Merging upstream version 1.70.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 46 insertions, 47 deletions

diff --git a/vendor/io-lifetimes/build.rs b/vendor/io-lifetimes/build.rs
index fd3c6ccce..2fc2a3817 100644
--- a/vendor/io-lifetimes/build.rs
+++ b/vendor/io-lifetimes/build.rs
@@ -8,7 +8,7 @@ fn main() {
     }
 
     // Work around
-    // https://github.com/rust-lang/rust/issues/103306.
+    // <https://github.com/rust-lang/rust/issues/103306>.
     use_feature_or_nothing("wasi_ext");
 
     // Rust 1.56 and earlier don't support panic in const fn.
@@ -33,70 +33,72 @@ fn use_feature(feature: &str) {
 
 /// Test whether the rustc at `var("RUSTC")` supports the given feature.
 fn has_feature(feature: &str) -> bool {
+    can_compile(format!(
+        "#![allow(stable_features)]\n#![feature({})]",
+        feature
+    ))
+}
+
+/// Test whether the rustc at `var("RUSTC")` can compile the given code.
+fn can_compile<T: AsRef<str>>(test: T) -> bool {
+    use std::process::Stdio;
+
     let out_dir = var("OUT_DIR").unwrap();
     let rustc = var("RUSTC").unwrap();
     let target = var("TARGET").unwrap();
 
-    let mut child = std::process::Command::new(rustc)
-        .arg("--crate-type=rlib") // Don't require `main`.
+    // Use `RUSTC_WRAPPER` if it's set, unless it's set to an empty string,
+    // as documented [here].
+    // [here]: https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-reads
+    let wrapper = var("RUSTC_WRAPPER")
+        .ok()
+        .and_then(|w| if w.is_empty() { None } else { Some(w) });
+
+    let mut cmd = if let Some(wrapper) = wrapper {
+        let mut cmd = std::process::Command::new(wrapper);
+        // The wrapper's first argument is supposed to be the path to rustc.
+        cmd.arg(rustc);
+        cmd
+    } else {
+        std::process::Command::new(rustc)
+    };
+
+    cmd.arg("--crate-type=rlib") // Don't require `main`.
         .arg("--emit=metadata") // Do as little as possible but still parse.
         .arg("--target")
         .arg(target)
         .arg("--out-dir")
-        .arg(out_dir) // Put the output somewhere inconsequential.
+        .arg(out_dir); // Put the output somewhere inconsequential.
+
+    // If Cargo wants to set RUSTFLAGS, use that.
+    if let Ok(rustflags) = var("CARGO_ENCODED_RUSTFLAGS") {
+        if !rustflags.is_empty() {
+            for arg in rustflags.split('\x1f') {
+                cmd.arg(arg);
+            }
+        }
+    }
+
+    let mut child = cmd
         .arg("-") // Read from stdin.
-        .stdin(std::process::Stdio::piped()) // Stdin is a pipe.
+        .stdin(Stdio::piped()) // Stdin is a pipe.
+        .stderr(Stdio::null()) // Errors from feature detection aren't interesting and can be confusing.
         .spawn()
         .unwrap();
 
-    writeln!(child.stdin.take().unwrap(), "#![feature({})]", feature).unwrap();
+    writeln!(child.stdin.take().unwrap(), "{}", test.as_ref()).unwrap();
 
     child.wait().unwrap().success()
 }
 
 /// Test whether the rustc at `var("RUSTC")` supports panic in `const fn`.
 fn has_panic_in_const_fn() -> bool {
-    let out_dir = var("OUT_DIR").unwrap();
-    let rustc = var("RUSTC").unwrap();
-    let target = var("TARGET").unwrap();
-
-    let mut child = std::process::Command::new(rustc)
-        .arg("--crate-type=rlib") // Don't require `main`.
-        .arg("--emit=metadata") // Do as little as possible but still parse.
-        .arg("--target")
-        .arg(target)
-        .arg("--out-dir")
-        .arg(out_dir) // Put the output somewhere inconsequential.
-        .arg("-") // Read from stdin.
-        .stdin(std::process::Stdio::piped()) // Stdin is a pipe.
-        .spawn()
-        .unwrap();
-
-    writeln!(child.stdin.take().unwrap(), "const fn foo() {{ panic!() }}").unwrap();
-
-    child.wait().unwrap().success()
+    can_compile("const fn foo() {{ panic!() }}")
 }
 
 /// Test whether the rustc at `var("RUSTC")` supports the I/O safety feature.
 fn has_io_safety() -> bool {
-    let out_dir = var("OUT_DIR").unwrap();
-    let rustc = var("RUSTC").unwrap();
-    let target = var("TARGET").unwrap();
-
-    let mut child = std::process::Command::new(rustc)
-        .arg("--crate-type=rlib") // Don't require `main`.
-        .arg("--emit=metadata") // Do as little as possible but still parse.
-        .arg("--target")
-        .arg(target)
-        .arg("--out-dir")
-        .arg(out_dir) // Put the output somewhere inconsequential.
-        .arg("-") // Read from stdin.
-        .stdin(std::process::Stdio::piped()) // Stdin is a pipe.
-        .spawn()
-        .unwrap();
-
-    writeln!(
-        child.stdin.take().unwrap(),
+    can_compile(
         "\
     #[cfg(unix)]\n\
     use std::os::unix::io::OwnedFd as Owned;\n\
@@ -106,9 +108,6 @@ fn has_io_safety() -> bool {
     use std::os::windows::io::OwnedHandle as Owned;\n\
     \n\
     pub type Success = Owned;\n\
-    "
+    ",
     )
-    .unwrap();
-
-    child.wait().unwrap().success()
 }