/*
 * Copyright (c) 2013, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.oracle.objectfile;

import java.util.HashMap;
import java.util.Map;

import com.oracle.objectfile.ObjectFile.Format;

Some common section names, and code to convert to/from their platform-dependent (or rather,
format-specific) string representations.
/**
 * Some common section names, and code to convert to/from their platform-dependent (or rather,
 * format-specific) string representations.
 */
public abstract class SectionName {

    private static class ProgbitsSectionName extends SectionName {

        ProgbitsSectionName(String name) {
            super(name);
        }

    }

    private static class NobitsSectionName extends SectionName {

        NobitsSectionName(String name) {
            super(name);
        }

    }

    /*
     * This was an enum, but in reality it needs to be extensible, so we fake an enum in class form.
     */
    // "standard" section names
    public static final SectionName DATA = new ProgbitsSectionName("data");
    public static final SectionName RODATA = new ProgbitsSectionName("rodata") {

        // On Mach-O, the read-only data goes in the __DATA,__const section.

        @Override
        public String getSegmentName(Format f) {
            final String result;
            if (f == Format.MACH_O) {
                result = "__DATA";
            } else {
                result = super.getSegmentName(f);
            }
            return result;
        }

        @Override
        public String getFormatDependentName(Format f) {
            final String result;
            if (f == Format.MACH_O) {
                result = "__const";
            } else {
                result = super.getFormatDependentName(f);
            }
            return result;
        }

    };
    public static final SectionName TEXT = new ProgbitsSectionName("text");
    public static final SectionName BSS = new NobitsSectionName("bss");
    public static final SectionName SVM_HEAP = new ProgbitsSectionName("svm_heap");
    // proprietary
    public static final SectionName APPLE_NAMES = new ProgbitsSectionName("apple_names");
    public static final SectionName APPLE_TYPES = new ProgbitsSectionName("apple_types");
    // not a typo!
    public static final SectionName APPLE_NAMESPACE = new ProgbitsSectionName("apple_namespac");
    public static final SectionName APPLE_OBJC = new ProgbitsSectionName("apple_objc");
    public static final SectionName LLVM_STACKMAPS = new ProgbitsSectionName("llvm_stackmaps");

    private static final SectionName[] myValues;

    static {
        myValues = new SectionName[]{DATA, RODATA, TEXT, BSS, APPLE_NAMES, APPLE_TYPES, APPLE_NAMESPACE, APPLE_OBJC, LLVM_STACKMAPS};
    }

    private static String getFormatPrefix(ObjectFile.Format f) {
        switch (f) {
            case ELF:
            case PECOFF:
                return ".";
            case MACH_O:
                return "__";
            default:
                throw new IllegalStateException("unsupported format: " + f);
        }
    }

    
Return a "suggested" segment name for sections of this name, given an object file format.
Some object file formats (Mach-O) require that all sections exist within a segment. Others
(ELF) impose no such requirement. For the latter formats, this will return null (noting that
ELF does not even have segment names). For the former, it will return some segment name. By
default, Mach-O segment names are the section name uppercased. Note that the value returned
by this function is designed to be passed to the (String, String, ...) overload of
new{UserDefined,Progbits,Nobits}Section in ObjectFile.
Params:
f – 
Returns:
a segment name, or null if none is necessary/**
     * Return a "suggested" segment name for sections of this name, given an object file format.
     * Some object file formats (Mach-O) require that all sections exist within a segment. Others
     * (ELF) impose no such requirement. For the latter formats, this will return null (noting that
     * ELF does not even have segment names). For the former, it will return some segment name. By
     * default, Mach-O segment names are the section name uppercased. Note that the value returned
     * by this function is designed to be passed to the (String, String, ...) overload of
     * new{UserDefined,Progbits,Nobits}Section in ObjectFile.
     *
     * @param f
     * @return a segment name, or null if none is necessary
     */
    public String getSegmentName(ObjectFile.Format f) {
        // default implementation
        switch (f) {
            case MACH_O:
                return getFormatDependentName(f).toUpperCase();
            default:
            case ELF:
                return null;
        }
    }

    protected static final Map<String, SectionName> NAMES_MAP = new HashMap<>();

    static {
        for (SectionName name : myValues) {
            /*
             * We indiscriminately stuff into the map: 1. the format-independent name; 2. the
             * format-dependent names, for all formats.
             */
            for (Format f : ObjectFile.Format.values()) {
                NAMES_MAP.put(name.getFormatDependentName(f), name);
            }
        }
    }

    // this is the string argument to our constructed values, above,
    // e.g. TEXT("text") <-- it's "text"
    protected final String platformIndependentName;

    public String getPlatformIndependentName() {
        return this.platformIndependentName;
    }

    protected SectionName(String n) {
        platformIndependentName = n;
    }

    public String getFormatDependentName(Format f) {
        return getFormatPrefix(f) + platformIndependentName;
    }

    public static SectionName from(String n) {
        final SectionName result = NAMES_MAP.get(n);
        return result;
    }

}