[m-rev.] for review: delete remaining support for Java native methods

[Julien Fischer]

Hi,

In the absence of objections or any other review comments, I shall commit
this one tonight.

Julien.

On Mon, 20 Jan 2025 at 04:01, Julien Fischer <jfischer at opturion.com> wrote:
>
> For review by anyone.
>
> The request for review is for the concept, the diff is trivial.
>
> -----------------------
>
> Delete remaining support for Java native methods.
>
> Prior to 2009 some of the standard library predicates were implemented using
> Java native methods. These were disabled or replaced by commit 9fc47f5c in
> order to give us pure Java versions of the runtime and standard libraries.
> However, the machinery for supporting native methods was left in place. This
> change deletes that machinery. We are not going to use it again.
>
> library/Mmakefile:
>     Do not build Native.so. (From the looks of it we never installed it
>     anyway.)
>
> java/runtime/Native.c:
>     Delete the C implementations of the native methods ...
>
> java/runtime/Native.java.in:
>     ... and the corresponding Java support for them.
>
> java/runtime/Mmakefile:
>     Delete this Mmakefile, there is no longer anything for it to do.
>
> configure.ac:
>     Do not create Native.java.
>
> Julien.
>
> diff --git a/configure.ac b/configure.ac
> index d761a11..f8469a4 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -5497,7 +5497,6 @@ bindist/bindist.INSTALL
>  bindist/bindist.Makefile
>  runtime/mercury_dotnet.cs
>  java/runtime/Constants.java
> -java/runtime/Native.java
>  compiler/COMP_FLAGS
>  grade_lib/GRADE_LIB_FLAGS
>  library/LIB_FLAGS
> diff --git a/java/runtime/Mmakefile b/java/runtime/Mmakefile
> deleted file mode 100644
> index 1e96cf4..0000000
> --- a/java/runtime/Mmakefile
> +++ /dev/null
> @@ -1,39 +0,0 @@
> -#-----------------------------------------------------------------------------#
> -# vim: ts=8 sw=8 noexpandtab ft=make
> -#-----------------------------------------------------------------------------#
> -
> -# Copyright (C) 2004 The University of Melbourne.
> -# Copyright (C) 2015, 2018 The Mercury team.
> -# This file is distributed under the terms specified in COPYING.LIB.
> -#
> -# This Makefile compiles the shared object for use with
> -# jmercury.runtime.Native.
> -#
> -
> -MERCURY_DIR    = ../..
> -RUNTIME_DIR    = $(MERCURY_DIR)/runtime
> -
> -include $(MERCURY_DIR)/Mmake.common
> -
> -NATIVE_PIC    = Native.$(EXT_FOR_PIC_OBJECTS)
> -NATIVE_SO    = Native.$(EXT_FOR_SHARED_LIB)
> -
> -MAIN_TARGET    = $(NATIVE_SO)
> -
> -PIC_OBJS    = $(RUNTIME_DIR)/mercury_timing.$(EXT_FOR_PIC_OBJECTS) \
> -            $(NATIVE_PIC)
> -
> -CFLAGS        = -I$(RUNTIME_DIR)
> -
> -$(NATIVE_SO):    $(PIC_OBJS)
> -        $(LINK_SHARED_OBJ) -o $(NATIVE_SO) $(PIC_OBJS)
> -
> -$(NATIVE_PIC):    Native.c
> -        $(MGNUC) $(ALL_GRADEFLAGS) $(ALL_MGNUCFLAGS) \
> -            $(CFLAGS_FOR_PIC) -o $(NATIVE_PIC) -c Native.c
> -
> -clean:
> -        rm -f $(PIC_OBJS)
> -
> -realclean:
> -        rm -f $(PIC_OBJS) $(NATIVE_SO) *.class
> diff --git a/java/runtime/Native.c b/java/runtime/Native.c
> deleted file mode 100644
> index 730fb23..0000000
> --- a/java/runtime/Native.c
> +++ /dev/null
> @@ -1,114 +0,0 @@
> -// vim: ts=4 sw=4 expandtab ft=c
> -//
> -// Copyright (C) 2004, 2006 The University of Melbourne.
> -// Copyright (C) 2018 The Mercury team.
> -// This file is distributed under the terms specified in COPYING.LIB.
> -//
> -
> -// File: Native.c - Native code for java/runtime/Native.java.
> -
> -#include <jni.h>
> -
> -/*
> - * Class:     Native
> - * Method:    clock
> - * Signature: ()I
> - */
> -JNIEXPORT jint JNICALL Java_jmercury_runtime_Native_clock(JNIEnv *, jclass);
> -
> -/*
> - * Class:     Native
> - * Method:    clocks_per_sec
> - * Signature: ()I
> - */
> -JNIEXPORT jint JNICALL Java_jmercury_runtime_Native_clocks_1per_1sec(
> -        JNIEnv *, jclass);
> -
> -/*
> - * Class:     Native
> - * Method:    times
> - * Signature: ()[I
> - */
> -JNIEXPORT jintArray JNICALL Java_jmercury_runtime_Native_times(
> -        JNIEnv *, jclass);
> -
> -/*
> - * Class:     Native
> - * Method:    clk_tck
> - * Signature: ()I
> - */
> -JNIEXPORT jint JNICALL Java_jmercury_runtime_Native_clk_1tck(JNIEnv *, jclass);
> -
> -/*
> - * Class:     Native
> - * Method:    get_user_cpu_milliseconds
> - * Signature: ()I
> - */
> -JNIEXPORT jint JNICALL
> Java_jmercury_runtime_Native_get_1user_1cpu_1milliseconds(
> -        JNIEnv *, jclass);
> -
> -#include "mercury_imp.h"
> -#include "mercury_timing.h"
> -
> -#include <time.h>
> -#ifdef MR_HAVE_SYS_TYPES_H
> -    #include <sys/types.h>
> -#endif
> -#ifdef MR_HAVE_SYS_TIMES_H
> -    #include <sys/times.h>
> -#endif
> -#ifdef MR_HAVE_UNISTD_H
> -    #include <unistd.h>
> -#endif
> -
> -JNIEXPORT jint JNICALL
> -Java_jmercury_runtime_Native_clock(JNIEnv *env, jclass obj) {
> -    return (MR_Integer) clock();
> -}
> -
> -JNIEXPORT jint JNICALL
> -Java_jmercury_runtime_Native_clocks_1per_1sec(JNIEnv *env, jclass obj) {
> -    return CLOCKS_PER_SEC;
> -}
> -
> -JNIEXPORT jintArray JNICALL
> -Java_jmercury_runtime_Native_times(JNIEnv *env, jclass obj) {
> -    jint        intarray[5];
> -    jintArray   result;
> -
> -#ifdef MR_HAVE_POSIX_TIMES
> -    struct tms  t;
> -
> -    intarray[0] = (MR_Integer) times(&t);
> -    intarray[1] = (MR_Integer) t.tms_utime;
> -    intarray[2] = (MR_Integer) t.tms_stime;
> -    intarray[3] = (MR_Integer) t.tms_cutime;
> -    intarray[4] = (MR_Integer) t.tms_cstime;
> -#else
> -    intarray[0] = -1;
> -#endif
> -
> -    result = (*env)->NewIntArray(env, 5);
> -    if (result != NULL) {
> -        (*env)->SetIntArrayRegion(env, result, 0, 5, intarray);
> -    }
> -
> -    return result;
> -}
> -
> -JNIEXPORT jint JNICALL Java_jmercury_runtime_Native_clk_1tck(
> -        JNIEnv *env, jclass obj)
> -{
> -#if defined(MR_CLOCK_TICKS_PER_SECOND)
> -    return MR_CLOCK_TICKS_PER_SECOND;
> -#else
> -    return -1;
> -#endif
> -}
> -
> -JNIEXPORT jint JNICALL
> -Java_jmercury_runtime_Native_get_1user_1cpu_1milliseconds(
> -        JNIEnv *env, jclass obj)
> -{
> -    return MR_get_user_cpu_milliseconds();
> -}
> diff --git a/java/runtime/Native.java.in b/java/runtime/Native.java.in
> deleted file mode 100644
> index 0f33077..0000000
> --- a/java/runtime/Native.java.in
> +++ /dev/null
> @@ -1,140 +0,0 @@
> -// vim: ts=4 sw=4 expandtab ft=java
> -//
> -// @configure_input@
> -//
> -// Copyright (C) 2004, 2006 The University of Melbourne.
> -// Copyright (C) 2018 The Mercury team.
> -// This file is distributed under the terms specified in COPYING.LIB.
> -//
> -//
> -// This class exists to provide any native functionality required by the Java
> -// implementation.  It uses JNI to access a shared object which it searches
> -// for in all the directories listed in the current CLASSPATH.
> -//
> -// At the moment the only services provided are those relating to timing.
> -//
> -
> -package jmercury.runtime;
> -
> -public class Native {
> -    /**
> -     * SHARED_OBJ is the name of the shared object which contains
> -     * all the compiled native code.
> -     */
> -    private static final java.lang.String   SHARED_OBJ =
> -        "Native. at EXT_FOR_SHARED_LIB@";
> -
> -    /**
> -     * attemptedLoad records whether or not the user has yet attempted
> -     * to load the shared library.
> -     */
> -    private static boolean  attemptedLoad = false;
> -
> -    /**
> -     * available and isAvailable() are true when native functionality
> -     * is available. (ie SHARED_OBJ was loaded successfully)
> -     */
> -    private static boolean  available  = false;
> -
> -    /**
> -     * isAvailable() as the side effect of attempting to load the library
> -     * if this has not already been done.
> -     */
> -    public static boolean isAvailable() {
> -        if (!attemptedLoad) {
> -            load_library();
> -        }
> -        return available;
> -    }
> -
> -    static {
> -        load_library();
> -    }
> -
> -    /**
> -     * load_library():
> -     *  Searches all the directories listed in the classpath,
> -     *  (including the directories containing each jar file) for the
> -     *  shared object SHARED_OBJ, and attempts to load this file if found.
> -     *  Also searches in the subdirectory Constants.MR_FULLARCH.
> -     *  Sets available to true if successful, false otherwise.
> -     */
> -    private static void load_library() {
> -        attemptedLoad = true;
> -
> -        java.util.StringTokenizer classpath =
> -            new java.util.StringTokenizer(
> -                java.lang.System.getProperty("java.class.path"),
> -                java.lang.System.getProperty("path.separator")
> -            );
> -
> -        while (classpath.hasMoreTokens()) {
> -            java.io.File dir;
> -            java.io.File entry = new java.io.File(classpath.nextToken());
> -
> -            try {
> -                if (entry.isDirectory()) {
> -                    dir = entry;
> -                } else {
> -                    dir = entry.getParentFile();
> -                }
> -                if (dir == null) {
> -                    dir = new java.io.File("");
> -                }
> -
> -                java.io.File match = new java.io.File(dir, SHARED_OBJ);
> -                if (match.exists() == false) {
> -                    dir = new java.io.File(dir, Constants.MR_FULLARCH);
> -                    match = new java.io.File(dir, SHARED_OBJ);
> -                }
> -
> -                java.lang.System.load(match.getAbsolutePath());
> -                available = true;
> -                return;
> -            }
> -            catch (java.lang.Exception e) {
> -                continue;
> -            }
> -        } // while classpath.hasMoreTokens()
> -
> -        return;
> -    } // load_library()
> -
> -    /**
> -     * clock():
> -     *  Calls clock() from the <time.h> library.
> -     */
> -    public static native int clock();
> -
> -    /**
> -     * clocks_per_sec():
> -     *  Returns the number of "clocks" per sec as defined by CLOCKS_PER_SEC.
> -     */
> -    public static native int clocks_per_sec();
> -
> -    /**
> -     * times():
> -     *  Calls times() from the <time.h> library.  Results are returned
> -     *  in an int array of the form:
> -     *  { <return value>, utime, stime, cutime, cstime }
> -     *  If POSIX times are not available, <return value> will be set to -1,
> -     *  and the other values are undefined.
> -     *  Returns null if the array cannot be constructed.
> -     */
> -    public static native int[] times();
> -
> -    /**
> -     * clk_tck():
> -     *  Returns the number of "clock ticks" per second as defined by
> -     *  sysconf(_SC_CLK_TCK). A `clock_t' value returned by 'times()'
> -     *  can be divided by this value to obtain a time in seconds.
> -     */
> -    public static native int clk_tck();
> -
> -    /**
> -     * get_user_cpu_milliseconds():
> -     *  Native method to return the CPU time consumed by the process,
> -     *  in milliseconds, from an arbitrary initial time.
> -     */
> -    public static native int get_user_cpu_milliseconds();
> -}
> diff --git a/library/Mmakefile b/library/Mmakefile
> index 99f88bc..61933b6 100644
> --- a/library/Mmakefile
> +++ b/library/Mmakefile
> @@ -428,12 +428,6 @@ $(RT_LIB_NAME).jar: copy_java_runtime_files
>      $(JAVAC) $(ALL_JAVACFLAGS) jmercury/runtime/*.java
>      $(JAR) $(JAR_CREATE_FLAGS) $(RT_LIB_NAME).jar jmercury/runtime/*.class
>      $(JAR) i $(RT_LIB_NAME).jar
> -    # -+cd jmercury/runtime && mmake $(NATIVE_SO)
> -    # -cp jmercury/runtime/$(NATIVE_SO) .
> -
> -# This shared object was used to implement some standard library methods,
> -# but currently not.
> -NATIVE_SO = Native.$(EXT_FOR_SHARED_LIB)
>
>  #-----------------------------------------------------------------------------#
>
> @@ -566,7 +560,7 @@ realclean_local:
>      rm -rf jmercury
>      rm -f mr_int.class mr_float.class mr_char.class
>      rm -f mr_int\$$*.class mr_float\$$*.class mr_char\$$*.class
> -    rm -f $(STD_LIB_NAME).jar $(RT_LIB_NAME).jar $(NATIVE_SO)
> +    rm -f $(STD_LIB_NAME).jar $(RT_LIB_NAME).jar
>
>  #-----------------------------------------------------------------------------#