test/lit.cfg: add a new substitution '%FileCheck'

'%FileCheck' removes absolute paths of the source and build directory
from the input.  Overwhelming majority of tests don't intend to match
these paths.

Also add a substitution '%raw-FileCheck' that does not sanitize the
input.

Author: gribozavr

docs/Testing.rst

@@ -358,10 +358,16 @@ Other substitutions:
 * ``%{python}``: run the same Python interpreter that's being used to run the
   current ``lit`` test.
 
+* ``%FileCheck``: like the LLVM ``FileCheck`` utility, but occurrences of full
+  paths to the source and build directories in the input text are replaced with
+  path-independent constants.
+
+* ``%raw-FileCheck``: the LLVM ``FileCheck`` utility.
+
 When writing a test where output (or IR, SIL) depends on the bitness of the
 target CPU, use this pattern::
 
-  // RUN: %target-swift-frontend ... | FileCheck --check-prefix=CHECK --check-prefix=CHECK-%target-ptrsize %s
+  // RUN: %target-swift-frontend ... | %FileCheck --check-prefix=CHECK --check-prefix=CHECK-%target-ptrsize %s
 
   // CHECK: common line
   // CHECK-32: only for 32-bit
@@ -377,7 +383,7 @@ target CPU, use this pattern::
 When writing a test where output (or IR, SIL) depends on the target CPU itself,
 use this pattern::
 
-  // RUN: %target-swift-frontend ... | FileCheck --check-prefix=CHECK --check-prefix=CHECK-%target-cpu %s
+  // RUN: %target-swift-frontend ... | %FileCheck --check-prefix=CHECK --check-prefix=CHECK-%target-cpu %s
 
   // CHECK: common line
   // CHECK-i386:        only for i386

test/lit.cfg

@@ -26,6 +26,7 @@ import sys
 import tempfile
 import socket
 import glob
+import pipes
 
 import lit
 import lit.formats
@@ -288,6 +289,7 @@ config.swift_utils = os.path.join(config.swift_src_root, 'utils')
 config.line_directive = os.path.join(config.swift_utils, 'line-directive')
 config.gyb = os.path.join(config.swift_utils, 'gyb')
 config.rth = os.path.join(config.swift_utils, 'rth') # Resilience test helper
+config.PathSanitizingFileCheck = os.path.join(config.swift_utils, 'PathSanitizingFileCheck')
 config.swift_lib_dir = os.path.join(os.path.dirname(os.path.dirname(config.swift)), 'lib')
 
 # Find the resource directory.  Assume it's near the swift compiler if not set.
@@ -411,6 +413,7 @@ disallow('sil-extract')
 disallow('lldb-moduleimport-test')
 disallow('swift-ide-test')
 disallow('clang')
+disallow('FileCheck')
 
 config.substitutions.insert(0,
     ('%p',
@@ -983,6 +986,14 @@ config.substitutions.append(('%target-resilience-test', config.target_resilience
 config.substitutions.append(('%llvm-profdata', config.llvm_profdata))
 config.substitutions.append(('%llvm-cov', config.llvm_cov))
 
+config.substitutions.append(
+    ('%FileCheck',
+     '%s --sanitize \'BUILD_DIR=%s\' --sanitize \'SOURCE_DIR=%s\'' %
+      (config.PathSanitizingFileCheck,
+       pipes.quote(swift_obj_root),
+       pipes.quote(config.swift_src_root))))
+config.substitutions.append(('%raw-FileCheck', 'FileCheck'))
+
 # If static stdlib is present, enable static stdlib tests
 static_stdlib_path = os.path.join(os.path.join(config.swift_lib_dir,"swift_static"), config.target_sdk_name)
 libswiftCore_path = os.path.join(static_stdlib_path,"libswiftCore.a")

utils/PathSanitizingFileCheck

@@ -0,0 +1,54 @@
+#!/usr/bin/env python
+# utils/PathSanitizingFileCheck -*- python -*-
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See http://swift.org/LICENSE.txt for license information
+# See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+
+from __future__ import print_function
+
+import argparse
+import subprocess
+import sys
+
+def main():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        description="""
+PathSanitizingFileCheck is a wrapper around LLVM's FileCheck.  In addition
+to all FileCheck features, PathSanitizingFileCheck can replace given
+strings in the input with other strings.  This feature is used to replace
+paths to the source and build directories with path-independent
+constants.""")
+
+    parser.add_argument(
+        "--sanitize",
+        help="replace the given string with another string",
+        metavar="REPLACEMENT=SOURCE",
+        action="append",
+        dest="sanitize_strings",
+        default=[])
+
+    args, unknown_args = parser.parse_known_args()
+
+    stdin = sys.stdin.read()
+    for s in args.sanitize_strings:
+        replacement, pattern = s.split('=', 1)
+        stdin = stdin.replace(pattern, replacement)
+
+    p = subprocess.Popen(["FileCheck"] + unknown_args, stdin=subprocess.PIPE)
+    stdout, stderr = p.communicate(stdin)
+    if stdout is not None:
+        print(stdout)
+    if stderr is not None:
+        print(stderr, file=sys.stderr)
+    return p.wait()
+
+
+if __name__ == '__main__':
+    exit(main())
+