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re PR c++/160 (Reference variables not initialized correctly in constructor initializer list using , operator)

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cp:
	PR c++/160
	* typeck.c (build_modify_expr): Remove old unreachable code & tidy
	up. Don't stabilize_references when initializing a reference.
testsuite:
	* g++.dg/other/init2.C: New test.

From-SVN: r48307
This commit is contained in:
Nathan Sidwell 2001-12-24 20:52:36 +00:00 committed by Nathan Sidwell
parent fdfc290b94
commit a56ca89955
4 changed files with 138 additions and 125 deletions
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6
gcc/cp/ChangeLog
View File

@ -1,3 +1,9 @@
2001-12-24 Nathan Sidwell <nathan@codesourcery.com>
PR c++/160
* typeck.c (build_modify_expr): Remove old unreachable code & tidy
up. Don't stabilize_references when initializing a reference.
2001-12-23 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
* decl2.c (lang_f_options): Const-ify.

148
gcc/cp/typeck.c
View File

@ -5494,13 +5494,7 @@ build_modify_expr (lhs, modifycode, rhs)
if (lhs == error_mark_node || rhs == error_mark_node)
return error_mark_node;
/* Types that aren't fully specified cannot be used in assignments. */
lhs = require_complete_type (lhs);
newrhs = rhs;
/* Handle control structure constructs used as "lvalues". */
switch (TREE_CODE (lhs))
{
/* Handle --foo = 5; as these are valid constructs in C++ */
@ -5532,13 +5526,14 @@ build_modify_expr (lhs, modifycode, rhs)
/* Handle (a ? b : c) used as an "lvalue". */
case COND_EXPR:
rhs = save_expr (rhs);
{
/* Produce (a ? (b = rhs) : (c = rhs))
except that the RHS goes through a save-expr
so the code to compute it is only emitted once. */
tree cond;
rhs = save_expr (rhs);
/* Check this here to avoid odd errors when trying to convert
a throw to the type of the COND_EXPR. */
if (!lvalue_or_else (lhs, "assignment"))
@ -5558,54 +5553,27 @@ build_modify_expr (lhs, modifycode, rhs)
/* Make sure the code to compute the rhs comes out
before the split. */
return build (COMPOUND_EXPR, TREE_TYPE (lhs),
/* Case to void to suppress warning
/* Cast to void to suppress warning
from warn_if_unused_value. */
cp_convert (void_type_node, rhs), cond);
}
case OFFSET_REF:
lhs = resolve_offset_ref (lhs);
if (lhs == error_mark_node)
return error_mark_node;
olhstype = lhstype = TREE_TYPE (lhs);
default:
break;
}
if (TREE_CODE (lhs) == OFFSET_REF)
{
if (TREE_OPERAND (lhs, 0) == NULL_TREE)
{
/* Static class member? */
tree member = TREE_OPERAND (lhs, 1);
if (TREE_CODE (member) == VAR_DECL)
lhs = member;
else
{
compiler_error ("invalid static class member");
return error_mark_node;
}
}
else
lhs = resolve_offset_ref (lhs);
olhstype = lhstype = TREE_TYPE (lhs);
}
if (lhs == error_mark_node)
return lhs;
if (TREE_CODE (lhstype) == REFERENCE_TYPE
&& modifycode != INIT_EXPR)
{
lhs = convert_from_reference (lhs);
olhstype = lhstype = TREE_TYPE (lhs);
}
/* If a binary op has been requested, combine the old LHS value with the RHS
producing the value we should actually store into the LHS. */
if (modifycode == INIT_EXPR)
{
if (TREE_CODE (rhs) == CONSTRUCTOR)
{
if (! same_type_p (TREE_TYPE (rhs), lhstype))
abort ();
my_friendly_assert (same_type_p (TREE_TYPE (rhs), lhstype),
20011220);
result = build (INIT_EXPR, lhstype, lhs, rhs);
TREE_SIDE_EFFECTS (result) = 1;
return result;
@ -5622,7 +5590,18 @@ build_modify_expr (lhs, modifycode, rhs)
return result;
}
}
else if (modifycode == NOP_EXPR)
else
{
if (TREE_CODE (lhstype) == REFERENCE_TYPE)
{
lhs = convert_from_reference (lhs);
olhstype = lhstype = TREE_TYPE (lhs);
}
lhs = require_complete_type (lhs);
if (lhs == error_mark_node)
return error_mark_node;
if (modifycode == NOP_EXPR)
{
/* `operator=' is not an inheritable operator. */
if (! IS_AGGR_TYPE (lhstype))
@ -5637,12 +5616,14 @@ build_modify_expr (lhs, modifycode, rhs)
}
lhstype = olhstype;
}
else if (PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE))
{
my_friendly_abort (978652);
}
else
{
/* A binary op has been requested. Combine the old LHS
value with the RHS producing the value we should actually
store into the LHS. */
my_friendly_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE),
978652);
lhs = stabilize_reference (lhs);
newrhs = cp_build_binary_op (modifycode, lhs, rhs);
if (newrhs == error_mark_node)
@ -5651,6 +5632,13 @@ build_modify_expr (lhs, modifycode, rhs)
TREE_TYPE (lhs), TREE_TYPE (rhs));
return error_mark_node;
}
/* Now it looks like a plain assignment. */
modifycode = NOP_EXPR;
}
my_friendly_assert (TREE_CODE (lhstype) != REFERENCE_TYPE, 20011220);
my_friendly_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE,
20011220);
}
/* Handle a cast used as an "lvalue".
@ -5669,14 +5657,15 @@ build_modify_expr (lhs, modifycode, rhs)
case FIX_FLOOR_EXPR:
case FIX_ROUND_EXPR:
case FIX_CEIL_EXPR:
{
tree inner_lhs = TREE_OPERAND (lhs, 0);
tree result;
if (TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
|| TREE_CODE (TREE_TYPE (newrhs)) == FUNCTION_TYPE
|| TREE_CODE (TREE_TYPE (newrhs)) == METHOD_TYPE
|| TREE_CODE (TREE_TYPE (newrhs)) == OFFSET_TYPE)
newrhs = default_conversion (newrhs);
{
tree inner_lhs = TREE_OPERAND (lhs, 0);
tree result;
/* ISO C++ 5.4/1: The result is an lvalue if T is a reference
type, otherwise the result is an rvalue. */
@ -5703,23 +5692,23 @@ build_modify_expr (lhs, modifycode, rhs)
GNU_xref_assign (lhs);
/* Warn about storing in something that is `const'. */
/* For C++, don't warn if this is initialization. */
/* Warn about modifying something that is `const'. Don't warn if
this is initialization. */
if (modifycode != INIT_EXPR
&& (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
/* Functions are not modifiable, even though they are
lvalues. */
|| TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
|| TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
/* If it's an aggregate and any field is const, then it is
effectively const. */
|| (IS_AGGR_TYPE_CODE (TREE_CODE (lhstype))
&& C_TYPE_FIELDS_READONLY (lhstype))
|| (TREE_CODE (lhstype) == REFERENCE_TYPE
&& CP_TYPE_CONST_P (TREE_TYPE (lhstype)))))
&& C_TYPE_FIELDS_READONLY (lhstype))))
readonly_error (lhs, "assignment", 0);
/* If storing into a structure or union member,
it has probably been given type `int'.
Compute the type that would go with
the actual amount of storage the member occupies. */
/* If storing into a structure or union member, it has probably been
given type `int'. Compute the type that would go with the actual
amount of storage the member occupies. */
if (TREE_CODE (lhs) == COMPONENT_REF
&& (TREE_CODE (lhstype) == INTEGER_TYPE
@ -5738,39 +5727,13 @@ build_modify_expr (lhs, modifycode, rhs)
}
}
if (modifycode != INIT_EXPR)
if (TREE_CODE (lhstype) != REFERENCE_TYPE)
{
/* Make modifycode now either a NOP_EXPR or an INIT_EXPR. */
modifycode = NOP_EXPR;
/* Reference-bashing */
if (TREE_CODE (lhstype) == REFERENCE_TYPE)
{
tree tmp = convert_from_reference (lhs);
lhstype = TREE_TYPE (tmp);
if (!COMPLETE_TYPE_P (lhstype))
{
incomplete_type_error (lhs, lhstype);
return error_mark_node;
}
lhs = tmp;
olhstype = lhstype;
}
if (TREE_CODE (TREE_TYPE (newrhs)) == REFERENCE_TYPE)
{
tree tmp = convert_from_reference (newrhs);
if (!COMPLETE_TYPE_P (TREE_TYPE (tmp)))
{
incomplete_type_error (newrhs, TREE_TYPE (tmp));
return error_mark_node;
}
newrhs = tmp;
}
}
if (TREE_SIDE_EFFECTS (lhs))
lhs = stabilize_reference (lhs);
if (TREE_SIDE_EFFECTS (newrhs))
newrhs = stabilize_reference (newrhs);
}
/* Convert new value to destination type. */
@ -5795,17 +5758,8 @@ build_modify_expr (lhs, modifycode, rhs)
}
if (modifycode == INIT_EXPR)
{
newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
"initialization", NULL_TREE, 0);
if (current_function_decl &&
lhs == DECL_RESULT (current_function_decl))
{
if (DECL_INITIAL (lhs))
warning ("return value from function receives multiple initializations");
DECL_INITIAL (lhs) = newrhs;
}
}
else
{
/* Avoid warnings on enum bit fields. */

4
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,7 @@
2001-12-24 Nathan Sidwell <nathan@codesourcery.com>
* g++.dg/other/init2.C: New test.
2001-12-24 Richard Henderson <rth@redhat.com>
* gcc.dg/20011223-1.c: New.

49
gcc/testsuite/g++.dg/other/init2.C Normal file
View File

@ -0,0 +1,49 @@
// { dg-do run }
// Copyright (C) 2001 Free Software Foundation, Inc.
// Contributed by Nathan Sidwell 20 Dec 2001 <nathan@nathan@codesourcery.com>
// PR 160. Wrong code emitted for some reference initializers.
void Foo ()
{
}
int fail;
class C
{
public:
int m;
int &r;
C () ;
};
C::C ()
: m (1), r ((Foo (), m))
{
m = 10;
if (r != m)
fail = 1;
else if (&m != &r)
fail = 2;
}
int main ()
{
int m (1);
int &r ((Foo (),m));
m = 10;
if (r != m)
fail = 3;
else if (&r != &m)
fail = 4;
if (!fail)
{
C c;
}
return fail;
}