Allow bootstrapping stdlib from source (#118)

Author: dzbarsky

MODULE.bazel

@@ -58,7 +58,7 @@ bazel_dep(name = "protobuf", version = "34.0.bcr.1", repo_name = "com_google_pro
 bazel_dep(name = "rules_cc", version = "0.2.8")
 bazel_dep(name = "rules_proto", version = "7.1.0")
 bazel_dep(name = "rules_python", version = "1.6.3")
-bazel_dep(name = "llvm", version = "0.7.7")
+bazel_dep(name = "llvm", version = "0.8.0")
 bazel_dep(name = "aspect_tools_telemetry", version = "0.3.3")
 
 osx = use_extension("@llvm//extensions:osx.bzl", "osx")

MODULE.bazel.lock

@@ -123,7 +123,7 @@ def _generate_hub_and_spokes(
 
     mctx.report_progress("Reading workspace metadata")
     result = mctx.execute(
-        [cargo_path, "metadata", "--no-deps", "--format-version=1", "--quiet"],
+        [cargo_path, "metadata", "--no-deps", "--locked", "--format-version=1", "--quiet"],
         working_directory = str(mctx.path(cargo_lock_path).dirname),
     )
     if result.return_code != 0:
@@ -255,7 +255,6 @@ def _generate_hub_and_spokes(
 
     workspace_resolution = resolve_cargo_workspace_members(
         mctx,
-        hub_name = hub_name,
         cargo_metadata = cargo_metadata,
         packages = packages,
         workspace_members = workspace_members,
@@ -266,6 +265,7 @@ def _generate_hub_and_spokes(
         materialize_workspace_members = False,
         validate_lockfile = validate_lockfile,
         debug = debug,
+        dep_label_prefix = "@%s//:" % hub_name,
         watch_manifests = watch_manifests,
         use_legacy_rules_rust_platforms = use_legacy_rules_rust_platforms,
     )

rs/extensions.bzl

@@ -1,8 +1,8 @@
 """Config settings for Rust target triples."""
 
-load("//rs/platforms:triples.bzl", "SUPPORTED_TARGET_TRIPLES", "triple_to_constraint_set")
+load("//rs/platforms:triples.bzl", "ALL_TARGET_TRIPLES", "triple_to_constraint_set")
 
-def declare_config_settings(targets = SUPPORTED_TARGET_TRIPLES):
+def declare_config_settings(targets = ALL_TARGET_TRIPLES):
     for target_triple in targets:
         native.config_setting(
             name = target_triple,

rs/platforms/config/declare_config_settings.bzl

@@ -1,8 +1,8 @@
 """Platform definitions for Rust target triples."""
 
-load("//rs/platforms:triples.bzl", "SUPPORTED_TARGET_TRIPLES", "triple_to_constraint_set")
+load("//rs/platforms:triples.bzl", "ALL_TARGET_TRIPLES", "triple_to_constraint_set")
 
-def declare_platforms(targets = SUPPORTED_TARGET_TRIPLES):
+def declare_platforms(targets = ALL_TARGET_TRIPLES):
     for target_triple in targets:
         native.platform(
             name = target_triple,

rs/platforms/declare_platforms.bzl

@@ -36,7 +36,7 @@ SUPPORTED_EXEC_TRIPLES = [
 ]
 
 # See https://doc.rust-lang.org/beta/rustc/platform-support.html
-SUPPORTED_TARGET_TRIPLES = [
+SUPPORTED_TIER_1_AND_2_TRIPLES = [
     # Tier 1
     "aarch64-apple-darwin",  # ARM64 macOS (11.0+, Big Sur+)
     "aarch64-pc-windows-msvc",  # ARM64 Windows MSVC
@@ -142,6 +142,40 @@ SUPPORTED_TARGET_TRIPLES = [
     "x86_64-unknown-none",  # * Freestanding/bare-metal x86_64, softfloat
     #"x86_64-unknown-redox",             # ✓ Redox OS
     "x86_64-unknown-uefi",  # ? 64-bit UEFI
+]
 
-    # No Tier3 support.
+SUPPORTED_TIER_3_TRIPLES = [
+    "aarch64-unknown-freebsd",
+    "aarch64-unknown-netbsd",
+    "aarch64-unknown-nto-qnx710",
+    "aarch64-unknown-openbsd",
+    "arm64e-apple-darwin",
+    "arm64e-apple-ios",
+    "armv7-unknown-freebsd",
+    "armv7-unknown-netbsd-eabihf",
+    "bpfeb-unknown-none",
+    "bpfel-unknown-none",
+    "i386-apple-ios",
+    "i686-apple-darwin",
+    "i686-unknown-netbsd",
+    "i686-unknown-openbsd",
+    "powerpc-unknown-freebsd",
+    "powerpc-unknown-linux-musl",
+    "powerpc-unknown-netbsd",
+    "powerpc-unknown-openbsd",
+    "powerpc64-unknown-freebsd",
+    "powerpc64-unknown-openbsd",
+    "powerpc64le-unknown-freebsd",
+    "riscv64-linux-android",
+    "riscv64gc-unknown-freebsd",
+    "riscv64gc-unknown-fuchsia",
+    "riscv64gc-unknown-netbsd",
+    "riscv64gc-unknown-openbsd",
+    "s390x-unknown-linux-musl",
+    "sparc64-unknown-netbsd",
+    "sparc64-unknown-openbsd",
+    "wasm64-unknown-unknown",
+    "x86_64-unknown-openbsd",
 ]
+
+ALL_TARGET_TRIPLES = SUPPORTED_TIER_1_AND_2_TRIPLES + SUPPORTED_TIER_3_TRIPLES

rs/platforms/triples.bzl

@@ -1,11 +1,28 @@
 load("@bazel_lib//:bzl_library.bzl", "bzl_library")
+load("@bazel_skylib//rules:common_settings.bzl", "bool_setting")
+load("@rules_rust//rust:defs.bzl", "rust_stdlib_filegroup")
 load(":all_crate_deps_test.bzl", "all_crate_deps_tests")
+load(":cargo_workspace_graph_test.bzl", "cargo_workspace_graph_tests")
 load(":cfg_parser_test.bzl", "cfg_parser_tests")
 load(":lint_flags_test.bzl", "lint_flags_tests")
 load(":semver_test.bzl", "semver_select_tests")
 
+bool_setting(
+    name = "source_stdlib_building",
+    build_setting_default = False,
+    visibility = ["//visibility:public"],
+)
+
+rust_stdlib_filegroup(
+    name = "empty_stdlib",
+    srcs = [],
+    visibility = ["//visibility:public"],
+)
+
 all_crate_deps_tests()
 
+cargo_workspace_graph_tests()
+
 cfg_parser_tests()
 
 lint_flags_tests()
@@ -108,6 +125,13 @@ bzl_library(
     deps = ["@bazel_lib//lib:repo_utils"],
 )
 
+bzl_library(
+    name = "source_stdlib",
+    srcs = ["source_stdlib.bzl"],
+    visibility = ["//rs:__subpackages__"],
+    deps = ["@rules_rust//rust:bzl_lib"],
+)
+
 bzl_library(
     name = "git_cargo_workspace_repository",
     srcs = ["git_cargo_workspace_repository.bzl"],
@@ -173,6 +197,21 @@ bzl_library(
     ],
 )
 
+bzl_library(
+    name = "rustc_src_repository",
+    srcs = ["rustc_src_repository.bzl"],
+    visibility = ["//rs:__subpackages__"],
+    deps = [
+        ":cargo_workspace_graph",
+        ":repository_utils",
+        ":toml2json",
+        "//rs/platforms:triples",
+        "@bazel_skylib//lib:paths",
+        "@bazel_tools//tools/build_defs/repo:utils.bzl",
+        "@rules_rust//rust/private:bzl_lib",
+    ],
+)
+
 bzl_library(
     name = "rustc_repository",
     srcs = ["rustc_repository.bzl"],