From f96e48995e95d3f13c841a9c0970e747aa3352c7 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Sat, 18 Feb 2023 21:48:45 +0000
Subject: [PATCH] Ignore interpreter iteration limit when initialising a
 package

---
 src/jit/jit-interp.c      | 15 +++++++++--
 test/regress/link4.vhd    | 55 +++++++++++++++++++++++++++++++++++++++
 test/regress/testlist.txt |  1 +
 3 files changed, 69 insertions(+), 2 deletions(-)
 create mode 100644 test/regress/link4.vhd

diff --git a/src/jit/jit-interp.c b/src/jit/jit-interp.c
index a4cbcfd3..99a942d4 100644
--- a/src/jit/jit-interp.c
+++ b/src/jit/jit-interp.c
@@ -554,8 +554,19 @@ static void interp_branch_to(jit_interp_t *state, jit_value_t label)
    const int target = interp_get_value(state, label).integer;
    if (state->backedge > 0 && target < state->pc) {
       // Limit the number of loop iterations in bounded mode
-      if (--(state->backedge) == 0)
-         jit_msg(NULL, DIAG_FATAL, "maximum iteration limit reached");
+      if (--(state->backedge) == 0) {
+         bool safe_to_abort = true;
+         for (jit_anchor_t *a = state->anchor; a; a = a->caller) {
+            if (a->func->privdata != MPTR_INVALID) {
+               // We might be in the middle of initialising a package so
+               // cannot abandon execution here
+               safe_to_abort = false;
+            }
+         }
+
+         if (safe_to_abort)
+            jit_msg(NULL, DIAG_FATAL, "maximum iteration limit reached");
+      }
    }
 
    state->pc = target;
diff --git a/test/regress/link4.vhd b/test/regress/link4.vhd
new file mode 100644
index 00000000..1013b536
--- /dev/null
+++ b/test/regress/link4.vhd
@@ -0,0 +1,55 @@
+package pack is
+
+    type int_vec is array (natural range <>) of integer;
+
+    type rec is record
+        data : int_vec(1 to 100);
+    end record;
+
+    impure function make_rec return rec;
+
+    constant r : rec := make_rec;
+    constant s : string := "hello";
+
+    function get_string return string;
+
+end package;
+
+package body pack is
+
+    impure function make_rec return rec is
+        variable r : rec;
+    begin
+        for i in 1 to 100 loop
+            for j in 1 to 100 loop
+                r.data(j) := r.data(j) + 1;
+            end loop;
+        end loop;
+        return r;
+    end function;
+
+    function get_string return string is
+    begin
+        return s;
+    end function;
+
+end package body;
+
+-------------------------------------------------------------------------------
+
+entity link4 is
+end entity;
+
+use work.pack.all;
+
+architecture test of link4 is
+begin
+
+    p1: process is
+    begin
+        assert get_string = s;  -- OK
+        assert get_string = s;  -- OK (failed spuriously)
+        wait;
+    end process;
+
+end architecture;
diff --git a/test/regress/testlist.txt b/test/regress/testlist.txt
index 0d798e74..fbe256dd 100644
--- a/test/regress/testlist.txt
+++ b/test/regress/testlist.txt
@@ -714,3 +714,4 @@ issue603        normal
 issue609        normal
 issue618        normal,gA='1',gB='0'
 issue615        normal,gold,2008
+link4           normal
-- 
2.39.2