[src/trunk]: src/usr.bin/xlint/lint1 make lint recognize constant shift value...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ae5949590562
branches:  trunk
changeset: 753224:ae5949590562
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Mar 21 00:02:13 2010 +0000

description:
make lint recognize constant shift values and not warn if the number of bits
shifted results in a narrower type.

diffstat:

 usr.bin/xlint/lint1/tree.c |  46 ++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 42 insertions(+), 4 deletions(-)

diffs (83 lines):

diff -r 75ca5f27b777 -r ae5949590562 usr.bin/xlint/lint1/tree.c
--- a/usr.bin/xlint/lint1/tree.c        Sat Mar 20 23:31:27 2010 +0000
+++ b/usr.bin/xlint/lint1/tree.c        Sun Mar 21 00:02:13 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tree.c,v 1.62 2009/10/02 21:04:03 christos Exp $       */
+/*     $NetBSD: tree.c,v 1.63 2010/03/21 00:02:13 christos Exp $       */
 
 /*
  * Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: tree.c,v 1.62 2009/10/02 21:04:03 christos Exp $");
+__RCSID("$NetBSD: tree.c,v 1.63 2010/03/21 00:02:13 christos Exp $");
 #endif
 
 #include <stdlib.h>
@@ -1513,6 +1513,8 @@
 {
        tnode_t *ntn;
        tspec_t t;
+       size_t l;
+       uint64_t rnum;
 
        ntn = getnode();
 
@@ -1521,7 +1523,40 @@
        ntn->tn_left = ln;
        ntn->tn_right = rn;
 
-       if (op == STAR || op == FSEL) {
+       switch (op) {
+       case SHR:
+               if (rn->tn_op != CON)
+                       break;
+               rnum = rn->tn_val->v_quad;
+               l = tsize(ln->tn_type) / CHAR_BIT;
+               t = ln->tn_type->t_tspec;
+               switch (l) {
+               case 8:
+                       if (rnum >= 56)
+                               t = UCHAR;
+                       else if (rnum >= 48)
+                               t = USHORT;
+                       else if (rnum >= 32)
+                               t = UINT;
+                       break;
+               case 4:
+                       if (rnum >= 24)
+                               t = UCHAR;
+                       else if (rnum >= 16)
+                               t = USHORT;
+                       break;
+               case 2:
+                       if (rnum >= 8)
+                               t = UCHAR;
+                       break;
+               default:
+                       break;
+               }
+               if (t != ln->tn_type->t_tspec)
+                       ntn->tn_type->t_tspec = t;
+               break;
+       case STAR:
+       case FSEL:
                if (ln->tn_type->t_tspec == PTR) {
                        t = ln->tn_type->t_subt->t_tspec;
                        if (t != FUNC && t != VOID)
@@ -1529,9 +1564,12 @@
                } else {
                        LERROR("mktnode()");
                }
+               break;
+       default:
+               break;
        }
 
-       return (ntn);
+       return ntn;
 }
 
 /*