[Caching] Add swift-scan-test to test libSwiftScan APIs

Add a new test tool, that is a very simple driver to call into
libSwiftScan APIs. This enables testing libSwiftScan interfaces
directly, without relying on cross repo testing from swift-driver.

This allows adding new tests for cache replay feature, that has quite
some unique code path from how replay works in swift-frontend.

Author: cachemeifyoucan

include/swift-c/DependencyScan/DependencyScan.h

@@ -25,7 +25,7 @@
 /// SWIFTSCAN_VERSION_MINOR should increase when there are API additions.
 /// SWIFTSCAN_VERSION_MAJOR is intended for "major" source/ABI breaking changes.
 #define SWIFTSCAN_VERSION_MAJOR 0
-#define SWIFTSCAN_VERSION_MINOR 5
+#define SWIFTSCAN_VERSION_MINOR 6
 
 SWIFTSCAN_BEGIN_DECLS
 
@@ -441,6 +441,52 @@ typedef struct swiftscan_cas_options_s *swiftscan_cas_options_t;
 /// ActionCache.
 typedef struct swiftscan_cas_s *swiftscan_cas_t;
 
+/// Opaque container for a cached compilation.
+typedef struct swiftscan_cached_compilation_s *swiftscan_cached_compilation_t;
+
+/// Opaque type for a cache replay instance.
+typedef struct swiftscan_cache_replay_instance_s
+    *swiftscan_cache_replay_instance_t;
+
+/// Opaque type for a cancellation token for async cache operations.
+typedef struct swiftscan_cache_cancellation_token_s
+    *swiftscan_cache_cancellation_token_t;
+
+/// Enum types for output types for cache key computation.
+/// List should contain all the output file types, including supplemententary
+/// outputs, except diagnostics outputs, which are covered by cached diagnostic
+/// entry.
+typedef enum {
+  SWIFTSCAN_OUTPUT_TYPE_OBJECT = 0,
+  SWIFTSCAN_OUTPUT_TYPE_SWIFTMODULE = 1,
+  SWIFTSCAN_OUTPUT_TYPE_SWIFTINTERFACE = 2,
+  SWIFTSCAN_OUTPUT_TYPE_SWIFTPRIVATEINTERFACE = 3,
+  SWIFTSCAN_OUTPUT_TYPE_CLANG_MODULE = 4,
+  SWIFTSCAN_OUTPUT_TYPE_CLANG_PCH = 5,
+  SWIFTSCAN_OUTPUT_TYPE_CLANG_HEADER = 6,
+  SWIFTSCAN_OUTPUT_TYPE_SWIFT_SOURCE_INFO = 7,
+  SWIFTSCAN_OUTPUT_TYPE_SWIFT_MODULE_DOC = 8,
+  SWIFTSCAN_OUTPUT_TYPE_DEPENDENCIES = 9,
+  SWIFTSCAN_OUTPUT_TYPE_SWIFT_DEPS = 10,
+  SWIFTSCAN_OUTPUT_TYPE_MODULE_TRACE = 11,
+  SWIFTSCAN_OUTPUT_TYPE_TBD = 12,
+  SWIFTSCAN_OUTPUT_TYPE_SWIFT_MODULE_SUMMARY = 13,
+  SWIFTSCAN_OUTPUT_TYPE_SWIFT_ABI_DESCRIPTOR = 14,
+  SWIFTSCAN_OUTPUT_TYPE_SWIFT_API_DESCRIPTOR = 15,
+  SWIFTSCAN_OUTPUT_TYPE_CONST_VALUE = 16,
+  SWIFTSCAN_OUTPUT_TYPE_MODULE_SEMANTIC_INFO = 17,
+  SWIFTSCAN_OUTPUT_TYPE_YAML_OPT_RECORD = 18,
+  SWIFTSCAN_OUTPUT_TYPE_BITSTREAM_OPT_RECORD = 19,
+  SWIFTSCAN_OUTPUT_TYPE_CACHED_DIAGNOSTICS = 20
+} swiftscan_output_kind_t;
+
+/// Enum types for cache result lookup or replay.
+typedef enum {
+  SWIFTSCAN_CACHE_RESULT_SUCCESS = 0,
+  SWIFTSCAN_CACHE_RESULT_NOT_FOUND = 1,
+  SWIFTSCAN_CACHE_RESULT_ERROR = 2,
+} swiftscan_cache_result_t;
+
 /// Create a \c CASOptions for creating CAS inside scanner specified.
 SWIFTSCAN_PUBLIC swiftscan_cas_options_t swiftscan_cas_options_create(void);
 
@@ -492,6 +538,129 @@ SWIFTSCAN_PUBLIC swiftscan_string_ref_t
 swiftscan_cache_compute_key(swiftscan_cas_t cas, int argc, const char **argv,
                             const char *input, swiftscan_string_ref_t *error);
 
+/// Query the result of the compilation using the output cache key. \c globally
+/// suggests if the lookup should check remote cache if such operation exists.
+/// Returns the CachedCompilation of the result if found, or nullptr if output
+/// is not found or an error occurs. When an error occurs, the error message is
+/// returned via \c error parameter and its caller needs to free the message
+/// using `swiftscan_string_dispose`. The returned CachedCompilation needs to be
+/// freed via `swiftscan_cached_compilation_dispose`.
+SWIFTSCAN_PUBLIC swiftscan_cached_compilation_t
+swiftscan_cache_query(swiftscan_cas_t cas, const char *key, bool globally,
+                      swiftscan_string_ref_t *error);
+
+/// Async version of `swiftscan_cache_query` where result is returned via
+/// callback. Both cache_result enum and CachedCompilation will be provided to
+/// callback. \c ctx is an opaque value that passed to the callback and \c
+/// swiftscan_cache_cancellation_token_t will return an token that can be used
+/// to cancel the async operation. The token needs to be freed by caller using
+/// `swiftscan_cache_cancellation_token_dispose`.
+SWIFTSCAN_PUBLIC void swiftscan_cache_query_async(
+    swiftscan_cas_t cas, const char *key, bool globally, void *ctx,
+    void (*callback)(void *ctx, swiftscan_cache_result_t,
+                     swiftscan_cached_compilation_t,
+                     swiftscan_string_ref_t error),
+    swiftscan_cache_cancellation_token_t *);
+
+/// Dispose a CachedCompilation.
+SWIFTSCAN_PUBLIC void
+    swiftscan_cached_compilation_dispose(swiftscan_cached_compilation_t);
+
+/// Download and materialized the CASObject referenced by the CASID in the local
+/// CAS if needed from a remote CAS.
+/// If the return value is SWIFTSCAN_CACHE_RESULT_ERROR, the error message is
+/// returned via \c error parameter and its caller needs to free the message
+/// using `swiftscan_string_dispose`.
+SWIFTSCAN_PUBLIC swiftscan_cache_result_t
+swiftscan_cache_load_object(swiftscan_cas_t cas, swiftscan_cached_compilation_t,
+                            swiftscan_string_ref_t *error);
+
+/// Async version of `swiftscan_cache_load_object` where result is returned via
+/// callback. \c ctx is an opaque value that passed to the callback and
+/// \c swiftscan_cache_cancellation_token_t will return an token that can be
+/// used to cancel the async operation. The token needs to be freed by caller
+/// using `swiftscan_cache_cancellation_token_dispose`.
+SWIFTSCAN_PUBLIC void swiftscan_cache_load_object_async(
+    swiftscan_cas_t cas, swiftscan_cached_compilation_t, void *ctx,
+    void (*callback)(void *ctx, swiftscan_cache_result_t,
+                     swiftscan_string_ref_t error),
+    swiftscan_cache_cancellation_token_t *);
+
+/// Check if CachedCompilation is materialized locally and can be accessed
+/// without downloading.
+SWIFTSCAN_PUBLIC bool
+    swiftscan_cache_compilation_is_loaded(swiftscan_cached_compilation_t);
+
+/// Query the number of outputs from a cached compilation. The cached
+/// compilation needs to be loaded, otherwise will return error. The error
+/// message is returned via \c error parameter and its caller needs to free the
+/// message using `swiftscan_string_dispose`.
+SWIFTSCAN_PUBLIC unsigned
+swiftscan_cache_get_num_cached_outputs(swiftscan_cached_compilation_t,
+                                       swiftscan_string_ref_t *error);
+
+/// Query if the kind of otuput exists in a cached compilation. The cached
+/// compilation needs to be loaded, otherwise will return error. The error
+/// message is returned via \c error parameter and its caller needs to free the
+/// message using `swiftscan_string_dispose`.
+SWIFTSCAN_PUBLIC bool
+swiftscan_cache_compilation_has_output_kind(swiftscan_cached_compilation_t,
+                                            swiftscan_output_kind_t,
+                                            swiftscan_string_ref_t *error);
+
+/// Make the cache compilation available globally. \c callback will be called
+/// on completion.
+/// \c swiftscan_cache_cancellation_token_t will return an token that can be
+/// used to cancel the async operation. The token needs to be freed by caller
+/// using `swiftscan_cache_cancellation_token_dispose`.
+SWIFTSCAN_PUBLIC void swiftscan_cache_make_global_async(
+    swiftscan_cas_t cas, const char *key, void *ctx,
+    void (*callback)(void *ctx, swiftscan_string_ref_t error),
+    swiftscan_cache_cancellation_token_t *);
+
+/// Cancel the async cache action that is associated with token.
+SWIFTSCAN_PUBLIC void
+    swiftscan_cache_action_cancel(swiftscan_cache_cancellation_token_t);
+
+/// Dispose the cancellation token.
+SWIFTSCAN_PUBLIC void swiftscan_cache_cancellation_token_dispose(
+    swiftscan_cache_cancellation_token_t);
+
+/// Create a swift cached compilation replay instance with its command-line
+/// invocation. Return nullptr when errors occurs and the error message is
+/// returned via \c error parameter and its caller needs to free the message
+/// using `swiftscan_string_dispose`.
+SWIFTSCAN_PUBLIC swiftscan_cache_replay_instance_t
+swiftscan_cache_create_replay_instance(int argc, const char **argv,
+                                       swiftscan_string_ref_t *error);
+
+/// Dispose swift cached compilation replay instance.
+SWIFTSCAN_PUBLIC void
+    swiftscan_cache_replay_instance_dispose(swiftscan_cache_replay_instance_t);
+
+/// Replay the cached compilation using cached compliation replay instance.
+/// If the return value is SWIFTSCAN_CACHE_RESULT_ERROR, the error message is
+/// returned via \c error parameter and its caller needs to free the message
+/// using `swiftscan_string_dispose`.
+SWIFTSCAN_PUBLIC swiftscan_cache_result_t swiftscan_cache_replay_compilation(
+    swiftscan_cas_t cas, swiftscan_cache_replay_instance_t,
+    swiftscan_cached_compilation_t, swiftscan_string_ref_t *error);
+
+/// Async replay the cached compilation. Callback function will be provided
+/// by the cache replay result, and its stdout, stderr, and any error message.
+/// \c ctx is an opaque value that passed to the callback and
+/// \c swiftscan_cache_cancellation_token_t will return an token that can be
+/// used to cancel the async operation. The token needs to be freed by caller
+/// using `swiftscan_cache_cancellation_token_dispose`.
+SWIFTSCAN_PUBLIC void swiftscan_cache_replay_compilation_async(
+    swiftscan_cas_t cas, swiftscan_cache_replay_instance_t,
+    swiftscan_cached_compilation_t, void *ctx,
+    void (*callback)(void *ctx, swiftscan_cache_result_t,
+                     swiftscan_string_ref_t std_out,
+                     swiftscan_string_ref_t std_err,
+                     swiftscan_string_ref_t error),
+    swiftscan_cache_cancellation_token_t *);
+
 //===----------------------------------------------------------------------===//
 
 SWIFTSCAN_END_DECLS

lib/DriverTool/swift_cache_tool_main.cpp

@@ -50,9 +50,8 @@ enum class SwiftCacheToolAction {
 
 struct OutputEntry {
   std::string InputPath;
-  std::string OutputPath;
-  std::string OutputKind;
   std::string CacheKey;
+  std::vector<std::pair<std::string, std::string>> Outputs;
 };
 
 enum ID {
@@ -285,44 +284,41 @@ int SwiftCacheToolInvocation::printOutputKeys() {
 
   std::vector<OutputEntry> OutputKeys;
   bool hasError = false;
-  auto addOutputKey = [&](StringRef InputPath, file_types::ID OutputKind,
-                          StringRef OutputPath) {
+  auto addFromInputFile = [&](const InputFile &Input) {
+    auto InputPath = Input.getFileName();
     auto OutputKey =
         createCompileJobCacheKeyForOutput(CAS, *BaseKey, InputPath);
     if (!OutputKey) {
-      llvm::errs() << "cannot create cache key for " << OutputPath << ": "
+      llvm::errs() << "cannot create cache key for " << InputPath << ": "
                    << toString(OutputKey.takeError()) << "\n";
       hasError = true;
     }
     OutputKeys.emplace_back(
-        OutputEntry{InputPath.str(), OutputPath.str(),
-                    file_types::getTypeName(OutputKind).str(),
-                    CAS.getID(*OutputKey).toString()});
-  };
-  auto addFromInputFile = [&](const InputFile &Input) {
-    auto InputPath = Input.getFileName();
+        OutputEntry{InputPath, CAS.getID(*OutputKey).toString(), {}});
+    auto &Outputs = OutputKeys.back().Outputs;
     if (!Input.outputFilename().empty())
-      addOutputKey(InputPath,
-                   Invocation.getFrontendOptions()
-                       .InputsAndOutputs.getPrincipalOutputType(),
-                   Input.outputFilename());
+      Outputs.emplace_back(file_types::getTypeName(
+                               Invocation.getFrontendOptions()
+                                   .InputsAndOutputs.getPrincipalOutputType()),
+                           Input.outputFilename());
     Input.getPrimarySpecificPaths()
         .SupplementaryOutputs.forEachSetOutputAndType(
             [&](const std::string &File, file_types::ID ID) {
               // Dont print serialized diagnostics.
               if (file_types::isProducedFromDiagnostics(ID))
                 return;
-
-              addOutputKey(InputPath, ID, File);
+              Outputs.emplace_back(file_types::getTypeName(ID), File);
             });
   };
   llvm::for_each(
       Invocation.getFrontendOptions().InputsAndOutputs.getAllInputs(),
       addFromInputFile);
 
   // Add diagnostics file.
-  addOutputKey("<cached-diagnostics>", file_types::ID::TY_CachedDiagnostics,
-               "<cached-diagnostics>");
+  if (!OutputKeys.empty())
+    OutputKeys.front().Outputs.emplace_back(
+        file_types::getTypeName(file_types::ID::TY_CachedDiagnostics),
+        "<cached-diagnostics>");
 
   if (hasError)
     return 1;
@@ -331,10 +327,16 @@ int SwiftCacheToolInvocation::printOutputKeys() {
   Out.array([&] {
     for (const auto &E : OutputKeys) {
       Out.object([&] {
-        Out.attribute("OutputPath", E.OutputPath);
-        Out.attribute("OutputKind", E.OutputKind);
         Out.attribute("Input", E.InputPath);
         Out.attribute("CacheKey", E.CacheKey);
+        Out.attributeArray("Outputs", [&] {
+          for (const auto &OutEntry : E.Outputs) {
+            Out.object([&] {
+              Out.attribute("Kind", OutEntry.first);
+              Out.attribute("Path", OutEntry.second);
+            });
+          }
+        });
       });
     }
   });

test/CAS/swift-scan-test.swift

@@ -0,0 +1,21 @@
+// RUN: %empty-directory(%t)
+
+// RUN: %target-swift-frontend -cache-compile-job -Rcache-compile-job %s -emit-module -emit-module-path %t/Test.swiftmodule -c -emit-dependencies \
+// RUN:  -module-name Test -o %t/test.o -cas-path %t/cas -allow-unstable-cache-key-for-testing
+
+// RUN: %swift-scan-test -action compute_cache_key -cas-path %t/cas -input %s -- %target-swift-frontend -cache-compile-job -Rcache-compile-job %s \
+// RUN:   -emit-module -emit-module-path %t/Test.swiftmodule -c -emit-dependencies -module-name Test -o %t/test.o -cas-path %t/cas \
+// RUN:   -allow-unstable-cache-key-for-testing > %t/key.casid
+
+// RUN: %swift-scan-test -action cache_query -id @%t/key.casid -cas-path %t/cas | %FileCheck %s --check-prefix=CHECK-QUERY
+
+// RUN: %swift-scan-test -action replay_result -cas-path %t/cas -id @%t/key.casid -- %target-swift-frontend -cache-compile-job -Rcache-compile-job %s \
+// RUN:   -emit-module -emit-module-path %t/Test2.swiftmodule -c -emit-dependencies -module-name Test -o %t/test2.o -cas-path %t/cas \
+// RUN:   -allow-unstable-cache-key-for-testing
+
+// RUN: diff %t/Test.swiftmodule %t/Test2.swiftmodule
+// RUN: diff %t/test.o %t/test.o
+
+// CHECK-QUERY: Cached Compilation for key "llvmcas://{{.*}}" has 4 outputs
+
+func testFunc() {}

test/lit.cfg

@@ -345,6 +345,7 @@ config.benchmark_o = inferSwiftBinary('Benchmark_O')
 config.benchmark_driver = inferSwiftBinary('Benchmark_Driver')
 config.wasm_ld = inferSwiftBinary('wasm-ld')
 config.swift_plugin_server = inferSwiftBinary('swift-plugin-server')
+config.swift_scan_test = inferSwiftBinary('swift-scan-test')
 
 config.swift_utils = make_path(config.swift_src_root, 'utils')
 config.line_directive = make_path(config.swift_utils, 'line-directive')
@@ -636,6 +637,7 @@ config.substitutions.append( ('%llvm-strings', config.llvm_strings) )
 config.substitutions.append( ('%target-ptrauth', run_ptrauth ) )
 config.substitutions.append( ('%swift-path', config.swift) )
 config.substitutions.append( ('%swift-plugin-server', config.swift_plugin_server) )
+config.substitutions.append( ('%swift-scan-test', config.swift_scan_test) )
 config.substitutions.append( ('%validate-json', f"{config.python} -m json.tool") )
 
 # This must come after all substitutions containing "%swift".

tools/CMakeLists.txt

@@ -28,6 +28,7 @@ add_swift_tool_subdirectory(libSwiftScan)
 add_swift_tool_subdirectory(libStaticMirror)
 add_swift_tool_subdirectory(libMockPlugin)
 add_swift_tool_subdirectory(swift-plugin-server)
+add_swift_tool_subdirectory(swift-scan-test)
 
 if(SWIFT_INCLUDE_TESTS OR SWIFT_INCLUDE_TEST_BINARIES)
   add_swift_tool_subdirectory(swift-ide-test)

tools/swift-scan-test/CMakeLists.txt

@@ -0,0 +1,11 @@
+add_swift_host_tool(swift-scan-test
+  swift-scan-test.cpp
+  LLVM_LINK_COMPONENTS support
+  SWIFT_COMPONENT tools
+  THINLTO_LD64_ADD_FLTO_CODEGEN_ONLY
+  DOES_NOT_USE_SWIFT
+)
+
+target_link_libraries(swift-scan-test
+                      PRIVATE
+                      libSwiftScan)