commit 10760eb60bfd8f5de38ff1194718851a3d0f9073
Author: Jason Merrill <jason@redhat.com>
Date: Tue Jan 13 07:45:03 2015 -0500
PR c++/64356
PR libstdc++/58777
* constexpr.c (cxx_eval_binary_expression): Don't VERIFY_CONSTANT
pointer expressions.
(cxx_eval_increment_expression): Likewise.
@@ -1616,10 +1616,15 @@ cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t,
tree lhs, rhs;
lhs = cxx_eval_constant_expression (ctx, orig_lhs, /*lval*/false,
non_constant_p, overflow_p);
- VERIFY_CONSTANT (lhs);
+ /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to
+ a local array in a constexpr function. */
+ bool ptr = POINTER_TYPE_P (TREE_TYPE (lhs));
+ if (!ptr)
+ VERIFY_CONSTANT (lhs);
rhs = cxx_eval_constant_expression (ctx, orig_rhs, /*lval*/false,
non_constant_p, overflow_p);
- VERIFY_CONSTANT (rhs);
+ if (!ptr)
+ VERIFY_CONSTANT (lhs);
location_t loc = EXPR_LOCATION (t);
enum tree_code code = TREE_CODE (t);
@@ -1634,7 +1639,8 @@ cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t,
}
else if (cxx_eval_check_shift_p (loc, ctx, code, type, lhs, rhs))
*non_constant_p = true;
- VERIFY_CONSTANT (r);
+ if (!ptr)
+ VERIFY_CONSTANT (lhs);
return r;
}
@@ -2704,7 +2710,11 @@ cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t,
tree val = rvalue (op);
val = cxx_eval_constant_expression (ctx, val, false,
non_constant_p, overflow_p);
- VERIFY_CONSTANT (val);
+ /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to
+ a local array in a constexpr function. */
+ bool ptr = POINTER_TYPE_P (TREE_TYPE (val));
+ if (!ptr)
+ VERIFY_CONSTANT (val);
/* The modified value. */
bool inc = (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR);
@@ -2719,7 +2729,8 @@ cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t,
}
else
mod = fold_build2 (inc ? PLUS_EXPR : MINUS_EXPR, type, val, offset);
- VERIFY_CONSTANT (mod);
+ if (!ptr)
+ VERIFY_CONSTANT (mod);
/* Storing the modified value. */
tree store = build2 (MODIFY_EXPR, type, op, mod);
new file mode 100644
@@ -0,0 +1,22 @@
+// PR c++/64356
+// { dg-do compile { target c++14 } }
+
+typedef unsigned long size_t;
+
+template<size_t N>
+constexpr size_t f(const char (&x)[N]) {
+ size_t s = 0;
+ for(size_t c : x)
+ s += c;
+ return s;
+}
+
+template<size_t N>
+constexpr size_t g(const char (&x)[N]) {
+ char y[N] = {0};
+ for(size_t i = 0; i < N; ++i)
+ y[i] = x[i];
+ return f(y);
+}
+
+constexpr auto x = g(__DATE__);
@@ -6,5 +6,5 @@ foo (int i)
int a[i] = { }; // { dg-error "forbids variable length" }
}
-constexpr int j = foo (1); // { dg-error "is not a constant expression" }
+constexpr int j = foo (1); // { dg-error "flows off the end" }
@@ -1,7 +1,4 @@
// { dg-options "-std=gnu++14" }
-// XFAIL pending resolution of PR libstdc++/58777
-// { dg-do compile { xfail *-*-* } }
-// { dg-excess-errors "" }
// Copyright (C) 2013-2015 Free Software Foundation, Inc.
//
@@ -1,7 +1,4 @@
// { dg-options "-std=gnu++14" }
-// XFAIL pending resolution of PR libstdc++/58777
-// { dg-do compile { xfail *-*-* } }
-// { dg-excess-errors "" }
// Copyright (C) 2013-2015 Free Software Foundation, Inc.
//
@@ -1,7 +1,4 @@
// { dg-options "-std=gnu++14" }
-// XFAIL pending resolution of PR libstdc++/58777
-// { dg-do compile { xfail *-*-* } }
-// { dg-excess-errors "" }
// Copyright (C) 2013-2015 Free Software Foundation, Inc.
//