CMake: Prefer LLVM 21

Author: kinke

cmake/Modules/FindLLVM.cmake

@@ -32,7 +32,8 @@
 # We also want an user-specified LLVM_ROOT_DIR to take precedence over the
 # system default locations such as /usr/local/bin. Executing find_program()
 # multiples times is the approach recommended in the docs.
-set(llvm_config_names llvm-config-20.1 llvm-config201 llvm-config-20
+set(llvm_config_names llvm-config-21.1 llvm-config211 llvm-config-21
+                      llvm-config-20.1 llvm-config201 llvm-config-20
                       llvm-config-19.1 llvm-config191 llvm-config-19
                       llvm-config-18.1 llvm-config181 llvm-config-18
                       llvm-config-17.0 llvm-config170 llvm-config-17
@@ -48,10 +49,12 @@ if(APPLE)
     # extra fallbacks for MacPorts & Homebrew
     find_program(LLVM_CONFIG
         NAMES ${llvm_config_names}
-        PATHS /opt/local/libexec/llvm-20/bin /opt/local/libexec/llvm-19/bin
+        PATHS /opt/local/libexec/llvm-21/bin
+              /opt/local/libexec/llvm-20/bin /opt/local/libexec/llvm-19/bin
               /opt/local/libexec/llvm-18/bin /opt/local/libexec/llvm-17/bin
               /opt/local/libexec/llvm-16/bin /opt/local/libexec/llvm-15/bin
               /opt/local/libexec/llvm/bin
+              /usr/local/opt/llvm@21/bin
               /usr/local/opt/llvm@20/bin /usr/local/opt/llvm@19/bin
               /usr/local/opt/llvm@18/bin /usr/local/opt/llvm@17/bin
               /usr/local/opt/llvm@16/bin /usr/local/opt/llvm@15/bin