 == isdef;
+       if (isifdef) {
+               if (yytoken != IDEN) {
+                       error("no macro name given in #%s directive",
+                             (negate) ? "ifndef" : "ifdef");
+               }
+               sym = lookup(NS_CPP);
+               next();
+               status = (sym->flags & ISDEFINED) != 0;
+       } else {
+               if ((expr = iconstexpr()) == NULL)
+                       error("parameter of #if is not an integer constant 
expression");
+               status = expr->sym->u.i != 0;
+       }
 
-       if (!(ifstatus[n] = status))
+       if (negate)
+               status = !status;
+       if ((ifstatus[n] = status) == 0)
                ++cppoff;
 }
 
 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;
+       ifclause(0, 0);
 }
 
 static void
 ifdef(void)
 {
-       ifclause(1);
+       ifclause(0, 1);
 }
 
 static void
 ifndef(void)
 {
-       ifclause(0);
+       ifclause(1, 1);
 }
 
 static void