diff --git a/.pylintrc b/.pylintrc
new file mode 100644
index 000000000..60bdfd4c0
--- /dev/null
+++ b/.pylintrc
@@ -0,0 +1,588 @@
+[MASTER]
+
+# A comma-separated list of package or module names from where C extensions may
+# be loaded. Extensions are loading into the active Python interpreter and may
+# run arbitrary code.
+extension-pkg-whitelist=
+
+# Add files or directories to the blacklist. They should be base names, not
+# paths.
+ignore=CVS
+
+# Add files or directories matching the regex patterns to the blacklist. The
+# regex matches against base names, not paths.
+ignore-patterns=
+
+# Python code to execute, usually for sys.path manipulation such as
+# pygtk.require().
+#init-hook=
+
+# Use multiple processes to speed up Pylint. Specifying 0 will auto-detect the
+# number of processors available to use.
+jobs=1
+
+# Control the amount of potential inferred values when inferring a single
+# object. This can help the performance when dealing with large functions or
+# complex, nested conditions.
+limit-inference-results=100
+
+# List of plugins (as comma separated values of python module names) to load,
+# usually to register additional checkers.
+load-plugins=
+
+# Pickle collected data for later comparisons.
+persistent=yes
+
+# Specify a configuration file.
+#rcfile=
+
+# When enabled, pylint would attempt to guess common misconfiguration and emit
+# user-friendly hints instead of false-positive error messages.
+suggestion-mode=yes
+
+# Allow loading of arbitrary C extensions. Extensions are imported into the
+# active Python interpreter and may run arbitrary code.
+unsafe-load-any-extension=no
+
+
+[MESSAGES CONTROL]
+
+# Only show warnings with the listed confidence levels. Leave empty to show
+# all. Valid levels: HIGH, INFERENCE, INFERENCE_FAILURE, UNDEFINED.
+confidence=
+
+# Disable the message, report, category or checker with the given id(s). You
+# can either give multiple identifiers separated by comma (,) or put this
+# option multiple times (only on the command line, not in the configuration
+# file where it should appear only once). You can also use "--disable=all" to
+# disable everything first and then reenable specific checks. For example, if
+# you want to run only the similarities checker, you can use "--disable=all
+# --enable=similarities". If you want to run only the classes checker, but have
+# no Warning level messages displayed, use "--disable=all --enable=classes
+# --disable=W".
+disable=print-statement,
+        parameter-unpacking,
+        unpacking-in-except,
+        old-raise-syntax,
+        backtick,
+        long-suffix,
+        old-ne-operator,
+        old-octal-literal,
+        import-star-module-level,
+        non-ascii-bytes-literal,
+        raw-checker-failed,
+        bad-inline-option,
+        locally-disabled,
+        file-ignored,
+        suppressed-message,
+        useless-suppression,
+        deprecated-pragma,
+        use-symbolic-message-instead,
+        apply-builtin,
+        basestring-builtin,
+        buffer-builtin,
+        cmp-builtin,
+        coerce-builtin,
+        execfile-builtin,
+        file-builtin,
+        long-builtin,
+        raw_input-builtin,
+        reduce-builtin,
+        standarderror-builtin,
+        unicode-builtin,
+        xrange-builtin,
+        coerce-method,
+        delslice-method,
+        getslice-method,
+        setslice-method,
+        no-absolute-import,
+        old-division,
+        dict-iter-method,
+        dict-view-method,
+        next-method-called,
+        metaclass-assignment,
+        indexing-exception,
+        raising-string,
+        reload-builtin,
+        oct-method,
+        hex-method,
+        nonzero-method,
+        cmp-method,
+        input-builtin,
+        round-builtin,
+        intern-builtin,
+        unichr-builtin,
+        map-builtin-not-iterating,
+        zip-builtin-not-iterating,
+        range-builtin-not-iterating,
+        filter-builtin-not-iterating,
+        using-cmp-argument,
+        eq-without-hash,
+        div-method,
+        idiv-method,
+        rdiv-method,
+        exception-message-attribute,
+        invalid-str-codec,
+        sys-max-int,
+        bad-python3-import,
+        deprecated-string-function,
+        deprecated-str-translate-call,
+        deprecated-itertools-function,
+        deprecated-types-field,
+        next-method-defined,
+        dict-items-not-iterating,
+        dict-keys-not-iterating,
+        dict-values-not-iterating,
+        deprecated-operator-function,
+        deprecated-urllib-function,
+        xreadlines-attribute,
+        deprecated-sys-function,
+        exception-escape,
+        comprehension-escape,
+        fixme
+
+# Enable the message, report, category or checker with the given id(s). You can
+# either give multiple identifier separated by comma (,) or put this option
+# multiple time (only on the command line, not in the configuration file where
+# it should appear only once). See also the "--disable" option for examples.
+enable=c-extension-no-member
+
+
+[REPORTS]
+
+# Python expression which should return a score less than or equal to 10. You
+# have access to the variables 'error', 'warning', 'refactor', and 'convention'
+# which contain the number of messages in each category, as well as 'statement'
+# which is the total number of statements analyzed. This score is used by the
+# global evaluation report (RP0004).
+evaluation=10.0 - ((float(5 * error + warning + refactor + convention) / statement) * 10)
+
+# Template used to display messages. This is a python new-style format string
+# used to format the message information. See doc for all details.
+#msg-template=
+
+# Set the output format. Available formats are text, parseable, colorized, json
+# and msvs (visual studio). You can also give a reporter class, e.g.
+# mypackage.mymodule.MyReporterClass.
+output-format=text
+
+# Tells whether to display a full report or only the messages.
+reports=no
+
+# Activate the evaluation score.
+score=yes
+
+
+[REFACTORING]
+
+# Maximum number of nested blocks for function / method body
+max-nested-blocks=5
+
+# Complete name of functions that never returns. When checking for
+# inconsistent-return-statements if a never returning function is called then
+# it will be considered as an explicit return statement and no message will be
+# printed.
+never-returning-functions=sys.exit
+
+
+[BASIC]
+
+# Naming style matching correct argument names.
+argument-naming-style=snake_case
+
+# Regular expression matching correct argument names. Overrides argument-
+# naming-style.
+#argument-rgx=
+
+# Naming style matching correct attribute names.
+attr-naming-style=snake_case
+
+# Regular expression matching correct attribute names. Overrides attr-naming-
+# style.
+#attr-rgx=
+
+# Bad variable names which should always be refused, separated by a comma.
+bad-names=foo,
+          bar,
+          baz,
+          toto,
+          tutu,
+          tata
+
+# Naming style matching correct class attribute names.
+class-attribute-naming-style=any
+
+# Regular expression matching correct class attribute names. Overrides class-
+# attribute-naming-style.
+#class-attribute-rgx=
+
+# Naming style matching correct class names.
+class-naming-style=PascalCase
+
+# Regular expression matching correct class names. Overrides class-naming-
+# style.
+#class-rgx=
+
+# Naming style matching correct constant names.
+const-naming-style=UPPER_CASE
+
+# Regular expression matching correct constant names. Overrides const-naming-
+# style.
+#const-rgx=
+
+# Minimum line length for functions/classes that require docstrings, shorter
+# ones are exempt.
+docstring-min-length=-1
+
+# Naming style matching correct function names.
+function-naming-style=snake_case
+
+# Regular expression matching correct function names. Overrides function-
+# naming-style.
+#function-rgx=
+
+# Good variable names which should always be accepted, separated by a comma.
+good-names=i,
+           j,
+           k,
+           ex,
+           Run,
+           _
+
+# Include a hint for the correct naming format with invalid-name.
+include-naming-hint=no
+
+# Naming style matching correct inline iteration names.
+inlinevar-naming-style=any
+
+# Regular expression matching correct inline iteration names. Overrides
+# inlinevar-naming-style.
+#inlinevar-rgx=
+
+# Naming style matching correct method names.
+method-naming-style=snake_case
+
+# Regular expression matching correct method names. Overrides method-naming-
+# style.
+#method-rgx=
+
+# Naming style matching correct module names.
+module-naming-style=snake_case
+
+# Regular expression matching correct module names. Overrides module-naming-
+# style.
+#module-rgx=
+
+# Colon-delimited sets of names that determine each other's naming style when
+# the name regexes allow several styles.
+name-group=
+
+# Regular expression which should only match function or class names that do
+# not require a docstring.
+no-docstring-rgx=^_
+
+# List of decorators that produce properties, such as abc.abstractproperty. Add
+# to this list to register other decorators that produce valid properties.
+# These decorators are taken in consideration only for invalid-name.
+property-classes=abc.abstractproperty
+
+# Naming style matching correct variable names.
+variable-naming-style=snake_case
+
+# Regular expression matching correct variable names. Overrides variable-
+# naming-style.
+#variable-rgx=
+
+
+[SIMILARITIES]
+
+# Ignore comments when computing similarities.
+ignore-comments=yes
+
+# Ignore docstrings when computing similarities.
+ignore-docstrings=yes
+
+# Ignore imports when computing similarities.
+ignore-imports=no
+
+# Minimum lines number of a similarity.
+min-similarity-lines=4
+
+
+[FORMAT]
+
+# Expected format of line ending, e.g. empty (any line ending), LF or CRLF.
+expected-line-ending-format=
+
+# Regexp for a line that is allowed to be longer than the limit.
+ignore-long-lines=^\s*(# )?<?https?://\S+>?$
+
+# Number of spaces of indent required inside a hanging or continued line.
+indent-after-paren=4
+
+# String used as indentation unit. This is usually "    " (4 spaces) or "\t" (1
+# tab).
+indent-string='    '
+
+# Maximum number of characters on a single line.
+max-line-length=100
+
+# Maximum number of lines in a module.
+max-module-lines=1000
+
+# List of optional constructs for which whitespace checking is disabled. `dict-
+# separator` is used to allow tabulation in dicts, etc.: {1  : 1,\n222: 2}.
+# `trailing-comma` allows a space between comma and closing bracket: (a, ).
+# `empty-line` allows space-only lines.
+no-space-check=trailing-comma,
+               dict-separator
+
+# Allow the body of a class to be on the same line as the declaration if body
+# contains single statement.
+single-line-class-stmt=no
+
+# Allow the body of an if to be on the same line as the test if there is no
+# else.
+single-line-if-stmt=no
+
+
+[MISCELLANEOUS]
+
+# List of note tags to take in consideration, separated by a comma.
+notes=FIXME,
+      XXX,
+      TODO
+
+
+[TYPECHECK]
+
+# List of decorators that produce context managers, such as
+# contextlib.contextmanager. Add to this list to register other decorators that
+# produce valid context managers.
+contextmanager-decorators=contextlib.contextmanager
+
+# List of members which are set dynamically and missed by pylint inference
+# system, and so shouldn't trigger E1101 when accessed. Python regular
+# expressions are accepted.
+generated-members=
+
+# Tells whether missing members accessed in mixin class should be ignored. A
+# mixin class is detected if its name ends with "mixin" (case insensitive).
+ignore-mixin-members=yes
+
+# Tells whether to warn about missing members when the owner of the attribute
+# is inferred to be None.
+ignore-none=yes
+
+# This flag controls whether pylint should warn about no-member and similar
+# checks whenever an opaque object is returned when inferring. The inference
+# can return multiple potential results while evaluating a Python object, but
+# some branches might not be evaluated, which results in partial inference. In
+# that case, it might be useful to still emit no-member and other checks for
+# the rest of the inferred objects.
+ignore-on-opaque-inference=yes
+
+# List of class names for which member attributes should not be checked (useful
+# for classes with dynamically set attributes). This supports the use of
+# qualified names.
+ignored-classes=optparse.Values,thread._local,_thread._local
+
+# List of module names for which member attributes should not be checked
+# (useful for modules/projects where namespaces are manipulated during runtime
+# and thus existing member attributes cannot be deduced by static analysis). It
+# supports qualified module names, as well as Unix pattern matching.
+ignored-modules=
+
+# Show a hint with possible names when a member name was not found. The aspect
+# of finding the hint is based on edit distance.
+missing-member-hint=yes
+
+# The minimum edit distance a name should have in order to be considered a
+# similar match for a missing member name.
+missing-member-hint-distance=1
+
+# The total number of similar names that should be taken in consideration when
+# showing a hint for a missing member.
+missing-member-max-choices=1
+
+# List of decorators that change the signature of a decorated function.
+signature-mutators=
+
+
+[SPELLING]
+
+# Limits count of emitted suggestions for spelling mistakes.
+max-spelling-suggestions=4
+
+# Spelling dictionary name. Available dictionaries: none. To make it work,
+# install the python-enchant package.
+spelling-dict=
+
+# List of comma separated words that should not be checked.
+spelling-ignore-words=
+
+# A path to a file that contains the private dictionary; one word per line.
+spelling-private-dict-file=
+
+# Tells whether to store unknown words to the private dictionary (see the
+# --spelling-private-dict-file option) instead of raising a message.
+spelling-store-unknown-words=no
+
+
+[VARIABLES]
+
+# List of additional names supposed to be defined in builtins. Remember that
+# you should avoid defining new builtins when possible.
+additional-builtins=
+
+# Tells whether unused global variables should be treated as a violation.
+allow-global-unused-variables=yes
+
+# List of strings which can identify a callback function by name. A callback
+# name must start or end with one of those strings.
+callbacks=cb_,
+          _cb
+
+# A regular expression matching the name of dummy variables (i.e. expected to
+# not be used).
+dummy-variables-rgx=_+$|(_[a-zA-Z0-9_]*[a-zA-Z0-9]+?$)|dummy|^ignored_|^unused_
+
+# Argument names that match this expression will be ignored. Default to name
+# with leading underscore.
+ignored-argument-names=_.*|^ignored_|^unused_
+
+# Tells whether we should check for unused import in __init__ files.
+init-import=no
+
+# List of qualified module names which can have objects that can redefine
+# builtins.
+redefining-builtins-modules=six.moves,past.builtins,future.builtins,builtins,io
+
+
+[LOGGING]
+
+# Format style used to check logging format string. `old` means using %
+# formatting, `new` is for `{}` formatting,and `fstr` is for f-strings.
+logging-format-style=old
+
+# Logging modules to check that the string format arguments are in logging
+# function parameter format.
+logging-modules=logging
+
+
+[STRING]
+
+# This flag controls whether the implicit-str-concat-in-sequence should
+# generate a warning on implicit string concatenation in sequences defined over
+# several lines.
+check-str-concat-over-line-jumps=no
+
+
+[IMPORTS]
+
+# List of modules that can be imported at any level, not just the top level
+# one.
+allow-any-import-level=
+
+# Allow wildcard imports from modules that define __all__.
+allow-wildcard-with-all=no
+
+# Analyse import fallback blocks. This can be used to support both Python 2 and
+# 3 compatible code, which means that the block might have code that exists
+# only in one or another interpreter, leading to false positives when analysed.
+analyse-fallback-blocks=no
+
+# Deprecated modules which should not be used, separated by a comma.
+deprecated-modules=optparse,tkinter.tix
+
+# Create a graph of external dependencies in the given file (report RP0402 must
+# not be disabled).
+ext-import-graph=
+
+# Create a graph of every (i.e. internal and external) dependencies in the
+# given file (report RP0402 must not be disabled).
+import-graph=
+
+# Create a graph of internal dependencies in the given file (report RP0402 must
+# not be disabled).
+int-import-graph=
+
+# Force import order to recognize a module as part of the standard
+# compatibility libraries.
+known-standard-library=
+
+# Force import order to recognize a module as part of a third party library.
+known-third-party=enchant
+
+# Couples of modules and preferred modules, separated by a comma.
+preferred-modules=
+
+
+[CLASSES]
+
+# List of method names used to declare (i.e. assign) instance attributes.
+defining-attr-methods=__init__,
+                      __new__,
+                      setUp,
+                      __post_init__
+
+# List of member names, which should be excluded from the protected access
+# warning.
+exclude-protected=_asdict,
+                  _fields,
+                  _replace,
+                  _source,
+                  _make
+
+# List of valid names for the first argument in a class method.
+valid-classmethod-first-arg=cls
+
+# List of valid names for the first argument in a metaclass class method.
+valid-metaclass-classmethod-first-arg=cls
+
+
+[DESIGN]
+
+# Maximum number of arguments for function / method.
+max-args=5
+
+# Maximum number of attributes for a class (see R0902).
+max-attributes=7
+
+# Maximum number of boolean expressions in an if statement (see R0916).
+max-bool-expr=5
+
+# Maximum number of branch for function / method body.
+max-branches=12
+
+# Maximum number of locals for function / method body.
+max-locals=15
+
+# Maximum number of parents for a class (see R0901).
+max-parents=7
+
+# Maximum number of public methods for a class (see R0904).
+max-public-methods=20
+
+# Maximum number of return / yield for function / method body.
+max-returns=6
+
+# Maximum number of statements in function / method body.
+max-statements=50
+
+# Minimum number of public methods for a class (see R0903).
+min-public-methods=2
+
+
+[EXCEPTIONS]
+
+# Exceptions that will emit a warning when being caught. Defaults to
+# "BaseException, Exception".
+overgeneral-exceptions=BaseException,
+                       Exception
+
+# String used as indentation unit. We differ from PEP8's normal 4 spaces.
+indent-string='  '
+
+# Maximum number of characters on a single line.
+max-line-length=80
\ No newline at end of file
diff --git a/.style.yapf b/.style.yapf
new file mode 100644
index 000000000..f1eceb610
--- /dev/null
+++ b/.style.yapf
@@ -0,0 +1,5 @@
+[style]
+based_on_style = google
+column_limit = 80
+indent_width = 2
+split_before_named_assigns = true
diff --git a/.travis.yml b/.travis.yml
index 054090458..2064c60d3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,6 +12,10 @@ install:
 
 matrix:
   include:
+    - name: "presubmit"
+      install:
+        - pip install -r infra/dev-requirements.txt
+      script: ./infra/presubmit.py
     - name: "libfuzzer address x86_64"
       env:
         - TRAVIS_ENGINE=libfuzzer
diff --git a/infra/dev-requirements.txt b/infra/dev-requirements.txt
new file mode 100644
index 000000000..55e3b5049
--- /dev/null
+++ b/infra/dev-requirements.txt
@@ -0,0 +1,5 @@
+# Requirements for submitting code changes to infra/ (needed by presubmit.py).
+pylint==2.4.4
+yapf==0.28.0
+PyYAML==5.1
+
diff --git a/infra/presubmit.py b/infra/presubmit.py
new file mode 100755
index 000000000..7e05bdb4a
--- /dev/null
+++ b/infra/presubmit.py
@@ -0,0 +1,312 @@
+#!/usr/bin/env python3
+# Copyright 2020 Google LLC.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+################################################################################
+"""Check code for common issues before submitting."""
+
+import argparse
+import os
+import subprocess
+import sys
+import yaml
+
+_SRC_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+
+def _is_project_file(actual_path, expected_filename):
+  """Returns True if actual_path's name is |expected_filename| and is a file
+  that exists and is in in projects/."""
+  if os.path.basename(actual_path) != expected_filename:
+    return False
+
+  if os.path.basename(os.path.dirname(
+      os.path.dirname(actual_path))) != 'projects':
+    return False
+
+  return os.path.exists(actual_path)
+
+
+# TODO: Check for -fsanitize=fuzzer in files as well.
+
+
+def _check_one_lib_fuzzing_engine(build_sh_file):
+  """Returns False if |build_sh_file| contains -lFuzzingEngine.
+  This is deprecated behavior. $LIB_FUZZING_ENGINE should be used instead
+  so that -fsanitize=fuzzer is used."""
+  if not _is_project_file(build_sh_file, 'build.sh'):
+    return True
+
+  with open(build_sh_file) as build_sh:
+    build_sh_lines = build_sh.readlines()
+  for line_num, line in enumerate(build_sh_lines):
+    uncommented_code = line.split('#')[0]
+    if '-lFuzzingEngine' in uncommented_code:
+      print(
+          'Error: build.sh contains deprecated "-lFuzzingEngine" on line: {0}. '
+          'Please use "$LIB_FUZZING_ENGINE" instead.'.format(line_num))
+      return False
+  return True
+
+
+def check_lib_fuzzing_engine(paths):
+  """Call _check_one_lib_fuzzing_engine on each path in |paths|. Return True if
+  the result of every call is True."""
+  return all([_check_one_lib_fuzzing_engine(path) for path in paths])
+
+
+class ProjectYamlChecker:
+  """Checks for a project.yaml file."""
+
+  # Sections in a project.yaml and the constant values that they are allowed
+  # to have.
+  SECTIONS_AND_CONSTANTS = {
+      'sanitizers': {'address', 'none', 'memory', 'undefined', 'dataflow'},
+      'architectures': {'i386', 'x86_64'},
+      'engines': {'afl', 'libfuzzer', 'honggfuzz', 'dataflow'}
+  }
+
+  # Note: this list must be updated when we allow new sections.
+  VALID_SECTION_NAMES = [
+      'homepage', 'primary_contact', 'auto_ccs', 'sanitizers', 'architectures',
+      'disabled', 'view_restrictions', 'coverage_extra_args', 'vendor_ccs'
+  ]
+
+  # Note that some projects like boost only have auto-ccs. However, forgetting
+  # primary contact is probably a mistake.
+  REQUIRED_SECTIONS = ['primary_contact']
+
+  def __init__(self, filename):
+    self.filename = filename
+    with open(filename) as file_handle:
+      self.data = yaml.safe_load(file_handle)
+
+    self.success = True
+
+  def do_checks(self):
+    """Do all project.yaml checks. Return True if they pass."""
+    if self.is_disabled():
+      return True
+
+    checks = [
+        self.check_project_yaml_constants, self.check_required_sections,
+        self.check_valid_section_names, self.check_valid_emails
+    ]
+    for check_function in checks:
+      check_function()
+    return self.success
+
+  def is_disabled(self):
+    """Is this project disabled."""
+    return self.data.get('disabled', False)
+
+  def print_error(self, message, *args):
+    """Print an error message and set self.success to False."""
+    self.success = False
+    message = message % args
+    print('Error in %s: %s' % (self.filename, message))
+
+  def check_project_yaml_constants(self):
+    """Check that certain sections only have certain constant values."""
+    for section, allowed_constants in self.SECTIONS_AND_CONSTANTS.items():
+      if section not in self.data:
+        continue
+      actual_constants = self.data[section]
+      for constant in actual_constants:
+        if constant not in allowed_constants:
+          self.print_error('%s (in %s section) is not one of %s', constant,
+                           section, allowed_constants)
+
+  def check_valid_section_names(self):
+    """Check that only valid sections are included."""
+    for name in self.data:
+      if name not in self.VALID_SECTION_NAMES:
+        self.print_error('%s not a valid section name (%s)', name,
+                         self.VALID_SECTION_NAMES)
+
+  def check_required_sections(self):
+    """Check that all required sections are present."""
+    for section in self.REQUIRED_SECTIONS:
+      if section not in self.data:
+        self.print_error('No %s section.', section)
+
+  def check_valid_emails(self):
+    """Check that emails are valid looking."""
+    # Get email addresses.
+    email_addresses = []
+    for section in ['auto_ccs', 'primary_contact']:
+      email_addresses.extend(self.data.get(section, []))
+
+    # Sanity check them.
+    for email_address in email_addresses:
+      if '@' not in email_address or '.' not in email_address:
+        self.print_error('%s is an invalid email address.', email_address)
+
+
+def _check_one_project_yaml(project_yaml_filename):
+  """Do checks on the project.yaml file."""
+  if not _is_project_file(project_yaml_filename, 'project.yaml'):
+    return True
+
+  checker = ProjectYamlChecker(project_yaml_filename)
+  return checker.do_checks()
+
+
+def check_project_yaml(paths):
+  """Call _check_one_project_yaml on each path in |paths|. Return True if
+  the result of every call is True."""
+  return all([_check_one_project_yaml(path) for path in paths])
+
+
+def do_checks(changed_files):
+  """Run all presubmit checks return False if any fails."""
+  checks = [
+      check_license, yapf, lint, check_project_yaml, check_lib_fuzzing_engine
+  ]
+  # Use a list comprehension here and in other cases where we use all() so that
+  # we don't quit early on failure. This is more user-friendly since the more
+  # errors we spit out at once, the less frequently the less check-fix-check
+  # cycles they need to do.
+  return all([check(changed_files) for check in checks])
+
+
+_CHECK_LICENSE_FILENAMES = ['Dockerfile']
+_CHECK_LICENSE_EXTENSIONS = [
+    '.bash',
+    '.c',
+    '.cc',
+    '.cpp',
+    '.css',
+    '.h',
+    '.htm',
+    '.html',
+    '.js',
+    '.proto',
+    '.py',
+    '.sh',
+    '.yaml',
+]
+_LICENSE_STRING = 'http://www.apache.org/licenses/LICENSE-2.0'
+
+
+def check_license(paths):
+  """Validate license header."""
+  if not paths:
+    return True
+
+  success = True
+  for path in paths:
+    filename = os.path.basename(path)
+    extension = os.path.splitext(path)[1]
+    if (filename not in _CHECK_LICENSE_FILENAMES and
+        extension not in _CHECK_LICENSE_EXTENSIONS):
+      continue
+
+    with open(path) as file_handle:
+      if _LICENSE_STRING not in file_handle.read():
+        print('Missing license header in file %s.' % str(path))
+        success = False
+
+  return success
+
+
+def bool_to_returncode(success):
+  """Return 0 if |success|. Otherwise return 1."""
+  if success:
+    print('Success.')
+    return 0
+
+  print('Failed.')
+  return 1
+
+
+def is_python(path):
+  """Returns True if |path| ends in .py."""
+  return os.path.splitext(path)[1] == '.py'
+
+
+def lint(paths):
+  """Run python's linter on |paths| if it is a python file. Return False if it
+  fails linting."""
+  paths = [path for path in paths if is_python(path)]
+  if not paths:
+    return True
+
+  command = ['python3', '-m', 'pylint', '-j', '0']
+  command.extend(paths)
+
+  returncode = subprocess.run(command, check=False).returncode
+  return returncode == 0
+
+
+def yapf(paths, validate=True):
+  """Do yapf on |path| if it is Python file. Only validates format if
+  |validate| otherwise, formats the file. Returns False if validation
+  or formatting fails."""
+  paths = [path for path in paths if is_python(path)]
+  if not paths:
+    return True
+
+  validate_argument = '-d' if validate else '-i'
+  command = ['yapf', validate_argument, '-p']
+  command.extend(paths)
+
+  returncode = subprocess.run(command, check=False).returncode
+  return returncode == 0
+
+
+def get_changed_files():
+  """Return a list of absolute paths of files changed in this git branch."""
+  # FIXME: This doesn't work if branch is behind master.
+  diff_command = ['git', 'diff', '--name-only', 'FETCH_HEAD']
+  return [
+      os.path.abspath(path)
+      for path in subprocess.check_output(diff_command).decode().splitlines()
+      if os.path.isfile(path)
+  ]
+
+
+def main():
+  """Check changes on a branch for common issues before submitting."""
+  # Get program arguments.
+  parser = argparse.ArgumentParser(description='Presubmit script for oss-fuzz.')
+  parser.add_argument('command',
+                      choices=['format', 'lint', 'license'],
+                      nargs='?')
+  args = parser.parse_args()
+
+  changed_files = get_changed_files()
+
+  os.chdir(_SRC_ROOT)
+
+  # Do one specific check if the user asked for it.
+  if args.command == 'format':
+    success = yapf(changed_files, False)
+    return bool_to_returncode(success)
+
+  if args.command == 'lint':
+    success = lint(changed_files)
+    return bool_to_returncode(success)
+
+  if args.command == 'license':
+    success = check_license(changed_files)
+    return bool_to_returncode(success)
+
+  # Otherwise, do all of them.
+  success = do_checks(changed_files)
+  return bool_to_returncode(success)
+
+
+if __name__ == '__main__':
+  sys.exit(main())