Module Name: src
Committed By: rillig
Date: Sat Mar 9 14:54:14 UTC 2024
Modified Files:
src/usr.bin/xlint/lint1: tree.c
Log Message:
lint: merge duplicate code for checking array index
To generate a diff of this commit:
cvs rdiff -u -r1.612 -r1.613 src/usr.bin/xlint/lint1/tree.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/xlint/lint1/tree.c
diff -u src/usr.bin/xlint/lint1/tree.c:1.612 src/usr.bin/xlint/lint1/tree.c:1.613
--- src/usr.bin/xlint/lint1/tree.c:1.612 Sat Mar 9 13:54:47 2024
+++ src/usr.bin/xlint/lint1/tree.c Sat Mar 9 14:54:14 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: tree.c,v 1.612 2024/03/09 13:54:47 rillig Exp $ */
+/* $NetBSD: tree.c,v 1.613 2024/03/09 14:54:14 rillig Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID)
-__RCSID("$NetBSD: tree.c,v 1.612 2024/03/09 13:54:47 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.613 2024/03/09 14:54:14 rillig Exp $");
#endif
#include <float.h>
@@ -4327,52 +4327,37 @@ expr(tnode_t *tn, bool vctx, bool cond,
expr_free_all();
}
-/*
- * Checks the range of array indices, if possible.
- * amper is set if only the address of the element is used. This
- * means that the index is allowed to refer to the first element
- * after the array.
- */
+/* If the expression has the form '*(arr + idx)', check the array index. */
static void
-check_array_index(tnode_t *tn, bool amper)
+check_array_index(const tnode_t *indir, bool taking_address)
{
- lint_assert(has_operands(tn));
- const tnode_t *ln = tn->u.ops.left;
- const tnode_t *rn = tn->u.ops.right;
-
- /* We can only check constant indices. */
- if (rn->tn_op != CON)
- return;
-
- /* Return if the left node does not stem from an array. */
- if (ln->tn_op != ADDR)
- return;
- if (ln->u.ops.left->tn_op != STRING && ln->u.ops.left->tn_op != NAME)
- return;
- if (ln->u.ops.left->tn_type->t_tspec != ARRAY)
- return;
+ const tnode_t *plus, *arr, *idx;
- /*
- * For incomplete array types, we can print a warning only if the index
- * is negative.
- */
- if (is_incomplete(ln->u.ops.left->tn_type)
- && rn->u.value.u.integer >= 0)
- return;
+ if (indir->tn_op == INDIR
+ && (plus = indir->u.ops.left, plus->tn_op == PLUS)
+ && plus->u.ops.left->tn_op == ADDR
+ && (arr = plus->u.ops.left->u.ops.left, true)
+ && (arr->tn_op == STRING || arr->tn_op == NAME)
+ && arr->tn_type->t_tspec == ARRAY
+ && (idx = plus->u.ops.right, idx->tn_op == CON)
+ && (!is_incomplete(arr->tn_type) || idx->u.value.u.integer < 0))
+ goto proceed;
+ return;
- int elsz = length_in_bits(ln->tn_type->t_subt, NULL);
+proceed:;
+ int elsz = length_in_bits(arr->tn_type->t_subt, NULL);
if (elsz == 0)
return;
elsz /= CHAR_SIZE;
/* Change the unit of the index from bytes to element size. */
- int64_t con = is_uinteger(rn->tn_type->t_tspec)
- ? (int64_t)((uint64_t)rn->u.value.u.integer / elsz)
- : rn->u.value.u.integer / elsz;
+ int64_t con = is_uinteger(idx->tn_type->t_tspec)
+ ? (int64_t)((uint64_t)idx->u.value.u.integer / elsz)
+ : idx->u.value.u.integer / elsz;
- int dim = ln->u.ops.left->tn_type->u.dimension + (amper ? 1 : 0);
+ int dim = arr->tn_type->u.dimension + (taking_address ? 1 : 0);
- if (!is_uinteger(rn->tn_type->t_tspec) && con < 0)
+ if (!is_uinteger(idx->tn_type->t_tspec) && con < 0)
/* array subscript cannot be negative: %ld */
warning(167, (long)con);
else if (dim > 0 && (uint64_t)con >= (uint64_t)dim)
@@ -4389,15 +4374,7 @@ check_expr_addr(const tnode_t *ln, bool
mark_as_set(ln->u.sym);
mark_as_used(ln->u.sym, fcall, szof);
}
- if (ln->tn_op == INDIR && ln->u.ops.left->tn_op == PLUS)
- check_array_index(ln->u.ops.left, true);
-}
-
-static void
-check_expr_load(const tnode_t *ln)
-{
- if (ln->tn_op == INDIR && ln->u.ops.left->tn_op == PLUS)
- check_array_index(ln->u.ops.left, false);
+ check_array_index(ln, true);
}
/*
@@ -4439,9 +4416,7 @@ check_expr_assign(const tnode_t *ln, boo
if (ln->u.sym->s_scl == EXTERN)
outusg(ln->u.sym);
}
- if (ln->tn_op == INDIR && ln->u.ops.left->tn_op == PLUS)
- /* check the range of array indices */
- check_array_index(ln->u.ops.left, false);
+ check_array_index(ln, false);
}
static void
@@ -4463,7 +4438,7 @@ check_expr_op(op_t op, const tnode_t *ln
check_expr_addr(ln, szof, fcall);
break;
case LOAD:
- check_expr_load(ln);
+ check_array_index(ln, false);
/* FALLTHROUGH */
case INCBEF:
case DECBEF:
