From 0669abda4aa2a544ad8ab465fba0853ff8379c23 Mon Sep 17 00:00:00 2001
From: Jay Somedon <jay.somedon@outlook.com>
Date: Thu, 24 Dec 2020 23:00:59 +0800
Subject: [PATCH] Revise error message regarding metadata version
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Co-authored-by: Laurențiu Nicola <lnicola@users.noreply.github.com>
---
 crates/proc_macro_api/src/lib.rs | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/crates/proc_macro_api/src/lib.rs b/crates/proc_macro_api/src/lib.rs
index 481fb6deead..8f0f141f719 100644
--- a/crates/proc_macro_api/src/lib.rs
+++ b/crates/proc_macro_api/src/lib.rs
@@ -76,10 +76,7 @@ pub fn extern_process(
         args: impl IntoIterator<Item = impl AsRef<OsStr>>,
     ) -> io::Result<ProcMacroClient> {
         let (thread, process) = ProcMacroProcessSrv::run(process_path, args)?;
-        Ok(ProcMacroClient {
-            process: Arc::new(process),
-            thread,
-        })
+        Ok(ProcMacroClient { process: Arc::new(process), thread })
     }
 
     pub fn by_dylib_path(&self, dylib_path: &Path) -> Vec<ProcMacro> {
@@ -106,11 +103,7 @@ pub fn by_dylib_path(&self, dylib_path: &Path) -> Vec<ProcMacro> {
                     dylib_path: dylib_path.into(),
                 });
 
-                ProcMacro {
-                    name,
-                    kind,
-                    expander,
-                }
+                ProcMacro { name, kind, expander }
             })
             .collect()
     }
@@ -156,7 +149,10 @@ fn read_version(&self, dylib_path: &Path) -> io::Result<String> {
         const EXPECTED_HEADER: [u8; 8] = [b'r', b'u', b's', b't', 0, 0, 0, 5];
         // check if header is valid
         if header != EXPECTED_HEADER {
-            return Err(io::Error::new(io::ErrorKind::InvalidData, format!(".rustc section should start with header {:?}; header {:?} is actually presented.",EXPECTED_HEADER ,header)));
+            return Err(io::Error::new(
+                io::ErrorKind::InvalidData,
+                format!("only metadata version 5 is supported, section header was: {:?}", header),
+            ));
         }
 
         let snappy_portion = &dot_rustc[8..];