[hackers] [scc] Add support for ## preprocessor operator || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Sat, 3 Oct 2015 09:32:15 +0200 (CEST)

commit 9e00ad1d10ff45677223d724cc9bcd1fbc032f9e
Author: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
AuthorDate: Sat Oct 3 09:29:55 2015 +0200
Commit: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
CommitDate: Sat Oct 3 09:29:55 2015 +0200

    Add support for ## preprocessor operator
    
    It is known that current implementation can have some problems
    with macros which have _AT_ or $ characters in the definition, or
    in the parameters, but it is not a problem for a C program,
    because such characters only can apper between "" or ''.

diff --git a/cc1/cpp.c b/cc1/cpp.c
index d7939a8..311b1bb 100644
--- a/cc1/cpp.c
+++ b/cc1/cpp.c
_AT_@ -154,6 +154,13 @@ copymacro(char *buffer, char *s, size_t bufsiz, char *arglist[])
                 if (c != '_AT_') {
                         if (c == '#')
                                 continue;
+ if (c == '$') {
+ while (bp[-1] == ' ')
+ --bp, ++bufsiz;
+ while (s[1] == ' ')
+ ++s;
+ continue;
+ }
                         if (bufsiz-- == 0)
                                 goto expansion_too_long;
                         *bp++ = c;
_AT_@ -285,6 +292,11 @@ getdefs(Symbol *args[NR_MACROARG], int nargs, char *bp, size_t bufsiz)
         size_t len;
         int prevc = 0, ispar;
 
+ if (yytoken == '$') {
+ cpperror("'##' cannot appear at either end of a macro expansion");
+ return 0;
+ }
+
         for (;;) {
                 ispar = 0;
                 if (yytoken == IDEN && nargs >= 0) {
_AT_@ -308,10 +320,15 @@ getdefs(Symbol *args[NR_MACROARG], int nargs, char *bp, size_t bufsiz)
                         cpperror("too long macro");
                         return 0;
                 }
- memcpy(bp, yytext, len);
- bp += len;
- bufsiz -= len;
- if ((prevc = yytoken) != '#')
+ if (yytoken == '$') {
+ *bp++ = '$';
+ --bufsiz;
+ } else {
+ memcpy(bp, yytext, len);
+ bp += len;
+ bufsiz -= len;
+ }
+ if ((prevc = yytoken) != '#')
                         *bp++ = ' ';
                 next();
         }
diff --git a/cc1/lex.c b/cc1/lex.c
index 6bfbc03..2cd8c58 100644
--- a/cc1/lex.c
+++ b/cc1/lex.c
_AT_@ -525,6 +525,7 @@ operator(void)
         case '*': t = follow('=', MUL_EQ, '*'); break;
         case '/': t = follow('=', DIV_EQ, '/'); break;
         case '!': t = follow('=', NE, '!'); break;
+ case '#': t = follow('#', '$', '#'); break;
         case '-': t = minus(); break;
         case '+': t = plus(); break;
         case '.': t = dot(); break;
Received on Sat Oct 03 2015 - 09:32:15 CEST