binman: Allow writing a map file when something goes wrong

When we get a problem like overlapping regions it is sometimes hard to
figure what what is going on. At present we don't write the map file in
this case. However the file does provide useful information.

Catch any packing errors and write a map file (if enabled with -m) to aid
debugging.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/binman/ftest.py

@@ -1607,8 +1607,9 @@ class TestFunctional(unittest.TestCase):
 
     def testExpandSizeBad(self):
         """Test an expanding entry which fails to provide contents"""
-        with self.assertRaises(ValueError) as e:
-            self._DoReadFileDtb('89_expand_size_bad.dts', map=True)
+        with test_util.capture_sys_output() as (stdout, stderr):
+            with self.assertRaises(ValueError) as e:
+                self._DoReadFileDtb('89_expand_size_bad.dts', map=True)
         self.assertIn("Node '/binman/_testing': Cannot obtain contents when "
                       'expanding entry', str(e.exception))
 
@@ -1724,6 +1725,25 @@ class TestFunctional(unittest.TestCase):
             TestFunctional._MakeInputFile('-boot', fd.read())
         data = self._DoReadFile('97_elf_strip.dts')
 
+    def testPackOverlapMap(self):
+        """Test that overlapping regions are detected"""
+        with test_util.capture_sys_output() as (stdout, stderr):
+            with self.assertRaises(ValueError) as e:
+                self._DoTestFile('14_pack_overlap.dts', map=True)
+        map_fname = tools.GetOutputFilename('image.map')
+        self.assertEqual("Wrote map file '%s' to show errors\n" % map_fname,
+                         stdout.getvalue())
+
+        # We should not get an inmage, but there should be a map file
+        self.assertFalse(os.path.exists(tools.GetOutputFilename('image.bin')))
+        self.assertTrue(os.path.exists(map_fname))
+        map_data = tools.ReadFile(map_fname)
+        self.assertEqual('''ImagePos    Offset      Size  Name
+<none>    00000000  00000007  main-section
+<none>     00000000  00000004  u-boot
+<none>     00000003  00000004  u-boot-align
+''', map_data)
+
 
 if __name__ == "__main__":
     unittest.main()