tree
make_thunk (tree function, bool this_adjusting,
tree fixed_offset, tree virtual_offset)
{
HOST_WIDE_INT d;
tree thunk;
gcc_assert (TREE_CODE (function) == FUNCTION_DECL);
/* We can have this thunks to covariant thunks, but not vice versa. */
gcc_assert (!DECL_THIS_THUNK_P (function));
gcc_assert (!DECL_RESULT_THUNK_P (function) || this_adjusting);
/* Scale the VIRTUAL_OFFSET to be in terms of bytes. */
if (this_adjusting && virtual_offset)
virtual_offset
= size_binop (MULT_EXPR,
virtual_offset,
convert (ssizetype,
TYPE_SIZE_UNIT (vtable_entry_type)));
d = tree_low_cst (fixed_offset, 0);
/* See if we already have the thunk in question. For this_adjusting
thunks VIRTUAL_OFFSET will be an INTEGER_CST, for covariant thunks it
will be a BINFO. */
for (thunk = DECL_THUNKS (function); thunk; thunk = TREE_CHAIN (thunk))
if (DECL_THIS_THUNK_P (thunk) == this_adjusting
&& THUNK_FIXED_OFFSET (thunk) == d
&& !virtual_offset == !THUNK_VIRTUAL_OFFSET (thunk)
&& (!virtual_offset
|| (this_adjusting
? tree_int_cst_equal (THUNK_VIRTUAL_OFFSET (thunk),
virtual_offset)
: THUNK_VIRTUAL_OFFSET (thunk) == virtual_offset)))
return thunk;
/* All thunks must be created before FUNCTION is actually emitted;
the ABI requires that all thunks be emitted together with the
function to which they transfer control. */
gcc_assert (!TREE_ASM_WRITTEN (function));
/* Likewise, we can only be adding thunks to a function declared in
the class currently being laid out. */
gcc_assert (TYPE_SIZE (DECL_CONTEXT (function))
&& TYPE_BEING_DEFINED (DECL_CONTEXT (function)));
thunk = build_decl (FUNCTION_DECL, NULL_TREE, TREE_TYPE (function));
DECL_LANG_SPECIFIC (thunk) = DECL_LANG_SPECIFIC (function);
cxx_dup_lang_specific_decl (thunk);
DECL_THUNKS (thunk) = NULL_TREE;
DECL_CONTEXT (thunk) = DECL_CONTEXT (function);
TREE_READONLY (thunk) = TREE_READONLY (function);
TREE_THIS_VOLATILE (thunk) = TREE_THIS_VOLATILE (function);
TREE_PUBLIC (thunk) = TREE_PUBLIC (function);
SET_DECL_THUNK_P (thunk, this_adjusting);
THUNK_TARGET (thunk) = function;
THUNK_FIXED_OFFSET (thunk) = d;
THUNK_VIRTUAL_OFFSET (thunk) = virtual_offset;
THUNK_ALIAS (thunk) = NULL_TREE;
/* The thunk itself is not a constructor or destructor, even if
the thing it is thunking to is. */
DECL_INTERFACE_KNOWN (thunk) = 1;
DECL_NOT_REALLY_EXTERN (thunk) = 1;
DECL_SAVED_FUNCTION_DATA (thunk) = NULL;
DECL_DESTRUCTOR_P (thunk) = 0;
DECL_CONSTRUCTOR_P (thunk) = 0;
DECL_EXTERNAL (thunk) = 1;
DECL_ARTIFICIAL (thunk) = 1;
/* Even if this thunk is a member of a local class, we don't
need a static chain. */
DECL_NO_STATIC_CHAIN (thunk) = 1;
/* The THUNK is not a pending inline, even if the FUNCTION is. */
DECL_PENDING_INLINE_P (thunk) = 0;
DECL_INLINE (thunk) = 0;
DECL_DECLARED_INLINE_P (thunk) = 0;
/* Nor has it been deferred. */
DECL_DEFERRED_FN (thunk) = 0;
/* Nor is it a template instantiation. */
DECL_USE_TEMPLATE (thunk) = 0;
DECL_TEMPLATE_INFO (thunk) = NULL;
/* Add it to the list of thunks associated with FUNCTION. */
TREE_CHAIN (thunk) = DECL_THUNKS (function);
DECL_THUNKS (function) = thunk;
return thunk;
}
bool
gcc_cp_dump_tree (void* dump_info, tree t)
{
enum tree_code code;
dump_info_p di = (dump_info_p) dump_info;
/* Figure out what kind of node this is. */
code = TREE_CODE (t);
if (DECL_P (t))
{
if (DECL_LANG_SPECIFIC (t) && DECL_LANGUAGE (t) != lang_cplusplus)
gcc_dump_string_field (di, "lang", language_to_string (DECL_LANGUAGE (t)));
}
switch (code)
{
case IDENTIFIER_NODE:
if (IDENTIFIER_OPNAME_P (t))
{
gcc_dump_string_field (di, "note", "operator");
return true;
}
else if (IDENTIFIER_TYPENAME_P (t))
{
dump_child ("tynm", TREE_TYPE (t));
return true;
}
break;
case OFFSET_TYPE:
gcc_dump_string_field (di, "note", "ptrmem");
dump_child ("ptd", TYPE_PTRMEM_POINTED_TO_TYPE (t));
dump_child ("cls", TYPE_PTRMEM_CLASS_TYPE (t));
return true;
case RECORD_TYPE:
if (TYPE_PTRMEMFUNC_P (t))
{
gcc_dump_string_field (di, "note", "ptrmem");
dump_child ("ptd", TYPE_PTRMEM_POINTED_TO_TYPE (t));
dump_child ("cls", TYPE_PTRMEM_CLASS_TYPE (t));
return true;
}
/* Fall through. */
case UNION_TYPE:
/* Is it a type used as a base? */
if (TYPE_CONTEXT (t) && TREE_CODE (TYPE_CONTEXT (t)) == TREE_CODE (t)
&& CLASSTYPE_AS_BASE (TYPE_CONTEXT (t)) == t)
{
dump_child ("bfld", TYPE_CONTEXT (t));
return true;
}
if (! MAYBE_CLASS_TYPE_P (t))
break;
dump_child ("vfld", TYPE_VFIELD (t));
if (CLASSTYPE_TEMPLATE_SPECIALIZATION(t))
gcc_dump_string(di, "spec");
if (!dump_flag (di, TDF_SLIM, t) && TYPE_BINFO (t))
{
int i;
tree binfo;
tree base_binfo;
for (binfo = TYPE_BINFO (t), i = 0;
BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
{
dump_child ("base", BINFO_TYPE (base_binfo));
if (BINFO_VIRTUAL_P (base_binfo))
gcc_dump_string_field (di, "spec", "virt");
dump_access (di, base_binfo);
}
}
break;
case FIELD_DECL:
dump_access (di, t);
if (DECL_MUTABLE_P (t))
gcc_dump_string_field (di, "spec", "mutable");
break;
case VAR_DECL:
if (TREE_CODE (CP_DECL_CONTEXT (t)) == RECORD_TYPE)
dump_access (di, t);
if (TREE_STATIC (t) && !TREE_PUBLIC (t))
gcc_dump_string_field (di, "link", "static");
break;
case FUNCTION_DECL:
if (!DECL_THUNK_P (t))
{
if (DECL_OVERLOADED_OPERATOR_P (t)) {
gcc_dump_string_field (di, "note", "operator");
dump_op (di, t);
}
if (DECL_FUNCTION_MEMBER_P (t))
{
gcc_dump_string_field (di, "note", "member");
dump_access (di, t);
}
if (DECL_PURE_VIRTUAL_P (t))
gcc_dump_string_field (di, "spec", "pure");
if (DECL_VIRTUAL_P (t))
gcc_dump_string_field (di, "spec", "virt");
if (DECL_CONSTRUCTOR_P (t))
gcc_dump_string_field (di, "note", "constructor");
if (DECL_DESTRUCTOR_P (t))
gcc_dump_string_field (di, "note", "destructor");
if (DECL_CONV_FN_P (t))
gcc_dump_string_field (di, "note", "conversion");
if (DECL_GLOBAL_CTOR_P (t))
gcc_dump_string_field (di, "note", "global init");
if (DECL_GLOBAL_DTOR_P (t))
gcc_dump_string_field (di, "note", "global fini");
if (DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (t))
gcc_dump_string_field (di, "note", "pseudo tmpl");
}
else
{
tree virt = THUNK_VIRTUAL_OFFSET (t);
gcc_dump_string_field (di, "note", "thunk");
if (DECL_THIS_THUNK_P (t))
gcc_dump_string_field (di, "note", "this adjusting");
else
{
gcc_dump_string_field (di, "note", "result adjusting");
if (virt)
virt = BINFO_VPTR_FIELD (virt);
}
gcc_dump_int (di, "fixd", THUNK_FIXED_OFFSET (t));
if (virt)
gcc_dump_int (di, "virt", tree_low_cst (virt, 0));
dump_child ("fn", DECL_INITIAL (t));
}
break;
case NAMESPACE_DECL:
if (DECL_NAMESPACE_ALIAS (t))
dump_child ("alis", DECL_NAMESPACE_ALIAS (t));
else if (!dump_flag (di, TDF_SLIM, t))
dump_child ("dcls", cp_namespace_decls (t));
break;
case TEMPLATE_DECL:
dump_child ("rslt", DECL_TEMPLATE_RESULT (t));
dump_child ("inst", DECL_TEMPLATE_INSTANTIATIONS (t));
dump_child ("spcs", DECL_TEMPLATE_SPECIALIZATIONS (t));
dump_child ("prms", DECL_TEMPLATE_PARMS (t));
break;
case OVERLOAD:
dump_child ("crnt", OVL_CURRENT (t));
dump_child ("chan", OVL_CHAIN (t));
break;
case TRY_BLOCK:
gcc_dump_stmt (di, t);
if (CLEANUP_P (t))
dump_string_field (di, "note", "cleanup");
dump_child ("body", TRY_STMTS (t));
dump_child ("hdlr", TRY_HANDLERS (t));
break;
case EH_SPEC_BLOCK:
gcc_dump_stmt (di, t);
dump_child ("body", EH_SPEC_STMTS (t));
dump_child ("raises", EH_SPEC_RAISES (t));
break;
case PTRMEM_CST:
dump_child ("clas", PTRMEM_CST_CLASS (t));
dump_child ("mbr", PTRMEM_CST_MEMBER (t));
break;
case THROW_EXPR:
/* These nodes are unary, but do not have code class `1'. */
dump_child ("op 0", TREE_OPERAND (t, 0));
break;
// case AGGR_INIT_EXPR:
// {
// int i = 0;
// tree arg;
// aggr_init_expr_arg_iterator iter;
// gcc_dump_int (di, "ctor", AGGR_INIT_VIA_CTOR_P (t));
// dump_child ("fn", AGGR_INIT_EXPR_FN (t));
// FOR_EACH_AGGR_INIT_EXPR_ARG (arg, iter, t)
// {
// char buffer[32];
// sprintf (buffer, "%u", i);
// dump_child (buffer, arg);
// i++;
// }
// dump_child ("decl", AGGR_INIT_EXPR_SLOT (t));
// }
// break;
case HANDLER:
gcc_dump_stmt (di, t);
dump_child ("parm", HANDLER_PARMS (t));
dump_child ("body", HANDLER_BODY (t));
break;
case MUST_NOT_THROW_EXPR:
gcc_dump_stmt (di, t);
dump_child ("body", TREE_OPERAND (t, 0));
break;
case USING_STMT:
gcc_dump_stmt (di, t);
dump_child ("nmsp", USING_STMT_NAMESPACE (t));
break;
case CLEANUP_STMT:
gcc_dump_stmt (di, t);
dump_child ("decl", CLEANUP_DECL (t));
dump_child ("expr", CLEANUP_EXPR (t));
dump_child ("body", CLEANUP_BODY (t));
break;
case IF_STMT:
gcc_dump_stmt (di, t);
dump_child ("cond", IF_COND (t));
dump_child ("then", THEN_CLAUSE (t));
dump_child ("else", ELSE_CLAUSE (t));
break;
case BREAK_STMT:
case CONTINUE_STMT:
gcc_dump_stmt (di, t);
break;
case DO_STMT:
gcc_dump_stmt (di, t);
dump_child ("body", DO_BODY (t));
dump_child ("cond", DO_COND (t));
break;
case FOR_STMT:
gcc_dump_stmt (di, t);
dump_child ("init", FOR_INIT_STMT (t));
dump_child ("cond", FOR_COND (t));
dump_child ("expr", FOR_EXPR (t));
dump_child ("body", FOR_BODY (t));
break;
case RANGE_FOR_STMT:
gcc_dump_stmt (di, t);
dump_child ("decl", RANGE_FOR_DECL (t));
dump_child ("expr", RANGE_FOR_EXPR (t));
dump_child ("body", RANGE_FOR_BODY (t));
break;
case SWITCH_STMT:
gcc_dump_stmt (di, t);
dump_child ("cond", SWITCH_STMT_COND (t));
dump_child ("body", SWITCH_STMT_BODY (t));
break;
case WHILE_STMT:
gcc_dump_stmt (di, t);
dump_child ("cond", WHILE_COND (t));
dump_child ("body", WHILE_BODY (t));
break;
case STMT_EXPR:
dump_child ("stmt", STMT_EXPR_STMT (t));
break;
case EXPR_STMT:
gcc_dump_stmt (di, t);
dump_child ("expr", EXPR_STMT_EXPR (t));
break;
default:
break;
}
return gcc_c_dump_tree (di, t);
}
void
use_thunk (tree thunk_fndecl, bool emit_p)
{
tree a, t, function, alias;
tree virtual_offset;
HOST_WIDE_INT fixed_offset, virtual_value;
bool this_adjusting = DECL_THIS_THUNK_P (thunk_fndecl);
/* We should have called finish_thunk to give it a name. */
gcc_assert (DECL_NAME (thunk_fndecl));
/* We should never be using an alias, always refer to the
aliased thunk. */
gcc_assert (!THUNK_ALIAS (thunk_fndecl));
if (TREE_ASM_WRITTEN (thunk_fndecl))
return;
function = THUNK_TARGET (thunk_fndecl);
if (DECL_RESULT (thunk_fndecl))
/* We already turned this thunk into an ordinary function.
There's no need to process this thunk again. */
return;
if (DECL_THUNK_P (function))
/* The target is itself a thunk, process it now. */
use_thunk (function, emit_p);
/* Thunks are always addressable; they only appear in vtables. */
TREE_ADDRESSABLE (thunk_fndecl) = 1;
/* Figure out what function is being thunked to. It's referenced in
this translation unit. */
TREE_ADDRESSABLE (function) = 1;
mark_used (function);
if (!emit_p)
return;
if (TARGET_USE_LOCAL_THUNK_ALIAS_P (function))
alias = make_alias_for_thunk (function);
else
alias = function;
fixed_offset = THUNK_FIXED_OFFSET (thunk_fndecl);
virtual_offset = THUNK_VIRTUAL_OFFSET (thunk_fndecl);
if (virtual_offset)
{
if (!this_adjusting)
virtual_offset = BINFO_VPTR_FIELD (virtual_offset);
virtual_value = tree_low_cst (virtual_offset, /*pos=*/0);
gcc_assert (virtual_value);
}
else
virtual_value = 0;
/* And, if we need to emit the thunk, it's used. */
mark_used (thunk_fndecl);
/* This thunk is actually defined. */
DECL_EXTERNAL (thunk_fndecl) = 0;
/* The linkage of the function may have changed. FIXME in linkage
rewrite. */
TREE_PUBLIC (thunk_fndecl) = TREE_PUBLIC (function);
DECL_VISIBILITY (thunk_fndecl) = DECL_VISIBILITY (function);
DECL_VISIBILITY_SPECIFIED (thunk_fndecl)
= DECL_VISIBILITY_SPECIFIED (function);
if (DECL_ONE_ONLY (function))
make_decl_one_only (thunk_fndecl);
if (flag_syntax_only)
{
TREE_ASM_WRITTEN (thunk_fndecl) = 1;
return;
}
push_to_top_level ();
if (TARGET_USE_LOCAL_THUNK_ALIAS_P (function)
&& targetm.have_named_sections)
{
resolve_unique_section (function, 0, flag_function_sections);
if (DECL_SECTION_NAME (function) != NULL && DECL_ONE_ONLY (function))
{
resolve_unique_section (thunk_fndecl, 0, flag_function_sections);
/* Output the thunk into the same section as function. */
DECL_SECTION_NAME (thunk_fndecl) = DECL_SECTION_NAME (function);
}
}
#ifdef KEY
if (flag_spin_file)
gspin_gxx_emits_thunk_decl (thunk_fndecl); // generate code for the thunk
#endif
/* The back-end expects DECL_INITIAL to contain a BLOCK, so we
create one. */
DECL_INITIAL (thunk_fndecl) = make_node (BLOCK);
/* Set up cloned argument trees for the thunk. */
t = NULL_TREE;
for (a = DECL_ARGUMENTS (function); a; a = TREE_CHAIN (a))
{
tree x = copy_node (a);
TREE_CHAIN (x) = t;
DECL_CONTEXT (x) = thunk_fndecl;
SET_DECL_RTL (x, NULL_RTX);
DECL_HAS_VALUE_EXPR_P (x) = 0;
t = x;
}
a = nreverse (t);
DECL_ARGUMENTS (thunk_fndecl) = a;
BLOCK_VARS (DECL_INITIAL (thunk_fndecl)) = a;
if (this_adjusting
&& targetm.asm_out.can_output_mi_thunk (thunk_fndecl, fixed_offset,
virtual_value, alias))
{
const char *fnname;
current_function_decl = thunk_fndecl;
DECL_RESULT (thunk_fndecl)
= build_decl (RESULT_DECL, 0, integer_type_node);
fnname = XSTR (XEXP (DECL_RTL (thunk_fndecl), 0), 0);
init_function_start (thunk_fndecl);
current_function_is_thunk = 1;
assemble_start_function (thunk_fndecl, fnname);
targetm.asm_out.output_mi_thunk (asm_out_file, thunk_fndecl,
fixed_offset, virtual_value, alias);
assemble_end_function (thunk_fndecl, fnname);
init_insn_lengths ();
current_function_decl = 0;
cfun = 0;
TREE_ASM_WRITTEN (thunk_fndecl) = 1;
}
else
{
/* If this is a covariant thunk, or we don't have the necessary
code for efficient thunks, generate a thunk function that
just makes a call to the real function. Unfortunately, this
doesn't work for varargs. */
if (varargs_function_p (function))
error ("generic thunk code fails for method %q#D which uses %<...%>",
function);
DECL_RESULT (thunk_fndecl) = NULL_TREE;
start_preparsed_function (thunk_fndecl, NULL_TREE, SF_PRE_PARSED);
/* We don't bother with a body block for thunks. */
/* There's no need to check accessibility inside the thunk body. */
push_deferring_access_checks (dk_no_check);
t = a;
if (this_adjusting)
t = thunk_adjust (t, /*this_adjusting=*/1,
fixed_offset, virtual_offset);
/* Build up the call to the real function. */
t = tree_cons (NULL_TREE, t, NULL_TREE);
for (a = TREE_CHAIN (a); a; a = TREE_CHAIN (a))
t = tree_cons (NULL_TREE, a, t);
t = nreverse (t);
t = build_call (alias, t);
CALL_FROM_THUNK_P (t) = 1;
if (VOID_TYPE_P (TREE_TYPE (t)))
finish_expr_stmt (t);
else
{
if (!this_adjusting)
{
tree cond = NULL_TREE;
if (TREE_CODE (TREE_TYPE (t)) == POINTER_TYPE)
{
/* If the return type is a pointer, we need to
protect against NULL. We know there will be an
adjustment, because that's why we're emitting a
thunk. */
t = save_expr (t);
cond = cp_convert (boolean_type_node, t);
}
t = thunk_adjust (t, /*this_adjusting=*/0,
fixed_offset, virtual_offset);
if (cond)
t = build3 (COND_EXPR, TREE_TYPE (t), cond, t,
cp_convert (TREE_TYPE (t), integer_zero_node));
}
if (IS_AGGR_TYPE (TREE_TYPE (t)))
t = build_cplus_new (TREE_TYPE (t), t);
finish_return_stmt (t);
}
/* Since we want to emit the thunk, we explicitly mark its name as
referenced. */
mark_decl_referenced (thunk_fndecl);
/* But we don't want debugging information about it. */
DECL_IGNORED_P (thunk_fndecl) = 1;
/* Re-enable access control. */
pop_deferring_access_checks ();
thunk_fndecl = finish_function (0);
tree_lowering_passes (thunk_fndecl);
expand_body (thunk_fndecl);
}
pop_from_top_level ();
}
