lint: fix bugs in dprint_node in debug mode (since today)

The node was dereferenced before the null check.  GCC 5.5 didn't warn
about this obvious bug, not even with -Wall -Wextra -O2.  Such a case
didn't occur though in the few tests that this function was used in.

The indentation for the nested nodes only needs to be set for a few
lines of code, make this region as small as possible.

There are nodes that use both tn_left and tn_right, even though they are
not defined as binary operators.  An example is CALL, for which tn_left
is the address of the function name and tn_right, which are the
arguments, linked via PUSH nodes.  CALL is not a binary operator since
it doesn't do any calculations with its arguments.
This commit is contained in:
rillig 2021-01-04 21:30:06 +00:00
parent 4f7d5d5f25
commit c48d8a0ff1
1 changed files with 9 additions and 44 deletions

View File

@ -1,4 +1,4 @@
/* $NetBSD: tree.c,v 1.125 2021/01/04 21:17:31 rillig Exp $ */
/* $NetBSD: tree.c,v 1.126 2021/01/04 21:30:06 rillig 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 1.125 2021/01/04 21:17:31 rillig Exp $");
__RCSID("$NetBSD: tree.c,v 1.126 2021/01/04 21:30:06 rillig Exp $");
#endif
#include <float.h>
@ -91,64 +91,27 @@ static void check_precedence_confusion(tnode_t *);
extern sig_atomic_t fpe;
#if 0
static char *
dumpnode(char *buf, size_t len, tnode_t *tn) {
const char *n = getopname(tn->tn_op);
const char *s;
switch (tn->tn_op) {
case NAME:
s = tn->tn_sym->s_name;
break;
case CON:
case STRING:
s = "*"; /* todo */
break;
default:
s = NULL;
break;
}
char lb[1024];
char rb[1024];
if (s == NULL && tn->tn_left != NULL)
dumpnode(lb, sizeof(lb), tn->tn_left);
else
strcpy(lb, "(null)");
if (s == NULL && tn->tn_right != NULL)
dumpnode(rb, sizeof(rb), tn->tn_right);
else
strcpy(rb, "(null)");
snprintf(buf, len, "%s: (%s) = %s [%s, %s]", n,
type_name(tn->tn_type), s, lb, rb);
return buf;
}
#endif
#ifdef DEBUG
static void
dprint_node(const tnode_t *tn)
{
static int indent = 0;
op_t op = tn->tn_op;
op_t op;
if (tn == NULL) {
printf("%*s" "null\n", indent, "");
return;
}
op = tn->tn_op;
printf("%*s%s: %s%s%s",
indent, "",
op == CVT && !tn->tn_cast ? "convert" :
op == NAME ? "name" : getopname(op),
type_name(tn->tn_type), tn->tn_lvalue ? " lvalue" : "",
tn->tn_parenthesized ? " ()" : "");
indent += 2;
if (op == NAME)
printf(" %s\n", tn->tn_sym->s_name);
else if (op == CON)
@ -157,11 +120,13 @@ dprint_node(const tnode_t *tn)
printf(" length=%zu\n", tn->tn_string->st_len);
else {
printf("\n");
indent += 2;
dprint_node(tn->tn_left);
if (modtab[op].m_binary)
if (modtab[op].m_binary || tn->tn_right != NULL)
dprint_node(tn->tn_right);
indent -= 2;
}
indent -= 2;
}
#else
/*ARGSUSED*/