[R-package] move R source files into R-package, reduce duplication in build_r.R (#3087)

* [R-package] move R source files into R-package

* fix linting warning

* stuff

.ci/test.sh

@@ -56,7 +56,7 @@ if [[ $TRAVIS == "true" ]] && [[ $TASK == "lint" ]]; then
     echo "Linting R code"
     Rscript ${BUILD_DIRECTORY}/.ci/lint_r_code.R ${BUILD_DIRECTORY} || exit -1
     echo "Linting C++ code"
-    cpplint --filter=-build/c++11,-build/include_subdir,-build/header_guard,-whitespace/line_length --recursive ./src ./include || exit -1
+    cpplint --filter=-build/c++11,-build/include_subdir,-build/header_guard,-whitespace/line_length --recursive ./src ./include ./R-package || exit -1
     exit 0
 fi
 

.github/CODEOWNERS

@@ -15,9 +15,6 @@ src/    @guolinke @chivee @btrotta
 CMakeLists.txt    @guolinke @chivee @Laurae2 @jameslamb @wxchan @henry0312 @StrikerRUS @huanzhang12 @btrotta
 
 # R code
-include/LightGBM/lightgbm_R.h    @Laurae2 @jameslamb
-include/LightGBM/R_object_helper.h    @Laurae2 @jameslamb
-src/lightgbm_R.cpp    @Laurae2 @jameslamb
 R-package/    @Laurae2 @jameslamb
 *.R    @Laurae2 @jameslamb
 

R-package/.Rbuildignore

-^build_package.R$
+^build_r.R$
 \.gitkeep$
 ^docs$
 ^pkgdown$

src/lightgbm_R.cpp → R-package/src/lightgbm_R.cpp

@@ -2,7 +2,8 @@
  * Copyright (c) 2017 Microsoft Corporation. All rights reserved.
  * Licensed under the MIT License. See LICENSE file in the project root for license information.
  */
-#include <LightGBM/lightgbm_R.h>
+
+#include "lightgbm_R.h"
 
 #include <LightGBM/utils/common.h>
 #include <LightGBM/utils/log.h>

include/LightGBM/lightgbm_R.h → R-package/src/lightgbm_R.h

@@ -6,7 +6,7 @@
 #define LIGHTGBM_R_H_
 
 #include <LightGBM/c_api.h>
-#include <LightGBM/R_object_helper.h>
+#include "R_object_helper.h"
 
 /*!
 * \brief get string message of the last error

build_r.R

@@ -7,6 +7,8 @@
 
 args <- commandArgs(trailingOnly = TRUE)
 INSTALL_AFTER_BUILD <- !("--skip-install" %in% args)
+TEMP_R_DIR <- file.path(getwd(), "lightgbm_r")
+TEMP_SOURCE_DIR <- file.path(TEMP_R_DIR, "src")
 
 # R returns FALSE (not a non-zero exit code) if a file copy operation
 # breaks. Let's fix that
@@ -56,13 +58,13 @@ INSTALL_AFTER_BUILD <- !("--skip-install" %in% args)
 }
 
 # Make a new temporary folder to work in
-unlink(x = "lightgbm_r", recursive = TRUE)
-dir.create("lightgbm_r")
+unlink(x = TEMP_R_DIR, recursive = TRUE)
+dir.create(TEMP_R_DIR)
 
 # copy in the relevant files
 result <- file.copy(
   from = "R-package/./"
-  , to = "lightgbm_r/"
+  , to = sprintf("%s/", TEMP_R_DIR)
   , recursive = TRUE
   , overwrite = TRUE
 )
@@ -70,7 +72,7 @@ result <- file.copy(
 
 result <- file.copy(
   from = "include/"
-  , to = file.path("lightgbm_r", "src/")
+  , to =  sprintf("%s/", TEMP_SOURCE_DIR)
   , recursive = TRUE
   , overwrite = TRUE
 )
@@ -78,7 +80,7 @@ result <- file.copy(
 
 result <- file.copy(
   from = "src/"
-  , to = file.path("lightgbm_r", "src/")
+  , to = sprintf("%s/", TEMP_SOURCE_DIR)
   , recursive = TRUE
   , overwrite = TRUE
 )
@@ -86,7 +88,7 @@ result <- file.copy(
 
 result <- file.copy(
   from = "compute/"
-  , to = file.path("lightgbm_r", "src/")
+  , to = sprintf("%s/", TEMP_SOURCE_DIR)
   , recursive = TRUE
   , overwrite = TRUE
 )
@@ -94,15 +96,29 @@ result <- file.copy(
 
 result <- file.copy(
   from = "CMakeLists.txt"
-  , to = file.path("lightgbm_r", "inst", "bin/")
+  , to = file.path(TEMP_R_DIR, "inst", "bin/")
   , overwrite = TRUE
 )
 .handle_result(result)
 
+# copy files into the place CMake expects
+for (src_file in c("lightgbm_R.cpp", "lightgbm_R.h", "R_object_helper.h")) {
+  result <- file.copy(
+    from = file.path(TEMP_SOURCE_DIR, src_file)
+    , to = file.path(TEMP_SOURCE_DIR, "src", src_file)
+    , overwrite = TRUE
+  )
+  .handle_result(result)
+  result <- file.remove(
+    file.path(TEMP_SOURCE_DIR, src_file)
+  )
+  .handle_result(result)
+}
+
 # NOTE: --keep-empty-dirs is necessary to keep the deep paths expected
 #       by CMake while also meeting the CRAN req to create object files
 #       on demand
-.run_shell_command("R", c("CMD", "build", "lightgbm_r", "--keep-empty-dirs"))
+.run_shell_command("R", c("CMD", "build", TEMP_R_DIR, "--keep-empty-dirs"))
 
 # Install the package
 version <- gsub(
@@ -110,7 +126,7 @@ version <- gsub(
   "",
   grep(
     "Version: "
-    , readLines(con = file.path("lightgbm_r", "DESCRIPTION"))
+    , readLines(con = file.path(TEMP_R_DIR, "DESCRIPTION"))
     , value = TRUE
   )
 )