From 81d7228647e0bd17d4f4f0434b8ed410fe5f7497 Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Tue, 19 Oct 2021 06:07:45 -0400
Subject: [PATCH] bios-tables-test: don't disassemble empty files

A recommended way to populate new tables is to have an
empty expected file. In this case, attempts to disassemble
will fail but it is useful to disassemble the actual files.
Detect and skip decompile step in this case.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 tests/qtest/bios-tables-test.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/tests/qtest/bios-tables-test.c b/tests/qtest/bios-tables-test.c
index 6e21a650d2..798f68c737 100644
--- a/tests/qtest/bios-tables-test.c
+++ b/tests/qtest/bios-tables-test.c
@@ -271,19 +271,28 @@ static void dump_aml_files(test_data *data, bool rebuild)
     }
 }
 
+static bool create_tmp_asl(AcpiSdtTable *sdt)
+{
+    GError *error = NULL;
+    gint fd;
+
+    fd = g_file_open_tmp("asl-XXXXXX.dsl", &sdt->asl_file, &error);
+    g_assert_no_error(error);
+    close(fd);
+
+    return false;
+}
+
 static bool load_asl(GArray *sdts, AcpiSdtTable *sdt)
 {
     AcpiSdtTable *temp;
     GError *error = NULL;
     GString *command_line = g_string_new(iasl);
-    gint fd;
     gchar *out, *out_err;
     gboolean ret;
     int i;
 
-    fd = g_file_open_tmp("asl-XXXXXX.dsl", &sdt->asl_file, &error);
-    g_assert_no_error(error);
-    close(fd);
+    create_tmp_asl(sdt);
 
     /* build command line */
     g_string_append_printf(command_line, " -p %s ", sdt->asl_file);
@@ -463,11 +472,20 @@ static void test_acpi_asl(test_data *data)
         err = load_asl(data->tables, sdt);
         asl = normalize_asl(sdt->asl);
 
-        exp_err = load_asl(exp_data.tables, exp_sdt);
-        exp_asl = normalize_asl(exp_sdt->asl);
+        /*
+         * If expected file is empty - it's likely that it was a stub just
+         * created for step 1 above: we do want to decompile the actual one.
+         */
+        if (exp_sdt->aml_len) {
+            exp_err = load_asl(exp_data.tables, exp_sdt);
+            exp_asl = normalize_asl(exp_sdt->asl);
+        } else {
+            exp_err = create_tmp_asl(exp_sdt);
+            exp_asl = g_string_new("");
+        }
 
         /* TODO: check for warnings */
-        g_assert(!err || exp_err);
+        g_assert(!err || exp_err || !exp_sdt->aml_len);
 
         if (g_strcmp0(asl->str, exp_asl->str)) {
             sdt->tmp_files_retain = true;