Update windows compiler usage

R/install.R

@@ -846,8 +846,12 @@ toolchain_PATH_env_var <- function() {
 }
 
 rtools4x_toolchain_path <- function() {
-  c_runtime <- ifelse(is_ucrt_toolchain(), "ucrt64", "mingw64")
-  repair_path(file.path(rtools4x_home_path(), c_runtime, "bin"))
+  if (rtools4x_version() == "40") {
+    toolchain_folder <- "mingw64"
+  } else {
+    toolchain_folder <- "x86_64-w64-mingw32.static.posix"
+  }
+  repair_path(file.path(rtools4x_home_path(), toolchain_folder, "bin"))
 }
 
 rtools4x_version <- function() {

R/model.R

@@ -662,6 +662,7 @@ compile <- function(quiet = TRUE,
                 cpp_options_to_compile_flags(c(cpp_options, list("KEEP_OBJECT"="true"))),
                 stancflags_val),
         wd = cmdstan_path(),
+        env = c("current", "CXXFLAGS"="-fPIC"),
         echo = !quiet || is_verbose_mode(),
         echo_cmd = is_verbose_mode(),
         spinner = quiet && rlang::is_interactive() && !identical(Sys.getenv("IN_PKGDOWN"), "true"),

R/utils.R

@@ -86,7 +86,14 @@ is_rosetta2 <- function() {
 # Returns the type of make command to use to compile depending on the OS
 make_cmd <- function() {
   if (os_is_windows() && !os_is_wsl()) {
-    "mingw32-make.exe"
+    if (R.version$major == "3") {
+      make_folder <- file.path(Sys.getenv("RTOOLS35_HOME"), "mingw_64", "bin")
+    } else if (rtools4x_version() == "40") {
+      make_folder <- file.path(rtools4x_home_path(), "mingw64", "bin")
+    } else {
+      make_folder <- file.path(rtools4x_home_path(), "ucrt64", "bin")
+    }
+    repair_path(file.path(make_folder, "mingw32-make.exe"))
   } else {
     "make"
   }