@@ -41,6 +41,8 @@
 except ImportError:
     import simplejson as json
 
+from json import JSONDecodeError
+
 logging.basicConfig(format='%(levelname)s: %(message)s', level=logging.ERROR)
 log = logging.getLogger('global')
 
@@ -127,8 +129,10 @@ def load_specification(protocol, filepath, isSupplemental=False):
                 regex = re.compile(r"\/\*.*?\*\/", re.DOTALL)
                 parsed_json = json.loads(re.sub(regex, "", input_file.read()))
                 protocol.parse_specification(parsed_json, isSupplemental)
-        except ValueError as e:
-            raise Exception("Error parsing valid JSON in file: " + filepath + "\nParse error: " + str(e))
+        except JSONDecodeError as e:
+            # There's no way to get the filename from the outer exception handler, so insert it here.
+            setattr(e, 'input_filename', input_file.name)
+            raise
 
     protocol = models.Protocol(framework_name)
     for specification in supplemental_specification_filepaths:
@@ -304,6 +308,17 @@ def load_specification(protocol, filepath, isSupplemental=False):
 
     try:
         generate_from_specification(**options)
+    except JSONDecodeError as e:
+        message_lines = [
+            "Parse error trying to decode JSON!\n",
+            "error: {} at {}:{}:{}\n".format(e.msg, getattr(e, 'input_filename', '<unkwown>'), e.lineno, e.colno),
+            e.doc[:e.pos],
+            '~' * (e.colno - 1) + "^  // line {}, col {}: {}".format(e.lineno, e.colno, e.msg),
+        ]
+        log.error("\n".join(message_lines))
+        if not arg_options.test:
+            raise  # Force the build to fail after printing full message.
+
     except (ParseException, TypecheckException) as e:
         if arg_options.test:
             log.error(str(e))
 
@@ -0,0 +1,14 @@
+ERROR: Parse error trying to decode JSON!
+
+error: Expecting value at JavaScriptCore/inspector/scripts/tests/fail-on-invalid-json-with-context.json:9:1
+
+{
+    "domain": "Database",
+    "types": [
+        {
+            "id": "DatabaseId",
+            "type": "integer",
+            "description": "Unique identifier of Database object."
+        },
+
+^  // line 9, col 1: Expecting value
@@ -0,0 +1,9 @@
+{
+    "domain": "Database",
+    "types": [
+        {
+            "id": "DatabaseId",
+            "type": "integer",
+            "description": "Unique identifier of Database object."
+        },
+}
@@ -354,6 +354,10 @@
       os.path.join('Source', 'JavaScriptCore', 'jit', 'GDBInterface.cpp')],
      ["-readability/naming"]),
 
+    ([  # Some test cases intentionally use invalid JSON input files.
+        os.path.join('Source', 'JavaScriptCore', 'inspector', 'scripts', 'tests')],
+        ["-json/syntax"]),
+
     ([  # On some systems the trailing CR is causing parser failure.
       os.path.join('Source', 'JavaScriptCore', 'parser', 'Keywords.table')],
      ["+whitespace/carriage_return"]),