[lldb/Lit] Change the lldbtest format to behave more like shell test.

[JDevlieghere]

Summary

The current lldbtest format has a number of shortcomings, all related to how we omit information based on why the test fails. For example, a successful test would print nothing, even when -a is passed to lit. It's not up to the test format to decide whether to print something or not, that's handled by lit itself. For other test results we would sometimes print stdout and stderr, but sometimes we would forget, such as when a timeout was reached or we couldn't parse the dotest output.

This patch changes the lldbtest format and makes it behave more like lit. We now always print the dotest invocation, the exit code, the output to stdout & stderr. If you're used to dealing with ShTests in lit, this will feel all very familiar.

[vsk]

Nice!

[mgorny]

I suppose you need to make the timeout branch entirely separate from the non-timeout branch, as the variable assignment does not take place then.

lldb/test/API/lldbtest.py

100

This crashes on timeout since exitCode is not declared:

UNRESOLVED: lldb-api :: tools/lldb-vscode/variables/TestVSCode_variables.py (1906 of 1907)
******************** TEST 'lldb-api :: tools/lldb-vscode/variables/TestVSCode_variables.py' FAILED ********************
Exception during script execution:
Traceback (most recent call last):
  File "/home/mgorny/llvm-project/llvm/utils/lit/lit/worker.py", line 91, in _execute_test_handle_errors
    return _adapt_result(test.config.test_format.execute(test, lit_config))
  File "/home/mgorny/llvm-project/llvm/tools/lldb/test/API/lldbtest.py", line 100, in execute
    ' '.join(cmd), exitCode)
UnboundLocalError: local variable 'exitCode' referenced before assignment

105

I suppose this will crash as well, and below.

lldb/test/API/lldbtest.py

def execute(self, test, litConfig):
                 python = subprocess.check_output([
                     sys.executable,
                     '-c',
                     'import sys; print(sys.executable)'
                 ]).decode('utf-8').strip()
                 shutil.copy(python, copied_python)
             cmd[0] = copied_python
 
+        timeoutInfo = None
         try:
             out, err, exitCode = lit.util.executeCommand(
                 cmd,
                 env=test.config.environment,
                 timeout=litConfig.maxIndividualTestTime)
         except lit.util.ExecuteCommandTimeoutException:
-            return (lit.Test.TIMEOUT, 'Reached timeout of {} seconds'.format(
-                litConfig.maxIndividualTestTime))
+            timeoutInfo = 'Reached timeout of {} seconds'.format(
+                litConfig.maxIndividualTestTime)
+
+        output = """Script:\n--\n%s\n--\nExit Code: %d\n""" % (
+            ' '.join(cmd), exitCode)
+        if timeoutInfo is not None:
+            output += """Timeout: %s\n""" % (timeoutInfo,)
+        output += "\n"
+
+        if out:
+            output += """Command Output (stdout):\n--\n%s\n--\n""" % (out,)
+        if err:
+            output += """Command Output (stderr):\n--\n%s\n--\n""" % (err,)
+
+        if timeoutInfo:
+            return lit.Test.TIMEOUT, output
 
         if exitCode:
             # Match FAIL but not XFAIL.
             for line in out.splitlines() + err.splitlines():
                 if line.startswith('FAIL:'):
-                    return lit.Test.FAIL, out + err
+                    return lit.Test.FAIL, output
 
             if 'XPASS:' in out or 'XPASS:' in err:
-                return lit.Test.XPASS, out + err
+                return lit.Test.XPASS, output
 
         has_unsupported_tests = 'UNSUPPORTED:' in out or 'UNSUPPORTED:' in err
         has_passing_tests = 'PASS:' in out or 'PASS:' in err
         if has_unsupported_tests and not has_passing_tests:
-            return lit.Test.UNSUPPORTED, out + err
+            return lit.Test.UNSUPPORTED, output
 
         passing_test_line = 'RESULT: PASSED'
         if passing_test_line not in out and passing_test_line not in err:
-            msg = ('Unable to find %r in dotest output (exit code %d):\n\n%s%s'
-                   % (passing_test_line, exitCode, out, err))
-            return lit.Test.UNRESOLVED, msg
+            return lit.Test.UNRESOLVED, output
 
-        return lit.Test.PASS, ''
+        return lit.Test.PASS, output