Update CHANGELOG and improve some more error messages

Author: steve-s

CHANGELOG.md

@@ -2,16 +2,25 @@
 
 New features:
 
+* new Graal LLVM based back-end for running packages native code.
+  * The default {FASTR_HOME}/etc/Makeconf is configured to use the Graal LLVM toolchain to build the native code of R packages.
+    * The toolchain builds standard native binaries for a given plarform and also embeds the corresponding LLVM bitcode in them.
+    * R builtin `fastr.setToolchain(name)` (`name` can be `llvm` or `native`) sets the compiler toolchain used for package building (modifies etc/Makeconf).
+    * To switch back to the previous toolchain configuration that used `GCC`, execute `fastr.setToolchain("native")`.
+  * Option `--R.BackEnd` specifies the default backend used to execute packages native code.
+    * Different R packages can be run via different backends in one FastR context.
+    * `--R.BackEnd=native`, the default, is JNI based backend that runs directly the actual native code.
+    * `--R.BackEnd=llvm` is the new LLVM backend that loads the LLVM bitcode embedded in package libraries and runs it via Graal LLVM.
+    * `--R.BackEndNative=pkg1,pkg2,...` enumerates packages whose native code will be executed by the native backend.
+    * `--R.BackEndLLVM=pkg1,pkg2,...` enumerates packages whose native code will be executed by the LLVM backend.
+    * Note: All `--R.BackEnd*` options are passed to R subprocesses.
+  * Debugging of packages native code with LLVM backend.
+    * Option `--R.DebugLLVMLibs` activates debugging of native code using the bundled LLVM bitcode.
+    * Builtin `fastr.useDebugMakevars(use)` activates/deactivates a special `etc/Makevars.site` tailored for building the packages native code for debugging.
 * `gc` attempts to invoke Java GC when FastR is run with `--R.EnableExplicitGC=true`
   * this is intended only for testing purposes and it is not recommended to run GC explicitly in FastR.
   * `gc` is not invoking Java GC by default because GNU-R GC and Java GC are fundamentally
     different and this may lead to unintended behavior.
-* Option `--R.BackEnd` specifies an RFFI backend. `--R.BackEnd=native`, the default, activates the JNI based backend, while `--R.BackEnd=llvm` activates the LLVM backend loading the LLVM bitcode bundled with package libraries. Note: All ``--R.BackEnd*` options are passed to R subprocesses.
-* Option `--R.BackEndNative` enumerates packages whose native code will be executed by the native backend (JNI based)
-* Option `--R.BackEndLLVM` enumerates packages whose native code will be executed by the LLVM backend
-* Option `--R.DebugLLVMLibs` activates debugging of native code using the bundled LLVM bitcode
-* Builtin `fastr.useDebugMakevars(use)` activates/deactivates a special `etc/Makevars.site` for debugging native code
-* Builtin `fastr.setToolchain(name)` (`name` can be `llvm` or `native`) sets the compiler toolchain used for package building
 
 Added missing R builtins and C APIs
 
@@ -34,7 +43,6 @@ Bug fixes:
 * failures when working with large vectors (>1GB)
 
 
-
 # 19.2.0
 
 New features:

com.oracle.truffle.r.native/run/configure_fastr

@@ -102,9 +102,9 @@ done
     res=$?
     if [[ $res != 0 ]]; then
       echo "Cannot build a simple C program linking with libgfortran, libgcc_s, and libquadmath."
-      echo "Please install GCC using:"
-      echo "    On Debian based systems: apt-get install build-essential"
-      echo "    On CentOS/RHEL: yum groupinstall \"Developent Tools\""
+      echo "Please install GCC and gfortran using:"
+      echo "    On Debian based systems: sudo apt-get install build-essential gfortran"
+      echo "    On CentOS/RHEL/Oracle Linux: sudo yum groupinstall \"Developent Tools\"; yum install gcc-gfortran"
 	  echo ""	
       printHelp
       exit 1

com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/ffi/DLL.java

@@ -46,6 +46,7 @@
 import com.oracle.truffle.api.profiles.ConditionProfile;
 import com.oracle.truffle.api.source.SourceSection;
 import com.oracle.truffle.r.runtime.FileSystemUtils;
+import com.oracle.truffle.r.runtime.REnvVars;
 import com.oracle.truffle.r.runtime.RError;
 import com.oracle.truffle.r.runtime.RError.Message;
 import com.oracle.truffle.r.runtime.RError.RErrorException;
@@ -591,11 +592,15 @@ public static DLLInfo loadLibR(RContext context, String path, Function<String, L
         try {
             handle = load.apply(path);
         } catch (UnsatisfiedLinkError ex) {
-            throw RSuicide.rSuicide(context, "error loading libR from: " + path + ".\n" +
-                            "If running on the NFI backend, did you provide the location of libtrufflenfi.so as the value of the system " +
-                            "property 'truffle.nfi.library'?\nThe current value is '" + System.getProperty("truffle.nfi.library") + "'.\n" +
-                            "Is the OpenMP runtime library (libgomp.so) present on your system? This library is, e.g., typically part of the GCC package.\n" +
-                            "Details: " + ex.getMessage());
+            throw RSuicide.rSuicide(context, String.format("error loading libR from: %s.\n" +
+                            "Message: " + ex.getMessage() + "\n\n" +
+                            "Troubleshooting: \n\n" +
+                            " * If you have not already %s/bin/configure_fastr yet, try running it.\n\n" +
+                            " * Is the OpenMP runtime library (libgomp.so) present on your system? This library is, e.g., typically part of the 'gcc' package.\n\n" +
+                            " * Are the gfortran runtime libraries present on your system? These libraries are, e.g., typically part of the 'gfortran' package.\n\n" +
+                            " * Did you provide the location of libtrufflenfi.so as the value of the system " +
+                            "property 'truffle.nfi.library'? The current value is '%s'.\n\n",
+                            path, REnvVars.rHome(), System.getProperty("truffle.nfi.library")));
         } catch (Throwable ex) {
             throw RSuicide.rSuicide(context, "error loading libR from: " + path + ". Details: " + ex.getMessage());
         }

mx.fastr/mx_fastr_dists.py

@@ -301,16 +301,16 @@ def mx_register_dynamic_suite_constituents(register_project, register_distributi
         ],
         include_in_polyglot=False,
         post_install_msg="NOTES:\n---------------\n" +
-             "The user specific library directory was not created automatically. " +
-             "You can either create the directory manually or edit file ${graalvm_languages_dir}/R/etc/Renviron to change it to any desired location. " +
-             "Without user specific library directory, users will need write permission for the GraalVM home directory in order to install R packages. " +
-             "\n\n" +
              "FastR needs a system-dependent configuration because it links with some system libraries. " +
              "A generic configuration that works out of the box on most Linux distributions with GCC and gfortran installed is provided by default. " +
              "If you are on another system (e.g., MacOS), wish to fine-tune the configuration to your system, or should you encounter any " +
              "issues when running FastR or during R packages installation, try running the following script that adjusts " +
              "the configuration to your system: \n" +
              "    ${graalvm_languages_dir}/R/bin/configure_fastr\n\n" +
+             "The user specific library directory was not created automatically. " +
+             "You can either create the directory manually or edit file ${graalvm_languages_dir}/R/etc/Renviron to change it to any desired location. " +
+             "Without the user specific library directory, users will need write permission for the GraalVM home directory in order to install R packages. " +
+             "\n\n" +
              "The R component comes without native image by default. If you wish to build the native image, " +
              "which provides faster startup, but slightly slower peak performance, then run the following:\n" +
              "    ${graalvm_languages_dir}/R/bin/install_r_native_image\n\n" +