Add cfg-if-1.0.0 and working process doc

Signed-off-by: Quanyi Ma <eli@patch.sh>

Author: genedna

BUCK

@@ -9,6 +9,7 @@ cargo.rust_binary(
         "//third-party/rust/crates/libc/0.2.169:libc",
         "//third-party/rust/crates/shlex/1.3.0:shlex",
         "//third-party/rust/crates/zstd-sys/2.0.13+zstd.1.5.6:zstd-sys",
+        "//third-party/rust/crates/cfg-if/1.0.0:cfg-if",
     ],
     visibility = ["PUBLIC"],
 )

third-party/README.md

@@ -1,2 +1,84 @@
+## Third-Party Crate Working Process
 
-"https://static.crates.io/crates/{crate}/{crate}-{version}.crate"
+### Download crate without cargo
+
+The crate URL is `https://static.crates.io/crates/{crate}/{crate}-{version}.crate`, download the crate using `wget` like this:
+
+```bash
+wget https://static.crates.io/crates/cfg-if/cfg-if-1.0.0.crate
+tar -xvf cfg-if-1.0.0.crate
+rm cfg-if-1.0.0.crate
+mv cfg-if-1.0.0 1.0.0
+pwd
+# buck2-rust-third-party/third-party/rust/crates/cfg-if/1.0.0
+```
+
+### Add Buck2 configs
+
+Copy `toolchains` folder and `.buckconfig` file from other crate into working directory:
+
+```
+cd 1.0.0
+mkdir toolchains
+cp -r ../../shlex/1.3.0/toolchains .
+cp ../../shlex/1.3.0/.buckconfig .
+```
+
+### Add crate to project as dependency
+
+Add `//third-party/rust/crates/cfg-if/1.0.0:cfg-if` to `deps` list:
+
+```
+load("@prelude//rust:cargo_package.bzl", "cargo")
+
+cargo.rust_binary(
+    name = "buck2-rust-third-party",
+    edition = "2021",
+    srcs = glob(["src/**/*.rs"]),
+    crate_root = "src/main.rs",
+    deps = [
+        "//third-party/rust/crates/libc/0.2.169:libc",
+        "//third-party/rust/crates/shlex/1.3.0:shlex",
+        "//third-party/rust/crates/zstd-sys/2.0.13+zstd.1.5.6:zstd-sys",
+        "//third-party/rust/crates/cfg-if/1.0.0:cfg-if",
+    ],
+    visibility = ["PUBLIC"],
+)
+```
+
+### Write BUCK for the crate
+
+```
+load("@prelude//rust:cargo_package.bzl", "cargo")
+
+cargo.rust_library(
+    name = "cfg-if",
+    srcs = glob(["**/*.rs"]),
+    edition = "2018",
+    visibility = ["PUBLIC"],
+    deps = [],
+)
+```
+
+### Clean the crate folder
+
+```
+cd ..
+rm -rf 1.0.0
+```
+
+### Clean the crate folder
+
+```
+cd ..
+rm -rf .github
+rm -rf .devcontainer
+```
+
+### Tips
+
+For now, I am trying to generate `BUCK` with `Cargo.toml` with Claude, and the promote words in Chinese:
+
+```
+
+```

third-party/TODO.md

@@ -0,0 +1,5 @@
+## TODO
+
+### Not Implemented
+
+[ ] cfg-if `rustc-dep-of-std = ["core", "compiler_builtins"]`

third-party/rust/crates/cfg-if/1.0.0/.buckconfig

@@ -0,0 +1,24 @@
+[cells]
+  root = .
+  prelude = prelude
+  toolchains = toolchains
+  none = none
+
+[cell_aliases]
+  config = prelude
+  ovr_config = prelude
+  fbcode = none
+  fbsource = none
+  fbcode_macros = none
+  buck = none
+
+# Uses a copy of the prelude bundled with the buck2 binary. You can alternatively delete this
+# section and vendor a copy of the prelude to the `prelude` directory of your project.
+[external_cells]
+  prelude = bundled
+
+[parser]
+  target_platform_detector_spec = target:root//...->prelude//platforms:default
+
+[build]
+  execution_platforms = prelude//platforms:default

third-party/rust/crates/cfg-if/1.0.0/.cargo_vcs_info.json

@@ -0,0 +1,5 @@
+{
+  "git": {
+    "sha1": "e60fa1efeab0ec6e90c50d93ec526e1410459c23"
+  }
+}

third-party/rust/crates/cfg-if/1.0.0/.gitignore

@@ -0,0 +1,2 @@
+target
+Cargo.lock

third-party/rust/crates/cfg-if/1.0.0/BUCK

@@ -0,0 +1,9 @@
+load("@prelude//rust:cargo_package.bzl", "cargo")
+
+cargo.rust_library(
+    name = "cfg-if",
+    srcs = glob(["**/*.rs"]),
+    edition = "2018",
+    visibility = ["PUBLIC"],
+    deps = [],
+)

third-party/rust/crates/cfg-if/1.0.0/Cargo.toml

@@ -0,0 +1,36 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies
+#
+# If you believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
+
+[package]
+edition = "2018"
+name = "cfg-if"
+version = "1.0.0"
+authors = ["Alex Crichton <alex@alexcrichton.com>"]
+description = "A macro to ergonomically define an item depending on a large number of #[cfg]\nparameters. Structured like an if-else chain, the first matching branch is the\nitem that gets emitted.\n"
+homepage = "https://github.com/alexcrichton/cfg-if"
+documentation = "https://docs.rs/cfg-if"
+readme = "README.md"
+license = "MIT/Apache-2.0"
+repository = "https://github.com/alexcrichton/cfg-if"
+[dependencies.compiler_builtins]
+version = "0.1.2"
+optional = true
+
+[dependencies.core]
+version = "1.0.0"
+optional = true
+package = "rustc-std-workspace-core"
+
+[features]
+rustc-dep-of-std = ["core", "compiler_builtins"]
+[badges.travis-ci]
+repository = "alexcrichton/cfg-if"