1 files changed, 20 insertions, 8 deletions

diff --git a/libc/build.rs b/libc/build.rs
index 8452940..efc95b6 100644
--- a/libc/build.rs
+++ b/libc/build.rs
@@ -5,21 +5,27 @@ use std::str;
 fn main() {
     let rustc_minor_ver =
         rustc_minor_version().expect("Failed to get rustc version");
-    let rustc_dep_of_std =
-        std::env::var("CARGO_FEATURE_RUSTC_DEP_OF_STD").is_ok();
-    let align_cargo_feature = std::env::var("CARGO_FEATURE_ALIGN").is_ok();
+    let rustc_dep_of_std = env::var("CARGO_FEATURE_RUSTC_DEP_OF_STD").is_ok();
+    let align_cargo_feature = env::var("CARGO_FEATURE_ALIGN").is_ok();
+    #[allow(unused)]
+    let libc_ci = env::var("LIBC_CI").is_ok();
 
-    if std::env::var("CARGO_FEATURE_USE_STD").is_ok() {
+    if env::var("CARGO_FEATURE_USE_STD").is_ok() {
         println!(
             "cargo:warning=\"libc's use_std cargo feature is deprecated since libc 0.2.55; \
              please consider using the `std` cargo feature instead\""
         );
     }
 
-    if std::env::var("LIBC_CI").is_ok() {
-        if let Some(12) = which_freebsd() {
-            println!("cargo:rustc-cfg=freebsd12");
-        }
+    // The ABI of libc is backward compatible with FreeBSD 11.
+    //
+    // On CI, we detect the actual FreeBSD version and match its ABI exactly,
+    // running tests to ensure that the ABI is correct.
+    match which_freebsd() {
+        Some(11) if libc_ci => println!("cargo:rustc-cfg=freebsd11"),
+        Some(12) if libc_ci => println!("cargo:rustc-cfg=freebsd12"),
+        Some(13) if libc_ci => println!("cargo:rustc-cfg=freebsd13"),
+        Some(_) | None => println!("cargo:rustc-cfg=freebsd11"),
     }
 
     // Rust >= 1.15 supports private module use:
@@ -53,6 +59,11 @@ fn main() {
     if rustc_minor_ver >= 33 || rustc_dep_of_std {
         println!("cargo:rustc-cfg=libc_packedN");
     }
+
+    // #[thread_local] is currently unstable
+    if rustc_dep_of_std {
+        println!("cargo:rustc-cfg=libc_thread_local");
+    }
 }
 
 fn rustc_minor_version() -> Option<u32> {
@@ -96,6 +107,7 @@ fn which_freebsd() -> Option<i32> {
     match &stdout {
         s if s.starts_with("11") => Some(11),
         s if s.starts_with("12") => Some(12),
+        s if s.starts_with("13") => Some(13),
         _ => None,
     }
 }