[jvm-compile] Copy compile classpath into runtime classpath even if a…

…lready defined

In pantsbuild#4309, the problem was caused by jvm_compile assuming it is always first in the compile order. This ensures the compile_classpath is mixed into the runtime classpath even if it has already been initialized.

Another approach would be to move the NodeBuild task to later in the compile goal, and make it an error for jvm_compile to receive a runtime classpath.

src/python/pants/backend/jvm/tasks/classpath_products.py

@@ -305,6 +305,15 @@ def get_internal_classpath_entries_for_targets(self, targets, respect_excludes=T
     return [(conf, cp_entry) for conf, cp_entry in classpath_tuples
             if ClasspathEntry.is_internal_classpath_entry(cp_entry)]
 
+  def update(self, other):
+    """Adds the contents of other to this ClasspathProducts."""
+    if self._pants_workdir != other._pants_workdir:
+      raise ValueError('Other ClasspathProducts from a different pants workdir {}'.format(other._pants_workdir))
+    for target, products in other._classpaths._products_by_target.items():
+      self._classpaths.add_for_target(target, products)
+    for target, products in other._excludes._products_by_target.items():
+      self._excludes.add_for_target(target, products)
+
   def _filter_by_excludes(self, classpath_target_tuples, root_targets):
     # Excludes are always applied transitively, so regardless of whether a transitive
     # set of targets was included here, their closure must be included.

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

@@ -440,8 +440,7 @@ def execute(self):
       return
 
     # Clone the compile_classpath to the runtime_classpath.
-    compile_classpath = self.context.products.get_data('compile_classpath')
-    classpath_product = self.context.products.get_data('runtime_classpath', compile_classpath.copy)
+    classpath_product = self.create_runtime_classpath()
 
     def classpath_for_context(context):
       if self.get_options().use_classpath_jars:
@@ -484,6 +483,16 @@ def classpath_for_context(context):
             classpath_product.remove_for_target(cc.target, [(conf, cc.classes_dir)])
             classpath_product.add_for_target(cc.target, [(conf, cc.jar_file)])
 
+  def create_runtime_classpath(self):
+    compile_classpath = self.context.products.get_data('compile_classpath')
+    classpath_product = self.context.products.get_data('runtime_classpath')
+    if not classpath_product:
+      classpath_product = self.context.products.get_data('runtime_classpath', compile_classpath.copy)
+    else:
+      classpath_product.update(compile_classpath)
+
+    return classpath_product
+
   def do_compile(self,
                  invalidation_check,
                  compile_contexts,

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

@@ -13,6 +13,17 @@ python_tests(
   ],
 )
 
+python_tests(
+  name = 'jvm_compile',
+  sources = ['test_jvm_compile.py'],
+  dependencies = [
+    'src/python/pants/backend/jvm/tasks:classpath_products',
+    'src/python/pants/backend/jvm/tasks/jvm_compile',
+    'tests/python/pants_test/tasks:task_test_base',
+  ],
+)
+
+
 python_library(
   name='base_compile_integration_test',
   sources=['base_compile_integration_test.py'],

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

@@ -0,0 +1,49 @@
+# 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
+
+from pants.backend.jvm.targets.java_library import JavaLibrary
+from pants.backend.jvm.tasks.classpath_products import ClasspathProducts
+from pants.backend.jvm.tasks.jvm_compile.jvm_compile import JvmCompile
+from pants_test.tasks.task_test_base import TaskTestBase
+
+
+class DummyJvmCompile(JvmCompile):
+
+  def create_analysis_tools(self):
+    return None
+
+
+class JvmCompileTest(TaskTestBase):
+  DEFAULT_CONF = 'default'
+
+  @classmethod
+  def task_type(cls):
+    return DummyJvmCompile
+
+  def test_if_runtime_classpath_exists(self):
+    target = self.make_target(
+      'java/classpath:java_lib',
+      target_type=JavaLibrary,
+      sources=['com/foo/Bar.java'],
+    )
+
+    context = self.context(target_roots=[target])
+    compile_classpath = context.products.get_data('compile_classpath', ClasspathProducts.init_func(self.pants_workdir))
+
+    compile_entry = os.path.join(self.pants_workdir, 'compile-entry')
+    pre_init_runtime_entry = os.path.join(self.pants_workdir, 'pre-inited-runtime-entry')
+    compile_classpath.add_for_targets([target], [('default', compile_entry)])
+    runtime_classpath = context.products.get_data('runtime_classpath', ClasspathProducts.init_func(self.pants_workdir))
+
+    runtime_classpath.add_for_targets([target], [('default', pre_init_runtime_entry)])
+
+    task = self.create_task(context)
+    resulting_classpath = task.create_runtime_classpath()
+    self.assertEqual([('default', pre_init_runtime_entry), ('default', compile_entry)],
+      resulting_classpath.get_for_target(target))