------- Additional Comments From aoliva at gcc dot gnu dot org 2005-03-06
07:29 -------
Subject: Re: [PR c++/20103] failure to gimplify constructors for addressable
types
On Mar 5, 2005, Mark Mitchell <[EMAIL PROTECTED]> wrote:
> Alexandre Oliva wrote:
>> Testing now. I was a bit surprised that the casts to (const B&)
>> weren't reported as faulty, but didn't check the standard on it.
> I'd have to check the rules -- but I'm sure it's not a problem with
> your patch. Either its correct, or an already-present bug.
>> Ok
>> to install if testing passes?
> Yes.
Unfortunately, g++.dg/template/ctor1.C and g++.dg/template/complit1.C
regressed. As it turned out, complit1.C was in error, and had to be
adjusted to match g++.dg/ext/complit1.C, since the only significant
difference between them was that one of them had the compound-literal
within a ctor of a template class.
ctor1.C, however, exposed a failure to handle TARGET_EXPRs while
instantiating templates. So I extended the tsubst machinery to do it,
and now ctor1.C passes again.
I also noticed that the patch fixes g++.old-deja/g++.oliva/expr2.C,
yay!
Here's the latest version of the patch, that so far passed make -C gcc
all check-g++. Full bootstrap and regtest on x86_64-linux-gnu still
pending. Ok to install if it passes?
Index: gcc/cp/ChangeLog
from Alexandre Oliva <[EMAIL PROTECTED]>
PR c++/20103
* semantics.c (finish_compound_literal): Wrap it in a
target_expr.
* pt.c (tsubst_copy_and_build): Handle TARGET_EXPR.
Index: gcc/cp/semantics.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/semantics.c,v
retrieving revision 1.463
diff -u -p -r1.463 semantics.c
--- gcc/cp/semantics.c 23 Feb 2005 05:30:48 -0000 1.463
+++ gcc/cp/semantics.c 6 Mar 2005 07:12:11 -0000
@@ -1996,7 +1996,9 @@ finish_compound_literal (tree type, tree
complete_array_type (type, compound_literal, 1);
}
- return compound_literal;
+ /* A compound-literal is an lvalue in C, but is it going to be
+ in ISO C++? Assume it's an rvalue for now. */
+ return get_target_expr (compound_literal);
}
/* Return the declaration for the function-name variable indicated by
Index: gcc/cp/pt.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/pt.c,v
retrieving revision 1.978
diff -u -p -r1.978 pt.c
--- gcc/cp/pt.c 21 Feb 2005 23:12:26 -0000 1.978
+++ gcc/cp/pt.c 6 Mar 2005 07:12:19 -0000
@@ -8744,6 +8744,26 @@ tsubst_copy_and_build (tree t,
return build_throw
(RECUR (TREE_OPERAND (t, 0)));
+ case TARGET_EXPR:
+ {
+ tree r = tsubst_copy (t, args, complain, in_decl);
+
+ TREE_TYPE (r) = RECUR (TREE_TYPE (t));
+ TARGET_EXPR_SLOT (r) = RECUR (TARGET_EXPR_SLOT (t));
+ TARGET_EXPR_INITIAL (r) = RECUR (TARGET_EXPR_INITIAL (t));
+ TARGET_EXPR_CLEANUP (r) = RECUR (TARGET_EXPR_CLEANUP (t));
+
+ if (TREE_TYPE (TARGET_EXPR_SLOT (t))
+ == TREE_TYPE (TARGET_EXPR_INITIAL (t)))
+ TREE_TYPE (TARGET_EXPR_SLOT (r)) =
+ TREE_TYPE (TARGET_EXPR_INITIAL (r));
+
+ if (TREE_TYPE (t) == TREE_TYPE (TARGET_EXPR_SLOT (t)))
+ TREE_TYPE (r) = TREE_TYPE (TARGET_EXPR_SLOT (r));
+
+ return r;
+ }
+
case CONSTRUCTOR:
{
tree r;
Index: gcc/testsuite/ChangeLog
from Alexandre Oliva <[EMAIL PROTECTED]>
PR c++/20103
* g++.dg/tree-ssa/pr20103.C: New.
* g++.dg/template/complit1.C: Expect error like ext/complit1.C.
Index: gcc/testsuite/g++.dg/tree-ssa/pr20103.C
===================================================================
RCS file: gcc/testsuite/g++.dg/tree-ssa/pr20103.C
diff -N gcc/testsuite/g++.dg/tree-ssa/pr20103.C
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ gcc/testsuite/g++.dg/tree-ssa/pr20103.C 6 Mar 2005 07:12:35 -0000
@@ -0,0 +1,59 @@
+// PR c++/20103
+
+// { dg-do compile }
+
+// { dg-options "" }
+
+// Gimplification used to fail for (B){x}, because create_tmp_var
+// required a non-addressable type, and we didn't wrap the constructor
+// in a target_expr, ensuring it's moved to a separate decl.
+
+// Whether it is an lvalue, like in C, or an rvalue, is up to the ISO
+// C++ Commitete to decide in the second version of the C++ Standard.
+// We're going with rvalues for now.
+
+struct A
+{
+ A(const A&);
+};
+
+struct B
+{
+ A a;
+};
+
+void foo(B);
+void bar(B&); // { dg-error "in passing argument" }
+void bac(const B&);
+void bap(const B*);
+
+void baz(A &x)
+{
+ foo ((B){x});
+ bar ((B){x}); // { dg-error "non-const reference" }
+ bac ((B){x});
+ bap (&(B){x}); // { dg-error "address of temporary" }
+
+ foo ((const B&)(B){x});
+ bar ((B&)(B){x}); // { dg-error "invalid cast" }
+ bac ((const B&)(B){x});
+ bap (&(const B&)(B){x});
+}
+
+template <typename T, typename U>
+void baz(T &x)
+{
+ foo ((U){x});
+ bar ((U){x}); // { dg-error "non-const reference" }
+ bac ((U){x});
+ bap (&(U){x}); // { dg-error "address of temporary" }
+
+ foo ((const U&)(U){x});
+ bar ((U&)(U){x}); // { dg-error "invalid cast" }
+ bac ((const U&)(U){x});
+ bap (&(const U&)(U){x});
+}
+
+void bazT(A &x) {
+ baz<A,B>(x);
+}
Index: gcc/testsuite/g++.dg/template/complit1.C
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/g++.dg/template/complit1.C,v
retrieving revision 1.3
diff -u -p -r1.3 complit1.C
--- gcc/testsuite/g++.dg/template/complit1.C 28 Dec 2002 07:48:08 -0000 1.3
+++ gcc/testsuite/g++.dg/template/complit1.C 6 Mar 2005 07:12:35 -0000
@@ -6,6 +6,6 @@ template <int D> struct C {
};
template<int D>
-C<D>::C() : d((int[]){1,2,3}) {}
+C<D>::C() : d((int[]){1,2,3}) {} // { dg-error "assignment of arrays" }
-template class C<1>;
+template class C<1>; // { dg-error "instantiated from" }
Index: gcc/testsuite/g++.old-deja/g++.oliva/ChangeLog
from Alexandre Oliva <[EMAIL PROTECTED]>
PR c++/20103
* expr2.C: Fixed.
Index: gcc/testsuite/g++.old-deja/g++.oliva/expr2.C
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/g++.old-deja/g++.oliva/expr2.C,v
retrieving revision 1.5
diff -u -p -r1.5 expr2.C
--- gcc/testsuite/g++.old-deja/g++.oliva/expr2.C 1 May 2003 02:02:47 -0000 1.5
+++ gcc/testsuite/g++.old-deja/g++.oliva/expr2.C 6 Mar 2005 07:12:35 -0000
@@ -1,4 +1,4 @@
-// { dg-do run { xfail *-*-* } }
+// { dg-do run }
// Copyright (C) 2000 Free Software Foundation
--
Alexandre Oliva http://www.ic.unicamp.br/~oliva/
Red Hat Compiler Engineer [EMAIL PROTECTED], gcc.gnu.org}
Free Software Evangelist [EMAIL PROTECTED], gnu.org}
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20103
