std: always depend on backtrace, but only enable its features on demand

2 files changed, 4 insertions, 2 deletions

diff --git a/src/libstd/sys_common/backtrace.rs b/src/libstd/sys_common/backtrace.rs
index 1a78abf5086..52890668c35 100644
--- a/src/libstd/sys_common/backtrace.rs
+++ b/src/libstd/sys_common/backtrace.rs
@@ -7,7 +7,6 @@ use crate::io;
 use crate::borrow::Cow;
 use crate::io::prelude::*;
 use crate::path::{self, Path, PathBuf};
-use crate::sync::atomic::{self, Ordering};
 use crate::sys::mutex::Mutex;
 
 use backtrace::{BacktraceFmt, BytesOrWideString, PrintFmt};
@@ -34,6 +33,7 @@ pub fn lock() -> impl Drop {
 }
 
 /// Prints the current backtrace.
+#[cfg(feature = "backtrace_support")]
 pub fn print(w: &mut dyn Write, format: PrintFmt) -> io::Result<()> {
     // There are issues currently linking libbacktrace into tests, and in
     // general during libstd's own unit tests we're not testing this path. In
@@ -129,7 +129,10 @@ where
 
 // For now logging is turned off by default, and this function checks to see
 // whether the magical environment variable is present to see if it's turned on.
+#[cfg(feature = "backtrace_support")]
 pub fn log_enabled() -> Option<PrintFmt> {
+    use crate::sync::atomic::{self, Ordering};
+
     // Setting environment variables for Fuchsia components isn't a standard
     // or easily supported workflow. For now, always display backtraces.
     if cfg!(target_os = "fuchsia") {
diff --git a/src/libstd/sys_common/mod.rs b/src/libstd/sys_common/mod.rs
index 9190a3b0d5f..cba3eca5386 100644
--- a/src/libstd/sys_common/mod.rs
+++ b/src/libstd/sys_common/mod.rs
@@ -41,7 +41,6 @@ macro_rules! rtunwrap {
 
 pub mod alloc;
 pub mod at_exit_imp;
-#[cfg(feature = "backtrace")]
 pub mod backtrace;
 pub mod condvar;
 pub mod io;