Provide jar_snapshot for classpath in kotlincd

Summary:
## Context
To enable Kotlin Incremental Compilation for a target we need to provide a snapshot of all the `.jar` files in its classpath.
See more context in this [doc](https://docs.google.com/document/d/1EpyHaCcOHxGgFWw59vK2HZgcJERReOp6_j-8bCWkIN0/edit?usp=sharing)

## Steps
1 . Create a utility to generate snapshot  for given `.jar`
2 . Provide jar_snapshot in JavaClasspathEntry
➜ 3 . Pass jar_snapshot for all `.jar` files in the classpath to KotlinCD
4 . In KotlinCD, deserialize and maintain a map of classpath to snapshot
5 . Provide classpath->snapshot map to incremental compilation

## This Diff
When building a target incrementally, pass jar_snapshot for all `.jar` files in the classpath to KotlinCD

Reviewed By: IanChilds

Differential Revision: D62533759

fbshipit-source-id: bb17d15db9e5df069c53d79ab7c5bee20df49771

jvm/cd_jar_creator_util.bzl

@@ -288,16 +288,20 @@ def encode_base_jar_command(
         manifest_file: Artifact | None,
         extra_arguments: cmd_args,
         source_only_abi_compiling_deps: list[JavaClasspathEntry],
-        track_class_usage: bool) -> struct:
+        track_class_usage: bool,
+        is_incremental: bool = False) -> struct:
     library_jar_params = encode_jar_params(remove_classes, output_paths, manifest_file)
     qualified_name = get_qualified_name(label, target_type)
     if target_type == TargetType("source_only_abi"):
         compiling_classpath = classpath_jars_tag.tag_artifacts([dep.abi for dep in source_only_abi_compiling_deps])
+        compiling_classpath_snapshot = {}
     else:
         expect(len(source_only_abi_compiling_deps) == 0)
+        compiling_deps_list = filter(None, list(compiling_deps_tset.traverse())) if compiling_deps_tset else []
         compiling_classpath = classpath_jars_tag.tag_artifacts(
-            compiling_deps_tset.project_as_json("javacd_json") if compiling_deps_tset else None,
+            [dep.abi for dep in compiling_deps_list],
         )
+        compiling_classpath_snapshot = {dep.abi: dep.abi_jar_snapshot for dep in compiling_deps_list if dep.abi_jar_snapshot} if is_incremental else {}
 
     build_target_value = struct(
         fullyQualifiedName = qualified_name,
@@ -328,6 +332,7 @@ def encode_base_jar_command(
     return struct(
         outputPathsValue = encode_output_paths(label, output_paths, target_type),
         compileTimeClasspathPaths = compiling_classpath,
+        compileTimeClasspathSnapshotPaths = compiling_classpath_snapshot,
         javaSrcs = srcs,
         # TODO(cjhopman): populate jar infos. I think these are only used for unused dependencies (and appear to be broken in buck1 w/javacd anyway).
         fullJarInfos = [],

kotlin/kotlincd_jar_creator.bzl

@@ -105,6 +105,9 @@ def create_jar_artifact_kotlincd(
         jvm_abi_gen = None
         should_use_jvm_abi_gen = False
 
+    should_kotlinc_run_incrementally = kotlin_toolchain.enable_incremental_compilation and incremental
+    incremental_state_dir = declare_prefixed_output(actions, actions_identifier, "incremental_state", dir = True) if should_kotlinc_run_incrementally else None
+
     def encode_kotlin_extra_params(kotlin_compiler_plugins, incremental_state_dir = None):
         kosabiPluginOptionsMap = {}
         if kotlin_toolchain.kosabi_stubs_gen_plugin != None:
@@ -147,7 +150,7 @@ def create_jar_artifact_kotlincd(
             shouldRemoveKotlinCompilerFromClassPath = True,
             depTrackerPlugin = kotlin_toolchain.track_class_usage_plugin,
             shouldKotlincRunViaBuildToolsApi = kotlin_toolchain.kotlinc_run_via_build_tools_api,
-            shouldKotlincRunIncrementally = incremental_state_dir != None,
+            shouldKotlincRunIncrementally = should_kotlinc_run_incrementally,
             incrementalStateDir = incremental_state_dir.as_output() if incremental_state_dir else None,
             shouldUseStandaloneKosabi = kotlin_toolchain.kosabi_standalone,
         )
@@ -183,6 +186,7 @@ def create_jar_artifact_kotlincd(
             extra_arguments = cmd_args(extra_arguments),
             source_only_abi_compiling_deps = [],
             track_class_usage = track_class_usage,
+            is_incremental = should_kotlinc_run_incrementally,
         )
 
         return struct(
@@ -359,10 +363,6 @@ def create_jar_artifact_kotlincd(
         )
 
     library_classpath_jars_tag = actions.artifact_tag()
-    incremental_state_dir = None
-    shouldKotlincRunIncrementally = kotlin_toolchain.enable_incremental_compilation and incremental
-    if shouldKotlincRunIncrementally:
-        incremental_state_dir = declare_prefixed_output(actions, actions_identifier, "incremental_state", dir = True)
     command = encode_library_command(output_paths, path_to_class_hashes_out, library_classpath_jars_tag, incremental_state_dir)
     define_kotlincd_action(
         category_prefix = "",