Back down the minimum required java version for running Pants tools t…

…o java 7

The pants 1.2.0rc1 release requried java8 to run tests.  This backs down that requirement to java7 for all the pants tools.  (Square has hadoop dependencies that we still want to test under the Java 7 jvm.)

The change to require java 8 was introduced in:

https://rbcommons.com/s/twitter/r/4127/
https://rbcommons.com/s/twitter/r/4253/

This will also require a subsequent update to re-publish the artifacts and bump the junit-runner verison.

Testing Done:
Passed junit tests locally
Tested the runner locally in Square's java repo

CI running at https://travis-ci.org/pantsbuild/pants/builds/168153814

Bugs closed: 3980

Reviewed at https://rbcommons.com/s/twitter/r/4314/

README.md

@@ -29,4 +29,4 @@ At a minimum, pants requires the following to run properly:
 
 Additionally, if you use the jvm backend to work with java or scala code (installed by default):
 
-* OpenJDK or Oracle JDK version 8 or greater
+* OpenJDK or Oracle JDK version 7 or greater

examples/src/java/org/pantsbuild/example/README.md

@@ -281,8 +281,7 @@ should design your bootclasspath to reference the union of all possible jars
 you might need to pull in from different JVMs (any paths that aren't available
 will simply be ignored by java).
 
-**Note:** Currently, pants is known to work with OpenJDK version 7 or greater,
-and Oracle JDK version 6 or greater.
+**Note:** Currently, pants is known to work with OpenJDK and Oracle JDK version 7 or greater.
 
 
 <a pantsmark="jvm_bundles"></a>

src/docs/install.md

@@ -4,10 +4,11 @@ Installing Pants
 There are a few ways to get a runnable version of pants set up for your workspace. Before
 beginning, make sure your machine fits the requirements. At a minimum, pants requires the following to run properly:
 
-* Linux or Mac OS X
-* Python 2.7.x (the latest stable version of 2.7 is recommended)
-* A C compiler, system headers, Python headers (to compile native Python modules)
-* OpenJDK 7 or greater, Oracle JDK 6 or greater
+* Linux or Mac OS X.
+* Python 2.7.x (the latest stable version of 2.7 is recommended).
+* A C compiler, system headers, Python headers (to compile native Python modules) and the libffi
+  library and headers (to compile and link modules that use CFFI to access native code).
+* OpenJDK or Oracle JDK 7 or greater.
 * Internet access (so that pants can fully bootstrap itself)
 
 After you have pants installed, you'll need to

src/java/com/sun/tools/javac/api/BUILD

@@ -6,6 +6,7 @@ java_library(
   sources=globs('*.java'),
   dependencies=[
   ],
+  platform='java7',
   provides=artifact(
     org='org.pantsbuild',
     name='custom_javactool_for_testing',

src/java/org/pantsbuild/args4j/BUILD

@@ -8,6 +8,7 @@ java_library(
     '3rdparty:guava',
     '3rdparty:jsr305',
   ],
+  platform='java7',
   provides=artifact(
     org='org.pantsbuild',
     name='args4j',

src/java/org/pantsbuild/junit/annotations/BUILD

@@ -10,5 +10,6 @@ java_library(
       Annotations for use with org.pantsbuild#junit-runner that support running tests in parallel.
     """)
   ),
-  sources=globs('*.java')
+  sources=globs('*.java'),
+  platform='java7',
 )

src/java/org/pantsbuild/testing/BUILD

@@ -8,5 +8,6 @@ java_library(
     '3rdparty:guava',
     '3rdparty:guava-testlib',
     '3rdparty:junit'
-  ]
+  ],
+  platform='java7',
 )

src/java/org/pantsbuild/tools/jar/BUILD

@@ -9,6 +9,7 @@ java_library(
     '3rdparty:jsr305',
     'src/java/org/pantsbuild/args4j'
   ],
+  platform='java7',
   provides=artifact(
     org='org.pantsbuild',
     name='jar-tool',
@@ -25,5 +26,6 @@ jvm_binary(
   main='org.pantsbuild.tools.jar.Main',
   dependencies=[
     ':jar',
-  ]
+  ],
+  platform='java7',
 )

src/java/org/pantsbuild/tools/junit/BUILD

@@ -20,7 +20,8 @@ java_library(
     'src/java/org/pantsbuild/junit/annotations',
     'src/java/org/pantsbuild/tools/junit/withretry',
   ],
-  sources=globs('*.java', 'impl/*.java', 'impl/experimental/*.java')
+  sources=globs('*.java', 'impl/*.java', 'impl/experimental/*.java'),
+  platform='java7',
 )
 
 jvm_binary(
@@ -30,6 +31,7 @@ jvm_binary(
   dependencies=[
     ':junit',
   ],
+  platform='java7',
   description="""
 A replacement for org.junit.runner.JUnitCore.main that adds:
   + support for running individual test methods using [classname]#[methodname]

src/java/org/pantsbuild/tools/junit/impl/Spec.java

@@ -19,9 +19,10 @@
 class Spec {
   private final Class<?> clazz;
   private final ImmutableSet<String> methods;
+  private static final ImmutableSet<String> empty = ImmutableSet.of();  // To get around java7 quirk
 
   Spec(Class<?> clazz) {
-    this(clazz, ImmutableSet.of());
+    this(clazz, Spec.empty);
   }
 
   private Spec(Class<?> clazz, ImmutableSet<String> methods) {

src/java/org/pantsbuild/tools/junit/impl/SpecParser.java

@@ -3,10 +3,10 @@
 
 package org.pantsbuild.tools.junit.impl;
 
+import com.google.common.base.Optional;
 import java.lang.reflect.Method;
 import java.util.Collection;
 import java.util.LinkedHashMap;
-import java.util.Optional;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Iterables;
@@ -54,12 +54,13 @@ Collection<Spec> parse() throws SpecException {
         addMethod(specString);
       } else {
         Optional<Spec> spec = getOrCreateSpec(specString, specString);
-        spec.ifPresent(s -> {
+        if (spec.isPresent()) {
+          Spec s = spec.get();
           if (specs.containsKey(s.getSpecClass()) && !s.getMethods().isEmpty()) {
             throw new SpecException(specString,
                 "Request for entire class already requesting individual methods");
           }
-        });
+        }
       }
     }
     return specs.values();
@@ -77,10 +78,13 @@ private Optional<Spec> getOrCreateSpec(String className, String specString) thro
     try {
       Class<?> clazz = getClass().getClassLoader().loadClass(className);
       if (Util.isTestClass(clazz)) {
-        return Optional.of(specs.computeIfAbsent(clazz, Spec::new));
-      } else {
-        return Optional.empty();
+        if (!specs.containsKey(clazz)) {
+          Spec newSpec = new Spec(clazz);
+          specs.put(clazz, newSpec);
+        }
+        return Optional.of(specs.get(clazz));
       }
+      return Optional.absent();
     } catch (ClassNotFoundException | NoClassDefFoundError e) {
       throw new SpecException(specString,
           String.format("Class %s not found in classpath.", className), e);
@@ -110,7 +114,8 @@ private void addMethod(String specString) throws SpecException {
     String methodName = results[1];
 
     Optional<Spec> spec = getOrCreateSpec(className, specString);
-    spec.ifPresent(s -> {
+    if (spec.isPresent()) {
+      Spec s = spec.get();
       for (Method clazzMethod : s.getSpecClass().getMethods()) {
         if (clazzMethod.getName().equals(methodName)) {
           Spec specWithMethod = s.withMethod(methodName);
@@ -121,6 +126,6 @@ private void addMethod(String specString) throws SpecException {
       // TODO(John Sirois): Introduce an Either type to make this function total.
       throw new SpecException(specString,
           String.format("Method %s not found in class %s", methodName, className));
-    });
+    }
   }
 }

src/java/org/pantsbuild/tools/junit/withretry/BUILD

@@ -13,5 +13,6 @@ java_library(
   dependencies=[
     '3rdparty:junit',
   ],
-  sources=globs('*.java')
+  sources=globs('*.java'),
+  platform='java7',
 )

src/java/org/pantsbuild/tools/runner/BUILD

@@ -14,7 +14,8 @@ java_library(
   dependencies=[
     '3rdparty:guava',
   ],
-  sources=globs('*.java')
+  sources=globs('*.java'),
+  platform='java7',
 )
 
 jvm_binary(
@@ -24,6 +25,7 @@ jvm_binary(
   dependencies=[
     ':runner-library',
   ],
+  platform='java7',
   description="""
     A command line tool for fixing problems with custom classloading and synthetic jar.
   """

testprojects/src/java/org/pantsbuild/testproject/targetlevels/unspecified/BUILD

@@ -4,7 +4,7 @@
 jvm_binary(
   main='org.pantsbuild.testproject.targetlevels.unspecified.Unspecified',
   dependencies=[
-    ':java6',
+    ':java7',
     ':lib',
   ],
 )
@@ -13,8 +13,8 @@ java_library(name='lib',
   sources=globs('Unspecified.java'),
 )
 
-java_library(name='java6',
-  sources=globs('Six.java'),
-  platform='java6',
+java_library(name='java7',
+  sources=globs('Seven.java'),
+  platform='java7',
   dependencies=[':lib'],
 )

testprojects/src/java/org/pantsbuild/testproject/targetlevels/unspecified/Six.java → testprojects/src/java/org/pantsbuild/testproject/targetlevels/unspecified/Seven.java

@@ -3,9 +3,9 @@
 
 package org.pantsbuild.testproject.targetlevels.unspecified;
 
-public class Six {
+public class Seven {
     public static void main(String[] args) {
         Unspecified.main(args);
-        System.out.println("Java target level six.");
+        System.out.println("Java target level seven.");
     }
 }

tests/java/org/pantsbuild/tools/junit/impl/SpecParserTest.java

@@ -27,7 +27,7 @@ public class SpecParserTest {
 
   @Test(expected = IllegalArgumentException.class)
   public void testEmptySpecsThrows() {
-    new SpecParser(new ArrayList<>());
+    new SpecParser(new ArrayList<String>());
   }
 
   @Test public void testParserClass() throws Exception {

tests/python/pants_test/backend/jvm/tasks/jvm_compile/java/jvm_platform_integration_mixin.py

@@ -103,11 +103,11 @@ def test_compile_java7on6(self):
   def test_compile_target_coercion(self):
     target_spec = 'testprojects/src/java/org/pantsbuild/testproject/targetlevels/unspecified'
     self.assert_class_versions({
-      'org/pantsbuild/testproject/targetlevels/unspecified/Unspecified.class': '1.7',
-      'org/pantsbuild/testproject/targetlevels/unspecified/Six.class': '1.6',
+      'org/pantsbuild/testproject/targetlevels/unspecified/Unspecified.class': '1.8',
+      'org/pantsbuild/testproject/targetlevels/unspecified/Seven.class': '1.7',
     }, self._get_compiled_class_versions(target_spec, more_args=[
       '--jvm-platform-validate-check=warn',
-      '--jvm-platform-default-platform=java7',
+      '--jvm-platform-default-platform=java8',
     ]))
 
   def _test_compile(self, target_level, class_name, source_contents, platform_args=None):

tests/python/pants_test/backend/project_info/tasks/test_idea_integration.py

@@ -404,7 +404,7 @@ def test_all_targets(self):
       # they explicitly include jersey.jersey's source jar.
       '--exclude-target-regexp=testprojects/3rdparty/managed:jersey.jersey.sources',
       '--exclude-target-regexp=testprojects/3rdparty/managed:example-dependee',
-      '--jvm-platform-default-platform=java6'
+      '--jvm-platform-default-platform=java7'
     ])
 
   def test_ivy_classifiers(self):

tests/python/pants_test/projects/test_testprojects_integration.py

@@ -83,7 +83,7 @@ def test_testprojects(self):
                           timeout_targets + deliberately_conflicting_targets)
     exclude_opts = map(lambda target: '--exclude-target-regexp={}'.format(target),
                        targets_to_exclude)
-    pants_run = self.pants_test(['testprojects::', '--jvm-platform-default-platform=java6'] + exclude_opts)
+    pants_run = self.pants_test(['testprojects::', '--jvm-platform-default-platform=java7'] + exclude_opts)
     self.assert_success(pants_run)
 
   # This is a special case that we split into 2 tests instead of using ensure_engine.