Make JVM sources runnable (#17847)

This adds `./pants run`/`experimental_run_in_sandbox` support for more JVM targets without needing to explicitly declare a `deploy_jar`. It does that by adapting the existing `jvm_artifact` rule, which was already fairly generic thanks to the use of `ClasspathEntryRequest` rules.

The rules will attempt to automatically find a `main` method through either a JAR manifest (as before for `jvm_artifact`) or by directly inspecting the contents of the classpath entry JAR returned from compilation. This also permits explicitly declaring a `main` method in case the other approaches are inconclusive.

src/python/pants/backend/java/target_types.py

@@ -22,8 +22,10 @@
     JunitTestTimeoutField,
     JvmDependenciesField,
     JvmJdkField,
+    JvmMainClassNameField,
     JvmProvidesTypesField,
     JvmResolveField,
+    JvmRunnableSourceFieldSet,
 )
 
 
@@ -36,7 +38,7 @@ class JavaGeneratorSourcesField(MultipleSourcesField):
 
 
 @dataclass(frozen=True)
-class JavaFieldSet(FieldSet):
+class JavaFieldSet(JvmRunnableSourceFieldSet):
     required_fields = (JavaSourceField,)
 
     sources: JavaSourceField
@@ -111,6 +113,7 @@ class JavaSourceTarget(Target):
         JvmDependenciesField,
         JavaSourceField,
         JvmResolveField,
+        JvmMainClassNameField,
         JvmProvidesTypesField,
         JvmJdkField,
     )
@@ -136,6 +139,7 @@ class JavaSourcesGeneratorTarget(TargetFilesGenerator):
         JvmDependenciesField,
         JvmResolveField,
         JvmJdkField,
+        JvmMainClassNameField,
         JvmProvidesTypesField,
     )
     help = "Generate a `java_source` target for each file in the `sources` field."
@@ -145,4 +149,5 @@ def rules():
     return [
         *collect_rules(),
         *jvm_target_types.rules(),
+        *JavaFieldSet.jvm_rules(),
     ]

src/python/pants/backend/kotlin/target_types.py

@@ -5,7 +5,6 @@
 
 from dataclasses import dataclass
 
-from pants.engine.rules import collect_rules
 from pants.engine.target import (
     COMMON_TARGET_FIELDS,
     AsyncFieldMixin,
@@ -24,8 +23,10 @@
     JunitTestSourceField,
     JunitTestTimeoutField,
     JvmJdkField,
+    JvmMainClassNameField,
     JvmProvidesTypesField,
     JvmResolveField,
+    JvmRunnableSourceFieldSet,
 )
 from pants.util.strutil import softwrap
 
@@ -56,7 +57,7 @@ class KotlincConsumedPluginIdsField(StringSequenceField):
 
 
 @dataclass(frozen=True)
-class KotlinFieldSet(FieldSet):
+class KotlinFieldSet(JvmRunnableSourceFieldSet):
     required_fields = (KotlinSourceField,)
 
     sources: KotlinSourceField
@@ -88,6 +89,7 @@ class KotlinSourceTarget(Target):
         JvmResolveField,
         JvmProvidesTypesField,
         JvmJdkField,
+        JvmMainClassNameField,
     )
     help = "A single Kotlin source file containing application or library code."
 
@@ -113,6 +115,7 @@ class KotlinSourcesGeneratorTarget(TargetFilesGenerator):
         JvmResolveField,
         JvmJdkField,
         JvmProvidesTypesField,
+        JvmMainClassNameField,
     )
     help = "Generate a `kotlin_source` target for each file in the `sources` field."
 
@@ -232,4 +235,6 @@ class KotlincPluginTarget(Target):
 
 
 def rules():
-    return collect_rules()
+    return [
+        *KotlinFieldSet.jvm_rules(),
+    ]

src/python/pants/backend/scala/compile/scalac.py

@@ -44,6 +44,7 @@
 from pants.jvm.resolve.coursier_fetch import ToolClasspath, ToolClasspathRequest
 from pants.jvm.strip_jar.strip_jar import StripJarRequest
 from pants.jvm.subsystems import JvmSubsystem
+from pants.jvm.target_types import NO_MAIN_CLASS
 from pants.util.logging import LogLevel
 
 logger = logging.getLogger(__name__)
@@ -188,7 +189,7 @@ async def compile_scala_source(
                 # NB: We set a non-existent main-class so that using `-d` produces a `jar` manifest
                 # with stable content.
                 "-Xmain-class",
-                "no.main.class",
+                NO_MAIN_CLASS,
                 "-d",
                 output_file,
                 *sorted(

src/python/pants/backend/scala/target_types.py

@@ -32,8 +32,10 @@
     JunitTestSourceField,
     JunitTestTimeoutField,
     JvmJdkField,
+    JvmMainClassNameField,
     JvmProvidesTypesField,
     JvmResolveField,
+    JvmRunnableSourceFieldSet,
 )
 from pants.util.strutil import softwrap
 
@@ -82,7 +84,7 @@ class ScalaConsumedPluginNamesField(StringSequenceField):
 
 
 @dataclass(frozen=True)
-class ScalaFieldSet(FieldSet):
+class ScalaFieldSet(JvmRunnableSourceFieldSet):
     required_fields = (ScalaSourceField,)
 
     sources: ScalaSourceField
@@ -258,6 +260,7 @@ class ScalaSourceTarget(Target):
         JvmResolveField,
         JvmProvidesTypesField,
         JvmJdkField,
+        JvmMainClassNameField,
     )
     help = "A single Scala source file containing application or library code."
 
@@ -305,6 +308,7 @@ class ScalaSourcesGeneratorTarget(TargetFilesGenerator):
         ScalaConsumedPluginNamesField,
         JvmResolveField,
         JvmJdkField,
+        JvmMainClassNameField,
         JvmProvidesTypesField,
     )
     settings_request_cls = ScalaSettingsRequest
@@ -359,5 +363,6 @@ def rules():
     return (
         *collect_rules(),
         *jvm_target_types.rules(),
+        *ScalaFieldSet.jvm_rules(),
         UnionRule(TargetFilesGeneratorSettingsRequest, ScalaSettingsRequest),
     )

src/python/pants/core/goals/run.py

@@ -9,7 +9,17 @@
 from dataclasses import dataclass
 from enum import Enum
 from itertools import filterfalse, tee
-from typing import Callable, ClassVar, Iterable, Mapping, NamedTuple, Optional, Tuple, TypeVar
+from typing import (
+    Callable,
+    ClassVar,
+    Iterable,
+    Mapping,
+    NamedTuple,
+    Optional,
+    Tuple,
+    TypeVar,
+    Union,
+)
 
 from typing_extensions import final
 
@@ -27,6 +37,7 @@
 from pants.engine.rules import (
     Effect,
     Get,
+    Rule,
     _uncacheable_rule,
     collect_rules,
     goal_rule,
@@ -91,7 +102,7 @@ class RunFieldSet(FieldSet, metaclass=ABCMeta):
 
     @final
     @classmethod
-    def rules(cls) -> Iterable:
+    def rules(cls) -> Iterable[Union[Rule, UnionRule]]:
         yield UnionRule(RunFieldSet, cls)
         if not cls.supports_debug_adapter:
             yield from _unsupported_debug_adapter_rules(cls)

src/python/pants/jvm/jvm_common.py

@@ -1,6 +1,6 @@
 # Copyright 2022 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
-from pants.jvm import classpath, jdk_rules, resources, run
+from pants.jvm import classpath, jdk_rules, resources, run, run_deploy_jar
 from pants.jvm import util_rules as jvm_util_rules
 from pants.jvm.dependency_inference import symbol_mapper
 from pants.jvm.goals import lockfile
@@ -39,6 +39,7 @@ def rules():
         *jdk_rules.rules(),
         *jvm_tool.rules(),
         *run.rules(),
+        *run_deploy_jar.rules(),
         *war_rules(),
     ]
 

src/python/pants/jvm/package/deploy_jar.py

@@ -50,6 +50,7 @@ class DeployJarFieldSet(PackageFieldSet, RunFieldSet):
         JvmMainClassNameField,
         JvmJdkField,
         Dependencies,
+        OutputPathField,
     )
     run_in_sandbox_behavior = RunInSandboxBehavior.RUN_REQUEST_HERMETIC