[hackers] [scc] Rewrite clever expressions in cpp.c || Roberto E. Vargas Caballero

[git]

commit 8022f78f34e2b0532f880d2d64d363bb1e20531d
Author:     Roberto E. Vargas Caballero <k...@shike2.com>
AuthorDate: Sat Jul 18 10:31:19 2015 +0200
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Sat Jul 18 10:31:19 2015 +0200

    Rewrite clever expressions in cpp.c
    
    These expressions were too much clever and obscure. Using
    an intermediate variable helps to understand them.

diff --git a/cc1/cpp.c b/cc1/cpp.c
index 65808f2..b3015b5 100644
--- a/cc1/cpp.c
+++ b/cc1/cpp.c
@@ -447,9 +447,11 @@ ifclause(int isdef)
 {
        Symbol *sym;
        unsigned n;
+       int status;
 
        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",
@@ -458,7 +460,10 @@ ifclause(int isdef)
 
        sym = lookup(NS_CPP);
        next();
-       if (!(ifstatus[n] = (sym->flags & ISDEFINED) != 0 == isdef))
+
+       status = (sym->flags & ISDEFINED) != 0 == isdef;
+
+       if (!(ifstatus[n] = status))
                ++cppoff;
 }
 
@@ -486,10 +491,13 @@ endif(void)
 static void
 elseclause(void)
 {
+       int status;
+
        if (cppctx == 0)
                error("#else without #ifdef/ifndef");
 
-       cppoff += (ifstatus[cppctx-1] ^= 1) ? -1 : 1;
+       status = (ifstatus[cppctx-1] ^= 1);
+       cppoff += (status) ? -1 : 1;
 }
 
 static void