[hackers] [scc] Implement #if || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Mon, 27 Jul 2015 09:47:14 +0200 (CEST)

commit 3ae3ab16c27973a7fdee2bd6daad1aad9cc9910c
Author: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
AuthorDate: Mon Jul 27 09:44:34 2015 +0200
Commit: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
CommitDate: Mon Jul 27 09:44:34 2015 +0200

    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()

diff --git a/cc1/cpp.c b/cc1/cpp.c
index 8e9f3e5..093e474 100644
--- a/cc1/cpp.c
+++ b/cc1/cpp.c
_AT_@ -476,6 +476,24 @@ ifclause(int isdef)
 }
 
 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);
_AT_@ -535,6 +553,7 @@ cpp(void)
                 {INCLUDE, include},
                 {LINE, line},
                 {IFDEF, ifdef},
+ {IF, cppif},
                 {IFNDEF, ifndef},
                 {ELSE, elseclause},
                 {ENDIF, endif},
diff --git a/cc1/symbol.c b/cc1/symbol.c
index c581dd1..8c86de2 100644
--- a/cc1/symbol.c
+++ b/cc1/symbol.c
_AT_@ -262,6 +262,7 @@ ikeywords(void)
                 {"include", INCLUDE, INCLUDE},
                 {"line", LINE, LINE},
                 {"ifdef", IFDEF, IFDEF},
+ {"if", IF, IF},
                 {"else", ELSE, ELSE},
                 {"ifndef", IFNDEF, IFNDEF},
                 {"endif", ENDIF, ENDIF},
Received on Mon Jul 27 2015 - 09:47:14 CEST