diff options
Diffstat (limited to 'usr.bin/xlint/lint1/tree.c')
| -rw-r--r-- | usr.bin/xlint/lint1/tree.c | 81 |
1 files changed, 46 insertions, 35 deletions
diff --git a/usr.bin/xlint/lint1/tree.c b/usr.bin/xlint/lint1/tree.c index 7729f9a0950..c701c8b060d 100644 --- a/usr.bin/xlint/lint1/tree.c +++ b/usr.bin/xlint/lint1/tree.c @@ -1,4 +1,4 @@ -/* $OpenBSD: tree.c,v 1.38 2006/04/27 20:46:44 otto Exp $ */ +/* $OpenBSD: tree.c,v 1.39 2006/05/03 18:22:41 otto Exp $ */ /* $NetBSD: tree.c,v 1.12 1995/10/02 17:37:57 jpo Exp $ */ /* @@ -33,7 +33,7 @@ */ #ifndef lint -static char rcsid[] = "$OpenBSD: tree.c,v 1.38 2006/04/27 20:46:44 otto Exp $"; +static char rcsid[] = "$OpenBSD: tree.c,v 1.39 2006/05/03 18:22:41 otto Exp $"; #endif #include <stdlib.h> @@ -79,6 +79,7 @@ static tnode_t *chkfarg(tnode_t *, tnode_t *); static tnode_t *parg(farg_t *, tnode_t *); static int chkdbz(op_t, tnode_t *); static void nulleff(tnode_t *); +static int nulleffexpr(tnode_t *); static void chkaidx(tnode_t *, int); static void chkcomp(op_t, tnode_t *, tnode_t *); static void precconf(tnode_t *); @@ -3389,41 +3390,51 @@ nulleff(tnode_t *tn) { if (!hflag) return; - - while (!modtab[tn->tn_op].m_sideeff) { - if (tn->tn_op == CVT && tn->tn_type->t_tspec == VOID) { - tn = tn->tn_left; - } else if (tn->tn_op == LOGAND || tn->tn_op == LOGOR) { - /* - * && and || have a side effect if the right operand - * has a side effect. - */ - tn = tn->tn_right; - } else if (tn->tn_op == QUEST) { - /* - * ? has a side effect if at least one of its right - * operands has a side effect - */ - tn = tn->tn_right; - } else if (tn->tn_op == COLON || tn->tn_op == COMMA) { - /* - * : and , have a side effect if at least one of the - * operands has a side effect - */ - if (modtab[tn->tn_left->tn_op].m_sideeff) { - tn = tn->tn_left; - } else if (modtab[tn->tn_right->tn_op].m_sideeff) { - tn = tn->tn_right; - } else { - break; - } - } else { - break; - } - } - if (!modtab[tn->tn_op].m_sideeff) + if (nulleffexpr(tn)) { /* expression has null effect */ warning(129); + } +} + +static int +nulleffexpr(tnode_t *tn) +{ + int r1, r2; + + if (modtab[tn->tn_op].m_sideeff) + return (0); + + switch (tn->tn_op) { + case CVT: + if (tn->tn_type->t_tspec == VOID) + return (0); + else + return (nulleffexpr(tn->tn_left)); + case LOGAND: + case LOGOR: + /* + * && and || have a null effect if the right operand + * has null effect. + */ + return (nulleffexpr(tn->tn_right)); + case QUEST: + /* + * ? has null effect if both of its right * operands + * have null effect + */ + return (nulleffexpr(tn->tn_right)); + case COLON: + case COMMA: + /* + * : and , have null effect if both of the operands have + * null effect + */ + r1 = nulleffexpr(tn->tn_left); + r2 = nulleffexpr(tn->tn_right); + return (r1 && r2); + default: + return (1); + } } /* |