support riscv64 target

Signed-off-by: xermicus <cyrill@parity.io>

crates/builtins/Cargo.toml

@@ -4,6 +4,9 @@ version = "0.1.0"
 edition = "2021"
 build = "build.rs"
 
+[features]
+riscv-64 = []
+
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]

crates/builtins/build.rs

@@ -1,7 +1,11 @@
 use std::{env, fs, io::Read, path::Path, process::Command};
 
+#[cfg(not(feature = "riscv-64"))]
+pub const BUILTINS_ARCHIVE_FILE: &str = "libclang_rt.builtins-riscv32.a";
+#[cfg(feature = "riscv-64")]
+pub const BUILTINS_ARCHIVE_FILE: &str = "libclang_rt.builtins-riscv64.a";
+
 fn main() {
-    let lib = "libclang_rt.builtins-riscv32.a";
     let mut llvm_lib_dir = String::new();
 
     Command::new("llvm-config")
@@ -15,19 +19,22 @@ fn main() {
 
     let mut lib_path = std::path::PathBuf::from(llvm_lib_dir.trim())
         .join("linux")
-        .join(lib);
+        .join(BUILTINS_ARCHIVE_FILE);
     if !lib_path.exists() {
-        lib_path = std::path::PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap()).join(lib);
+        lib_path = std::path::PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap())
+            .join(BUILTINS_ARCHIVE_FILE);
     }
-    let archive = fs::read(lib_path).expect("clang builtins for riscv32 not found");
+    let archive = fs::read(lib_path).expect("clang builtins not found");
 
     let out_dir = env::var_os("OUT_DIR").expect("has OUT_DIR");
-    let archive_path = Path::new(&out_dir).join(lib);
+    let archive_path = Path::new(&out_dir).join(BUILTINS_ARCHIVE_FILE);
     let len = archive.len();
     std::fs::write(archive_path, &archive).expect("can write to OUT_DIR");
 
     let src_path = Path::new(&out_dir).join("compiler_rt.rs");
-    let src = format!("pub static COMPILER_RT: &[u8; {len}] = include_bytes!(\"{lib}\");");
+    let src = format!(
+        "pub static COMPILER_RT: &[u8; {len}] = include_bytes!(\"{BUILTINS_ARCHIVE_FILE}\");"
+    );
     fs::write(src_path, src).expect("can write to OUT_DIR");
 
     println!("cargo:rerun-if-changed=build.rs");