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Commit 8858d2a7 authored by Joe Onorato's avatar Joe Onorato
Browse files

Add a tool to let you enforce layering between packages in a java module. 

And build system support for it too.

Change-Id: I4dd5ed0b9edab6e8884b0d00cfeeae5fa38d967a
parent 0f23979f

core/clear_vars.mk

+1 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ LOCAL_INTERMEDIATE_SOURCES:= 
LOCAL_INTERMEDIATE_SOURCE_DIR:=

LOCAL_JAVACFLAGS:=

LOCAL_JAVA_LIBRARIES:=

LOCAL_JAVA_LAYERS_FILE:=

LOCAL_NO_STANDARD_LIBRARIES:=

LOCAL_CLASSPATH:=

LOCAL_DROIDDOC_USE_STANDARD_DOCLET:=

core/definitions.mk

+2 −0
Original line number Diff line number Diff line
@@ -1475,6 +1475,8 @@ $(hide) if [ -s $(PRIVATE_CLASS_INTERMEDIATES_DIR)/java-source-list-uniq ] ; the 
    \@$(PRIVATE_CLASS_INTERMEDIATES_DIR)/java-source-list-uniq \

    || ( rm -rf $(PRIVATE_CLASS_INTERMEDIATES_DIR) ; exit 41 ) \

fi

$(if $(PRIVATE_JAVA_LAYERS_FILE), $(hide) build/tools/java-layers.py \

    $(PRIVATE_JAVA_LAYERS_FILE) \@$(PRIVATE_CLASS_INTERMEDIATES_DIR)/java-source-list-uniq,)

$(hide) rm -f $(PRIVATE_CLASS_INTERMEDIATES_DIR)/java-source-list

$(hide) rm -f $(PRIVATE_CLASS_INTERMEDIATES_DIR)/java-source-list-uniq

$(if $(PRIVATE_JAR_EXCLUDE_FILES), $(hide) find $(PRIVATE_CLASS_INTERMEDIATES_DIR) \

core/java.mk

+8 −2
Original line number Diff line number Diff line
@@ -254,6 +254,11 @@ $(full_classes_stubs_jar) : $(LOCAL_BUILT_MODULE) | $(ACP) 
	$(hide) $(ACP) -fp $(PRIVATE_SOURCE_FILE) $@

ALL_MODULES.$(LOCAL_MODULE).STUBS := $(full_classes_stubs_jar)



# The layers file allows you to enforce a layering between java packages.

# Run build/tools/java-layers.py for more details.

layers_file := $(addprefix $(LOCAL_PATH)/, $(LOCAL_JAVA_LAYERS_FILE))

$(full_classes_compiled_jar): PRIVATE_JAVA_LAYERS_FILE := $(layers_file)



# Compile the java files to a .jar file.

# This intentionally depends on java_sources, not all_java_sources.

# Deps for generated source files must be handled separately,
@@ -261,8 +266,9 @@ ALL_MODULES.$(LOCAL_MODULE).STUBS := $(full_classes_stubs_jar) 
$(full_classes_compiled_jar): PRIVATE_JAVACFLAGS := $(LOCAL_JAVACFLAGS)

$(full_classes_compiled_jar): PRIVATE_JAR_EXCLUDE_FILES := $(LOCAL_JAR_EXCLUDE_FILES)

$(full_classes_compiled_jar): PRIVATE_DONT_DELETE_JAR_META_INF := $(LOCAL_DONT_DELETE_JAR_META_INF)

$(full_classes_compiled_jar): $(java_sources) $(java_resource_sources) $(full_java_lib_deps) $(jar_manifest_file) \

	$(RenderScript_file_stamp) $(proto_java_sources_file_stamp)

$(full_classes_compiled_jar): $(java_sources) $(java_resource_sources) $(full_java_lib_deps) \

        $(jar_manifest_file) $(layers_file) $(RenderScript_file_stamp) \

        $(proto_java_sources_file_stamp)

	$(transform-java-to-classes.jar)



# All of the rules after full_classes_compiled_jar are very unlikely

tools/java-layers.py

0 → 100755
+257 −0
Original line number Diff line number Diff line 
#!/usr/bin/env python



import os

import re

import sys



def fail_with_usage():

  sys.stderr.write("usage: java-layers.py DEPENDENCY_FILE SOURCE_DIRECTORIES...\n")

  sys.stderr.write("\n")

  sys.stderr.write("Enforces layering between java packages.  Scans\n")

  sys.stderr.write("DIRECTORY and prints errors when the packages violate\n")

  sys.stderr.write("the rules defined in the DEPENDENCY_FILE.\n")

  sys.stderr.write("\n")

  sys.stderr.write("Prints a warning when an unknown package is encountered\n")

  sys.stderr.write("on the assumption that it should fit somewhere into the\n")

  sys.stderr.write("layering.\n")

  sys.stderr.write("\n")

  sys.stderr.write("DEPENDENCY_FILE format\n")

  sys.stderr.write("  - # starts comment\n")

  sys.stderr.write("  - Lines consisting of two java package names:  The\n")

  sys.stderr.write("    first package listed must not contain any references\n")

  sys.stderr.write("    to any classes present in the second package, or any\n")

  sys.stderr.write("    of its dependencies.\n")

  sys.stderr.write("  - Lines consisting of one java package name:  The\n")

  sys.stderr.write("    packge is assumed to be a high level package and\n")

  sys.stderr.write("    nothing may depend on it.\n")

  sys.stderr.write("  - Lines consisting of a dash (+) followed by one java\n")

  sys.stderr.write("    package name: The package is considered a low level\n")

  sys.stderr.write("    package and may not import any of the other packages\n")

  sys.stderr.write("    listed in the dependency file.\n")

  sys.stderr.write("  - Lines consisting of a plus (-) followed by one java\n")

  sys.stderr.write("    package name: The package is considered \'legacy\'\n")

  sys.stderr.write("    and excluded from errors.\n")

  sys.stderr.write("\n")

  sys.exit(1)



class Dependency:

  def __init__(self, filename, lineno, lower, top, lowlevel, legacy):

    self.filename = filename

    self.lineno = lineno

    self.lower = lower

    self.top = top

    self.lowlevel = lowlevel

    self.legacy = legacy

    self.uppers = []

    self.transitive = set()



  def matches(self, imp):

    for d in self.transitive:

      if imp.startswith(d):

        return True

    return False



class Dependencies:

  def __init__(self, deps):

    def recurse(obj, dep, visited):

      global err

      if dep in visited:

        sys.stderr.write("%s:%d: Circular dependency found:\n"

            % (dep.filename, dep.lineno))

        for v in visited:

          sys.stderr.write("%s:%d:    Dependency: %s\n"

              % (v.filename, v.lineno, v.lower))

        err = True

        return

      visited.append(dep)

      for upper in dep.uppers:

        obj.transitive.add(upper)

        if upper in deps:

          recurse(obj, deps[upper], visited)

    self.deps = deps

    self.parts = [(dep.lower.split('.'),dep) for dep in deps.itervalues()]

    # transitive closure of dependencies

    for dep in deps.itervalues():

      recurse(dep, dep, [])

    # disallow everything from the low level components

    for dep in deps.itervalues():

      if dep.lowlevel:

        for d in deps.itervalues():

          if dep != d and not d.legacy:

            dep.transitive.add(d.lower)

    # disallow the 'top' components everywhere but in their own package

    for dep in deps.itervalues():

      if dep.top and not dep.legacy:

        for d in deps.itervalues():

          if dep != d and not d.legacy:

            d.transitive.add(dep.lower)

    for dep in deps.itervalues():

      dep.transitive = set([x+"." for x in dep.transitive])

    if False:

      for dep in deps.itervalues():

        print "-->", dep.lower, "-->", dep.transitive



  # Lookup the dep object for the given package.  If pkg is a subpackage

  # of one with a rule, that one will be returned.  If no matches are found,

  # None is returned.

  def lookup(self, pkg):

    # Returns the number of parts that match

    def compare_parts(parts, pkg):

      if len(parts) > len(pkg):

        return 0

      n = 0

      for i in range(0, len(parts)):

        if parts[i] != pkg[i]:

          return 0

        n = n + 1

      return n

    pkg = pkg.split(".")

    matched = 0

    result = None

    for (parts,dep) in self.parts:

      x = compare_parts(parts, pkg)

      if x > matched:

        matched = x

        result = dep

    return result



def parse_dependency_file(filename):

  global err

  f = file(filename)

  lines = f.readlines()

  f.close()

  def lineno(s, i):

    i[0] = i[0] + 1

    return (i[0],s)

  n = [0]

  lines = [lineno(x,n) for x in lines]

  lines = [(n,s.split("#")[0].strip()) for (n,s) in lines]

  lines = [(n,s) for (n,s) in lines if len(s) > 0]

  lines = [(n,s.split()) for (n,s) in lines]

  deps = {}

  for n,words in lines:

    if len(words) == 1:

      lower = words[0]

      top = True

      legacy = False

      lowlevel = False

      if lower[0] == '+':

        lower = lower[1:]

        top = False

        lowlevel = True

      elif lower[0] == '-':

        lower = lower[1:]

        legacy = True

      if lower in deps:

        sys.stderr.write(("%s:%d: Package '%s' already defined on"

            + " line %d.\n") % (filename, n, lower, deps[lower].lineno))

        err = True

      else:

        deps[lower] = Dependency(filename, n, lower, top, lowlevel, legacy)

    elif len(words) == 2:

      lower = words[0]

      upper = words[1]

      if lower in deps:

        dep = deps[lower]

        if dep.top:

          sys.stderr.write(("%s:%d: Can't add dependency to top level package "

            + "'%s'\n") % (filename, n, lower))

          err = True

      else:

        dep = Dependency(filename, n, lower, False, False, False)

        deps[lower] = dep

      dep.uppers.append(upper)

    else:

      sys.stderr.write("%s:%d: Too many words on line starting at \'%s\'\n" % (

          filename, n, words[2]))

      err = True

  return Dependencies(deps)



def find_java_files(srcs):

  result = []

  for d in srcs:

    if d[0] == '@':

      f = file(d[1:])

      result.extend([fn for fn in [s.strip() for s in f.readlines()]

          if len(fn) != 0])

      f.close()

    else:

      for root, dirs, files in os.walk(d):

        result.extend([os.sep.join((root,f)) for f in files

            if f.lower().endswith(".java")])

  return result



COMMENTS = re.compile("//.*?\n|/\*.*?\*/", re.S)

PACKAGE = re.compile("package\s+(.*)")

IMPORT = re.compile("import\s+(.*)")



def examine_java_file(deps, filename):

  global err

  # Yes, this is a crappy java parser.  Write a better one if you want to.

  f = file(filename)

  text = f.read()

  f.close()

  text = COMMENTS.sub("", text)

  index = text.find("{")

  if index < 0:

    sys.stderr.write(("%s: Error: Unable to parse java. Can't find class "

        + "declaration.\n") % filename)

    err = True

    return

  text = text[0:index]

  statements = [s.strip() for s in text.split(";")]

  # First comes the package declaration.  Then iterate while we see import

  # statements.  Anything else is either bad syntax that we don't care about

  # because the compiler will fail, or the beginning of the class declaration.

  m = PACKAGE.match(statements[0])

  if not m:

    sys.stderr.write(("%s: Error: Unable to parse java. Missing package "

        + "statement.\n") % filename)

    err = True

    return

  pkg = m.group(1)

  imports = []

  for statement in statements[1:]:

    m = IMPORT.match(statement)

    if not m:

      break

    imports.append(m.group(1))

  # Do the checking

  if False:

    print filename

    print "'%s' --> %s" % (pkg, imports)

  dep = deps.lookup(pkg)

  if not dep:

    sys.stderr.write(("%s: Error: Package does not appear in dependency file: "

      + "%s\n") % (filename, pkg))

    err = True

    return

  for imp in imports:

    if dep.matches(imp):

      sys.stderr.write("%s: Illegal import in package '%s' of '%s'\n"

          % (filename, pkg, imp))

      err = True



err = False



def main(argv):

  if len(argv) < 3:

    fail_with_usage()

  deps = parse_dependency_file(argv[1])



  if err:

    sys.exit(1)



  java = find_java_files(argv[2:])

  for filename in java:

    examine_java_file(deps, filename)



  if err:

    sys.stderr.write("%s: Using this file as dependency file.\n" % argv[1])

    sys.exit(1)



  sys.exit(0)



if __name__ == "__main__":

  main(sys.argv)