/* Language-level data type conversion for GNU C++.
- Copyright (C) 1987, 88, 92, 93, 94, 95, 1996 Free Software Foundation, Inc.
+ Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
+ 1999, 2000 Free Software Foundation, Inc.
Hacked by Michael Tiemann (tiemann@cygnus.com)
This file is part of GNU CC.
but what kind of conversions it does will depend on the language. */
#include "config.h"
-#include <stdio.h>
+#include "system.h"
#include "tree.h"
#include "flags.h"
#include "cp-tree.h"
-#include "class.h"
#include "convert.h"
+#include "toplev.h"
+#include "decl.h"
-#ifdef HAVE_STDLIB_H
-#include <stdlib.h>
-#endif
-
-extern tree static_aggregates;
-
-static tree build_thunk PROTO((tree, tree));
-static tree convert_fn_ptr PROTO((tree, tree));
-static tree cp_convert_to_pointer PROTO((tree, tree));
-static tree convert_to_pointer_force PROTO((tree, tree));
-static tree build_up_reference PROTO((tree, tree, int, int));
-static tree build_type_conversion_1 PROTO((tree, tree, tree, tree,
- int));
+static tree cp_convert_to_pointer PARAMS ((tree, tree, int));
+static tree convert_to_pointer_force PARAMS ((tree, tree));
+static tree build_up_reference PARAMS ((tree, tree, int, tree));
+static void warn_ref_binding PARAMS ((tree, tree, tree));
/* Change of width--truncation and extension of integers or reals--
is represented with NOP_EXPR. Proper functioning of many things
\f
/* Subroutines of `convert'. */
-/* Build a thunk. What it is, is an entry point that when called will
- adjust the this pointer (the first argument) by offset, and then
- goto the real address of the function given by REAL_ADDR that we
- would like called. What we return is the address of the thunk. */
-
-static tree
-build_thunk (offset, real_addr)
- tree offset, real_addr;
-{
- if (TREE_CODE (real_addr) != ADDR_EXPR
- || TREE_CODE (TREE_OPERAND (real_addr, 0)) != FUNCTION_DECL)
- {
- sorry ("MI pointer to member conversion too complex");
- return error_mark_node;
- }
- sorry ("MI pointer to member conversion too complex");
- return error_mark_node;
-}
-
-/* Convert a `pointer to member' (POINTER_TYPE to METHOD_TYPE) into
- another `pointer to method'. This may involved the creation of
- a thunk to handle the this offset calculation. */
-
-static tree
-convert_fn_ptr (type, expr)
- tree type, expr;
-{
-#if 0 /* We don't use thunks for pmfs. */
- if (flag_vtable_thunks)
- {
- tree intype = TREE_TYPE (expr);
- tree binfo = get_binfo (TYPE_METHOD_BASETYPE (TREE_TYPE (intype)),
- TYPE_METHOD_BASETYPE (TREE_TYPE (type)), 1);
- if (binfo == error_mark_node)
- {
- error (" in pointer to member conversion");
- return error_mark_node;
- }
- if (binfo == NULL_TREE)
- {
- /* ARM 4.8 restriction. */
- error ("invalid pointer to member conversion");
- return error_mark_node;
- }
-
- if (BINFO_OFFSET_ZEROP (binfo))
- return build1 (NOP_EXPR, type, expr);
- return build1 (NOP_EXPR, type, build_thunk (BINFO_OFFSET (binfo), expr));
- }
- else
-#endif
- return build_ptrmemfunc (type, expr, 1);
-}
-
/* if converting pointer to pointer
if dealing with classes, check for derived->base or vice versa
else if dealing with method pointers, delegate
else convert blindly
else if converting class, pass off to build_type_conversion
- else try C-style pointer conversion */
+ else try C-style pointer conversion. If FORCE is true then allow
+ conversions via virtual bases (these are permitted by reinterpret_cast,
+ but not static_cast). */
static tree
-cp_convert_to_pointer (type, expr)
+cp_convert_to_pointer (type, expr, force)
tree type, expr;
+ int force;
{
register tree intype = TREE_TYPE (expr);
register enum tree_code form;
+ tree rval;
if (IS_AGGR_TYPE (intype))
{
- tree rval;
-
intype = complete_type (intype);
- if (TYPE_SIZE (intype) == NULL_TREE)
+ if (!COMPLETE_TYPE_P (intype))
{
cp_error ("can't convert from incomplete type `%T' to `%T'",
intype, type);
return error_mark_node;
}
- rval = build_type_conversion (CONVERT_EXPR, type, expr, 1);
+ rval = build_type_conversion (type, expr, 1);
if (rval)
{
if (rval == error_mark_node)
}
}
- if (TYPE_PTRMEMFUNC_P (type))
- type = TYPE_PTRMEMFUNC_FN_TYPE (type);
-
/* Handle anachronistic conversions from (::*)() to cv void* or (*)(). */
if (TREE_CODE (type) == POINTER_TYPE
&& (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
- || TYPE_MAIN_VARIANT (TREE_TYPE (type)) == void_type_node))
+ || VOID_TYPE_P (TREE_TYPE (type))))
{
/* Allow an implicit this pointer for pointer to member
functions. */
if (TYPE_PTRMEMFUNC_P (intype))
{
- tree decl, basebinfo;
tree fntype = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (intype));
- tree t = TYPE_METHOD_BASETYPE (fntype);
-
- if (current_class_type == 0
- || get_base_distance (t, current_class_type, 0, &basebinfo)
- == -1)
- {
- decl = build1 (NOP_EXPR, t, error_mark_node);
- }
- else if (current_class_ptr == 0)
- decl = build1 (NOP_EXPR, t, error_mark_node);
- else
- decl = current_class_ref;
-
+ tree decl = maybe_dummy_object (TYPE_METHOD_BASETYPE (fntype), 0);
expr = build (OFFSET_REF, fntype, decl, expr);
}
intype = TREE_TYPE (expr);
}
- if (TYPE_PTRMEMFUNC_P (intype))
- intype = TYPE_PTRMEMFUNC_FN_TYPE (intype);
-
form = TREE_CODE (intype);
- if (form == POINTER_TYPE || form == REFERENCE_TYPE)
+ if (POINTER_TYPE_P (intype))
{
intype = TYPE_MAIN_VARIANT (intype);
if (TYPE_MAIN_VARIANT (type) != intype
+ && TREE_CODE (type) == POINTER_TYPE
&& TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE
&& IS_AGGR_TYPE (TREE_TYPE (type))
&& IS_AGGR_TYPE (TREE_TYPE (intype))
- && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE)
+ && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE
+ /* If EXPR is NULL, then we don't need to do any arithmetic
+ to convert it:
+
+ [conv.ptr]
+
+ The null pointer value is converted to the null pointer
+ value of the destination type. */
+ && !integer_zerop (expr))
{
enum tree_code code = PLUS_EXPR;
tree binfo = get_binfo (TREE_TYPE (type), TREE_TYPE (intype), 1);
tree path;
if (code == PLUS_EXPR)
- get_base_distance (TREE_TYPE (type), TREE_TYPE (intype), 0, &path);
+ get_base_distance (TREE_TYPE (type), TREE_TYPE (intype),
+ 0, &path);
else
- get_base_distance (TREE_TYPE (intype), TREE_TYPE (type), 0, &path);
+ get_base_distance (TREE_TYPE (intype), TREE_TYPE (type),
+ 0, &path);
return build_vbase_path (code, type, expr, path, 0);
}
}
}
- if (TREE_CODE (TREE_TYPE (intype)) == METHOD_TYPE
- && TREE_CODE (type) == POINTER_TYPE
- && TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE)
- return convert_fn_ptr (type, expr);
- if (TREE_CODE (TREE_TYPE (type)) == OFFSET_TYPE
- && TREE_CODE (TREE_TYPE (intype)) == OFFSET_TYPE)
+ if (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
{
- tree b1 = TYPE_OFFSET_BASETYPE (TREE_TYPE (type));
- tree b2 = TYPE_OFFSET_BASETYPE (TREE_TYPE (intype));
- tree binfo = get_binfo (b2, b1, 1);
- enum tree_code code = PLUS_EXPR;
+ tree b1;
+ tree b2;
+ tree binfo;
+ tree virt_binfo;
+ enum tree_code code;
+
+ b1 = TYPE_OFFSET_BASETYPE (TREE_TYPE (type));
+ b2 = TYPE_OFFSET_BASETYPE (TREE_TYPE (intype));
+ binfo = get_binfo (b2, b1, 1);
if (binfo == NULL_TREE)
{
binfo = get_binfo (b1, b2, 1);
code = MINUS_EXPR;
}
+ else
+ code = PLUS_EXPR;
if (binfo == error_mark_node)
return error_mark_node;
- if (binfo && ! TREE_VIA_VIRTUAL (binfo))
- expr = size_binop (code, expr, BINFO_OFFSET (binfo));
- }
- if (TREE_CODE (TREE_TYPE (intype)) == METHOD_TYPE
- || (TREE_CODE (type) == POINTER_TYPE
- && TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE))
+ virt_binfo = binfo_from_vbase (binfo);
+ if (virt_binfo)
+ {
+ if (force)
+ cp_warning ("pointer to member cast via virtual base `%T' of `%T'",
+ BINFO_TYPE (virt_binfo),
+ BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)));
+ else
+ {
+ cp_error ("pointer to member cast via virtual base `%T' of `%T'",
+ BINFO_TYPE (virt_binfo),
+ BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)));
+ return error_mark_node;
+ }
+ /* This is a reinterpret cast, whose result is unspecified.
+ We choose to do nothing. */
+ return build1 (NOP_EXPR, type, expr);
+ }
+
+ if (TREE_CODE (expr) == PTRMEM_CST)
+ expr = cplus_expand_constant (expr);
+
+ if (binfo)
+ expr = size_binop (code, convert (sizetype, expr),
+ BINFO_OFFSET (binfo));
+ }
+ else if (TYPE_PTRMEMFUNC_P (type))
{
cp_error ("cannot convert `%E' from type `%T' to type `%T'",
expr, intype, type);
return error_mark_node;
}
- return build1 (NOP_EXPR, type, expr);
+ rval = build1 (NOP_EXPR, type, expr);
+ TREE_CONSTANT (rval) = TREE_CONSTANT (expr);
+ return rval;
+ }
+ else if (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype))
+ return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0);
+ else if (TYPE_PTRMEMFUNC_P (intype))
+ {
+ cp_error ("cannot convert `%E' from type `%T' to type `%T'",
+ expr, intype, type);
+ return error_mark_node;
}
my_friendly_assert (form != OFFSET_TYPE, 186);
- if (TYPE_LANG_SPECIFIC (intype)
- && (IS_SIGNATURE_POINTER (intype) || IS_SIGNATURE_REFERENCE (intype)))
- return convert_to_pointer (type, build_optr_ref (expr));
-
if (integer_zerop (expr))
{
- if (TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE)
- return build_ptrmemfunc (type, expr, 0);
- expr = build_int_2 (0, 0);
+ if (TYPE_PTRMEMFUNC_P (type))
+ return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0);
+
+ if (TYPE_PTRMEM_P (type))
+ /* A NULL pointer-to-member is represented by -1, not by
+ zero. */
+ expr = build_int_2 (-1, -1);
+ else
+ expr = build_int_2 (0, 0);
TREE_TYPE (expr) = type;
return expr;
}
if (INTEGRAL_CODE_P (form))
{
- if (type_precision (intype) == POINTER_SIZE)
+ if (TYPE_PRECISION (intype) == POINTER_SIZE)
return build1 (CONVERT_EXPR, type, expr);
expr = cp_convert (type_for_size (POINTER_SIZE, 0), expr);
/* Modes may be different but sizes should be the same. */
return convert_to_pointer (type, expr);
}
+ if (type_unknown_p (expr))
+ return instantiate_type (type, expr, itf_complain);
+
cp_error ("cannot convert `%E' from type `%T' to type `%T'",
expr, intype, type);
return error_mark_node;
return expr;
}
- /* Convert signature pointer/reference to `void *' first. */
- if (form == RECORD_TYPE
- && (IS_SIGNATURE_POINTER (intype) || IS_SIGNATURE_REFERENCE (intype)))
- {
- expr = build_optr_ref (expr);
- intype = TREE_TYPE (expr);
- form = TREE_CODE (intype);
- }
-
if (form == POINTER_TYPE)
{
intype = TYPE_MAIN_VARIANT (intype);
TREE_TYPE (intype), 0, &path);
if (distance == -2)
{
- ambig:
- cp_error ("type `%T' is ambiguous baseclass of `%s'",
+ cp_error ("type `%T' is ambiguous base of `%T'",
TREE_TYPE (type),
- TYPE_NAME_STRING (TREE_TYPE (intype)));
+ TREE_TYPE (intype));
return error_mark_node;
}
if (distance == -1)
distance = get_base_distance (TREE_TYPE (intype),
TREE_TYPE (type), 0, &path);
if (distance == -2)
- goto ambig;
+ {
+ cp_error ("type `%T' is ambiguous base of `%T'",
+ TREE_TYPE (intype),
+ TREE_TYPE (type));
+ return error_mark_node;
+ }
if (distance < 0)
/* Doesn't need any special help from us. */
return build1 (NOP_EXPR, type, expr);
}
}
- return cp_convert_to_pointer (type, expr);
+ return cp_convert_to_pointer (type, expr, 1);
}
/* We are passing something to a function which requires a reference.
value we have to begin with is in ARG.
FLAGS controls how we manage access checking.
- DIRECT_BIND in FLAGS controls how any temporaries are generated. */
+ DIRECT_BIND in FLAGS controls how any temporaries are generated.
+ If DIRECT_BIND is set, DECL is the reference we're binding to. */
static tree
-build_up_reference (type, arg, flags, checkconst)
- tree type, arg;
- int flags, checkconst;
+build_up_reference (type, arg, flags, decl)
+ tree type, arg, decl;
+ int flags;
{
tree rval;
tree argtype = TREE_TYPE (arg);
tree target_type = TREE_TYPE (type);
+ tree stmt_expr = NULL_TREE;
my_friendly_assert (TREE_CODE (type) == REFERENCE_TYPE, 187);
if ((flags & DIRECT_BIND) && ! real_lvalue_p (arg))
{
+ /* Create a new temporary variable. We can't just use a TARGET_EXPR
+ here because it needs to live as long as DECL. */
tree targ = arg;
- if (toplevel_bindings_p ())
- arg = get_temp_name (argtype, 1);
+
+ arg = build_decl (VAR_DECL, NULL_TREE, argtype);
+ DECL_ARTIFICIAL (arg) = 1;
+ TREE_USED (arg) = 1;
+ TREE_STATIC (arg) = TREE_STATIC (decl);
+
+ if (TREE_STATIC (decl))
+ {
+ /* Namespace-scope or local static; give it a mangled name. */
+ tree name = mangle_ref_init_variable (decl);
+ DECL_NAME (arg) = name;
+ SET_DECL_ASSEMBLER_NAME (arg, name);
+ arg = pushdecl_top_level (arg);
+ }
else
{
- arg = pushdecl (build_decl (VAR_DECL, NULL_TREE, argtype));
- DECL_ARTIFICIAL (arg) = 1;
+ /* Automatic; make sure we handle the cleanup properly. */
+ maybe_push_cleanup_level (argtype);
+ arg = pushdecl (arg);
}
+
+ /* Process the initializer for the declaration. */
DECL_INITIAL (arg) = targ;
- cp_finish_decl (arg, targ, NULL_TREE, 0, LOOKUP_ONLYCONVERTING);
+ cp_finish_decl (arg, targ, NULL_TREE,
+ LOOKUP_ONLYCONVERTING|DIRECT_BIND);
}
else if (!(flags & DIRECT_BIND) && ! lvalue_p (arg))
- {
- tree slot = build_decl (VAR_DECL, NULL_TREE, argtype);
- arg = build (TARGET_EXPR, argtype, slot, arg, NULL_TREE, NULL_TREE);
- TREE_SIDE_EFFECTS (arg) = 1;
- }
+ return get_target_expr (arg);
- /* If we had a way to wrap this up, and say, if we ever needed it's
+ /* If we had a way to wrap this up, and say, if we ever needed its
address, transform all occurrences of the register, into a memory
reference we could win better. */
rval = build_unary_op (ADDR_EXPR, arg, 1);
+ if (rval == error_mark_node)
+ return error_mark_node;
+
if ((flags & LOOKUP_PROTECT)
&& TYPE_MAIN_VARIANT (argtype) != TYPE_MAIN_VARIANT (target_type)
&& IS_AGGR_TYPE (argtype)
= convert_to_pointer_force (build_pointer_type (target_type), rval);
rval = build1 (NOP_EXPR, type, rval);
TREE_CONSTANT (rval) = TREE_CONSTANT (TREE_OPERAND (rval, 0));
+
+ /* If we created and initialized a new temporary variable, add the
+ representation of that initialization to the RVAL. */
+ if (stmt_expr)
+ rval = build (COMPOUND_EXPR, TREE_TYPE (rval), stmt_expr, rval);
+
+ /* And return the result. */
return rval;
}
+/* Subroutine of convert_to_reference. REFTYPE is the target reference type.
+ INTYPE is the original rvalue type and DECL is an optional _DECL node
+ for diagnostics.
+
+ [dcl.init.ref] says that if an rvalue is used to
+ initialize a reference, then the reference must be to a
+ non-volatile const type. */
+
+static void
+warn_ref_binding (reftype, intype, decl)
+ tree reftype, intype, decl;
+{
+ tree ttl = TREE_TYPE (reftype);
+
+ if (!CP_TYPE_CONST_NON_VOLATILE_P (ttl))
+ {
+ const char *msg;
+
+ if (CP_TYPE_VOLATILE_P (ttl) && decl)
+ msg = "initialization of volatile reference type `%#T' from rvalue of type `%T'";
+ else if (CP_TYPE_VOLATILE_P (ttl))
+ msg = "conversion to volatile reference type `%#T' from rvalue of type `%T'";
+ else if (decl)
+ msg = "initialization of non-const reference type `%#T' from rvalue of type `%T'";
+ else
+ msg = "conversion to non-const reference type `%#T' from rvalue of type `%T'";
+
+ cp_pedwarn (msg, reftype, intype);
+ }
+}
+
/* For C++: Only need to do one-level references, but cannot
get tripped up on signed/unsigned differences.
tree rval_as_conversion = NULL_TREE;
int i;
+ if (TREE_CODE (type) == FUNCTION_TYPE && intype == unknown_type_node)
+ {
+ expr = instantiate_type (type, expr,
+ (flags & LOOKUP_COMPLAIN)
+ ? itf_complain : itf_none);
+ if (expr == error_mark_node)
+ return error_mark_node;
+
+ intype = TREE_TYPE (expr);
+ }
+
if (TREE_CODE (intype) == REFERENCE_TYPE)
my_friendly_abort (364);
{
/* Look for a user-defined conversion to lvalue that we can use. */
- if (flag_ansi_overloading)
- rval_as_conversion
- = build_type_conversion (CONVERT_EXPR, reftype, expr, 1);
- else
- rval_as_conversion = build_type_conversion (CONVERT_EXPR, type, expr, 1);
+ rval_as_conversion
+ = build_type_conversion (reftype, expr, 1);
if (rval_as_conversion && rval_as_conversion != error_mark_node
&& real_lvalue_p (rval_as_conversion))
if (flags & LOOKUP_COMPLAIN)
{
tree ttl = TREE_TYPE (reftype);
- tree ttr;
-
- {
- int r = TREE_READONLY (expr);
- int v = TREE_THIS_VOLATILE (expr);
- ttr = cp_build_type_variant (TREE_TYPE (expr), r, v);
- }
+ tree ttr = lvalue_type (expr);
- if (! real_lvalue_p (expr) && ! TYPE_READONLY (ttl))
- {
- if (decl)
- /* Ensure semantics of [dcl.init.ref] */
- cp_pedwarn ("initialization of non-const reference `%#T' from rvalue `%T'",
- reftype, intype);
- else
- cp_pedwarn ("conversion to non-const `%T' from rvalue `%T'",
- reftype, intype);
- }
- else if (! (convtype & CONV_CONST))
- {
- if (! TYPE_READONLY (ttl) && TYPE_READONLY (ttr))
- cp_pedwarn ("conversion from `%T' to `%T' discards const",
- ttr, reftype);
- else if (! TYPE_VOLATILE (ttl) && TYPE_VOLATILE (ttr))
- cp_pedwarn ("conversion from `%T' to `%T' discards volatile",
- ttr, reftype);
- }
+ if (! real_lvalue_p (expr))
+ warn_ref_binding (reftype, intype, decl);
+
+ if (! (convtype & CONV_CONST)
+ && !at_least_as_qualified_p (ttl, ttr))
+ cp_pedwarn ("conversion from `%T' to `%T' discards qualifiers",
+ ttr, reftype);
}
- return build_up_reference (reftype, expr, flags,
- ! (convtype & CONV_CONST));
+ return build_up_reference (reftype, expr, flags, decl);
}
else if ((convtype & CONV_REINTERPRET) && lvalue_p (expr))
{
/* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they
meant. */
if (TREE_CODE (intype) == POINTER_TYPE
- && (comptypes (TREE_TYPE (intype), type, -1)))
+ && (comptypes (TREE_TYPE (intype), type,
+ COMPARE_BASE | COMPARE_RELAXED )))
cp_warning ("casting `%T' to `%T' does not dereference pointer",
intype, reftype);
rval = build_unary_op (ADDR_EXPR, expr, 0);
if (rval != error_mark_node)
- rval = convert_force (build_pointer_type (TREE_TYPE (reftype)), rval, 0);
+ rval = convert_force (build_pointer_type (TREE_TYPE (reftype)),
+ rval, 0);
if (rval != error_mark_node)
rval = build1 (NOP_EXPR, reftype, rval);
}
- else if (flag_ansi_overloading)
+ else
{
rval = convert_for_initialization (NULL_TREE, type, expr, flags,
"converting", 0, 0);
- if (rval == error_mark_node)
- return error_mark_node;
- rval = build_up_reference (reftype, rval, flags, 1);
-
- if (rval && ! TYPE_READONLY (TREE_TYPE (reftype)))
- cp_pedwarn ("initializing non-const `%T' with `%T' will use a temporary",
- reftype, intype);
- }
- else
- {
- tree rval_as_ctor = NULL_TREE;
-
- if (rval_as_conversion)
- {
- if (rval_as_conversion == error_mark_node)
- {
- cp_error ("conversion from `%T' to `%T' is ambiguous",
- intype, reftype);
- return error_mark_node;
- }
- rval_as_conversion = build_up_reference (reftype, rval_as_conversion,
- flags, 1);
- }
-
- /* Definitely need to go through a constructor here. */
- if (TYPE_HAS_CONSTRUCTOR (type)
- && ! CLASSTYPE_ABSTRACT_VIRTUALS (type)
- && (rval = build_method_call
- (NULL_TREE, ctor_identifier,
- build_expr_list (NULL_TREE, expr), TYPE_BINFO (type),
- LOOKUP_NO_CONVERSION|LOOKUP_SPECULATIVELY
- | LOOKUP_ONLYCONVERTING)))
- {
- tree init;
-
- if (toplevel_bindings_p ())
- {
- tree t = get_temp_name (type, toplevel_bindings_p ());
- init = build_method_call (t, ctor_identifier,
- build_expr_list (NULL_TREE, expr),
- TYPE_BINFO (type),
- LOOKUP_NORMAL|LOOKUP_NO_CONVERSION
- | LOOKUP_ONLYCONVERTING);
-
- if (init == error_mark_node)
- return error_mark_node;
-
- make_decl_rtl (t, NULL_PTR, 1);
- static_aggregates = perm_tree_cons (expr, t, static_aggregates);
- rval = build_unary_op (ADDR_EXPR, t, 0);
- }
- else
- {
- init = build_method_call (NULL_TREE, ctor_identifier,
- build_expr_list (NULL_TREE, expr),
- TYPE_BINFO (type),
- LOOKUP_NORMAL|LOOKUP_NO_CONVERSION
- |LOOKUP_ONLYCONVERTING);
-
- if (init == error_mark_node)
- return error_mark_node;
-
- rval = build_cplus_new (type, init);
- rval = build_up_reference (reftype, rval, flags, 1);
- }
- rval_as_ctor = rval;
- }
-
- if (rval_as_ctor && rval_as_conversion)
- {
- cp_error ("ambiguous conversion from `%T' to `%T'; both user-defined conversion and constructor apply",
- intype, reftype);
- return error_mark_node;
- }
- else if (rval_as_ctor)
- rval = rval_as_ctor;
- else if (rval_as_conversion)
- rval = rval_as_conversion;
- else if (! IS_AGGR_TYPE (type) && ! IS_AGGR_TYPE (intype))
- {
- rval = cp_convert (type, expr);
- if (rval == error_mark_node)
- return error_mark_node;
-
- rval = build_up_reference (reftype, rval, flags, 1);
- }
-
- if (rval && ! TYPE_READONLY (TREE_TYPE (reftype)))
- cp_pedwarn ("initializing non-const `%T' with `%T' will use a temporary",
- reftype, intype);
+ if (rval == NULL_TREE || rval == error_mark_node)
+ return rval;
+ warn_ref_binding (reftype, intype, decl);
+ rval = build_up_reference (reftype, rval, flags, decl);
}
if (rval)
if (TREE_CODE (type) == OFFSET_TYPE)
type = TREE_TYPE (type);
if (TREE_CODE (type) == REFERENCE_TYPE)
- return build_indirect_ref (val, NULL_PTR);
+ return build_indirect_ref (val, NULL);
return val;
}
-\f
-/* See if there is a constructor of type TYPE which will convert
- EXPR. The reference manual seems to suggest (8.5.6) that we need
- not worry about finding constructors for base classes, then converting
- to the derived class.
- MSGP is a pointer to a message that would be an appropriate error
- string. If MSGP is NULL, then we are not interested in reporting
- errors. */
+/* Implicitly convert the lvalue EXPR to another lvalue of type TOTYPE,
+ preserving cv-qualification. */
tree
-convert_to_aggr (type, expr, msgp, protect)
- tree type, expr;
- char **msgp;
- int protect;
+convert_lvalue (totype, expr)
+ tree totype, expr;
{
- tree basetype = type;
- tree name = TYPE_IDENTIFIER (basetype);
- tree function, fndecl, fntype, parmtypes, parmlist, result;
-#if 0
- /* See code below that used this. */
- tree method_name;
-#endif
- tree access;
- int can_be_private, can_be_protected;
-
- if (! TYPE_HAS_CONSTRUCTOR (basetype))
- {
- if (msgp)
- *msgp = "type `%s' does not have a constructor";
- return error_mark_node;
- }
-
- access = access_public_node;
- can_be_private = 0;
- can_be_protected = IDENTIFIER_CLASS_VALUE (name) || name == current_class_name;
-
- parmlist = build_expr_list (NULL_TREE, expr);
- parmtypes = scratch_tree_cons (NULL_TREE, TREE_TYPE (expr), void_list_node);
-
- if (TYPE_USES_VIRTUAL_BASECLASSES (basetype))
- {
- parmtypes = expr_tree_cons (NULL_TREE, integer_type_node, parmtypes);
- parmlist = scratch_tree_cons (NULL_TREE, integer_one_node, parmlist);
- }
-
- /* The type of the first argument will be filled in inside the loop. */
- parmlist = expr_tree_cons (NULL_TREE, integer_zero_node, parmlist);
- parmtypes = scratch_tree_cons (NULL_TREE, build_pointer_type (basetype), parmtypes);
-
- /* No exact conversion was found. See if an approximate
- one will do. */
- fndecl = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (basetype), 0);
-
- {
- int saw_private = 0;
- int saw_protected = 0;
- struct candidate *candidates
- = (struct candidate *) alloca ((decl_list_length (fndecl)+1) * sizeof (struct candidate));
- struct candidate *cp = candidates;
-
- while (fndecl)
- {
- function = fndecl;
- cp->h_len = 2;
- cp->harshness = (struct harshness_code *)
- alloca (3 * sizeof (struct harshness_code));
-
- compute_conversion_costs (fndecl, parmlist, cp, 2);
- if ((cp->h.code & EVIL_CODE) == 0)
- {
- cp->u.field = fndecl;
- if (protect)
- {
- if (TREE_PRIVATE (fndecl))
- access = access_private_node;
- else if (TREE_PROTECTED (fndecl))
- access = access_protected_node;
- else
- access = access_public_node;
- }
- else
- access = access_public_node;
-
- if (access == access_private_node
- ? (basetype == current_class_type
- || is_friend (basetype, cp->function)
- || purpose_member (basetype, DECL_ACCESS (fndecl)))
- : access == access_protected_node
- ? (can_be_protected
- || purpose_member (basetype, DECL_ACCESS (fndecl)))
- : 1)
- {
- if (cp->h.code <= TRIVIAL_CODE)
- goto found_and_ok;
- cp++;
- }
- else
- {
- if (access == access_private_node)
- saw_private = 1;
- else
- saw_protected = 1;
- }
- }
- fndecl = DECL_CHAIN (fndecl);
- }
- if (cp - candidates)
- {
- /* Rank from worst to best. Then cp will point to best one.
- Private fields have their bits flipped. For unsigned
- numbers, this should make them look very large.
- If the best alternate has a (signed) negative value,
- then all we ever saw were private members. */
- if (cp - candidates > 1)
- qsort (candidates, /* char *base */
- cp - candidates, /* int nel */
- sizeof (struct candidate), /* int width */
- (int (*) PROTO((const void *, const void *))) rank_for_overload); /* int (*compar)() */
-
- --cp;
- if (cp->h.code & EVIL_CODE)
- {
- if (msgp)
- *msgp = "ambiguous type conversion possible for `%s'";
- return error_mark_node;
- }
-
- function = cp->function;
- fndecl = cp->u.field;
- goto found_and_ok;
- }
- else if (msgp)
- {
- if (saw_private)
- if (saw_protected)
- *msgp = "only private and protected conversions apply";
- else
- *msgp = "only private conversions apply";
- else if (saw_protected)
- *msgp = "only protected conversions apply";
- else
- *msgp = "no appropriate conversion to type `%s'";
- }
- return error_mark_node;
- }
- /* NOTREACHED */
-
- found:
- if (access == access_private_node)
- if (! can_be_private)
- {
- if (msgp)
- *msgp = TREE_PRIVATE (fndecl)
- ? "conversion to type `%s' is private"
- : "conversion to type `%s' is from private base class";
- return error_mark_node;
- }
- if (access == access_protected_node)
- if (! can_be_protected)
- {
- if (msgp)
- *msgp = TREE_PRIVATE (fndecl)
- ? "conversion to type `%s' is protected"
- : "conversion to type `%s' is from protected base class";
- return error_mark_node;
- }
- function = fndecl;
- found_and_ok:
-
- /* It will convert, but we don't do anything about it yet. */
- if (msgp == 0)
- return NULL_TREE;
-
- fntype = TREE_TYPE (function);
-
- parmlist = convert_arguments (NULL_TREE, TYPE_ARG_TYPES (fntype),
- parmlist, NULL_TREE, LOOKUP_NORMAL);
-
- result = build_call (function, TREE_TYPE (fntype), parmlist);
- return result;
+ totype = cp_build_qualified_type (totype, TYPE_QUALS (TREE_TYPE (expr)));
+ totype = build_reference_type (totype);
+ expr = convert_to_reference (totype, expr, CONV_IMPLICIT, LOOKUP_NORMAL,
+ NULL_TREE);
+ return convert_from_reference (expr);
}
-
+\f
/* Call this when we know (for any reason) that expr is not, in fact,
zero. This routine is like convert_pointer_to, but it pays
attention to which specific instance of what type we want to
tree ptr_type;
tree type, rval;
+ if (intype == error_mark_node)
+ return error_mark_node;
+
if (TREE_CODE (binfo) == TREE_VEC)
type = BINFO_TYPE (binfo);
else if (IS_AGGR_TYPE (binfo))
binfo = NULL_TREE;
}
- ptr_type = cp_build_type_variant (type, TYPE_READONLY (TREE_TYPE (intype)),
- TYPE_VOLATILE (TREE_TYPE (intype)));
+ ptr_type = cp_build_qualified_type (type,
+ CP_TYPE_QUALS (TREE_TYPE (intype)));
ptr_type = build_pointer_type (ptr_type);
- if (ptr_type == TYPE_MAIN_VARIANT (intype))
+ if (same_type_p (ptr_type, TYPE_MAIN_VARIANT (intype)))
return expr;
- if (intype == error_mark_node)
- return error_mark_node;
-
my_friendly_assert (!integer_zerop (expr), 191);
+ intype = TYPE_MAIN_VARIANT (TREE_TYPE (intype));
if (TREE_CODE (type) == RECORD_TYPE
- && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE
- && type != TYPE_MAIN_VARIANT (TREE_TYPE (intype)))
+ && TREE_CODE (intype) == RECORD_TYPE
+ && type != intype)
{
tree path;
int distance
- = get_base_distance (binfo, TYPE_MAIN_VARIANT (TREE_TYPE (intype)),
- 0, &path);
+ = get_base_distance (binfo, intype, 0, &path);
/* This function shouldn't be called with unqualified arguments
but if it is, give them an error message that they can read. */
if (distance < 0)
{
cp_error ("cannot convert a pointer of type `%T' to a pointer of type `%T'",
- TREE_TYPE (intype), type);
+ intype, type);
if (distance == -2)
cp_error ("because `%T' is an ambiguous base class", type);
convert_pointer_to (binfo, expr)
tree binfo, expr;
{
- tree type;
-
- if (TREE_CODE (binfo) == TREE_VEC)
- type = BINFO_TYPE (binfo);
- else if (IS_AGGR_TYPE (binfo))
- type = binfo;
- else
- type = binfo;
- return convert_pointer_to_real (type, expr);
+ return convert_pointer_to_real (binfo, expr);
}
\f
/* C++ conversions, preference to static cast conversions. */
|| TREE_TYPE (e) == error_mark_node)
return error_mark_node;
- if (IS_AGGR_TYPE (type) && (convtype & CONV_FORCE_TEMP))
+ complete_type (type);
+ complete_type (TREE_TYPE (expr));
+
+ e = decl_constant_value (e);
+
+ if (IS_AGGR_TYPE (type) && (convtype & CONV_FORCE_TEMP)
+ /* Some internal structures (vtable_entry_type, sigtbl_ptr_type)
+ don't go through finish_struct, so they don't have the synthesized
+ constructors. So don't force a temporary. */
+ && TYPE_HAS_CONSTRUCTOR (type))
/* We need a new temporary; don't take this shortcut. */;
else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (e)))
- /* Trivial conversion: cv-qualifiers do not matter on rvalues. */
- return fold (build1 (NOP_EXPR, type, e));
-
- if (code == VOID_TYPE && (convtype & CONV_STATIC))
- return build1 (CONVERT_EXPR, type, e);
+ {
+ if (same_type_p (type, TREE_TYPE (e)))
+ /* The call to fold will not always remove the NOP_EXPR as
+ might be expected, since if one of the types is a typedef;
+ the comparsion in fold is just equality of pointers, not a
+ call to comptypes. We don't call fold in this case because
+ that can result in infinite recursion; fold will call
+ convert, which will call ocp_convert, etc. */
+ return e;
+ /* For complex data types, we need to perform componentwise
+ conversion. */
+ else if (TREE_CODE (type) == COMPLEX_TYPE)
+ return fold (convert_to_complex (type, e));
+ else
+ return fold (build1 (NOP_EXPR, type, e));
+ }
-#if 0
- /* This is incorrect. A truncation can't be stripped this way.
- Extensions will be stripped by the use of get_unwidened. */
- if (TREE_CODE (e) == NOP_EXPR)
- return cp_convert (type, TREE_OPERAND (e, 0));
-#endif
+ if (code == VOID_TYPE && (convtype & CONV_STATIC))
+ {
+ e = convert_to_void (e, /*implicit=*/NULL);
+ return e;
+ }
/* Just convert to the type of the member. */
if (code == OFFSET_TYPE)
code = TREE_CODE (type);
}
-#if 0
- if (code == REFERENCE_TYPE)
- return fold (convert_to_reference (type, e, convtype, flags, NULL_TREE));
- else if (TREE_CODE (TREE_TYPE (e)) == REFERENCE_TYPE)
- e = convert_from_reference (e);
-#endif
-
if (TREE_CODE (e) == OFFSET_REF)
e = resolve_offset_ref (e);
- if (TREE_READONLY_DECL_P (e))
- e = decl_constant_value (e);
-
if (INTEGRAL_CODE_P (code))
{
tree intype = TREE_TYPE (e);
/* enum = enum, enum = int, enum = float, (enum)pointer are all
errors. */
- if (flag_int_enum_equivalence == 0
- && TREE_CODE (type) == ENUMERAL_TYPE
+ if (TREE_CODE (type) == ENUMERAL_TYPE
&& ((ARITHMETIC_TYPE_P (intype) && ! (convtype & CONV_STATIC))
|| (TREE_CODE (intype) == POINTER_TYPE)))
{
if (IS_AGGR_TYPE (intype))
{
tree rval;
- rval = build_type_conversion (CONVERT_EXPR, type, e, 1);
+ rval = build_type_conversion (type, e, 1);
if (rval)
return rval;
if (flags & LOOKUP_COMPLAIN)
}
if (code == BOOLEAN_TYPE)
{
+ tree fn = NULL_TREE;
+
/* Common Ada/Pascal programmer's mistake. We always warn
about this since it is so bad. */
if (TREE_CODE (expr) == FUNCTION_DECL)
- cp_warning ("the address of `%D', will always be `true'", expr);
- return truthvalue_conversion (e);
+ fn = expr;
+ else if (TREE_CODE (expr) == ADDR_EXPR
+ && TREE_CODE (TREE_OPERAND (expr, 0)) == FUNCTION_DECL)
+ fn = TREE_OPERAND (expr, 0);
+ if (fn && !DECL_WEAK (fn))
+ cp_warning ("the address of `%D', will always be `true'", fn);
+ return cp_truthvalue_conversion (e);
}
return fold (convert_to_integer (type, e));
}
if (code == POINTER_TYPE || code == REFERENCE_TYPE
|| TYPE_PTRMEMFUNC_P (type))
- return fold (cp_convert_to_pointer (type, e));
+ return fold (cp_convert_to_pointer (type, e, 0));
+ if (code == VECTOR_TYPE)
+ return fold (convert_to_vector (type, e));
if (code == REAL_TYPE || code == COMPLEX_TYPE)
{
if (IS_AGGR_TYPE (TREE_TYPE (e)))
{
tree rval;
- rval = build_type_conversion (CONVERT_EXPR, type, e, 1);
+ rval = build_type_conversion (type, e, 1);
if (rval)
return rval;
else
{
tree dtype = TREE_TYPE (e);
tree ctor = NULL_TREE;
- tree conversion = NULL_TREE;
dtype = TYPE_MAIN_VARIANT (dtype);
- /* Conversion of object pointers or signature pointers/references
- to signature pointers/references. */
-
- if (TYPE_LANG_SPECIFIC (type)
- && (IS_SIGNATURE_POINTER (type) || IS_SIGNATURE_REFERENCE (type)))
- {
- tree constructor = build_signature_pointer_constructor (type, expr);
- tree sig_ty = SIGNATURE_TYPE (type);
- tree sig_ptr;
-
- if (constructor == error_mark_node)
- return error_mark_node;
-
- sig_ptr = get_temp_name (type, 1);
- DECL_INITIAL (sig_ptr) = constructor;
- CLEAR_SIGNATURE (sig_ty);
- cp_finish_decl (sig_ptr, constructor, NULL_TREE, 0, 0);
- SET_SIGNATURE (sig_ty);
- TREE_READONLY (sig_ptr) = 1;
-
- return sig_ptr;
- }
-
/* Conversion between aggregate types. New C++ semantics allow
objects of derived type to be cast to objects of base type.
Old semantics only allowed this between pointers.
There may be some ambiguity between using a constructor
vs. using a type conversion operator when both apply. */
- if (flag_ansi_overloading)
- {
- ctor = e;
-
- if ((flags & LOOKUP_ONLYCONVERTING)
- && ! (IS_AGGR_TYPE (dtype) && DERIVED_FROM_P (type, dtype)))
- {
- ctor = build_user_type_conversion (type, ctor, flags);
- flags |= LOOKUP_NO_CONVERSION;
- }
- if (ctor)
- ctor = build_method_call (NULL_TREE, ctor_identifier,
- build_expr_list (NULL_TREE, ctor),
- TYPE_BINFO (type), flags);
- if (ctor)
- return build_cplus_new (type, ctor);
- }
- else
- {
- if (IS_AGGR_TYPE (dtype) && ! DERIVED_FROM_P (type, dtype)
- && TYPE_HAS_CONVERSION (dtype))
- conversion = build_type_conversion (CONVERT_EXPR, type, e, 1);
+ ctor = e;
- if (conversion == error_mark_node)
- {
- if (flags & LOOKUP_COMPLAIN)
- error ("ambiguous pointer conversion");
- return conversion;
- }
+ if (abstract_virtuals_error (NULL_TREE, type))
+ return error_mark_node;
- if (TYPE_HAS_CONSTRUCTOR (complete_type (type)))
- ctor = build_method_call (NULL_TREE, ctor_identifier,
- build_expr_list (NULL_TREE, e),
- TYPE_BINFO (type),
- (flags & LOOKUP_NORMAL)
- | LOOKUP_SPECULATIVELY
- | (flags & LOOKUP_ONLYCONVERTING)
- | (flags & LOOKUP_NO_CONVERSION)
- | (conversion ? LOOKUP_NO_CONVERSION : 0));
-
- if (ctor == error_mark_node)
- {
- if (flags & LOOKUP_COMPLAIN)
- cp_error ("in conversion to type `%T'", type);
- if (flags & LOOKUP_SPECULATIVELY)
- return NULL_TREE;
- return error_mark_node;
- }
-
- if (conversion && ctor)
- {
- if (flags & LOOKUP_COMPLAIN)
- error ("both constructor and type conversion operator apply");
- if (flags & LOOKUP_SPECULATIVELY)
- return NULL_TREE;
- return error_mark_node;
- }
- else if (conversion)
- return conversion;
- else if (ctor)
- {
- ctor = build_cplus_new (type, ctor);
- return ctor;
- }
- }
+ if ((flags & LOOKUP_ONLYCONVERTING)
+ && ! (IS_AGGR_TYPE (dtype) && DERIVED_FROM_P (type, dtype)))
+ /* For copy-initialization, first we create a temp of the proper type
+ with a user-defined conversion sequence, then we direct-initialize
+ the target with the temp (see [dcl.init]). */
+ ctor = build_user_type_conversion (type, ctor, flags);
+ else
+ ctor = build_method_call (NULL_TREE,
+ complete_ctor_identifier,
+ build_tree_list (NULL_TREE, ctor),
+ TYPE_BINFO (type), flags);
+ if (ctor)
+ return build_cplus_new (type, ctor);
}
/* If TYPE or TREE_TYPE (E) is not on the permanent_obstack,
- then the it won't be hashed and hence compare as not equal,
+ then it won't be hashed and hence compare as not equal,
even when it is. */
if (code == ARRAY_TYPE
&& TREE_TYPE (TREE_TYPE (e)) == TREE_TYPE (type)
return error_mark_node;
}
+/* When an expression is used in a void context, its value is discarded and
+ no lvalue-rvalue and similar conversions happen [expr.static.cast/4,
+ stmt.expr/1, expr.comma/1]. This permits dereferencing an incomplete type
+ in a void context. The C++ standard does not define what an `access' to an
+ object is, but there is reason to beleive that it is the lvalue to rvalue
+ conversion -- if it were not, `*&*p = 1' would violate [expr]/4 in that it
+ accesses `*p' not to calculate the value to be stored. But, dcl.type.cv/8
+ indicates that volatile semantics should be the same between C and C++
+ where ever possible. C leaves it implementation defined as to what
+ constitutes an access to a volatile. So, we interpret `*vp' as a read of
+ the volatile object `vp' points to, unless that is an incomplete type. For
+ volatile references we do not do this interpretation, because that would
+ make it impossible to ignore the reference return value from functions. We
+ issue warnings in the confusing cases.
+
+ IMPLICIT is tells us the context of an implicit void conversion. */
+
+tree
+convert_to_void (expr, implicit)
+ tree expr;
+ const char *implicit;
+{
+ if (expr == error_mark_node
+ || TREE_TYPE (expr) == error_mark_node)
+ return error_mark_node;
+ if (!TREE_TYPE (expr))
+ return expr;
+ if (VOID_TYPE_P (TREE_TYPE (expr)))
+ return expr;
+ switch (TREE_CODE (expr))
+ {
+ case COND_EXPR:
+ {
+ /* The two parts of a cond expr might be separate lvalues. */
+ tree op1 = TREE_OPERAND (expr,1);
+ tree op2 = TREE_OPERAND (expr,2);
+ tree new_op1 = convert_to_void (op1, implicit);
+ tree new_op2 = convert_to_void (op2, implicit);
+
+ if (new_op1 != op1 || new_op2 != op2)
+ expr = build (COND_EXPR,
+ implicit ? TREE_TYPE (expr) : void_type_node,
+ TREE_OPERAND (expr, 0), new_op1, new_op2);
+ break;
+ }
+
+ case COMPOUND_EXPR:
+ {
+ /* The second part of a compound expr contains the value. */
+ tree op1 = TREE_OPERAND (expr,1);
+ tree new_op1 = convert_to_void (op1, implicit);
+
+ if (new_op1 != op1)
+ {
+ tree t = build (COMPOUND_EXPR, TREE_TYPE (new_op1),
+ TREE_OPERAND (expr, 0), new_op1);
+ TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
+ expr = t;
+ }
+
+ break;
+ }
+
+ case NON_LVALUE_EXPR:
+ case NOP_EXPR:
+ /* These have already decayed to rvalue. */
+ break;
+
+ case CALL_EXPR: /* we have a special meaning for volatile void fn() */
+ break;
+
+ case INDIRECT_REF:
+ {
+ tree type = TREE_TYPE (expr);
+ int is_reference = TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0)))
+ == REFERENCE_TYPE;
+ int is_volatile = TYPE_VOLATILE (type);
+ int is_complete = COMPLETE_TYPE_P (complete_type (type));
+
+ if (is_volatile && !is_complete)
+ cp_warning ("object of incomplete type `%T' will not be accessed in %s",
+ type, implicit ? implicit : "void context");
+ else if (is_reference && is_volatile)
+ cp_warning ("object of type `%T' will not be accessed in %s",
+ TREE_TYPE (TREE_OPERAND (expr, 0)),
+ implicit ? implicit : "void context");
+ if (is_reference || !is_volatile || !is_complete)
+ expr = TREE_OPERAND (expr, 0);
+
+ break;
+ }
+
+ case VAR_DECL:
+ {
+ /* External variables might be incomplete. */
+ tree type = TREE_TYPE (expr);
+ int is_complete = COMPLETE_TYPE_P (complete_type (type));
+
+ if (TYPE_VOLATILE (type) && !is_complete)
+ cp_warning ("object `%E' of incomplete type `%T' will not be accessed in %s",
+ expr, type, implicit ? implicit : "void context");
+ break;
+ }
+
+ case OFFSET_REF:
+ expr = resolve_offset_ref (expr);
+ break;
+
+ default:;
+ }
+ {
+ tree probe = expr;
+
+ if (TREE_CODE (probe) == ADDR_EXPR)
+ probe = TREE_OPERAND (expr, 0);
+ if (type_unknown_p (probe))
+ {
+ /* [over.over] enumerates the places where we can take the address
+ of an overloaded function, and this is not one of them. */
+ cp_pedwarn ("%s cannot resolve address of overloaded function",
+ implicit ? implicit : "void cast");
+ }
+ else if (implicit && probe == expr && is_overloaded_fn (probe))
+ /* Only warn when there is no &. */
+ cp_warning ("%s is a reference, not call, to function `%E'",
+ implicit, expr);
+ }
+
+ if (expr != error_mark_node && !VOID_TYPE_P (TREE_TYPE (expr)))
+ {
+ /* FIXME: This is where we should check for expressions with no
+ effects. At the moment we do that in both build_x_component_expr
+ and expand_expr_stmt -- inconsistently too. For the moment
+ leave implicit void conversions unadorned so that expand_expr_stmt
+ has a chance of detecting some of the cases. */
+ if (!implicit)
+ expr = build1 (CONVERT_EXPR, void_type_node, expr);
+ }
+ return expr;
+}
+
/* Create an expression whose value is that of EXPR,
converted to type TYPE. The TREE_TYPE of the value
is always TYPE. This function implements all reasonable
conversions to/from basetypes may involve memory references
(vbases) and adding or subtracting small values (multiple
inheritance), but it calls convert from the constant folding code
- on subtrees of already build trees after it has ripped them apart.
+ on subtrees of already built trees after it has ripped them apart.
Also, if we ever support range variables, we'll probably also have to
do a little bit more work. */
if (POINTER_TYPE_P (type) && POINTER_TYPE_P (intype))
{
- if (TREE_READONLY_DECL_P (expr))
- expr = decl_constant_value (expr);
+ expr = decl_constant_value (expr);
return fold (build1 (NOP_EXPR, type, expr));
}
return ocp_convert (type, e, CONV_C_CAST|convtype, LOOKUP_NORMAL);
}
-/* Subroutine of build_type_conversion. */
-
-static tree
-build_type_conversion_1 (xtype, basetype, expr, typename, for_sure)
- tree xtype, basetype;
- tree expr;
- tree typename;
- int for_sure;
-{
- tree rval;
- int flags;
-
- if (for_sure == 0)
- flags = LOOKUP_PROTECT|LOOKUP_ONLYCONVERTING;
- else
- flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING;
-
- rval = build_method_call (expr, typename, NULL_TREE, NULL_TREE, flags);
- if (rval == error_mark_node)
- {
- if (for_sure == 0)
- return NULL_TREE;
- return error_mark_node;
- }
-
- if (IS_AGGR_TYPE (TREE_TYPE (rval)))
- return rval;
-
- if (warn_cast_qual
- && TREE_TYPE (xtype)
- && (TREE_READONLY (TREE_TYPE (TREE_TYPE (rval)))
- > TREE_READONLY (TREE_TYPE (xtype))))
- warning ("user-defined conversion casting away `const'");
- return cp_convert (xtype, rval);
-}
-
/* Convert an aggregate EXPR to type XTYPE. If a conversion
exists, return the attempted conversion. This may
return ERROR_MARK_NODE if the conversion is not
(jason 8/9/95) */
tree
-build_type_conversion (code, xtype, expr, for_sure)
- enum tree_code code;
+build_type_conversion (xtype, expr, for_sure)
tree xtype, expr;
int for_sure;
{
/* C++: check to see if we can convert this aggregate type
into the required type. */
- tree basetype;
- tree conv;
- tree winner = NULL_TREE;
-
- if (flag_ansi_overloading)
- return build_user_type_conversion
- (xtype, expr, for_sure ? LOOKUP_NORMAL : 0);
-
- if (expr == error_mark_node)
- return error_mark_node;
-
- basetype = TREE_TYPE (expr);
- if (TREE_CODE (basetype) == REFERENCE_TYPE)
- basetype = TREE_TYPE (basetype);
-
- basetype = TYPE_MAIN_VARIANT (basetype);
- if (! TYPE_LANG_SPECIFIC (basetype) || ! TYPE_HAS_CONVERSION (basetype))
- return NULL_TREE;
-
- /* Do we have an exact match? */
- {
- tree typename = build_typename_overload (xtype);
- if (lookup_fnfields (TYPE_BINFO (basetype), typename, 0))
- return build_type_conversion_1 (xtype, basetype, expr, typename,
- for_sure);
- }
-
- /* Nope; try looking for others. */
- for (conv = lookup_conversions (basetype); conv; conv = TREE_CHAIN (conv))
- {
- tree cand = TREE_VALUE (conv);
-
- if (winner && winner == cand)
- continue;
-
- if (can_convert (xtype, TREE_TYPE (TREE_TYPE (cand))))
- {
- if (winner)
- {
- if (for_sure)
- {
- cp_error ("ambiguous conversion from `%T' to `%T'", basetype,
- xtype);
- cp_error (" candidate conversions include `%D' and `%D'",
- winner, cand);
- }
- return NULL_TREE;
- }
- else
- winner = cand;
- }
- }
-
- if (winner)
- return build_type_conversion_1 (xtype, basetype, expr,
- DECL_NAME (winner), for_sure);
-
- return NULL_TREE;
+ return build_user_type_conversion
+ (xtype, expr, for_sure ? LOOKUP_NORMAL : 0);
}
/* Convert the given EXPR to one of a group of types suitable for use in an
int complain;
{
tree basetype = TREE_TYPE (expr);
- tree conv;
+ tree conv = NULL_TREE;
tree winner = NULL_TREE;
- if (TREE_CODE (basetype) == OFFSET_TYPE)
+ if (expr == null_node
+ && (desires & WANT_INT)
+ && !(desires & WANT_NULL))
+ cp_warning ("converting NULL to non-pointer type");
+
+ if (TREE_CODE (expr) == OFFSET_REF)
expr = resolve_offset_ref (expr);
expr = convert_from_reference (expr);
basetype = TREE_TYPE (expr);
+ if (basetype == error_mark_node)
+ return error_mark_node;
+
if (! IS_AGGR_TYPE (basetype))
switch (TREE_CODE (basetype))
{
case INTEGER_TYPE:
- if ((desires & WANT_NULL) && TREE_CODE (expr) == INTEGER_CST
- && integer_zerop (expr))
+ if ((desires & WANT_NULL) && null_ptr_cst_p (expr))
return expr;
/* else fall through... */
return NULL_TREE;
}
+ /* The code for conversions from class type is currently only used for
+ delete expressions. Other expressions are handled by build_new_op. */
+
if (! TYPE_HAS_CONVERSION (basetype))
return NULL_TREE;
tree type = TREE_TYPE (TREE_TYPE (winner));
if (TREE_CODE (type) == REFERENCE_TYPE)
type = TREE_TYPE (type);
- return build_type_conversion_1 (type, basetype, expr,
- DECL_NAME (winner), 1);
+ return build_user_type_conversion (type, expr, LOOKUP_NORMAL);
}
return NULL_TREE;
}
-/* Must convert two aggregate types to non-aggregate type.
- Attempts to find a non-ambiguous, "best" type conversion.
-
- Return 1 on success, 0 on failure.
-
- @@ What are the real semantics of this supposed to be??? */
-
-int
-build_default_binary_type_conversion (code, arg1, arg2)
- enum tree_code code;
- tree *arg1, *arg2;
-{
- switch (code)
- {
- case MULT_EXPR:
- case TRUNC_DIV_EXPR:
- case CEIL_DIV_EXPR:
- case FLOOR_DIV_EXPR:
- case ROUND_DIV_EXPR:
- case EXACT_DIV_EXPR:
- *arg1 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg1, 0);
- *arg2 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg2, 0);
- break;
-
- case TRUNC_MOD_EXPR:
- case FLOOR_MOD_EXPR:
- case LSHIFT_EXPR:
- case RSHIFT_EXPR:
- case BIT_AND_EXPR:
- case BIT_XOR_EXPR:
- case BIT_IOR_EXPR:
- *arg1 = build_expr_type_conversion (WANT_INT | WANT_ENUM, *arg1, 0);
- *arg2 = build_expr_type_conversion (WANT_INT | WANT_ENUM, *arg2, 0);
- break;
-
- case PLUS_EXPR:
- {
- tree a1, a2, p1, p2;
- int wins;
-
- a1 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg1, 0);
- a2 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg2, 0);
- p1 = build_expr_type_conversion (WANT_POINTER, *arg1, 0);
- p2 = build_expr_type_conversion (WANT_POINTER, *arg2, 0);
-
- wins = (a1 && a2) + (a1 && p2) + (p1 && a2);
-
- if (wins > 1)
- error ("ambiguous default type conversion for `operator +'");
-
- if (a1 && a2)
- *arg1 = a1, *arg2 = a2;
- else if (a1 && p2)
- *arg1 = a1, *arg2 = p2;
- else
- *arg1 = p1, *arg2 = a2;
- break;
- }
-
- case MINUS_EXPR:
- {
- tree a1, a2, p1, p2;
- int wins;
-
- a1 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg1, 0);
- a2 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg2, 0);
- p1 = build_expr_type_conversion (WANT_POINTER, *arg1, 0);
- p2 = build_expr_type_conversion (WANT_POINTER, *arg2, 0);
-
- wins = (a1 && a2) + (p1 && p2) + (p1 && a2);
-
- if (wins > 1)
- error ("ambiguous default type conversion for `operator -'");
-
- if (a1 && a2)
- *arg1 = a1, *arg2 = a2;
- else if (p1 && p2)
- *arg1 = p1, *arg2 = p2;
- else
- *arg1 = p1, *arg2 = a2;
- break;
- }
-
- case GT_EXPR:
- case LT_EXPR:
- case GE_EXPR:
- case LE_EXPR:
- case EQ_EXPR:
- case NE_EXPR:
- {
- tree a1, a2, p1, p2;
- int wins;
-
- a1 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg1, 0);
- a2 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg2, 0);
- p1 = build_expr_type_conversion (WANT_POINTER | WANT_NULL, *arg1, 0);
- p2 = build_expr_type_conversion (WANT_POINTER | WANT_NULL, *arg2, 0);
-
- wins = (a1 && a2) + (p1 && p2);
-
- if (wins > 1)
- cp_error ("ambiguous default type conversion for `%O'", code);
-
- if (a1 && a2)
- *arg1 = a1, *arg2 = a2;
- else
- *arg1 = p1, *arg2 = p2;
- break;
- }
-
- case TRUTH_ANDIF_EXPR:
- case TRUTH_ORIF_EXPR:
- *arg1 = cp_convert (boolean_type_node, *arg1);
- *arg2 = cp_convert (boolean_type_node, *arg2);
- break;
-
- default:
- *arg1 = NULL_TREE;
- *arg2 = NULL_TREE;
- }
-
- if (*arg1 == error_mark_node || *arg2 == error_mark_node)
- cp_error ("ambiguous default type conversion for `%O'", code);
-
- if (*arg1 && *arg2)
- return 1;
-
- return 0;
-}
-
/* Implements integral promotion (4.1) and float->double promotion. */
tree
type_promotes_to (type)
tree type;
{
- int constp, volatilep;
+ int type_quals;
if (type == error_mark_node)
return error_mark_node;
- constp = TYPE_READONLY (type);
- volatilep = TYPE_VOLATILE (type);
+ type_quals = CP_TYPE_QUALS (type);
type = TYPE_MAIN_VARIANT (type);
/* bool always promotes to int (not unsigned), even if it's the same
else
type = totype;
}
- else if (C_PROMOTING_INTEGER_TYPE_P (type))
+ else if (c_promoting_integer_type_p (type))
{
/* Retain unsignedness if really not getting bigger. */
if (TREE_UNSIGNED (type)
else if (type == float_type_node)
type = double_type_node;
- return cp_build_type_variant (type, constp, volatilep);
+ return cp_build_qualified_type (type, type_quals);
+}
+
+/* The routines below this point are carefully written to conform to
+ the standard. They use the same terminology, and follow the rules
+ closely. Although they are used only in pt.c at the moment, they
+ should presumably be used everywhere in the future. */
+
+/* Attempt to perform qualification conversions on EXPR to convert it
+ to TYPE. Return the resulting expression, or error_mark_node if
+ the conversion was impossible. */
+
+tree
+perform_qualification_conversions (type, expr)
+ tree type;
+ tree expr;
+{
+ if (TREE_CODE (type) == POINTER_TYPE
+ && TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE
+ && comp_ptr_ttypes (TREE_TYPE (type), TREE_TYPE (TREE_TYPE (expr))))
+ return build1 (NOP_EXPR, type, expr);
+ else
+ return error_mark_node;
}
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