implement exports literal in jvm_target

src/python/pants/backend/jvm/targets/jvm_target.py

@@ -13,8 +13,10 @@
 from pants.backend.jvm.targets.jar_library import JarLibrary
 from pants.backend.jvm.targets.jarable import Jarable
 from pants.base.deprecated import deprecated_conditional
+from pants.base.exceptions import TargetDefinitionException
 from pants.base.payload import Payload
 from pants.base.payload_field import ExcludesField, PrimitiveField, SetOfPrimitivesField
+from pants.build_graph.address import Address
 from pants.build_graph.resources import Resources
 from pants.build_graph.target import Target
 from pants.util.memo import memoized_property
@@ -40,6 +42,7 @@ def __init__(self,
                services=None,
                platform=None,
                strict_deps=None,
+               exports=None,
                fatal_warnings=None,
                zinc_file_manager=None,
                # Some subclasses can have both .java and .scala sources
@@ -75,6 +78,14 @@ def __init__(self,
                              at compilation time. This enforces that all direct deps of the target
                              are declared, and can improve compilation speed due to smaller
                              classpaths. Transitive deps are always provided at runtime.
+    :param list exports: A list of exported targets, which will be accessible to dependents even
+                         with strict_deps turned on. A common use case is for library targets to
+                         to export dependencies that it knows its dependents will need. Then any
+                         dependents of that library target will have access to those dependencies
+                         even when strict_deps is True. Note: exports is transitive, which means
+                         dependents have access to the closure of exports. An example will be that
+                         if A exports B, and B exports C, then any targets that depends on A will
+                         have access to both B and C.
     :param bool fatal_warnings: Whether to turn warnings into errors for this target.  If present,
                                 takes priority over the language's fatal-warnings option.
     :param bool zinc_file_manager: Whether to use zinc provided file manager that allows
@@ -98,6 +109,7 @@ def __init__(self,
       'excludes': excludes,
       'platform': PrimitiveField(platform),
       'strict_deps': PrimitiveField(strict_deps),
+      'exports': SetOfPrimitivesField(exports),
       'fatal_warnings': PrimitiveField(fatal_warnings),
       'zinc_file_manager': PrimitiveField(zinc_file_manager),
       'javac_plugins': SetOfPrimitivesField(javac_plugins),
@@ -125,6 +137,26 @@ def strict_deps(self):
     """
     return self.payload.strict_deps
 
+  @property
+  def exports(self):
+    """A list of exported targets, which will be accessible to dependents.
+
+    :return: See constructor.
+    :rtype: list
+    """
+    exports = []
+    for spec in self.payload.exports:
+      addr = Address.parse(spec, relative_to=self.address.spec_path)
+      target = self._build_graph.get_target(addr)
+      if target not in self.dependencies:
+        # This means the exported target was not injected before "self",
+        # thus it's not a valid export.
+        raise TargetDefinitionException(self,
+          'Invalid exports: "{}" is not a dependency of {}'.format(spec, self))
+      exports.append(target)
+
+    return exports
+
   @property
   def fatal_warnings(self):
     """If set, overrides the platform's default fatal_warnings setting.

src/python/pants/backend/jvm/tasks/jvm_compile/compile_context.py

@@ -13,23 +13,33 @@
 from pants.util.contextutil import open_zip
 
 
-def _resolve_aliases(target):
+def _resolve_strict_dependencies(target):
   for declared in target.dependencies:
     if type(declared) in (AliasTarget, Target):
       # Is an alias. Recurse to expand.
-      for r in _resolve_aliases(declared):
+      for r in _resolve_strict_dependencies(declared):
         yield r
     else:
       yield declared
 
+    for export in _resolve_exports(declared):
+      yield export
+
+
+def _resolve_exports(target):
+  for export in getattr(target, 'exports', []):
+    for exp in _resolve_exports(export):
+      yield exp
+    yield export
+
 
 def strict_dependencies(target, dep_context):
   """Compute the 'strict' compile target dependencies for this target.
 
   Results the declared dependencies of a target after alias expansion, with the addition
   of compiler plugins and their transitive deps, since compiletime is actually runtime for them.
   """
-  for declared in _resolve_aliases(target):
+  for declared in _resolve_strict_dependencies(target):
     if isinstance(declared, dep_context.compiler_plugin_types):
       for r in declared.closure(bfs=True, **dep_context.target_closure_kwargs):
         yield r

testprojects/tests/java/org/pantsbuild/testproject/exports/A.java

@@ -0,0 +1,9 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.exports;
+
+public class A {
+  public void foo_a() {
+  }
+}

testprojects/tests/java/org/pantsbuild/testproject/exports/B.java

@@ -0,0 +1,9 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.exports;
+
+public class B extends A {
+  public void foo_b() {
+  }
+}

testprojects/tests/java/org/pantsbuild/testproject/exports/BUILD

@@ -0,0 +1,27 @@
+java_library(
+  name='A',
+  sources = ['A.java'],
+)
+
+java_library(
+  name='B',
+  sources = ['B.java'],
+  dependencies=[':A'],
+  exports=[':A'],
+  strict_deps=True,
+)
+
+java_library(
+  name='C',
+  sources = ['C.java'],
+  dependencies=[':B'],
+  exports=[':B'],
+  strict_deps=True,
+)
+
+java_library(
+  name='D',
+  sources = ['D.java'],
+  dependencies=[':C'],
+  strict_deps=True,
+)

testprojects/tests/java/org/pantsbuild/testproject/exports/C.java

@@ -0,0 +1,9 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.exports;
+
+public class C extends B {
+  public void foo_c() {
+  }
+}

testprojects/tests/java/org/pantsbuild/testproject/exports/D.java

@@ -0,0 +1,11 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.exports;
+
+public class D {
+  public void foo_d() {
+    C c = new C();
+    c.foo_c();
+  }
+}

testprojects/tests/scala/org/pantsbuild/testproject/exports/A.scala

@@ -0,0 +1,9 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.exports;
+
+class A {
+  def foo_a() {
+  }
+}

testprojects/tests/scala/org/pantsbuild/testproject/exports/B.scala

@@ -0,0 +1,9 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.exports;
+
+class B extends A {
+  def foo_b() {
+  }
+}

testprojects/tests/scala/org/pantsbuild/testproject/exports/BUILD

@@ -0,0 +1,27 @@
+scala_library(
+  name='A',
+  sources = ['A.scala'],
+)
+
+scala_library(
+  name='B',
+  sources = ['B.scala'],
+  dependencies=[':A'],
+  exports=[':A'],
+  strict_deps=True,
+)
+
+scala_library(
+  name='C',
+  sources = ['C.scala'],
+  dependencies=[':B'],
+  exports=[':B'],
+  strict_deps=True,
+)
+
+scala_library(
+  name='D',
+  sources = ['D.scala'],
+  dependencies=[':C'],
+  strict_deps=True,
+)

testprojects/tests/scala/org/pantsbuild/testproject/exports/C.scala

@@ -0,0 +1,9 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.exports;
+
+class C extends B {
+  def foo_c() {
+  }
+}

testprojects/tests/scala/org/pantsbuild/testproject/exports/D.scala

@@ -0,0 +1,11 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.exports;
+
+class D {
+  def foo_d() {
+    val c = new C();
+    c.foo_c();
+  }
+}

testprojects/tests/scala/org/pantsbuild/testproject/non_exports/A.scala

@@ -0,0 +1,9 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.non_exports;
+
+class A {
+  def foo_a() {
+  }
+}

testprojects/tests/scala/org/pantsbuild/testproject/non_exports/B.scala

@@ -0,0 +1,9 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.non_exports;
+
+class B extends A {
+  def foo_b() {
+  }
+}

testprojects/tests/scala/org/pantsbuild/testproject/non_exports/BUILD

@@ -0,0 +1,18 @@
+scala_library(
+  name='A',
+  sources = ['A.scala'],
+)
+
+scala_library(
+  name='B',
+  sources = ['B.scala'],
+  dependencies=[':A'],
+  strict_deps=True,
+)
+
+scala_library(
+  name='C',
+  sources = ['C.scala'],
+  dependencies=[':B'],
+  strict_deps=True,
+)

testprojects/tests/scala/org/pantsbuild/testproject/non_exports/C.scala

@@ -0,0 +1,11 @@
+// Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.testproject.non_exports;
+
+class C {
+  def foo_c() {
+    val b = new B();
+    b.foo_b();
+  }
+}

tests/python/pants_test/backend/jvm/tasks/jvm_compile/BUILD

@@ -42,6 +42,17 @@ python_tests(
   tags={'integration'},
 )
 
+python_tests(
+  name='dep_exports_integration',
+  sources=['test_dep_exports_integration.py'],
+  dependencies = [
+    'src/python/pants/base:build_environment',
+    'tests/python/pants_test:int-test',
+  ],
+  tags={'integration'},
+  timeout=300,
+)
+
 python_tests(
   name='missing_dependency_finder',
   sources=['test_missing_dependency_finder.py'],

tests/python/pants_test/backend/jvm/tasks/jvm_compile/test_dep_exports_integration.py

@@ -0,0 +1,65 @@
+# coding=utf-8
+# Copyright 2017 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+from __future__ import (absolute_import, division, generators, nested_scopes, print_function,
+                        unicode_literals, with_statement)
+
+import os
+import shutil
+
+from pants.base.build_environment import get_buildroot
+from pants_test.pants_run_integration_test import PantsRunIntegrationTest
+
+
+class DepExportsIntegrationTest(PantsRunIntegrationTest):
+
+  SRC_PREFIX = 'testprojects/tests'
+  SRC_TYPES = ['java', 'scala']
+  SRC_PACKAGE = 'org/pantsbuild/testproject/exports'
+
+  @classmethod
+  def hermetic(cls):
+    return True
+
+  def test_compilation(self):
+    for lang in self.SRC_TYPES:
+      path = os.path.join(self.SRC_PREFIX, lang, self.SRC_PACKAGE)
+      pants_run = self.run_pants(['list', '{}::'.format(path)])
+      self.assert_success(pants_run)
+      target_list = pants_run.stdout_data.strip().split('\n')
+      for target in target_list:
+        pants_run = self.run_pants(['compile', '--compile-scalafmt-skip', target])
+        self.assert_success(pants_run)
+
+  def modify_exports_and_compile(self, target, modify_file):
+    with self.temporary_sourcedir() as tmp_src:
+      src_dir = os.path.relpath(os.path.join(tmp_src, os.path.basename(self.SRC_PACKAGE)), get_buildroot())
+      target_dir, target_name = target.rsplit(':', 1)
+      shutil.copytree(target_dir, src_dir)
+      with self.temporary_workdir() as workdir:
+        cmd = ['compile', '--compile-scalafmt-skip', '{}:{}'.format(src_dir, target_name)]
+        pants_run = self.run_pants_with_workdir(command=cmd, workdir=workdir)
+        self.assert_success(pants_run)
+
+        with open(os.path.join(src_dir, modify_file), 'ab') as fh:
+          fh.write('\n')
+
+        pants_run = self.run_pants_with_workdir(command=cmd, workdir=workdir)
+        self.assert_success(pants_run)
+        self.assertTrue('{}:{}'.format(src_dir, target_name) in pants_run.stdout_data)
+
+  def test_invalidation(self):
+    for lang in self.SRC_TYPES:
+      path = os.path.join(self.SRC_PREFIX, lang, self.SRC_PACKAGE)
+      target = '{}:D'.format(path)
+      self.modify_exports_and_compile(target, 'A.{}'.format(lang))
+      self.modify_exports_and_compile(target, 'B.{}'.format(lang))
+
+  def test_non_exports(self):
+    pants_run = self.run_pants(['compile', '--compile-scalafmt-skip',
+                                'testprojects/tests/scala/org/pantsbuild/testproject/non_exports:C'])
+    self.assert_failure(pants_run)
+    self.assertIn('FAILURE: Compilation failure: Failed jobs: '
+                  'compile(testprojects/tests/scala/org/pantsbuild/testproject/non_exports:C)',
+                  pants_run.stdout_data)

tests/python/pants_test/projects/test_testprojects_integration.py

@@ -57,6 +57,7 @@ def targets(self):
       'testprojects/tests/java/org/pantsbuild/testproject/empty:',
       'testprojects/tests/java/org/pantsbuild/testproject/fail256:fail256',
       'testprojects/tests/python/pants/dummies:failing_target',
+      'testprojects/tests/scala/org/pantsbuild/testproject/non_exports:C',
       # These don't pass without special config.
       'testprojects/tests/java/org/pantsbuild/testproject/depman:new-tests',
       'testprojects/tests/java/org/pantsbuild/testproject/depman:old-tests',