chore: fix Windows specific clippy errors (#15212)

2 files changed, 23 insertions, 16 deletions

diff --git a/ext/ffi/build.rs b/ext/ffi/build.rs
index 091dd9599..1debd6b9c 100644
--- a/ext/ffi/build.rs
+++ b/ext/ffi/build.rs
@@ -1,8 +1,9 @@
 // Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
 
-use std::env;
-
+#[cfg(not(target_os = "windows"))]
 fn build_tcc() {
+  use std::env;
+
   {
     // TODO(@littledivy): Windows support for fast call.
     // let tcc_path = root
@@ -58,6 +59,8 @@ fn main() {}
 
 #[cfg(not(target_os = "windows"))]
 fn main() {
+  use std::env;
+
   if let Ok(tcc_path) = env::var("TCC_PATH") {
     println!("cargo:rustc-link-search=native={}", tcc_path);
   } else {
diff --git a/ext/ffi/lib.rs b/ext/ffi/lib.rs
index 737ea9db2..ac792de44 100644
--- a/ext/ffi/lib.rs
+++ b/ext/ffi/lib.rs
@@ -518,8 +518,10 @@ pub(crate) fn format_error(e: dlopen::Error, path: String) -> String {
       let arguments = [path.as_ptr()];
 
       loop {
-        unsafe {
-          let length = FormatMessageW(
+        // SAFETY:
+        // winapi call to format the error message
+        let length = unsafe {
+          FormatMessageW(
             FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY,
             std::ptr::null_mut(),
             err_num as DWORD,
@@ -527,22 +529,24 @@ pub(crate) fn format_error(e: dlopen::Error, path: String) -> String {
             buf.as_mut_ptr(),
             buf.len() as DWORD,
             arguments.as_ptr() as _,
-          );
-
-          if length == 0 {
-            let err_num = GetLastError();
-            if err_num == ERROR_INSUFFICIENT_BUFFER {
-              buf.resize(buf.len() * 2, 0);
-              continue;
-            }
+          )
+        };
 
-            // Something went wrong, just return the original error.
-            return e.to_string();
+        if length == 0 {
+          // SAFETY:
+          // winapi call to get the last error message
+          let err_num = unsafe { GetLastError() };
+          if err_num == ERROR_INSUFFICIENT_BUFFER {
+            buf.resize(buf.len() * 2, 0);
+            continue;
           }
 
-          let msg = String::from_utf16_lossy(&buf[..length as usize]);
-          return msg;
+          // Something went wrong, just return the original error.
+          return e.to_string();
         }
+
+        let msg = String::from_utf16_lossy(&buf[..length as usize]);
+        return msg;
       }
     }
     _ => e.to_string(),