Add CI tests for Build without the Bytes

.github/workflows/preflight_env.sh

@@ -15,6 +15,14 @@ if [[ "$*" == *--no-bzlmod* ]]; then
   echo "build --noenable_bzlmod" >> user.bazelrc
 fi
 
+# If `RULES_APPLE_SWIFT_VERSION` is set to `latest` use the master branch of rules_swift and rules_apple.
+if [[ "${RULES_APPLE_RULES_SWIFT_VERSION}" == "latest" ]]; then
+  gh repo clone bazelbuild/rules_swift /tmp/rules_swift
+  gh repo clone bazelbuild/rules_apple /tmp/rules_apple
+  echo "common --override_module=rules_swift=/tmp/rules_swift" >> user.bazelrc
+  echo "common --override_module=rules_apple=/tmp/rules_apple" >> user.bazelrc
+fi
+
 # Add the ci config override.
 echo "common --config=ci" >> user.bazelrc
 

.github/workflows/tests.yml

@@ -21,8 +21,8 @@ jobs:
       fail-fast: false
       matrix:
         bazel_version: [6.5.0, 7.1.0]
-        xcode_version: [15.2]
         virtual_frameworks: [true, false]
+        xcode_version: [15.2]
     env:
         XCODE_VERSION: ${{ matrix.xcode_version }}
         USE_BAZEL_VERSION: ${{ matrix.bazel_version }}
@@ -155,3 +155,67 @@ jobs:
             --config=ios_multi_arch_test \
             -- \
             tests/ios/app/App
+
+  build_without_the_bytes:
+    name: Build without the Bytes (Bazel ${{ matrix.bazel_version }} / Outputs level ${{matrix.download_outputs_level}} / rule versions ${{ matrix.rule_versions }} / Xcode ${{ matrix.xcode_version }})
+    runs-on: macos-14
+    strategy:
+      fail-fast: false
+      matrix:
+        bazel_version: [7.1.0]
+        download_outputs_level: ["minimal", "toplevel"]
+        rule_versions: ["current", "latest"]
+        xcode_version: [15.2]
+    env:
+        GH_TOKEN: ${{ github.token }}
+        RULES_APPLE_RULES_SWIFT_VERSION: ${{ matrix.rule_versions }}
+        USE_BAZEL_VERSION: ${{ matrix.bazel_version }}
+        XCODE_VERSION: ${{ matrix.xcode_version }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Preflight Env
+        run: .github/workflows/preflight_env.sh
+      - name: Build using Build without the Bytes
+        run: |
+          # non-iOS
+          bazelisk build \
+            --remote_download_outputs=${{matrix.download_outputs_level}} \
+            --disk_cache="/tmp/bazel-rules_ios-bwtb-cache" \
+            --remote_cache= \
+            -- \
+            //... \
+            -//tests/ios/...
+          # Clean the caches to test that BwtB works
+          bazel clean --expunge
+          # Run the same build again
+          bazelisk build \
+            --remote_download_outputs=${{matrix.download_outputs_level}} \
+            --disk_cache="/tmp/bazel-rules_ios-bwtb-cache" \
+            --remote_cache= \
+            -- \
+            //... \
+            -//tests/ios/...
+
+          # iOS
+          bazelisk build \
+            --config=ios \
+            --remote_download_outputs=${{matrix.download_outputs_level}} \
+            --disk_cache="/tmp/bazel-rules_ios-bwtb-ios-cache" \
+            --remote_cache= \
+            -- \
+            //tests/ios/...
+          # Clean the caches to test that BwtB works
+          bazel clean --expunge
+          # Run the same build again
+          bazelisk build \
+            --config=ios \
+            --remote_download_outputs=${{matrix.download_outputs_level}} \
+            --disk_cache="/tmp/bazel-rules_ios-bwtb-ios-cache" \
+            --remote_cache= \
+            -- \
+            //tests/ios/...
+      - uses: actions/upload-artifact@v4
+        if: failure()
+        with:
+          name: bazel-testlogs
+          path: bazel-testlogs

rules/framework.bzl

@@ -1017,6 +1017,11 @@ def _apple_framework_packaging_impl(ctx):
     objc_provider_utils.add_to_dict_if_present(compilation_context_fields, "headers", depset(
         direct = outputs.headers + outputs.private_headers + outputs.modulemaps,
     ))
+    objc_provider_utils.add_to_dict_if_present(
+        compilation_context_fields,
+        "direct_public_headers",
+        outputs.headers + outputs.modulemaps,
+    )
     objc_provider_utils.add_to_dict_if_present(compilation_context_fields, "defines", depset(
         direct = [],
         transitive = [getattr(cc_info.compilation_context, "defines") for cc_info in dep_cc_infos],
@@ -1211,13 +1216,6 @@ that this target depends on.
 """,
             cfg = transition_support.apple_platform_split_transition,
         ),
-        "_headermap_builder": attr.label(
-            executable = True,
-            cfg = "exec",
-            default = Label(
-                "//rules/hmap:hmaptool",
-            ),
-        ),
         "stamp": attr.int(
             mandatory = False,
             default = 0,

rules/framework/vfs_overlay.bzl

@@ -267,6 +267,8 @@ def _framework_vfs_overlay_impl(ctx):
             if VFSOverlayInfo in dep:
                 vfsoverlays.append(dep[VFSOverlayInfo].vfs_info)
 
+    vfs_overlay_file = ctx.actions.declare_file(ctx.label.name + ".yaml")
+
     vfs = make_vfsoverlay(
         ctx,
         hdrs = ctx.files.hdrs,
@@ -275,17 +277,21 @@ def _framework_vfs_overlay_impl(ctx):
         has_swift = ctx.attr.has_swift,
         swiftmodules = ctx.files.swiftmodules,
         merge_vfsoverlays = vfsoverlays,
-        output = ctx.outputs.vfsoverlay_file,
+        output = vfs_overlay_file,
         extra_search_paths = ctx.attr.extra_search_paths,
     )
 
     headers = depset([vfs.vfsoverlay_file])
     cc_info = CcInfo(
         compilation_context = cc_common.create_compilation_context(
             headers = headers,
+            direct_public_headers = [vfs.vfsoverlay_file],
         ),
     )
     return [
+        DefaultInfo(
+            files = depset([vfs_overlay_file]),
+        ),
         apple_common.new_objc_provider(),
         cc_info,
         VFSOverlayInfo(
@@ -446,7 +452,4 @@ toolchain (such as `clang`) will be retrieved.
     fragments = [
         "apple",
     ],
-    outputs = {
-        "vfsoverlay_file": "%{name}.yaml",
-    },
 )

rules/hmap.bzl

@@ -32,9 +32,16 @@ def _make_hmap(actions, headermap_builder, output, namespace, hdrs_lists):
     args.set_param_file_format(format = "multiline")
     args.use_param_file("@%s")
 
+    headers = [
+        header
+        for header_list in hdrs_lists
+        for header in header_list
+    ]
+
     actions.run(
         mnemonic = "HmapCreate",
         arguments = [args],
+        inputs = headers,
         executable = headermap_builder,
         outputs = [output],
     )
@@ -63,32 +70,34 @@ def _make_headermap_impl(ctx):
             # means neither apple_common.Objc nor CcInfo in hdr provider target
             fail("direct_hdr_provider %s must contain either 'CcInfo' or 'objc' provider" % provider)
 
+    headermap = ctx.actions.declare_file(ctx.label.name + ".hmap")
+
     hmap.make_hmap(
         actions = ctx.actions,
         headermap_builder = ctx.executable._headermap_builder,
-        output = ctx.outputs.headermap,
+        output = headermap,
         namespace = ctx.attr.namespace,
         hdrs_lists = hdrs_lists,
     )
 
     cc_info_provider = CcInfo(
         compilation_context = cc_common.create_compilation_context(
-            headers = depset([ctx.outputs.headermap]),
+            headers = depset([headermap]),
         ),
     )
 
     providers = [
+        DefaultInfo(
+            files = depset([headermap]),
+        ),
         apple_common.new_objc_provider(),
         cc_info_provider,
         swift_common.create_swift_info(),
+        HeaderMapInfo(
+            files = depset([headermap]),
+        ),
     ]
 
-    hdrs_lists = [l for l in hdrs_lists if l]
-    if len(hdrs_lists) > 0:
-        providers.append(HeaderMapInfo(
-            files = depset([ctx.outputs.headermap]),
-        ))
-
     return providers
 
 # Derive a headermap from transitive headermaps
@@ -119,7 +128,6 @@ headermap = rule(
             ),
         ),
     },
-    outputs = {"headermap": "%{name}.hmap"},
     doc = """\
 Creates a binary headermap file from the given headers,
 suitable for passing to clang.

rules/library.bzl

@@ -896,7 +896,7 @@ def apple_library(
             hdrs = objc_hdrs,
             tags = _MANUAL,
         )
-        private_dep_names.append(public_hmap_name)
+        deps += [public_hmap_name]
         additional_objc_copts, additional_swift_copts, additional_cc_copts = _append_headermap_copts(public_hmap_name, "-I", additional_objc_copts, additional_swift_copts, additional_cc_copts)
 
     if len(objc_non_exported_hdrs + objc_private_hdrs) > 0:
@@ -1033,7 +1033,7 @@ def apple_library(
                 tags = _MANUAL,
                 testonly = testonly,
             )
-            private_dep_names.append(swift_doublequote_hmap_name)
+            deps += [swift_doublequote_hmap_name]
             additional_objc_copts, additional_swift_copts, additional_cc_copts = _append_headermap_copts(swift_doublequote_hmap_name, "-iquote", additional_objc_copts, additional_swift_copts, additional_cc_copts)
 
             # Add generated swift header to header maps for angle bracket imports
@@ -1046,7 +1046,7 @@ def apple_library(
                 tags = _MANUAL,
                 testonly = testonly,
             )
-            private_dep_names.append(swift_angle_bracket_hmap_name)
+            deps += [swift_angle_bracket_hmap_name]
             additional_objc_copts, additional_swift_copts, additional_cc_copts = _append_headermap_copts(swift_angle_bracket_hmap_name, "-I", additional_objc_copts, additional_swift_copts, additional_cc_copts)
 
     if cpp_sources:

tests/ios/frameworks/mixed-source/custom-module-map/BUILD.bazel

@@ -11,7 +11,7 @@ apple_framework(
             "Sources/*.swift",
         ],
     ),
-    module_map = "Module Map/CustomModuleMap.modulemap",
+    module_map = "ModuleMap/CustomModuleMap.modulemap",
     objc_copts = ["-fcxx-modules"],
     platforms = {"ios": "13.0"},
     private_headers = ["Sources/PleaseDontImport.h"],