Upgrade Antlr to 4.11 and vendor the runtime

.coveragerc

@@ -4,7 +4,9 @@ omit =
     *tests*
     docs/*
     omegaconf/grammar/gen/*
+    omegaconf/vendor/*
     omegaconf/version.py
+    omegaconf/typing.py
     .stubs
 
 [report]

.flake8

@@ -1,5 +1,5 @@
 [flake8]
-exclude = .git,.nox,.tox,omegaconf/grammar/gen,build
+exclude = .git,.nox,.tox,omegaconf/grammar/gen,build,omegaconf/vendor
 max-line-length = 119
 select = E,F,W,C
 ignore=W503,E203

.isort.cfg

@@ -7,4 +7,4 @@ line_length=88
 ensure_newline_before_comments=True
 known_third_party=attr,pytest
 known_first_party=omegaconf
-skip=.eggs,.nox,omegaconf/grammar/gen,build
+skip=.eggs,.nox,omegaconf/grammar/gen,build,omegaconf/vendor

build_helpers/build_helpers.py

@@ -6,6 +6,7 @@
 import shutil
 import subprocess
 import sys
+from functools import partial
 from pathlib import Path
 from typing import List, Optional
 
@@ -30,7 +31,7 @@ def run(self) -> None:
             command = [
                 "java",
                 "-jar",
-                str(build_dir / "bin" / "antlr-4.9.3-complete.jar"),
+                str(build_dir / "bin" / "antlr-4.11.1-complete.jar"),
                 "-Dlanguage=Python3",
                 "-o",
                 str(project_root / "omegaconf" / "grammar" / "gen"),
@@ -46,12 +47,44 @@ def run(self) -> None:
 
             subprocess.check_call(command)
 
+            self.announce(
+                "Fixing imports for generated parsers",
+                level=distutils.log.INFO,
+            )
+            self._fix_imports()
+
     def initialize_options(self) -> None:
         pass
 
     def finalize_options(self) -> None:
         pass
 
+    def _fix_imports(self) -> None:
+        """Fix imports from the generated parsers to use the vendored antlr4 instead"""
+        build_dir = Path(__file__).parent.absolute()
+        project_root = build_dir.parent
+        lib = "antlr4"
+        pkgname = 'omegaconf.vendor'
+
+        replacements = [
+            partial(  # import antlr4 -> import omegaconf.vendor.antlr4
+                re.compile(r'(^\s*)import {}\n'.format(lib), flags=re.M).sub,
+                r'\1from {} import {}\n'.format(pkgname, lib)
+            ),
+            partial(  # from antlr4 -> from fomegaconf.vendor.antlr4
+                re.compile(r'(^\s*)from {}(\.|\s+)'.format(lib), flags=re.M).sub,
+                r'\1from {}.{}\2'.format(pkgname, lib)
+            ),
+        ]
+
+        path = project_root / "omegaconf" / "grammar" / "gen"
+        for item in path.iterdir():
+            if item.is_file() and item.name.endswith(".py"):
+                text = item.read_text('utf8')
+                for replacement in replacements:
+                    text = replacement(text)
+                item.write_text(text, 'utf8')
+
 
 class BuildPyCommand(build_py.build_py):  # pragma: no cover
     def run(self) -> None:

build_helpers/get_vendored.py

@@ -0,0 +1,121 @@
+import re
+import shutil
+import subprocess
+from functools import partial
+from itertools import chain
+from pathlib import Path
+from typing import Callable, FrozenSet, Generator, List, Set, Tuple, Union
+
+WHITELIST = {'README.txt', '__init__.py', 'vendor.txt'}
+
+
+def delete_all(*paths: Path, whitelist: Union[Set[str], FrozenSet[str]] = frozenset()) -> None:
+    """Clear all the items in each of the indicated paths, except for elements listed
+    in the whitelist"""
+    for item in paths:
+        if item.is_dir():
+            shutil.rmtree(item, ignore_errors=True)
+        elif item.is_file() and item.name not in whitelist:
+            item.unlink()
+
+
+def iter_subtree(path: Path, depth: int = 0) -> Generator[Tuple[Path, int], None, None]:
+    """Recursively yield all files in a subtree, depth-first"""
+    if not path.is_dir():
+        if path.is_file():
+            yield path, depth
+        return
+    for item in path.iterdir():
+        if item.is_dir():
+            yield from iter_subtree(item, depth + 1)
+        elif item.is_file():
+            yield item, depth + 1
+
+
+def patch_vendor_imports(file: Path, replacements: List[Callable[[str], str]]) -> None:
+    """Apply a list of replacements/patches to a given file"""
+    text = file.read_text('utf8')
+    for replacement in replacements:
+        text = replacement(text)
+    file.write_text(text, 'utf8')
+
+
+def find_vendored_libs(vendor_dir: Path, whitelist: Set[str]) -> Tuple[List[str], List[Path]]:
+    vendored_libs = []
+    paths = []
+    for item in vendor_dir.iterdir():
+        if item.is_dir():
+            vendored_libs.append(item.name)
+        elif item.is_file() and item.name not in whitelist:
+            vendored_libs.append(item.stem)  # without extension
+        else:  # not a dir or a file not in the whilelist
+            continue
+        paths.append(item)
+    return vendored_libs, paths
+
+
+def vendor(vendor_dir: Path, relative_imports: bool = False) -> None:
+    # target package is <parent>.<vendor_dir>; foo/vendor -> foo.vendor
+    pkgname = f'{vendor_dir.parent.name}.{vendor_dir.name}'
+
+    # remove everything
+    delete_all(*vendor_dir.iterdir(), whitelist=WHITELIST)
+
+    # install with pip
+    subprocess.run([
+        'pip', 'install', '-t', str(vendor_dir),
+        '-r', str(vendor_dir / 'vendor.txt'),
+        '--no-compile', '--no-deps'
+    ])
+
+    # delete stuff that's not needed
+    delete_all(
+        *vendor_dir.glob('*.dist-info'),
+        *vendor_dir.glob('*.egg-info'),
+        vendor_dir / 'bin')
+
+    vendored_libs, paths = find_vendored_libs(vendor_dir, WHITELIST)
+
+    if not relative_imports:
+        replacements: List[Callable[[str], str]] = []
+        for lib in vendored_libs:
+            replacements += (
+                partial(  # import bar -> import foo.vendor.bar
+                    re.compile(r'(^\s*)import {}\n'.format(lib), flags=re.M).sub,
+                    r'\1from {} import {}\n'.format(pkgname, lib)
+                ),
+                partial(  # from bar -> from foo.vendor.bar
+                    re.compile(r'(^\s*)from {}(\.|\s+)'.format(lib), flags=re.M).sub,
+                    r'\1from {}.{}\2'.format(pkgname, lib)
+                ),
+            )
+
+    for file, depth in chain.from_iterable(map(iter_subtree, paths)):
+        if relative_imports:
+            pkgname = '.' * (depth - 1)
+            replacements = []
+            for lib in vendored_libs:
+                replacements += (
+                    partial(
+                        re.compile(r'(^\s*)import {}\n'.format(lib), flags=re.M).sub,
+                        r'\1from {} import {}\n'.format(pkgname, "")
+                    ),
+                    partial(
+                        re.compile(r'^from {}(\s+)'.format(lib), flags=re.M).sub,
+                        r'from .{}\1'.format(pkgname)
+                    ),
+                    partial(
+                        re.compile(r'(^\s*)from {}(\.+)'.format(lib), flags=re.M).sub,
+                        r'\1from {}\2'.format(pkgname)
+                    ),
+                )
+        patch_vendor_imports(file, replacements)
+
+
+if __name__ == '__main__':
+    # this assumes this is a script in `build_helpers`
+    here = Path('__file__').resolve().parent
+    vendor_dir = here / 'omegaconf' / 'vendor'
+    assert (vendor_dir / 'vendor.txt').exists(), 'omegaconf/vendor/vendor.txt file not found'
+    assert (vendor_dir / '__init__.py').exists(), 'omegaconf/vendor/__init__.py file not found'
+    vendor(vendor_dir, relative_imports=True)