[hackers] [scc] Add support for define() in #if || Roberto E. Vargas Caballero

[git]

commit 18bc293eda5e66a9cd3f86d9dcb1c987de599779
Author:     Roberto E. Vargas Caballero <k...@shike2.com>
AuthorDate: Mon Oct 5 15:39:32 2015 +0200
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Mon Oct 5 15:39:32 2015 +0200

    Add support for define() in #if
    
    This is really stupidity of ansi c comitee, but ok, we need it.

diff --git a/cc1/cpp.c b/cc1/cpp.c
index a5ad74a..4ed4ffb 100644
--- a/cc1/cpp.c
+++ b/cc1/cpp.c
@@ -228,7 +228,9 @@ expand(char *begin, Symbol *sym)
        char *arglist[NR_MACROARG], arguments[INPUTSIZ], buffer[BUFSIZE];
 
        macroname = sym->name;
-       if (!(sym->flags & ISDECLARED)) {
+       if ((sym->flags & ISDECLARED) == 0) {
+               if (namespace == NS_CPP && !strcmp(sym->name, "defined"))
+                       return 0;  /* we found a 'defined in an #if */
                /*
                 * This case happens in #if were macro not defined must
                 * be expanded to 0
diff --git a/cc1/expr.c b/cc1/expr.c
index bc555e4..6ec964b 100644
--- a/cc1/expr.c
+++ b/cc1/expr.c
@@ -496,6 +496,32 @@ negation(char op, Node *np)
        }
 }
 
+static Symbol *
+notdefined(Symbol *sym)
+{
+       int isdef;
+
+       if (namespace == NS_CPP && !strcmp(sym->name, "defined")) {
+               disexpand = 1;
+               next();
+               expect('(');
+               sym = yylval.sym;
+               expect(IDEN);
+               expect(')');
+
+               isdef = (sym->flags & ISDEFINED) != 0;
+               sym = newsym(NS_IDEN);
+               sym->type = inttype;
+               sym->flags |= ISCONSTANT;
+               sym->u.i = isdef;
+               disexpand = 0;
+               return sym;
+       }
+       errorp("'%s' undeclared", yytext);
+       sym->type = inttype;
+       return install(sym->ns, yylval.sym);
+}
+
 /*************************************************************
  * grammar functions                                         *
  *************************************************************/
@@ -505,18 +531,18 @@ primary(void)
        Node *np;
        Symbol *sym;
 
+       sym = yylval.sym;
        switch (yytoken) {
        case CONSTANT:
-               np = constnode(yylval.sym);
+       constant:
+               np = constnode(sym);
                next();
                break;
        case IDEN:
-               sym = yylval.sym;
-               if ((sym->flags & ISDECLARED) == 0) {
-                       errorp("'%s' undeclared", yytext);
-                       sym->type = inttype;
-                       install(sym->ns, yylval.sym);
-               }
+               if ((sym->flags & ISDECLARED) == 0)
+                       sym = notdefined(sym);
+               if (sym->flags & ISCONSTANT)
+                       goto constant;
                sym->flags |= ISUSED;
                np = varnode(sym);
                next();