Vendor things

third-party/vendor/backtrace/build.rs

@@ -0,0 +1,49 @@
+extern crate cc;
+
+use std::env;
+use std::path::Path;
+
+// Must be public so the build script of `std` can call it.
+pub fn main() {
+    match env::var("CARGO_CFG_TARGET_OS").unwrap_or_default().as_str() {
+        "android" => build_android(),
+        _ => {}
+    }
+}
+
+fn build_android() {
+    // Resolve `src/android-api.c` relative to this file.
+    // Required to support calling this from the `std` build script.
+    let android_api_c = Path::new(file!())
+        .parent()
+        .unwrap()
+        .join("src/android-api.c");
+    let expansion = match cc::Build::new().file(android_api_c).try_expand() {
+        Ok(result) => result,
+        Err(e) => {
+            println!("failed to run C compiler: {}", e);
+            return;
+        }
+    };
+    let expansion = match std::str::from_utf8(&expansion) {
+        Ok(s) => s,
+        Err(_) => return,
+    };
+    println!("expanded android version detection:\n{}", expansion);
+    let marker = "APIVERSION";
+    let i = match expansion.find(marker) {
+        Some(i) => i,
+        None => return,
+    };
+    let version = match expansion[i + marker.len() + 1..].split_whitespace().next() {
+        Some(s) => s,
+        None => return,
+    };
+    let version = match version.parse::<u32>() {
+        Ok(n) => n,
+        Err(_) => return,
+    };
+    if version >= 21 {
+        println!("cargo:rustc-cfg=feature=\"dl_iterate_phdr\"");
+    }
+}