[hackers] [scc] [cc1] Add warnings in builtin_va_start() || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Mon, 13 Feb 2017 17:00:19 +0100 (CET)

commit ad2e30089260ee4dc4bb7bd674ab65516ffee854
Author: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
AuthorDate: Mon Feb 13 16:58:29 2017 +0100
Commit: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
CommitDate: Mon Feb 13 16:58:29 2017 +0100

    [cc1] Add warnings in builtin_va_start()
    
    There are a lot of strange conditions in va_start()
    that should be informed as warnings to the user,
    because any of them can generate wrong code in
    some implementations/architectures.

diff --git a/cc1/builtin.c b/cc1/builtin.c
index 275bdaf..7768df1 100644
--- a/cc1/builtin.c
+++ b/cc1/builtin.c
_AT_@ -18,7 +18,7 @@ builtin_va_arg(Symbol *sym)
 
         if (!valid_va_list(ap->type)) {
                 errorp("incorrect parameters for va_arg");
- return constnode(zero);
+ goto error;
         }
         if (tp == booltype ||
             tp == chartype || tp == uchartype || tp == schartype ||
_AT_@ -30,6 +30,9 @@ builtin_va_arg(Symbol *sym)
         np = node(OBUILTIN, tp, ap, NULL);
         np->sym = sym;
         return np;
+
+error:
+ return constnode(zero);
 }
 
 static Node *
_AT_@ -55,16 +58,31 @@ static Node *
 builtin_va_start(Symbol *sym)
 {
         Node *np, *ap, *last;
+ Symbol **p, *lastsym;
+ Type *tp;
 
         ap = assign();
         expect(',');
         if (yytoken != IDEN)
                 goto error;
- last = varnode(yylval.sym);
+ lastsym = yylval.sym;
+ last = varnode(lastsym);
         next();
 
- if (!valid_va_list(ap->type))
- goto error;
+ if (!valid_va_list(ap->type) || !(lastsym->flags&SDECLARED))
+ goto error;
+
+ for (p = curfun->u.pars; p && *p != lastsym; ++p)
+ /* nothing */;
+ if (!p || *p == NULL || p[1] == NULL || p[1]->type != ellipsistype)
+ warn("second parameter of 'va_start' not last named argument");
+
+ tp = last->type;
+ if (tp == booltype ||
+ tp == chartype || tp == uchartype || tp == schartype ||
+ tp == shortype || tp == ushortype) {
+ warn("last parameter before '...' must not be bool, char or short");
+ }
 
         np = node(OBUILTIN, voidtype, ap, last);
         np->sym = sym;
diff --git a/cc1/code.c b/cc1/code.c
index 0b24c6a..711c4df 100644
--- a/cc1/code.c
+++ b/cc1/code.c
_AT_@ -470,8 +470,6 @@ emitfun(unsigned op, void *arg)
         for (sp = sym->u.pars; sp && *sp; ++sp)
                 emit(ODECL, *sp);
         fputs("\\\n", outfp);
- free(sym->u.pars);
- sym->u.pars = NULL;
 }
 
 static void
diff --git a/cc1/decl.c b/cc1/decl.c
index 4f7d273..85bd150 100644
--- a/cc1/decl.c
+++ b/cc1/decl.c
_AT_@ -901,6 +901,8 @@ decl(void)
         compound(NULL, NULL, NULL);
         popctx();
         emit(OEFUN, NULL);
+ free(sym->u.pars);
+ sym->u.pars = NULL;
         flushtypes();
         curfun = ocurfun;
 }
Received on Mon Feb 13 2017 - 17:00:19 CET