Add index-while-building support (back) to the Swift build rules

doc/api.md

@@ -122,28 +122,39 @@ Compiles a Swift module.
 
 **RETURNS**
 
-A tuple containing three elements:
-
-  1.  A Swift module context (as returned by `swift_common.create_module`)
-      that contains the Swift (and potentially C/Objective-C) compilation
-      prerequisites of the compiled module. This should typically be
-      propagated by a `SwiftInfo` provider of the calling rule, and the
-      `CcCompilationContext` inside the Clang module substructure should
-      be propagated by the `CcInfo` provider of the calling rule.
-  2.  A `CcCompilationOutputs` object (as returned by
-      `cc_common.create_compilation_outputs`) that contains the compiled
-      object files.
-  3.  A struct containing:
+A `struct` with the following fields:
+
+  *   `module_context`: A Swift module context (as returned by
+      `swift_common.create_module`) that contains the Swift (and
+      potentially C/Objective-C) compilation prerequisites of the compiled
+      module. This should typically be propagated by a `SwiftInfo`
+      provider of the calling rule, and the `CcCompilationContext` inside
+      the Clang module substructure should be propagated by the `CcInfo`
+      provider of the calling rule.
+
+  *   `compilation_outputs`: A `CcCompilationOutputs` object (as returned
+      by `cc_common.create_compilation_outputs`) that contains the
+      compiled object files.
+
+  *   `supplemental_outputs`: A `struct` representing supplemental,
+      optional outputs. Its fields are:
+
       *   `ast_files`: A list of `File`s output from the `DUMP_AST`
           action.
-      *   `indexstore`: A `File` representing the directory that contains
-          the index store data generated by the compiler if the
-          `"swift.index_while_building"` feature is enabled, otherwise
-          this will be `None`.
+
       *   `const_values_files`: A list of `File`s that contains JSON
           representations of constant values extracted from the source
           files, if requested via a direct dependency.
 
+      *   `indexstore_directory`: A directory-type `File` that represents
+          the indexstore output files created when the feature
+          `swift.index_while_building` is enabled.
+
+      *   `macro_expansion_directory`: A directory-type `File` that
+          represents the location where macro expansion files were written
+          (only in debug/fastbuild and only when the toolchain supports
+          macros).
+
 
 <a id="swift_common.compile_module_interface"></a>
 

proto/swift_proto_utils.bzl

@@ -267,7 +267,7 @@ def compile_swift_protos_for_target(
 
     # Compile the generated Swift source files as a module:
     include_dev_srch_paths = include_developer_search_paths(attr)
-    module_context, cc_compilation_outputs, supplemental_outputs = swift_common.compile(
+    compile_result = swift_common.compile(
         actions = ctx.actions,
         cc_infos = get_providers(compiler_deps, CcInfo),
         copts = ["-parse-as-library"],
@@ -283,11 +283,15 @@ def compile_swift_protos_for_target(
         workspace_name = ctx.workspace_name,
     )
 
+    module_context = compile_result.module_context
+    compilation_outputs = compile_result.compilation_outputs
+    supplemental_outputs = compile_result.supplemental_outputs
+
     # Create the linking context from the compilation outputs:
     linking_context, linking_output = (
         swift_common.create_linking_context_from_compilation_outputs(
             actions = ctx.actions,
-            compilation_outputs = cc_compilation_outputs,
+            compilation_outputs = compilation_outputs,
             feature_configuration = feature_configuration,
             include_dev_srch_paths = include_dev_srch_paths,
             label = target_label,

swift/internal/compiling.bzl

@@ -438,27 +438,38 @@ def compile(
              outputs.
 
     Returns:
-        A tuple containing three elements:
-
-        1.  A Swift module context (as returned by `swift_common.create_module`)
-            that contains the Swift (and potentially C/Objective-C) compilation
-            prerequisites of the compiled module. This should typically be
-            propagated by a `SwiftInfo` provider of the calling rule, and the
-            `CcCompilationContext` inside the Clang module substructure should
-            be propagated by the `CcInfo` provider of the calling rule.
-        2.  A `CcCompilationOutputs` object (as returned by
-            `cc_common.create_compilation_outputs`) that contains the compiled
-            object files.
-        3.  A struct containing:
+        A `struct` with the following fields:
+
+        *   `module_context`: A Swift module context (as returned by
+            `swift_common.create_module`) that contains the Swift (and
+            potentially C/Objective-C) compilation prerequisites of the compiled
+            module. This should typically be propagated by a `SwiftInfo`
+            provider of the calling rule, and the `CcCompilationContext` inside
+            the Clang module substructure should be propagated by the `CcInfo`
+            provider of the calling rule.
+
+        *   `compilation_outputs`: A `CcCompilationOutputs` object (as returned
+            by `cc_common.create_compilation_outputs`) that contains the
+            compiled object files.
+
+        *   `supplemental_outputs`: A `struct` representing supplemental,
+            optional outputs. Its fields are:
+
             *   `ast_files`: A list of `File`s output from the `DUMP_AST`
                 action.
-            *   `indexstore`: A `File` representing the directory that contains
-                the index store data generated by the compiler if the
-                `"swift.index_while_building"` feature is enabled, otherwise
-                this will be `None`.
+
             *   `const_values_files`: A list of `File`s that contains JSON
                 representations of constant values extracted from the source
                 files, if requested via a direct dependency.
+
+            *   `indexstore_directory`: A directory-type `File` that represents
+                the indexstore output files created when the feature
+                `swift.index_while_building` is enabled.
+
+            *   `macro_expansion_directory`: A directory-type `File` that
+                represents the location where macro expansion files were written
+                (only in debug/fastbuild and only when the toolchain supports
+                macros).
     """
 
     # Collect the `SwiftInfo` providers that represent the dependencies of the
@@ -810,20 +821,22 @@ to use swift_common.compile(include_dev_srch_paths = ...) instead.\
         ),
     )
 
-    cc_compilation_outputs = cc_common.create_compilation_outputs(
+    compilation_outputs = cc_common.create_compilation_outputs(
         objects = depset(compile_outputs.object_files),
         pic_objects = depset(compile_outputs.object_files),
     )
 
-    other_compilation_outputs = struct(
-        ast_files = compile_outputs.ast_files,
-        indexstore = compile_outputs.indexstore_directory,
-        macro_expansion_directory = compile_outputs.macro_expansion_directory,
-        const_values_files = compile_outputs.const_values_files,
+    return struct(
+        module_context = module_context,
+        compilation_outputs = compilation_outputs,
+        supplemental_outputs = struct(
+            ast_files = compile_outputs.ast_files,
+            const_values_files = compile_outputs.const_values_files,
+            indexstore_directory = compile_outputs.indexstore_directory,
+            macro_expansion_directory = compile_outputs.macro_expansion_directory,
+        ),
     )
 
-    return module_context, cc_compilation_outputs, other_compilation_outputs
-
 def precompile_clang_module(
         *,
         actions,

swift/internal/feature_names.bzl

@@ -65,6 +65,16 @@ SWIFT_FEATURE_FILE_PREFIX_MAP = "swift.file_prefix_map"
 # graph.
 SWIFT_FEATURE_EMIT_C_MODULE = "swift.emit_c_module"
 
+# If enabled, the compilation action for a target will produce an index store.
+# https://docs.google.com/document/d/1cH2sTpgSnJZCkZtJl1aY-rzy4uGPcrI-6RrUpdATO2Q/
+SWIFT_FEATURE_INDEX_WHILE_BUILDING = "swift.index_while_building"
+
+# If enabled the compilation action will not produce indexes for system modules.
+SWIFT_FEATURE_DISABLE_SYSTEM_INDEX = "swift.disable_system_index"
+
+# Index while building - using a global index store cache
+SWIFT_FEATURE_USE_GLOBAL_INDEX_STORE = "swift.use_global_index_store"
+
 # If enabled, when compiling an explicit C or Objectve-C module, every header
 # included by the module being compiled must belong to one of the modules listed
 # in its dependencies. This is ignored for system modules.
@@ -103,16 +113,6 @@ SWIFT_FEATURE_FULL_DEBUG_INFO = "swift.full_debug_info"
 # Use CodeView debug information, which enables generation of PDBs for debugging.
 SWIFT_FEATURE_CODEVIEW_DEBUG_INFO = "swift.codeview_debug_info"
 
-# If enabled, the compilation action for a target will produce an index store.
-# https://docs.google.com/document/d/1cH2sTpgSnJZCkZtJl1aY-rzy4uGPcrI-6RrUpdATO2Q/
-SWIFT_FEATURE_INDEX_WHILE_BUILDING = "swift.index_while_building"
-
-# If enabled the compilation action will not produce indexes for system modules.
-SWIFT_FEATURE_DISABLE_SYSTEM_INDEX = "swift.disable_system_index"
-
-# Index while building - using a global index store cache
-SWIFT_FEATURE_USE_GLOBAL_INDEX_STORE = "swift.use_global_index_store"
-
 # If enabled, compilation actions and module map generation will assume that the
 # header paths in module maps are relative to the current working directory
 # (i.e., the workspace root); if disabled, header paths in module maps are

swift/internal/output_groups.bzl

@@ -41,8 +41,8 @@ def supplemental_compilation_output_groups(*supplemental_outputs):
             ast_files.extend(outputs.ast_files)
         if outputs.const_values_files:
             const_values_files.extend(outputs.const_values_files)
-        if outputs.indexstore:
-            indexstore_files.append(outputs.indexstore)
+        if outputs.indexstore_directory:
+            indexstore_files.append(outputs.indexstore_directory)
         if outputs.macro_expansion_directory:
             macro_expansions_files.append(outputs.macro_expansion_directory)
 

swift/swift_binary.bzl

@@ -69,9 +69,9 @@ def _swift_binary_impl(ctx):
     )
 
     srcs = ctx.files.srcs
+    output_groups = {}
     module_contexts = []
     additional_linking_contexts = []
-    all_supplemental_outputs = []
 
     # If the binary has sources, compile those first and collect the outputs to
     # be passed to the linker.
@@ -82,7 +82,7 @@ def _swift_binary_impl(ctx):
 
         include_dev_srch_paths = include_developer_search_paths(ctx.attr)
 
-        module_context, cc_compilation_outputs, supplemental_outputs = swift_common.compile(
+        compile_result = swift_common.compile(
             actions = ctx.actions,
             additional_inputs = ctx.files.swiftc_inputs,
             cc_infos = get_providers(ctx.attr.deps, CcInfo),
@@ -104,16 +104,21 @@ def _swift_binary_impl(ctx):
             target_name = ctx.label.name,
             workspace_name = ctx.workspace_name,
         )
+        module_context = compile_result.module_context
         module_contexts.append(module_context)
-        all_supplemental_outputs.append(supplemental_outputs)
+        compilation_outputs = compile_result.compilation_outputs
+        supplemental_outputs = compile_result.supplemental_outputs
+        output_groups = supplemental_compilation_output_groups(
+            supplemental_outputs,
+        )
 
         # Unlike `upstream`, we create a linking_context in order to support
         # `autolink-extract`. See `a1395155c6a27d76aab5e1a93455259a0ac10b2f` and
         # `93219a3b21390f212f5fd013e8db3654fd09814c`.
         linking_context, _ = swift_common.create_linking_context_from_compilation_outputs(
             actions = ctx.actions,
             alwayslink = True,
-            compilation_outputs = cc_compilation_outputs,
+            compilation_outputs = compilation_outputs,
             feature_configuration = feature_configuration,
             include_dev_srch_paths = include_dev_srch_paths,
             label = ctx.label,
@@ -126,8 +131,6 @@ def _swift_binary_impl(ctx):
             swift_toolchain = swift_toolchain,
         )
         additional_linking_contexts.append(linking_context)
-    else:
-        cc_compilation_outputs = cc_common.create_compilation_outputs()
 
     additional_linking_contexts.append(malloc_linking_context(ctx))
 
@@ -172,11 +175,7 @@ def _swift_binary_impl(ctx):
                 files = ctx.files.data,
             ),
         ),
-        OutputGroupInfo(
-            **supplemental_compilation_output_groups(
-                *all_supplemental_outputs
-            )
-        ),
+        OutputGroupInfo(**output_groups),
         swift_common.create_swift_info(
             modules = [
                 swift_common.create_module(

swift/swift_compiler_plugin.bzl

@@ -70,7 +70,7 @@ def _swift_compiler_plugin_impl(ctx):
         module_name = derive_swift_module_name(ctx.label)
     entry_point_function_name = "{}_main".format(module_name)
 
-    module_context, cc_compilation_outputs, supplemental_outputs = swift_common.compile(
+    compile_result = swift_common.compile(
         actions = ctx.actions,
         additional_inputs = ctx.files.swiftc_inputs,
         cc_infos = get_providers(deps, CcInfo),
@@ -103,9 +103,9 @@ def _swift_compiler_plugin_impl(ctx):
         target_name = ctx.label.name,
         workspace_name = ctx.workspace_name,
     )
-    output_groups = supplemental_compilation_output_groups(
-        supplemental_outputs,
-    )
+    module_context = compile_result.module_context
+    compilation_outputs = compile_result.compilation_outputs
+    supplemental_outputs = compile_result.supplemental_outputs
 
     cc_feature_configuration = swift_common.cc_feature_configuration(
         feature_configuration = feature_configuration,
@@ -116,7 +116,7 @@ def _swift_compiler_plugin_impl(ctx):
         additional_inputs = ctx.files.swiftc_inputs,
         additional_linking_contexts = [malloc_linking_context(ctx)],
         cc_feature_configuration = cc_feature_configuration,
-        compilation_outputs = cc_compilation_outputs,
+        compilation_outputs = compilation_outputs,
         deps = deps,
         name = ctx.label.name,
         output_type = "executable",
@@ -141,7 +141,7 @@ def _swift_compiler_plugin_impl(ctx):
             actions = ctx.actions,
             additional_inputs = ctx.files.swiftc_inputs,
             alwayslink = True,
-            compilation_outputs = cc_compilation_outputs,
+            compilation_outputs = compilation_outputs,
             feature_configuration = feature_configuration,
             label = ctx.label,
             include_dev_srch_paths = ctx.attr.testonly,
@@ -166,7 +166,9 @@ def _swift_compiler_plugin_impl(ctx):
                 files = ctx.files.data,
             ),
         ),
-        OutputGroupInfo(**output_groups),
+        OutputGroupInfo(
+            **supplemental_compilation_output_groups(supplemental_outputs)
+        ),
         SwiftCompilerPluginInfo(
             cc_info = CcInfo(
                 compilation_context = module_context.clang.compilation_context,

swift/swift_library.bzl

@@ -183,7 +183,7 @@ def _swift_library_impl(ctx):
 
     include_dev_srch_paths = include_developer_search_paths(ctx.attr)
 
-    module_context, cc_compilation_outputs, supplemental_outputs = swift_common.compile(
+    compile_result = swift_common.compile(
         actions = ctx.actions,
         additional_inputs = additional_inputs,
         cc_infos = get_providers(ctx.attr.deps, CcInfo),
@@ -204,12 +204,16 @@ def _swift_library_impl(ctx):
         workspace_name = ctx.workspace_name,
     )
 
+    module_context = compile_result.module_context
+    compilation_outputs = compile_result.compilation_outputs
+    supplemental_outputs = compile_result.supplemental_outputs
+
     linking_context, linking_output = (
         swift_common.create_linking_context_from_compilation_outputs(
             actions = ctx.actions,
             additional_inputs = additional_inputs,
             alwayslink = ctx.attr.alwayslink,
-            compilation_outputs = cc_compilation_outputs,
+            compilation_outputs = compilation_outputs,
             feature_configuration = feature_configuration,
             include_dev_srch_paths = include_dev_srch_paths,
             label = ctx.label,
@@ -255,9 +259,6 @@ def _swift_library_impl(ctx):
                 files = ctx.files.data,
             ),
         ),
-        OutputGroupInfo(**supplemental_compilation_output_groups(
-            supplemental_outputs,
-        )),
         CcInfo(
             compilation_context = module_context.clang.compilation_context,
             linking_context = linking_context,
@@ -274,6 +275,9 @@ def _swift_library_impl(ctx):
             # not propagate.
             swift_infos = swift_infos,
         ),
+        OutputGroupInfo(
+            **supplemental_compilation_output_groups(supplemental_outputs)
+        ),
     ]
 
     # Propagate an `apple_common.Objc` provider with linking info about the