0004-Downstream-only-never-use-pre-generated-object-files.patch

--- a/vendor/ring-0.17.9/build.rs
+++ b/vendor/ring-0.17.9/build.rs
@@ -121,8 +121,6 @@
 
 const RING_TEST_SRCS: &[&str] = &[("crypto/constant_time_test.c")];
 
-const PREGENERATED: &str = "pregenerated";
-
 fn cpp_flags(compiler: &cc::Tool) -> &'static [&'static str] {
     if !compiler.is_like_msvc() {
         static NON_MSVC_FLAGS: &[&str] = &[
@@ -287,16 +285,7 @@
         &core_name_and_version
     );
 
-    const RING_PREGENERATE_ASM: &str = "RING_PREGENERATE_ASM";
-    match env::var_os(RING_PREGENERATE_ASM).as_deref() {
-        Some(s) if s == "1" => {
-            pregenerate_asm_main(&c_root_dir, &core_name_and_version);
-        }
-        None => ring_build_rs_main(&c_root_dir, &core_name_and_version),
-        _ => {
-            panic!("${} has an invalid value", RING_PREGENERATE_ASM);
-        }
-    }
+    ring_build_rs_main(&c_root_dir, &core_name_and_version)
 }
 
 fn ring_build_rs_main(c_root_dir: &Path, core_name_and_version: &str) {
@@ -344,9 +333,12 @@
     // If `.git` doesn't exist then assume that this is a packaged build where
     // we want to optimize for minimizing the build tools required: No Perl,
     // no nasm, etc.
-    let generated_dir = if !is_git {
-        c_root_dir.join(PREGENERATED)
-    } else {
+
+    // Downstream-only: we do not want to package or use pre-generated object
+    // files, even by rebuilding them ourselves rather than using the ones
+    // shipped in the crate.
+    // let use_pregenerated = !is_git;
+    let generated_dir = {
         generate_sources_and_preassemble(
             &out_dir,
             asm_target.into_iter(),
@@ -367,17 +359,6 @@
     emit_rerun_if_changed()
 }
 
-fn pregenerate_asm_main(c_root_dir: &Path, core_name_and_version: &str) {
-    let pregenerated = c_root_dir.join(PREGENERATED);
-    fs::create_dir(&pregenerated).unwrap();
-    generate_sources_and_preassemble(
-        &pregenerated,
-        ASM_TARGETS.iter(),
-        c_root_dir,
-        core_name_and_version,
-    );
-}
-
 fn generate_sources_and_preassemble<'a>(
     out_dir: &Path,
     asm_targets: impl Iterator<Item = &'a AsmTarget>,