new extension= argument for cpp_register()

DESCRIPTION

@@ -59,5 +59,5 @@ Config/Needs/cpp11/cpp_register:
     vctrs
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.2.1
+RoxygenNote: 7.2.2
 SystemRequirements: C++11

NEWS.md

@@ -3,6 +3,9 @@
 * Silenced an unknown attribute warning specific to the Intel compiler
   (r-lib/systemfonts#98).
 
+* `cpp_register()` gains an argument `extension=` governing the file extension of
+  the `src/cpp11` file. By default it's `.cpp`, but `.cc` is now supported as well (#292, @MichaelChirico)
+
 # cpp11 0.4.3
 
 * Modernized the GitHub Actions workflows and updated some internal tests to

R/register.R

@@ -11,6 +11,8 @@
 #' `tibble` and `vctrs` packages must also be installed.
 #' @param path The path to the package root directory
 #' @param quiet If `TRUE` suppresses output from this function
+#' @param extension The file extension to use for the generated src/cpp11 file.
+#'   `.cpp` by default, but `.cc` is also supported.
 #' @return The paths to the generated R and C++ source files (in that order).
 #' @export
 #' @examples
@@ -34,11 +36,12 @@
 #'
 #' # cleanup
 #' unlink(dir, recursive = TRUE)
-cpp_register <- function(path = ".", quiet = !is_interactive()) {
+cpp_register <- function(path = ".", quiet = !is_interactive(), extension = c(".cpp", ".cc")) {
   stop_unless_installed(get_cpp_register_needs())
+  extension <- match.arg(extension)
 
   r_path <- file.path(path, "R", "cpp11.R")
-  cpp_path <- file.path(path, "src", "cpp11.cpp")
+  cpp_path <- file.path(path, "src", paste0("cpp11", extension))
   unlink(c(r_path, cpp_path))
 
   suppressWarnings(

tests/testthat/test-register.R

@@ -714,6 +714,16 @@ extern \"C\" attribute_visible void R_init_testPkg(DllInfo* dll){
 
     expect_error_free(cpp_register(p))
   })
+
+  it("accepts .cc as an alternative value for extension=", {
+    pkg <- local_package()
+    p <- pkg_path(pkg)
+    dir.create(file.path(p, "src"))
+    file.copy(test_path("single.cpp"), file.path(p, "src", "single.cc"))
+    cpp_register(p, extension = ".cc")
+
+    expect_match(list.files(file.path(p, "src")), "\\.cc$")
+  })
 })
 
 describe("generate_init_functions", {