Merge #453: [node] Fix: Allow compilation for all target os/arch

2f36579 [node] Fix: Allow compilation for all target os/arch (志宇)

Pull request description:

  Previously, if the target os/arch had no match, `download_filename` method would not exist, leading to compilation error.

  Now, if the target os/arch has no match, and a download is required, we panic instead. This change allows the user can set `BITCOIND_EXE` to skip the download step (without a compile error on OSes where the binary is not hosted on `bitcoincore.org`).

  ### Rationale

  Bitcoin Core can be compiled for other OSes such as BSD and Android. It's just that these binaries are not hosted on [bitcoincore.org](bitcoincore.org). A compile error based on whether the binaries are hosted on that domain does not make sense.

  ### Testing

  I haven't tested this on OSX, Linux or Windows. I was hoping the CLI can cover some of these before I get my laptop replaced.

ACKs for top commit:
  jamillambert:
    ACK 2f36579
  tcharding:
    ACK 2f36579

Tree-SHA512: 430a06156f0a9da2ed34b323f90dc2f6f88720065d4bedfba4bb123df5c066b1d017d2c507231b2c2b818ac0de8c203b47a170cf0bb35a62618c6279effccb61

Author: tcharding

node/build.rs

@@ -19,26 +19,32 @@ mod download {
 
     include!("src/versions.rs");
 
-    #[cfg(all(target_os = "macos", target_arch = "x86_64"))]
     fn download_filename() -> String {
-        if cfg!(not(feature = "23_2")) {
-            format!("bitcoin-{}-osx64.tar.gz", &VERSION)
-        } else {
-            format!("bitcoin-{}-x86_64-apple-darwin.tar.gz", &VERSION)
+        if cfg!(all(target_os = "macos", target_arch = "x86_64")) {
+            if cfg!(not(feature = "23_2")) {
+                return format!("bitcoin-{}-osx64.tar.gz", &VERSION);
+            }
+            return format!("bitcoin-{}-x86_64-apple-darwin.tar.gz", &VERSION);
+        }
+
+        if cfg!(all(target_os = "macos", target_arch = "aarch64")) {
+            return format!("bitcoin-{}-arm64-apple-darwin.tar.gz", &VERSION);
         }
-    }
 
-    #[cfg(all(target_os = "macos", target_arch = "aarch64"))]
-    fn download_filename() -> String { format!("bitcoin-{}-arm64-apple-darwin.tar.gz", &VERSION) }
+        if cfg!(all(target_os = "linux", target_arch = "x86_64")) {
+            return format!("bitcoin-{}-x86_64-linux-gnu.tar.gz", &VERSION);
+        }
 
-    #[cfg(all(target_os = "linux", target_arch = "x86_64"))]
-    fn download_filename() -> String { format!("bitcoin-{}-x86_64-linux-gnu.tar.gz", &VERSION) }
+        if cfg!(all(target_os = "linux", target_arch = "aarch64")) {
+            return format!("bitcoin-{}-aarch64-linux-gnu.tar.gz", &VERSION);
+        }
 
-    #[cfg(all(target_os = "linux", target_arch = "aarch64"))]
-    fn download_filename() -> String { format!("bitcoin-{}-aarch64-linux-gnu.tar.gz", &VERSION) }
+        if cfg!(all(target_os = "windows", target_arch = "x86_64")) {
+            return format!("bitcoin-{}-win64.zip", &VERSION);
+        }
 
-    #[cfg(all(target_os = "windows", target_arch = "x86_64"))]
-    fn download_filename() -> String { format!("bitcoin-{}-win64.zip", &VERSION) }
+        panic!("No download file for this os/arch");
+    }
 
     #[allow(clippy::lines_filter_map_ok)] // clippy doesn't like the `lines` call below and the suggested fix is incorrect.
     fn get_expected_sha256(filename: &str) -> anyhow::Result<sha256::Hash> {
@@ -72,9 +78,6 @@ mod download {
         if std::env::var_os("BITCOIND_SKIP_DOWNLOAD").is_some() {
             return Ok(());
         }
-        let download_filename = download_filename();
-        println!("download_filename: {}", download_filename);
-        let expected_hash = get_expected_sha256(&download_filename)?;
         let out_dir = PathBuf::from(std::env::var_os("OUT_DIR").unwrap());
 
         let bitcoin_exe_home = download_dir(&out_dir);
@@ -90,6 +93,10 @@ mod download {
         }
 
         if !existing_filename.exists() {
+            let download_filename = download_filename();
+            println!("download_filename: {}", download_filename);
+            let expected_hash = get_expected_sha256(&download_filename)?;
+
             println!("filename:{} version:{} hash:{}", download_filename, VERSION, expected_hash);
 
             let (file_or_url, tarball_bytes) = match std::env::var("BITCOIND_TARBALL_FILE") {