FindMatlab: accommodate Matlab running under Rosetta

fixes #24312

1 files changed, 14 insertions, 13 deletions

diff --git a/Modules/FindMatlab.cmake b/Modules/FindMatlab.cmake
index 9459e749bb..8bb402cd0b 100644
--- a/Modules/FindMatlab.cmake
+++ b/Modules/FindMatlab.cmake
@@ -655,7 +655,7 @@ function(matlab_get_mex_suffix matlab_root mex_suffix)
   endif()
 
   # the program has been found?
-  if((NOT Matlab_MEXEXTENSIONS_PROG) OR (NOT EXISTS ${Matlab_MEXEXTENSIONS_PROG}))
+  if(NOT Matlab_MEXEXTENSIONS_PROG)
     if(MATLAB_FIND_DEBUG)
       message(WARNING "[MATLAB] Cannot found mexext program. Matlab root is ${matlab_root}")
     endif()
@@ -706,7 +706,6 @@ function(matlab_get_mex_suffix matlab_root mex_suffix)
     message(STATUS "[MATLAB] '${Matlab_MEXEXTENSIONS_PROG}' : determined extension '${_matlab_mex_extension}' and error string is '${_matlab_mex_extension_error}'")
   endif()
 
-  unset(Matlab_MEXEXTENSIONS_PROG CACHE)
   set(${mex_suffix} ${_matlab_mex_extension} PARENT_SCOPE)
 endfunction()
 
@@ -1747,12 +1746,24 @@ else()
   set(_matlab_64Build TRUE)
 endif()
 
+
+if(NOT DEFINED Matlab_MEX_EXTENSION)
+  set(_matlab_mex_extension "")
+  matlab_get_mex_suffix("${Matlab_ROOT_DIR}" _matlab_mex_extension)
+
+  # This variable goes to the cache.
+  set(Matlab_MEX_EXTENSION ${_matlab_mex_extension} CACHE STRING "Extensions for the mex targets (automatically given by Matlab)")
+  unset(_matlab_mex_extension)
+endif()
+
 if(APPLE)
   set(_matlab_bin_prefix "mac") # i should be for intel
   set(_matlab_bin_suffix_32bits "i")
-  if(CMAKE_SYSTEM_PROCESSOR STREQUAL "arm64")
+  if(CMAKE_SYSTEM_PROCESSOR STREQUAL "arm64" AND Matlab_MEX_EXTENSION MATCHES "a64$")
+    # native Apple Silicon Matlab
     set(_matlab_bin_suffix_64bits "a64")
   else()
+    # Intel Mac OR Apple Silicon using Rosetta for Matlab
     set(_matlab_bin_suffix_64bits "i64")
   endif()
 elseif(UNIX)
@@ -1796,16 +1807,6 @@ endif()
 unset(_matlab_64Build)
 
 
-if(NOT DEFINED Matlab_MEX_EXTENSION)
-  set(_matlab_mex_extension "")
-  matlab_get_mex_suffix("${Matlab_ROOT_DIR}" _matlab_mex_extension)
-
-  # This variable goes to the cache.
-  set(Matlab_MEX_EXTENSION ${_matlab_mex_extension} CACHE STRING "Extensions for the mex targets (automatically given by Matlab)")
-  unset(_matlab_mex_extension)
-endif()
-
-
 if(MATLAB_FIND_DEBUG)
   message(STATUS "[MATLAB] [DEBUG]_matlab_lib_prefix_for_search = ${_matlab_lib_prefix_for_search} | _matlab_lib_dir_for_search = ${_matlab_lib_dir_for_search}")
 endif()