diff --git a/cc/gen_stub_libs.py b/cc/gen_stub_libs.py
index 4b7c244..9b40415 100755
--- a/cc/gen_stub_libs.py
+++ b/cc/gen_stub_libs.py
@@ -16,6 +16,7 @@
 #
 """Generates source for stub shared libraries for the NDK."""
 import argparse
+import logging
 import os
 import re
 
@@ -30,45 +31,28 @@
 )
 
 
-class Scope(object):
-    """Enum for version script scope.
-
-    Top: Top level of the file.
-    Global: In a version and visibility section where symbols should be visible
-            to the NDK.
-    Local: In a visibility section of a public version where symbols should be
-           hidden to the NDK.
-    Private: In a version where symbols should not be visible to the NDK.
-    """
-    Top = 1
-    Global = 2
-    Local = 3
-    Private = 4
-
-
-class Stack(object):
-    """Basic stack implementation."""
-    def __init__(self):
-        self.stack = []
-
-    def push(self, obj):
-        """Push an item on to the stack."""
-        self.stack.append(obj)
-
-    def pop(self):
-        """Remove and return the item on the top of the stack."""
-        return self.stack.pop()
-
-    @property
-    def top(self):
-        """Return the top of the stack."""
-        return self.stack[-1]
+def logger():
+    """Return the main logger for this module."""
+    return logging.getLogger(__name__)
 
 
 def get_tags(line):
     """Returns a list of all tags on this line."""
     _, _, all_tags = line.strip().partition('#')
-    return re.split(r'\s+', all_tags)
+    return [e for e in re.split(r'\s+', all_tags) if e.strip()]
+
+
+def get_tag_value(tag):
+    """Returns the value of a key/value tag.
+
+    Raises:
+        ValueError: Tag is not a key/value type tag.
+
+    Returns: Value part of tag as a string.
+    """
+    if '=' not in tag:
+        raise ValueError('Not a key/value tag: ' + tag)
+    return tag.partition('=')[2]
 
 
 def version_is_private(version):
@@ -87,82 +71,11 @@
         return True
     if not symbol_in_arch(tags, arch):
         return True
-    if not symbol_in_version(tags, arch, api):
+    if not symbol_in_api(tags, arch, api):
         return True
     return False
 
 
-def enter_version(scope, line, version_file, arch, api):
-    """Enters a new version block scope."""
-    if scope.top != Scope.Top:
-        raise RuntimeError('Encountered nested version block.')
-
-    # Entering a new version block. By convention symbols with versions ending
-    # with "_PRIVATE" or "_PLATFORM" are not included in the NDK.
-    version_name = line.split('{')[0].strip()
-    tags = get_tags(line)
-    if should_omit_version(version_name, tags, arch, api):
-        scope.push(Scope.Private)
-    else:
-        scope.push(Scope.Global)  # By default symbols are visible.
-        version_file.write(line)
-
-
-def leave_version(scope, line, version_file):
-    """Leave a version block scope."""
-    # There is no close to a visibility section, just the end of the version or
-    # a new visiblity section.
-    assert scope.top in (Scope.Global, Scope.Local, Scope.Private)
-    if scope.top != Scope.Private:
-        version_file.write(line)
-    scope.pop()
-    assert scope.top == Scope.Top
-
-
-def enter_visibility(scope, line, version_file):
-    """Enters a new visibility block scope."""
-    leave_visibility(scope)
-    version_file.write(line)
-    visibility = line.split(':')[0].strip()
-    if visibility == 'local':
-        scope.push(Scope.Local)
-    elif visibility == 'global':
-        scope.push(Scope.Global)
-    else:
-        raise RuntimeError('Unknown visiblity label: ' + visibility)
-
-
-def leave_visibility(scope):
-    """Leaves a visibility block scope."""
-    assert scope.top in (Scope.Global, Scope.Local)
-    scope.pop()
-    assert scope.top == Scope.Top
-
-
-def handle_top_scope(scope, line, version_file, arch, api):
-    """Processes a line in the top level scope."""
-    if '{' in line:
-        enter_version(scope, line, version_file, arch, api)
-    else:
-        raise RuntimeError('Unexpected contents at top level: ' + line)
-
-
-def handle_private_scope(scope, line, version_file):
-    """Eats all input."""
-    if '}' in line:
-        leave_version(scope, line, version_file)
-
-
-def handle_local_scope(scope, line, version_file):
-    """Passes through input."""
-    if ':' in line:
-        enter_visibility(scope, line, version_file)
-    elif '}' in line:
-        leave_version(scope, line, version_file)
-    else:
-        version_file.write(line)
-
-
 def symbol_in_arch(tags, arch):
     """Returns true if the symbol is present for the given architecture."""
     has_arch_tags = False
@@ -178,8 +91,8 @@
     return not has_arch_tags
 
 
-def symbol_in_version(tags, arch, version):
-    """Returns true if the symbol is present for the given version."""
+def symbol_in_api(tags, arch, api):
+    """Returns true if the symbol is present for the given API level."""
     introduced_tag = None
     arch_specific = False
     for tag in tags:
@@ -191,7 +104,7 @@
             arch_specific = True
         elif tag == 'future':
             # This symbol is not in any released API level.
-            # TODO(danalbert): These need to be emitted for version == current.
+            # TODO(danalbert): These need to be emitted for api == current.
             # That's not a construct we have yet, so just skip it for now.
             return False
 
@@ -200,66 +113,204 @@
         # available.
         return True
 
-    # The tag is a key=value pair, and we only care about the value now.
-    _, _, version_str = introduced_tag.partition('=')
-    return version >= int(version_str)
+    return api >= int(get_tag_value(introduced_tag))
 
 
-def handle_global_scope(scope, line, src_file, version_file, arch, api):
-    """Emits present symbols to the version file and stub source file."""
-    if ':' in line:
-        enter_visibility(scope, line, version_file)
-        return
-    if '}' in line:
-        leave_version(scope, line, version_file)
-        return
+def symbol_versioned_in_api(tags, api):
+    """Returns true if the symbol should be versioned for the given API.
 
-    if ';' not in line:
-        raise RuntimeError('Expected ; to terminate symbol: ' + line)
-    if '*' in line:
-        raise RuntimeError('Wildcard global symbols are not permitted.')
+    This models the `versioned=API` tag. This should be a very uncommonly
+    needed tag, and is really only needed to fix versioning mistakes that are
+    already out in the wild.
 
-    # Line is now in the format "<symbol-name>; # tags"
-    # Tags are whitespace separated.
-    symbol_name, _, rest = line.strip().partition(';')
-    tags = get_tags(line)
-
-    if not symbol_in_arch(tags, arch):
-        return
-    if not symbol_in_version(tags, arch, api):
-        return
-
-    if 'var' in tags:
-        src_file.write('int {} = 0;\n'.format(symbol_name))
-    else:
-        src_file.write('void {}() {{}}\n'.format(symbol_name))
-    version_file.write(line)
+    For example, some of libc's __aeabi_* functions were originally placed in
+    the private version, but that was incorrect. They are now in LIBC_N, but
+    when building against any version prior to N we need the symbol to be
+    unversioned (otherwise it won't resolve on M where it is private).
+    """
+    for tag in tags:
+        if tag.startswith('versioned='):
+            return api >= int(get_tag_value(tag))
+    # If there is no "versioned" tag, the tag has been versioned for as long as
+    # it was introduced.
+    return True
 
 
-def generate(symbol_file, src_file, version_file, arch, api):
-    """Generates the stub source file and version script."""
-    scope = Stack()
-    scope.push(Scope.Top)
-    for line in symbol_file:
-        if line.strip() == '' or line.strip().startswith('#'):
-            version_file.write(line)
-        elif scope.top == Scope.Top:
-            handle_top_scope(scope, line, version_file, arch, api)
-        elif scope.top == Scope.Private:
-            handle_private_scope(scope, line, version_file)
-        elif scope.top == Scope.Local:
-            handle_local_scope(scope, line, version_file)
-        elif scope.top == Scope.Global:
-            handle_global_scope(scope, line, src_file, version_file, arch, api)
+class ParseError(RuntimeError):
+    """An error that occurred while parsing a symbol file."""
+    pass
+
+
+class Version(object):
+    """A version block of a symbol file."""
+    def __init__(self, name, base, tags, symbols):
+        self.name = name
+        self.base = base
+        self.tags = tags
+        self.symbols = symbols
+
+    def __eq__(self, other):
+        if self.name != other.name:
+            return False
+        if self.base != other.base:
+            return False
+        if self.tags != other.tags:
+            return False
+        if self.symbols != other.symbols:
+            return False
+        return True
+
+
+class Symbol(object):
+    """A symbol definition from a symbol file."""
+    def __init__(self, name, tags):
+        self.name = name
+        self.tags = tags
+
+    def __eq__(self, other):
+        return self.name == other.name and set(self.tags) == set(other.tags)
+
+
+class SymbolFileParser(object):
+    """Parses NDK symbol files."""
+    def __init__(self, input_file):
+        self.input_file = input_file
+        self.current_line = None
+
+    def parse(self):
+        """Parses the symbol file and returns a list of Version objects."""
+        versions = []
+        while self.next_line() != '':
+            if '{' in self.current_line:
+                versions.append(self.parse_version())
+            else:
+                raise ParseError(
+                    'Unexpected contents at top level: ' + self.current_line)
+        return versions
+
+    def parse_version(self):
+        """Parses a single version section and returns a Version object."""
+        name = self.current_line.split('{')[0].strip()
+        tags = get_tags(self.current_line)
+        symbols = []
+        global_scope = True
+        while self.next_line() != '':
+            if '}' in self.current_line:
+                # Line is something like '} BASE; # tags'. Both base and tags
+                # are optional here.
+                base = self.current_line.partition('}')[2]
+                base = base.partition('#')[0].strip()
+                if not base.endswith(';'):
+                    raise ParseError(
+                        'Unterminated version block (expected ;).')
+                base = base.rstrip(';').rstrip()
+                if base == '':
+                    base = None
+                return Version(name, base, tags, symbols)
+            elif ':' in self.current_line:
+                visibility = self.current_line.split(':')[0].strip()
+                if visibility == 'local':
+                    global_scope = False
+                elif visibility == 'global':
+                    global_scope = True
+                else:
+                    raise ParseError('Unknown visiblity label: ' + visibility)
+            elif global_scope:
+                symbols.append(self.parse_symbol())
+            else:
+                # We're in a hidden scope. Ignore everything.
+                pass
+        raise ParseError('Unexpected EOF in version block.')
+
+    def parse_symbol(self):
+        """Parses a single symbol line and returns a Symbol object."""
+        if ';' not in self.current_line:
+            raise ParseError(
+                'Expected ; to terminate symbol: ' + self.current_line)
+        if '*' in self.current_line:
+            raise ParseError(
+                'Wildcard global symbols are not permitted.')
+        # Line is now in the format "<symbol-name>; # tags"
+        name, _, _ = self.current_line.strip().partition(';')
+        tags = get_tags(self.current_line)
+        return Symbol(name, tags)
+
+    def next_line(self):
+        """Returns the next non-empty non-comment line.
+
+        A return value of '' indicates EOF.
+        """
+        line = self.input_file.readline()
+        while line.strip() == '' or line.strip().startswith('#'):
+            line = self.input_file.readline()
+
+            # We want to skip empty lines, but '' indicates EOF.
+            if line == '':
+                break
+        self.current_line = line
+        return self.current_line
+
+
+class Generator(object):
+    """Output generator that writes stub source files and version scripts."""
+    def __init__(self, src_file, version_script, arch, api):
+        self.src_file = src_file
+        self.version_script = version_script
+        self.arch = arch
+        self.api = api
+
+    def write(self, versions):
+        """Writes all symbol data to the output files."""
+        for version in versions:
+            self.write_version(version)
+
+    def write_version(self, version):
+        """Writes a single version block's data to the output files."""
+        name = version.name
+        tags = version.tags
+        if should_omit_version(name, tags, self.arch, self.api):
+            return
+
+        version_empty = True
+        pruned_symbols = []
+        for symbol in version.symbols:
+            if not symbol_in_arch(symbol.tags, self.arch):
+                continue
+            if not symbol_in_api(symbol.tags, self.arch, self.api):
+                continue
+
+            if symbol_versioned_in_api(symbol.tags, self.api):
+                version_empty = False
+            pruned_symbols.append(symbol)
+
+        if len(pruned_symbols) > 0:
+            if not version_empty:
+                self.version_script.write(version.name + ' {\n')
+                self.version_script.write('    global:\n')
+            for symbol in pruned_symbols:
+                if symbol_versioned_in_api(symbol.tags, self.api):
+                    self.version_script.write('        ' + symbol.name + ';\n')
+
+                if 'var' in symbol.tags:
+                    self.src_file.write('int {} = 0;\n'.format(symbol.name))
+                else:
+                    self.src_file.write('void {}() {{}}\n'.format(symbol.name))
+
+            if not version_empty:
+                base = '' if version.base is None else ' ' + version.base
+                self.version_script.write('}' + base + ';\n')
 
 
 def parse_args():
     """Parses and returns command line arguments."""
     parser = argparse.ArgumentParser()
 
-    parser.add_argument('--api', type=int, help='API level being targeted.')
+    parser.add_argument('-v', '--verbose', action='count', default=0)
+
     parser.add_argument(
-        '--arch', choices=ALL_ARCHITECTURES,
+        '--api', type=int, required=True, help='API level being targeted.')
+    parser.add_argument(
+        '--arch', choices=ALL_ARCHITECTURES, required=True,
         help='Architecture being targeted.')
 
     parser.add_argument(
@@ -278,11 +329,19 @@
     """Program entry point."""
     args = parse_args()
 
+    verbose_map = (logging.WARNING, logging.INFO, logging.DEBUG)
+    verbosity = args.verbose
+    if verbosity > 2:
+        verbosity = 2
+    logging.basicConfig(level=verbose_map[verbosity])
+
     with open(args.symbol_file) as symbol_file:
-        with open(args.stub_src, 'w') as src_file:
-            with open(args.version_script, 'w') as version_file:
-                generate(symbol_file, src_file, version_file, args.arch,
-                         args.api)
+        versions = SymbolFileParser(symbol_file).parse()
+
+    with open(args.stub_src, 'w') as src_file:
+        with open(args.version_script, 'w') as version_file:
+            generator = Generator(src_file, version_file, args.arch, args.api)
+            generator.write(versions)
 
 
 if __name__ == '__main__':
diff --git a/cc/test_gen_stub_libs.py b/cc/test_gen_stub_libs.py
new file mode 100755
index 0000000..8436a48
--- /dev/null
+++ b/cc/test_gen_stub_libs.py
@@ -0,0 +1,440 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2016 The Android Open Source Project
+#
+# 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.
+#
+"""Tests for gen_stub_libs.py."""
+import cStringIO
+import textwrap
+import unittest
+
+import gen_stub_libs as gsl
+
+
+# pylint: disable=missing-docstring
+
+
+class TagsTest(unittest.TestCase):
+    def test_get_tags_no_tags(self):
+        self.assertEqual([], gsl.get_tags(''))
+        self.assertEqual([], gsl.get_tags('foo bar baz'))
+
+    def test_get_tags(self):
+        self.assertEqual(['foo', 'bar'], gsl.get_tags('# foo bar'))
+        self.assertEqual(['bar', 'baz'], gsl.get_tags('foo # bar baz'))
+
+    def test_get_tag_value(self):
+        self.assertEqual('bar', gsl.get_tag_value('foo=bar'))
+        self.assertEqual('bar=baz', gsl.get_tag_value('foo=bar=baz'))
+        with self.assertRaises(ValueError):
+            gsl.get_tag_value('foo')
+
+
+class PrivateVersionTest(unittest.TestCase):
+    def test_version_is_private(self):
+        self.assertFalse(gsl.version_is_private('foo'))
+        self.assertFalse(gsl.version_is_private('PRIVATE'))
+        self.assertFalse(gsl.version_is_private('PLATFORM'))
+        self.assertFalse(gsl.version_is_private('foo_private'))
+        self.assertFalse(gsl.version_is_private('foo_platform'))
+        self.assertFalse(gsl.version_is_private('foo_PRIVATE_'))
+        self.assertFalse(gsl.version_is_private('foo_PLATFORM_'))
+
+        self.assertTrue(gsl.version_is_private('foo_PRIVATE'))
+        self.assertTrue(gsl.version_is_private('foo_PLATFORM'))
+
+
+class SymbolPresenceTest(unittest.TestCase):
+    def test_symbol_in_arch(self):
+        self.assertTrue(gsl.symbol_in_arch([], 'arm'))
+        self.assertTrue(gsl.symbol_in_arch(['arm'], 'arm'))
+
+        self.assertFalse(gsl.symbol_in_arch(['x86'], 'arm'))
+
+    def test_symbol_in_api(self):
+        self.assertTrue(gsl.symbol_in_api([], 'arm', 9))
+        self.assertTrue(gsl.symbol_in_api(['introduced=9'], 'arm', 9))
+        self.assertTrue(gsl.symbol_in_api(['introduced=9'], 'arm', 14))
+        self.assertTrue(gsl.symbol_in_api(['introduced-arm=9'], 'arm', 14))
+        self.assertTrue(gsl.symbol_in_api(['introduced-arm=9'], 'arm', 14))
+        self.assertTrue(gsl.symbol_in_api(['introduced-x86=14'], 'arm', 9))
+        self.assertTrue(gsl.symbol_in_api(
+            ['introduced-arm=9', 'introduced-x86=21'], 'arm', 14))
+        self.assertTrue(gsl.symbol_in_api(
+            ['introduced=9', 'introduced-x86=21'], 'arm', 14))
+        self.assertTrue(gsl.symbol_in_api(
+            ['introduced=21', 'introduced-arm=9'], 'arm', 14))
+
+        self.assertFalse(gsl.symbol_in_api(['introduced=14'], 'arm', 9))
+        self.assertFalse(gsl.symbol_in_api(['introduced-arm=14'], 'arm', 9))
+        self.assertFalse(gsl.symbol_in_api(['future'], 'arm', 9))
+        self.assertFalse(gsl.symbol_in_api(
+            ['introduced=9', 'future'], 'arm', 14))
+        self.assertFalse(gsl.symbol_in_api(
+            ['introduced-arm=9', 'future'], 'arm', 14))
+        self.assertFalse(gsl.symbol_in_api(
+            ['introduced-arm=21', 'introduced-x86=9'], 'arm', 14))
+        self.assertFalse(gsl.symbol_in_api(
+            ['introduced=9', 'introduced-arm=21'], 'arm', 14))
+        self.assertFalse(gsl.symbol_in_api(
+            ['introduced=21', 'introduced-x86=9'], 'arm', 14))
+
+        # Interesting edge case: this symbol should be omitted from the
+        # library, but this call should still return true because none of the
+        # tags indiciate that it's not present in this API level.
+        self.assertTrue(gsl.symbol_in_api(['x86'], 'arm', 9))
+
+    def test_verioned_in_api(self):
+        self.assertTrue(gsl.symbol_versioned_in_api([], 9))
+        self.assertTrue(gsl.symbol_versioned_in_api(['versioned=9'], 9))
+        self.assertTrue(gsl.symbol_versioned_in_api(['versioned=9'], 14))
+
+        self.assertFalse(gsl.symbol_versioned_in_api(['versioned=14'], 9))
+
+
+class OmitVersionTest(unittest.TestCase):
+    def test_omit_private(self):
+        self.assertFalse(gsl.should_omit_version('foo', [], 'arm', 9))
+
+        self.assertTrue(gsl.should_omit_version('foo_PRIVATE', [], 'arm', 9))
+        self.assertTrue(gsl.should_omit_version('foo_PLATFORM', [], 'arm', 9))
+
+    def test_omit_arch(self):
+        self.assertFalse(gsl.should_omit_version('foo', [], 'arm', 9))
+        self.assertFalse(gsl.should_omit_version('foo', ['arm'], 'arm', 9))
+
+        self.assertTrue(gsl.should_omit_version('foo', ['x86'], 'arm', 9))
+
+    def test_omit_api(self):
+        self.assertFalse(gsl.should_omit_version('foo', [], 'arm', 9))
+        self.assertFalse(
+            gsl.should_omit_version('foo', ['introduced=9'], 'arm', 9))
+
+        self.assertTrue(
+            gsl.should_omit_version('foo', ['introduced=14'], 'arm', 9))
+
+
+class SymbolFileParseTest(unittest.TestCase):
+    def test_next_line(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            foo
+
+            bar
+            # baz
+            qux
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+        self.assertIsNone(parser.current_line)
+
+        self.assertEqual('foo', parser.next_line().strip())
+        self.assertEqual('foo', parser.current_line.strip())
+
+        self.assertEqual('bar', parser.next_line().strip())
+        self.assertEqual('bar', parser.current_line.strip())
+
+        self.assertEqual('qux', parser.next_line().strip())
+        self.assertEqual('qux', parser.current_line.strip())
+
+        self.assertEqual('', parser.next_line())
+        self.assertEqual('', parser.current_line)
+
+    def test_parse_version(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            VERSION_1 { # foo bar
+                baz;
+                qux; # woodly doodly
+            };
+
+            VERSION_2 {
+            } VERSION_1; # asdf
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+
+        parser.next_line()
+        version = parser.parse_version()
+        self.assertEqual('VERSION_1', version.name)
+        self.assertIsNone(version.base)
+        self.assertEqual(['foo', 'bar'], version.tags)
+
+        expected_symbols = [
+            gsl.Symbol('baz', []),
+            gsl.Symbol('qux', ['woodly', 'doodly']),
+        ]
+        self.assertEqual(expected_symbols, version.symbols)
+
+        parser.next_line()
+        version = parser.parse_version()
+        self.assertEqual('VERSION_2', version.name)
+        self.assertEqual('VERSION_1', version.base)
+        self.assertEqual([], version.tags)
+
+    def test_parse_version_eof(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            VERSION_1 {
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+        parser.next_line()
+        with self.assertRaises(gsl.ParseError):
+            parser.parse_version()
+
+    def test_unknown_scope_label(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            VERSION_1 {
+                foo:
+            }
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+        parser.next_line()
+        with self.assertRaises(gsl.ParseError):
+            parser.parse_version()
+
+    def test_parse_symbol(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            foo;
+            bar; # baz qux
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+
+        parser.next_line()
+        symbol = parser.parse_symbol()
+        self.assertEqual('foo', symbol.name)
+        self.assertEqual([], symbol.tags)
+
+        parser.next_line()
+        symbol = parser.parse_symbol()
+        self.assertEqual('bar', symbol.name)
+        self.assertEqual(['baz', 'qux'], symbol.tags)
+
+    def test_wildcard_symbol_global(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            VERSION_1 {
+                *;
+            };
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+        parser.next_line()
+        with self.assertRaises(gsl.ParseError):
+            parser.parse_version()
+
+    def test_wildcard_symbol_local(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            VERSION_1 {
+                local:
+                    *;
+            };
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+        parser.next_line()
+        version = parser.parse_version()
+        self.assertEqual([], version.symbols)
+
+    def test_missing_semicolon(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            VERSION_1 {
+                foo
+            };
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+        parser.next_line()
+        with self.assertRaises(gsl.ParseError):
+            parser.parse_version()
+
+    def test_parse_fails_invalid_input(self):
+        with self.assertRaises(gsl.ParseError):
+            input_file = cStringIO.StringIO('foo')
+            parser = gsl.SymbolFileParser(input_file)
+            parser.parse()
+
+    def test_parse(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            VERSION_1 {
+                local:
+                    hidden1;
+                global:
+                    foo;
+                    bar; # baz
+            };
+
+            VERSION_2 { # wasd
+                # Implicit global scope.
+                    woodly;
+                    doodly; # asdf
+                local:
+                    qwerty;
+            } VERSION_1;
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+        versions = parser.parse()
+
+        expected = [
+            gsl.Version('VERSION_1', None, [], [
+                gsl.Symbol('foo', []),
+                gsl.Symbol('bar', ['baz']),
+            ]),
+            gsl.Version('VERSION_2', 'VERSION_1', ['wasd'], [
+                gsl.Symbol('woodly', []),
+                gsl.Symbol('doodly', ['asdf']),
+            ]),
+        ]
+
+        self.assertEqual(expected, versions)
+
+
+class GeneratorTest(unittest.TestCase):
+    def test_omit_version(self):
+        # Thorough testing of the cases involved here is handled by
+        # OmitVersionTest, PrivateVersionTest, and SymbolPresenceTest.
+        src_file = cStringIO.StringIO()
+        version_file = cStringIO.StringIO()
+        generator = gsl.Generator(src_file, version_file, 'arm', 9)
+
+        version = gsl.Version('VERSION_PRIVATE', None, [], [
+            gsl.Symbol('foo', []),
+        ])
+        generator.write_version(version)
+        self.assertEqual('', src_file.getvalue())
+        self.assertEqual('', version_file.getvalue())
+
+        version = gsl.Version('VERSION', None, ['x86'], [
+            gsl.Symbol('foo', []),
+        ])
+        generator.write_version(version)
+        self.assertEqual('', src_file.getvalue())
+        self.assertEqual('', version_file.getvalue())
+
+        version = gsl.Version('VERSION', None, ['introduced=14'], [
+            gsl.Symbol('foo', []),
+        ])
+        generator.write_version(version)
+        self.assertEqual('', src_file.getvalue())
+        self.assertEqual('', version_file.getvalue())
+
+    def test_omit_symbol(self):
+        # Thorough testing of the cases involved here is handled by
+        # SymbolPresenceTest.
+        src_file = cStringIO.StringIO()
+        version_file = cStringIO.StringIO()
+        generator = gsl.Generator(src_file, version_file, 'arm', 9)
+
+        version = gsl.Version('VERSION_1', None, [], [
+            gsl.Symbol('foo', ['x86']),
+        ])
+        generator.write_version(version)
+        self.assertEqual('', src_file.getvalue())
+        self.assertEqual('', version_file.getvalue())
+
+        version = gsl.Version('VERSION_1', None, [], [
+            gsl.Symbol('foo', ['introduced=14']),
+        ])
+        generator.write_version(version)
+        self.assertEqual('', src_file.getvalue())
+        self.assertEqual('', version_file.getvalue())
+
+    def test_write(self):
+        src_file = cStringIO.StringIO()
+        version_file = cStringIO.StringIO()
+        generator = gsl.Generator(src_file, version_file, 'arm', 9)
+
+        versions = [
+            gsl.Version('VERSION_1', None, [], [
+                gsl.Symbol('foo', []),
+                gsl.Symbol('bar', ['var']),
+            ]),
+            gsl.Version('VERSION_2', 'VERSION_1', [], [
+                gsl.Symbol('baz', []),
+            ]),
+            gsl.Version('VERSION_3', 'VERSION_1', [], [
+                gsl.Symbol('qux', ['versioned=14']),
+            ]),
+        ]
+
+        generator.write(versions)
+        expected_src = textwrap.dedent("""\
+            void foo() {}
+            int bar = 0;
+            void baz() {}
+            void qux() {}
+        """)
+        self.assertEqual(expected_src, src_file.getvalue())
+
+        expected_version = textwrap.dedent("""\
+            VERSION_1 {
+                global:
+                    foo;
+                    bar;
+            };
+            VERSION_2 {
+                global:
+                    baz;
+            } VERSION_1;
+        """)
+        self.assertEqual(expected_version, version_file.getvalue())
+
+
+class IntegrationTest(unittest.TestCase):
+    def test_integration(self):
+        input_file = cStringIO.StringIO(textwrap.dedent("""\
+            VERSION_1 {
+                global:
+                    foo; # var
+                    bar; # x86
+                local:
+                    *;
+            };
+
+            VERSION_2 { # arm
+                baz; # introduced=9
+                qux; # versioned=14
+            } VERSION_1;
+
+            VERSION_3 { # introduced=14
+                woodly;
+                doodly; # var
+            } VERSION_2;
+        """))
+        parser = gsl.SymbolFileParser(input_file)
+        versions = parser.parse()
+
+        src_file = cStringIO.StringIO()
+        version_file = cStringIO.StringIO()
+        generator = gsl.Generator(src_file, version_file, 'arm', 9)
+        generator.write(versions)
+
+        expected_src = textwrap.dedent("""\
+            int foo = 0;
+            void baz() {}
+            void qux() {}
+        """)
+        self.assertEqual(expected_src, src_file.getvalue())
+
+        expected_version = textwrap.dedent("""\
+            VERSION_1 {
+                global:
+                    foo;
+            };
+            VERSION_2 {
+                global:
+                    baz;
+            } VERSION_1;
+        """)
+        self.assertEqual(expected_version, version_file.getvalue())
+
+
+def main():
+    suite = unittest.TestLoader().loadTestsFromName(__name__)
+    unittest.TextTestRunner(verbosity=3).run(suite)
+
+
+if __name__ == '__main__':
+    main()