Expected table change is then handled like this:
1. add table to diff allowed list
2. change generating code (can be combined with 1)
3. maintainer runs a script to update expected +
   blows away allowed diff list

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

So I got tired of manual "remember to update AML files"
reminders. With this an AML diff asserts unless it's
explicitly allowed.

Comments?

 tests/bios-tables-test-allowed-diff.h |  1 +
 tests/bios-tables-test.c              | 20 +++++++++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 tests/bios-tables-test-allowed-diff.h

diff --git a/tests/bios-tables-test-allowed-diff.h b/tests/bios-tables-test-allowed-diff.h
new file mode 100644
index 0000000000..dfb8523c8b
--- /dev/null
+++ b/tests/bios-tables-test-allowed-diff.h
@@ -0,0 +1 @@
+/* List of comma-separated changed AML files to ignore */
diff --git a/tests/bios-tables-test.c b/tests/bios-tables-test.c
index 11e07be093..93db1a7265 100644
--- a/tests/bios-tables-test.c
+++ b/tests/bios-tables-test.c
@@ -342,6 +342,23 @@ try_again:
     return exp_tables;
 }
 
+static bool test_acpi_find_diff_allowed(AcpiSdtTable *sdt)
+{
+    const gchar *allowed_diff_file[] = {
+#include "bios-tables-test-allowed-diff.h"
+        NULL
+    };
+    int offset = strlen(data_dir) + 1;
+    const gchar **f;
+
+    for (f = allowed_diff_file; *f; ++f) {
+        if (!g_strcmp0(sdt->aml_file + offset, *f)) {
+            return true;
+        }
+    }
+    return false;
+}
+
 /* test the list of tables in @data->tables against reference tables */
 static void test_acpi_asl(test_data *data)
 {
@@ -396,7 +413,8 @@ static void test_acpi_asl(test_data *data)
                             "see ASL difference.");
                     }
                 }
-          }
+            }
+            g_assert(test_acpi_find_diff_allowed(sdt));
         }
         g_string_free(asl, true);
         g_string_free(exp_asl, true);
-- 
MST