[iwyu_tool] Add --basedir argument

Enable specifiying a base dir relative to which the IWYU output should
be interpreted.

With the path normalization that happens when interpreting IWYU output,
we now need to normalize command-line arguments as well, in order for
filtering to work correctly.

Let test framework simulate a cwd to be able to test this.

2 files changed, 115 insertions, 11 deletions

diff --git a/fix_includes.py b/fix_includes.py
index fc223e8..a647782 100755
--- a/fix_includes.py
+++ b/fix_includes.py
@@ -320,7 +320,7 @@ class IWYUOutputParser(object):
     self.filename = '<unknown file>'
     self.lines_by_section = {}     # key is an RE, value is a list of lines
 
-  def _ProcessOneLine(self, line):
+  def _ProcessOneLine(self, line, basedir=None):
     """Reads one line of input, updates self, and returns False at EORecord.
 
     If the line matches one of the hard-coded section names, updates
@@ -347,7 +347,8 @@ class IWYUOutputParser(object):
       if m:
         # Check or set the filename (if the re has a group, it's for filename).
         if section_re.groups >= 1:
-          this_filename = m.group(1)
+          this_filename = NormalizeFilePath(basedir, m.group(1))
+
           if (self.current_section is not None and
               this_filename != self.filename):
             raise FixIncludesError('"%s" section for %s comes after "%s" for %s'
@@ -398,7 +399,8 @@ class IWYUOutputParser(object):
        FixIncludesError: for malformed-looking lines in the iwyu output.
     """
     for line in iwyu_output:
-      if not self._ProcessOneLine(line):   # returns False at end-of-record
+      if not self._ProcessOneLine(line, flags.basedir):
+        # returns False at end-of-record
         break
     else:                                  # for/else
       return None                          # at EOF
@@ -2202,7 +2204,7 @@ def FixManyFiles(iwyu_records, flags):
   return files_fixed
 
 
-def ProcessIWYUOutput(f, files_to_process, flags):
+def ProcessIWYUOutput(f, files_to_process, flags, cwd):
   """Fix the #include and forward-declare lines as directed by f.
 
   Given a file object that has the output of the include_what_you_use
@@ -2215,12 +2217,17 @@ def ProcessIWYUOutput(f, files_to_process, flags):
     flags: commandline flags, as parsed by optparse.  The only flag
        we use directly is flags.ignore_re, to indicate files not to
        process; we also pass the flags to other routines.
+    cwd: the current working directory, externalized for testing.
 
   Returns:
     The number of files that had to be modified (because they weren't
     already all correct).  In dry_run mode, returns the number of
     files that would have been modified.
   """
+  if files_to_process is not None:
+    files_to_process = [NormalizeFilePath(cwd, fname)
+                        for fname in files_to_process]
+
   # First collect all the iwyu data from stdin.
 
   # Maintain sort order by using OrderedDict instead of dict
@@ -2234,7 +2241,7 @@ def ProcessIWYUOutput(f, files_to_process, flags):
     except FixIncludesError as why:
       print('ERROR: %s' % why)
       continue
-    filename = iwyu_record.filename
+    filename = NormalizeFilePath(flags.basedir, iwyu_record.filename)
     if files_to_process is not None and filename not in files_to_process:
       print('(skipping %s: not listed on commandline)' % filename)
       continue
@@ -2267,6 +2274,11 @@ def ProcessIWYUOutput(f, files_to_process, flags):
   return FixManyFiles(contentful_records, flags)
 
 
+def NormalizeFilePath(basedir, filename):
+    if basedir and not os.path.isabs(filename):
+        return os.path.normpath(os.path.join(basedir, filename))
+    return filename
+
 def SortIncludesInFiles(files_to_process, flags):
   """For each file in files_to_process, sort its #includes.
 
@@ -2285,6 +2297,7 @@ def SortIncludesInFiles(files_to_process, flags):
   """
   sort_only_iwyu_records = []
   for filename in files_to_process:
+    filename = NormalizeFilePath(flags.basedir, filename)
     # An empty iwyu record has no adds or deletes, so its only effect
     # is to cause us to sort the #include lines.  (Since fix_includes
     # gets all its knowledge of where forward-declare lines are from
@@ -2358,6 +2371,11 @@ def main(argv):
   parser.add_option('--nokeep_iwyu_namespace_format', action='store_false',
                     dest='keep_iwyu_namespace_format')
 
+  parser.add_option('--basedir', '-p', default=None,
+                    help=('Specify the base directory. fix_includes will '
+                          'interpret non-absolute filenames relative to this '
+                          'path.'))
+
   (flags, files_to_modify) = parser.parse_args(argv[1:])
   if files_to_modify:
     files_to_modify = set(files_to_modify)
@@ -2375,7 +2393,7 @@ def main(argv):
       sys.exit('FATAL ERROR: -s flag requires a list of filenames')
     return SortIncludesInFiles(files_to_modify, flags)
   else:
-    return ProcessIWYUOutput(sys.stdin, files_to_modify, flags)
+    return ProcessIWYUOutput(sys.stdin, files_to_modify, flags, cwd=os.getcwd())
 
 
 if __name__ == '__main__':
diff --git a/fix_includes_test.py b/fix_includes_test.py
index 45a8d8d..a8c1236 100755
--- a/fix_includes_test.py
+++ b/fix_includes_test.py
@@ -41,6 +41,7 @@ class FakeFlags(object):
     self.separate_project_includes = None
     self.keep_iwyu_namespace_format = False
     self.reorder = True
+    self.basedir = None
 
 
 class FixIncludesBase(unittest.TestCase):
@@ -119,7 +120,7 @@ class FixIncludesBase(unittest.TestCase):
       self.expected_after_map[filename] = expected_after_contents
 
   def ProcessAndTest(self, iwyu_output, cmdline_files=None, unedited_files=[],
-                     expected_num_modified_files=None):
+                     expected_num_modified_files=None, cwd=None):
     """For all files mentioned in iwyu_output, compare expected and actual.
 
     Arguments:
@@ -132,6 +133,8 @@ class FixIncludesBase(unittest.TestCase):
           but fix_files has chosen not to edit for some reason.
        expected_num_modified_files: what we expect ProcessIWYUOutput to
           return.  If None, suppress this check.
+       cwd: working directory passed to ProcessIWYUOutput, used to normalize
+          paths in cmdline_files. If None, no normalization occurs.
     """
     filenames = re.findall('^(\S+) should add these lines:', iwyu_output, re.M)
     if not filenames:    # This is the other possible starting-line
@@ -140,13 +143,15 @@ class FixIncludesBase(unittest.TestCase):
 
     expected_after = []
     for filename in fix_includes.OrderedSet(filenames):  # uniquify
+      filename = fix_includes.NormalizeFilePath(self.flags.basedir, filename)
       if filename not in unedited_files:
         expected_after.extend(self.expected_after_map[filename])
 
     iwyu_output_as_file = StringIO(iwyu_output)
     num_modified_files = fix_includes.ProcessIWYUOutput(iwyu_output_as_file,
                                                         cmdline_files,
-                                                        self.flags)
+                                                        self.flags,
+                                                        cwd=cwd)
 
     if expected_after != self.actual_after_contents:
       print("=== Expected:")
@@ -245,7 +250,7 @@ int main() { return 0; }
     # we can't use the normal ProcessAndTest.
     iwyu_output_as_file = StringIO(iwyu_output)
     num_modified_files = fix_includes.ProcessIWYUOutput(iwyu_output_as_file,
-                                                        None, self.flags)
+                                                        None, self.flags, None)
     self.assertListEqual([], self.actual_after_contents)  # 'no diffs'
     self.assertEqual(0, num_modified_files)
 
@@ -269,7 +274,7 @@ int main() { return 0; }
     # we can't use the normal ProcessAndTest.
     iwyu_output_as_file = StringIO(iwyu_output)
     num_modified_files = fix_includes.ProcessIWYUOutput(iwyu_output_as_file,
-                                                        None, self.flags)
+                                                        None, self.flags, None)
     self.assertListEqual([], self.actual_after_contents)  # 'no diffs'
     self.assertEqual(0, num_modified_files)
 
@@ -3831,7 +3836,7 @@ The full include-list for dry_run:
 """
     self.RegisterFileContents({'dry_run': infile})
     num_modified_files = fix_includes.ProcessIWYUOutput(
-        StringIO(iwyu_output), ['dry_run'], self.flags)
+        StringIO(iwyu_output), ['dry_run'], self.flags, None)
     self.assertListEqual([], self.actual_after_contents)
     self.assertEqual(1, num_modified_files)
 
@@ -3976,6 +3981,87 @@ namespace ns { namespace ns4 { class Baz; } }
     self.RegisterFileContents({'add_fwd_declare_keep_iwyu_namespace': infile})
     self.ProcessAndTest(iwyu_output, expected_num_modified_files=1)
 
+  def testBasedir(self):
+    self.flags.basedir = "/project/build/"
+    iwyu_output = """\
+../src/source.cc should add these lines:
+
+../src/source.cc should remove these lines:
+- #include <unused.h> // lines 1-1
+
+The full include-list for ../src/source.cc:
+#include <used.h>
+---
+"""
+    infile = """\
+#include <unused.h> ///-
+#include <used.h>
+
+int main() { return 0; }
+"""
+    self.RegisterFileContents({'/project/src/source.cc': infile})
+    self.ProcessAndTest(iwyu_output, expected_num_modified_files=1)
+
+  def testBasedirWithFilesToProcess(self):
+    self.flags.basedir = "/project/build/"
+    iwyu_output = """\
+../src/changed.cc should add these lines:
+
+../src/changed.cc should remove these lines:
+- #include <unused.h> // lines 1-1
+
+The full include-list for ../src/changed.cc:
+#include <used.h>
+---
+"""
+    changed_file = """\
+#include <unused.h> ///-
+#include <used.h>
+
+int main() { return 0; }
+"""
+    unchanged_file = """\
+#include <unused.h>
+#include <used.h>
+
+int main() { return 0; }
+"""
+
+    iwyu_output += iwyu_output.replace('changed.cc', 'unchanged.cc')
+
+    self.RegisterFileContents({
+        '/project/src/changed.cc': changed_file,
+        '/project/src/unchanged.cc': unchanged_file
+        })
+    self.ProcessAndTest(iwyu_output, cmdline_files=['/project/src/changed.cc'],
+                        unedited_files=['/project/src/unchanged.cc'])
+
+  def testBasedirWithRelativeCmdlineFiles(self):
+    self.flags.basedir = "/project/build/"
+    iwyu_output = """\
+../src/changed.cc should add these lines:
+
+../src/changed.cc should remove these lines:
+- #include <unused.h> // lines 1-1
+
+The full include-list for ../src/changed.cc:
+#include <used.h>
+---
+"""
+    changed_file = """\
+#include <unused.h> ///-
+#include <used.h>
+
+int main() { return 0; }
+"""
+
+    self.RegisterFileContents({
+        # File path is normalized to absolute by ProcessIWYUOutput.
+        '/project/src/changed.cc': changed_file,
+        })
+    self.ProcessAndTest(iwyu_output, cmdline_files=['changed.cc'],
+                        cwd='/project/src')
+
   def testMain(self):
     """Make sure calling main doesn't crash.  Inspired by a syntax-error bug."""
     # Give an empty stdin so we don't actually try to parse anything.