[PATCH] Update array address space in c_build_qualified_type

[SenthilKumar.Selvaraj--- via Gcc-patches]

Hi,

  When c-typeck.cc:c_build_qualified_type builds an array type
  from its element type, it does not copy the address space of
  the element type to the array type itself. This is unlike
  tree.cc:build_array_type_1, which explicitly does

TYPE_ADDR_SPACE (t) = TYPE_ADDR_SPACE (elt_type);

  This causes the ICE described in
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86869.

struct S {
  char y[2];
};

extern const __memx  struct S *s;

extern void bar(const __memx void*);

void foo(void) {
  bar(&s->y);
}

  build_component_ref calls c_build_qualified_type, passing in the
  array type and quals including the address space (ADDR_SPACE_MEMX
  in this case). Because of this missing address space copy, the
  returned array type remains in the generic address space.  Later
  down the line, expand_expr_addr_expr detects the mismatch in
  address space/mode and tries to convert, and that leads to the
  ICE described in the bug.

  This patch sets the address space of the array type to that of the
  element type.

  Regression tests for avr look ok. Ok for trunk?

Regards
Senthil

        PR 86869

gcc/c/ChangeLog:

        * c-typeck.cc (c_build_qualified_type): Set
        TYPE_ADDR_SPACE for ARRAY_TYPE.

gcc/testsuite/ChangeLog:

        * gcc.target/avr/pr86869.c: New test.

diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 22e240a3c2a..d4ab1d1bd46 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -16284,6 +16284,7 @@ c_build_qualified_type (tree type, int type_quals, tree 
orig_qual_type,
 
          t = build_variant_type_copy (type);
          TREE_TYPE (t) = element_type;
+         TYPE_ADDR_SPACE (t) = TYPE_ADDR_SPACE (element_type);
 
           if (TYPE_STRUCTURAL_EQUALITY_P (element_type)
               || (domain && TYPE_STRUCTURAL_EQUALITY_P (domain)))
diff --git a/gcc/testsuite/gcc.target/avr/pr86869.c 
b/gcc/testsuite/gcc.target/avr/pr86869.c
new file mode 100644
index 00000000000..54cd984276e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/avr/pr86869.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99" } */
+
+extern void bar(const __memx void* p);
+
+struct S {
+  char y[2];
+};
+extern const __memx struct S *s;
+
+void foo(void) {
+  bar(&s->y);
+}