sourceCpp() failed to compile if there is some space in R path

When there is some space in R path, sourceCpp failed to compile:

library(Rcpp)
code2 = "#include <Rcpp.h>\n\nusing namespace Rcpp;\n\n// [[Rcpp::export]]\nint fibonacci(const int x) {\n        if (x == 0) return(0);\n        if (x == 1) return(1);\n        return (fibonacci(x - 1)) + fibonacci(x - 2);\n    }"
sourceCpp(code = code2)

It showed the error:

Error in system(cmd, intern = !showOutput) : 'd:/Program' not found

> sessionInfo()
R version 4.2.1 (2022-06-23 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19044)

Matrix products: default

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] Rcpp_1.0.9

loaded via a namespace (and not attached):
[1] compiler_4.2.1 tools_4.2.1

A possible solution is to add the command r <- paste0('"', r, '"') after the command r <- paste(R.home("bin"), "R", sep = .Platform$file.sep).

After done that, it compiles normally.

> fibonacci(10)
[1] 55

Yes that line

Rcpp/R/Attributes.R

Line 132 in 8a44ae1

r <- paste(R.home("bin"), "R", sep = .Platform$file.sep)

is a little suspicious. We could use file.path() instead of paste and we use normalizePath in a number of other places already but not here:

edd@rob:~/git/rcpp(master)$ ag normalizePath
R/tools.R
43:        path <- normalizePath(path)                  # #nocov start

R/Attributes.R
39:    cacheDir <- normalizePath(cacheDir)
50:        rWorkingDir <- normalizePath(dirname(file))
54:    file <- normalizePath(file, winslash = "/")
238:    cppSourcePath <- normalizePath(cppSourcePath)
239:    buildDirectory <- normalizePath(buildDirectory)
245:    cacheFiles <- normalizePath(cacheFiles)
416:    pkgdir <- normalizePath(pkgdir, winslash = "/")
465:    cppFiles <- normalizePath(cppFiles, winslash = "/")

src/attributes.cpp
902:            Rcpp::Function normalizePath = baseEnv["normalizePath"];
942:                            include = normalizePath(include, "/");
984:            Rcpp::Function normalizePath = baseEnv["normalizePath"];
985:            sourceFile = Rcpp::as<std::string>(normalizePath(sourceFile, "/"));
edd@rob:~/git/rcpp(master)$

Can you also try the alternate form

r <- normalizePath(file.path(R.home("bin"), "R"), winslash = "/")

which should work (but I don't have a Windows system handy to test.

Can you also try the alternate form
r <- normalizePath(file.path(R.home("bin"), "R"), winslash = "/")
which should work (but I don't have a Windows system handy to test.

Thank you for the prompt response!
Yes, it worked, but there is a warning

> sourceCpp(code = code2)
Warning message:
In normalizePath(path.expand(path), winslash, mustWork) :
  path[1]="d:/Program Files/R/R-4.2.1/bin/x64/R": The system cannot find the file specified
> fibonacci(10)
[1] 55

Add ".exe" after "R" helps to get rid of the warning
r <- normalizePath(file.path(R.home("bin"), "R.exe"), winslash = "/"),
but of course it does not work on Linux or Mac.

Hence, maybe we should check the current OS like this?

if (.Platform$OS.type == "windows") {
  r <- normalizePath(file.path(R.home("bin"), "R.exe"))
}
else {
  r <- normalizePath(file.path(R.home("bin"), "R"))
}

Yes either that or maybe simpler to just add mustWork=FALSE to suppress the warning? (See ?normalizePath on that.)

Yes either than or maybe simpler to just add mustWork=FALSE to suppress the warning? (See ?normalizePath on that.)

Yes, it did, much simpler!

> sourceCpp(code = code2)
> fibonacci(10)
[1] 55

Splendid. I will get this taken care of. Thanks for the heads-up and the tests, much appreciated!