Inform Cargo about build flags

Author: thomwiggers

pqcrypto-classicmceliece/build.rs

@@ -135,6 +135,7 @@ fn main() {
         build_avx2!("mceliece8192128f");
     }
 
+    println!("cargo::rustc-check-cfg=cfg(enable_x86_avx2)");
     if target_arch == "x86_64" && avx2_enabled && !is_windows {
         // Print enableing flag for AVX2 implementation
         println!("cargo:rustc-cfg=enable_x86_avx2");

pqcrypto-falcon/build.rs

@@ -158,10 +158,12 @@ fn main() {
         build_aarch64!("falcon-padded-1024");
     }
 
+    println!("cargo::rustc-check-cfg=cfg(enable_x86_avx2)");
     if target_arch == "x86_64" && avx2_enabled {
         // Print enableing flag for AVX2 implementation
         println!("cargo:rustc-cfg=enable_x86_avx2");
     }
+    println!("cargo::rustc-check-cfg=cfg(enable_aarch64_neon)");
     if target_arch == "aarch64" && neon_enabled {
         // Print enableing flag for AARCH64 implementation
         println!("cargo:rustc-cfg=enable_aarch64_neon");

pqcrypto-mldsa/build.rs

@@ -151,10 +151,12 @@ fn main() {
         build_aarch64!("ml-dsa-87");
     }
 
+    println!("cargo::rustc-check-cfg=cfg(enable_x86_avx2)");
     if target_arch == "x86_64" && avx2_enabled && !is_windows {
         // Print enableing flag for AVX2 implementation
         println!("cargo:rustc-cfg=enable_x86_avx2");
     }
+    println!("cargo::rustc-check-cfg=cfg(enable_aarch64_neon)");
     if target_arch == "aarch64" && neon_enabled {
         // Print enableing flag for AARCH64 implementation
         println!("cargo:rustc-cfg=enable_aarch64_neon");

pqcrypto-mlkem/build.rs

@@ -149,10 +149,12 @@ fn main() {
         build_aarch64!("ml-kem-1024");
     }
 
+    println!("cargo::rustc-check-cfg=cfg(enable_x86_avx2)");
     if target_arch == "x86_64" && avx2_enabled && !is_windows && !is_macos {
         // Print enableing flag for AVX2 implementation
         println!("cargo:rustc-cfg=enable_x86_avx2");
     }
+    println!("cargo::rustc-check-cfg=cfg(enable_aarch64_neon)");
     if target_arch == "aarch64" && neon_enabled {
         // Print enableing flag for AARCH64 implementation
         println!("cargo:rustc-cfg=enable_aarch64_neon");

pqcrypto-sphincsplus/build.rs

@@ -145,6 +145,7 @@ fn main() {
         build_avx2!("sphincs-sha2-256s-simple");
     }
 
+    println!("cargo::rustc-check-cfg=cfg(enable_x86_avx2)");
     if target_arch == "x86_64" && avx2_enabled {
         // Print enableing flag for AVX2 implementation
         println!("cargo:rustc-cfg=enable_x86_avx2");

pqcrypto-template/scheme/build.rs.j2

@@ -111,18 +111,21 @@ fn main() {
     {% endfor %}
 
     {% if globals.x86_avx2 %}
+    println!("cargo::rustc-check-cfg=cfg(enable_x86_avx2)");
     if {{ x86_avx2_guard }} {
         // Print enableing flag for AVX2 implementation
         println!("cargo:rustc-cfg=enable_x86_avx2");
     }
     {% endif %}
     {% if globals.x86_aes %}
+    println!("cargo::rustc-check-cfg=cfg(enable_x86_aes)");
     if {{ x86_aes_guard }} {
         // Print enableing flag for AES implementation
         println!("cargo:rustc-cfg=enable_x86_aes");
     }
     {% endif %}
     {% if globals.aarch64_neon %}
+    println!("cargo::rustc-check-cfg=cfg(enable_aarch64_neon)");
     if {{ aarch64_neon_guard }} {
         // Print enableing flag for AARCH64 implementation
         println!("cargo:rustc-cfg=enable_aarch64_neon");