From aa11a9e0c178554220efd891a6e731932e89848a Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Sun, 29 Sep 2024 11:24:03 +0100
Subject: [PATCH] Fix error when work library has same name as entity. Fixes
 #991

---
 NEWS.md                 |  2 ++
 src/parse.c             | 36 ++++++++++--------------------------
 test/parse/issue991.vhd | 13 +++++++++++++
 test/test_parse.c       | 13 +++++++++++++
 4 files changed, 38 insertions(+), 26 deletions(-)
 create mode 100644 test/parse/issue991.vhd

diff --git a/NEWS.md b/NEWS.md
index 205b05107..d278aeb16 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,4 +1,6 @@
 ## Unreleased changes
+- Fixed an error when using the `work` library alias and the working
+  library has the same name as design unit being analysed (#991).
 
 ## Version 1.14.0 - 2024-09-22
 - Waiting on implicit `'stable` and `'quiet` signals now works
diff --git a/src/parse.c b/src/parse.c
index 8ad08b3e1..84f9b6f59 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -1567,27 +1567,6 @@ static tree_t ensure_labelled(tree_t t, ident_t label)
    return t;
 }
 
-static tree_t external_reference(tree_t t)
-{
-   switch (tree_kind(t)) {
-   case T_ENTITY:
-   case T_LIBRARY:
-   case T_ARCH:
-   case T_PACKAGE:
-   case T_PACK_INST:
-   case T_CONFIGURATION:
-      {
-         tree_t ref = tree_new(T_REF);
-         tree_set_loc(ref, CURRENT_LOC);
-         tree_set_ident(ref, tree_ident(t));
-         tree_set_ref(ref, t);
-         return ref;
-      }
-   default:
-      return t;
-   }
-}
-
 static tree_t select_decl(tree_t prefix, ident_t suffix, name_mask_t *mask)
 {
    ident_t qual = ident_prefix(tree_ident(prefix), suffix, '.');
@@ -3488,8 +3467,6 @@ static tree_t p_attribute_name(tree_t prefix)
       type   = tree_type(prefix);
    }
 
-   prefix = external_reference(prefix);
-
    tree_t t = tree_new(T_ATTR_REF);
    tree_set_name(t, prefix);
 
@@ -3570,7 +3547,7 @@ static tree_t p_selected_name(tree_t prefix, name_mask_t *mask)
       tree_t decl = tree_ref(prefix);
       const tree_kind_t kind = tree_kind(decl);
       if (kind == T_LIBRARY) {
-         ident_t unit_name = ident_prefix(tree_ident(decl), suffix, '.');
+         ident_t unit_name = ident_prefix(tree_ident(prefix), suffix, '.');
          tree_t unit = resolve_name(nametab, CURRENT_LOC, unit_name);
          if (unit == NULL) {
             tree_t dummy = tree_new(T_REF);
@@ -3579,8 +3556,15 @@ static tree_t p_selected_name(tree_t prefix, name_mask_t *mask)
             *mask |= N_ERROR;
             return dummy;
          }
-         else
-            return external_reference(unit);
+         else {
+            assert(is_design_unit(unit));
+
+            tree_t ref = tree_new(T_REF);
+            tree_set_loc(ref, CURRENT_LOC);
+            tree_set_ident(ref, unit_name);
+            tree_set_ref(ref, unit);
+            return ref;
+         }
       }
       else if (kind == T_GENERIC_DECL && tree_class(decl) == C_PACKAGE)
          return select_decl(tree_value(decl), suffix, mask);
diff --git a/test/parse/issue991.vhd b/test/parse/issue991.vhd
new file mode 100644
index 000000000..c76675245
--- /dev/null
+++ b/test/parse/issue991.vhd
@@ -0,0 +1,13 @@
+package pack is
+    type t_enum is (a, b, c);
+end package;
+
+-------------------------------------------------------------------------------
+
+entity issue991 is
+end entity;
+
+architecture test of issue991 is
+    constant c : work.pack.t_enum := work.pack.a;      -- OK
+begin
+end architecture;
diff --git a/test/test_parse.c b/test/test_parse.c
index 473d235e9..98e5e51e7 100644
--- a/test/test_parse.c
+++ b/test/test_parse.c
@@ -6897,6 +6897,18 @@ START_TEST(test_issue977)
 }
 END_TEST
 
+START_TEST(test_issue991)
+{
+   input_from_file(TESTDIR "/parse/issue991.vhd");
+
+   parse_and_check(T_PACKAGE, T_ENTITY, T_ARCH);
+
+   fail_unless(parse() == NULL);
+
+   fail_if_errors();
+}
+END_TEST
+
 Suite *get_parse_tests(void)
 {
    Suite *s = suite_create("parse");
@@ -7060,6 +7072,7 @@ Suite *get_parse_tests(void)
    tcase_add_test(tc_core, test_issue956);
    tcase_add_test(tc_core, test_issue961);
    tcase_add_test(tc_core, test_issue977);
+   tcase_add_test(tc_core, test_issue991);
    suite_add_tcase(s, tc_core);
 
    return s;