Support USE_PERL fallback for gensymbol

cmake/export.cmake

@@ -50,6 +50,7 @@ else()
   set(ONLY_CBLAS_IN ${ONLY_CBLAS})
 endif()
 
+if (NOT DEFINED USE_PERL)
 add_custom_command(
   OUTPUT ${PROJECT_BINARY_DIR}/openblas.def
   #TARGET ${OpenBLAS_LIBNAME} PRE_LINK
@@ -57,5 +58,13 @@ add_custom_command(
   ARGS "win2k" "${ARCH_IN}" "dummy" "${EXPRECISION_IN}" "${NO_CBLAS_IN}" "${NO_LAPACK_IN}" "${NO_LAPACKE_IN}" "${NEED2UNDERSCORES_IN}" "${ONLY_CBLAS_IN}" "${SYMBOLPREFIX}" "${SYMBOLSUFFIX}" > "${PROJECT_BINARY_DIR}/openblas.def"
   COMMENT "Create openblas.def file"
   VERBATIM)
-
+else
+add_custom_command(
+  OUTPUT ${PROJECT_BINARY_DIR}/openblas.def
+  #TARGET ${OpenBLAS_LIBNAME} PRE_LINK
+  COMMAND perl 
+  ARGS "${PROJECT_SOURCE_DIR}/exports/gensymbol" "win2k" "${ARCH_IN}" "dummy" "${EXPRECISION_IN}" "${NO_CBLAS_IN}" "${NO_LAPACK_IN}" "${NO_LAPACKE_IN}" "${NEED2UNDERSCORES_IN}" "${ONLY_CBLAS_IN}" "${SYMBOLPREFIX}" "${SYMBOLSUFFIX}" > "${PROJECT_BINARY_DIR}/openblas.def"
+  COMMENT "Create openblas.def file"
+  VERBATIM)
+endif()
 endif()