Revert "[lit] Remove dead code not referenced in the LLVM SVN repo."

Summary:
This reverts rL306623, which removed `FileBasedTest`, an abstract base class,
but did not also remove the usages of that class in the lit unit tests.
The revert fixes four test failures in the lit unit test suite.

Test plan:
As per the instructions in `utils/lit/README.txt`, run the lit unit
test suite:

```
utils/lit/lit.py \
    --path /path/to/your/llvm/build/bin \
    utils/lit/tests
```

Verify that the following tests fail before applying this patch, and
pass once the patch is applied:

```
lit :: test-data.py
lit :: test-output.py
lit :: xunit-output.py
```

In addition, run `check-llvm` to make sure the existing LLVM test suite
executes normally.

Reviewers: george.karpenkov, mgorny, dlj

Reviewed By: mgorny

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D35877

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309120 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 123 insertions, 74 deletions

diff --git a/utils/lit/lit/formats/__init__.py b/utils/lit/lit/formats/__init__.py
index 7d14ca4b535..3ff46e93ead 100644
--- a/utils/lit/lit/formats/__init__.py
+++ b/utils/lit/lit/formats/__init__.py
@@ -1,3 +1,8 @@
-from lit.formats.base import TestFormat  # noqa: F401
+from lit.formats.base import (  # noqa: F401
+    TestFormat,
+    FileBasedTest,
+    OneCommandPerFileTest
+)
+
 from lit.formats.googletest import GoogleTest  # noqa: F401
 from lit.formats.shtest import ShTest  # noqa: F401
diff --git a/utils/lit/lit/formats/base.py b/utils/lit/lit/formats/base.py
index baa9ff1d3b7..6721d17e334 100644
--- a/utils/lit/lit/formats/base.py
+++ b/utils/lit/lit/formats/base.py
@@ -1,50 +1,117 @@
-import abc
+from __future__ import absolute_import
+import os
+
+import lit.Test
+import lit.util
 
 class TestFormat(object):
-    """Base class for test formats.
-
-    A TestFormat encapsulates logic for finding and executing a certain type of
-    test. For example, a subclass FooTestFormat would contain the logic for
-    finding tests written in the 'Foo' format, and the logic for running a
-    single one.
-
-    TestFormat is an Abstract Base Class (ABC). It uses the Python abc.ABCMeta
-    type and associated @abc.abstractmethod decorator. Together, these provide
-    subclass behaviour which is notionally similar to C++ pure virtual classes:
-    only subclasses which implement all abstract methods can be instantiated
-    (the implementation may come from an intermediate base).
-
-    For details on ABCs, see: https://docs.python.org/2/library/abc.html. Note
-    that Python ABCs have extensive abilities beyond what is used here. For
-    TestFormat, we only care about enforcing that abstract methods are
-    implemented.
-    """
-
-    __metaclass__ = abc.ABCMeta
-
-    @abc.abstractmethod
-    def getTestsInDirectory(self, testSuite, path_in_suite, litConfig,
-                            localConfig):
-      """Finds tests of this format in the given directory.
-
-      Args:
-          testSuite: a Test.TestSuite object.
-          path_in_suite: the subpath under testSuite to look for tests.
-          litConfig: the LitConfig for the test suite.
-          localConfig: a LitConfig with local specializations.
-
-      Returns:
-          An iterable of Test.Test objects.
-      """
-
-    @abc.abstractmethod
+    pass
+
+###
+
+class FileBasedTest(TestFormat):
+    def getTestsInDirectory(self, testSuite, path_in_suite,
+                            litConfig, localConfig):
+        source_path = testSuite.getSourcePath(path_in_suite)
+        for filename in os.listdir(source_path):
+            # Ignore dot files and excluded tests.
+            if (filename.startswith('.') or
+                filename in localConfig.excludes):
+                continue
+
+            filepath = os.path.join(source_path, filename)
+            if not os.path.isdir(filepath):
+                base,ext = os.path.splitext(filename)
+                if ext in localConfig.suffixes:
+                    yield lit.Test.Test(testSuite, path_in_suite + (filename,),
+                                        localConfig)
+
+###
+
+import re
+import tempfile
+
+class OneCommandPerFileTest(TestFormat):
+    # FIXME: Refactor into generic test for running some command on a directory
+    # of inputs.
+
+    def __init__(self, command, dir, recursive=False,
+                 pattern=".*", useTempInput=False):
+        if isinstance(command, str):
+            self.command = [command]
+        else:
+            self.command = list(command)
+        if dir is not None:
+            dir = str(dir)
+        self.dir = dir
+        self.recursive = bool(recursive)
+        self.pattern = re.compile(pattern)
+        self.useTempInput = useTempInput
+
+    def getTestsInDirectory(self, testSuite, path_in_suite,
+                            litConfig, localConfig):
+        dir = self.dir
+        if dir is None:
+            dir = testSuite.getSourcePath(path_in_suite)
+
+        for dirname,subdirs,filenames in os.walk(dir):
+            if not self.recursive:
+                subdirs[:] = []
+
+            subdirs[:] = [d for d in subdirs
+                          if (d != '.svn' and
+                              d not in localConfig.excludes)]
+
+            for filename in filenames:
+                if (filename.startswith('.') or
+                    not self.pattern.match(filename) or
+                    filename in localConfig.excludes):
+                    continue
+
+                path = os.path.join(dirname,filename)
+                suffix = path[len(dir):]
+                if suffix.startswith(os.sep):
+                    suffix = suffix[1:]
+                test = lit.Test.Test(
+                    testSuite, path_in_suite + tuple(suffix.split(os.sep)),
+                    localConfig)
+                # FIXME: Hack?
+                test.source_path = path
+                yield test
+
+    def createTempInput(self, tmp, test):
+        raise NotImplementedError('This is an abstract method.')
+
     def execute(self, test, litConfig):
-      """Runs the given 'test', which is of this format.
+        if test.config.unsupported:
+            return (lit.Test.UNSUPPORTED, 'Test is unsupported')
+
+        cmd = list(self.command)
+
+        # If using temp input, create a temporary file and hand it to the
+        # subclass.
+        if self.useTempInput:
+            tmp = tempfile.NamedTemporaryFile(suffix='.cpp')
+            self.createTempInput(tmp, test)
+            tmp.flush()
+            cmd.append(tmp.name)
+        elif hasattr(test, 'source_path'):
+            cmd.append(test.source_path)
+        else:
+            cmd.append(test.getSourcePath())
+
+        out, err, exitCode = lit.util.executeCommand(cmd)
+
+        diags = out + err
+        if not exitCode and not diags.strip():
+            return lit.Test.PASS,''
 
-      Args:
-          test: a Test.Test object describing the test to run.
-          litConfig: the LitConfig for the test suite.
+        # Try to include some useful information.
+        report = """Command: %s\n""" % ' '.join(["'%s'" % a
+                                                 for a in cmd])
+        if self.useTempInput:
+            report += """Temporary File: %s\n""" % tmp.name
+            report += "--\n%s--\n""" % open(tmp.name).read()
+        report += """Output:\n--\n%s--""" % diags
 
-      Returns:
-          A tuple of (status:Test.ResultCode, message:str)
-      """
+        return lit.Test.FAIL, report
diff --git a/utils/lit/lit/formats/shtest.py b/utils/lit/lit/formats/shtest.py
index 01ecd192092..fdc9bd0241f 100644
--- a/utils/lit/lit/formats/shtest.py
+++ b/utils/lit/lit/formats/shtest.py
@@ -1,13 +1,12 @@
 from __future__ import absolute_import
 
-import os
-
-import lit.Test
 import lit.TestRunner
 import lit.util
-from .base import TestFormat
 
-class ShTest(TestFormat):
+from .base import FileBasedTest
+
+
+class ShTest(FileBasedTest):
     """ShTest is a format with one file per test.
 
     This is the primary format for regression tests as described in the LLVM
@@ -18,31 +17,9 @@ class ShTest(TestFormat):
     The ShTest files contain some number of shell-like command pipelines, along
     with assertions about what should be in the output.
     """
-
-    def __init__(self, execute_external = False):
-        """Initializer.
-
-        The 'execute_external' argument controls whether lit uses its internal
-        logic for command pipelines, or passes the command to a shell
-        subprocess.
-
-        Args:
-            execute_external: (optional) If true, use shell subprocesses instead
-                of lit's internal pipeline logic.
-        """
+    def __init__(self, execute_external=False):
         self.execute_external = execute_external
 
-    def getTestsInDirectory(self, testSuite, path_in_suite,
-                            litConfig, localConfig):
-        """Yields test files matching 'suffixes' from the localConfig."""
-        file_matches = lit.util.listdir_files(
-            testSuite.getSourcePath(path_in_suite),
-            localConfig.suffixes, localConfig.excludes)
-        for filename in file_matches:
-            yield lit.Test.Test(testSuite, path_in_suite + (filename,),
-                                localConfig)
-
     def execute(self, test, litConfig):
-        """Interprets and runs the given test file, and returns the result."""
         return lit.TestRunner.executeShTest(test, litConfig,
                                             self.execute_external)