tree
build_array_ref (tree array, tree index)
{
- if (index == 0)
- {
- error ("subscript missing in array reference");
- return error_mark_node;
- }
-
+ bool swapped = false;
if (TREE_TYPE (array) == error_mark_node
|| TREE_TYPE (index) == error_mark_node)
return error_mark_node;
- if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
+ if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE
+ && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE)
{
- tree rval, type;
-
- /* Subscripting with type char is likely to lose
- on a machine where chars are signed.
- So warn on any machine, but optionally.
- Don't warn for unsigned char since that type is safe.
- Don't warn for signed char because anyone who uses that
- must have done so deliberately. */
- if (warn_char_subscripts
- && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node)
- warning ("array subscript has type %<char%>");
-
- /* Apply default promotions *after* noticing character types. */
- index = default_conversion (index);
-
- /* Require integer *after* promotion, for sake of enums. */
- if (TREE_CODE (TREE_TYPE (index)) != INTEGER_TYPE)
+ tree temp;
+ if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE
+ && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE)
{
- error ("array subscript is not an integer");
+ error ("subscripted value is neither array nor pointer");
return error_mark_node;
}
+ temp = array;
+ array = index;
+ index = temp;
+ swapped = true;
+ }
+
+ if (!INTEGRAL_TYPE_P (TREE_TYPE (index)))
+ {
+ error ("array subscript is not an integer");
+ return error_mark_node;
+ }
+
+ if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE)
+ {
+ error ("subscripted value is pointer to function");
+ return error_mark_node;
+ }
+
+ /* Subscripting with type char is likely to lose on a machine where
+ chars are signed. So warn on any machine, but optionally. Don't
+ warn for unsigned char since that type is safe. Don't warn for
+ signed char because anyone who uses that must have done so
+ deliberately. ??? Existing practice has also been to warn only
+ when the char index is syntactically the index, not for
+ char[array]. */
+ if (warn_char_subscripts && !swapped
+ && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node)
+ warning ("array subscript has type %<char%>");
+
+ /* Apply default promotions *after* noticing character types. */
+ index = default_conversion (index);
+
+ gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE);
+
+ if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
+ {
+ tree rval, type;
/* An array that is indexed by a non-constant
cannot be stored in a register; we must be able to do
| TREE_THIS_VOLATILE (array));
return require_complete_type (fold (rval));
}
+ else
+ {
+ tree ar = default_conversion (array);
- {
- tree ar = default_conversion (array);
- tree ind = default_conversion (index);
-
- /* Do the same warning check as above, but only on the part that's
- syntactically the index and only if it is also semantically
- the index. */
- if (warn_char_subscripts
- && TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE
- && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node)
- warning ("subscript has type %<char%>");
-
- /* Put the integer in IND to simplify error checking. */
- if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
- {
- tree temp = ar;
- ar = ind;
- ind = temp;
- }
-
- if (ar == error_mark_node)
- return ar;
+ if (ar == error_mark_node)
+ return ar;
- if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE
- || TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) == FUNCTION_TYPE)
- {
- error ("subscripted value is neither array nor pointer");
- return error_mark_node;
- }
- if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
- {
- error ("array subscript is not an integer");
- return error_mark_node;
- }
+ gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE);
+ gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE);
- return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, ind, 0),
- "array indexing");
- }
+ return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, index, 0),
+ "array indexing");
+ }
}
\f
/* Build an external reference to identifier ID. FUN indicates
--- /dev/null
+/* Test diagnostics for array references. */
+/* Origin: Joseph Myers <joseph@codesourcery.com> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu89" } */
+
+struct s { char c[1]; };
+struct s f (void);
+_Bool b;
+char c;
+enum e { E } e;
+extern int a[];
+int *p;
+void *pv;
+void (*fp)(void);
+struct si *sip;
+
+void
+g (void)
+{
+ a[b];
+ a[c];
+ a[e];
+ p[b];
+ p[c];
+ p[e];
+ b[a];
+ c[a];
+ e[a];
+ b[p];
+ c[p];
+ e[p];
+ /* These two should be treated the same. In particular, a "neither
+ array nor pointer" bogus warning used to be given for the
+ second. */
+ f().c[0];
+ 0[f().c];
+ /* Various invalid cases. */
+ c[c]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
+ p[1.0]; /* { dg-error "error: array subscript is not an integer" } */
+ 1.0[a]; /* { dg-error "error: array subscript is not an integer" } */
+ fp[0]; /* { dg-error "error: subscripted value is pointer to function" } */
+ 0[fp]; /* { dg-error "error: subscripted value is pointer to function" } */
+ pv[0]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
+ 0[pv]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
+ sip[0]; /* { dg-error "error: invalid use of undefined type 'struct si'" } */
+ /* { dg-error "error: dereferencing pointer to incomplete type" "" { target *-*-* } 45 } */
+ 0[sip]; /* { dg-error "error: invalid use of undefined type 'struct si'" } */
+ /* { dg-error "error: dereferencing pointer to incomplete type" "" { target *-*-* } 47 } */
+}