Include all necessary sources in prebuild test data.

For cc compilation, we need access to a number of sources from the workspace, from both the target dependencies and from the cc toolchain. Add these to the `sources` directory created by the `test_data` rule.

To achieve this, add some explicit `test_mode` support to the existing cc rules in `build_dependencies.bzl` and export all the required sourcs to `test_projects.bzl` which can then add them to the `sources` directory.

Also add the cc related output groups to the `OutputInfo` returned by `PrebuiltProjectFakeDependencyBuilder` so that it behaves more like the real implementation.

PiperOrigin-RevId: 578519803

aspect/build_dependencies.bzl

@@ -57,10 +57,11 @@ DependenciesInfo = provider(
         "target_to_artifacts": "a map between a target and all its artifacts",
         "aars": "a list of aars with resource files",
         "gensrcs": "a list of sources generated by project targets",
-        "test_mode_own_files": "a structure describing artifacts required when the target is requested within the project scope",
         "cc_info": "a structure containing info required to compile cc sources",
         "cc_headers": "a list of generated headers required to compile cc sources",
         "cc_toolchain_info": "struct containing cc toolchain info, with keys file (the output file) and id (unique ID for the toolchain info, referred to from elsewhere)",
+        "test_mode_own_files": "a structure describing Java artifacts required when the target is requested within the project scope",
+        "test_mode_cc_src_deps": "a list of sources (e.g. headers) required to compile cc sources in integratrion tests",
     },
 )
 
@@ -69,20 +70,22 @@ def create_dependencies_info(
         target_to_artifacts = {},
         aars = depset(),
         gensrcs = depset(),
-        test_mode_own_files = None,
         cc_info = None,
         cc_headers = depset(),
-        cc_toolchain_info = None):
+        cc_toolchain_info = None,
+        test_mode_own_files = None,
+        test_mode_cc_src_deps = depset()):
     """A helper function to create a DependenciesInfo provider instance."""
     return DependenciesInfo(
         compile_time_jars = compile_time_jars,
         target_to_artifacts = target_to_artifacts,
         aars = aars,
         gensrcs = gensrcs,
-        test_mode_own_files = test_mode_own_files,
         cc_info = cc_info,
         cc_headers = cc_headers,
         cc_toolchain_info = cc_toolchain_info,
+        test_mode_own_files = test_mode_own_files,
+        test_mode_cc_src_deps = test_mode_cc_src_deps,
     )
 
 def _encode_target_info_proto(target_to_artifacts):
@@ -367,17 +370,26 @@ def _get_followed_cc_dependency_info(rule):
             return cc_toolchain_target[DependenciesInfo]
     return None
 
-def _collect_own_and_dependency_cc_info(target, dependency_info):
+def _collect_own_and_dependency_cc_info(target, dependency_info, test_mode):
     compilation_context = target[CcInfo].compilation_context
     cc_toolchain_info = None
+    tets_mode_cc_src_deps = depset()
     if dependency_info:
         cc_toolchain_info = dependency_info.cc_toolchain_info
+        if test_mode:
+            tets_mode_cc_src_deps = dependency_info.test_mode_cc_src_deps
 
     gen_headers = depset()
     compilation_info = None
     if compilation_context:
         gen_headers = depset([f for f in compilation_context.headers.to_list() if not f.is_source])
 
+        if test_mode:
+            tets_mode_cc_src_deps = depset(
+                [f for f in compilation_context.headers.to_list() if f.is_source],
+                transitive = [tets_mode_cc_src_deps],
+            )
+
         compilation_info = struct(
             transitive_defines = compilation_context.defines.to_list(),
             transitive_include_directory = compilation_context.includes.to_list(),
@@ -390,6 +402,7 @@ def _collect_own_and_dependency_cc_info(target, dependency_info):
     return struct(
         compilation_info = compilation_info,
         gen_headers = gen_headers,
+        tets_mode_cc_src_deps = tets_mode_cc_src_deps,
         cc_toolchain_info = cc_toolchain_info,
     )
 
@@ -411,7 +424,7 @@ def _collect_dependencies_core_impl(
         test_mode,
     )
     if CcInfo in target:
-        dep_infos.append(_collect_cc_dependencies_core_impl(target, ctx))
+        dep_infos.append(_collect_cc_dependencies_core_impl(target, ctx, test_mode))
     if cc_common.CcToolchainInfo in target:
         dep_infos.append(_collect_cc_toolchain_info(target, ctx))
     return dep_infos
@@ -462,15 +475,16 @@ def _collect_java_dependencies_core_impl(
         ),
     ]
 
-def _collect_cc_dependencies_core_impl(target, ctx):
+def _collect_cc_dependencies_core_impl(target, ctx, test_mode):
     dependency_info = _get_followed_cc_dependency_info(ctx.rule)
 
-    cc_info = _collect_own_and_dependency_cc_info(target, dependency_info)
+    cc_info = _collect_own_and_dependency_cc_info(target, dependency_info, test_mode)
 
     return create_dependencies_info(
         cc_info = cc_info.compilation_info,
         cc_headers = cc_info.gen_headers,
         cc_toolchain_info = cc_info.cc_toolchain_info,
+        test_mode_cc_src_deps = cc_info.tets_mode_cc_src_deps,
     )
 
 def _collect_cc_toolchain_info(target, ctx):
@@ -540,6 +554,7 @@ def _collect_cc_toolchain_info(target, ctx):
 
     return create_dependencies_info(
         cc_toolchain_info = struct(file = cc_toolchain_file, id = toolchain_id),
+        test_mode_cc_src_deps = depset([f for f in toolchain_info.all_files.to_list() if f.is_source]),
     )
 
 def _get_ide_aar_file(target, ctx):