1 files changed, 251 insertions, 0 deletions
diff --git a/scripts/maint/add_c_file.py b/scripts/maint/add_c_file.py
new file mode 100755
index 0000000000..adf7ce79bb
--- /dev/null
+++ b/scripts/maint/add_c_file.py
@@ -0,0 +1,251 @@
+#!/usr/bin/env python3
+
+"""
+   Add a C file with matching header to the Tor codebase.  Creates
+   both files from templates, and adds them to the right include.am file.
+
+   Example usage:
+
+   % add_c_file.py ./src/feature/dirauth/ocelot.c
+"""
+
+import os
+import re
+import time
+
+def topdir_file(name):
+    """Strip opening "src" from a filename"""
+    if name.startswith("src/"):
+        name = name[4:]
+    return name
+
+def guard_macro(name):
+    """Return the guard macro that should be used for the header file 'name'.
+    """
+    td = topdir_file(name).replace(".", "_").replace("/", "_").upper()
+    return "TOR_{}".format(td)
+
+def makeext(name, new_extension):
+    """Replace the extension for the file called 'name' with 'new_extension'.
+    """
+    base = os.path.splitext(name)[0]
+    return base + "." + new_extension
+
+def instantiate_template(template, output_fname):
+    """
+    Fill in a template with string using the fields that should be used
+    for 'output_fname'.
+    """
+    names = {
+        # The relative location of the header file.
+        'header_path' : makeext(topdir_file(output_fname), "h"),
+        # The relative location of the C file file.
+        'c_file_path' : makeext(topdir_file(output_fname), "c"),
+        # The truncated name of the file.
+        'short_name' : os.path.basename(output_fname),
+        # The current year, for the copyright notice
+        'this_year' : time.localtime().tm_year,
+        # An appropriate guard macro, for the header.
+        'guard_macro' : guard_macro(output_fname),
+    }
+
+    return template.format(**names)
+
+HEADER_TEMPLATE = """\
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-{this_year}, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * @file {short_name}
+ * @brief Header for {c_file_path}
+ **/
+
+#ifndef {guard_macro}
+#define {guard_macro}
+
+#endif /* !defined({guard_macro}) */
+"""
+
+C_FILE_TEMPLATE = """\
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-{this_year}, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * @file {short_name}
+ * @brief DOCDOC
+ **/
+
+#include "orconfig.h"
+#include "{header_path}"
+"""
+
+class AutomakeChunk:
+    """
+    Represents part of an automake file.  If it is decorated with
+    an ADD_C_FILE comment, it has a "kind" based on what to add to it.
+    Otherwise, it only has a bunch of lines in it.
+    """
+    pat = re.compile(r'# ADD_C_FILE: INSERT (\S*) HERE', re.I)
+
+    def __init__(self):
+        self.lines = []
+        self.kind = ""
+
+    def addLine(self, line):
+        """
+        Insert a line into this chunk while parsing the automake file.
+        """
+        m = self.pat.match(line)
+        if m:
+            if self.lines:
+                raise ValueError("control line not preceded by a blank line")
+            self.kind = m.group(1)
+
+        self.lines.append(line)
+        if line.strip() == "":
+            return True
+
+        return False
+
+    def insertMember(self, member):
+        """
+        Add a new member to this chunk.  Try to insert it in alphabetical
+        order with matching indentation, but don't freak out too much if the
+        source isn't consistent.
+
+        Assumes that this chunk is of the form:
+           FOOBAR = \
+              X     \
+              Y     \
+              Z
+        """
+        prespace = "\t"
+        postspace = "\t\t"
+        for lineno, line in enumerate(self.lines):
+            m = re.match(r'(\s+)(\S+)(\s+)\\', line)
+            if not m:
+                continue
+            prespace, fname, postspace = m.groups()
+            if fname > member:
+                self.insert_before(lineno, member, prespace, postspace)
+                return
+        self.insert_at_end(member, prespace, postspace)
+
+    def insert_before(self, lineno, member, prespace, postspace):
+        self.lines.insert(lineno,
+                          "{}{}{}\\\n".format(prespace, member, postspace))
+
+    def insert_at_end(self, member, prespace, postspace):
+        lastline = self.lines[-1]
+        self.lines[-1] += '{}\\\n'.format(postspace)
+        self.lines.append("{}{}\n".format(prespace, member))
+
+    def dump(self, f):
+        """Write all the lines in this chunk to the file 'f'."""
+        for line in self.lines:
+            f.write(line)
+            if not line.endswith("\n"):
+                f.write("\n")
+
+class ParsedAutomake:
+    """A sort-of-parsed automake file, with identified chunks into which
+       headers and c files can be inserted.
+    """
+    def __init__(self):
+        self.chunks = []
+        self.by_type = {}
+
+    def addChunk(self, chunk):
+        """Add a newly parsed AutomakeChunk to this file."""
+        self.chunks.append(chunk)
+        self.by_type[chunk.kind.lower()] = chunk
+
+    def add_file(self, fname, kind):
+        """Insert a file of kind 'kind' to the appropriate section of this
+           file. Return True if we added it.
+        """
+        if kind.lower() in self.by_type:
+            self.by_type[kind.lower()].insertMember(fname)
+            return True
+        else:
+            return False
+
+    def dump(self, f):
+        """Write this file into a file 'f'."""
+        for chunk in self.chunks:
+            chunk.dump(f)
+
+def get_include_am_location(fname):
+    """Find the right include.am file for introducing a new file.  Return None
+       if we can't guess one.
+
+       Note that this function is imperfect because our include.am layout is
+       not (yet) consistent.
+    """
+    td = topdir_file(fname)
+    m = re.match(r'^lib/([a-z0-9_]*)/', td)
+    if m:
+        return "src/lib/{}/include.am".format(m.group(1))
+
+    if re.match(r'^(core|feature|app)/', td):
+        return "src/core/include.am"
+
+    if re.match(r'^test/', td):
+        return "src/test/include.am"
+
+    return None
+
+def run(fn):
+    """
+    Create a new C file and H file corresponding to the filename "fn", and
+    add them to include.am.
+    """
+
+    cf = makeext(fn, "c")
+    hf = makeext(fn, "h")
+
+    if os.path.exists(cf):
+        print("{} already exists".format(cf))
+        return 1
+    if os.path.exists(hf):
+        print("{} already exists".format(hf))
+        return 1
+
+    with open(cf, 'w') as f:
+        f.write(instantiate_template(C_FILE_TEMPLATE, cf))
+
+    with open(hf, 'w') as f:
+        f.write(instantiate_template(HEADER_TEMPLATE, hf))
+
+    iam = get_include_am_location(cf)
+    if iam is None or not os.path.exists(iam):
+        print("Made files successfully but couldn't identify include.am for {}"
+              .format(cf))
+        return 1
+
+    amfile = ParsedAutomake()
+    cur_chunk = AutomakeChunk()
+    with open(iam) as f:
+        for line in f:
+            if cur_chunk.addLine(line):
+                amfile.addChunk(cur_chunk)
+                cur_chunk = AutomakeChunk()
+        amfile.addChunk(cur_chunk)
+
+    amfile.add_file(cf, "sources")
+    amfile.add_file(hf, "headers")
+
+    with open(iam+".tmp", 'w') as f:
+        amfile.dump(f)
+
+    os.rename(iam+".tmp", iam)
+
+if __name__ == '__main__':
+    import sys
+    sys.exit(run(sys.argv[1]))