Tested x86_64-pc-linux-gnu, applying to trunk.
-- 8< --
Normally we handle xvalue array subscripting with ARRAY_REF, but in this
case we weren't doing that because the operands were reversed. Handle that
case better.
PR c++/103185
gcc/cp/ChangeLog:
* typeck.cc (cp_build_array_ref): Handle swapped operands.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1z/array-prvalue2.C: New test.
* g++.dg/cpp1z/eval-order3.C: Test swapped operands.
---
gcc/cp/typeck.cc | 16 +++++++++++++---
gcc/testsuite/g++.dg/cpp1z/array-prvalue2.C | 5 +++++
gcc/testsuite/g++.dg/cpp1z/eval-order3.C | 5 +++++
3 files changed, 23 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1z/array-prvalue2.C
diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
index a6e2f4ee7da..1fe30fc7c48 100644
--- a/gcc/cp/typeck.cc
+++ b/gcc/cp/typeck.cc
@@ -3932,13 +3932,14 @@ cp_build_indirect_ref (location_t loc, tree ptr,
ref_operator errorstring,
If INDEX is of some user-defined type, it must be converted to
integer type. Otherwise, to make a compatible PLUS_EXPR, it
will inherit the type of the array, which will be some pointer type.
-
+
LOC is the location to use in building the array reference. */
tree
cp_build_array_ref (location_t loc, tree array, tree idx,
tsubst_flags_t complain)
{
+ tree first = NULL_TREE;
tree ret;
if (idx == 0)
@@ -3983,6 +3984,14 @@ cp_build_array_ref (location_t loc, tree array, tree idx,
bool non_lvalue = convert_vector_to_array_for_subscript (loc, &array, idx);
+ /* 0[array] */
+ if (TREE_CODE (TREE_TYPE (idx)) == ARRAY_TYPE)
+ {
+ std::swap (array, idx);
+ if (flag_strong_eval_order == 2 && TREE_SIDE_EFFECTS (array))
+ idx = first = save_expr (idx);
+ }
+
if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
{
tree rval, type;
@@ -4058,15 +4067,16 @@ cp_build_array_ref (location_t loc, tree array, tree
idx,
protected_set_expr_location (ret, loc);
if (non_lvalue)
ret = non_lvalue_loc (loc, ret);
+ if (first)
+ ret = build2_loc (loc, COMPOUND_EXPR, TREE_TYPE (ret), first, ret);
return ret;
}
{
tree ar = cp_default_conversion (array, complain);
tree ind = cp_default_conversion (idx, complain);
- tree first = NULL_TREE;
- if (flag_strong_eval_order == 2 && TREE_SIDE_EFFECTS (ind))
+ if (!first && flag_strong_eval_order == 2 && TREE_SIDE_EFFECTS (ind))
ar = first = save_expr (ar);
/* Put the integer in IND to simplify error checking. */
diff --git a/gcc/testsuite/g++.dg/cpp1z/array-prvalue2.C
b/gcc/testsuite/g++.dg/cpp1z/array-prvalue2.C
new file mode 100644
index 00000000000..60a038cfd16
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/array-prvalue2.C
@@ -0,0 +1,5 @@
+// PR c++/103185
+// { dg-do compile { target c++11 } }
+
+using intarr = int[];
+static_assert(__is_same(decltype(0[intarr{0}]), int&&), "");
diff --git a/gcc/testsuite/g++.dg/cpp1z/eval-order3.C
b/gcc/testsuite/g++.dg/cpp1z/eval-order3.C
index 5773591d49f..897cdef7483 100644
--- a/gcc/testsuite/g++.dg/cpp1z/eval-order3.C
+++ b/gcc/testsuite/g++.dg/cpp1z/eval-order3.C
@@ -166,6 +166,11 @@ void g()
ip(24)[f(25)-25] = 0;
last=0;
+ // even with swapped operands
+ (f(20)-20)[afn(21)].memfn(f(22),23);
+ (f(24)-24)[ip(25)] = 0;
+ last=0;
+
// a << b
aref(24) << f(25);
iref(26) << f(27);
base-commit: a3ff76278efe006dc0b50249c8e5baf565bff56b
--
2.39.3
