cc_toolchain's tool_map should be cfg-exec-configured

Copybara Import from #555

BEGIN_PUBLIC
cc_toolchain's tool_map should be cfg-exec-configured (#555)

However, it's not enough for `tool_map` to be on `cc_toolchain_config` - it must be on the toolchain itself to properly share the same exec platform as the action requesting the toolchain. Therefore we rearrange the implementation of the `cc_toolchain` macro to pass it to the rule, and teach the rule to accept it from either the attribute or the `cc_toolchain_config.` Eventually, `cc_toolchain_config` can be retired, though it will be a long journey.

Closes #555
END_PUBLIC

COPYBARA_INTEGRATE_REVIEW=#555 from dzbarsky:zbarsky/tool_map c964c48
PiperOrigin-RevId: 901427534
Change-Id: I18ae3b4d1bf7806717cadc5e31c743be9bd31e67

Author: dzbarsky

.bazelci/presubmit.yml

@@ -220,7 +220,10 @@ tasks:
       - "--enable_bzlmod"
       - "--ignore_dev_dependency"
 
-  ubuntu_rule_based_toolchains:
+# Rules-based toolchains
+  ubuntu_rule_based_toolchains_bazel_7:
+    name: Ubuntu rule-based toolchains (Bazel 7)
+    bazel: 7.2.1
     name: Ubuntu rule-based toolchains
     platform: ubuntu1804
     working_directory: examples/rule_based_toolchain
@@ -231,8 +234,53 @@ tasks:
     test_targets:
       - "//..."
 
-  macos_intel_rule_based_toolchains:
-    name: macOS rule-based toolchains
+  ubuntu_rule_based_toolchains_bazel_8:
+    name: Ubuntu rule-based toolchains (Bazel 8)
+    bazel: 8.5.0
+    platform: ubuntu1804
+    working_directory: examples/rule_based_toolchain
+    build_flags:
+      - "--enable_bzlmod"
+    build_targets:
+      - "//..."
+    test_targets:
+      - "//..."
+
+  ubuntu_rule_based_toolchains_bazel_9:
+    name: Ubuntu rule-based toolchains (Bazel 9)
+    bazel: 9.0.0rc3
+    platform: ubuntu1804
+    working_directory: examples/rule_based_toolchain
+    build_flags:
+      - "--enable_bzlmod"
+    build_targets:
+      - "//..."
+    test_targets:
+      - "//..."
+
+  macos_rule_based_toolchains_bazel_7:
+    name: macOS rule-based toolchains (Bazel 7)
+    bazel: 7.2.1
+    platform: macos
+    working_directory: examples/rule_based_toolchain
+    build_flags:
+      - "--enable_bzlmod"
+    build_targets:
+      - "//..."
+
+  macos_rule_based_toolchains_bazel_8:
+    name: macOS rule-based toolchains (Bazel 8)
+    bazel: 8.5.0
+    platform: macos
+    working_directory: examples/rule_based_toolchain
+    build_flags:
+      - "--enable_bzlmod"
+    build_targets:
+      - "//..."
+
+  macos_rule_based_toolchains_bazel_9:
+    name: macOS rule-based toolchains (Bazel 9)
+    bazel: 9.0.0rc3
     platform: macos
     working_directory: examples/rule_based_toolchain
     build_flags:

cc/BUILD

@@ -71,11 +71,15 @@ filegroup(
 
 filegroup(
     name = "srcs",
+    testonly = 1,
     srcs = glob([
         "**/*.bzl",
         "**/BUILD",
     ]) + [
+        "//cc/common:srcs",
         "//cc/private:srcs",
+        "//cc/toolchains:srcs",
+        "@bazel_skylib//:test_deps",
     ],
     visibility = ["//visibility:public"],
 )
@@ -194,6 +198,7 @@ bzl_library(
     deps = [
         ":build_settings_bzl",
         ":cc_postmark_bzl",
+        "//cc/toolchains:toolchain_rules",
         "@cc_compatibility_proxy//:proxy_bzl",
     ],
 )

cc/private/rules_impl/cc_toolchain.bzl

@@ -19,11 +19,21 @@ load("//cc/common:cc_helper.bzl", "cc_helper")
 load("//cc/common:semantics.bzl", "semantics")
 load("//cc/private/rules_impl/fdo:fdo_context.bzl", "create_fdo_context")
 load("//cc/toolchains:cc_toolchain_config_info.bzl", "CcToolchainConfigInfo")
+load("//cc/toolchains:cc_toolchain_info.bzl", "ActionTypeSetInfo", "FeatureSetInfo", "ToolConfigInfo")
+load("//cc/toolchains:legacy_file_group.bzl", "LEGACY_FILE_GROUPS")
+load("//cc/toolchains/impl:collect.bzl", "collect_action_types")
+load("//cc/toolchains/impl:toolchain_config.bzl", "CC_TOOLCHAIN_CONFIG_PUBLIC_ATTRS", "cc_toolchain_config_impl_helper")
 load(":cc_toolchain_provider_helper.bzl", "get_cc_toolchain_provider")
 
 ToolchainInfo = platform_common.ToolchainInfo
 TemplateVariableInfo = platform_common.TemplateVariableInfo
 
+LEGACY_ACTION_SET_DEPS = [
+    action
+    for actions in LEGACY_FILE_GROUPS.values()
+    for action in actions
+]
+
 def _files(ctx, attr_name):
     attr = getattr(ctx.attr, attr_name, None)
     files = []
@@ -81,42 +91,81 @@ def _attributes(ctx):
 
     latebound_libc = _latebound_libc(ctx, "libc_top", "_libc_top")
 
-    all_files = _files(ctx, "all_files")
+    if ctx.attr.toolchain_config:
+        for key in CC_TOOLCHAIN_CONFIG_PUBLIC_ATTRS.keys():
+            if getattr(ctx.attr, key):
+                fail("Must not pass %s when passing `toolchain_config`" % key)
+
+        cc_toolchain_config_info = ctx.attr.toolchain_config[CcToolchainConfigInfo]
+        all_files = _files(ctx, "all_files")
+
+        legacy_file_groups = {
+            "as_files": _files(ctx, "as_files"),
+            "ar_files": _files(ctx, "ar_files"),
+            "dwp_files": _files(ctx, "dwp_files"),
+            "compiler_files": _files(ctx, "compiler_files"),
+            "strip_files": _files(ctx, "strip_files"),
+            "objcopy_files": _files(ctx, "objcopy_files"),
+            "coverage_files": _files(ctx, "coverage_files") or all_files,
+        }
+
+        linker_files = _files(ctx, "linker_files")
+
+    else:
+        if not ctx.attr.tool_map:
+            fail("Must pass `tool_map` when not passing `toolchain_config`")
+        toolchain_config_info, cc_toolchain_config_info = cc_toolchain_config_impl_helper(ctx)
+
+        legacy_action_set_lookup = {
+            target.label: target
+            for target in ctx.attr._legacy_action_sets
+        }
+
+        legacy_file_groups = {}
+        for group, actions in LEGACY_FILE_GROUPS.items():
+            action_targets = [
+                legacy_action_set_lookup[action]
+                for action in actions
+            ]
+            legacy_file_groups[group] = depset(transitive = [
+                toolchain_config_info.files[action]
+                for action in collect_action_types(action_targets).to_list()
+                if action in toolchain_config_info.files
+            ])
+
+        all_files = depset(transitive = legacy_file_groups.values())
+        legacy_file_groups["coverage_files"] = legacy_file_groups["coverage_files"] or all_files
+        linker_files = legacy_file_groups.pop("linker_files")
+
     return struct(
         supports_param_files = ctx.attr.supports_param_files,
         runtime_solib_dir_base = "_solib__" + cc_common.escape_label(label = ctx.label),
-        cc_toolchain_config_info = _provider(ctx.attr.toolchain_config, CcToolchainConfigInfo),
+        cc_toolchain_config_info = cc_toolchain_config_info,
         static_runtime_lib = ctx.attr.static_runtime_lib,
         dynamic_runtime_lib = ctx.attr.dynamic_runtime_lib,
         supports_header_parsing = ctx.attr.supports_header_parsing,
         all_files = all_files,
-        compiler_files = _files(ctx, "compiler_files"),
-        strip_files = _files(ctx, "strip_files"),
-        objcopy_files = _files(ctx, "objcopy_files"),
         link_dynamic_library_tool = ctx.file._link_dynamic_library_tool,
         grep_includes = grep_includes,
         aggregate_ddi = _single_file(ctx, "_aggregate_ddi"),
         generate_modmap = _single_file(ctx, "_generate_modmap"),
         module_map = ctx.attr.module_map,
-        as_files = _files(ctx, "as_files"),
-        ar_files = _files(ctx, "ar_files"),
-        dwp_files = _files(ctx, "dwp_files"),
         module_map_artifact = _single_file(ctx, "module_map"),
-        all_files_including_libc = depset(transitive = [_files(ctx, "all_files"), _files(ctx, latebound_libc)]),
+        all_files_including_libc = depset(transitive = [all_files, _files(ctx, latebound_libc)]),
         zipper = ctx.file._zipper,
         linker_files = _full_inputs_for_link(
             ctx,
-            _files(ctx, "linker_files"),
+            linker_files,
             _files(ctx, latebound_libc),
         ),
         cc_toolchain_label = ctx.label,
-        coverage_files = _files(ctx, "coverage_files") or all_files,
         compiler_files_without_includes = _files(ctx, "compiler_files_without_includes"),
         libc = _files(ctx, latebound_libc),
         libc_top_label = _label(ctx, latebound_libc),
         if_so_builder = ctx.file._interface_library_builder,
         allowlist_for_layering_check = _package_specification_provider(ctx, "disabling_parse_headers_and_layering_check_allowed"),
         build_info_files = _provider(ctx.attr._build_info_translator, OutputGroupInfo),
+        **legacy_file_groups
     )
 
 def _cc_toolchain_impl(ctx):
@@ -200,7 +249,6 @@ crosstool_config.toolchain.
         ),
         "all_files": attr.label(
             allow_files = True,
-            mandatory = True,
             doc = """
 Collection of all cc_toolchain artifacts. These artifacts will be added as inputs to all
 rules_cc related actions (with the exception of actions that are using more precise sets of
@@ -214,7 +262,6 @@ rules using C++ toolchain.</p>""",
         ),
         "compiler_files": attr.label(
             allow_files = True,
-            mandatory = True,
             doc = """
 Collection of all cc_toolchain artifacts required for compile actions.""",
         ),
@@ -226,13 +273,11 @@ input discovery is supported (currently Google-only).""",
         ),
         "strip_files": attr.label(
             allow_files = True,
-            mandatory = True,
             doc = """
 Collection of all cc_toolchain artifacts required for strip actions.""",
         ),
         "objcopy_files": attr.label(
             allow_files = True,
-            mandatory = True,
             doc = """
 Collection of all cc_toolchain artifacts required for objcopy actions.""",
         ),
@@ -248,13 +293,11 @@ Collection of all cc_toolchain artifacts required for archiving actions.""",
         ),
         "linker_files": attr.label(
             allow_files = True,
-            mandatory = True,
             doc = """
 Collection of all cc_toolchain artifacts required for linking actions.""",
         ),
         "dwp_files": attr.label(
             allow_files = True,
-            mandatory = True,
             doc = """
 Collection of all cc_toolchain artifacts required for dwp actions.""",
         ),
@@ -307,7 +350,6 @@ Set to True when cc_toolchain supports header parsing actions.""",
         ),
         "toolchain_config": attr.label(
             allow_files = False,
-            mandatory = True,
             providers = [CcToolchainConfigInfo],
             doc = """
 The label of the rule providing <code>cc_toolchain_config_info</code>.""",
@@ -340,5 +382,16 @@ The label of the rule providing <code>cc_toolchain_config_info</code>.""",
             default = semantics.BUILD_INFO_TRANLATOR_LABEL,
             providers = [OutputGroupInfo],
         ),
+        "_legacy_action_sets": attr.label_list(
+            default = LEGACY_ACTION_SET_DEPS,
+            providers = [ActionTypeSetInfo],
+        ),
+    } | CC_TOOLCHAIN_CONFIG_PUBLIC_ATTRS | {
+        # Override tool_map to make it optional and exec-configured.
+        "tool_map": attr.label(
+            cfg = "exec",
+            providers = [ToolConfigInfo],
+        ),
+        "_builtin_features": attr.label(default = "//cc/toolchains/features:all_builtin_features", providers = [FeatureSetInfo]),
     } | semantics.cpp_modules_tools(),  # buildifier: disable=unsorted-dict-items
 )

cc/toolchains/cc_toolchain_info.bzl

@@ -18,6 +18,7 @@
 # Once it's stabilized, we *may* consider opening up parts of the API, or we may
 # decide to just require users to use the public user-facing rules.
 visibility([
+    "//cc/private/rules_impl/...",
     "//cc/toolchains/...",
     "//tests/rule_based_toolchain/...",
 ])

cc/toolchains/impl/collect.bzl

@@ -22,6 +22,7 @@ load(
 )
 
 visibility([
+    "//cc/private/rules_impl/...",
     "//cc/toolchains/...",
     "//tests/rule_based_toolchain/...",
 ])

cc/toolchains/impl/toolchain_config.bzl

@@ -29,6 +29,7 @@ load(":legacy_converter.bzl", "convert_toolchain")
 load(":toolchain_config_info.bzl", "toolchain_config_info")
 
 visibility([
+    "//cc/private/rules_impl/...",
     "//cc/toolchains/...",
     "//tests/rule_based_toolchain/...",
 ])
@@ -50,7 +51,14 @@ cc_legacy_file_group = rule(
     },
 )
 
-def _cc_toolchain_config_impl(ctx):
+def cc_toolchain_config_impl_helper(ctx):
+    """Main implementation for _cc_toolchain_config_impl, reused for rules-based toolchains
+
+    Args:
+      ctx: Rule context
+    Returns:
+        toolchain_config_info and cc_toolchain_config_info providers"""
+
     if ctx.attr.features:
         fail("Features is a reserved attribute in bazel. Did you mean 'known_features' or 'enabled_features'?")
 
@@ -66,7 +74,7 @@ def _cc_toolchain_config_impl(ctx):
 
     legacy = convert_toolchain(toolchain_config)
 
-    return [
+    return (
         toolchain_config,
         cc_common.create_cc_toolchain_config_info(
             ctx = ctx,
@@ -90,6 +98,13 @@ def _cc_toolchain_config_impl(ctx):
             abi_version = "",
             abi_libc_version = "",
         ),
+    )
+
+def _cc_toolchain_config_impl(ctx):
+    toolchain_config, cc_toolchain_config_info = cc_toolchain_config_impl_helper(ctx)
+    return [
+        toolchain_config,
+        cc_toolchain_config_info,
         # This allows us to support all_files.
         # If all_files was simply an alias to
         # //cc/toolchains/actions:all_actions,
@@ -98,19 +113,21 @@ def _cc_toolchain_config_impl(ctx):
         DefaultInfo(files = depset(transitive = toolchain_config.files.values())),
     ]
 
+CC_TOOLCHAIN_CONFIG_PUBLIC_ATTRS = {
+    # Attributes new to this rule.
+    "compiler": attr.string(default = ""),
+    "cpu": attr.string(default = ""),
+    "tool_map": attr.label(providers = [ToolConfigInfo], mandatory = True),
+    "args": attr.label_list(providers = [ArgsListInfo]),
+    "known_features": attr.label_list(providers = [FeatureSetInfo]),
+    "enabled_features": attr.label_list(providers = [FeatureSetInfo]),
+    "artifact_name_patterns": attr.label_list(providers = [ArtifactNamePatternInfo]),
+    "make_variables": attr.label_list(providers = [MakeVariableInfo]),
+}
+
 cc_toolchain_config = rule(
     implementation = _cc_toolchain_config_impl,
-    # @unsorted-dict-items
-    attrs = {
-        # Attributes new to this rule.
-        "compiler": attr.string(default = ""),
-        "cpu": attr.string(default = ""),
-        "tool_map": attr.label(providers = [ToolConfigInfo], mandatory = True),
-        "args": attr.label_list(providers = [ArgsListInfo]),
-        "known_features": attr.label_list(providers = [FeatureSetInfo]),
-        "enabled_features": attr.label_list(providers = [FeatureSetInfo]),
-        "artifact_name_patterns": attr.label_list(providers = [ArtifactNamePatternInfo]),
-        "make_variables": attr.label_list(providers = [MakeVariableInfo]),
+    attrs = CC_TOOLCHAIN_CONFIG_PUBLIC_ATTRS | {
         "_builtin_features": attr.label(default = "//cc/toolchains/features:all_builtin_features"),
     },
     provides = [ToolchainConfigInfo],