Fix another ICE with C++ addressable bitsize 0 return value (PR c++/82159)

Message ID 20171011205432.GN14653@tucnak
State New
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  • Fix another ICE with C++ addressable bitsize 0 return value (PR c++/82159)
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Commit Message

Jakub Jelinek Oct. 11, 2017, 8:54 p.m.
Hi!

Another case where we ICE because we optimize away store to bitsize 0
addressable object from call.  We can't optimize them away, otherwise
we'd try to create the temporaries again and fail to do so.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?

2017-10-11  Jakub Jelinek  <jakub@redhat.com>

	PR c++/82159
	* expr.c (store_field): Don't optimize away bitsize == 0 store
	from CALL_EXPR with addressable return type.

	* g++.dg/opt/pr82159-2.C: New test.


	Jakub

Comments

Jason Merrill Oct. 12, 2017, 5:25 a.m. | #1
OK.

On Wed, Oct 11, 2017 at 4:54 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> Another case where we ICE because we optimize away store to bitsize 0
> addressable object from call.  We can't optimize them away, otherwise
> we'd try to create the temporaries again and fail to do so.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> trunk?
>
> 2017-10-11  Jakub Jelinek  <jakub@redhat.com>
>
>         PR c++/82159
>         * expr.c (store_field): Don't optimize away bitsize == 0 store
>         from CALL_EXPR with addressable return type.
>
>         * g++.dg/opt/pr82159-2.C: New test.
>
> --- gcc/expr.c.jj       2017-10-10 22:04:06.000000000 +0200
> +++ gcc/expr.c  2017-10-11 16:48:45.428536126 +0200
> @@ -6749,8 +6749,11 @@ store_field (rtx target, HOST_WIDE_INT b
>      return const0_rtx;
>
>    /* If we have nothing to store, do nothing unless the expression has
> -     side-effects.  */
> -  if (bitsize == 0)
> +     side-effects.  Don't do that for zero sized addressable lhs of
> +     calls.  */
> +  if (bitsize == 0
> +      && (!TREE_ADDRESSABLE (TREE_TYPE (exp))
> +         || TREE_CODE (exp) != CALL_EXPR))
>      return expand_expr (exp, const0_rtx, VOIDmode, EXPAND_NORMAL);
>
>    if (GET_CODE (target) == CONCAT)
> --- gcc/testsuite/g++.dg/opt/pr82159-2.C.jj     2017-10-11 17:27:18.050861346 +0200
> +++ gcc/testsuite/g++.dg/opt/pr82159-2.C        2017-10-11 17:27:27.081753330 +0200
> @@ -0,0 +1,65 @@
> +// PR c++/82159
> +// { dg-do compile }
> +// { dg-options "" }
> +
> +template <typename T> struct D { T e; };
> +struct F : D<int[0]> {
> +  F(const F &);
> +};
> +struct G : F {
> +  template <class T> G operator-(T);
> +};
> +template <class T> struct I {
> +  typedef typename T::template J<I> ak;
> +};
> +template <class T> struct K { typename I<T>::ak an; };
> +struct H {
> +  G l;
> +};
> +struct C {
> +  ~C();
> +};
> +template <class T> struct M : T {
> +  template <typename U, typename V> M(U, V);
> +  H h;
> +  virtual void foo() { T::bar(&h); }
> +};
> +template <int, typename> class A;
> +template <class> struct B {
> +  typedef int BT;
> +  struct BC {};
> +  template <class T> struct BD {
> +    G g;
> +    BD(BT, T n) : g(n.l - 0) {}
> +  };
> +  B(BT, BC);
> +};
> +template <typename> struct O;
> +template <int T, typename U>
> +struct O<B<A<T, U> > > : public B<A<T, U> >::BC {};
> +struct L : B<A<2, double> > {
> +  struct P : C {
> +    void bar(H *x) {
> +      BT a;
> +      BD<H>(a, *x);
> +    }
> +  };
> +  template <typename U, typename V> L(U x, V n) : B(x, n) {}
> +  int ll;
> +  virtual int baz() { M<P>(this, ll); }
> +};
> +template <typename> class Q {
> +  O<B<A<2, double> > > q;
> +  virtual L baz() { L(0, q); }
> +};
> +template <template <class> class T> struct R {
> +  R() { T<int>(); }
> +};
> +struct S {
> +  template <class> class J : R<Q> {};
> +};
> +void foo() { K<S> c; }
> +
> +int main() {
> +  return 0;
> +}
>
>         Jakub

Patch

--- gcc/expr.c.jj	2017-10-10 22:04:06.000000000 +0200
+++ gcc/expr.c	2017-10-11 16:48:45.428536126 +0200
@@ -6749,8 +6749,11 @@  store_field (rtx target, HOST_WIDE_INT b
     return const0_rtx;
 
   /* If we have nothing to store, do nothing unless the expression has
-     side-effects.  */
-  if (bitsize == 0)
+     side-effects.  Don't do that for zero sized addressable lhs of
+     calls.  */
+  if (bitsize == 0
+      && (!TREE_ADDRESSABLE (TREE_TYPE (exp))
+	  || TREE_CODE (exp) != CALL_EXPR))
     return expand_expr (exp, const0_rtx, VOIDmode, EXPAND_NORMAL);
 
   if (GET_CODE (target) == CONCAT)
--- gcc/testsuite/g++.dg/opt/pr82159-2.C.jj	2017-10-11 17:27:18.050861346 +0200
+++ gcc/testsuite/g++.dg/opt/pr82159-2.C	2017-10-11 17:27:27.081753330 +0200
@@ -0,0 +1,65 @@ 
+// PR c++/82159
+// { dg-do compile }
+// { dg-options "" }
+
+template <typename T> struct D { T e; };
+struct F : D<int[0]> {
+  F(const F &);
+};
+struct G : F {
+  template <class T> G operator-(T);
+};
+template <class T> struct I {
+  typedef typename T::template J<I> ak;
+};
+template <class T> struct K { typename I<T>::ak an; };
+struct H {
+  G l;
+};
+struct C {
+  ~C();
+};
+template <class T> struct M : T {
+  template <typename U, typename V> M(U, V);
+  H h;
+  virtual void foo() { T::bar(&h); }
+};
+template <int, typename> class A;
+template <class> struct B {
+  typedef int BT;
+  struct BC {};
+  template <class T> struct BD {
+    G g;
+    BD(BT, T n) : g(n.l - 0) {}
+  };
+  B(BT, BC);
+};
+template <typename> struct O;
+template <int T, typename U>
+struct O<B<A<T, U> > > : public B<A<T, U> >::BC {};
+struct L : B<A<2, double> > {
+  struct P : C {
+    void bar(H *x) {
+      BT a;
+      BD<H>(a, *x);
+    }
+  };
+  template <typename U, typename V> L(U x, V n) : B(x, n) {}
+  int ll;
+  virtual int baz() { M<P>(this, ll); }
+};
+template <typename> class Q {
+  O<B<A<2, double> > > q;
+  virtual L baz() { L(0, q); }
+};
+template <template <class> class T> struct R {
+  R() { T<int>(); }
+};
+struct S {
+  template <class> class J : R<Q> {};
+};
+void foo() { K<S> c; }
+
+int main() {
+  return 0;
+}