* langhooks-def.h (LANG_HOOKS_EXPR_SIZE): New macro.
* langhooks.c (lhd_expr_size): Define default.
* langhooks.h (struct lang_hooks): Add expr_size.
* explow.c (expr_size): Call it.
* expr.c (store_expr): Don't copy an expression of size zero.
(expand_expr) [CONSTRUCTOR]: Use expr_size to calculate how much
to store.
* Makefile.in (builtins.o): Depend on langhooks.h.
* cp-lang.c (LANG_HOOKS_EXPR_SIZE): Define.
(cp_expr_size): New fn.
* call.c (build_over_call): Lose empty class hackery.
(convert_arg_to_ellipsis): Promote non-POD warning to error.
* typeck.c (build_modify_expr): Don't use save_expr on an lvalue.
From-SVN: r55983
+2002-08-02 Jason Merrill <jason@redhat.com>
+
+ * langhooks-def.h (LANG_HOOKS_EXPR_SIZE): New macro.
+ * langhooks.c (lhd_expr_size): Define default.
+ * langhooks.h (struct lang_hooks): Add expr_size.
+ * explow.c (expr_size): Call it.
+ * expr.c (store_expr): Don't copy an expression of size zero.
+ (expand_expr) [CONSTRUCTOR]: Use expr_size to calculate how much
+ to store.
+ * Makefile.in (builtins.o): Depend on langhooks.h.
+
2002-08-02 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
* Makefile.in (ra-debug.o): Depend on $(TM_P_H).
builtins.o : builtins.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) $(TREE_H) flags.h \
$(TARGET_H) function.h $(REGS_H) $(EXPR_H) $(OPTABS_H) insn-config.h \
$(RECOG_H) output.h typeclass.h hard-reg-set.h toplev.h hard-reg-set.h \
- except.h $(TM_P_H) $(PREDICT_H) libfuncs.h real.h
+ except.h $(TM_P_H) $(PREDICT_H) libfuncs.h real.h langhooks.h
calls.o : calls.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) $(TREE_H) flags.h \
$(EXPR_H) langhooks.h \
libfuncs.h $(REGS_H) toplev.h output.h function.h $(TIMEVAR_H) $(TM_P_H)
2002-08-02 Jason Merrill <jason@redhat.com>
+ * cp-lang.c (LANG_HOOKS_EXPR_SIZE): Define.
+ (cp_expr_size): New fn.
+ * call.c (build_over_call): Lose empty class hackery.
+ (convert_arg_to_ellipsis): Promote non-POD warning to error.
+ * typeck.c (build_modify_expr): Don't use save_expr on an lvalue.
+
* semantics.c (expand_body): Do tree optimization in the function
context, too.
if (arg != error_mark_node && ! pod_type_p (TREE_TYPE (arg)))
{
- /* Undefined behaviour [expr.call] 5.2.2/7. */
- warning ("cannot pass objects of non-POD type `%#T' through `...'",
- TREE_TYPE (arg));
+ /* Undefined behaviour [expr.call] 5.2.2/7. We used to just warn
+ here and do a bitwise copy, but now cp_expr_size will abort if we
+ try to do that. */
+ error ("cannot pass objects of non-POD type `%#T' through `...'",
+ TREE_TYPE (arg));
+ arg = error_mark_node;
}
return arg;
else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
return build_target_expr_with_type (arg, DECL_CONTEXT (fn));
}
- else if ((!real_lvalue_p (arg)
- || TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
- /* Empty classes have padding which can be hidden
- inside an (empty) base of the class. This must not
- be touched as it might overlay things. When the
- gcc core learns about empty classes, we can treat it
- like other classes. */
- && !(is_empty_class (DECL_CONTEXT (fn))
- && TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn))))
+ else if (!real_lvalue_p (arg)
+ || TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
{
tree address;
tree to = stabilize_reference
(build_indirect_ref (TREE_VALUE (converted_args), 0));
arg = build_indirect_ref (TREE_VALUE (TREE_CHAIN (converted_args)), 0);
- if (is_empty_class (TREE_TYPE (to)))
- {
- TREE_USED (arg) = 1;
-
- val = build (COMPOUND_EXPR, DECL_CONTEXT (fn), arg, to);
- /* Even though the assignment may not actually result in any
- code being generated, we do not want to warn about the
- assignment having no effect. That would be confusing to
- users who may be performing the assignment as part of a
- generic algorithm, for example.
-
- Ideally, the notions of having side-effects and of being
- useless would be orthogonal. */
- TREE_SIDE_EFFECTS (val) = 1;
- TREE_NO_UNUSED_WARNING (val) = 1;
- }
- else
- val = build (MODIFY_EXPR, TREE_TYPE (to), to, arg);
+ val = build (MODIFY_EXPR, TREE_TYPE (to), to, arg);
return val;
}
static HOST_WIDE_INT cxx_get_alias_set PARAMS ((tree));
static bool ok_to_generate_alias_set_for_type PARAMS ((tree));
static bool cxx_warn_unused_global_decl PARAMS ((tree));
+static tree cp_expr_size PARAMS ((tree));
#undef LANG_HOOKS_NAME
#define LANG_HOOKS_NAME "GNU C++"
#define LANG_HOOKS_TREE_DUMP_DUMP_TREE_FN cp_dump_tree
#undef LANG_HOOKS_TREE_DUMP_TYPE_QUALS_FN
#define LANG_HOOKS_TREE_DUMP_TYPE_QUALS_FN cp_type_quals
+#undef LANG_HOOKS_EXPR_SIZE
+#define LANG_HOOKS_EXPR_SIZE cp_expr_size
#undef LANG_HOOKS_MAKE_TYPE
#define LANG_HOOKS_MAKE_TYPE cxx_make_type
return true;
}
+
+/* Langhook for expr_size: Tell the backend that the value of an expression
+ of non-POD class type does not include any tail padding; a derived class
+ might have allocated something there. */
+
+static tree
+cp_expr_size (exp)
+ tree exp;
+{
+ if (CLASS_TYPE_P (TREE_TYPE (exp)))
+ {
+ /* The backend should not be interested in the size of an expression
+ of a type with both of these set; all copies of such types must go
+ through a constructor or assignment op. */
+ if (TYPE_HAS_COMPLEX_INIT_REF (TREE_TYPE (exp))
+ && TYPE_HAS_COMPLEX_ASSIGN_REF (TREE_TYPE (exp)))
+ abort ();
+ /* This would be wrong for a type with virtual bases, but they are
+ caught by the abort above. */
+ return CLASSTYPE_SIZE_UNIT (TREE_TYPE (exp));
+ }
+ else
+ /* Use the default code. */
+ return lhd_expr_size (exp);
+}
except that the RHS goes through a save-expr
so the code to compute it is only emitted once. */
tree cond;
+ tree preeval = NULL_TREE;
- rhs = save_expr (rhs);
+ rhs = stabilize_expr (rhs, &preeval);
/* Check this here to avoid odd errors when trying to convert
a throw to the type of the COND_EXPR. */
return cond;
/* Make sure the code to compute the rhs comes out
before the split. */
- return build (COMPOUND_EXPR, TREE_TYPE (lhs),
- /* Cast to void to suppress warning
- from warn_if_unused_value. */
- cp_convert (void_type_node, rhs), cond);
+ return build (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
}
case OFFSET_REF:
#include "insn-config.h"
#include "ggc.h"
#include "recog.h"
+#include "langhooks.h"
static rtx break_out_memory_refs PARAMS ((rtx));
static void emit_stack_probe PARAMS ((rtx));
expr_size (exp)
tree exp;
{
- tree size;
-
- if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
- && DECL_SIZE_UNIT (exp) != 0)
- size = DECL_SIZE_UNIT (exp);
- else
- size = size_in_bytes (TREE_TYPE (exp));
+ tree size = (*lang_hooks.expr_size) (exp);
if (TREE_CODE (size) != INTEGER_CST
&& contains_placeholder_p (size))
size = build (WITH_RECORD_EXPR, sizetype, size, exp);
return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), 0);
-
}
\f
/* Return a copy of X in which all memory references
|| (temp != target && (side_effects_p (temp)
|| side_effects_p (target))))
&& TREE_CODE (exp) != ERROR_MARK
+ /* If there's nothing to copy, don't bother. */
+ && expr_size (exp) != const0_rtx
&& ! dont_store_target
/* If store_expr stores a DECL whose DECL_RTL(exp) == TARGET,
but TARGET is not valid memory reference, TEMP will differ
* TYPE_QUAL_CONST))),
0, TREE_ADDRESSABLE (exp), 1);
- store_constructor (exp, target, 0,
- int_size_in_bytes (TREE_TYPE (exp)));
+ store_constructor (exp, target, 0, INTVAL (expr_size (exp)));
return target;
}
extern bool lhd_warn_unused_global_decl PARAMS ((tree));
extern void lhd_incomplete_type_error PARAMS ((tree, tree));
extern tree lhd_type_promotes_to PARAMS ((tree));
+extern tree lhd_expr_size PARAMS ((tree));
/* Declarations of default tree inlining hooks. */
tree lhd_tree_inlining_walk_subtrees PARAMS ((tree *, int *,
#define LANG_HOOKS_PRINT_IDENTIFIER lhd_print_tree_nothing
#define LANG_HOOKS_PRINT_ERROR_FUNCTION lhd_print_error_function
#define LANG_HOOKS_DECL_PRINTABLE_NAME lhd_decl_printable_name
+#define LANG_HOOKS_EXPR_SIZE lhd_expr_size
#define LANG_HOOKS_FUNCTION_INIT lhd_do_nothing_f
#define LANG_HOOKS_FUNCTION_FINAL lhd_do_nothing_f
LANG_HOOKS_PRINT_IDENTIFIER, \
LANG_HOOKS_DECL_PRINTABLE_NAME, \
LANG_HOOKS_PRINT_ERROR_FUNCTION, \
+ LANG_HOOKS_EXPR_SIZE, \
LANG_HOOKS_ATTRIBUTE_TABLE, \
LANG_HOOKS_COMMON_ATTRIBUTE_TABLE, \
LANG_HOOKS_FORMAT_ATTRIBUTE_TABLE, \
{
return TYPE_QUALS (t);
}
+
+/* lang_hooks.expr_size: Determine the size of the value of an expression T
+ in a language-specific way. Returns a tree for the size in bytes. */
+
+tree
+lhd_expr_size (exp)
+ tree exp;
+{
+ if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
+ && DECL_SIZE_UNIT (exp) != 0)
+ return DECL_SIZE_UNIT (exp);
+ else
+ return size_in_bytes (TREE_TYPE (exp));
+}
void (*print_error_function) PARAMS ((struct diagnostic_context *,
const char *));
+ /* Called from expr_size to calculate the size of the value of an
+ expression in a language-dependent way. Returns a tree for the size
+ in bytes. A frontend can call lhd_expr_size to get the default
+ semantics in cases that it doesn't want to handle specially. */
+ tree (*expr_size) PARAMS ((tree));
+
/* Pointers to machine-independent attribute tables, for front ends
using attribs.c. If one is NULL, it is ignored. Respectively, a
table of attributes specific to the language, a table of
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