summaryrefslogtreecommitdiffstats
path: root/vendor/serde_derive/build.rs
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/serde_derive/build.rs')
-rw-r--r--vendor/serde_derive/build.rs36
1 files changed, 36 insertions, 0 deletions
diff --git a/vendor/serde_derive/build.rs b/vendor/serde_derive/build.rs
new file mode 100644
index 000000000..2aece0469
--- /dev/null
+++ b/vendor/serde_derive/build.rs
@@ -0,0 +1,36 @@
+use std::env;
+use std::process::Command;
+use std::str;
+
+// The rustc-cfg strings below are *not* public API. Please let us know by
+// opening a GitHub issue if your build environment requires some way to enable
+// these cfgs other than by executing our build script.
+fn main() {
+ let minor = match rustc_minor_version() {
+ Some(minor) => minor,
+ None => return,
+ };
+
+ // Underscore const names stabilized in Rust 1.37:
+ // https://blog.rust-lang.org/2019/08/15/Rust-1.37.0.html#using-unnamed-const-items-for-macros
+ if minor < 37 {
+ println!("cargo:rustc-cfg=no_underscore_consts");
+ }
+
+ // The ptr::addr_of! macro stabilized in Rust 1.51:
+ // https://blog.rust-lang.org/2021/03/25/Rust-1.51.0.html#stabilized-apis
+ if minor < 51 {
+ println!("cargo:rustc-cfg=no_ptr_addr_of");
+ }
+}
+
+fn rustc_minor_version() -> Option<u32> {
+ let rustc = env::var_os("RUSTC")?;
+ let output = Command::new(rustc).arg("--version").output().ok()?;
+ let version = str::from_utf8(&output.stdout).ok()?;
+ let mut pieces = version.split('.');
+ if pieces.next() != Some("rustc 1") {
+ return None;
+ }
+ pieces.next()?.parse().ok()
+}