From 3a055546bebeee9e4e73c4a4533a7b73651ee94c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=8E=8B=E9=98=B3?= <657837019@qq.com>
Date: Tue, 9 Jun 2026 23:48:29 +0800
Subject: [PATCH] Add RISC-V target detection

---
 CMakeLists.txt                 |  7 +++++++
 cmake/Modules/TargetArch.cmake | 29 +++++++++++++++++++++--------
 cmake/config.h.in              |  2 ++
 cmake/test-arch.c              |  9 +++++++++
 4 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4d154e4c..d940b275 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -71,6 +71,13 @@ add_feature_info(NEON32 BASE64_WITH_NEON32 "add NEON32 codepath")
 cmake_dependent_option(BASE64_WITH_NEON64 "add NEON64 codepath" ON _TARGET_ARCH_arm64 OFF)
 add_feature_info(NEON64 BASE64_WITH_NEON64 "add NEON64 codepath")
 
+if (_TARGET_ARCH STREQUAL "riscv" OR _TARGET_ARCH STREQUAL "riscv64")
+    set(BASE64_TARGET_RISCV ON)
+else()
+    set(BASE64_TARGET_RISCV OFF)
+endif()
+add_feature_info(RISC-V BASE64_TARGET_RISCV "use the portable codec on RISC-V targets")
+
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin")
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin")
 
diff --git a/cmake/Modules/TargetArch.cmake b/cmake/Modules/TargetArch.cmake
index d5b0a50b..f2e3bd11 100644
--- a/cmake/Modules/TargetArch.cmake
+++ b/cmake/Modules/TargetArch.cmake
@@ -15,16 +15,29 @@ set(TARGET_ARCHITECTURE_TEST_FILE "${CMAKE_CURRENT_LIST_DIR}/../test-arch.c")
 
 function(detect_target_architecture OUTPUT_VARIABLE)
     message(STATUS "${CMAKE_CURRENT_LIST_DIR}")
-    try_compile(_IGNORED "${CMAKE_CURRENT_BINARY_DIR}"
-        "${TARGET_ARCHITECTURE_TEST_FILE}"
-        OUTPUT_VARIABLE _LOG
-    )
+    set(_TARGET_PROCESSOR "${CMAKE_SYSTEM_PROCESSOR}")
+    if (DEFINED CACHE{CMAKE_SYSTEM_PROCESSOR})
+        list(APPEND _TARGET_PROCESSOR "$CACHE{CMAKE_SYSTEM_PROCESSOR}")
+    endif()
+    string(TOLOWER "${_TARGET_PROCESSOR}" _TARGET_PROCESSOR)
+
+    if (_TARGET_PROCESSOR MATCHES "(^|;)(riscv64|rv64)")
+        set(_TARGET_ARCHITECTURE "riscv64")
+    elseif (_TARGET_PROCESSOR MATCHES "(^|;)(riscv32|rv32|riscv)")
+        set(_TARGET_ARCHITECTURE "riscv")
+    else()
+        try_compile(_IGNORED "${CMAKE_CURRENT_BINARY_DIR}"
+            "${TARGET_ARCHITECTURE_TEST_FILE}"
+            OUTPUT_VARIABLE _LOG
+        )
 
-    string(REGEX MATCH "##arch=([^#]+)##" _IGNORED "${_LOG}")
+        string(REGEX MATCH "##arch=([^#]+)##" _IGNORED "${_LOG}")
+        set(_TARGET_ARCHITECTURE "${CMAKE_MATCH_1}")
+    endif()
 
-    set(${OUTPUT_VARIABLE} "${CMAKE_MATCH_1}" PARENT_SCOPE)
-    set("${OUTPUT_VARIABLE}_${CMAKE_MATCH_1}" 1 PARENT_SCOPE)
-    if (CMAKE_MATCH_1 STREQUAL "unknown")
+    set(${OUTPUT_VARIABLE} "${_TARGET_ARCHITECTURE}" PARENT_SCOPE)
+    set("${OUTPUT_VARIABLE}_${_TARGET_ARCHITECTURE}" 1 PARENT_SCOPE)
+    if (_TARGET_ARCHITECTURE STREQUAL "unknown")
         message(WARNING "could not detect the target architecture.")
     endif()
 endfunction()
diff --git a/cmake/config.h.in b/cmake/config.h.in
index c7faa94b..c2b50af3 100644
--- a/cmake/config.h.in
+++ b/cmake/config.h.in
@@ -25,4 +25,6 @@
 #cmakedefine01 BASE64_WITH_NEON64
 #define HAVE_NEON64 BASE64_WITH_NEON64
 
+#cmakedefine01 BASE64_TARGET_RISCV
+
 #endif // BASE64_CONFIG_H
diff --git a/cmake/test-arch.c b/cmake/test-arch.c
index a62c1443..8065a435 100644
--- a/cmake/test-arch.c
+++ b/cmake/test-arch.c
@@ -21,6 +21,15 @@
     || defined(_M_ARM)
 #error ##arch=arm##
 
+// RISC-V 64-Bit
+#elif defined(__riscv) \
+    && __riscv_xlen == 64
+#error ##arch=riscv64##
+
+// RISC-V
+#elif defined(__riscv)
+#error ##arch=riscv##
+
 // x86 64-Bit
 #elif defined(__x86_64__) \
     || defined(_M_X64)