[SPARK-26014][R] Deprecate R prior to version 3.4 in SparkR

## What changes were proposed in this pull request?

This PR proposes to bump up the minimum versions of R from 3.1 to 3.4.

R version. 3.1.x is too old. It's released 4.5 years ago. R 3.4.0 is released 1.5 years ago. Considering the timing for Spark 3.0, deprecating lower versions, bumping up R to 3.4 might be reasonable option.

It should be good to deprecate and drop < R 3.4 support.

## How was this patch tested?

Jenkins tests.

Closes #23012 from HyukjinKwon/SPARK-26014.

Authored-by: hyukjinkwon <gurwls223@apache.org>
Signed-off-by: hyukjinkwon <gurwls223@apache.org>

R/WINDOWS.md

@@ -3,7 +3,7 @@
 To build SparkR on Windows, the following steps are required
 
 1. Install R (>= 3.1) and [Rtools](http://cran.r-project.org/bin/windows/Rtools/). Make sure to
-include Rtools and R in `PATH`.
+include Rtools and R in `PATH`. Note that support for R prior to version 3.4 is deprecated as of Spark 3.0.0.
 
 2. Install
 [JDK8](http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html) and set

R/pkg/DESCRIPTION

@@ -15,7 +15,7 @@ URL: http://www.apache.org/ http://spark.apache.org/
 BugReports: http://spark.apache.org/contributing.html
 SystemRequirements: Java (== 8)
 Depends:
-    R (>= 3.0),
+    R (>= 3.1),
     methods
 Suggests:
     knitr,

R/pkg/inst/profile/general.R

@@ -16,6 +16,10 @@
 #
 
 .First <- function() {
+  if (utils::compareVersion(paste0(R.version$major, ".", R.version$minor), "3.4.0") == -1) {
+    warning("Support for R prior to version 3.4 is deprecated since Spark 3.0.0")
+  }
+
   packageDir <- Sys.getenv("SPARKR_PACKAGE_DIR")
   dirs <- strsplit(packageDir, ",")[[1]]
   .libPaths(c(dirs, .libPaths()))

R/pkg/inst/profile/shell.R

@@ -16,6 +16,10 @@
 #
 
 .First <- function() {
+  if (utils::compareVersion(paste0(R.version$major, ".", R.version$minor), "3.4.0") == -1) {
+    warning("Support for R prior to version 3.4 is deprecated since Spark 3.0.0")
+  }
+
   home <- Sys.getenv("SPARK_HOME")
   .libPaths(c(file.path(home, "R", "lib"), .libPaths()))
   Sys.setenv(NOAWT = 1)

docs/index.md

@@ -31,7 +31,8 @@ Spark runs on both Windows and UNIX-like systems (e.g. Linux, Mac OS). It's easy
 locally on one machine --- all you need is to have `java` installed on your system `PATH`,
 or the `JAVA_HOME` environment variable pointing to a Java installation.
 
-Spark runs on Java 8+, Python 2.7+/3.4+ and R 3.1+. For the Scala API, Spark {{site.SPARK_VERSION}}
+Spark runs on Java 8+, Python 2.7+/3.4+ and R 3.1+. R prior to version 3.4 support is deprecated as of Spark 3.0.0.
+For the Scala API, Spark {{site.SPARK_VERSION}}
 uses Scala {{site.SCALA_BINARY_VERSION}}. You will need to use a compatible Scala version
 ({{site.SCALA_BINARY_VERSION}}.x).