From b46f2e5c0103d4b7407b69195995388f893ffc42 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Mon, 12 Feb 2024 22:37:30 +0000
Subject: [PATCH] Fix crash with external name and component declarations

---
 src/elab.c                | 14 +++++++--
 src/jit/jit-irgen.c       |  2 +-
 src/lower.c               | 13 +++++---
 test/regress/ename7.vhd   | 62 +++++++++++++++++++++++++++++++++++++++
 test/regress/testlist.txt |  1 +
 5 files changed, 84 insertions(+), 8 deletions(-)
 create mode 100644 test/regress/ename7.vhd

diff --git a/src/elab.c b/src/elab.c
index 72400984..a2504613 100644
--- a/src/elab.c
+++ b/src/elab.c
@@ -2036,6 +2036,17 @@ tree_t elab_external_name(tree_t name, tree_t root, ident_t *path)
          return NULL;
       }
 
+      tree_t hier = tree_decl(where, 0);
+      assert(tree_kind(hier) == T_HIER);
+
+      if (tree_subkind(hier) == T_COMPONENT) {
+         // Skip over implicit block for component declaration
+         where = tree_stmt(where, 0);
+         assert(tree_kind(where) == T_BLOCK);
+         hier = tree_decl(where, 0);
+         *path = ident_prefix(*path, tree_ident(where), '.');
+      }
+
       const int nstmts = tree_stmts(where);
       for (int i = 0; i < nstmts; i++) {
          tree_t s = tree_stmt(where, i);
@@ -2056,9 +2067,6 @@ tree_t elab_external_name(tree_t name, tree_t root, ident_t *path)
                    istr(tree_ident(where)));
 
          if (tree_kind(where) == T_BLOCK) {
-            tree_t hier = tree_decl(where, 0);
-            assert(tree_kind(hier) == T_HIER);
-
             tree_t unit = tree_ref(hier);
             const int nstmts = tree_stmts(unit);
             for (int i = 0; i < nstmts; i++) {
diff --git a/src/jit/jit-irgen.c b/src/jit/jit-irgen.c
index aad0f8e2..bc12358d 100644
--- a/src/jit/jit-irgen.c
+++ b/src/jit/jit-irgen.c
@@ -2567,7 +2567,7 @@ static void irgen_op_link_var(jit_irgen_t *g, int op)
          break;
    }
 
-   if (tab == NULL)
+   if (tab == f->linktab + f->nvars)
       fatal_trace("variable %s not found in unit %s", istr(var_name),
                   istr(unit_name));
 
diff --git a/src/lower.c b/src/lower.c
index b0865efb..86a944c8 100644
--- a/src/lower.c
+++ b/src/lower.c
@@ -3145,10 +3145,15 @@ static vcode_reg_t lower_external_name(lower_unit_t *lu, tree_t ref)
          }
 
          for (lower_unit_t *it = lu; it; it = it->parent) {
-            if (is_concurrent_block(it->container) && caret-- == 0) {
-               root = it->container;
-               path = it->name;
-               break;
+            if (is_concurrent_block(it->container)) {
+               tree_t hier = tree_decl(it->container, 0);
+               if (tree_subkind(hier) == T_COMPONENT)
+                  continue;   // Skip over implicit block for component
+               else if (caret-- == 0) {
+                  root = it->container;
+                  path = it->name;
+                  break;
+               }
             }
          }
       }
diff --git a/test/regress/ename7.vhd b/test/regress/ename7.vhd
new file mode 100644
index 00000000..cc8fa3ab
--- /dev/null
+++ b/test/regress/ename7.vhd
@@ -0,0 +1,62 @@
+entity sub1 is
+end entity;
+
+architecture test of sub1 is
+    signal t : natural;
+begin
+
+    p1: process is
+        alias s is <<signal ^.s : natural>>;
+    begin
+        s <= 5;
+        wait for 0 ns;
+        assert t = 42;
+        wait;
+    end process;
+
+end architecture;
+
+-------------------------------------------------------------------------------
+
+entity sub2 is
+end entity;
+
+architecture test of sub2 is
+begin
+
+    p2: process is
+        alias t is <<signal ^.u1.t : natural>>;
+    begin
+        t <= 42;
+        wait;
+    end process;
+
+end architecture;
+
+-------------------------------------------------------------------------------
+
+entity ename7 is
+end entity;
+
+architecture test of ename7 is
+    signal s : natural;
+
+    component sub1 is
+    end component;
+
+    component sub2 is
+    end component;
+begin
+
+    u1: component sub1;
+    u2: component sub2;
+
+    p3: process is
+    begin
+        assert s = 0;
+        wait for 0 ns;
+        assert s = 5;
+        wait;
+    end process;
+
+end architecture;
diff --git a/test/regress/testlist.txt b/test/regress/testlist.txt
index 1a7c1d79..58b14291 100644
--- a/test/regress/testlist.txt
+++ b/test/regress/testlist.txt
@@ -938,3 +938,4 @@ wave9           wave
 wave10          wave
 driver20        normal
 driver21        fail,gold
+ename7          normal,2008
-- 
2.39.2