From: Eric Botcazou <ebotca...@adacore.come> Unlike for 'Access or 'Unchecked_Access, the Attribute_to_gnu routine passes ATTR_ADDR_EXPR to build_unary_op for 'Unrestricted_Access, which causes the processing done in build_unary_op to flatten the reference, in particular to remove all intermediate (view) conversions, which may be problematic for the SUBSTITUTE_PLACEHOLDER_IN_EXPR machinery.
gcc/ada/ChangeLog: * gcc-interface/trans.cc (Attribute_to_gnu) <Attr_Access>: Do not pass ATTR_ADDR_EXPR to build_unary_op for 'Unrestricted_Access. Tested on x86_64-pc-linux-gnu, committed on master. --- gcc/ada/gcc-interface/trans.cc | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/gcc/ada/gcc-interface/trans.cc b/gcc/ada/gcc-interface/trans.cc index 5d971c1681d..3aa41253d74 100644 --- a/gcc/ada/gcc-interface/trans.cc +++ b/gcc/ada/gcc-interface/trans.cc @@ -1840,10 +1840,15 @@ Attribute_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, gcc_assert (TREE_CODE (gnu_prefix) != TYPE_DECL); gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* We used to pass ATTR_ADDR_EXPR for Attr_Unrestricted_Access too, but + the processing done in build_unary_op for it flattens the reference, + in particular removes all intermediate (view) conversions, which may + cause SUBSTITUTE_PLACEHOLDER_IN_EXPR to fail to substitute in the + bounds of a fat pointer returned for Attr_Unrestricted_Access. */ gnu_result - = build_unary_op (((attribute == Attr_Address - || attribute == Attr_Unrestricted_Access) - && !Must_Be_Byte_Aligned (gnat_node)) + = build_unary_op (attribute == Attr_Address + && !Must_Be_Byte_Aligned (gnat_node) ? ATTR_ADDR_EXPR : ADDR_EXPR, gnu_result_type, gnu_prefix); -- 2.43.0