From 36e22885e9b65ad293086cd57b578474857bad20 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Thu, 18 Jan 2024 11:29:57 +0000
Subject: [PATCH] Fix error getting resolved value of array-of-record signal

Fixes #839
---
 src/lower.c               | 33 +++++++++------------------------
 test/regress/issue839.vhd | 25 +++++++++++++++++++++++++
 test/regress/testlist.txt |  1 +
 3 files changed, 35 insertions(+), 24 deletions(-)
 create mode 100644 test/regress/issue839.vhd

diff --git a/src/lower.c b/src/lower.c
index 910baa75..d4cbdd46 100644
--- a/src/lower.c
+++ b/src/lower.c
@@ -3204,17 +3204,6 @@ static vcode_reg_t lower_external_name(lower_unit_t *lu, tree_t ref)
       return result_reg;
 }
 
-static type_t lower_base_type(type_t type)
-{
-   for (type_t base; type_kind(type) == T_SUBTYPE; type = base) {
-      base = type_base(type);
-      if (type_ident(base) == type_ident(type))
-         break;   // Subtype created for constrained array definition
-   }
-
-   return type;
-}
-
 static vcode_reg_t lower_resolved(lower_unit_t *lu, type_t type,
                                   vcode_reg_t reg)
 {
@@ -3239,9 +3228,8 @@ static vcode_reg_t lower_resolved(lower_unit_t *lu, type_t type,
       // Use a helper function to convert a record signal into a record
       // containing the resolved values
 
-      type_t base = lower_base_type(type);
-      ident_t helper_func =
-         ident_prefix(type_ident(base), ident_new("resolved"), '$');
+      ident_t base_id = type_ident(type_base_recur(type));
+      ident_t helper_func = ident_prefix(base_id, ident_new("resolved"), '$');
 
       vcode_reg_t arg_reg = reg;
       if (type_is_array(type)) {
@@ -3251,7 +3239,7 @@ static vcode_reg_t lower_resolved(lower_unit_t *lu, type_t type,
             arg_reg = lower_wrap(lu, type, reg);
       }
 
-      vcode_type_t vrtype = lower_func_result_type(base);
+      vcode_type_t vrtype = lower_func_result_type(type);
 
       vcode_reg_t args[] = { lower_context_for_call(lu, helper_func), arg_reg };
       return emit_fcall(helper_func, vrtype, vrtype, VCODE_CC_VHDL, args, 2);
@@ -4483,9 +4471,8 @@ static void lower_new_record(lower_unit_t *lu, type_t type,
    else if (type_const_bounds(type))
       emit_copy(dst_ptr, src_ptr, VCODE_INVALID_REG);
    else {
-      type_t base = lower_base_type(type);
-      ident_t helper_func =
-         ident_prefix(type_ident(base), ident_new("new"), '$');
+      ident_t base_id = type_ident(type_base_recur(type));
+      ident_t helper_func = ident_prefix(base_id, ident_new("new"), '$');
 
       vcode_reg_t args[] = {
          lower_context_for_call(lu, helper_func),
@@ -5925,9 +5912,8 @@ static void lower_copy_record(lower_unit_t *lu, type_t type,
    else if (lower_trivially_copyable(type))
       emit_copy(dst_ptr, src_ptr, VCODE_INVALID_REG);
    else {
-      type_t base = lower_base_type(type);
-      ident_t helper_func =
-         ident_prefix(type_ident(base), ident_new("copy"), '$');
+      ident_t base_id = type_ident(type_base_recur(type));
+      ident_t helper_func = ident_prefix(base_id, ident_new("copy"), '$');
 
       vcode_reg_t args[] = {
          lower_context_for_call(lu, helper_func),
@@ -5957,9 +5943,8 @@ static void lower_copy_array(lower_unit_t *lu, type_t dst_type, type_t src_type,
       emit_copy(dst_data, src_data, count_reg);
    }
    else {
-      type_t base = lower_base_type(dst_type);
-      ident_t helper_func =
-         ident_prefix(type_ident(base), ident_new("copy"), '$');
+      ident_t base_id = type_ident(type_base_recur(dst_type));
+      ident_t helper_func = ident_prefix(base_id, ident_new("copy"), '$');
 
       assert(vcode_reg_kind(dst_array) == VCODE_TYPE_UARRAY);
       assert(vcode_reg_kind(src_array) == VCODE_TYPE_UARRAY);
diff --git a/test/regress/issue839.vhd b/test/regress/issue839.vhd
new file mode 100644
index 00000000..a945d35b
--- /dev/null
+++ b/test/regress/issue839.vhd
@@ -0,0 +1,25 @@
+entity issue839 is
+end entity;
+
+architecture test of issue839 is
+    type t_rec is record
+        f : integer;
+    end record;
+
+    type t_array is array (natural range <>) of t_rec;
+    subtype t_sub is t_array;
+
+    signal s : t_sub(1 to 2);
+begin
+
+    check: process is
+    begin
+        -- This would call the wrong helper function
+        assert s = (1 to 2 => (f => integer'left));
+        s(2).f <= 6;
+        wait for 0 ns;
+        assert s(2) = (f => 6);
+        wait;
+    end process;
+
+end architecture;
diff --git a/test/regress/testlist.txt b/test/regress/testlist.txt
index e11b2d93..f61b2a94 100644
--- a/test/regress/testlist.txt
+++ b/test/regress/testlist.txt
@@ -917,3 +917,4 @@ issue824        normal
 issue825        normal
 issue826        normal,2008
 issue827        normal,2008
+issue839        normal
-- 
2.39.2