static tree
handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
tree ARG_UNUSED (args), int ARG_UNUSED (flags),
bool * ARG_UNUSED (no_add_attrs))
{
/* Ensure we have a function type. */
gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE);
/* Ensure we have a variadic function. */
gcc_assert (!prototype_p (*node) || stdarg_p (*node));
return NULL_TREE;
}
static tree
handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
tree args, int ARG_UNUSED (flags),
bool * ARG_UNUSED (no_add_attrs))
{
tree type = *node;
/* If no arguments are specified, all pointer arguments should be
non-null. Verify a full prototype is given so that the arguments
will have the correct types when we actually check them later.
Avoid diagnosing type-generic built-ins since those have no
prototype. */
if (!args)
{
gcc_assert (prototype_p (type)
|| !TYPE_ATTRIBUTES (type)
|| lookup_attribute ("type generic", TYPE_ATTRIBUTES (type)));
return NULL_TREE;
}
/* Argument list specified. Verify that each argument number references
a pointer argument. */
for (; args; args = TREE_CHAIN (args))
{
tree argument;
unsigned HOST_WIDE_INT arg_num = 0, ck_num;
if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
gcc_unreachable ();
argument = TYPE_ARG_TYPES (type);
if (argument)
{
for (ck_num = 1; ; ck_num++)
{
if (!argument || ck_num == arg_num)
break;
argument = TREE_CHAIN (argument);
}
gcc_assert (argument
&& TREE_CODE (TREE_VALUE (argument)) == POINTER_TYPE);
}
}
return NULL_TREE;
}
bool
useless_type_conversion_p (tree outer_type, tree inner_type)
{
/* Do the following before stripping toplevel qualifiers. */
if (POINTER_TYPE_P (inner_type)
&& POINTER_TYPE_P (outer_type))
{
/* Do not lose casts between pointers to different address spaces. */
if (TYPE_ADDR_SPACE (TREE_TYPE (outer_type))
!= TYPE_ADDR_SPACE (TREE_TYPE (inner_type)))
return false;
/* Do not lose casts to function pointer types. */
if ((TREE_CODE (TREE_TYPE (outer_type)) == FUNCTION_TYPE
|| TREE_CODE (TREE_TYPE (outer_type)) == METHOD_TYPE)
&& !(TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE
|| TREE_CODE (TREE_TYPE (inner_type)) == METHOD_TYPE))
return false;
}
/* From now on qualifiers on value types do not matter. */
inner_type = TYPE_MAIN_VARIANT (inner_type);
outer_type = TYPE_MAIN_VARIANT (outer_type);
if (inner_type == outer_type)
return true;
/* Changes in machine mode are never useless conversions because the RTL
middle-end expects explicit conversions between modes. */
if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type))
return false;
/* If both the inner and outer types are integral types, then the
conversion is not necessary if they have the same mode and
signedness and precision, and both or neither are boolean. */
if (INTEGRAL_TYPE_P (inner_type)
&& INTEGRAL_TYPE_P (outer_type))
{
/* Preserve changes in signedness or precision. */
if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
|| TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
return false;
/* Preserve conversions to/from BOOLEAN_TYPE if types are not
of precision one. */
if (((TREE_CODE (inner_type) == BOOLEAN_TYPE)
!= (TREE_CODE (outer_type) == BOOLEAN_TYPE))
&& TYPE_PRECISION (outer_type) != 1)
return false;
/* We don't need to preserve changes in the types minimum or
maximum value in general as these do not generate code
unless the types precisions are different. */
return true;
}
/* Scalar floating point types with the same mode are compatible. */
else if (SCALAR_FLOAT_TYPE_P (inner_type)
&& SCALAR_FLOAT_TYPE_P (outer_type))
return true;
/* Fixed point types with the same mode are compatible. */
else if (FIXED_POINT_TYPE_P (inner_type)
&& FIXED_POINT_TYPE_P (outer_type))
return true;
/* We need to take special care recursing to pointed-to types. */
else if (POINTER_TYPE_P (inner_type)
&& POINTER_TYPE_P (outer_type))
{
/* We do not care for const qualification of the pointed-to types
as const qualification has no semantic value to the middle-end. */
/* Otherwise pointers/references are equivalent. */
return true;
}
/* Recurse for complex types. */
else if (TREE_CODE (inner_type) == COMPLEX_TYPE
&& TREE_CODE (outer_type) == COMPLEX_TYPE)
return useless_type_conversion_p (TREE_TYPE (outer_type),
TREE_TYPE (inner_type));
/* Recurse for vector types with the same number of subparts. */
else if (TREE_CODE (inner_type) == VECTOR_TYPE
&& TREE_CODE (outer_type) == VECTOR_TYPE
&& TYPE_PRECISION (inner_type) == TYPE_PRECISION (outer_type))
return useless_type_conversion_p (TREE_TYPE (outer_type),
TREE_TYPE (inner_type));
else if (TREE_CODE (inner_type) == ARRAY_TYPE
&& TREE_CODE (outer_type) == ARRAY_TYPE)
{
/* Preserve various attributes. */
if (TYPE_REVERSE_STORAGE_ORDER (inner_type)
!= TYPE_REVERSE_STORAGE_ORDER (outer_type))
return false;
if (TYPE_STRING_FLAG (inner_type) != TYPE_STRING_FLAG (outer_type))
return false;
/* Conversions from array types with unknown extent to
array types with known extent are not useless. */
if (!TYPE_DOMAIN (inner_type) && TYPE_DOMAIN (outer_type))
return false;
/* Nor are conversions from array types with non-constant size to
array types with constant size or to different size. */
if (TYPE_SIZE (outer_type)
&& TREE_CODE (TYPE_SIZE (outer_type)) == INTEGER_CST
&& (!TYPE_SIZE (inner_type)
|| TREE_CODE (TYPE_SIZE (inner_type)) != INTEGER_CST
|| !tree_int_cst_equal (TYPE_SIZE (outer_type),
TYPE_SIZE (inner_type))))
return false;
/* Check conversions between arrays with partially known extents.
If the array min/max values are constant they have to match.
Otherwise allow conversions to unknown and variable extents.
In particular this declares conversions that may change the
mode to BLKmode as useless. */
if (TYPE_DOMAIN (inner_type)
&& TYPE_DOMAIN (outer_type)
&& TYPE_DOMAIN (inner_type) != TYPE_DOMAIN (outer_type))
{
tree inner_min = TYPE_MIN_VALUE (TYPE_DOMAIN (inner_type));
tree outer_min = TYPE_MIN_VALUE (TYPE_DOMAIN (outer_type));
tree inner_max = TYPE_MAX_VALUE (TYPE_DOMAIN (inner_type));
tree outer_max = TYPE_MAX_VALUE (TYPE_DOMAIN (outer_type));
/* After gimplification a variable min/max value carries no
additional information compared to a NULL value. All that
matters has been lowered to be part of the IL. */
if (inner_min && TREE_CODE (inner_min) != INTEGER_CST)
inner_min = NULL_TREE;
if (outer_min && TREE_CODE (outer_min) != INTEGER_CST)
outer_min = NULL_TREE;
if (inner_max && TREE_CODE (inner_max) != INTEGER_CST)
inner_max = NULL_TREE;
if (outer_max && TREE_CODE (outer_max) != INTEGER_CST)
outer_max = NULL_TREE;
/* Conversions NULL / variable <- cst are useless, but not
the other way around. */
if (outer_min
&& (!inner_min
|| !tree_int_cst_equal (inner_min, outer_min)))
return false;
if (outer_max
&& (!inner_max
|| !tree_int_cst_equal (inner_max, outer_max)))
return false;
}
/* Recurse on the element check. */
return useless_type_conversion_p (TREE_TYPE (outer_type),
TREE_TYPE (inner_type));
}
else if ((TREE_CODE (inner_type) == FUNCTION_TYPE
|| TREE_CODE (inner_type) == METHOD_TYPE)
&& TREE_CODE (inner_type) == TREE_CODE (outer_type))
{
tree outer_parm, inner_parm;
/* If the return types are not compatible bail out. */
if (!useless_type_conversion_p (TREE_TYPE (outer_type),
TREE_TYPE (inner_type)))
return false;
/* Method types should belong to a compatible base class. */
if (TREE_CODE (inner_type) == METHOD_TYPE
&& !useless_type_conversion_p (TYPE_METHOD_BASETYPE (outer_type),
TYPE_METHOD_BASETYPE (inner_type)))
return false;
/* A conversion to an unprototyped argument list is ok. */
if (!prototype_p (outer_type))
return true;
/* If the unqualified argument types are compatible the conversion
is useless. */
if (TYPE_ARG_TYPES (outer_type) == TYPE_ARG_TYPES (inner_type))
return true;
for (outer_parm = TYPE_ARG_TYPES (outer_type),
inner_parm = TYPE_ARG_TYPES (inner_type);
outer_parm && inner_parm;
outer_parm = TREE_CHAIN (outer_parm),
inner_parm = TREE_CHAIN (inner_parm))
if (!useless_type_conversion_p
(TYPE_MAIN_VARIANT (TREE_VALUE (outer_parm)),
TYPE_MAIN_VARIANT (TREE_VALUE (inner_parm))))
return false;
/* If there is a mismatch in the number of arguments the functions
are not compatible. */
if (outer_parm || inner_parm)
return false;
/* Defer to the target if necessary. */
if (TYPE_ATTRIBUTES (inner_type) || TYPE_ATTRIBUTES (outer_type))
return comp_type_attributes (outer_type, inner_type) != 0;
return true;
}
/* For aggregates we rely on TYPE_CANONICAL exclusively and require
explicit conversions for types involving to be structurally
compared types. */
else if (AGGREGATE_TYPE_P (inner_type)
&& TREE_CODE (inner_type) == TREE_CODE (outer_type))
return TYPE_CANONICAL (inner_type)
&& TYPE_CANONICAL (inner_type) == TYPE_CANONICAL (outer_type);
else if (TREE_CODE (inner_type) == OFFSET_TYPE
&& TREE_CODE (outer_type) == OFFSET_TYPE)
return useless_type_conversion_p (TREE_TYPE (outer_type),
TREE_TYPE (inner_type))
&& useless_type_conversion_p
(TYPE_OFFSET_BASETYPE (outer_type),
TYPE_OFFSET_BASETYPE (inner_type));
return false;
}
static int
warn_type_compatibility_p (tree prevailing_type, tree type,
bool common_or_extern)
{
int lev = 0;
bool odr_p = odr_or_derived_type_p (prevailing_type)
&& odr_or_derived_type_p (type);
if (prevailing_type == type)
return 0;
/* C++ provide a robust way to check for type compatibility via the ODR
rule. */
if (odr_p && !odr_types_equivalent_p (prevailing_type, type))
lev |= 2;
/* Function types needs special care, because types_compatible_p never
thinks prototype is compatible to non-prototype. */
if (TREE_CODE (type) == FUNCTION_TYPE || TREE_CODE (type) == METHOD_TYPE)
{
if (TREE_CODE (type) != TREE_CODE (prevailing_type))
lev |= 1;
lev |= warn_type_compatibility_p (TREE_TYPE (prevailing_type),
TREE_TYPE (type), false);
if (TREE_CODE (type) == METHOD_TYPE
&& TREE_CODE (prevailing_type) == METHOD_TYPE)
lev |= warn_type_compatibility_p (TYPE_METHOD_BASETYPE (prevailing_type),
TYPE_METHOD_BASETYPE (type), false);
if (prototype_p (prevailing_type) && prototype_p (type)
&& TYPE_ARG_TYPES (prevailing_type) != TYPE_ARG_TYPES (type))
{
tree parm1, parm2;
for (parm1 = TYPE_ARG_TYPES (prevailing_type),
parm2 = TYPE_ARG_TYPES (type);
parm1 && parm2;
parm1 = TREE_CHAIN (parm1),
parm2 = TREE_CHAIN (parm2))
lev |= warn_type_compatibility_p (TREE_VALUE (parm1),
TREE_VALUE (parm2), false);
if (parm1 || parm2)
lev |= odr_p ? 3 : 1;
}
if (comp_type_attributes (prevailing_type, type) == 0)
lev |= 1;
return lev;
}
/* Get complete type. */
prevailing_type = TYPE_MAIN_VARIANT (prevailing_type);
type = TYPE_MAIN_VARIANT (type);
/* We can not use types_compatible_p because we permit some changes
across types. For example unsigned size_t and "signed size_t" may be
compatible when merging C and Fortran types. */
if (COMPLETE_TYPE_P (prevailing_type)
&& COMPLETE_TYPE_P (type)
/* While global declarations are never variadic, we can recurse here
for function parameter types. */
&& TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
&& TREE_CODE (TYPE_SIZE (prevailing_type)) == INTEGER_CST
&& !tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (prevailing_type)))
{
/* As a special case do not warn about merging
int a[];
and
int a[]={1,2,3};
here the first declaration is COMMON or EXTERN
and sizeof(a) == sizeof (int). */
if (!common_or_extern
|| TREE_CODE (type) != ARRAY_TYPE
|| TYPE_SIZE (type) != TYPE_SIZE (TREE_TYPE (type)))
lev |= 1;
}
/* Verify TBAA compatibility. Take care of alias set 0 and the fact that
we make ptr_type_node to TBAA compatible with every other type. */
if (type_with_alias_set_p (type) && type_with_alias_set_p (prevailing_type))
{
alias_set_type set1 = get_alias_set (type);
alias_set_type set2 = get_alias_set (prevailing_type);
if (set1 && set2 && set1 != set2
&& (!POINTER_TYPE_P (type) || !POINTER_TYPE_P (prevailing_type)
|| (set1 != TYPE_ALIAS_SET (ptr_type_node)
&& set2 != TYPE_ALIAS_SET (ptr_type_node))))
lev |= 5;
}
return lev;
}
static const char *
gen_formal_list_for_type (tree fntype, formals_style style)
{
const char *formal_list = "";
tree formal_type;
if (style != ansi)
return "()";
formal_type = TYPE_ARG_TYPES (fntype);
while (formal_type && TREE_VALUE (formal_type) != void_type_node)
{
const char *this_type;
if (*formal_list)
formal_list = concat (formal_list, ", ", NULL);
this_type = gen_type ("", TREE_VALUE (formal_type), ansi);
formal_list
= ((strlen (this_type))
? concat (formal_list, affix_data_type (this_type), NULL)
: concat (formal_list, data_type, NULL));
formal_type = TREE_CHAIN (formal_type);
}
/* If we got to here, then we are trying to generate an ANSI style formal
parameters list.
New style prototyped ANSI formal parameter lists should in theory always
contain some stuff between the opening and closing parens, even if it is
only "void".
The brutal truth though is that there is lots of old K&R code out there
which contains declarations of "pointer-to-function" parameters and
these almost never have fully specified formal parameter lists associated
with them. That is, the pointer-to-function parameters are declared
with just empty parameter lists.
In cases such as these, protoize should really insert *something* into
the vacant parameter lists, but what? It has no basis on which to insert
anything in particular.
Here, we make life easy for protoize by trying to distinguish between
K&R empty parameter lists and new-style prototyped parameter lists
that actually contain "void". In the latter case we (obviously) want
to output the "void" verbatim, and that what we do. In the former case,
we do our best to give protoize something nice to insert.
This "something nice" should be something that is still valid (when
re-compiled) but something that can clearly indicate to the user that
more typing information (for the parameter list) should be added (by
hand) at some convenient moment.
The string chosen here is a comment with question marks in it. */
if (!*formal_list)
{
if (prototype_p (fntype))
/* assert (TREE_VALUE (TYPE_ARG_TYPES (fntype)) == void_type_node); */
formal_list = "void";
else
formal_list = "/* ??? */";
}
else
{
/* If there were at least some parameters, and if the formals-types-list
petered out to a NULL (i.e. without being terminated by a
void_type_node) then we need to tack on an ellipsis. */
if (!formal_type)
formal_list = concat (formal_list, ", ...", NULL);
}
return concat (" (", formal_list, ")", NULL);
}
