/* Functions dealing with attribute handling, used by most front ends.
- Copyright (C) 1992-2015 Free Software Foundation, Inc.
+ Copyright (C) 1992-2020 Free Software Foundation, Inc.
This file is part of GCC.
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
+#define INCLUDE_STRING
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "stringpool.h"
#include "diagnostic-core.h"
#include "attribs.h"
+#include "fold-const.h"
#include "stor-layout.h"
#include "langhooks.h"
#include "plugin.h"
+#include "selftest.h"
+#include "hash-set.h"
+#include "diagnostic.h"
+#include "pretty-print.h"
+#include "tree-pretty-print.h"
+#include "intl.h"
/* Table of the tables of attributes (common, language, format, machine)
searched. */
static const struct attribute_spec empty_attribute_table[] =
{
- { NULL, 0, 0, false, false, false, NULL, false }
+ { NULL, 0, 0, false, false, false, false, NULL, NULL }
};
/* Return base name of the attribute. Ie '__attr__' is turned into 'attr'.
namespace. The function returns the namespace into which the
attributes have been registered. */
-scoped_attributes*
-register_scoped_attributes (const struct attribute_spec * attributes,
- const char* ns)
+scoped_attributes *
+register_scoped_attributes (const struct attribute_spec *attributes,
+ const char *ns)
{
scoped_attributes *result = NULL;
/* We don't have any namespace NS yet. Create one. */
scoped_attributes sa;
- if (!attributes_table.is_empty ())
+ if (attributes_table.is_empty ())
attributes_table.create (64);
memset (&sa, 0, sizeof (sa));
Please read the comments of cxx11_attribute_p to understand the
format of attributes. */
-static tree
+tree
get_attribute_namespace (const_tree attr)
{
if (cxx11_attribute_p (attr))
return get_identifier ("gnu");
}
+/* Check LAST_DECL and NODE of the same symbol for attributes that are
+ recorded in SPEC to be mutually exclusive with ATTRNAME, diagnose
+ them, and return true if any have been found. NODE can be a DECL
+ or a TYPE. */
+
+static bool
+diag_attr_exclusions (tree last_decl, tree node, tree attrname,
+ const attribute_spec *spec)
+{
+ const attribute_spec::exclusions *excl = spec->exclude;
+
+ tree_code code = TREE_CODE (node);
+
+ if ((code == FUNCTION_DECL && !excl->function
+ && (!excl->type || !spec->affects_type_identity))
+ || (code == VAR_DECL && !excl->variable
+ && (!excl->type || !spec->affects_type_identity))
+ || (((code == TYPE_DECL || RECORD_OR_UNION_TYPE_P (node)) && !excl->type)))
+ return false;
+
+ /* True if an attribute that's mutually exclusive with ATTRNAME
+ has been found. */
+ bool found = false;
+
+ if (last_decl && last_decl != node && TREE_TYPE (last_decl) != node)
+ {
+ /* Check both the last DECL and its type for conflicts with
+ the attribute being added to the current decl or type. */
+ found |= diag_attr_exclusions (last_decl, last_decl, attrname, spec);
+ tree decl_type = TREE_TYPE (last_decl);
+ found |= diag_attr_exclusions (last_decl, decl_type, attrname, spec);
+ }
+
+ /* NODE is either the current DECL to which the attribute is being
+ applied or its TYPE. For the former, consider the attributes on
+ both the DECL and its type. */
+ tree attrs[2];
+
+ if (DECL_P (node))
+ {
+ attrs[0] = DECL_ATTRIBUTES (node);
+ attrs[1] = TYPE_ATTRIBUTES (TREE_TYPE (node));
+ }
+ else
+ {
+ attrs[0] = TYPE_ATTRIBUTES (node);
+ attrs[1] = NULL_TREE;
+ }
+
+ /* Iterate over the mutually exclusive attribute names and verify
+ that the symbol doesn't contain it. */
+ for (unsigned i = 0; i != sizeof attrs / sizeof *attrs; ++i)
+ {
+ if (!attrs[i])
+ continue;
+
+ for ( ; excl->name; ++excl)
+ {
+ /* Avoid checking the attribute against itself. */
+ if (is_attribute_p (excl->name, attrname))
+ continue;
+
+ if (!lookup_attribute (excl->name, attrs[i]))
+ continue;
+
+ /* An exclusion may apply either to a function declaration,
+ type declaration, or a field/variable declaration, or
+ any subset of the three. */
+ if (TREE_CODE (node) == FUNCTION_DECL
+ && !excl->function)
+ continue;
+
+ if (TREE_CODE (node) == TYPE_DECL
+ && !excl->type)
+ continue;
+
+ if ((TREE_CODE (node) == FIELD_DECL
+ || TREE_CODE (node) == VAR_DECL)
+ && !excl->variable)
+ continue;
+
+ found = true;
+
+ /* Print a note? */
+ bool note = last_decl != NULL_TREE;
+ auto_diagnostic_group d;
+ if (TREE_CODE (node) == FUNCTION_DECL
+ && fndecl_built_in_p (node))
+ note &= warning (OPT_Wattributes,
+ "ignoring attribute %qE in declaration of "
+ "a built-in function %qD because it conflicts "
+ "with attribute %qs",
+ attrname, node, excl->name);
+ else
+ note &= warning (OPT_Wattributes,
+ "ignoring attribute %qE because "
+ "it conflicts with attribute %qs",
+ attrname, excl->name);
+
+ if (note)
+ inform (DECL_SOURCE_LOCATION (last_decl),
+ "previous declaration here");
+ }
+ }
+
+ return found;
+}
/* Process the attributes listed in ATTRIBUTES and install them in *NODE,
which is either a DECL (including a TYPE_DECL) or a TYPE. If a DECL,
a decl attribute to the declaration rather than to its type). */
tree
-decl_attributes (tree *node, tree attributes, int flags)
+decl_attributes (tree *node, tree attributes, int flags,
+ tree last_decl /* = NULL_TREE */)
{
- tree a;
tree returned_attrs = NULL_TREE;
if (TREE_TYPE (*node) == error_mark_node || attributes == error_mark_node)
those targets that support it. */
if (TREE_CODE (*node) == FUNCTION_DECL
&& attributes
- && lookup_attribute_spec (get_identifier ("naked"))
- && lookup_attribute ("naked", attributes) != NULL)
+ && lookup_attribute ("naked", attributes) != NULL
+ && lookup_attribute_spec (get_identifier ("naked")))
+ {
+ if (lookup_attribute ("noinline", attributes) == NULL)
+ attributes = tree_cons (get_identifier ("noinline"), NULL, attributes);
+
+ if (lookup_attribute ("noclone", attributes) == NULL)
+ attributes = tree_cons (get_identifier ("noclone"), NULL, attributes);
+ }
+
+ /* A "noipa" function attribute implies "noinline", "noclone" and "no_icf"
+ for those targets that support it. */
+ if (TREE_CODE (*node) == FUNCTION_DECL
+ && attributes
+ && lookup_attribute ("noipa", attributes) != NULL
+ && lookup_attribute_spec (get_identifier ("noipa")))
{
if (lookup_attribute ("noinline", attributes) == NULL)
attributes = tree_cons (get_identifier ("noinline"), NULL, attributes);
if (lookup_attribute ("noclone", attributes) == NULL)
attributes = tree_cons (get_identifier ("noclone"), NULL, attributes);
+
+ if (lookup_attribute ("no_icf", attributes) == NULL)
+ attributes = tree_cons (get_identifier ("no_icf"), NULL, attributes);
}
targetm.insert_attributes (*node, &attributes);
- for (a = attributes; a; a = TREE_CHAIN (a))
+ /* Note that attributes on the same declaration are not necessarily
+ in the same order as in the source. */
+ for (tree attr = attributes; attr; attr = TREE_CHAIN (attr))
{
- tree ns = get_attribute_namespace (a);
- tree name = get_attribute_name (a);
- tree args = TREE_VALUE (a);
+ tree ns = get_attribute_namespace (attr);
+ tree name = get_attribute_name (attr);
+ tree args = TREE_VALUE (attr);
tree *anode = node;
- const struct attribute_spec *spec =
- lookup_scoped_attribute_spec (ns, name);
- bool no_add_attrs = 0;
+ const struct attribute_spec *spec
+ = lookup_scoped_attribute_spec (ns, name);
int fn_ptr_quals = 0;
tree fn_ptr_tmp = NULL_TREE;
+ const bool cxx11_attr_p = cxx11_attribute_p (attr);
if (spec == NULL)
{
if (!(flags & (int) ATTR_FLAG_BUILT_IN))
{
- if (ns == NULL_TREE || !cxx11_attribute_p (a))
+ if (ns == NULL_TREE || !cxx11_attr_p)
warning (OPT_Wattributes, "%qE attribute directive ignored",
name);
else
}
continue;
}
- else if (list_length (args) < spec->min_length
- || (spec->max_length >= 0
- && list_length (args) > spec->max_length))
+ else
{
- error ("wrong number of arguments specified for %qE attribute",
- name);
- continue;
+ int nargs = list_length (args);
+ if (nargs < spec->min_length
+ || (spec->max_length >= 0
+ && nargs > spec->max_length))
+ {
+ error ("wrong number of arguments specified for %qE attribute",
+ name);
+ if (spec->max_length < 0)
+ inform (input_location, "expected %i or more, found %i",
+ spec->min_length, nargs);
+ else
+ inform (input_location, "expected between %i and %i, found %i",
+ spec->min_length, spec->max_length, nargs);
+ continue;
+ }
}
gcc_assert (is_attribute_p (spec->name, name));
- if (TYPE_P (*node)
- && cxx11_attribute_p (a)
- && !(flags & ATTR_FLAG_TYPE_IN_PLACE))
- {
- /* This is a c++11 attribute that appertains to a
- type-specifier, outside of the definition of, a class
- type. Ignore it. */
- if (warning (OPT_Wattributes, "attribute ignored"))
- inform (input_location,
- "an attribute that appertains to a type-specifier "
- "is ignored");
- continue;
- }
-
if (spec->decl_required && !DECL_P (*anode))
{
if (flags & ((int) ATTR_FLAG_DECL_NEXT
| (int) ATTR_FLAG_ARRAY_NEXT))
{
/* Pass on this attribute to be tried again. */
- returned_attrs = tree_cons (name, args, returned_attrs);
+ tree attr = tree_cons (name, args, NULL_TREE);
+ returned_attrs = chainon (returned_attrs, attr);
continue;
}
else
else if (flags & (int) ATTR_FLAG_FUNCTION_NEXT)
{
/* Pass on this attribute to be tried again. */
- returned_attrs = tree_cons (name, args, returned_attrs);
+ tree attr = tree_cons (name, args, NULL_TREE);
+ returned_attrs = chainon (returned_attrs, attr);
continue;
}
continue;
}
- if (spec->handler != NULL)
+ bool no_add_attrs = false;
+
+ /* Check for exclusions with other attributes on the current
+ declation as well as the last declaration of the same
+ symbol already processed (if one exists). Detect and
+ reject incompatible attributes. */
+ bool built_in = flags & ATTR_FLAG_BUILT_IN;
+ if (spec->exclude
+ && (flag_checking || !built_in)
+ && !error_operand_p (last_decl))
{
- int cxx11_flag =
- cxx11_attribute_p (a) ? ATTR_FLAG_CXX11 : 0;
+ /* Always check attributes on user-defined functions.
+ Check them on built-ins only when -fchecking is set.
+ Ignore __builtin_unreachable -- it's both const and
+ noreturn. */
+
+ if (!built_in
+ || !DECL_P (*anode)
+ || DECL_BUILT_IN_CLASS (*anode) != BUILT_IN_NORMAL
+ || (DECL_FUNCTION_CODE (*anode) != BUILT_IN_UNREACHABLE
+ && (DECL_FUNCTION_CODE (*anode)
+ != BUILT_IN_UBSAN_HANDLE_BUILTIN_UNREACHABLE)))
+ {
+ bool no_add = diag_attr_exclusions (last_decl, *anode, name, spec);
+ if (!no_add && anode != node)
+ no_add = diag_attr_exclusions (last_decl, *node, name, spec);
+ no_add_attrs |= no_add;
+ }
+ }
+
+ if (no_add_attrs)
+ continue;
- returned_attrs = chainon ((*spec->handler) (anode, name, args,
- flags|cxx11_flag,
- &no_add_attrs),
- returned_attrs);
+ if (spec->handler != NULL)
+ {
+ int cxx11_flag = (cxx11_attr_p ? ATTR_FLAG_CXX11 : 0);
+
+ /* Pass in an array of the current declaration followed
+ by the last pushed/merged declaration if one exists.
+ For calls that modify the type attributes of a DECL
+ and for which *ANODE is *NODE's type, also pass in
+ the DECL as the third element to use in diagnostics.
+ If the handler changes CUR_AND_LAST_DECL[0] replace
+ *ANODE with its value. */
+ tree cur_and_last_decl[3] = { *anode, last_decl };
+ if (anode != node && DECL_P (*node))
+ cur_and_last_decl[2] = *node;
+
+ tree ret = (spec->handler) (cur_and_last_decl, name, args,
+ flags|cxx11_flag, &no_add_attrs);
+
+ *anode = cur_and_last_decl[0];
+ if (ret == error_mark_node)
+ {
+ warning (OPT_Wattributes, "%qE attribute ignored", name);
+ no_add_attrs = true;
+ }
+ else
+ returned_attrs = chainon (ret, returned_attrs);
}
/* Layout the decl in case anything changed. */
if (spec->type_required && DECL_P (*node)
- && (TREE_CODE (*node) == VAR_DECL
+ && (VAR_P (*node)
|| TREE_CODE (*node) == PARM_DECL
|| TREE_CODE (*node) == RESULT_DECL))
relayout_decl (*node);
if (a == NULL_TREE)
{
/* This attribute isn't already in the list. */
+ tree r;
+ /* Preserve the C++11 form. */
+ if (cxx11_attr_p)
+ r = tree_cons (build_tree_list (ns, name), args, old_attrs);
+ else
+ r = tree_cons (name, args, old_attrs);
+
if (DECL_P (*anode))
- DECL_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs);
+ DECL_ATTRIBUTES (*anode) = r;
else if (flags & (int) ATTR_FLAG_TYPE_IN_PLACE)
{
- TYPE_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs);
+ TYPE_ATTRIBUTES (*anode) = r;
/* If this is the main variant, also push the attributes
out to the other variants. */
if (*anode == TYPE_MAIN_VARIANT (*anode))
{
- tree variant;
- for (variant = *anode; variant;
+ for (tree variant = *anode; variant;
variant = TYPE_NEXT_VARIANT (variant))
{
if (TYPE_ATTRIBUTES (variant) == old_attrs)
}
}
else
- *anode = build_type_attribute_variant (*anode,
- tree_cons (name, args,
- old_attrs));
+ *anode = build_type_attribute_variant (*anode, r);
}
}
attr = tree_cons (attr_name, attr_args, chain);
return attr;
}
+
+\f
+/* Common functions used for target clone support. */
+
+/* Comparator function to be used in qsort routine to sort attribute
+ specification strings to "target". */
+
+static int
+attr_strcmp (const void *v1, const void *v2)
+{
+ const char *c1 = *(char *const*)v1;
+ const char *c2 = *(char *const*)v2;
+ return strcmp (c1, c2);
+}
+
+/* ARGLIST is the argument to target attribute. This function tokenizes
+ the comma separated arguments, sorts them and returns a string which
+ is a unique identifier for the comma separated arguments. It also
+ replaces non-identifier characters "=,-" with "_". */
+
+char *
+sorted_attr_string (tree arglist)
+{
+ tree arg;
+ size_t str_len_sum = 0;
+ char **args = NULL;
+ char *attr_str, *ret_str;
+ char *attr = NULL;
+ unsigned int argnum = 1;
+ unsigned int i;
+
+ for (arg = arglist; arg; arg = TREE_CHAIN (arg))
+ {
+ const char *str = TREE_STRING_POINTER (TREE_VALUE (arg));
+ size_t len = strlen (str);
+ str_len_sum += len + 1;
+ if (arg != arglist)
+ argnum++;
+ for (i = 0; i < strlen (str); i++)
+ if (str[i] == ',')
+ argnum++;
+ }
+
+ attr_str = XNEWVEC (char, str_len_sum);
+ str_len_sum = 0;
+ for (arg = arglist; arg; arg = TREE_CHAIN (arg))
+ {
+ const char *str = TREE_STRING_POINTER (TREE_VALUE (arg));
+ size_t len = strlen (str);
+ memcpy (attr_str + str_len_sum, str, len);
+ attr_str[str_len_sum + len] = TREE_CHAIN (arg) ? ',' : '\0';
+ str_len_sum += len + 1;
+ }
+
+ /* Replace "=,-" with "_". */
+ for (i = 0; i < strlen (attr_str); i++)
+ if (attr_str[i] == '=' || attr_str[i]== '-')
+ attr_str[i] = '_';
+
+ if (argnum == 1)
+ return attr_str;
+
+ args = XNEWVEC (char *, argnum);
+
+ i = 0;
+ attr = strtok (attr_str, ",");
+ while (attr != NULL)
+ {
+ args[i] = attr;
+ i++;
+ attr = strtok (NULL, ",");
+ }
+
+ qsort (args, argnum, sizeof (char *), attr_strcmp);
+
+ ret_str = XNEWVEC (char, str_len_sum);
+ str_len_sum = 0;
+ for (i = 0; i < argnum; i++)
+ {
+ size_t len = strlen (args[i]);
+ memcpy (ret_str + str_len_sum, args[i], len);
+ ret_str[str_len_sum + len] = i < argnum - 1 ? '_' : '\0';
+ str_len_sum += len + 1;
+ }
+
+ XDELETEVEC (args);
+ XDELETEVEC (attr_str);
+ return ret_str;
+}
+
+
+/* This function returns true if FN1 and FN2 are versions of the same function,
+ that is, the target strings of the function decls are different. This assumes
+ that FN1 and FN2 have the same signature. */
+
+bool
+common_function_versions (tree fn1, tree fn2)
+{
+ tree attr1, attr2;
+ char *target1, *target2;
+ bool result;
+
+ if (TREE_CODE (fn1) != FUNCTION_DECL
+ || TREE_CODE (fn2) != FUNCTION_DECL)
+ return false;
+
+ attr1 = lookup_attribute ("target", DECL_ATTRIBUTES (fn1));
+ attr2 = lookup_attribute ("target", DECL_ATTRIBUTES (fn2));
+
+ /* At least one function decl should have the target attribute specified. */
+ if (attr1 == NULL_TREE && attr2 == NULL_TREE)
+ return false;
+
+ /* Diagnose missing target attribute if one of the decls is already
+ multi-versioned. */
+ if (attr1 == NULL_TREE || attr2 == NULL_TREE)
+ {
+ if (DECL_FUNCTION_VERSIONED (fn1) || DECL_FUNCTION_VERSIONED (fn2))
+ {
+ if (attr2 != NULL_TREE)
+ {
+ std::swap (fn1, fn2);
+ attr1 = attr2;
+ }
+ error_at (DECL_SOURCE_LOCATION (fn2),
+ "missing %<target%> attribute for multi-versioned %qD",
+ fn2);
+ inform (DECL_SOURCE_LOCATION (fn1),
+ "previous declaration of %qD", fn1);
+ /* Prevent diagnosing of the same error multiple times. */
+ DECL_ATTRIBUTES (fn2)
+ = tree_cons (get_identifier ("target"),
+ copy_node (TREE_VALUE (attr1)),
+ DECL_ATTRIBUTES (fn2));
+ }
+ return false;
+ }
+
+ target1 = sorted_attr_string (TREE_VALUE (attr1));
+ target2 = sorted_attr_string (TREE_VALUE (attr2));
+
+ /* The sorted target strings must be different for fn1 and fn2
+ to be versions. */
+ if (strcmp (target1, target2) == 0)
+ result = false;
+ else
+ result = true;
+
+ XDELETEVEC (target1);
+ XDELETEVEC (target2);
+
+ return result;
+}
+
+/* Return a new name by appending SUFFIX to the DECL name. If make_unique
+ is true, append the full path name of the source file. */
+
+char *
+make_unique_name (tree decl, const char *suffix, bool make_unique)
+{
+ char *global_var_name;
+ int name_len;
+ const char *name;
+ const char *unique_name = NULL;
+
+ name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
+
+ /* Get a unique name that can be used globally without any chances
+ of collision at link time. */
+ if (make_unique)
+ unique_name = IDENTIFIER_POINTER (get_file_function_name ("\0"));
+
+ name_len = strlen (name) + strlen (suffix) + 2;
+
+ if (make_unique)
+ name_len += strlen (unique_name) + 1;
+ global_var_name = XNEWVEC (char, name_len);
+
+ /* Use '.' to concatenate names as it is demangler friendly. */
+ if (make_unique)
+ snprintf (global_var_name, name_len, "%s.%s.%s", name, unique_name,
+ suffix);
+ else
+ snprintf (global_var_name, name_len, "%s.%s", name, suffix);
+
+ return global_var_name;
+}
+
+/* Make a dispatcher declaration for the multi-versioned function DECL.
+ Calls to DECL function will be replaced with calls to the dispatcher
+ by the front-end. Return the decl created. */
+
+tree
+make_dispatcher_decl (const tree decl)
+{
+ tree func_decl;
+ char *func_name;
+ tree fn_type, func_type;
+
+ func_name = xstrdup (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
+
+ fn_type = TREE_TYPE (decl);
+ func_type = build_function_type (TREE_TYPE (fn_type),
+ TYPE_ARG_TYPES (fn_type));
+
+ func_decl = build_fn_decl (func_name, func_type);
+ XDELETEVEC (func_name);
+ TREE_USED (func_decl) = 1;
+ DECL_CONTEXT (func_decl) = NULL_TREE;
+ DECL_INITIAL (func_decl) = error_mark_node;
+ DECL_ARTIFICIAL (func_decl) = 1;
+ /* Mark this func as external, the resolver will flip it again if
+ it gets generated. */
+ DECL_EXTERNAL (func_decl) = 1;
+ /* This will be of type IFUNCs have to be externally visible. */
+ TREE_PUBLIC (func_decl) = 1;
+
+ return func_decl;
+}
+
+/* Returns true if decl is multi-versioned and DECL is the default function,
+ that is it is not tagged with target specific optimization. */
+
+bool
+is_function_default_version (const tree decl)
+{
+ if (TREE_CODE (decl) != FUNCTION_DECL
+ || !DECL_FUNCTION_VERSIONED (decl))
+ return false;
+ tree attr = lookup_attribute ("target", DECL_ATTRIBUTES (decl));
+ gcc_assert (attr);
+ attr = TREE_VALUE (TREE_VALUE (attr));
+ return (TREE_CODE (attr) == STRING_CST
+ && strcmp (TREE_STRING_POINTER (attr), "default") == 0);
+}
+
+/* Return a declaration like DDECL except that its DECL_ATTRIBUTES
+ is ATTRIBUTE. */
+
+tree
+build_decl_attribute_variant (tree ddecl, tree attribute)
+{
+ DECL_ATTRIBUTES (ddecl) = attribute;
+ return ddecl;
+}
+
+/* Return a type like TTYPE except that its TYPE_ATTRIBUTE
+ is ATTRIBUTE and its qualifiers are QUALS.
+
+ Record such modified types already made so we don't make duplicates. */
+
+tree
+build_type_attribute_qual_variant (tree otype, tree attribute, int quals)
+{
+ tree ttype = otype;
+ if (! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
+ {
+ tree ntype;
+
+ /* Building a distinct copy of a tagged type is inappropriate; it
+ causes breakage in code that expects there to be a one-to-one
+ relationship between a struct and its fields.
+ build_duplicate_type is another solution (as used in
+ handle_transparent_union_attribute), but that doesn't play well
+ with the stronger C++ type identity model. */
+ if (TREE_CODE (ttype) == RECORD_TYPE
+ || TREE_CODE (ttype) == UNION_TYPE
+ || TREE_CODE (ttype) == QUAL_UNION_TYPE
+ || TREE_CODE (ttype) == ENUMERAL_TYPE)
+ {
+ warning (OPT_Wattributes,
+ "ignoring attributes applied to %qT after definition",
+ TYPE_MAIN_VARIANT (ttype));
+ return build_qualified_type (ttype, quals);
+ }
+
+ ttype = build_qualified_type (ttype, TYPE_UNQUALIFIED);
+ if (lang_hooks.types.copy_lang_qualifiers
+ && otype != TYPE_MAIN_VARIANT (otype))
+ ttype = (lang_hooks.types.copy_lang_qualifiers
+ (ttype, TYPE_MAIN_VARIANT (otype)));
+
+ tree dtype = ntype = build_distinct_type_copy (ttype);
+
+ TYPE_ATTRIBUTES (ntype) = attribute;
+
+ hashval_t hash = type_hash_canon_hash (ntype);
+ ntype = type_hash_canon (hash, ntype);
+
+ if (ntype != dtype)
+ /* This variant was already in the hash table, don't mess with
+ TYPE_CANONICAL. */;
+ else if (TYPE_STRUCTURAL_EQUALITY_P (ttype)
+ || !comp_type_attributes (ntype, ttype))
+ /* If the target-dependent attributes make NTYPE different from
+ its canonical type, we will need to use structural equality
+ checks for this type.
+
+ We shouldn't get here for stripping attributes from a type;
+ the no-attribute type might not need structural comparison. But
+ we can if was discarded from type_hash_table. */
+ SET_TYPE_STRUCTURAL_EQUALITY (ntype);
+ else if (TYPE_CANONICAL (ntype) == ntype)
+ TYPE_CANONICAL (ntype) = TYPE_CANONICAL (ttype);
+
+ ttype = build_qualified_type (ntype, quals);
+ if (lang_hooks.types.copy_lang_qualifiers
+ && otype != TYPE_MAIN_VARIANT (otype))
+ ttype = lang_hooks.types.copy_lang_qualifiers (ttype, otype);
+ }
+ else if (TYPE_QUALS (ttype) != quals)
+ ttype = build_qualified_type (ttype, quals);
+
+ return ttype;
+}
+
+/* Compare two identifier nodes representing attributes.
+ Return true if they are the same, false otherwise. */
+
+static bool
+cmp_attrib_identifiers (const_tree attr1, const_tree attr2)
+{
+ /* Make sure we're dealing with IDENTIFIER_NODEs. */
+ gcc_checking_assert (TREE_CODE (attr1) == IDENTIFIER_NODE
+ && TREE_CODE (attr2) == IDENTIFIER_NODE);
+
+ /* Identifiers can be compared directly for equality. */
+ if (attr1 == attr2)
+ return true;
+
+ return cmp_attribs (IDENTIFIER_POINTER (attr1), IDENTIFIER_LENGTH (attr1),
+ IDENTIFIER_POINTER (attr2), IDENTIFIER_LENGTH (attr2));
+}
+
+/* Compare two constructor-element-type constants. Return 1 if the lists
+ are known to be equal; otherwise return 0. */
+
+static bool
+simple_cst_list_equal (const_tree l1, const_tree l2)
+{
+ while (l1 != NULL_TREE && l2 != NULL_TREE)
+ {
+ if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
+ return false;
+
+ l1 = TREE_CHAIN (l1);
+ l2 = TREE_CHAIN (l2);
+ }
+
+ return l1 == l2;
+}
+
+/* Check if "omp declare simd" attribute arguments, CLAUSES1 and CLAUSES2, are
+ the same. */
+
+static bool
+omp_declare_simd_clauses_equal (tree clauses1, tree clauses2)
+{
+ tree cl1, cl2;
+ for (cl1 = clauses1, cl2 = clauses2;
+ cl1 && cl2;
+ cl1 = OMP_CLAUSE_CHAIN (cl1), cl2 = OMP_CLAUSE_CHAIN (cl2))
+ {
+ if (OMP_CLAUSE_CODE (cl1) != OMP_CLAUSE_CODE (cl2))
+ return false;
+ if (OMP_CLAUSE_CODE (cl1) != OMP_CLAUSE_SIMDLEN)
+ {
+ if (simple_cst_equal (OMP_CLAUSE_DECL (cl1),
+ OMP_CLAUSE_DECL (cl2)) != 1)
+ return false;
+ }
+ switch (OMP_CLAUSE_CODE (cl1))
+ {
+ case OMP_CLAUSE_ALIGNED:
+ if (simple_cst_equal (OMP_CLAUSE_ALIGNED_ALIGNMENT (cl1),
+ OMP_CLAUSE_ALIGNED_ALIGNMENT (cl2)) != 1)
+ return false;
+ break;
+ case OMP_CLAUSE_LINEAR:
+ if (simple_cst_equal (OMP_CLAUSE_LINEAR_STEP (cl1),
+ OMP_CLAUSE_LINEAR_STEP (cl2)) != 1)
+ return false;
+ break;
+ case OMP_CLAUSE_SIMDLEN:
+ if (simple_cst_equal (OMP_CLAUSE_SIMDLEN_EXPR (cl1),
+ OMP_CLAUSE_SIMDLEN_EXPR (cl2)) != 1)
+ return false;
+ default:
+ break;
+ }
+ }
+ return true;
+}
+
+
+/* Compare two attributes for their value identity. Return true if the
+ attribute values are known to be equal; otherwise return false. */
+
+bool
+attribute_value_equal (const_tree attr1, const_tree attr2)
+{
+ if (TREE_VALUE (attr1) == TREE_VALUE (attr2))
+ return true;
+
+ if (TREE_VALUE (attr1) != NULL_TREE
+ && TREE_CODE (TREE_VALUE (attr1)) == TREE_LIST
+ && TREE_VALUE (attr2) != NULL_TREE
+ && TREE_CODE (TREE_VALUE (attr2)) == TREE_LIST)
+ {
+ /* Handle attribute format. */
+ if (is_attribute_p ("format", get_attribute_name (attr1)))
+ {
+ attr1 = TREE_VALUE (attr1);
+ attr2 = TREE_VALUE (attr2);
+ /* Compare the archetypes (printf/scanf/strftime/...). */
+ if (!cmp_attrib_identifiers (TREE_VALUE (attr1), TREE_VALUE (attr2)))
+ return false;
+ /* Archetypes are the same. Compare the rest. */
+ return (simple_cst_list_equal (TREE_CHAIN (attr1),
+ TREE_CHAIN (attr2)) == 1);
+ }
+ return (simple_cst_list_equal (TREE_VALUE (attr1),
+ TREE_VALUE (attr2)) == 1);
+ }
+
+ if (TREE_VALUE (attr1)
+ && TREE_CODE (TREE_VALUE (attr1)) == OMP_CLAUSE
+ && TREE_VALUE (attr2)
+ && TREE_CODE (TREE_VALUE (attr2)) == OMP_CLAUSE)
+ return omp_declare_simd_clauses_equal (TREE_VALUE (attr1),
+ TREE_VALUE (attr2));
+
+ return (simple_cst_equal (TREE_VALUE (attr1), TREE_VALUE (attr2)) == 1);
+}
+
+/* Return 0 if the attributes for two types are incompatible, 1 if they
+ are compatible, and 2 if they are nearly compatible (which causes a
+ warning to be generated). */
+int
+comp_type_attributes (const_tree type1, const_tree type2)
+{
+ const_tree a1 = TYPE_ATTRIBUTES (type1);
+ const_tree a2 = TYPE_ATTRIBUTES (type2);
+ const_tree a;
+
+ if (a1 == a2)
+ return 1;
+ for (a = a1; a != NULL_TREE; a = TREE_CHAIN (a))
+ {
+ const struct attribute_spec *as;
+ const_tree attr;
+
+ as = lookup_attribute_spec (get_attribute_name (a));
+ if (!as || as->affects_type_identity == false)
+ continue;
+
+ attr = lookup_attribute (as->name, CONST_CAST_TREE (a2));
+ if (!attr || !attribute_value_equal (a, attr))
+ break;
+ }
+ if (!a)
+ {
+ for (a = a2; a != NULL_TREE; a = TREE_CHAIN (a))
+ {
+ const struct attribute_spec *as;
+
+ as = lookup_attribute_spec (get_attribute_name (a));
+ if (!as || as->affects_type_identity == false)
+ continue;
+
+ if (!lookup_attribute (as->name, CONST_CAST_TREE (a1)))
+ break;
+ /* We don't need to compare trees again, as we did this
+ already in first loop. */
+ }
+ /* All types - affecting identity - are equal, so
+ there is no need to call target hook for comparison. */
+ if (!a)
+ return 1;
+ }
+ if (lookup_attribute ("transaction_safe", CONST_CAST_TREE (a)))
+ return 0;
+ if ((lookup_attribute ("nocf_check", TYPE_ATTRIBUTES (type1)) != NULL)
+ ^ (lookup_attribute ("nocf_check", TYPE_ATTRIBUTES (type2)) != NULL))
+ return 0;
+ /* As some type combinations - like default calling-convention - might
+ be compatible, we have to call the target hook to get the final result. */
+ return targetm.comp_type_attributes (type1, type2);
+}
+
+/* Return a type like TTYPE except that its TYPE_ATTRIBUTE
+ is ATTRIBUTE.
+
+ Record such modified types already made so we don't make duplicates. */
+
+tree
+build_type_attribute_variant (tree ttype, tree attribute)
+{
+ return build_type_attribute_qual_variant (ttype, attribute,
+ TYPE_QUALS (ttype));
+}
+\f
+/* A variant of lookup_attribute() that can be used with an identifier
+ as the first argument, and where the identifier can be either
+ 'text' or '__text__'.
+
+ Given an attribute ATTR_IDENTIFIER, and a list of attributes LIST,
+ return a pointer to the attribute's list element if the attribute
+ is part of the list, or NULL_TREE if not found. If the attribute
+ appears more than once, this only returns the first occurrence; the
+ TREE_CHAIN of the return value should be passed back in if further
+ occurrences are wanted. ATTR_IDENTIFIER must be an identifier but
+ can be in the form 'text' or '__text__'. */
+static tree
+lookup_ident_attribute (tree attr_identifier, tree list)
+{
+ gcc_checking_assert (TREE_CODE (attr_identifier) == IDENTIFIER_NODE);
+
+ while (list)
+ {
+ gcc_checking_assert (TREE_CODE (get_attribute_name (list))
+ == IDENTIFIER_NODE);
+
+ if (cmp_attrib_identifiers (attr_identifier,
+ get_attribute_name (list)))
+ /* Found it. */
+ break;
+ list = TREE_CHAIN (list);
+ }
+
+ return list;
+}
+
+/* Remove any instances of attribute ATTR_NAME in LIST and return the
+ modified list. */
+
+tree
+remove_attribute (const char *attr_name, tree list)
+{
+ tree *p;
+ gcc_checking_assert (attr_name[0] != '_');
+
+ for (p = &list; *p;)
+ {
+ tree l = *p;
+
+ tree attr = get_attribute_name (l);
+ if (is_attribute_p (attr_name, attr))
+ *p = TREE_CHAIN (l);
+ else
+ p = &TREE_CHAIN (l);
+ }
+
+ return list;
+}
+
+/* Return an attribute list that is the union of a1 and a2. */
+
+tree
+merge_attributes (tree a1, tree a2)
+{
+ tree attributes;
+
+ /* Either one unset? Take the set one. */
+
+ if ((attributes = a1) == 0)
+ attributes = a2;
+
+ /* One that completely contains the other? Take it. */
+
+ else if (a2 != 0 && ! attribute_list_contained (a1, a2))
+ {
+ if (attribute_list_contained (a2, a1))
+ attributes = a2;
+ else
+ {
+ /* Pick the longest list, and hang on the other list. */
+
+ if (list_length (a1) < list_length (a2))
+ attributes = a2, a2 = a1;
+
+ for (; a2 != 0; a2 = TREE_CHAIN (a2))
+ {
+ tree a;
+ for (a = lookup_ident_attribute (get_attribute_name (a2),
+ attributes);
+ a != NULL_TREE && !attribute_value_equal (a, a2);
+ a = lookup_ident_attribute (get_attribute_name (a2),
+ TREE_CHAIN (a)))
+ ;
+ if (a == NULL_TREE)
+ {
+ a1 = copy_node (a2);
+ TREE_CHAIN (a1) = attributes;
+ attributes = a1;
+ }
+ }
+ }
+ }
+ return attributes;
+}
+
+/* Given types T1 and T2, merge their attributes and return
+ the result. */
+
+tree
+merge_type_attributes (tree t1, tree t2)
+{
+ return merge_attributes (TYPE_ATTRIBUTES (t1),
+ TYPE_ATTRIBUTES (t2));
+}
+
+/* Given decls OLDDECL and NEWDECL, merge their attributes and return
+ the result. */
+
+tree
+merge_decl_attributes (tree olddecl, tree newdecl)
+{
+ return merge_attributes (DECL_ATTRIBUTES (olddecl),
+ DECL_ATTRIBUTES (newdecl));
+}
+
+/* Duplicate all attributes with name NAME in ATTR list to *ATTRS if
+ they are missing there. */
+
+void
+duplicate_one_attribute (tree *attrs, tree attr, const char *name)
+{
+ attr = lookup_attribute (name, attr);
+ if (!attr)
+ return;
+ tree a = lookup_attribute (name, *attrs);
+ while (attr)
+ {
+ tree a2;
+ for (a2 = a; a2; a2 = lookup_attribute (name, TREE_CHAIN (a2)))
+ if (attribute_value_equal (attr, a2))
+ break;
+ if (!a2)
+ {
+ a2 = copy_node (attr);
+ TREE_CHAIN (a2) = *attrs;
+ *attrs = a2;
+ }
+ attr = lookup_attribute (name, TREE_CHAIN (attr));
+ }
+}
+
+/* Duplicate all attributes from user DECL to the corresponding
+ builtin that should be propagated. */
+
+void
+copy_attributes_to_builtin (tree decl)
+{
+ tree b = builtin_decl_explicit (DECL_FUNCTION_CODE (decl));
+ if (b)
+ duplicate_one_attribute (&DECL_ATTRIBUTES (b),
+ DECL_ATTRIBUTES (decl), "omp declare simd");
+}
+
+#if TARGET_DLLIMPORT_DECL_ATTRIBUTES
+
+/* Specialization of merge_decl_attributes for various Windows targets.
+
+ This handles the following situation:
+
+ __declspec (dllimport) int foo;
+ int foo;
+
+ The second instance of `foo' nullifies the dllimport. */
+
+tree
+merge_dllimport_decl_attributes (tree old, tree new_tree)
+{
+ tree a;
+ int delete_dllimport_p = 1;
+
+ /* What we need to do here is remove from `old' dllimport if it doesn't
+ appear in `new'. dllimport behaves like extern: if a declaration is
+ marked dllimport and a definition appears later, then the object
+ is not dllimport'd. We also remove a `new' dllimport if the old list
+ contains dllexport: dllexport always overrides dllimport, regardless
+ of the order of declaration. */
+ if (!VAR_OR_FUNCTION_DECL_P (new_tree))
+ delete_dllimport_p = 0;
+ else if (DECL_DLLIMPORT_P (new_tree)
+ && lookup_attribute ("dllexport", DECL_ATTRIBUTES (old)))
+ {
+ DECL_DLLIMPORT_P (new_tree) = 0;
+ warning (OPT_Wattributes, "%q+D already declared with dllexport "
+ "attribute: dllimport ignored", new_tree);
+ }
+ else if (DECL_DLLIMPORT_P (old) && !DECL_DLLIMPORT_P (new_tree))
+ {
+ /* Warn about overriding a symbol that has already been used, e.g.:
+ extern int __attribute__ ((dllimport)) foo;
+ int* bar () {return &foo;}
+ int foo;
+ */
+ if (TREE_USED (old))
+ {
+ warning (0, "%q+D redeclared without dllimport attribute "
+ "after being referenced with dll linkage", new_tree);
+ /* If we have used a variable's address with dllimport linkage,
+ keep the old DECL_DLLIMPORT_P flag: the ADDR_EXPR using the
+ decl may already have had TREE_CONSTANT computed.
+ We still remove the attribute so that assembler code refers
+ to '&foo rather than '_imp__foo'. */
+ if (VAR_P (old) && TREE_ADDRESSABLE (old))
+ DECL_DLLIMPORT_P (new_tree) = 1;
+ }
+
+ /* Let an inline definition silently override the external reference,
+ but otherwise warn about attribute inconsistency. */
+ else if (VAR_P (new_tree) || !DECL_DECLARED_INLINE_P (new_tree))
+ warning (OPT_Wattributes, "%q+D redeclared without dllimport "
+ "attribute: previous dllimport ignored", new_tree);
+ }
+ else
+ delete_dllimport_p = 0;
+
+ a = merge_attributes (DECL_ATTRIBUTES (old), DECL_ATTRIBUTES (new_tree));
+
+ if (delete_dllimport_p)
+ a = remove_attribute ("dllimport", a);
+
+ return a;
+}
+
+/* Handle a "dllimport" or "dllexport" attribute; arguments as in
+ struct attribute_spec.handler. */
+
+tree
+handle_dll_attribute (tree * pnode, tree name, tree args, int flags,
+ bool *no_add_attrs)
+{
+ tree node = *pnode;
+ bool is_dllimport;
+
+ /* These attributes may apply to structure and union types being created,
+ but otherwise should pass to the declaration involved. */
+ if (!DECL_P (node))
+ {
+ if (flags & ((int) ATTR_FLAG_DECL_NEXT | (int) ATTR_FLAG_FUNCTION_NEXT
+ | (int) ATTR_FLAG_ARRAY_NEXT))
+ {
+ *no_add_attrs = true;
+ return tree_cons (name, args, NULL_TREE);
+ }
+ if (TREE_CODE (node) == RECORD_TYPE
+ || TREE_CODE (node) == UNION_TYPE)
+ {
+ node = TYPE_NAME (node);
+ if (!node)
+ return NULL_TREE;
+ }
+ else
+ {
+ warning (OPT_Wattributes, "%qE attribute ignored",
+ name);
+ *no_add_attrs = true;
+ return NULL_TREE;
+ }
+ }
+
+ if (!VAR_OR_FUNCTION_DECL_P (node) && TREE_CODE (node) != TYPE_DECL)
+ {
+ *no_add_attrs = true;
+ warning (OPT_Wattributes, "%qE attribute ignored",
+ name);
+ return NULL_TREE;
+ }
+
+ if (TREE_CODE (node) == TYPE_DECL
+ && TREE_CODE (TREE_TYPE (node)) != RECORD_TYPE
+ && TREE_CODE (TREE_TYPE (node)) != UNION_TYPE)
+ {
+ *no_add_attrs = true;
+ warning (OPT_Wattributes, "%qE attribute ignored",
+ name);
+ return NULL_TREE;
+ }
+
+ is_dllimport = is_attribute_p ("dllimport", name);
+
+ /* Report error on dllimport ambiguities seen now before they cause
+ any damage. */
+ if (is_dllimport)
+ {
+ /* Honor any target-specific overrides. */
+ if (!targetm.valid_dllimport_attribute_p (node))
+ *no_add_attrs = true;
+
+ else if (TREE_CODE (node) == FUNCTION_DECL
+ && DECL_DECLARED_INLINE_P (node))
+ {
+ warning (OPT_Wattributes, "inline function %q+D declared as "
+ "dllimport: attribute ignored", node);
+ *no_add_attrs = true;
+ }
+ /* Like MS, treat definition of dllimported variables and
+ non-inlined functions on declaration as syntax errors. */
+ else if (TREE_CODE (node) == FUNCTION_DECL && DECL_INITIAL (node))
+ {
+ error ("function %q+D definition is marked dllimport", node);
+ *no_add_attrs = true;
+ }
+
+ else if (VAR_P (node))
+ {
+ if (DECL_INITIAL (node))
+ {
+ error ("variable %q+D definition is marked dllimport",
+ node);
+ *no_add_attrs = true;
+ }
+
+ /* `extern' needn't be specified with dllimport.
+ Specify `extern' now and hope for the best. Sigh. */
+ DECL_EXTERNAL (node) = 1;
+ /* Also, implicitly give dllimport'd variables declared within
+ a function global scope, unless declared static. */
+ if (current_function_decl != NULL_TREE && !TREE_STATIC (node))
+ TREE_PUBLIC (node) = 1;
+ /* Clear TREE_STATIC because DECL_EXTERNAL is set, unless
+ it is a C++ static data member. */
+ if (DECL_CONTEXT (node) == NULL_TREE
+ || !RECORD_OR_UNION_TYPE_P (DECL_CONTEXT (node)))
+ TREE_STATIC (node) = 0;
+ }
+
+ if (*no_add_attrs == false)
+ DECL_DLLIMPORT_P (node) = 1;
+ }
+ else if (TREE_CODE (node) == FUNCTION_DECL
+ && DECL_DECLARED_INLINE_P (node)
+ && flag_keep_inline_dllexport)
+ /* An exported function, even if inline, must be emitted. */
+ DECL_EXTERNAL (node) = 0;
+
+ /* Report error if symbol is not accessible at global scope. */
+ if (!TREE_PUBLIC (node) && VAR_OR_FUNCTION_DECL_P (node))
+ {
+ error ("external linkage required for symbol %q+D because of "
+ "%qE attribute", node, name);
+ *no_add_attrs = true;
+ }
+
+ /* A dllexport'd entity must have default visibility so that other
+ program units (shared libraries or the main executable) can see
+ it. A dllimport'd entity must have default visibility so that
+ the linker knows that undefined references within this program
+ unit can be resolved by the dynamic linker. */
+ if (!*no_add_attrs)
+ {
+ if (DECL_VISIBILITY_SPECIFIED (node)
+ && DECL_VISIBILITY (node) != VISIBILITY_DEFAULT)
+ error ("%qE implies default visibility, but %qD has already "
+ "been declared with a different visibility",
+ name, node);
+ DECL_VISIBILITY (node) = VISIBILITY_DEFAULT;
+ DECL_VISIBILITY_SPECIFIED (node) = 1;
+ }
+
+ return NULL_TREE;
+}
+
+#endif /* TARGET_DLLIMPORT_DECL_ATTRIBUTES */
+
+/* Given two lists of attributes, return true if list l2 is
+ equivalent to l1. */
+
+int
+attribute_list_equal (const_tree l1, const_tree l2)
+{
+ if (l1 == l2)
+ return 1;
+
+ return attribute_list_contained (l1, l2)
+ && attribute_list_contained (l2, l1);
+}
+
+/* Given two lists of attributes, return true if list L2 is
+ completely contained within L1. */
+/* ??? This would be faster if attribute names were stored in a canonicalized
+ form. Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
+ must be used to show these elements are equivalent (which they are). */
+/* ??? It's not clear that attributes with arguments will always be handled
+ correctly. */
+
+int
+attribute_list_contained (const_tree l1, const_tree l2)
+{
+ const_tree t1, t2;
+
+ /* First check the obvious, maybe the lists are identical. */
+ if (l1 == l2)
+ return 1;
+
+ /* Maybe the lists are similar. */
+ for (t1 = l1, t2 = l2;
+ t1 != 0 && t2 != 0
+ && get_attribute_name (t1) == get_attribute_name (t2)
+ && TREE_VALUE (t1) == TREE_VALUE (t2);
+ t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
+ ;
+
+ /* Maybe the lists are equal. */
+ if (t1 == 0 && t2 == 0)
+ return 1;
+
+ for (; t2 != 0; t2 = TREE_CHAIN (t2))
+ {
+ const_tree attr;
+ /* This CONST_CAST is okay because lookup_attribute does not
+ modify its argument and the return value is assigned to a
+ const_tree. */
+ for (attr = lookup_ident_attribute (get_attribute_name (t2),
+ CONST_CAST_TREE (l1));
+ attr != NULL_TREE && !attribute_value_equal (t2, attr);
+ attr = lookup_ident_attribute (get_attribute_name (t2),
+ TREE_CHAIN (attr)))
+ ;
+
+ if (attr == NULL_TREE)
+ return 0;
+ }
+
+ return 1;
+}
+
+/* The backbone of lookup_attribute(). ATTR_LEN is the string length
+ of ATTR_NAME, and LIST is not NULL_TREE.
+
+ The function is called from lookup_attribute in order to optimize
+ for size. */
+
+tree
+private_lookup_attribute (const char *attr_name, size_t attr_len, tree list)
+{
+ while (list)
+ {
+ tree attr = get_attribute_name (list);
+ size_t ident_len = IDENTIFIER_LENGTH (attr);
+ if (cmp_attribs (attr_name, attr_len, IDENTIFIER_POINTER (attr),
+ ident_len))
+ break;
+ list = TREE_CHAIN (list);
+ }
+
+ return list;
+}
+
+/* Return true if the function decl or type NODE has been declared
+ with attribute ANAME among attributes ATTRS. */
+
+static bool
+has_attribute (tree node, tree attrs, const char *aname)
+{
+ if (!strcmp (aname, "const"))
+ {
+ if (DECL_P (node) && TREE_READONLY (node))
+ return true;
+ }
+ else if (!strcmp (aname, "malloc"))
+ {
+ if (DECL_P (node) && DECL_IS_MALLOC (node))
+ return true;
+ }
+ else if (!strcmp (aname, "noreturn"))
+ {
+ if (DECL_P (node) && TREE_THIS_VOLATILE (node))
+ return true;
+ }
+ else if (!strcmp (aname, "nothrow"))
+ {
+ if (TREE_NOTHROW (node))
+ return true;
+ }
+ else if (!strcmp (aname, "pure"))
+ {
+ if (DECL_P (node) && DECL_PURE_P (node))
+ return true;
+ }
+
+ return lookup_attribute (aname, attrs);
+}
+
+/* Return the number of mismatched function or type attributes between
+ the "template" function declaration TMPL and DECL. The word "template"
+ doesn't necessarily refer to a C++ template but rather a declaration
+ whose attributes should be matched by those on DECL. For a non-zero
+ return value set *ATTRSTR to a string representation of the list of
+ mismatched attributes with quoted names.
+ ATTRLIST is a list of additional attributes that SPEC should be
+ taken to ultimately be declared with. */
+
+unsigned
+decls_mismatched_attributes (tree tmpl, tree decl, tree attrlist,
+ const char* const blacklist[],
+ pretty_printer *attrstr)
+{
+ if (TREE_CODE (tmpl) != FUNCTION_DECL)
+ return 0;
+
+ /* Avoid warning if either declaration or its type is deprecated. */
+ if (TREE_DEPRECATED (tmpl)
+ || TREE_DEPRECATED (decl))
+ return 0;
+
+ const tree tmpls[] = { tmpl, TREE_TYPE (tmpl) };
+ const tree decls[] = { decl, TREE_TYPE (decl) };
+
+ if (TREE_DEPRECATED (tmpls[1])
+ || TREE_DEPRECATED (decls[1])
+ || TREE_DEPRECATED (TREE_TYPE (tmpls[1]))
+ || TREE_DEPRECATED (TREE_TYPE (decls[1])))
+ return 0;
+
+ tree tmpl_attrs[] = { DECL_ATTRIBUTES (tmpl), TYPE_ATTRIBUTES (tmpls[1]) };
+ tree decl_attrs[] = { DECL_ATTRIBUTES (decl), TYPE_ATTRIBUTES (decls[1]) };
+
+ if (!decl_attrs[0])
+ decl_attrs[0] = attrlist;
+ else if (!decl_attrs[1])
+ decl_attrs[1] = attrlist;
+
+ /* Avoid warning if the template has no attributes. */
+ if (!tmpl_attrs[0] && !tmpl_attrs[1])
+ return 0;
+
+ /* Avoid warning if either declaration contains an attribute on
+ the white list below. */
+ const char* const whitelist[] = {
+ "error", "warning"
+ };
+
+ for (unsigned i = 0; i != 2; ++i)
+ for (unsigned j = 0; j != sizeof whitelist / sizeof *whitelist; ++j)
+ if (lookup_attribute (whitelist[j], tmpl_attrs[i])
+ || lookup_attribute (whitelist[j], decl_attrs[i]))
+ return 0;
+
+ /* Put together a list of the black-listed attributes that the template
+ is declared with and the declaration is not, in case it's not apparent
+ from the most recent declaration of the template. */
+ unsigned nattrs = 0;
+
+ for (unsigned i = 0; blacklist[i]; ++i)
+ {
+ /* Attribute leaf only applies to extern functions. Avoid mentioning
+ it when it's missing from a static declaration. */
+ if (!TREE_PUBLIC (decl)
+ && !strcmp ("leaf", blacklist[i]))
+ continue;
+
+ for (unsigned j = 0; j != 2; ++j)
+ {
+ if (!has_attribute (tmpls[j], tmpl_attrs[j], blacklist[i]))
+ continue;
+
+ bool found = false;
+ unsigned kmax = 1 + !!decl_attrs[1];
+ for (unsigned k = 0; k != kmax; ++k)
+ {
+ if (has_attribute (decls[k], decl_attrs[k], blacklist[i]))
+ {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ {
+ if (nattrs)
+ pp_string (attrstr, ", ");
+ pp_begin_quote (attrstr, pp_show_color (global_dc->printer));
+ pp_string (attrstr, blacklist[i]);
+ pp_end_quote (attrstr, pp_show_color (global_dc->printer));
+ ++nattrs;
+ }
+
+ break;
+ }
+ }
+
+ return nattrs;
+}
+
+/* Issue a warning for the declaration ALIAS for TARGET where ALIAS
+ specifies either attributes that are incompatible with those of
+ TARGET, or attributes that are missing and that declaring ALIAS
+ with would benefit. */
+
+void
+maybe_diag_alias_attributes (tree alias, tree target)
+{
+ /* Do not expect attributes to match between aliases and ifunc
+ resolvers. There is no obvious correspondence between them. */
+ if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (alias)))
+ return;
+
+ const char* const blacklist[] = {
+ "alloc_align", "alloc_size", "cold", "const", "hot", "leaf", "malloc",
+ "nonnull", "noreturn", "nothrow", "pure", "returns_nonnull",
+ "returns_twice", NULL
+ };
+
+ pretty_printer attrnames;
+ if (warn_attribute_alias > 1)
+ {
+ /* With -Wattribute-alias=2 detect alias declarations that are more
+ restrictive than their targets first. Those indicate potential
+ codegen bugs. */
+ if (unsigned n = decls_mismatched_attributes (alias, target, NULL_TREE,
+ blacklist, &attrnames))
+ {
+ auto_diagnostic_group d;
+ if (warning_n (DECL_SOURCE_LOCATION (alias),
+ OPT_Wattribute_alias_, n,
+ "%qD specifies more restrictive attribute than "
+ "its target %qD: %s",
+ "%qD specifies more restrictive attributes than "
+ "its target %qD: %s",
+ alias, target, pp_formatted_text (&attrnames)))
+ inform (DECL_SOURCE_LOCATION (target),
+ "%qD target declared here", alias);
+ return;
+ }
+ }
+
+ /* Detect alias declarations that are less restrictive than their
+ targets. Those suggest potential optimization opportunities
+ (solved by adding the missing attribute(s) to the alias). */
+ if (unsigned n = decls_mismatched_attributes (target, alias, NULL_TREE,
+ blacklist, &attrnames))
+ {
+ auto_diagnostic_group d;
+ if (warning_n (DECL_SOURCE_LOCATION (alias),
+ OPT_Wmissing_attributes, n,
+ "%qD specifies less restrictive attribute than "
+ "its target %qD: %s",
+ "%qD specifies less restrictive attributes than "
+ "its target %qD: %s",
+ alias, target, pp_formatted_text (&attrnames)))
+ inform (DECL_SOURCE_LOCATION (target),
+ "%qD target declared here", alias);
+ }
+}
+
+/* Initialize a mapping RWM for a call to a function declared with
+ attribute access in ATTRS. Each attribute positional operand
+ inserts one entry into the mapping with the operand number as
+ the key. */
+
+void
+init_attr_rdwr_indices (rdwr_map *rwm, tree attrs)
+{
+ if (!attrs)
+ return;
+
+ for (tree access = attrs;
+ (access = lookup_attribute ("access", access));
+ access = TREE_CHAIN (access))
+ {
+ /* The TREE_VALUE of an attribute is a TREE_LIST whose TREE_VALUE
+ is the attribute argument's value. */
+ tree mode = TREE_VALUE (access);
+ if (!mode)
+ return;
+
+ /* The (optional) list of VLA bounds. */
+ tree vblist = TREE_CHAIN (mode);
+ if (vblist)
+ vblist = TREE_VALUE (vblist);
+
+ mode = TREE_VALUE (mode);
+ if (TREE_CODE (mode) != STRING_CST)
+ continue;
+ gcc_assert (TREE_CODE (mode) == STRING_CST);
+
+ for (const char *m = TREE_STRING_POINTER (mode); *m; )
+ {
+ attr_access acc = { };
+
+ /* Skip the internal-only plus sign. */
+ if (*m == '+')
+ ++m;
+
+ acc.str = m;
+ acc.mode = acc.from_mode_char (*m);
+ acc.sizarg = UINT_MAX;
+
+ const char *end;
+ acc.ptrarg = strtoul (++m, const_cast<char**>(&end), 10);
+ m = end;
+
+ if (*m == '[')
+ {
+ /* Forms containing the square bracket are internal-only
+ (not specified by an attribute declaration), and used
+ for various forms of array and VLA parameters. */
+ acc.internal_p = true;
+
+ /* Search to the closing bracket and look at the preceding
+ code: it determines the form of the most significant
+ bound of the array. Others prior to it encode the form
+ of interior VLA bounds. They're not of interest here. */
+ end = strchr (m, ']');
+ const char *p = end;
+ gcc_assert (p);
+
+ while (ISDIGIT (p[-1]))
+ --p;
+
+ if (ISDIGIT (*p))
+ {
+ /* A digit denotes a constant bound (as in T[3]). */
+ acc.static_p = p[-1] == 's';
+ acc.minsize = strtoull (p, NULL, 10);
+ }
+ else if (' ' == p[-1])
+ {
+ /* A space denotes an ordinary array of unspecified bound
+ (as in T[]). */
+ acc.minsize = 0;
+ }
+ else if ('*' == p[-1] || '$' == p[-1])
+ {
+ /* An asterisk denotes a VLA. When the closing bracket
+ is followed by a comma and a dollar sign its bound is
+ on the list. Otherwise it's a VLA with an unspecified
+ bound. */
+ acc.static_p = p[-2] == 's';
+ acc.minsize = HOST_WIDE_INT_M1U;
+ }
+
+ m = end + 1;
+ }
+
+ if (*m == ',')
+ {
+ ++m;
+ do
+ {
+ if (*m == '$')
+ {
+ ++m;
+ if (!acc.size)
+ {
+ /* Extract the list of VLA bounds for the current
+ parameter, store it in ACC.SIZE, and advance
+ to the list of bounds for the next VLA parameter.
+ */
+ acc.size = TREE_VALUE (vblist);
+ vblist = TREE_CHAIN (vblist);
+ }
+ }
+
+ if (ISDIGIT (*m))
+ {
+ /* Extract the positional argument. It's absent
+ for VLAs whose bound doesn't name a function
+ parameter. */
+ unsigned pos = strtoul (m, const_cast<char**>(&end), 10);
+ if (acc.sizarg == UINT_MAX)
+ acc.sizarg = pos;
+ m = end;
+ }
+ }
+ while (*m == '$');
+ }
+
+ acc.end = m;
+
+ bool existing;
+ auto &ref = rwm->get_or_insert (acc.ptrarg, &existing);
+ if (existing)
+ {
+ /* Merge the new spec with the existing. */
+ if (acc.minsize == HOST_WIDE_INT_M1U)
+ ref.minsize = HOST_WIDE_INT_M1U;
+
+ if (acc.sizarg != UINT_MAX)
+ ref.sizarg = acc.sizarg;
+
+ if (acc.mode)
+ ref.mode = acc.mode;
+ }
+ else
+ ref = acc;
+
+ /* Unconditionally add an entry for the required pointer
+ operand of the attribute, and one for the optional size
+ operand when it's specified. */
+ if (acc.sizarg != UINT_MAX)
+ rwm->put (acc.sizarg, acc);
+ }
+ }
+}
+
+/* Return the access specification for a function parameter PARM
+ or null if the current function has no such specification. */
+
+attr_access *
+get_parm_access (rdwr_map &rdwr_idx, tree parm,
+ tree fndecl /* = current_function_decl */)
+{
+ tree fntype = TREE_TYPE (fndecl);
+ init_attr_rdwr_indices (&rdwr_idx, TYPE_ATTRIBUTES (fntype));
+
+ if (rdwr_idx.is_empty ())
+ return NULL;
+
+ unsigned argpos = 0;
+ tree fnargs = DECL_ARGUMENTS (fndecl);
+ for (tree arg = fnargs; arg; arg = TREE_CHAIN (arg), ++argpos)
+ if (arg == parm)
+ return rdwr_idx.get (argpos);
+
+ return NULL;
+}
+
+/* Return the internal representation as STRING_CST. Internal positional
+ arguments are zero-based. */
+
+tree
+attr_access::to_internal_string () const
+{
+ return build_string (end - str, str);
+}
+
+/* Return the human-readable representation of the external attribute
+ specification (as it might appear in the source code) as STRING_CST.
+ External positional arguments are one-based. */
+
+tree
+attr_access::to_external_string () const
+{
+ char buf[80];
+ gcc_assert (mode != access_deferred);
+ int len = snprintf (buf, sizeof buf, "access (%s, %u",
+ mode_names[mode], ptrarg + 1);
+ if (sizarg != UINT_MAX)
+ len += snprintf (buf + len, sizeof buf - len, ", %u", sizarg + 1);
+ strcpy (buf + len, ")");
+ return build_string (len + 2, buf);
+}
+
+/* Return the number of specified VLA bounds and set *nunspec to
+ the number of unspecified ones (those designated by [*]). */
+
+unsigned
+attr_access::vla_bounds (unsigned *nunspec) const
+{
+ *nunspec = 0;
+ for (const char* p = strrchr (str, ']'); p && *p != '['; --p)
+ if (*p == '*')
+ ++*nunspec;
+ return list_length (size);
+}
+
+
+/* Defined in attr_access. */
+constexpr char attr_access::mode_chars[];
+constexpr char attr_access::mode_names[][11];
+
+/* Format an array, including a VLA, pointed to by TYPE and used as
+ a function parameter as a human-readable string. ACC describes
+ an access to the parameter and is used to determine the outermost
+ form of the array including its bound which is otherwise obviated
+ by its decay to pointer. Return the formatted string. */
+
+std::string
+attr_access::array_as_string (tree type) const
+{
+ std::string typstr;
+
+ if (type == error_mark_node)
+ return std::string ();
+
+ if (this->str)
+ {
+ /* For array parameters (but not pointers) create a temporary array
+ type that corresponds to the form of the parameter including its
+ qualifiers even though they apply to the pointer, not the array
+ type. */
+ const bool vla_p = minsize == HOST_WIDE_INT_M1U;
+ tree eltype = TREE_TYPE (type);
+ tree index_type = NULL_TREE;
+
+ if (minsize == HOST_WIDE_INT_M1U)
+ {
+ /* Determine if this is a VLA (an array whose most significant
+ bound is nonconstant and whose access string has "$]" in it)
+ extract the bound expression from SIZE. */
+ const char *p = end;
+ for ( ; p != str && *p-- != ']'; );
+ if (*p == '$')
+ index_type = build_index_type (TREE_VALUE (size));
+ }
+ else if (minsize)
+ index_type = build_index_type (size_int (minsize - 1));
+
+ tree arat = NULL_TREE;
+ if (static_p || vla_p)
+ {
+ tree flag = static_p ? integer_one_node : NULL_TREE;
+ /* Hack: there's no language-independent way to encode
+ the "static" specifier or the "*" notation in an array type.
+ Add a "fake" attribute to have the pretty-printer add "static"
+ or "*". The "[static N]" notation is only valid in the most
+ significant bound but [*] can be used for any bound. Because
+ [*] is represented the same as [0] this hack only works for
+ the most significant bound like static and the others are
+ rendered as [0]. */
+ arat = build_tree_list (get_identifier ("array"), flag);
+ }
+
+ const int quals = TYPE_QUALS (type);
+ type = build_array_type (eltype, index_type);
+ type = build_type_attribute_qual_variant (type, arat, quals);
+ }
+
+ /* Format the type using the current pretty printer. The generic tree
+ printer does a terrible job. */
+ pretty_printer *pp = global_dc->printer->clone ();
+ pp_printf (pp, "%qT", type);
+ typstr = pp_formatted_text (pp);
+ delete pp;
+
+ return typstr;
+}
+
+#if CHECKING_P
+
+namespace selftest
+{
+
+/* Helper types to verify the consistency attribute exclusions. */
+
+typedef std::pair<const char *, const char *> excl_pair;
+
+struct excl_hash_traits: typed_noop_remove<excl_pair>
+{
+ typedef excl_pair value_type;
+ typedef value_type compare_type;
+
+ static hashval_t hash (const value_type &x)
+ {
+ hashval_t h1 = htab_hash_string (x.first);
+ hashval_t h2 = htab_hash_string (x.second);
+ return h1 ^ h2;
+ }
+
+ static bool equal (const value_type &x, const value_type &y)
+ {
+ return !strcmp (x.first, y.first) && !strcmp (x.second, y.second);
+ }
+
+ static void mark_deleted (value_type &x)
+ {
+ x = value_type (NULL, NULL);
+ }
+
+ static const bool empty_zero_p = false;
+
+ static void mark_empty (value_type &x)
+ {
+ x = value_type ("", "");
+ }
+
+ static bool is_deleted (const value_type &x)
+ {
+ return !x.first && !x.second;
+ }
+
+ static bool is_empty (const value_type &x)
+ {
+ return !*x.first && !*x.second;
+ }
+};
+
+
+/* Self-test to verify that each attribute exclusion is symmetric,
+ meaning that if attribute A is encoded as incompatible with
+ attribute B then the opposite relationship is also encoded.
+ This test also detects most cases of misspelled attribute names
+ in exclusions. */
+
+static void
+test_attribute_exclusions ()
+{
+ /* Iterate over the array of attribute tables first (with TI0 as
+ the index) and over the array of attribute_spec in each table
+ (with SI0 as the index). */
+ const size_t ntables = ARRAY_SIZE (attribute_tables);
+
+ /* Set of pairs of mutually exclusive attributes. */
+ typedef hash_set<excl_pair, false, excl_hash_traits> exclusion_set;
+ exclusion_set excl_set;
+
+ for (size_t ti0 = 0; ti0 != ntables; ++ti0)
+ for (size_t s0 = 0; attribute_tables[ti0][s0].name; ++s0)
+ {
+ const attribute_spec::exclusions *excl
+ = attribute_tables[ti0][s0].exclude;
+
+ /* Skip each attribute that doesn't define exclusions. */
+ if (!excl)
+ continue;
+
+ const char *attr_name = attribute_tables[ti0][s0].name;
+
+ /* Iterate over the set of exclusions for every attribute
+ (with EI0 as the index) adding the exclusions defined
+ for each to the set. */
+ for (size_t ei0 = 0; excl[ei0].name; ++ei0)
+ {
+ const char *excl_name = excl[ei0].name;
+
+ if (!strcmp (attr_name, excl_name))
+ continue;
+
+ excl_set.add (excl_pair (attr_name, excl_name));
+ }
+ }
+
+ /* Traverse the set of mutually exclusive pairs of attributes
+ and verify that they are symmetric. */
+ for (exclusion_set::iterator it = excl_set.begin ();
+ it != excl_set.end ();
+ ++it)
+ {
+ if (!excl_set.contains (excl_pair ((*it).second, (*it).first)))
+ {
+ /* An exclusion for an attribute has been found that
+ doesn't have a corresponding exclusion in the opposite
+ direction. */
+ char desc[120];
+ sprintf (desc, "'%s' attribute exclusion '%s' must be symmetric",
+ (*it).first, (*it).second);
+ fail (SELFTEST_LOCATION, desc);
+ }
+ }
+}
+
+void
+attribute_c_tests ()
+{
+ test_attribute_exclusions ();
+}
+
+} /* namespace selftest */
+
+#endif /* CHECKING_P */
projects / gcc.git / blobdiff