Patch --extern arguments in phase_cargo_rustc as well

Author: hyd-dev

cargo-miri/bin.rs

@@ -565,7 +565,7 @@ fn phase_cargo_miri(mut args: env::Args) {
     exec(cmd)
 }
 
-fn phase_cargo_rustc(args: env::Args) {
+fn phase_cargo_rustc(mut args: env::Args) {
     /// Determines if we are being invoked (as rustc) to build a crate for
     /// the "target" architecture, in contrast to the "host" architecture.
     /// Host crates are for build scripts and proc macros and still need to
@@ -655,7 +655,7 @@ fn phase_cargo_rustc(args: env::Args) {
     if !print && target_crate {
         // Forward arguments, but remove "link" from "--emit" to make this a check-only build.
         let emit_flag = "--emit";
-        for arg in args {
+        while let Some(arg) = args.next() {
             if arg.starts_with(emit_flag) {
                 // Patch this argument. First, extract its value.
                 let val = &arg[emit_flag.len()..];
@@ -671,6 +671,10 @@ fn phase_cargo_rustc(args: env::Args) {
                     }
                 }
                 cmd.arg(format!("{}={}", emit_flag, val.join(",")));
+            } else if arg == "--extern" {
+                // Patch `--extern` filenames, since Cargo sometimes passes stub `.rlib` files:
+                // https://github.com/rust-lang/miri/issues/1705
+                forward_patched_extern_arg(&mut args, &mut cmd);
             } else {
                 cmd.arg(arg);
             }

test-cargo-miri/Cargo.lock

@@ -11,6 +11,7 @@ edition = "2018"
 byteorder = "1.0"
 issue_1567 = { path = "issue-1567" }
 issue_1691 = { path = "issue-1691" }
+issue_1705 = { path = "issue-1705" }
 
 [dev-dependencies]
 rand = { version = "0.7", features = ["small_rng"] }

test-cargo-miri/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "issue_1705"
+version = "0.1.0"
+authors = ["Miri Team"]
+edition = "2018"
+
+[lib]
+crate-type = ["lib", "staticlib", "cdylib"]
+
+[dependencies]
+byteorder = "1.0"

test-cargo-miri/issue-1705/Cargo.toml

@@ -0,0 +1,5 @@
+use byteorder::{LittleEndian, ByteOrder};
+
+pub fn use_the_dependency() {
+    let _n = <LittleEndian as ByteOrder>::read_u32(&[1,2,3,4]);
+}

test-cargo-miri/issue-1705/src/lib.rs

@@ -3,5 +3,6 @@
 /// assert!(cargo_miri_test::make_true());
 /// ```
 pub fn make_true() -> bool {
+    issue_1705::use_the_dependency();
     issue_1691::use_me()
 }