Hi!
As can be seen on the testcase, when array_expr is type dependent, assuming
it has non-NULL TREE_TYPE is just wrong, it can often have NULL type, and even
if not, blindly assuming it is a pointer or array type is also wrong.
So, like in many other spots in the C++ FE, for type dependent expressions
we want to create something which will survive until instantiation and can be
redone at that point.
Unfortunately, build_omp_array_section is called before we actually do any
kind of checking what array_expr really is, and on invalid code it can be e.g.
a TYPE_DECL on which type_dependent_expression_p ICEs (as can be seen on the
pr67522.C testcase). So, I've hacked this by checking it is not TYPE_DECL,
I hope a TYPE_P can't make it through there when we just lookup an identifier.
Anyway, this patch is not enough, we can ICE e.g. on __uint128_t[0:something]
during instantiation, so I think something needs to be done for this in pt.cc
as well.
Bootstrapped/regtested on x86_64-linux and i686-linux, committed to trunk.
2025-01-23 Jakub Jelinek <ja...@redhat.com>
PR c++/118590
* typeck.cc (build_omp_array_section): If array_expr is type dependent
or a TYPE_DECL, build OMP_ARRAY_SECTION with NULL type.
* g++.dg/goacc/pr118590.C: New test.
--- gcc/cp/typeck.cc.jj 2025-01-21 16:26:04.154690509 +0100
+++ gcc/cp/typeck.cc 2025-01-22 15:09:09.487161968 +0100
@@ -4867,6 +4867,11 @@ tree
build_omp_array_section (location_t loc, tree array_expr, tree index,
tree length)
{
+ if (TREE_CODE (array_expr) == TYPE_DECL
+ || type_dependent_expression_p (array_expr))
+ return build3_loc (loc, OMP_ARRAY_SECTION, NULL_TREE, array_expr, index,
+ length);
+
tree type = TREE_TYPE (array_expr);
gcc_assert (type);
type = non_reference (type);
--- gcc/testsuite/g++.dg/goacc/pr118590.C.jj 2025-01-22 16:11:29.167592421
+0100
+++ gcc/testsuite/g++.dg/goacc/pr118590.C 2025-01-22 16:09:53.901933174
+0100
@@ -0,0 +1,29 @@
+// PR c++/118590
+// { dg-do compile }
+
+template <typename T>
+struct A
+{
+ int z;
+};
+
+template <typename T, typename U>
+struct B
+{
+ char *w;
+ A<T> y;
+};
+
+template <typename T, typename U>
+void
+foo (B<T, U> &x)
+{
+ A<T> c = x.y;
+ #pragma acc enter data copyin(x.w[0 : c.z])
+}
+
+void
+bar (B<int, int> &x)
+{
+ foo (x);
+}
Jakub
