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package jdk.internal.foreign;

import jdk.internal.foreign.abi.fallback.FallbackLinker;
import jdk.internal.vm.ForeignLinkerSupport;
import jdk.internal.util.OperatingSystem;
import jdk.internal.util.StaticProperty;

import static java.lang.foreign.ValueLayout.ADDRESS;

public enum CABI {
    SYS_V,
    WIN_64,
    LINUX_AARCH_64,
    MAC_OS_AARCH_64,
    WIN_AARCH_64,
    AIX_PPC_64,
    LINUX_PPC_64,
    LINUX_PPC_64_LE,
    LINUX_RISCV_64,
    LINUX_S390,
    FALLBACK,
    UNSUPPORTED;

    private static final CABI CURRENT = computeCurrent();

    private static CABI computeCurrent() {
        String abi = System.getProperty("jdk.internal.foreign.CABI");
        if (abi != null) {
            return CABI.valueOf(abi);
        }

        if (ForeignLinkerSupport.isSupported()) {
            // figure out the ABI based on the platform
            String arch = StaticProperty.osArch();
            long addressSize = ADDRESS.byteSize();
            // might be running in a 32-bit VM on a 64-bit platform.
            // addressSize will be correctly 32
            if ((arch.equals("amd64") || arch.equals("x86_64")) && addressSize == 8) {
                if (OperatingSystem.isWindows()) {
                    return WIN_64;
                } else {
                    return SYS_V;
                }
            } else if (arch.equals("aarch64")) {
                if (OperatingSystem.isMacOS()) {
                    return MAC_OS_AARCH_64;
                } else if (OperatingSystem.isWindows()) {
                    return WIN_AARCH_64;
                } else {
                    // The Linux ABI follows the standard AAPCS ABI
                    return LINUX_AARCH_64;
                }
            } else if (arch.equals("ppc64")) {
                if (OperatingSystem.isLinux()) {
                    return LINUX_PPC_64;
                } else if (OperatingSystem.isAix()) {
                    return AIX_PPC_64;
                }
            } else if (arch.equals("ppc64le")) {
                if (OperatingSystem.isLinux()) {
                    return LINUX_PPC_64_LE;
                }
            } else if (arch.equals("riscv64")) {
                if (OperatingSystem.isLinux()) {
                    return LINUX_RISCV_64;
                }
            } else if (arch.equals("s390x")) {
                if (OperatingSystem.isLinux()) {
                    return LINUX_S390;
                }
        }
        } else if (FallbackLinker.isSupported()) {
            return FALLBACK; // fallback linker
        }

        return UNSUPPORTED;
    }

    public static CABI current() {
        return CURRENT;
    }
}
