Support win arm64 in rust source

R/source.R

@@ -278,65 +278,7 @@ rust_source <- function(
 
   # append rtools path to the end of PATH on Windows
   if (opts[["use_rtools"]] && .Platform$OS.type == "windows") {
-    if (!suppressMessages(pkgbuild::has_rtools())) {
-      cli::cli_abort(
-        c(
-          "Unable to find Rtools that are needed for compilation.",
-          "i" = "Required version is {.emph {pkgbuild::rtools_needed()}}."
-        ),
-        class = "rextendr_error"
-      )
-    }
-
-    if (identical(R.version$crt, "ucrt")) {
-      # TODO: update this when R 5.0 is released.
-      if (!identical(R.version$major, "4")) {
-        cli::cli_abort(
-          "rextendr currently supports R 4.2",
-          call = rlang::caller_call(),
-          class = "rextendr_error"
-        )
-      }
-
-      minor_patch <- package_version(R.version$minor)
-
-      if (minor_patch >= "5.0") {
-        rtools_version <- "45" # nolint: object_usage_linter
-      } else if (minor_patch >= "4.0") {
-        rtools_version <- "44" # nolint: object_usage_linter
-      } else if (minor_patch >= "3.0") {
-        rtools_version <- "43" # nolint: object_usage_linter
-      } else {
-        rtools_version <- "42" # nolint: object_usage_linter
-      }
-
-      rtools_home <- normalizePath(
-        Sys.getenv(
-          glue("RTOOLS{rtools_version}_HOME"),
-          glue("C:\\rtools{rtools_version}")
-        ),
-        mustWork = TRUE
-      )
-
-      # c.f. https://github.com/wch/r-source/blob/f09d3d7fa4af446ad59a375d914a0daf3ffc4372/src/library/profile/Rprofile.windows#L70-L71 # nolint: line_length_linter
-      subdir <- c("x86_64-w64-mingw32.static.posix", "usr")
-    } else {
-      # rtools_path() returns path to the RTOOLS40_HOME\usr\bin,
-      # but we need RTOOLS40_HOME\mingw{arch}\bin, hence the "../.."
-      rtools_home <- normalizePath(
-        # `pkgbuild` may return two paths for R < 4.2 with Rtools40v2
-        file.path(pkgbuild::rtools_path()[1], "..", ".."),
-        winslash = "/",
-        mustWork = TRUE
-      )
-
-      subdir <- paste0("mingw", ifelse(R.version$arch == "i386", "32", "64"))
-      # if RTOOLS40_HOME is properly set, this will have no real effect
-      withr::local_envvar(RTOOLS40_HOME = rtools_home)
-    }
-
-    rtools_bin_path <- normalizePath(file.path(rtools_home, subdir, "bin"))
-    withr::local_path(rtools_bin_path, action = "suffix")
+    use_rtools()
   }
 
   # get target name, not null for Windows
@@ -804,6 +746,10 @@ get_specific_target_name <- function() {
       return("i686-pc-windows-gnu")
     }
 
+    if (R.version$arch == "aarch64") {
+      return(NULL)
+    }
+
     cli::cli_abort(
       "Unknown Windows architecture",
       class = "rextendr_error"

R/use_rtools.R

@@ -0,0 +1,112 @@
+is_windows_arm <- function() {
+  proc_arch <- Sys.getenv("PROCESSOR_ARCHITECTURE")
+  r_arch <- R.version[["arch"]]
+
+  if (identical(proc_arch, "ARM64") && !identical(r_arch, "aarch64")) {
+    cli::cli_abort(
+      c(
+        "Architecture mismatch detected.",
+        "i" = "You are running the {.code {proc_arch}} version of Windows, but the {.code {r_arch}} version of R.",
+        "i" = "You can find ARM64 build of R at {.url https://www.r-project.org/nosvn/winutf8/aarch64}"
+      ),
+      class = "rextendr_error"
+    )
+  }
+
+  identical(proc_arch, "ARM64") && identical(r_arch, "aarch64")
+}
+
+throw_if_no_rtools <- function() {
+  if (!suppressMessages(pkgbuild::has_rtools())) {
+    cli::cli_abort(
+      c(
+        "Unable to find Rtools that are needed for compilation.",
+        "i" = "Required version is {.emph {pkgbuild::rtools_needed()}}."
+      ),
+      class = "rextendr_error"
+    )
+  }
+}
+
+throw_if_not_ucrt <- function() {
+  if (!identical(R.version$crt, "ucrt")) {
+    cli::cli_abort(
+      c(
+        "R must be built with UCRT to use rextendr.",
+        "i" = "Please install the UCRT version of R from {.url https://cran.r-project.org/}."
+      ),
+      class = "rextendr_error"
+    )
+  }
+}
+
+get_rtools_version <- function() {
+  minor_patch <- package_version(R.version$minor)
+
+  if (minor_patch >= "5.0") {
+    "45"
+  } else if (minor_patch >= "4.0") {
+    "44"
+  } else if (minor_patch >= "3.0") {
+    "43"
+  } else {
+    "42"
+  }
+}
+
+get_path_to_cargo_folder_arm <- function(rtools_root) {
+  path_to_cargo_folder <- file.path(rtools_root, "clangarm64", "bin")
+  path_to_cargo <- file.path(path_to_cargo_folder, "cargo.exe")
+  if (!file.exists(path_to_cargo)) {
+    cli::cli_abort(
+      c(
+        "{.code rextendr} on ARM Windows requires an ARM-compatible Rust toolchain.",
+        "i" = "Check this instructions to set up {.code cargo} using ARM version of RTools: {.url https://github.com/r-rust/faq?tab=readme-ov-file#does-rust-support-windows-on-arm64-aarch64}." # nolint: line_length_linter
+      ),
+      class = "rextendr_error"
+    )
+  }
+
+  normalizePath(path_to_cargo_folder, mustWork = TRUE)
+}
+
+use_rtools <- function(.local_envir = parent.frame()) {
+  throw_if_no_rtools()
+  throw_if_not_ucrt()
+
+  is_arm <- is_windows_arm()
+
+  rtools_version <- get_rtools_version()
+
+  env_var <- if (is_arm) {
+    sprintf("RTOOLS%s_AARCH64_HOME", rtools_version)
+  } else {
+    sprintf("RTOOLS%s_HOME", rtools_version)
+  }
+
+  default_path <- if (is_arm) {
+    sprintf("C:\\rtools%s-aarch64", rtools_version)
+  } else {
+    sprintf("C:\\rtools%s", rtools_version)
+  }
+
+  rtools_home <- normalizePath(
+    Sys.getenv(env_var, default_path),
+    mustWork = TRUE
+  )
+
+  # c.f. https://github.com/wch/r-source/blob/f09d3d7fa4af446ad59a375d914a0daf3ffc4372/src/library/profile/Rprofile.windows#L70-L71 # nolint: line_length_linter
+  subdir <- if (is_arm) {
+    c("aarch64-w64-mingw32.static.posix", "usr")
+  } else {
+    c("x86_64-w64-mingw32.static.posix", "usr")
+  }
+
+  rtools_bin_path <- normalizePath(file.path(rtools_home, subdir, "bin"))
+  withr::local_path(rtools_bin_path, action = "suffix", .local_envir = .local_envir)
+
+  if (is_arm) {
+    cargo_path <- get_path_to_cargo_folder_arm(rtools_home)
+    withr::local_path(cargo_path, .local_envir = .local_envir)
+  }
+}