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Diffstat (limited to 'gnu/usr.bin/cc/cc1plus/sig.c')
| -rw-r--r-- | gnu/usr.bin/cc/cc1plus/sig.c | 1023 |
1 files changed, 1023 insertions, 0 deletions
diff --git a/gnu/usr.bin/cc/cc1plus/sig.c b/gnu/usr.bin/cc/cc1plus/sig.c new file mode 100644 index 0000000..1426168 --- /dev/null +++ b/gnu/usr.bin/cc/cc1plus/sig.c @@ -0,0 +1,1023 @@ +/* Functions dealing with signatures and signature pointers/references. + Copyright (C) 1992 Free Software Foundation, Inc. + Contributed by Gerald Baumgartner (gb@cs.purdue.edu) + +This file is part of GNU CC. + +GNU CC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU CC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU CC; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + + +#include "config.h" +#include <stdio.h> +#include "obstack.h" +#include "tree.h" +#include "cp-tree.h" +#include "flags.h" +#include "assert.h" + +extern struct obstack *current_obstack; +extern struct obstack permanent_obstack; +extern struct obstack *saveable_obstack; + +extern void error (); +extern void sorry (); +extern void compiler_error (); +extern void make_decl_rtl PROTO((tree, char *, int)); + +/* Used to help generate globally unique names for signature tables. */ + +static int global_sigtable_name_counter; + +/* Build an identifier for a signature pointer or reference, so we + can use it's name in function name mangling. */ + +static tree +build_signature_pointer_or_reference_name (to_type, constp, volatilep, refp) + tree to_type; + int constp, volatilep, refp; +{ + char * sig_name = TYPE_NAME_STRING (to_type); + int name_len = TYPE_NAME_LENGTH (to_type) + constp + volatilep; + char * name; + + if (refp) + { + name = (char *) alloca (name_len + sizeof (SIGNATURE_REFERENCE_NAME) +2); + sprintf (name, SIGNATURE_REFERENCE_NAME_FORMAT, + constp ? "C" : "", volatilep ? "V": "", sig_name); + } + else + { + name = (char *) alloca (name_len + sizeof (SIGNATURE_POINTER_NAME) + 2); + sprintf (name, SIGNATURE_POINTER_NAME_FORMAT, + constp ? "C" : "", volatilep ? "V": "", sig_name); + } + return get_identifier (name); +} + +/* Build a DECL node for a signature pointer or reference, so we can + tell the debugger the structure of signature pointers/references. + This function is called at most eight times for a given signature, + once for each [const] [volatile] signature pointer/reference. */ + +static void +build_signature_pointer_or_reference_decl (type, name) + tree type, name; +{ + tree decl; + + /* We don't enter this declaration in any sort of symbol table. */ + decl = build_decl (TYPE_DECL, name, type); + TYPE_NAME (type) = decl; + TREE_CHAIN (type) = decl; +} + +/* Construct, lay out and return the type of pointers or references + to signature TO_TYPE. If such a type has already been constructed, + reuse it. If CONSTP or VOLATILEP is specified, make the `optr' const + or volatile, respectively. If we are constructing a const/volatile + type variant and the main type variant doesn't exist yet, it is built + as well. If REFP is 1, we construct a signature reference, otherwise + a signature pointer is constructed. + + This function is a subroutine of `build_signature_pointer_type' and + `build_signature_reference_type'. */ + +static tree +build_signature_pointer_or_reference_type (to_type, constp, volatilep, refp) + tree to_type; + int constp, volatilep, refp; +{ + register tree t, m; + register struct obstack *ambient_obstack = current_obstack; + register struct obstack *ambient_saveable_obstack = saveable_obstack; + + m = refp ? SIGNATURE_REFERENCE_TO (to_type) : SIGNATURE_POINTER_TO (to_type); + + /* If we don't have the main variant yet, construct it. */ + if (m == NULL_TREE + && (constp || volatilep)) + m = build_signature_pointer_or_reference_type (to_type, 0, 0, refp); + + /* Treat any nonzero argument as 1. */ + constp = !!constp; + volatilep = !!volatilep; + refp = !!refp; + + /* If not generating auxiliary info, search the chain of variants to see + if there is already one there just like the one we need to have. If so, + use that existing one. + + We don't do this in the case where we are generating aux info because + in that case we want each typedef names to get it's own distinct type + node, even if the type of this new typedef is the same as some other + (existing) type. */ + + if (m && !flag_gen_aux_info) + for (t = m; t; t = TYPE_NEXT_VARIANT (t)) + if (constp == TYPE_READONLY (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (t)))) + && volatilep == TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (t))))) + return t; + + /* We need a new one. If TO_TYPE is permanent, make this permanent too. */ + if (TREE_PERMANENT (to_type)) + { + current_obstack = &permanent_obstack; + saveable_obstack = &permanent_obstack; + } + + /* A signature pointer or reference to a signature `s' looks like this: + + struct { + void * optr; + const s * sptr; + vtbl_type_node * vptr; + }; + + A `const' signature pointer/reference is a + + struct { + const void * optr; + const s * sptr; + vtbl_type_node * vptr; + }; + + Similarly, for `volatile' and `const volatile'. + */ + + t = make_lang_type (RECORD_TYPE); + { + tree obj_type = build_type_variant (void_type_node, constp, volatilep); + tree optr_type = build_pointer_type (obj_type); + tree optr, sptr, vptr; + + optr = build_lang_field_decl (FIELD_DECL, + get_identifier (SIGNATURE_OPTR_NAME), + optr_type); + DECL_FIELD_CONTEXT (optr) = t; + DECL_CLASS_CONTEXT (optr) = t; + + if (m) + { + /* We can share `sptr' and `vptr' among type variants. */ + sptr = TREE_CHAIN (TYPE_FIELDS (m)); + vptr = TREE_CHAIN (sptr); + } + else + { + tree sig_tbl_type = c_build_type_variant (to_type, 1, 0); + + sptr = build_lang_field_decl (FIELD_DECL, + get_identifier (SIGNATURE_SPTR_NAME), + build_pointer_type (sig_tbl_type)); + vptr = build_lang_field_decl (FIELD_DECL, + get_identifier (SIGNATURE_VPTR_NAME), + build_pointer_type (vtbl_type_node)); + DECL_FIELD_CONTEXT (sptr) = t; + DECL_CLASS_CONTEXT (sptr) = t; + DECL_FIELD_CONTEXT (vptr) = t; + DECL_CLASS_CONTEXT (vptr) = t; + TREE_CHAIN (sptr) = vptr; + TREE_CHAIN (vptr) = NULL_TREE; + } + + TREE_CHAIN (optr) = sptr; + TYPE_FIELDS (t) = optr; + /* To make `build_vfn_ref' work when building a signature method call. */ + CLASSTYPE_VFIELD (t) = vptr; + DECL_FCONTEXT (CLASSTYPE_VFIELD (t)) = t; + TYPE_ALIGN (t) = TYPE_ALIGN (optr_type); + } + + { + tree name = build_signature_pointer_or_reference_name (to_type, constp, + volatilep, refp); + + /* Build a DECL node for this type, so the debugger has access to it. */ + build_signature_pointer_or_reference_decl (t, name); + } + + CLASSTYPE_GOT_SEMICOLON (t) = 1; + IS_SIGNATURE_POINTER (t) = ! refp; + IS_SIGNATURE_REFERENCE (t) = refp; + SIGNATURE_TYPE (t) = to_type; + + if (m) + { + /* Add this type to the chain of variants of TYPE. + Every type has to be its own TYPE_MAIN_VARIANT. */ + TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m); + TYPE_NEXT_VARIANT (m) = t; + } + else if (refp) + /* Record this type as the reference to TO_TYPE. */ + SIGNATURE_REFERENCE_TO (to_type) = t; + else + /* Record this type as the pointer to TO_TYPE. */ + SIGNATURE_POINTER_TO (to_type) = t; + + /* Lay out the type. This function has many callers that are concerned + with expression-construction, and this simplifies them all. + Also, it guarantees the TYPE_SIZE is permanent if the type is. */ + layout_type (t); + + current_obstack = ambient_obstack; + saveable_obstack = ambient_saveable_obstack; + + /* Ouput debug information for this type. */ + rest_of_type_compilation (t, 1); + + return t; +} + +/* Construct, lay out and return the type of pointers to signature TO_TYPE. */ + +tree +build_signature_pointer_type (to_type, constp, volatilep) + tree to_type; + int constp, volatilep; +{ + return + build_signature_pointer_or_reference_type (to_type, constp, volatilep, 0); +} + +/* Construct, lay out and return the type of pointers to signature TO_TYPE. */ + +tree +build_signature_reference_type (to_type, constp, volatilep) + tree to_type; + int constp, volatilep; +{ + return + build_signature_pointer_or_reference_type (to_type, constp, volatilep, 1); +} + +/* Return the name of the signature table (as an IDENTIFIER_NODE) + for the given signature type SIG_TYPE and rhs type RHS_TYPE. */ + +static tree +get_sigtable_name (sig_type, rhs_type) + tree sig_type, rhs_type; +{ + tree sig_type_id = build_typename_overload (sig_type); + tree rhs_type_id = build_typename_overload (rhs_type); + char *buf = (char *) alloca (sizeof (SIGTABLE_NAME_FORMAT_LONG) + + IDENTIFIER_LENGTH (sig_type_id) + + IDENTIFIER_LENGTH (rhs_type_id) + 20); + char *sig_ptr = IDENTIFIER_POINTER (sig_type_id); + char *rhs_ptr = IDENTIFIER_POINTER (rhs_type_id); + int i, j; + + for (i = 0; sig_ptr[i] == OPERATOR_TYPENAME_FORMAT[i]; i++) + /* do nothing */; + while (sig_ptr[i] >= '0' && sig_ptr[i] <= '9') + i += 1; + + for (j = 0; rhs_ptr[j] == OPERATOR_TYPENAME_FORMAT[j]; j++) + /* do nothing */; + while (rhs_ptr[j] >= '0' && rhs_ptr[j] <= '9') + j += 1; + + if (IS_SIGNATURE (rhs_type)) + sprintf (buf, SIGTABLE_NAME_FORMAT_LONG, sig_ptr+i, rhs_ptr+j, + global_sigtable_name_counter++); + else + sprintf (buf, SIGTABLE_NAME_FORMAT, sig_ptr+i, rhs_ptr+j); + return get_identifier (buf); +} + +/* Build a field decl that points to a signature member function. */ + +static tree +build_member_function_pointer (member) + tree member; +{ + char *namstr = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (member)); + int namlen = IDENTIFIER_LENGTH (DECL_ASSEMBLER_NAME (member)); + char *name; + tree entry; + + name = (char *) alloca (namlen + sizeof (SIGNATURE_FIELD_NAME) + 2); + sprintf (name, SIGNATURE_FIELD_NAME_FORMAT, namstr); + + /* @@ Do we really want to xref signature table fields? */ + GNU_xref_ref (current_function_decl, name); + + entry = build_lang_field_decl (FIELD_DECL, get_identifier (name), + TYPE_MAIN_VARIANT (sigtable_entry_type)); + TREE_CONSTANT (entry) = 1; + TREE_READONLY (entry) = 1; + + /* @@ Do we really want to xref signature table fields? */ + GNU_xref_decl (current_function_decl, entry); + + return entry; +} + +/* For each FUNCTION_DECL in a signature we construct a member function + pointer of the appropriate type. We also need two flags to test + whether the member function pointer points to a virtual function or + to a default implementation. Those flags will be the two lower order + bits of the member function pointer (or the two higher order bits, + based on the configuration). + + The new FIELD_DECLs are appended at the end of the last (and only) + sublist of `list_of_fieldlists.' + + As a side effect, each member function in the signature gets the + `decl.ignored' bit turned on, so we don't output debug info for it. */ + +void +append_signature_fields (list_of_fieldlists) + tree list_of_fieldlists; +{ + tree l, x; + tree last_x = NULL_TREE; + tree mfptr; + tree last_mfptr; + tree mfptr_list = NULL_TREE; + + /* For signatures it should actually be only a list with one element. */ + for (l = list_of_fieldlists; l; l = TREE_CHAIN (l)) + { + for (x = TREE_VALUE (l); x; x = TREE_CHAIN (x)) + { + if (TREE_CODE (x) == FUNCTION_DECL) + { + mfptr = build_member_function_pointer (x); + DECL_MEMFUNC_POINTER_TO (x) = mfptr; + DECL_MEMFUNC_POINTING_TO (mfptr) = x; + DECL_IGNORED_P (x) = 1; + DECL_IN_AGGR_P (mfptr) = 1; + if (! mfptr_list) + mfptr_list = last_mfptr = mfptr; + else + { + TREE_CHAIN (last_mfptr) = mfptr; + last_mfptr = mfptr; + } + } + last_x = x; + } + } + + /* Append the lists. */ + if (last_x && mfptr_list) + { + TREE_CHAIN (last_x) = mfptr_list; + TREE_CHAIN (last_mfptr) = NULL_TREE; + } +} + +/* Compare the types of a signature member function and a class member + function. Returns 1 if the types are in the C++ `<=' relationship. + + If we have a signature pointer/reference as argument or return type + we don't want to do a recursive conformance check. The conformance + check only succeeds if both LHS and RHS refer to the same signature + pointer. Otherwise we need to keep information about parameter types + around at run time to initialize the signature table correctly. */ + +static int +match_method_types (sig_mtype, class_mtype) + tree sig_mtype, class_mtype; +{ + tree sig_return_type = TREE_TYPE (sig_mtype); + tree sig_arg_types = TYPE_ARG_TYPES (sig_mtype); + tree class_return_type = TREE_TYPE (class_mtype); + tree class_arg_types = TYPE_ARG_TYPES (class_mtype); + + /* The return types have to be the same. */ + if (! comptypes (sig_return_type, class_return_type, 1)) + return 0; + + /* Compare the first argument `this.' */ + { + /* Get the type of what the `optr' is pointing to. */ + tree sig_this = + TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_VALUE (sig_arg_types)))); + tree class_this = TREE_VALUE (class_arg_types); + + if (TREE_CODE (class_this) == RECORD_TYPE) /* Is `this' a sig ptr? */ + class_this = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (class_this))); + else + class_this = TREE_TYPE (class_this); + + /* If a signature method's `this' is const or volatile, so has to be + the corresponding class method's `this.' */ + if ((TYPE_READONLY (sig_this) && ! TYPE_READONLY (class_this)) + || (TYPE_VOLATILE (sig_this) && ! TYPE_VOLATILE (class_this))) + return 0; + } + + sig_arg_types = TREE_CHAIN (sig_arg_types); + class_arg_types = TREE_CHAIN (class_arg_types); + + /* The number of arguments and the argument types have to be the same. */ + return compparms (sig_arg_types, class_arg_types, 3); +} + +/* Undo casts of opaque type variables to the RHS types. */ +static void +undo_casts (sig_ty) + tree sig_ty; +{ + tree field = TYPE_FIELDS (sig_ty); + + /* Since all the FIELD_DECLs for the signature table entries are at the end + of the chain (see `append_signature_fields'), we can do it this way. */ + for (; field && TREE_CODE (field) != FIELD_DECL; field = TREE_CHAIN (field)) + if (TYPE_MAIN_VARIANT (TREE_TYPE (field)) == opaque_type_node) + TREE_TYPE (TREE_TYPE (field)) = TREE_TYPE (ptr_type_node); +} + +/* Do the type checking necessary to see whether the `rhs' conforms to + the lhs's `sig_ty'. Depending on the type of `rhs' return a NULL_TREE, + an integer_zero_node, a constructor, or an expression offsetting the + `rhs' signature table. */ + +static tree +build_signature_table_constructor (sig_ty, rhs) + tree sig_ty, rhs; +{ + tree rhstype = TREE_TYPE (rhs); + tree sig_field = TYPE_FIELDS (sig_ty); + tree result = NULL_TREE; + tree first_rhs_field = NULL_TREE; + tree last_rhs_field; + int sig_ptr_p = IS_SIGNATURE (rhstype); + int offset_p = sig_ptr_p; + + rhstype = sig_ptr_p ? rhstype : TREE_TYPE (rhstype); + + if (CLASSTYPE_TAGS (sig_ty)) + { + sorry ("conformance check with signature containing class declarations"); + return error_mark_node; + } + + for (; sig_field; sig_field = TREE_CHAIN (sig_field)) + { + tree basetype_path, baselink, basetypes; + tree sig_method, sig_mname, sig_mtype; + tree rhs_method, tbl_entry; + + if (TREE_CODE (sig_field) == TYPE_DECL) + { + tree sig_field_type = TREE_TYPE (sig_field); + + if (TYPE_MAIN_VARIANT (sig_field_type) == opaque_type_node) + { + /* We've got an opaque type here. */ + tree oty_name = DECL_NAME (sig_field); + tree oty_type = lookup_field (rhstype, oty_name, 1, 1); + + if (oty_type == NULL_TREE || oty_type == error_mark_node) + { + cp_error ("class `%T' does not contain type `%T'", + rhstype, oty_type); + undo_casts (sig_ty); + return error_mark_node; + } + oty_type = TREE_TYPE (oty_type); + + /* Cast `sig_field' to be of type `oty_type'. This will be + undone in `undo_casts' by walking over all the TYPE_DECLs. */ + TREE_TYPE (sig_field_type) = TREE_TYPE (oty_type); + } + /* If we don't have an opaque type, we can ignore the `typedef'. */ + continue; + } + + /* Find the signature method corresponding to `sig_field'. */ + sig_method = DECL_MEMFUNC_POINTING_TO (sig_field); + sig_mname = DECL_NAME (sig_method); + sig_mtype = TREE_TYPE (sig_method); + + basetype_path = TYPE_BINFO (rhstype); + baselink = lookup_fnfields (basetype_path, sig_mname, 0); + if (baselink == NULL_TREE || baselink == error_mark_node) + { + if (! IS_DEFAULT_IMPLEMENTATION (sig_method)) + { + cp_error ("class `%T' does not contain method `%D'", + rhstype, sig_mname); + undo_casts (sig_ty); + return error_mark_node; + } + else + { + /* We use the signature's default implementation. */ + rhs_method = sig_method; + } + } + else + { + /* Find the class method of the correct type. */ + + basetypes = TREE_PURPOSE (baselink); + if (TREE_CODE (basetypes) == TREE_LIST) + basetypes = TREE_VALUE (basetypes); + + rhs_method = TREE_VALUE (baselink); + for (; rhs_method; rhs_method = TREE_CHAIN (rhs_method)) + if (sig_mname == DECL_NAME (rhs_method) + && ! DECL_STATIC_FUNCTION_P (rhs_method) + && match_method_types (sig_mtype, TREE_TYPE (rhs_method))) + break; + + if (rhs_method == NULL_TREE + || (compute_access (basetypes, rhs_method) + != access_public)) + { + error ("class `%s' does not contain a method conforming to `%s'", + TYPE_NAME_STRING (rhstype), + fndecl_as_string (NULL, sig_method, 1)); + undo_casts (sig_ty); + return error_mark_node; + } + } + + if (sig_ptr_p && rhs_method != sig_method) + { + tree rhs_field = DECL_MEMFUNC_POINTER_TO (rhs_method); + + if (first_rhs_field == NULL_TREE) + { + first_rhs_field = rhs_field; + last_rhs_field = rhs_field; + } + else if (TREE_CHAIN (last_rhs_field) == rhs_field) + last_rhs_field = rhs_field; + else + offset_p = 0; + + tbl_entry = build_component_ref (rhs, DECL_NAME (rhs_field), + NULL_TREE, 1); + } + else + { + tree code, offset, pfn; + + if (rhs_method == sig_method) + { + code = integer_two_node; + offset = integer_zero_node; + pfn = build_unary_op (ADDR_EXPR, rhs_method, 0); + TREE_TYPE (pfn) = ptr_type_node; + offset_p = 0; /* we can't offset the rhs sig table */ + } + else if (DECL_VINDEX (rhs_method)) + { + code = integer_one_node; + offset = DECL_VINDEX (rhs_method); + pfn = null_pointer_node; + } + else + { + code = integer_zero_node; + offset = integer_zero_node; + pfn = build_unary_op (ADDR_EXPR, rhs_method, 0); + TREE_TYPE (pfn) = ptr_type_node; + TREE_ADDRESSABLE (rhs_method) = 1; + } + + tbl_entry = tree_cons (NULL_TREE, code, + tree_cons (NULL_TREE, offset, + build_tree_list (NULL_TREE, pfn))); + tbl_entry = build_nt (CONSTRUCTOR, NULL_TREE, tbl_entry); + TREE_HAS_CONSTRUCTOR (tbl_entry) = 1; + TREE_CONSTANT (tbl_entry) = 1; + } + + /* Chain those function address expressions together. */ + if (result) + result = tree_cons (NULL_TREE, tbl_entry, result); + else + result = build_tree_list (NULL_TREE, tbl_entry); + } + + if (result == NULL_TREE) + { + /* The signature was empty, we don't need a signature table. */ + undo_casts (sig_ty); + return NULL_TREE; + } + + if (offset_p) + { + if (first_rhs_field == TYPE_FIELDS (rhstype)) + { + /* The sptr field on the lhs can be copied from the rhs. */ + undo_casts (sig_ty); + return integer_zero_node; + } + else + { + /* The sptr field on the lhs will point into the rhs sigtable. */ + undo_casts (sig_ty); + return build_component_ref (rhs, DECL_NAME (first_rhs_field), + NULL_TREE, 0); + } + } + + /* We need to construct a new signature table. */ + result = build_nt (CONSTRUCTOR, NULL_TREE, nreverse (result)); + TREE_HAS_CONSTRUCTOR (result) = 1; + TREE_CONSTANT (result) = !sig_ptr_p; + + undo_casts (sig_ty); + return result; +} + +/* Build a signature table declaration and initialize it or return an + existing one if we built one already. If we don't get a constructor + as initialization expression, we don't need a new signature table + variable and just hand back the init expression. + + The declaration processing is done by hand instead of using `finish_decl' + so that we can make signature pointers global variables instead of + static ones. */ + +static tree +build_sigtable (sig_type, rhs_type, init_from) + tree sig_type, rhs_type, init_from; +{ + tree name = NULL_TREE; + tree decl = NULL_TREE; + tree init_expr; + + push_obstacks_nochange (); + end_temporary_allocation (); + + if (! IS_SIGNATURE (rhs_type)) + { + name = get_sigtable_name (sig_type, rhs_type); + decl = IDENTIFIER_GLOBAL_VALUE (name); + } + if (decl == NULL_TREE) + { + tree init; + + /* We allow only one signature table to be generated for signatures + with opaque types. Otherwise we create a loophole in the type + system since we could cast data from one classes implementation + of the opaque type to that of another class. */ + if (SIGNATURE_HAS_OPAQUE_TYPEDECLS (sig_type) + && SIGTABLE_HAS_BEEN_GENERATED (sig_type)) + { + error ("signature with opaque type implemented by multiple classes"); + return error_mark_node; + } + SIGTABLE_HAS_BEEN_GENERATED (sig_type) = 1; + + init_expr = build_signature_table_constructor (sig_type, init_from); + if (init_expr == NULL_TREE || TREE_CODE (init_expr) != CONSTRUCTOR) + return init_expr; + + if (name == NULL_TREE) + name = get_sigtable_name (sig_type, rhs_type); + { + tree context = current_function_decl; + + /* Make the signature table global, not just static in whichever + function a signature pointer/ref is used for the first time. */ + current_function_decl = NULL_TREE; + decl = pushdecl_top_level (build_decl (VAR_DECL, name, sig_type)); + current_function_decl = context; + } + IDENTIFIER_GLOBAL_VALUE (name) = decl; + store_init_value (decl, init_expr); + if (IS_SIGNATURE (rhs_type)) + { + init = DECL_INITIAL (decl); + DECL_INITIAL (decl) = error_mark_node; + } + + DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node), + DECL_ALIGN (decl)); +#if 0 + /* GDB-4.7 doesn't find the initialization value of a signature table + when it is constant. */ + TREE_READONLY (decl) = 1; +#endif + TREE_STATIC (decl) = 1; + TREE_USED (decl) = 1; + + make_decl_rtl (decl, NULL, 1); + if (IS_SIGNATURE (rhs_type)) + expand_static_init (decl, init); + } + + pop_obstacks (); + + return decl; +} + +/* Create a constructor or modify expression if the LHS of an assignment + is a signature pointer or a signature reference. If LHS is a record + type node, we build a constructor, otherwise a compound expression. */ + +tree +build_signature_pointer_constructor (lhs, rhs) + tree lhs, rhs; +{ + register struct obstack *ambient_obstack = current_obstack; + register struct obstack *ambient_saveable_obstack = saveable_obstack; + int initp = (TREE_CODE (lhs) == RECORD_TYPE); + tree lhstype = initp ? lhs : TREE_TYPE (lhs); + tree rhstype = TREE_TYPE (rhs); + tree sig_ty = SIGNATURE_TYPE (lhstype); + tree sig_tbl, sptr_expr, optr_expr, vptr_expr; + tree result; + + if (! ((TREE_CODE (rhstype) == POINTER_TYPE + && TREE_CODE (TREE_TYPE (rhstype)) == RECORD_TYPE) + || (TYPE_LANG_SPECIFIC (rhstype) && + (IS_SIGNATURE_POINTER (rhstype) + || IS_SIGNATURE_REFERENCE (rhstype))))) + { + error ("invalid assignment to signature pointer or reference"); + return error_mark_node; + } + + if (TYPE_SIZE (sig_ty) == NULL_TREE) + { + cp_error ("undefined signature `%T' used in signature %s declaration", + sig_ty, + IS_SIGNATURE_POINTER (lhstype) ? "pointer" : "reference"); + return error_mark_node; + } + + /* If SIG_TY is permanent, make the signature table constructor and + the signature pointer/reference constructor permanent too. */ + if (TREE_PERMANENT (sig_ty)) + { + current_obstack = &permanent_obstack; + saveable_obstack = &permanent_obstack; + } + + if (TYPE_LANG_SPECIFIC (rhstype) && + (IS_SIGNATURE_POINTER (rhstype) || IS_SIGNATURE_REFERENCE (rhstype))) + { + if (SIGNATURE_TYPE (rhstype) == sig_ty) + { + /* LHS and RHS are signature pointers/refs of the same signature. */ + optr_expr = build_optr_ref (rhs); + sptr_expr = build_sptr_ref (rhs); + vptr_expr = build_vptr_ref (rhs); + } + else + { + /* We need to create a new signature table and copy + elements from the rhs signature table. */ + tree rhs_sptr_ref = build_sptr_ref (rhs); + tree rhs_tbl = build1 (INDIRECT_REF, SIGNATURE_TYPE (rhstype), + rhs_sptr_ref); + + sig_tbl = build_sigtable (sig_ty, SIGNATURE_TYPE (rhstype), rhs_tbl); + if (sig_tbl == error_mark_node) + return error_mark_node; + + optr_expr = build_optr_ref (rhs); + if (sig_tbl == NULL_TREE) + /* The signature was empty. The signature pointer is + pretty useless, but the user has been warned. */ + sptr_expr = copy_node (null_pointer_node); + else if (sig_tbl == integer_zero_node) + sptr_expr = rhs_sptr_ref; + else + sptr_expr = build_unary_op (ADDR_EXPR, sig_tbl, 0); + TREE_TYPE (sptr_expr) = build_pointer_type (sig_ty); + vptr_expr = build_vptr_ref (rhs); + } + } + else + { + tree rhs_vptr; + + if (TYPE_USES_COMPLEX_INHERITANCE (TREE_TYPE (rhstype))) + { + sorry ("class with multiple inheritance as implementation of signature"); + return error_mark_node; + } + + sig_tbl = build_sigtable (sig_ty, TREE_TYPE (rhstype), rhs); + if (sig_tbl == error_mark_node) + return error_mark_node; + + optr_expr = rhs; + if (sig_tbl == NULL_TREE) + /* The signature was empty. The signature pointer is + pretty useless, but the user has been warned. */ + { + sptr_expr = copy_node (null_pointer_node); + TREE_TYPE (sptr_expr) = build_pointer_type (sig_ty); + } + else + sptr_expr = build_unary_op (ADDR_EXPR, sig_tbl, 0); + if (CLASSTYPE_VFIELD (TREE_TYPE (rhstype))) + { + rhs_vptr = DECL_NAME (CLASSTYPE_VFIELD (TREE_TYPE (rhstype))); + vptr_expr = build_component_ref (build_indirect_ref (rhs, 0), + rhs_vptr, NULL_TREE, 0); + } + else + vptr_expr = copy_node (null_pointer_node); + TREE_TYPE (vptr_expr) = build_pointer_type (vtbl_type_node); + } + + if (initp) + { + result = tree_cons (NULL_TREE, optr_expr, + tree_cons (NULL_TREE, sptr_expr, + build_tree_list (NULL_TREE, vptr_expr))); + result = build_nt (CONSTRUCTOR, NULL_TREE, result); + TREE_HAS_CONSTRUCTOR (result) = 1; + result = digest_init (lhstype, result, 0); + } + else + { + if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)) + readonly_error (lhs, "assignment", 0); + + optr_expr = build_modify_expr (build_optr_ref (lhs), NOP_EXPR, + optr_expr); + sptr_expr = build_modify_expr (build_sptr_ref (lhs), NOP_EXPR, + sptr_expr); + vptr_expr = build_modify_expr (build_vptr_ref (lhs), NOP_EXPR, + vptr_expr); + + result = tree_cons (NULL_TREE, optr_expr, + tree_cons (NULL_TREE, sptr_expr, + tree_cons (NULL_TREE, vptr_expr, + build_tree_list (NULL_TREE, + lhs)))); + result = build_compound_expr (result); + } + + current_obstack = ambient_obstack; + saveable_obstack = ambient_saveable_obstack; + return result; +} + +/* Build a temporary variable declaration for the instance of a signature + member function call if it isn't a declaration node already. Simply + using a SAVE_EXPR doesn't work since we need `this' in both branches + of a conditional expression. */ + +static tree +save_this (instance) + tree instance; +{ + tree decl; + + if (TREE_CODE_CLASS (TREE_CODE (instance)) == 'd') + decl = instance; + else + { + decl = build_decl (VAR_DECL, NULL_TREE, TREE_TYPE (instance)); + DECL_REGISTER (decl) = 1; + layout_decl (decl, 0); + expand_decl (decl); + } + + return decl; +} + +/* Build a signature member function call. Looks up the signature table + entry corresponding to FUNCTION. Depending on the value of the CODE + field, either call the function in PFN directly, or use OFFSET to + index INSTANCE's virtual function table. */ + +tree +build_signature_method_call (basetype, instance, function, parms) + tree basetype, instance, function, parms; +{ + tree saved_instance = save_this (instance); /* Create temp for `this'. */ + tree signature_tbl_ptr = build_sptr_ref (saved_instance); + tree sig_field_name = DECL_NAME (DECL_MEMFUNC_POINTER_TO (function)); + tree basetype_path = TYPE_BINFO (basetype); + tree tbl_entry = build_component_ref (build1 (INDIRECT_REF, basetype, + signature_tbl_ptr), + sig_field_name, basetype_path, 1); + tree code, offset, pfn, vfn; + tree deflt_call = NULL_TREE, direct_call, virtual_call, result; + + code = build_component_ref (tbl_entry, get_identifier (SIGTABLE_CODE_NAME), + NULL_TREE, 1); + offset = build_component_ref (tbl_entry, + get_identifier (SIGTABLE_OFFSET_NAME), + NULL_TREE, 1); + pfn = build_component_ref (tbl_entry, get_identifier (SIGTABLE_PFN_NAME), + NULL_TREE, 1); + TREE_TYPE (pfn) = build_pointer_type (TREE_TYPE (function)); + + if (IS_DEFAULT_IMPLEMENTATION (function)) + { + pfn = save_expr (pfn); + deflt_call = build_function_call (pfn, + tree_cons (NULL_TREE, saved_instance, + TREE_CHAIN (parms))); + } + + { + /* Cast the signature method to have `this' of a normal pointer type. */ + tree old_this = TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (TREE_TYPE (pfn)))); + + TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (TREE_TYPE (pfn)))) = + build_type_variant (TYPE_POINTER_TO (basetype), + TYPE_READONLY (old_this), + TYPE_VOLATILE (old_this)); + + direct_call = build_function_call (pfn, parms); + + vfn = build_vfn_ref (&TREE_VALUE (parms), saved_instance, offset); + TREE_TYPE (vfn) = build_pointer_type (TREE_TYPE (function)); + virtual_call = build_function_call (vfn, parms); + + /* Undo the cast, make `this' a signature pointer again. */ + TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (TREE_TYPE (pfn)))) = old_this; + } + + /* Once the function was found, there should be no reason why we + couldn't build the member function pointer call. */ + if (!direct_call || direct_call == error_mark_node + || !virtual_call || virtual_call == error_mark_node + || (IS_DEFAULT_IMPLEMENTATION (function) + && (!deflt_call || deflt_call == error_mark_node))) + { + compiler_error ("cannot build call of signature member function `%s'", + fndecl_as_string (NULL, function, 1)); + return error_mark_node; + } + + if (IS_DEFAULT_IMPLEMENTATION (function)) + { + tree test = build_binary_op_nodefault (EQ_EXPR, code, integer_one_node, + EQ_EXPR); + result = build_conditional_expr (code, + build_conditional_expr (test, + virtual_call, + deflt_call), + direct_call); + } + else + result = build_conditional_expr (code, virtual_call, direct_call); + + /* If we created a temporary variable for `this', initialize it first. */ + if (instance != saved_instance) + result = build (COMPOUND_EXPR, TREE_TYPE (result), + build_modify_expr (saved_instance, NOP_EXPR, instance), + result); + + return result; +} + +/* Create a COMPONENT_REF expression for referencing the OPTR field + of a signature pointer or reference. */ + +tree +build_optr_ref (instance) + tree instance; +{ + tree field = get_identifier (SIGNATURE_OPTR_NAME); + + return build_component_ref (instance, field, NULL_TREE, 1); +} + +/* Create a COMPONENT_REF expression for referencing the SPTR field + of a signature pointer or reference. */ + +tree +build_sptr_ref (instance) + tree instance; +{ + tree field = get_identifier (SIGNATURE_SPTR_NAME); + + return build_component_ref (instance, field, NULL_TREE, 1); +} + +/* Create a COMPONENT_REF expression for referencing the VPTR field + of a signature pointer or reference. */ + +tree +build_vptr_ref (instance) + tree instance; +{ + tree field = get_identifier (SIGNATURE_VPTR_NAME); + + return build_component_ref (instance, field, NULL_TREE, 1); +} |
