refine R build.

R-package/DESCRIPTION

 Package: lightgbm
 Type: Package
 Title: Light Gradient Boosting Machine
-Version: 0.2
-Date: 2017-06-05
+Version: 2.0.2
+Date: 2017-06-22
 Author: Guolin Ke <guolin.ke@microsoft.com>
 Maintainer: Guolin Ke <guolin.ke@microsoft.com>
 Description: LightGBM is a gradient boosting framework that uses tree based learning algorithms. 

R-package/build_package.R

-if (!file.copy("./../include", "src/", overwrite = TRUE, recursive = TRUE)) {
+unlink("./src/include", recursive = TRUE)
+unlink("./src/src", recursive = TRUE)
+unlink("./src/compute", recursive = TRUE)
+unlink("./src/build", recursive = TRUE)
+unlink("./src/Release", recursive = TRUE)
+if (!file.copy("./../include", "./src/", overwrite = TRUE, recursive = TRUE)) {
   stop("Cannot find folder LightGBM/include")
 }
-if (!file.copy("./../src", "src/", overwrite = TRUE, recursive = TRUE)) {
+if (!file.copy("./../src", "./src/", overwrite = TRUE, recursive = TRUE)) {
   stop("Cannot find folder LightGBM/src")
 }
-if (!file.copy("./../compute", "src/", overwrite = TRUE, recursive = TRUE)) {
+if (!file.copy("./../compute", "./src/", overwrite = TRUE, recursive = TRUE)) {
   print("Cannot find folder LightGBM/compute, will disable GPU build")
 }
-if (!file.copy("./../CMakeLists.txt", "src/", overwrite = TRUE, recursive = TRUE)) {
+if (!file.copy("./../CMakeLists.txt", "./src/", overwrite = TRUE, recursive = TRUE)) {
   stop("Cannot find file LightGBM/CMakeLists.txt")
 }
-if (!file.exists("src/_IS_FULL_PACKAGE")) {
-  file.create("src/_IS_FULL_PACKAGE")
+if (!file.exists("./src/_IS_FULL_PACKAGE")) {
+  file.create("./src/_IS_FULL_PACKAGE")
 }
 system("R CMD build --no-build-vignettes .")
+file.remove("./src/_IS_FULL_PACKAGE")

R-package/src/install.libs.R

@@ -3,6 +3,10 @@ use_precompile <- FALSE
 use_gpu <- FALSE
 use_mingw <- FALSE
 
+if (.Machine$sizeof.pointer != 8){
+  stop("Only support 64-bit R, please check your the version of your R and Rtools.")
+}
+
 # Check for precompilation
 if (!use_precompile) {
 
@@ -11,6 +15,10 @@ if (!use_precompile) {
   setwd(source_dir)
   
   if (!file.exists("_IS_FULL_PACKAGE")) {
+    unlink("./include", recursive = TRUE)
+    unlink("./src", recursive = TRUE)
+    unlink("./compute", recursive = TRUE)
+	unlink("./build", recursive = TRUE)
     if (!file.copy("./../../include", "./", overwrite = TRUE, recursive = TRUE)) {
       stop("Cannot find folder LightGBM/include")
     }
@@ -24,7 +32,7 @@ if (!use_precompile) {
       }
     }
     if (!file.copy("./../../CMakeLists.txt", "./", overwrite = TRUE, recursive = TRUE)) {
-  	  stop("Cannot find file LightGBM/CMakeLists.txt")
+      stop("Cannot find file LightGBM/CMakeLists.txt")
     }
   }