return expr;
}
-/* Return whether EXPR is a declaration whose address can never be
- NULL. */
+/* Return whether EXPR is a declaration whose address can never be NULL.
+ The address of the first struct member could be NULL only if it were
+ accessed through a NULL pointer, and such an access would be invalid. */
bool
decl_with_nonnull_addr_p (const_tree expr)
{
return (DECL_P (expr)
- && (TREE_CODE (expr) == PARM_DECL
+ && (TREE_CODE (expr) == FIELD_DECL
+ || TREE_CODE (expr) == PARM_DECL
|| TREE_CODE (expr) == LABEL_DECL
|| !DECL_WEAK (expr)));
}
case ADDR_EXPR:
{
tree inner = TREE_OPERAND (expr, 0);
- if (decl_with_nonnull_addr_p (inner))
+ if (decl_with_nonnull_addr_p (inner)
+ /* Check both EXPR and INNER for suppression. */
+ && !warning_suppressed_p (expr, OPT_Waddress)
+ && !warning_suppressed_p (inner, OPT_Waddress))
{
- /* Common Ada programmer's mistake. */
+ /* Common Ada programmer's mistake. */
warning_at (location,
OPT_Waddress,
"the address of %qD will always evaluate as %<true%>",
inner);
+ suppress_warning (inner, OPT_Waddress);
return truthvalue_true_node;
}
break;
break;
/* If this isn't narrowing the argument, we can ignore it. */
if (TYPE_PRECISION (totype) >= TYPE_PRECISION (fromtype))
- return c_common_truthvalue_conversion (location,
- TREE_OPERAND (expr, 0));
+ {
+ tree op0 = TREE_OPERAND (expr, 0);
+ if ((TREE_CODE (fromtype) == POINTER_TYPE
+ && TREE_CODE (totype) == INTEGER_TYPE)
+ || warning_suppressed_p (expr, OPT_Waddress))
+ /* Suppress -Waddress for casts to intptr_t, propagating
+ any suppression from the enclosing expression to its
+ operand. */
+ suppress_warning (op0, OPT_Waddress);
+ return c_common_truthvalue_conversion (location, op0);
+ }
}
break;
return build3 (VEC_COND_EXPR, type, cmp, minus_one_vec, zero_vec);
}
+/* Possibly warn about an address of OP never being NULL in a comparison
+ operation CODE involving null. */
+
+static void
+maybe_warn_for_null_address (location_t loc, tree op, tree_code code)
+{
+ if (!warn_address || warning_suppressed_p (op, OPT_Waddress))
+ return;
+
+ if (TREE_CODE (op) == NOP_EXPR)
+ {
+ /* Allow casts to intptr_t to suppress the warning. */
+ tree type = TREE_TYPE (op);
+ if (TREE_CODE (type) == INTEGER_TYPE)
+ return;
+ op = TREE_OPERAND (op, 0);
+ }
+
+ if (TREE_CODE (op) == POINTER_PLUS_EXPR)
+ {
+ /* Allow a cast to void* to suppress the warning. */
+ tree type = TREE_TYPE (TREE_TYPE (op));
+ if (VOID_TYPE_P (type))
+ return;
+
+ /* Adding any value to a null pointer, including zero, is undefined
+ in C. This includes the expression &p[0] where p is the null
+ pointer, although &p[0] will have been folded to p by this point
+ and so not diagnosed. */
+ if (code == EQ_EXPR)
+ warning_at (loc, OPT_Waddress,
+ "the comparison will always evaluate as %<false%> "
+ "for the pointer operand in %qE must not be NULL",
+ op);
+ else
+ warning_at (loc, OPT_Waddress,
+ "the comparison will always evaluate as %<true%> "
+ "for the pointer operand in %qE must not be NULL",
+ op);
+
+ return;
+ }
+
+ if (TREE_CODE (op) != ADDR_EXPR)
+ return;
+
+ op = TREE_OPERAND (op, 0);
+
+ if (TREE_CODE (op) == IMAGPART_EXPR
+ || TREE_CODE (op) == REALPART_EXPR)
+ {
+ /* The address of either complex part may not be null. */
+ if (code == EQ_EXPR)
+ warning_at (loc, OPT_Waddress,
+ "the comparison will always evaluate as %<false%> "
+ "for the address of %qE will never be NULL",
+ op);
+ else
+ warning_at (loc, OPT_Waddress,
+ "the comparison will always evaluate as %<true%> "
+ "for the address of %qE will never be NULL",
+ op);
+ return;
+ }
+
+ /* Set to true in the loop below if OP dereferences is operand.
+ In such a case the ultimate target need not be a decl for
+ the null [in]equality test to be constant. */
+ bool deref = false;
+
+ /* Get the outermost array or object, or member. */
+ while (handled_component_p (op))
+ {
+ if (TREE_CODE (op) == COMPONENT_REF)
+ {
+ /* Get the member (its address is never null). */
+ op = TREE_OPERAND (op, 1);
+ break;
+ }
+
+ /* Get the outer array/object to refer to in the warning. */
+ op = TREE_OPERAND (op, 0);
+ deref = true;
+ }
+
+ if ((!deref && !decl_with_nonnull_addr_p (op))
+ || from_macro_expansion_at (loc))
+ return;
+
+ if (code == EQ_EXPR)
+ warning_at (loc, OPT_Waddress,
+ "the comparison will always evaluate as %<false%> "
+ "for the address of %qE will never be NULL",
+ op);
+ else
+ warning_at (loc, OPT_Waddress,
+ "the comparison will always evaluate as %<true%> "
+ "for the address of %qE will never be NULL",
+ op);
+
+ if (DECL_P (op))
+ inform (DECL_SOURCE_LOCATION (op), "%qD declared here", op);
+}
+
/* Build a binary-operation expression without default conversions.
CODE is the kind of expression to build.
LOCATION is the operator's location.
short_compare = 1;
else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
{
- if (TREE_CODE (op0) == ADDR_EXPR
- && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0))
- && !from_macro_expansion_at (location))
- {
- if (code == EQ_EXPR)
- warning_at (location,
- OPT_Waddress,
- "the comparison will always evaluate as %<false%> "
- "for the address of %qD will never be NULL",
- TREE_OPERAND (op0, 0));
- else
- warning_at (location,
- OPT_Waddress,
- "the comparison will always evaluate as %<true%> "
- "for the address of %qD will never be NULL",
- TREE_OPERAND (op0, 0));
- }
+ maybe_warn_for_null_address (location, op0, code);
result_type = type0;
}
else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
{
- if (TREE_CODE (op1) == ADDR_EXPR
- && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0))
- && !from_macro_expansion_at (location))
- {
- if (code == EQ_EXPR)
- warning_at (location,
- OPT_Waddress,
- "the comparison will always evaluate as %<false%> "
- "for the address of %qD will never be NULL",
- TREE_OPERAND (op1, 0));
- else
- warning_at (location,
- OPT_Waddress,
- "the comparison will always evaluate as %<true%> "
- "for the address of %qD will never be NULL",
- TREE_OPERAND (op1, 0));
- }
+ maybe_warn_for_null_address (location, op1, code);
result_type = type1;
}
else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
|| warning_suppressed_p (op, OPT_Waddress))
return;
+ if (TREE_CODE (op) == NON_DEPENDENT_EXPR)
+ op = TREE_OPERAND (op, 0);
+
tree cop = fold_for_warn (op);
- if (TREE_CODE (cop) == ADDR_EXPR
- && decl_with_nonnull_addr_p (TREE_OPERAND (cop, 0))
- && !warning_suppressed_p (cop, OPT_Waddress))
- warning_at (location, OPT_Waddress, "the address of %qD will never "
- "be NULL", TREE_OPERAND (cop, 0));
+ if (TREE_CODE (cop) == NON_LVALUE_EXPR)
+ /* Unwrap the expression for C++ 98. */
+ cop = TREE_OPERAND (cop, 0);
- if (CONVERT_EXPR_P (op)
+ if (TREE_CODE (cop) == PTRMEM_CST)
+ {
+ /* The address of a nonstatic data member is never null. */
+ warning_at (location, OPT_Waddress,
+ "the address %qE will never be NULL",
+ cop);
+ return;
+ }
+
+ if (TREE_CODE (cop) == NOP_EXPR)
+ {
+ /* Allow casts to intptr_t to suppress the warning. */
+ tree type = TREE_TYPE (cop);
+ if (TREE_CODE (type) == INTEGER_TYPE)
+ return;
+
+ STRIP_NOPS (cop);
+ }
+
+ bool warned = false;
+ if (TREE_CODE (cop) == ADDR_EXPR)
+ {
+ cop = TREE_OPERAND (cop, 0);
+
+ /* Set to true in the loop below if OP dereferences its operand.
+ In such a case the ultimate target need not be a decl for
+ the null [in]equality test to be necessarily constant. */
+ bool deref = false;
+
+ /* Get the outermost array or object, or member. */
+ while (handled_component_p (cop))
+ {
+ if (TREE_CODE (cop) == COMPONENT_REF)
+ {
+ /* Get the member (its address is never null). */
+ cop = TREE_OPERAND (cop, 1);
+ break;
+ }
+
+ /* Get the outer array/object to refer to in the warning. */
+ cop = TREE_OPERAND (cop, 0);
+ deref = true;
+ }
+
+ if ((!deref && !decl_with_nonnull_addr_p (cop))
+ || from_macro_expansion_at (location)
+ || warning_suppressed_p (cop, OPT_Waddress))
+ return;
+
+ warned = warning_at (location, OPT_Waddress,
+ "the address of %qD will never be NULL", cop);
+ op = cop;
+ }
+ else if (TREE_CODE (cop) == POINTER_PLUS_EXPR)
+ {
+ /* Adding zero to the null pointer is well-defined in C++. When
+ the offset is unknown (i.e., not a constant) warn anyway since
+ it's less likely that the pointer operand is null than not. */
+ tree off = TREE_OPERAND (cop, 1);
+ if (!integer_zerop (off)
+ && !warning_suppressed_p (cop, OPT_Waddress))
+ warning_at (location, OPT_Waddress, "comparing the result of pointer "
+ "addition %qE and NULL", cop);
+ return;
+ }
+ else if (CONVERT_EXPR_P (op)
&& TYPE_REF_P (TREE_TYPE (TREE_OPERAND (op, 0))))
{
- tree inner_op = op;
- STRIP_NOPS (inner_op);
+ STRIP_NOPS (op);
- if (DECL_P (inner_op))
- warning_at (location, OPT_Waddress,
- "the compiler can assume that the address of "
- "%qD will never be NULL", inner_op);
+ if (DECL_P (op))
+ warned = warning_at (location, OPT_Waddress,
+ "the compiler can assume that the address of "
+ "%qD will never be NULL", op);
}
+
+ if (warned && DECL_P (op))
+ inform (DECL_SOURCE_LOCATION (op), "%qD declared here", op);
}
/* Warn about [expr.arith.conv]/2: If one operand is of enumeration type and
op1 = cp_convert (TREE_TYPE (op0), op1, complain);
}
result_type = TREE_TYPE (op0);
+
+ warn_for_null_address (location, orig_op0, complain);
}
else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (orig_op0))
return cp_build_binary_op (location, code, op1, op0, complain);
@item -Waddress
@opindex Waddress
@opindex Wno-address
-Warn about suspicious uses of memory addresses. These include using
-the address of a function in a conditional expression, such as
-@code{void func(void); if (func)}, and comparisons against the memory
-address of a string literal, such as @code{if (x == "abc")}. Such
-uses typically indicate a programmer error: the address of a function
-always evaluates to true, so their use in a conditional usually
-indicate that the programmer forgot the parentheses in a function
-call; and comparisons against string literals result in unspecified
-behavior and are not portable in C, so they usually indicate that the
-programmer intended to use @code{strcmp}. This warning is enabled by
-@option{-Wall}.
+Warn about suspicious uses of address expressions. These include comparing
+the address of a function or a declared object to the null pointer constant
+such as in
+@smallexample
+void f (void);
+void g (void)
+@{
+ if (!func) // warning: expression evaluates to false
+ abort ();
+@}
+@end smallexample
+comparisons of a pointer to a string literal, such as in
+@smallexample
+void f (const char *x)
+@{
+ if (x == "abc") // warning: expression evaluates to false
+ puts ("equal");
+@}
+@end smallexample
+and tests of the results of pointer addition or subtraction for equality
+to null, such as in
+@smallexample
+void f (const int *p, int i)
+@{
+ return p + i == NULL;
+@}
+@end smallexample
+Such uses typically indicate a programmer error: the address of most
+functions and objects necessarily evaluates to true (the exception are
+weak symbols), so their use in a conditional might indicate missing
+parentheses in a function call or a missing dereference in an array
+expression. The subset of the warning for object pointers can be
+suppressed by casting the pointer operand to an integer type such
+as @code{inptr_t} or @code{uinptr_t}.
+Comparisons against string literals result in unspecified behavior
+and are not portable, and suggest the intent was to call @code{strcmp}.
+@option{-Waddress} warning is enabled by @option{-Wall}.
@item -Wno-address-of-packed-member
@opindex Waddress-of-packed-member
}
}
- if (array->shape && array->shape[dimen])
+ if (array->shape)
{
mpz_init_set (*result, array->shape[dimen]);
return true;
if (info->shape)
{
- gcc_assert (info->shape[dim]);
/* The frontend has worked out the size for us. */
if (!loopspec[n]
|| !specinfo->shape
output_mangled_typename (output_header, s);
oprintf (output_header, "(X) do { \\\n");
oprintf (output_header,
- " if (X != NULL) gt_%sx_%s (X);\\\n", wtd->prefix,
- s_id_for_tag);
+ " if ((intptr_t)(X) != 0) gt_%sx_%s (X);\\\n",
+ wtd->prefix, s_id_for_tag);
oprintf (output_header, " } while (0)\n");
for (opt = s->u.s.opt; opt; opt = opt->next)
routine can take the address of RES rather than the address of
a temporary.
- The dummy comparison against a null C * is just a way of checking
+ The dummy self-comparison against C * is just a way of checking
that C gives the right type. */
#define POLY_SET_COEFF(C, RES, I, VALUE) \
- ((void) (&(RES).coeffs[0] == (C *) 0), \
+ ((void) (&(RES).coeffs[0] == (C *) (void *) &(RES).coeffs[0]), \
wi::int_traits<C>::precision_type == wi::FLEXIBLE_PRECISION \
? (void) ((RES).coeffs[I] = VALUE) \
: (void) ((RES).coeffs[I].~C (), new (&(RES).coeffs[I]) C (VALUE)))
--- /dev/null
+/* PR c/102103 - missing warning comparing array address to null
+ { dg-do compile }
+ { dg-options "-Wall" } */
+
+typedef __INTPTR_TYPE__ intptr_t;
+typedef __UINTPTR_TYPE__ uintptr_t;
+
+#ifndef __cplusplus
+# define bool _Bool
+#endif
+
+struct S { void *p, *a1[2], *a2[2][2]; } s, *p;
+
+extern const void *a1[2];
+extern void *a2[2][2], *ax[];
+
+void T (bool);
+
+void test_array_eq_0 (int i)
+{
+ // Verify that casts intptr_t suppress the warning.
+ T ((intptr_t)a1 == 0);
+ T ((uintptr_t)a1 == 0);
+ T (a1 == 0); // { dg-warning "-Waddress" }
+ T (0 == &a1); // { dg-warning "-Waddress" }
+ // Verify that casts to other pointer types don't suppress it.
+ T ((void *)a1 == 0); // { dg-warning "-Waddress" }
+ T ((char *)a1 == 0); // { dg-warning "-Waddress" }
+ T (a1[0] == 0);
+ T (0 == (intptr_t)&a1[0]);
+ T (0 == &a1[0]); // { dg-warning "-Waddress" }
+ T (a1[i] == 0);
+ T (0 == (uintptr_t)&a1[i]);
+ T (0 == &a1[i]); // { dg-warning "-Waddress" }
+
+ T ((intptr_t)a2 == 0);
+ T (a2 == 0); // { dg-warning "-Waddress" }
+ T (0 == &a2); // { dg-warning "-Waddress" }
+ T (a2[0] == 0); // { dg-warning "-Waddress" }
+ T (0 == &a1[0]); // { dg-warning "-Waddress" }
+ T (a2[i] == 0); // { dg-warning "-Waddress" }
+ T (0 == &a2[i]); // { dg-warning "-Waddress" }
+ T (a2[0][0] == 0);
+ T (0 == &a2[0][0]); // { dg-warning "-Waddress" }
+ T (&ax == 0); // { dg-warning "-Waddress" }
+ T (0 == &ax); // { dg-warning "-Waddress" }
+ T (&ax[0] == 0); // { dg-warning "-Waddress" }
+ T (0 == ax[0]);
+}
+
+
+void test_array_neq_0 (int i)
+{
+ // Verify that casts to intptr_t suppress the warning.
+ T ((uintptr_t)a1);
+
+ T (a1); // { dg-warning "-Waddress" }
+ T ((void *)a1); // { dg-warning "-Waddress" }
+ T (&a1 != 0); // { dg-warning "-Waddress" }
+ T (a1[0]);
+ T (&a1[0] != 0); // { dg-warning "-Waddress" }
+ T (a1[i]);
+ T (&a1[i] != 0); // { dg-warning "-Waddress" }
+
+ T ((intptr_t)a2);
+ T (a2); // { dg-warning "-Waddress" }
+ T ((void *)a2); // { dg-warning "-Waddress" }
+ T ((char *)a2); // { dg-warning "-Waddress" }
+ T (&a2 != 0); // { dg-warning "-Waddress" }
+ T (a2[0]); // { dg-warning "-Waddress" }
+ T (&a1[0] != 0); // { dg-warning "-Waddress" }
+ T (a2[i]); // { dg-warning "-Waddress" }
+ T (&a2[i] != 0); // { dg-warning "-Waddress" }
+ T (a2[0][0]);
+ T (&a2[0][0] != 0); // { dg-warning "-Waddress" }
+}
+
+
+void test_member_array_eq_0 (int i)
+{
+ // Verify that casts to intptr_t suppress the warning.
+ T ((intptr_t)s.a1 == 0);
+ T (s.a1 == 0); // { dg-warning "-Waddress" }
+ T (0 == &a1); // { dg-warning "-Waddress" }
+ T (s.a1[0] == 0);
+ T ((void*)s.a1); // { dg-warning "-Waddress" }
+ T (0 == &a1[0]); // { dg-warning "-Waddress" }
+ T (s.a1[i] == 0);
+ T (0 == &a1[i]); // { dg-warning "-Waddress" }
+
+ T ((uintptr_t)s.a2 == 0);
+ T (s.a2 == 0); // { dg-warning "-Waddress" }
+ T (0 == &a2); // { dg-warning "-Waddress" }
+ T ((void *)s.a2 == 0);// { dg-warning "-Waddress" }
+ T (s.a2[0] == 0); // { dg-warning "-Waddress" }
+ T (0 == &a1[0]); // { dg-warning "-Waddress" }
+ T (s.a2[i] == 0); // { dg-warning "-Waddress" }
+ T (0 == &a2[i]); // { dg-warning "-Waddress" }
+ T (s.a2[0][0] == 0);
+ T (0 == &a2[0][0]); // { dg-warning "-Waddress" }
+}
+
+
+void test_member_array_neq_0 (int i)
+{
+ // Verify that casts to intptr_t suppress the warning.
+ T ((uintptr_t)s.a1);
+ T (s.a1); // { dg-warning "-Waddress" }
+ T (&s.a1 != 0); // { dg-warning "-Waddress" }
+ T ((void *)&s.a1[0]); // { dg-warning "-Waddress" }
+ T (s.a1[0]);
+ T (&s.a1[0] != 0); // { dg-warning "-Waddress" }
+ T (s.a1[i]);
+ T (&s.a1[i] != 0); // { dg-warning "-Waddress" }
+
+ T ((intptr_t)s.a2);
+ T (s.a2); // { dg-warning "-Waddress" }
+ T (&s.a2 != 0); // { dg-warning "-Waddress" }
+ T (s.a2[0]); // { dg-warning "-Waddress" }
+ T (&s.a1[0] != 0); // { dg-warning "-Waddress" }
+ T (s.a2[i]); // { dg-warning "-Waddress" }
+ T (&s.a2[i] != 0); // { dg-warning "-Waddress" }
+ T (s.a2[0][0]);
+ T (&s.a2[0][0] != 0); // { dg-warning "-Waddress" }
+}
--- /dev/null
+/* PR c/102103 - missing warning comparing array address to null
+ { dg-do compile }
+ { dg-options "-Wall" } */
+
+typedef __INTPTR_TYPE__ intptr_t;
+typedef __INTPTR_TYPE__ uintptr_t;
+
+extern char *ax[], *a2[][2];
+
+void T (int);
+
+void test_ax_plus_eq_0 (int i)
+{
+ // Verify that casts to intptr_t suppress the warning.
+ T ((intptr_t)(ax + 0) == 0);
+ T ((uintptr_t)(ax + 1) == 0);
+
+ T (ax + 0 == 0); // { dg-warning "-Waddress" }
+ T (&ax[0] == 0); // { dg-warning "-Waddress" }
+ T (ax - 1 == 0); // { dg-warning "-Waddress" }
+ T (0 == &ax[-1]); // { dg-warning "-Waddress" }
+ T ((void *)(&ax[0] + 2) == 0); // { dg-warning "-Waddress" }
+ T (&ax[0] + 2 == 0); // { dg-warning "-Waddress" }
+ T (ax + 3 == 0); // { dg-warning "-Waddress" }
+ T (0 == &ax[-4]); // { dg-warning "-Waddress" }
+ T (ax - i == 0); // { dg-warning "-Waddress" }
+ T (&ax[i] == 0); // { dg-warning "-Waddress" }
+ T (0 == &ax[1] + i); // { dg-warning "-Waddress" }
+}
+
+void test_a2_plus_eq_0 (int i)
+{
+ // Verify that casts to intptr_t suppress the warning.
+ T ((intptr_t)(a2 + 0) == 0);
+ T ((uintptr_t)(a2 + 1) == 0);
+
+ T (a2 + 0 == 0); // { dg-warning "-Waddress" }
+ // Verify that a cast to another pointer type doesn't suppress it.
+ T ((void*)(a2 + 0) == 0); // { dg-warning "-Waddress" }
+ T ((char*)a2 + 1 == 0); // { dg-warning "-Waddress" }
+ T (&a2[0] == 0); // { dg-warning "-Waddress" }
+ T (a2 - 1 == 0); // { dg-warning "-Waddress" }
+ T (0 == &a2[-1]); // { dg-warning "-Waddress" }
+ T (a2 + 2 == 0); // { dg-warning "-Waddress" }
+ T (0 == &a2[-2]); // { dg-warning "-Waddress" }
+ T (a2 - i == 0); // { dg-warning "-Waddress" }
+ T (&a2[i] == 0); // { dg-warning "-Waddress" }
+}
+
+// Exercise a pointer.
+void test_p_plus_eq_0 (int *p, int i)
+{
+ /* P + 0 and equivalently &P[0] are invalid for a null P but they're
+ folded to p before the warning has a chance to trigger. */
+ T (p + 0 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
+ T (&p[0] == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
+
+ T (p - 1 == 0); // { dg-warning "-Waddress" }
+ T (0 == &p[-1]); // { dg-warning "-Waddress" }
+ T (p + 2 == 0); // { dg-warning "-Waddress" }
+ T (0 == &p[-2]); // { dg-warning "-Waddress" }
+ T (p - i == 0); // { dg-warning "-Waddress" }
+ T (&p[i] == 0); // { dg-warning "-Waddress" }
+}
+
+// Exercise pointer to array.
+void test_pa_plus_eq_0 (int (*p)[], int (*p2)[][2], int i)
+{
+ // The array pointer may be null.
+ T (*p == 0);
+ /* &**P is equivalent to *P and might be the result od macro expansion.
+ Verify it doesn't cause a warning. */
+ T (&**p == 0);
+
+ /* *P + 0 is invalid but folded to *P before the warning has a chance
+ to trigger. */
+ T (*p + 0 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
+
+ T (&(*p)[0] == 0); // { dg-warning "-Waddress" }
+ T (*p - 1 == 0); // { dg-warning "-Waddress" }
+ T (0 == &(*p)[-1]); // { dg-warning "-Waddress" }
+ T (*p + 2 == 0); // { dg-warning "-Waddress" }
+ T (0 == &(*p)[-2]); // { dg-warning "-Waddress" }
+ T (*p - i == 0); // { dg-warning "-Waddress" }
+ T (&(*p)[i] == 0); // { dg-warning "-Waddress" }
+
+
+ /* Similar to the above but for a pointer to a two-dimensional array,
+ referring to the higher-level element (i.e., an array itself). */
+ T (*p2 == 0);
+ T (**p2 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
+ T (&**p2 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
+ T (&***p2 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
+ T (&**p2 == 0);
+
+ T (*p2 + 0 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
+ T (&(*p2)[0] == 0); // { dg-warning "-Waddress" }
+ T (&(*p2)[0][1] == 0); // { dg-warning "-Waddress" }
+ T (*p2 - 1 == 0); // { dg-warning "-Waddress" }
+ T (0 == &(*p2)[-1]); // { dg-warning "-Waddress" }
+ T (0 == &(*p2)[1][2]); // { dg-warning "-Waddress" }
+ T (*p2 + 2 == 0); // { dg-warning "-Waddress" }
+ T (0 == &(*p2)[-2]); // { dg-warning "-Waddress" }
+ T (*p2 - i == 0); // { dg-warning "-Waddress" }
+ T (&(*p2)[i] == 0); // { dg-warning "-Waddress" }
+}
constexpr int *p1 = &i + 1;
#pragma GCC diagnostic push
+// Suppress warning: ordered comparison of pointer with integer zero.
#pragma GCC diagnostic ignored "-Wextra"
-// Suppress warning: ordered comparison of pointer with integer zero
+// Also suppress -Waddress for comparisons of constant addresses to
+// to null.
+#pragma GCC diagnostic ignored "-Waddress"
constexpr bool b0 = p1; // { dg-error "not a constant expression" }
constexpr bool b1 = p1 == 0; // { dg-error "not a constant expression" }
--- /dev/null
+/* PR c/102103 - missing warning comparing array address to null
+ { dg-do compile }
+ { dg-options "-Wall" } */
+
+#if __cplusplus < 201103L
+# define nullptr __null
+#endif
+
+struct A
+{
+ void f ();
+ virtual void vf ();
+ virtual void pvf () = 0;
+
+ void sf ();
+
+ int *p;
+ int a[2];
+};
+
+void T (bool);
+
+void warn_memptr_if ()
+{
+ // Exercise warnings for addresses of nonstatic member functions.
+ if (&A::f == 0) // { dg-warning "the address '&A::f'" }
+ T (0);
+
+ if (&A::vf) // { dg-warning "-Waddress" }
+ T (0);
+
+ if (&A::pvf != 0) // { dg-warning "-Waddress" }
+ T (0);
+
+ // Exercise warnings for addresses of static member functions.
+ if (&A::sf == 0) // { dg-warning "-Waddress" }
+ T (0);
+
+ if (&A::sf) // { dg-warning "-Waddress" }
+ T (0);
+
+ // Exercise warnings for addresses of nonstatic data members.
+ if (&A::p == 0) // { dg-warning "the address '&A::p'" }
+ T (0);
+
+ if (&A::a == nullptr) // { dg-warning "-Waddress" }
+ T (0);
+}
+
+void warn_memptr_bool ()
+{
+ // Exercise warnings for addresses of nonstatic member functions.
+ T (&A::f == 0); // { dg-warning "-Waddress" }
+ T (&A::vf); // { dg-warning "-Waddress" }
+ T (&A::pvf != 0); // { dg-warning "-Waddress" }
+
+ // Exercise warnings for addresses of static member functions.
+ T (&A::sf == 0); // { dg-warning "-Waddress" }
+ T (&A::sf); // { dg-warning "-Waddress" }
+
+ // Exercise warnings for addresses of nonstatic data members.
+ T (&A::p == 0); // { dg-warning "-Waddress" }
+ T (&A::a == nullptr); // { dg-warning "-Waddress" }
+}
+
+
+/* Verify that no warnings are issued for a dependent expression in
+ a template. */
+
+template <int>
+struct B
+{
+ // This is why.
+ struct F { void* operator& () const { return 0; } } f;
+};
+
+template <class Type, int N>
+void nowarn_dependent (Type targ)
+{
+ T (&Type::x == 0);
+ T (&targ == 0);
+
+ Type tarr[1];
+ T (&tarr[0] == nullptr);
+
+ T (&B<N>::f == 0);
+
+ /* Like in the case above, the address-of operator could be a member
+ of B<N>::vf that returns zero. */
+ T (&B<N>::vf);
+ T (&B<N>::pvf != 0);
+ T (&B<N>::p == 0);
+ T (&B<N>::a == 0);
+}
+
+
+/* Verify that in an uninstantiated template warnings are not issued
+ for dependent expressions but are issued otherwise. */
+
+template <class Type>
+void warn_non_dependent (Type targ, Type *tptr, int i)
+{
+ /* The address of a pointer to a dependent type cannot be null but
+ the warning doesn't have a chance to see it. */
+ T (&tptr == 0); // { dg-warning "-Waddress" "pr102378" { xfail *-*-* } }
+ T (&i == 0); // { dg-warning "-Waddress" }
+
+ int iarr[1];
+ T (&iarr == 0); // { dg-warning "-Waddress" }
+ T (&*iarr != 0); // { dg-warning "-Waddress" "pr102378" { xfail *-*-* } }
+ T (&iarr[0] == 0); // { dg-warning "-Waddress" }
+
+ Type tarr[1];
+ T (&tarr == nullptr); // { dg-warning "-Waddress" "pr102378" { xfail *-*-* } }
+}
--- /dev/null
+/* PR c/102103 - missing warning comparing array address to null
+ { dg-do compile }
+ Verify -Waddress for member arrays of structs and notes.
+ { dg-options "-Wall" } */
+
+#if __cplusplus < 201103L
+# define nullptr __null
+#endif
+
+void T (bool);
+
+struct A
+{
+ int n;
+ int ia[]; // { dg-message "'A::ia' declared here" }
+};
+
+struct B
+{
+ A a[3]; // { dg-message "'B::a' declared here" }
+};
+
+struct C
+{
+ B b[3]; // { dg-message "'C::b' declared here" }
+};
+
+struct D
+{
+ C c[3]; // { dg-message "'D::c' declared here" }
+};
+
+
+void test_waddress_1d ()
+{
+ D d[2]; // { dg-message "'d' declared here" }
+
+ T (d); // { dg-warning "address of 'd'" }
+ T (d == nullptr); // { dg-warning "address of 'd'" }
+ T (&d); // { dg-warning "address of 'd'" }
+ T (d->c); // { dg-warning "address of 'D::c'" }
+ T (d->c != nullptr); // { dg-warning "address of 'D::c'" }
+ T (d->c->b); // { dg-warning "address of 'C::b'" }
+ T (d->c[1].b->a); // { dg-warning "address of 'B::a'" }
+ T (d->c->b[2].a->ia); // { dg-warning "address of 'A::ia'" }
+
+ if (d->c->b[2].a[1].ia) // { dg-warning "address of 'A::ia'" }
+ T (0);
+
+ if (bool b = d->c->b[1].a) // { dg-warning "address of 'B::a'" }
+ T (b);
+
+ /* The following is represented as a declaration of P followed
+ by an if statement and so it isn't diagnosed. It's not clear
+ that it should be since the pointer is then used.
+ void *p = d->c->b[2].a;
+ if (p) ...
+ */
+ if (void *p = d->c->b[2].a) // { dg-warning "address of 'A::ia'" "" { xfail *-*-* } }
+ T (p);
+}
+
+
+void test_waddress_2d (int i)
+{
+ D d[2][3]; // { dg-message "'d' declared here" }
+
+ T (d); // { dg-warning "address of 'd'" }
+ T (d == nullptr); // { dg-warning "address of 'd'" }
+ T (&d); // { dg-warning "address of 'd'" }
+ T (*d); // { dg-warning "address of 'd'" }
+ T (d[1] != nullptr); // { dg-warning "address of 'd'" }
+ T (&d[1]->c); // { dg-warning "address of 'D::c'" }
+ T (d[1]->c); // { dg-warning "address of 'D::c'" }
+ T (d[1]->c == nullptr); // { dg-warning "address of 'D::c'" }
+ T (d[i]->c[1].b); // { dg-warning "address of 'C::b'" }
+ T ((*(d + i))->c->b->a); // { dg-warning "address of 'B::a'" }
+ T (d[1][2].c->b->a->ia); // { dg-warning "address of 'A::ia'" }
+}
return_addr_label_as_intref (void)
{
label:
- if ((const intptr_t*)&&label == 0)
+ if ((const intptr_t)&&label == 0)
__builtin_exit (1);
return *(const intptr_t*)&&label; // { dg-warning "\\\[-Wreturn-local-addr]" } */
return_addr_local_as_intref (void)
{
int a[1];
- if ((const intptr_t*)a == 0)
+ if ((const intptr_t)a == 0)
__builtin_exit (1);
return (const intptr_t&)a; // { dg-warning "\\\[-Wreturn-local-addr]" } */
template <int> bool f() {
void (S::*mp)();
- return &S::m == mp; // no warning emitted here (no instantiation)
+ /* The expression below isn't type-dependent so also verify
+ it's diagnosed even though the template isn't instantiated. */
+ return &S::m == mp; // { dg-warning "\\\[-Waddress" }
}
--- /dev/null
+/* PR c/102103 - missing warning comparing array address to null
+ { dg-do compile }
+ { dg-options "-Wall" } */
+
+typedef _Complex float Cflt;
+
+extern Cflt cf, cfa[], cfa2[][2];
+
+Cflt *pcf (void);
+
+void T (int);
+
+void test_complex (Cflt *p, int i)
+{
+ T (&__real__ cf == 0); // { dg-warning "address of '__real__ cf'" }
+ T (&__imag__ cf == 0); // { dg-warning "address of '__imag__ cf'" }
+
+ T (0 != &__real__ cf); // { dg-warning "-Waddress" }
+ T (0 != &__imag__ cf); // { dg-warning "-Waddress" }
+
+ T (&__real__ cfa[0] == 0); // { dg-warning "-Waddress" }
+ T (&__imag__ cfa[1] == 0); // { dg-warning "-Waddress" }
+
+ T (0 != &__real__ cfa2[i][i]); // { dg-warning "-Waddress" }
+ T (0 != &__imag__ cfa2[i][i]); // { dg-warning "-Waddress" }
+
+ T (0 == &__real__ *p); // { dg-warning "-Waddress" }
+ T (0 == &__imag__ *p); // { dg-warning "-Waddress" }
+
+ T (0 == &__real__ p[i]); // { dg-warning "-Waddress" }
+ T (0 == &__imag__ p[i]); // { dg-warning "-Waddress" }
+
+ T (&__real__ *pcf () == 0); // { dg-warning "-Waddress" }
+ T (0 != &__imag__ *pcf ()); // { dg-warning "-Waddress" }
+}
foo(void)
{
char a[1];
- return a == 0;
+ return a == 0; // { dg-warning "-Waddress" }
}
projects / thirdparty / gcc.git / commitdiff
