[R] update build commands.

R-package/DESCRIPTION

 Package: lightgbm
 Type: Package
 Title: Light Gradient Boosting Machine
-Version: 2.0.2
-Date: 2017-06-22
+Version: 2.0.4
+Date: 2017-07-14
 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/README.md

@@ -14,8 +14,6 @@ Note: 32-bit R/Rtools is not supported.
 
 Installing [Rtools](https://cran.r-project.org/bin/windows/Rtools/) is mandatory, and only support the 64-bit version.
 
-[cmake](https://cmake.org/) must be version 3.8 or higher.
-
 The default compiler is Visual Studio (or [MS Build](https://www.visualstudio.com/downloads/#build-tools-for-visual-studio-2017)) in Windows, with an automatic fallback to Rtools or any [MinGW64](https://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win64/Personal%20Builds/mingw-builds/) (x86_64-posix-seh) available (this means if you have only Rtools and cmake, it will compile fine).
 
 To force the usage of Rtools / MinGW, you can set `use_mingw` to `TRUE` in `R-package/src/install.libs.R`.
@@ -44,7 +42,7 @@ Or build a self-contained R package which can be installed afterwards:
 git clone --recursive https://github.com/Microsoft/LightGBM
 cd LightGBM/R-package
 Rscript build_package.R
-R CMD INSTALL lightgbm_2.0.2.tar.gz --no-multiarch
+R CMD INSTALL lightgbm_2.0.4.tar.gz --no-multiarch
 ``` 
 
 Note: for the build with Visual Studio/MSBuild in Windows, you should use the Windows CMD or Powershell.

R-package/src/install.libs.R

@@ -25,12 +25,10 @@ if (!use_precompile) {
     if (!file.copy("./../../src", "./", overwrite = TRUE, recursive = TRUE)) {
       stop("Cannot find folder LightGBM/src")
     }
-    if (use_gpu) {
     if (!file.copy("./../../compute", "./", overwrite = TRUE, recursive = TRUE)) {
       print("Cannot find folder LightGBM/compute, disabling GPU build.")
       use_gpu <- FALSE
     }
-    }
     if (!file.copy("./../../CMakeLists.txt", "./", overwrite = TRUE, recursive = TRUE)) {
       stop("Cannot find file LightGBM/CMakeLists.txt")
     }
@@ -42,35 +40,46 @@ if (!use_precompile) {
   setwd(build_dir)
   
   # Prepare installation steps
-  cmake_base <- "cmake "
+  cmake_cmd <- "cmake "
   build_cmd <- "make _lightgbm -j"
   lib_folder <- file.path(R_PACKAGE_SOURCE, "src", fsep = "/")
   
+  if (use_gpu) {
+    cmake_cmd <- paste0(cmake_cmd, " -DUSE_GPU=ON ")
+  }
+
   # Check if Windows installation (for gcc vs Visual Studio)
   if (WINDOWS) {
     if (use_mingw) {
-      cmake_cmd <- paste0(cmake_base, " -G \"MinGW Makefiles\" ")
+      cmake_cmd <- paste0(cmake_cmd, " -G \"MinGW Makefiles\" ")
       build_cmd <- "mingw32-make.exe _lightgbm -j"
       system(paste0(cmake_cmd, " ..")) # Must build twice for Windows due sh.exe in Rtools
     } else {
-      cmake_cmd <- paste0(cmake_base, " -DCMAKE_GENERATOR_PLATFORM=x64 ")
-      tryVS <- system(paste0(cmake_cmd, " .."))
-      if (tryVS == 1) {
+      try_vs <- 0
+      local_vs_def <- ""
+      vs_versions <- c("Visual Studio 15 2017 Win64", "Visual Studio 14 2015 Win64", "Visual Studio 12 2013 Win64")
+      for(vs in vs_versions){
+        vs_def <- paste0(" -G \"", vs, "\"")
+        tmp_cmake_cmd <- paste0(cmake_cmd, vs_def)
+        try_vs <- system(paste0(tmp_cmake_cmd, " .."))
         unlink("./*", recursive = TRUE) # Clean up build directory
-        cmake_cmd <- paste0(cmake_base, " -G \"MinGW Makefiles\" ") # Switch to MinGW on failure, try build once
+        if (try_vs == 0) {
+          local_vs_def = vs_def
+          break
+        }
+      }
+      if (try_vs == 1) {
+        cmake_cmd <- paste0(cmake_cmd, " -G \"MinGW Makefiles\" ") # Switch to MinGW on failure, try build once
         system(paste0(cmake_cmd, " ..")) # Must build twice for Windows due sh.exe in Rtools
         build_cmd <- "mingw32-make.exe _lightgbm -j"
       } else {
+        cmake_cmd <- paste0(cmake_cmd, local_vs_def)
         build_cmd <- "cmake --build . --target _lightgbm  --config Release"
         lib_folder <- file.path(R_PACKAGE_SOURCE, "src/Release", fsep = "/")
       }
     }
   }
   
-  if (use_gpu) {
-    cmake_cmd <- paste0(cmake_cmd, " -DUSE_GPU=ON ")
-  }
-  
   # Install
   system(paste0(cmake_cmd, " .."))
   system(build_cmd)