From c05b3088b47fcdcf2a75fdc2bc3047556f8b961e Mon Sep 17 00:00:00 2001
From: Steffen Jaeckel <s@jaeckel.eu>
Date: Mon, 4 May 2026 10:03:16 +0200
Subject: [PATCH] Use `__has_attribute()` for `target` attribute.

... and bring aarch64/PMULL in similar shape as x86/PCLMUL.

Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>
---
 helper.pl                     |  1 +
 src/encauth/gcm/gcm_gf_mult.c |  5 ++++-
 src/headers/tomcrypt_cfg.h    | 23 +++++++++++++++--------
 src/misc/crypt/crypt.c        |  3 +++
 4 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/helper.pl b/helper.pl
index 8a8824a1..3dcafcaf 100755
--- a/helper.pl
+++ b/helper.pl
@@ -71,6 +71,7 @@ sub check_source {
         my $n = $1;
         push @{$troubles->{invalid_macro_name}}, "$lineno($n)"
                 unless ($file eq 'src/headers/tomcrypt_cfg.h' &&  $n eq '__has_builtin') ||
+                       ($file eq 'src/headers/tomcrypt_cfg.h' &&  $n eq '__has_attribute') ||
                        ($file eq 'src/headers/tomcrypt_cfg.h' &&  $n eq '_WIN32_WINNT') ||
                        ($file eq 'src/prngs/rng_get_bytes.c' &&  $n eq '_WIN32_WINNT');
       }
diff --git a/src/encauth/gcm/gcm_gf_mult.c b/src/encauth/gcm/gcm_gf_mult.c
index 778ce2da..0568d6ea 100644
--- a/src/encauth/gcm/gcm_gf_mult.c
+++ b/src/encauth/gcm/gcm_gf_mult.c
@@ -10,7 +10,7 @@
 #if defined(LTC_GCM_MODE) || defined(LTC_LRW_MODE)
 #if defined(LTC_GCM_PCLMUL)
 
-#define LTC_GCM_PCLMUL_TARGET LTC_ATTRIBUTE((__target__("pclmul,ssse3")))
+#define LTC_GCM_PCLMUL_TARGET LTC_TARGET("pclmul,ssse3")
 
 #if defined(__GNUC__)
 #pragma GCC diagnostic push
@@ -135,6 +135,9 @@ static void s_gcm_gf_mult_pclmul(const unsigned char *a, const unsigned char *b,
 #endif /* defined(LTC_GCM_PCLMUL) */
 
 #if defined(LTC_GCM_PMULL)
+
+#define LTC_GCM_PMULL_TARGET LTC_TARGET("+crypto")
+
 #if defined(__GNUC__)
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wbad-function-cast"
diff --git a/src/headers/tomcrypt_cfg.h b/src/headers/tomcrypt_cfg.h
index ebac5ac4..14b81d87 100644
--- a/src/headers/tomcrypt_cfg.h
+++ b/src/headers/tomcrypt_cfg.h
@@ -339,6 +339,14 @@ typedef unsigned long ltc_mp_digit;
    #endif
 #endif
 
+#if defined(__aarch64__) || defined(_M_ARM64)
+   #define LTC_ARCH_AARCH64
+   #if !defined(LTC_NO_GCM_PMULL)
+      #define LTC_GCM_PMULL
+      #undef LTC_GCM_TABLES
+   #endif
+#endif
+
 #if defined(__GNUC__)
    #define LTC_ALIGN_MSVC(n)
    #define LTC_ALIGN(n) __attribute__((aligned(n)))
@@ -395,21 +403,20 @@ typedef unsigned long ltc_mp_digit;
 #endif
 #endif
 
+#ifndef __has_attribute
+#  define __has_attribute(x) 0
+#endif
 #if defined(__GNUC__) || defined(__clang__)
 #  define LTC_ATTRIBUTE(x) __attribute__(x)
 #else
 #  define LTC_ATTRIBUTE(x)
 #endif
 
-#if !defined(LTC_NO_GCM_PMULL) && (defined(__aarch64__) || defined(_M_ARM64))
-#define LTC_GCM_PMULL
-#undef LTC_GCM_TABLES
+#if __has_attribute(target)
+#  define LTC_TARGET(x) LTC_ATTRIBUTE((target(x)))
 #endif
-
-#if defined(LTC_GCM_PMULL) && (defined(__clang__) || defined(__GNUC__))
-#define LTC_GCM_PMULL_TARGET __attribute__((target("+crypto")))
-#else
-#define LTC_GCM_PMULL_TARGET
+#ifndef LTC_TARGET
+#  define LTC_TARGET(x)
 #endif
 
 #endif /* TOMCRYPT_CFG_H */
diff --git a/src/misc/crypt/crypt.c b/src/misc/crypt/crypt.c
index d5583b22..a670d69b 100644
--- a/src/misc/crypt/crypt.c
+++ b/src/misc/crypt/crypt.c
@@ -438,6 +438,9 @@ const char *crypt_build_settings =
 #if defined(LTC_ARCH_X86)
    "    LTC_ARCH_X86\n"
 #endif
+#if defined(LTC_ARCH_AARCH64)
+   "    LTC_ARCH_AARCH64\n"
+#endif
 
     "\nVarious others: "
 #if defined(ARGTYPE)