Fix crash on array component with nonstandard index type

This is a regression present on mainline, 10 and 9 branches: the compiler
goes into an infinite recursion eventually exhausting the stack for the
declaration of a discriminated record type with an array component having
a discriminant as bound and an index type that is an enumeration type with
a non-standard representation clause.

gcc/ada/ChangeLog:
	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Array_Subtype>: Only
	create extra subtypes for discriminants if the RM size of the base
	type of the index type is lower than that of the index type.

gcc/testsuite/ChangeLog:
	* gnat.dg/specs/discr7.ads: New test.

diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c
index 8045fa5ff97242ff8c8a81a4ac0d4170f1c8721c..2b7392c62c0889a8e868a97c3918b72e1bcb1a03 100644 (file)
--- a/gcc/ada/gcc-interface/decl.c
+++ b/gcc/ada/gcc-interface/decl.c
@@ -2480,8 +2480,8 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
              tree gnu_base_orig_max = TYPE_MAX_VALUE (gnu_base_index_type);
              tree gnu_min, gnu_max, gnu_high;
 
-             /* We try to define subtypes for discriminants used as bounds
-                that are more restrictive than those declared by using the
+             /* We try to create subtypes for discriminants used as bounds
+                that are more restrictive than those declared, by using the
                 bounds of the index type of the base array type.  This will
                 make it possible to calculate the maximum size of the record
                 type more conservatively.  This may have already been done by
@@ -2489,8 +2489,8 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
                 there will be a conversion that needs to be removed first.  */
              if (CONTAINS_PLACEHOLDER_P (gnu_orig_min)
                  && TYPE_RM_SIZE (gnu_base_index_type)
-                 && !tree_int_cst_lt (TYPE_RM_SIZE (gnu_index_type),
-                                      TYPE_RM_SIZE (gnu_base_index_type)))
+                 && tree_int_cst_lt (TYPE_RM_SIZE (gnu_base_index_type),
+                                     TYPE_RM_SIZE (gnu_index_type)))
                {
                  gnu_orig_min = remove_conversions (gnu_orig_min, false);
                  TREE_TYPE (gnu_orig_min)
@@ -2501,8 +2501,8 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 
              if (CONTAINS_PLACEHOLDER_P (gnu_orig_max)
                  && TYPE_RM_SIZE (gnu_base_index_type)
-                 && !tree_int_cst_lt (TYPE_RM_SIZE (gnu_index_type),
-                                      TYPE_RM_SIZE (gnu_base_index_type)))
+                 && tree_int_cst_lt (TYPE_RM_SIZE (gnu_base_index_type),
+                                     TYPE_RM_SIZE (gnu_index_type)))
                {
                  gnu_orig_max = remove_conversions (gnu_orig_max, false);
                  TREE_TYPE (gnu_orig_max)

diff --git a/gcc/testsuite/gnat.dg/specs/discr7.ads b/gcc/testsuite/gnat.dg/specs/discr7.ads
new file mode 100644 (file)
index 0000000..ca35ced
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/specs/discr7.ads
@@ -0,0 +1,14 @@
+-- { dg-do compile }
+
+package Discr7 is
+
+  type Enum is (One, Two, Three);
+  for Enum use (One => 1, Two => 2, Three => 3);
+
+  type Arr is array (Integer range <>, Enum range <>) of Boolean;
+
+  type Rec (D : Integer) is record
+    A: Arr (1 .. D, Enum'Range);
+  end record;
+
+end Discr7;