build.rs: Improve conditional compilation around PerlAsm.

build.rs determines whether the target platform is supported by PerlAsm
using both target_arch and target_os. Instances of conditional
compilation in both src/ and crypto/ were using just target_arch to
determine whether PerlAsm symbols are present, resulting in link-time
build failures for certain targets, including, for example,
aarch64-unknown-none.

This commit fixes those instances of conditional compilation to align
with the build script.

I agree to license my contributions to each file under the terms given
at the top of each file I changed.

build.rs

@@ -259,13 +259,44 @@ const APPLE_ABI: &[&str] = &["ios", "macos", "tvos", "visionos", "watchos"];
 
 const WINDOWS: &str = "windows";
 
+fn get_target(is_git: bool) -> Target {
+    let arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
+    let os = env::var("CARGO_CFG_TARGET_OS").unwrap();
+    let env = env::var("CARGO_CFG_TARGET_ENV").unwrap();
+
+    // Published builds are always built in release mode.
+    let is_debug = is_git && env::var("DEBUG").unwrap() != "false";
+
+    // During local development, force warnings in non-Rust code to be treated
+    // as errors. Since warnings are highly compiler-dependent and compilers
+    // don't maintain backward compatibility w.r.t. which warnings they issue,
+    // don't do this for packaged builds.
+    let force_warnings_into_errors = is_git;
+
+    Target {
+        arch,
+        os,
+        env,
+        is_debug,
+        force_warnings_into_errors,
+    }
+}
+
+fn find_asm_target(target: &Target) -> Option<&'static AsmTarget> {
+    ASM_TARGETS.iter().find(|asm_target| {
+        asm_target.arch == target.arch && asm_target.oss.contains(&target.os.as_ref())
+    })
+}
+
 fn main() {
     // Avoid assuming the working directory is the same is the $CARGO_MANIFEST_DIR so that toolchains
     // which may assume other working directories can still build this code.
     let c_root_dir = PathBuf::from(
         env::var_os("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR should always be set"),
     );
 
+    let is_git = std::fs::metadata(c_root_dir.join(".git")).is_ok();
+
     // Keep in sync with `core_name_and_version!` in prefixed.rs.
     let core_name_and_version = [
         &env::var("CARGO_PKG_NAME").unwrap(),
@@ -282,48 +313,33 @@ fn main() {
         &core_name_and_version
     );
 
+    println!("cargo:rustc-check-cfg=cfg(perlasm)");
+    println!("cargo:rustc-check-cfg=cfg(no_perlasm)");
+
+    match find_asm_target(&get_target(is_git)) {
+        Some(_) => println!("cargo:rustc-cfg=perlasm"),
+        None => println!("cargo:rustc-cfg=no_perlasm"),
+    }
+
     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),
+        None => ring_build_rs_main(&c_root_dir, &core_name_and_version, is_git),
         _ => {
             panic!("${} has an invalid value", RING_PREGENERATE_ASM);
         }
     }
 }
 
-fn ring_build_rs_main(c_root_dir: &Path, core_name_and_version: &str) {
+fn ring_build_rs_main(c_root_dir: &Path, core_name_and_version: &str, is_git: bool) {
     let out_dir = env::var_os("OUT_DIR").unwrap();
     let out_dir = PathBuf::from(out_dir);
 
-    let arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
-    let os = env::var("CARGO_CFG_TARGET_OS").unwrap();
-    let env = env::var("CARGO_CFG_TARGET_ENV").unwrap();
-
-    let is_git = fs::metadata(c_root_dir.join(".git")).is_ok();
-
-    // Published builds are always built in release mode.
-    let is_debug = is_git && env::var("DEBUG").unwrap() != "false";
-
-    // During local development, force warnings in non-Rust code to be treated
-    // as errors. Since warnings are highly compiler-dependent and compilers
-    // don't maintain backward compatibility w.r.t. which warnings they issue,
-    // don't do this for packaged builds.
-    let force_warnings_into_errors = is_git;
-
-    let target = Target {
-        arch,
-        os,
-        env,
-        is_debug,
-        force_warnings_into_errors,
-    };
+    let target = get_target(is_git);
 
-    let asm_target = ASM_TARGETS.iter().find(|asm_target| {
-        asm_target.arch == target.arch && asm_target.oss.contains(&target.os.as_ref())
-    });
+    let asm_target = find_asm_target(&target);
 
     // If `.git` exists then assume this is the "local hacking" case where
     // we want to make it easy to build *ring* using `cargo build`/`cargo test`
@@ -586,6 +602,10 @@ fn configure_cc(c: &mut cc::Build, target: &Target, c_root_dir: &Path, include_d
     if target.force_warnings_into_errors {
         c.warnings_into_errors(true);
     }
+
+    if find_asm_target(target).is_none() {
+        let _ = c.define("OPENSSL_NO_ASM", "1");
+    }
 }
 
 fn nasm(file: &Path, arch: &str, include_dir: &Path, out_dir: &Path, c_root_dir: &Path) {

crypto/fipsmodule/ec/p256_shared.h

@@ -24,7 +24,6 @@
 #include "../bn/internal.h"
 
 #if !defined(OPENSSL_NO_ASM) && \
-    (defined(OPENSSL_X86_64) || defined(OPENSSL_AARCH64)) && \
     !defined(OPENSSL_SMALL)
 # define OPENSSL_USE_NISTZ256
 #endif

src/aead/aes.rs

@@ -32,7 +32,7 @@ pub(super) mod hw;
 pub(super) mod vp;
 
 cfg_if! {
-    if #[cfg(any(target_arch = "aarch64", target_arch = "x86_64"))] {
+    if #[cfg(all(perlasm, any(target_arch = "aarch64", target_arch = "x86_64")))] {
         pub(super) use ffi::AES_KEY;
     } else {
         use ffi::AES_KEY;
@@ -41,14 +41,20 @@ cfg_if! {
 
 #[derive(Clone)]
 pub(super) enum Key {
-    #[cfg(any(target_arch = "aarch64", target_arch = "x86_64", target_arch = "x86"))]
+    #[cfg(all(
+        perlasm,
+        any(target_arch = "aarch64", target_arch = "x86_64", target_arch = "x86")
+    ))]
     Hw(hw::Key),
 
-    #[cfg(any(
-        target_arch = "aarch64",
-        target_arch = "arm",
-        target_arch = "x86",
-        target_arch = "x86_64"
+    #[cfg(all(
+        perlasm,
+        any(
+            target_arch = "aarch64",
+            target_arch = "arm",
+            target_arch = "x86",
+            target_arch = "x86_64"
+        )
     ))]
     Vp(vp::Key),
 
@@ -61,16 +67,22 @@ impl Key {
         bytes: KeyBytes<'_>,
         cpu_features: cpu::Features,
     ) -> Result<Self, error::Unspecified> {
-        #[cfg(any(target_arch = "aarch64", target_arch = "x86", target_arch = "x86_64"))]
+        #[cfg(all(
+            perlasm,
+            any(target_arch = "aarch64", target_arch = "x86", target_arch = "x86_64")
+        ))]
         if let Some(hw_features) = cpu_features.get_feature() {
             return Ok(Self::Hw(hw::Key::new(bytes, hw_features)?));
         }
 
-        #[cfg(any(
-            target_arch = "aarch64",
-            target_arch = "arm",
-            target_arch = "x86_64",
-            target_arch = "x86"
+        #[cfg(all(
+            perlasm,
+            any(
+                target_arch = "aarch64",
+                target_arch = "arm",
+                target_arch = "x86_64",
+                target_arch = "x86"
+            )
         ))]
         if let Some(vp_features) = cpu_features.get_feature() {
             return Ok(Self::Vp(vp::Key::new(bytes, vp_features)?));
@@ -84,14 +96,20 @@ impl Key {
     #[inline]
     fn encrypt_block(&self, a: Block) -> Block {
         match self {
-            #[cfg(any(target_arch = "aarch64", target_arch = "x86_64", target_arch = "x86"))]
+            #[cfg(all(
+                perlasm,
+                any(target_arch = "aarch64", target_arch = "x86_64", target_arch = "x86")
+            ))]
             Key::Hw(inner) => inner.encrypt_block(a),
 
-            #[cfg(any(
-                target_arch = "aarch64",
-                target_arch = "arm",
-                target_arch = "x86",
-                target_arch = "x86_64"
+            #[cfg(all(
+                perlasm,
+                any(
+                    target_arch = "aarch64",
+                    target_arch = "arm",
+                    target_arch = "x86",
+                    target_arch = "x86_64"
+                )
             ))]
             Key::Vp(inner) => inner.encrypt_block(a),
 

src/aead/aes/hw.rs

@@ -12,7 +12,10 @@
 // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-#![cfg(any(target_arch = "aarch64", target_arch = "x86", target_arch = "x86_64"))]
+#![cfg(all(
+    perlasm,
+    any(target_arch = "aarch64", target_arch = "x86", target_arch = "x86_64")
+))]
 
 use super::{Block, Counter, EncryptBlock, EncryptCtr32, Iv, KeyBytes, AES_KEY};
 use crate::{cpu, error};

src/aead/aes/vp.rs

@@ -12,11 +12,14 @@
 // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-#![cfg(any(
-    target_arch = "aarch64",
-    target_arch = "arm",
-    target_arch = "x86",
-    target_arch = "x86_64"
+#![cfg(all(
+    perlasm,
+    any(
+        target_arch = "aarch64",
+        target_arch = "arm",
+        target_arch = "x86",
+        target_arch = "x86_64"
+    )
 ))]
 
 use super::{Block, Counter, EncryptBlock, EncryptCtr32, Iv, KeyBytes, AES_KEY};