Add buck2 CI

.buckconfig

@@ -1,23 +1,17 @@
+[repositories]
+repo = .
+prelude = tools/buck/buck2/prelude
+toolchains = tools/buck/toolchains
+ovr_config = tools/buck/buck2/prelude
+buck = none
+fbcode = none
+fbsource = none
+
 [project]
-  # We use some symlinks in the source tree, but they get eliminated by `cargo
-  # publish` and `cargo vendor` so this allow_symlinks setting should not be
-  # required downstream.
-  allow_symlinks = allow
+# Hide BUCK files under target/package/ from `buck build ...`. Otherwise:
+#   $ buck build ...
+#   //target/package/cxx-0.3.0/tests:ffi references non-existing file or directory 'target/package/cxx-0.3.0/tests/ffi/lib.rs'
+ignore = target
 
-  # Hide BUCK files under target/package/ from `buck build ...`. Otherwise:
-  #   $ buck build ...
-  #   //target/package/cxx-0.3.0/tests:ffi references non-existing file or directory 'target/package/cxx-0.3.0/tests/ffi/lib.rs'
-  ignore = target
-
-[cxx]
-  cxxflags = -std=c++11
-
-[rust]
-  default_edition = required
-  rustc_flags = \
-      -Clink-arg=-fuse-ld=lld \
-      -Crelocation-model=dynamic-no-pic \
-      --cap-lints=allow
-
-[defaults.rust_library]
-  type = check
+[parser]
+target_platform_detector_spec = target://...->ovr_config//platforms:default

.buckversion

@@ -1 +0,0 @@
-last

.github/workflows/ci.yml

@@ -62,6 +62,26 @@ jobs:
         env:
           RUSTFLAGS: --cfg compile_error_if_alloc --cfg cxx_experimental_no_alloc ${{env.RUSTFLAGS}}
 
+  buck:
+    name: Buck
+    runs-on: ubuntu-latest
+    if: github.event_name != 'pull_request'
+    timeout-minutes: 45
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
+      - uses: dtolnay/rust-toolchain@nightly
+      - uses: dtolnay/install@buck2
+      - name: Install lld
+        run: sudo apt-get install lld
+      - name: Vendor dependencies
+        run: |
+          cp third-party/Cargo.lock .
+          cargo vendor --versioned-dirs --locked third-party/vendor
+      - run: buck2 run demo
+      - run: buck2 build ...
+
   bazel:
     name: Bazel
     runs-on: ubuntu-latest

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "tools/buck/buck2"]
+	path = tools/buck/buck2
+	url = https://github.com/facebookincubator/buck2

BUCK

@@ -15,7 +15,10 @@ rust_library(
 
 rust_binary(
     name = "codegen",
-    srcs = glob(["gen/cmd/src/**/*.rs"]) + ["gen/cmd/src/gen/include/cxx.h"],
+    srcs = glob(["gen/cmd/src/**/*.rs"]) + [
+        "gen/cmd/src/gen",
+        "gen/cmd/src/syntax",
+    ],
     crate = "cxxbridge",
     edition = "2018",
     visibility = ["PUBLIC"],
@@ -41,7 +44,7 @@ cxx_library(
 
 rust_library(
     name = "macro",
-    srcs = glob(["macro/src/**/*.rs"]),
+    srcs = glob(["macro/src/**/*.rs"]) + ["macro/src/syntax"],
     crate = "cxxbridge_macro",
     edition = "2018",
     proc_macro = True,
@@ -54,7 +57,10 @@ rust_library(
 
 rust_library(
     name = "build",
-    srcs = glob(["gen/build/src/**/*.rs"]),
+    srcs = glob(["gen/build/src/**/*.rs"]) + [
+        "gen/build/src/gen",
+        "gen/build/src/syntax",
+    ],
     edition = "2018",
     visibility = ["PUBLIC"],
     deps = [
@@ -70,7 +76,10 @@ rust_library(
 
 rust_library(
     name = "lib",
-    srcs = glob(["gen/lib/src/**/*.rs"]),
+    srcs = glob(["gen/lib/src/**/*.rs"]) + [
+        "gen/lib/src/gen",
+        "gen/lib/src/syntax",
+    ],
     edition = "2018",
     visibility = ["PUBLIC"],
     deps = [

demo/BUCK

@@ -29,6 +29,6 @@ cxx_library(
 
 cxx_library(
     name = "blobstore-include",
+    exported_deps = ["//:core"],
     exported_headers = ["include/blobstore.h"],
-    deps = ["//:core"],
 )

tests/BUCK

@@ -32,20 +32,26 @@ cxx_library(
         ":bridge/source",
         ":module/source",
     ],
-    headers = {
+    exported_deps = ["//:core"],
+    exported_headers = {
         "ffi/lib.rs.h": ":bridge/header",
         "ffi/module.rs.h": ":module/header",
         "ffi/tests.h": "ffi/tests.h",
     },
-    deps = ["//:core"],
 )
 
 rust_cxx_bridge(
     name = "bridge",
     src = "ffi/lib.rs",
+    deps = [
+        ":impl",
+    ],
 )
 
 rust_cxx_bridge(
     name = "module",
     src = "ffi/module.rs",
+    deps = [
+        ":impl",
+    ],
 )

tools/buck/buck2

@@ -0,0 +1 @@
+Subproject commit c117530548ddc3ec1e85b5af52e5fe678b32dff0

tools/buck/genrule.bzl

@@ -1,8 +0,0 @@
-def genrule(cmd, **kwargs):
-    # Resolve a distracting inconsistency between Buck and Bazel.
-    # Bazel creates the directory for your output file, while Buck expects the
-    # cmd to create it.
-    #
-    # TODO: send this as a PR to Buck, because Bazel's behavior here is better.
-    cmd = "mkdir -p `dirname ${OUT}`; " + cmd
-    native.genrule(cmd = cmd, **kwargs)

tools/buck/rust_cxx_bridge.bzl

@@ -1,19 +1,17 @@
-load("//tools/buck:genrule.bzl", "genrule")
-
 def rust_cxx_bridge(name, src, deps = []):
-    genrule(
+    native.genrule(
         name = "%s/header" % name,
         out = src + ".h",
         cmd = "cp $(location :%s/generated)/generated.h ${OUT}" % name,
     )
 
-    genrule(
+    native.genrule(
         name = "%s/source" % name,
         out = src + ".cc",
         cmd = "cp $(location :%s/generated)/generated.cc ${OUT}" % name,
     )
 
-    genrule(
+    native.genrule(
         name = "%s/generated" % name,
         srcs = [src],
         out = ".",
@@ -21,14 +19,14 @@ def rust_cxx_bridge(name, src, deps = []):
         type = "cxxbridge",
     )
 
-    cxx_library(
+    native.cxx_library(
         name = name,
         srcs = [":%s/source" % name],
         preferred_linkage = "static",
-        deps = deps + [":%s/include" % name],
+        exported_deps = deps + [":%s/include" % name],
     )
 
-    cxx_library(
+    native.cxx_library(
         name = "%s/include" % name,
         exported_headers = [":%s/header" % name],
     )

tools/buck/rust_library.bzl

@@ -1,5 +1,3 @@
-load("//tools/buck:genrule.bzl", "genrule")
-
 def rust_library(
         name,
         srcs,
@@ -9,7 +7,7 @@ def rust_library(
         build_script = None,
         **kwargs):
     if build_script:
-        rust_binary(
+        native.rust_binary(
             name = "%s@build" % name,
             srcs = srcs + [build_script],
             crate = "build",
@@ -19,7 +17,7 @@ def rust_library(
             rustc_flags = rustc_flags,
         )
 
-        genrule(
+        native.genrule(
             name = "%s@cfg" % name,
             out = "output",
             cmd = "env RUSTC=rustc TARGET= $(exe :%s@build) | sed -n s/^cargo:rustc-cfg=/--cfg=/p > ${OUT}" % name,

tools/buck/toolchains/BUCK

@@ -0,0 +1,16 @@
+load(":toolchain.bzl", "cxx_toolchain", "python_bootstrap_toolchain", "rust_toolchain")
+
+cxx_toolchain(
+    name = "cxx",
+    visibility = ["PUBLIC"],
+)
+
+python_bootstrap_toolchain(
+    name = "python_bootstrap",
+    visibility = ["PUBLIC"],
+)
+
+rust_toolchain(
+    name = "rust",
+    visibility = ["PUBLIC"],
+)

tools/buck/toolchains/toolchain.bzl

@@ -0,0 +1,118 @@
+load(
+    "@prelude//cxx:cxx_toolchain_types.bzl",
+    "BinaryUtilitiesInfo",
+    "CCompilerInfo",
+    "CxxCompilerInfo",
+    "CxxPlatformInfo",
+    "CxxToolchainInfo",
+    "LinkerInfo",
+)
+load("@prelude//cxx:headers.bzl", "HeaderMode")
+load("@prelude//linking:link_info.bzl", "LinkStyle")
+load("@prelude//python_bootstrap:python_bootstrap.bzl", "PythonBootstrapToolchainInfo")
+load("@prelude//rust:rust_toolchain.bzl", "RustPlatformInfo", "RustToolchainInfo")
+
+DEFAULT_MAKE_COMP_DB = "@prelude//cxx/tools:make_comp_db"
+
+def _cxx_toolchain(ctx):
+    """
+    A very simple toolchain that is hardcoded to the current environment.
+    """
+    return [
+        DefaultInfo(),
+        CxxToolchainInfo(
+            mk_comp_db = ctx.attrs.make_comp_db,
+            linker_info = LinkerInfo(
+                linker = RunInfo(args = ["g++"]),
+                linker_flags = ["-lstdc++"],
+                archiver = RunInfo(args = ["ar", "rcs"]),
+                type = "gnu",
+                link_binaries_locally = True,
+                archive_objects_locally = True,
+                use_archiver_flags = False,
+                static_dep_runtime_ld_flags = [],
+                static_pic_dep_runtime_ld_flags = [],
+                shared_dep_runtime_ld_flags = [],
+                independent_shlib_interface_linker_flags = [],
+                mk_shlib_intf = ctx.attrs.make_shlib_intf,
+                link_style = LinkStyle(ctx.attrs.link_style),
+                link_weight = 1,
+                binary_extension = "",
+                object_file_extension = "o",
+                shared_library_name_format = "lib{}.so",
+                shared_library_versioned_name_format = "lib{}.so.{}",
+                static_library_extension = "a",
+            ),
+            binary_utilities_info = BinaryUtilitiesInfo(
+                nm = RunInfo(args = ["nm"]),
+                ranlib = RunInfo(args = ["raninfo"]),
+                strip = RunInfo(args = ["strip"]),
+            ),
+            cxx_compiler_info = CxxCompilerInfo(
+                compiler = RunInfo(args = ["clang++"]),
+                preprocessor_flags = [],
+                compiler_flags = [],
+                compiler_type = "clang",
+            ),
+            c_compiler_info = CCompilerInfo(
+                preprocessor_flags = [],
+            ),
+            header_mode = HeaderMode("symlink_tree_only"),
+        ),
+        CxxPlatformInfo(name = "x86_64"),
+    ]
+
+cxx_toolchain = rule(
+    impl = _cxx_toolchain,
+    attrs = {
+        "link_style": attrs.string(default = "static"),
+        "make_comp_db": attrs.dep(providers = [RunInfo], default = DEFAULT_MAKE_COMP_DB),
+        "make_shlib_intf": attrs.dep(providers = [RunInfo], default = DEFAULT_MAKE_COMP_DB),
+    },
+    is_toolchain_rule = True,
+)
+
+def _python_bootstrap_toolchain(_ctx):
+    return [
+        DefaultInfo(),
+        PythonBootstrapToolchainInfo(
+            interpreter = "python3",
+        ),
+    ]
+
+python_bootstrap_toolchain = rule(
+    impl = _python_bootstrap_toolchain,
+    attrs = {},
+    is_toolchain_rule = True,
+)
+
+def _rust_toolchain(ctx):
+    return [
+        DefaultInfo(),
+        RustToolchainInfo(
+            allow_lints = [],
+            clippy_driver = "clippy-driver",
+            compiler = "rustc",
+            deny_lints = [],
+            rustc_action = ctx.attrs.rustc_action[RunInfo],
+            rustc_binary_flags = [],
+            rustc_check_flags = [],
+            rustc_flags = ["-Clink-arg=-fuse-ld=lld"],
+            rustc_target_triple = "x86_64-unknown-linux-gnu",
+            rustc_test_flags = [],
+            rustdoc = "rustdoc",
+            rustdoc_flags = [],
+            warn_lints = [],
+        ),
+        RustPlatformInfo(
+            name = "x86_64",
+        ),
+    ]
+
+rust_toolchain = rule(
+    impl = _rust_toolchain,
+    attrs = {
+        "rustc_action": attrs.dep(providers = [RunInfo], default = "prelude//rust/tools:rustc_action"),
+    },
+    is_toolchain_rule = True,
+)