/**
 * Compiler implementation of the $(LINK2 http://www.dlang.org, D programming language)
 *
 * Copyright: Copyright (c) 1999-2017 by Digital Mars, All Rights Reserved
 * Authors: Walter Bright, http://www.digitalmars.com
 * License:   $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
 * Source:    $(LINK2 https://github.com/dlang/dmd/blob/master/src/ddmd/cppmangle.d, _cppmangle.d)
 */

module ddmd.cppmangle;

// Online documentation: https://dlang.org/phobos/ddmd_cppmangle.html

import core.stdc.string;
import core.stdc.stdio;

import ddmd.arraytypes;
import ddmd.declaration;
import ddmd.dsymbol;
import ddmd.dtemplate;
import ddmd.errors;
import ddmd.expression;
import ddmd.func;
import ddmd.globals;
import ddmd.id;
import ddmd.mtype;
import ddmd.root.outbuffer;
import ddmd.root.rootobject;
import ddmd.target;
import ddmd.tokens;
import ddmd.typesem;
import ddmd.visitor;

/* Do mangling for C++ linkage.
 * No attempt is made to support mangling of templates, operator
 * overloading, or special functions.
 *
 * So why don't we use the C++ ABI for D name mangling?
 * Because D supports a lot of things (like modules) that the C++
 * ABI has no concept of. These affect every D mangled name,
 * so nothing would be compatible anyway.
 */

/*
 * Follows Itanium C++ ABI 1.86
 */
extern (C++) final class CppMangleVisitor : Visitor
{
    alias visit = super.visit;
    Objects components;
    OutBuffer buf;
    bool is_top_level;
    bool components_on;

    void writeBase36(size_t i)
    {
        if (i >= 36)
        {
            writeBase36(i / 36);
            i %= 36;
        }
        if (i < 10)
            buf.writeByte(cast(char)(i + '0'));
        else if (i < 36)
            buf.writeByte(cast(char)(i - 10 + 'A'));
        else
            assert(0);
    }

    bool substitute(RootObject p)
    {
        //printf("substitute %s\n", p ? p.toChars() : null);
        if (components_on)
            for (size_t i = 0; i < components.dim; i++)
            {
                //printf("    component[%d] = %s\n", i, components[i] ? components[i].toChars() : null);
                if (p == components[i])
                {
                    //printf("\tmatch\n");
                    /* Sequence is S_, S0_, .., S9_, SA_, ..., SZ_, S10_, ...
                     */
                    buf.writeByte('S');
                    if (i)
                        writeBase36(i - 1);
                    buf.writeByte('_');
                    return true;
                }
            }
        return false;
    }

    bool exist(RootObject p)
    {
        //printf("exist %s\n", p ? p.toChars() : null);
        if (components_on)
            for (size_t i = 0; i < components.dim; i++)
            {
                if (p == components[i])
                {
                    return true;
                }
            }
        return false;
    }

    void store(RootObject p)
    {
        //printf("store %s\n", p ? p.toChars() : "null");
        if (components_on)
            components.push(p);
    }

    void source_name(Dsymbol s, bool skipname = false)
    {
        //printf("source_name(%s)\n", s.toChars());
        TemplateInstance ti = s.isTemplateInstance();
        if (ti)
        {
            if (!skipname && !substitute(ti.tempdecl))
            {
                store(ti.tempdecl);
                const(char)* name = ti.tempdecl.toAlias().ident.toChars();
                buf.printf("%d%s", strlen(name), name);
            }
            buf.writeByte('I');
            bool is_var_arg = false;
            for (size_t i = 0; i < ti.tiargs.dim; i++)
            {
                RootObject o = cast(RootObject)(*ti.tiargs)[i];
                TemplateParameter tp = null;
                TemplateValueParameter tv = null;
                TemplateTupleParameter tt = null;
                if (!is_var_arg)
                {
                    TemplateDeclaration td = ti.tempdecl.isTemplateDeclaration();
                    assert(td);
                    tp = (*td.parameters)[i];
                    tv = tp.isTemplateValueParameter();
                    tt = tp.isTemplateTupleParameter();
                }
                /*
                 *           <template-arg> ::= <type>            # type or template
                 *                          ::= <expr-primary>   # simple expressions
                 */
                if (tt)
                {
                    buf.writeByte('I');
                    is_var_arg = true;
                    tp = null;
                }
                if (tv)
                {
                    // <expr-primary> ::= L <type> <value number> E                   # integer literal
                    if (tv.valType.isintegral())
                    {
                        Expression e = isExpression(o);
                        assert(e);
                        buf.writeByte('L');
                        tv.valType.accept(this);
                        if (tv.valType.isunsigned())
                        {
                            buf.printf("%llu", e.toUInteger());
                        }
                        else
                        {
                            sinteger_t val = e.toInteger();
                            if (val < 0)
                            {
                                val = -val;
                                buf.writeByte('n');
                            }
                            buf.printf("%lld", val);
                        }
                        buf.writeByte('E');
                    }
                    else
                    {
                        s.error("Internal Compiler Error: C++ %s template value parameter is not supported", tv.valType.toChars());
                        fatal();
                    }
                }
                else if (!tp || tp.isTemplateTypeParameter())
                {
                    Type t = isType(o);
                    assert(t);
                    t.accept(this);
                }
                else if (tp.isTemplateAliasParameter())
                {
                    Dsymbol d = isDsymbol(o);
                    Expression e = isExpression(o);
                    if (!d && !e)
                    {
                        s.error("Internal Compiler Error: %s is unsupported parameter for C++ template: (%s)", o.toChars());
                        fatal();
                    }
                    if (d && d.isFuncDeclaration())
                    {
                        bool is_nested = d.toParent() && !d.toParent().isModule() && (cast(TypeFunction)d.isFuncDeclaration().type).linkage == LINKcpp;
                        if (is_nested)
                            buf.writeByte('X');
                        buf.writeByte('L');
                        mangle_function(d.isFuncDeclaration());
                        buf.writeByte('E');
                        if (is_nested)
                            buf.writeByte('E');
                    }
                    else if (e && e.op == TOKvar && (cast(VarExp)e).var.isVarDeclaration())
                    {
                        VarDeclaration vd = (cast(VarExp)e).var.isVarDeclaration();
                        buf.writeByte('L');
                        mangle_variable(vd, true);
                        buf.writeByte('E');
                    }
                    else if (d && d.isTemplateDeclaration() && d.isTemplateDeclaration().onemember)
                    {
                        if (!substitute(d))
                        {
                            cpp_mangle_name(d, false);
                        }
                    }
                    else
                    {
                        s.error("Internal Compiler Error: %s is unsupported parameter for C++ template", o.toChars());
                        fatal();
                    }
                }
                else
                {
                    s.error("Internal Compiler Error: C++ templates support only integral value, type parameters, alias templates and alias function parameters");
                    fatal();
                }
            }
            if (is_var_arg)
            {
                buf.writeByte('E');
            }
            buf.writeByte('E');
            return;
        }
        else
        {
            const(char)* name = s.ident.toChars();
            buf.printf("%d%s", strlen(name), name);
        }
    }

    void prefix_name(Dsymbol s)
    {
        //printf("prefix_name(%s)\n", s.toChars());
        if (!substitute(s))
        {
            Dsymbol p = s.toParent();
            if (p && p.isTemplateInstance())
            {
                s = p;
                if (exist(p.isTemplateInstance().tempdecl))
                {
                    p = null;
                }
                else
                {
                    p = p.toParent();
                }
            }
            if (p && !p.isModule())
            {
                if (p.ident == Id.std && is_initial_qualifier(p))
                    buf.writestring("St");
                else
                    prefix_name(p);
            }
            if (!(s.ident == Id.std && is_initial_qualifier(s)))
                store(s);
            source_name(s);
        }
    }

    /* Is s the initial qualifier?
     */
    bool is_initial_qualifier(Dsymbol s)
    {
        Dsymbol p = s.toParent();
        if (p && p.isTemplateInstance())
        {
            if (exist(p.isTemplateInstance().tempdecl))
            {
                return true;
            }
            p = p.toParent();
        }
        return !p || p.isModule();
    }

    void cpp_mangle_name(Dsymbol s, bool qualified)
    {
        //printf("cpp_mangle_name(%s, %d)\n", s.toChars(), qualified);
        Dsymbol p = s.toParent();
        Dsymbol se = s;
        bool dont_write_prefix = false;
        if (p && p.isTemplateInstance())
        {
            se = p;
            if (exist(p.isTemplateInstance().tempdecl))
                dont_write_prefix = true;
            p = p.toParent();
        }
        if (p && !p.isModule())
        {
            /* The N..E is not required if:
             * 1. the parent is 'std'
             * 2. 'std' is the initial qualifier
             * 3. there is no CV-qualifier or a ref-qualifier for a member function
             * ABI 5.1.8
             */
            if (p.ident == Id.std && is_initial_qualifier(p) && !qualified)
            {
                if (s.ident == Id.allocator)
                {
                    buf.writestring("Sa"); // "Sa" is short for ::std::allocator
                    source_name(se, true);
                }
                else if (s.ident == Id.basic_string)
                {
                    components_on = false; // turn off substitutions
                    buf.writestring("Sb"); // "Sb" is short for ::std::basic_string
                    size_t off = buf.offset;
                    source_name(se, true);
                    components_on = true;
                    // Replace ::std::basic_string < char, ::std::char_traits<char>, ::std::allocator<char> >
                    // with Ss
                    //printf("xx: '%.*s'\n", (int)(buf.offset - off), buf.data + off);
                    if (buf.offset - off >= 26 && memcmp(buf.data + off, "IcSt11char_traitsIcESaIcEE".ptr, 26) == 0)
                    {
                        buf.remove(off - 2, 28);
                        buf.insert(off - 2, "Ss");
                        return;
                    }
                    buf.setsize(off);
                    source_name(se, true);
                }
                else if (s.ident == Id.basic_istream || s.ident == Id.basic_ostream || s.ident == Id.basic_iostream)
                {
                    /* Replace
                     * ::std::basic_istream<char,  std::char_traits<char> > with Si
                     * ::std::basic_ostream<char,  std::char_traits<char> > with So
                     * ::std::basic_iostream<char, std::char_traits<char> > with Sd
                     */
                    size_t off = buf.offset;
                    components_on = false; // turn off substitutions
                    source_name(se, true);
                    components_on = true;
                    //printf("xx: '%.*s'\n", (int)(buf.offset - off), buf.data + off);
                    if (buf.offset - off >= 21 && memcmp(buf.data + off, "IcSt11char_traitsIcEE".ptr, 21) == 0)
                    {
                        buf.remove(off, 21);
                        char[2] mbuf;
                        mbuf[0] = 'S';
                        mbuf[1] = 'i';
                        if (s.ident == Id.basic_ostream)
                            mbuf[1] = 'o';
                        else if (s.ident == Id.basic_iostream)
                            mbuf[1] = 'd';
                        buf.insert(off, mbuf[]);
                        return;
                    }
                    buf.setsize(off);
                    buf.writestring("St");
                    source_name(se);
                }
                else
                {
                    buf.writestring("St");
                    source_name(se);
                }
            }
            else
            {
                buf.writeByte('N');
                if (!dont_write_prefix)
                    prefix_name(p);
                source_name(se);
                buf.writeByte('E');
            }
        }
        else
            source_name(se);
        store(s);
    }

    void mangle_variable(VarDeclaration d, bool is_temp_arg_ref)
    {
        // fake mangling for fields to fix https://issues.dlang.org/show_bug.cgi?id=16525
        if (!(d.storage_class & (STCextern | STCfield | STCgshared)))
        {
            d.error("Internal Compiler Error: C++ static non- __gshared non-extern variables not supported");
            fatal();
        }
        Dsymbol p = d.toParent();
        if (p && !p.isModule()) //for example: char Namespace1::beta[6] should be mangled as "_ZN10Namespace14betaE"
        {
            buf.writestring("_ZN");
            prefix_name(p);
            source_name(d);
            buf.writeByte('E');
        }
        else //char beta[6] should mangle as "beta"
        {
            if (!is_temp_arg_ref)
            {
                buf.writestring(d.ident.toChars());
            }
            else
            {
                buf.writestring("_Z");
                source_name(d);
            }
        }
    }

    void mangle_function(FuncDeclaration d)
    {
        //printf("mangle_function(%s)\n", d.toChars());
        /*
         * <mangled-name> ::= _Z <encoding>
         * <encoding> ::= <function name> <bare-function-type>
         *         ::= <data name>
         *         ::= <special-name>
         */
        TypeFunction tf = cast(TypeFunction)d.type;
        buf.writestring("_Z");
        Dsymbol p = d.toParent();
        TemplateDeclaration ftd = getFuncTemplateDecl(d);

        if (p && !p.isModule() && tf.linkage == LINKcpp && !ftd)
        {
            buf.writeByte('N');
            if (d.type.isConst())
                buf.writeByte('K');
            prefix_name(p);
            // See ABI 5.1.8 Compression
            // Replace ::std::allocator with Sa
            if (buf.offset >= 17 && memcmp(buf.data, "_ZN3std9allocator".ptr, 17) == 0)
            {
                buf.remove(3, 14);
                buf.insert(3, "Sa");
            }
            // Replace ::std::basic_string with Sb
            if (buf.offset >= 21 && memcmp(buf.data, "_ZN3std12basic_string".ptr, 21) == 0)
            {
                buf.remove(3, 18);
                buf.insert(3, "Sb");
            }
            // Replace ::std with St
            if (buf.offset >= 7 && memcmp(buf.data, "_ZN3std".ptr, 7) == 0)
            {
                buf.remove(3, 4);
                buf.insert(3, "St");
            }
            if (buf.offset >= 8 && memcmp(buf.data, "_ZNK3std".ptr, 8) == 0)
            {
                buf.remove(4, 4);
                buf.insert(4, "St");
            }
            if (d.isDtorDeclaration())
            {
                buf.writestring("D1");
            }
            else
            {
                source_name(d);
            }
            buf.writeByte('E');
        }
        else if (ftd)
        {
            source_name(p);
            this.is_top_level = true;
            tf.nextOf().accept(this);
            this.is_top_level = false;
        }
        else
        {
            source_name(d);
        }
        if (tf.linkage == LINKcpp) //Template args accept extern "C" symbols with special mangling
        {
            assert(tf.ty == Tfunction);
            argsCppMangle(tf.parameters, tf.varargs);
        }
    }

    void argsCppMangle(Parameters* parameters, int varargs)
    {
        int paramsCppMangleDg(size_t n, Parameter fparam)
        {
            Type t = fparam.type.merge2();
            if (fparam.storageClass & (STCout | STCref))
                t = t.referenceTo();
            else if (fparam.storageClass & STClazy)
            {
                // Mangle as delegate
                Type td = new TypeFunction(null, t, 0, LINKd);
                td = new TypeDelegate(td);
                t = merge(t);
            }
            if (t.ty == Tsarray)
            {
                // Mangle static arrays as pointers
                t.error(Loc(), "Internal Compiler Error: unable to pass static array to extern(C++) function.");
                t.error(Loc(), "Use pointer instead.");
                fatal();
                //t = t.nextOf().pointerTo();
            }
            /* If it is a basic, enum or struct type,
             * then don't mark it const
             */
            this.is_top_level = true;
            if ((t.ty == Tenum || t.ty == Tstruct || t.ty == Tpointer || t.isTypeBasic()) && t.isConst())
                t.mutableOf().accept(this);
            else
                t.accept(this);
            this.is_top_level = false;
            return 0;
        }

        if (parameters)
            Parameter._foreach(parameters, &paramsCppMangleDg);
        if (varargs)
            buf.writestring("z");
        else if (!parameters || !parameters.dim)
            buf.writeByte('v'); // encode ( ) parameters
    }

public:
    extern (D) this()
    {
        this.components_on = true;
    }

    const(char)* mangleOf(Dsymbol s)
    {
        VarDeclaration vd = s.isVarDeclaration();
        FuncDeclaration fd = s.isFuncDeclaration();
        if (vd)
        {
            mangle_variable(vd, false);
        }
        else if (fd)
        {
            mangle_function(fd);
        }
        else
        {
            assert(0);
        }
        Target.prefixName(&buf, LINKcpp);
        return buf.extractString();
    }

    override void visit(Type t)
    {
        if (t.isImmutable() || t.isShared())
        {
            t.error(Loc(), "Internal Compiler Error: shared or immutable types can not be mapped to C++ (%s)", t.toChars());
        }
        else
        {
            t.error(Loc(), "Internal Compiler Error: type %s can not be mapped to C++\n", t.toChars());
        }
        fatal(); //Fatal, because this error should be handled in frontend
    }

    override void visit(TypeBasic t)
    {
        /* ABI spec says:
         * v        void
         * w        wchar_t
         * b        bool
         * c        char
         * a        signed char
         * h        unsigned char
         * s        short
         * t        unsigned short
         * i        int
         * j        unsigned int
         * l        long
         * m        unsigned long
         * x        long long, __int64
         * y        unsigned long long, __int64
         * n        __int128
         * o        unsigned __int128
         * f        float
         * d        double
         * e        long double, __float80
         * g        __float128
         * z        ellipsis
         * u <source-name>  # vendor extended type
         */
        char c;
        char p = 0;
        switch (t.ty)
        {
        case Tvoid:
            c = 'v';
            break;
        case Tint8:
            c = 'a';
            break;
        case Tuns8:
            c = 'h';
            break;
        case Tint16:
            c = 's';
            break;
        case Tuns16:
            c = 't';
            break;
        case Tint32:
            c = 'i';
            break;
        case Tuns32:
            c = 'j';
            break;
        case Tfloat32:
            c = 'f';
            break;
        case Tint64:
            c = (Target.c_longsize == 8 ? 'l' : 'x');
            break;
        case Tuns64:
            c = (Target.c_longsize == 8 ? 'm' : 'y');
            break;
        case Tint128:
            c = 'n';
            break;
        case Tuns128:
            c = 'o';
            break;
        case Tfloat64:
            c = 'd';
            break;
        case Tfloat80:
            c = 'e';
            break;
        case Tbool:
            c = 'b';
            break;
        case Tchar:
            c = 'c';
            break;
        case Twchar:
            c = 't';
            break;
            // unsigned short
        case Tdchar:
            c = 'w';
            break;
            // wchar_t (UTF-32)
        case Timaginary32:
            p = 'G';
            c = 'f';
            break;
        case Timaginary64:
            p = 'G';
            c = 'd';
            break;
        case Timaginary80:
            p = 'G';
            c = 'e';
            break;
        case Tcomplex32:
            p = 'C';
            c = 'f';
            break;
        case Tcomplex64:
            p = 'C';
            c = 'd';
            break;
        case Tcomplex80:
            p = 'C';
            c = 'e';
            break;
        default:
            visit(cast(Type)t);
            return;
        }
        if (t.isImmutable() || t.isShared())
        {
            visit(cast(Type)t);
        }
        if (p || t.isConst())
        {
            if (substitute(t))
            {
                return;
            }
            else
            {
                store(t);
            }
        }
        if (t.isConst())
            buf.writeByte('K');

        // Handle any target-specific basic types.
        if (auto tm = Target.cppTypeMangle(t))
        {
            buf.writestring(tm);
        }
        else
        {
            if (p)
                buf.writeByte(p);
            buf.writeByte(c);
        }
    }

    override void visit(TypeVector t)
    {
        is_top_level = false;
        if (substitute(t))
            return;
        store(t);
        if (t.isImmutable() || t.isShared())
        {
            visit(cast(Type)t);
        }
        if (t.isConst())
            buf.writeByte('K');

        // Handle any target-specific vector types.
        if (auto tm = Target.cppTypeMangle(t))
        {
            buf.writestring(tm);
        }
        else
        {
            assert(t.basetype && t.basetype.ty == Tsarray);
            assert((cast(TypeSArray)t.basetype).dim);
            //buf.printf("Dv%llu_", ((TypeSArray *)t.basetype).dim.toInteger());// -- Gnu ABI v.4
            buf.writestring("U8__vector"); //-- Gnu ABI v.3
            t.basetype.nextOf().accept(this);
        }
    }

    override void visit(TypeSArray t)
    {
        is_top_level = false;
        if (!substitute(t))
            store(t);
        if (t.isImmutable() || t.isShared())
        {
            visit(cast(Type)t);
        }
        if (t.isConst())
            buf.writeByte('K');
        buf.printf("A%llu_", t.dim ? t.dim.toInteger() : 0);
        t.next.accept(this);
    }

    override void visit(TypeDArray t)
    {
        visit(cast(Type)t);
    }

    override void visit(TypeAArray t)
    {
        visit(cast(Type)t);
    }

    override void visit(TypePointer t)
    {
        is_top_level = false;
        if (substitute(t))
            return;
        if (t.isImmutable() || t.isShared())
        {
            visit(cast(Type)t);
        }
        if (t.isConst())
            buf.writeByte('K');
        buf.writeByte('P');
        t.next.accept(this);
        store(t);
    }

    override void visit(TypeReference t)
    {
        is_top_level = false;
        if (substitute(t))
            return;
        buf.writeByte('R');
        t.next.accept(this);
        store(t);
    }

    override void visit(TypeFunction t)
    {
        is_top_level = false;
        /*
         *  <function-type> ::= F [Y] <bare-function-type> E
         *  <bare-function-type> ::= <signature type>+
         *  # types are possible return type, then parameter types
         */
        /* ABI says:
            "The type of a non-static member function is considered to be different,
            for the purposes of substitution, from the type of a namespace-scope or
            static member function whose type appears similar. The types of two
            non-static member functions are considered to be different, for the
            purposes of substitution, if the functions are members of different
            classes. In other words, for the purposes of substitution, the class of
            which the function is a member is considered part of the type of
            function."

            BUG: Right now, types of functions are never merged, so our simplistic
            component matcher always finds them to be different.
            We should use Type.equals on these, and use different
            TypeFunctions for non-static member functions, and non-static
            member functions of different classes.
         */
        if (substitute(t))
            return;
        buf.writeByte('F');
        if (t.linkage == LINKc)
            buf.writeByte('Y');
        Type tn = t.next;
        if (t.isref)
            tn = tn.referenceTo();
        tn.accept(this);
        argsCppMangle(t.parameters, t.varargs);
        buf.writeByte('E');
        store(t);
    }

    override void visit(TypeDelegate t)
    {
        visit(cast(Type)t);
    }

    override void visit(TypeStruct t)
    {
        const id = t.sym.ident;
        //printf("struct id = '%s'\n", id.toChars());
        char c;
        if (id == Id.__c_long)
            c = 'l';
        else if (id == Id.__c_ulong)
            c = 'm';
        else
            c = 0;
        if (c)
        {
            if (t.isImmutable() || t.isShared())
            {
                visit(cast(Type)t);
            }
            if (t.isConst())
            {
                if (substitute(t))
                {
                    return;
                }
                else
                {
                    store(t);
                }
            }
            if (t.isConst())
                buf.writeByte('K');
            buf.writeByte(c);
            return;
        }
        is_top_level = false;
        if (substitute(t))
            return;
        if (t.isImmutable() || t.isShared())
        {
            visit(cast(Type)t);
        }
        if (t.isConst())
            buf.writeByte('K');

        // Handle any target-specific struct types.
        if (auto tm = Target.cppTypeMangle(t))
        {
            buf.writestring(tm);
        }
        else
        {
            if (!substitute(t.sym))
            {
                cpp_mangle_name(t.sym, t.isConst());
            }
            if (t.isImmutable() || t.isShared())
            {
                visit(cast(Type)t);
            }
        }
        if (t.isConst())
            store(t);
    }

    override void visit(TypeEnum t)
    {
        is_top_level = false;
        if (substitute(t))
            return;
        if (t.isConst())
            buf.writeByte('K');
        if (!substitute(t.sym))
        {
            cpp_mangle_name(t.sym, t.isConst());
        }
        if (t.isImmutable() || t.isShared())
        {
            visit(cast(Type)t);
        }
        if (t.isConst())
            store(t);
    }

    override void visit(TypeClass t)
    {
        if (substitute(t))
            return;
        if (t.isImmutable() || t.isShared())
        {
            visit(cast(Type)t);
        }
        if (t.isConst() && !is_top_level)
            buf.writeByte('K');
        is_top_level = false;
        buf.writeByte('P');
        if (t.isConst())
            buf.writeByte('K');
        if (!substitute(t.sym))
        {
            cpp_mangle_name(t.sym, t.isConst());
        }
        if (t.isConst())
            store(null);
        store(t);
    }

    final const(char)* mangle_typeinfo(Dsymbol s)
    {
        buf.writestring("_ZTI");
        cpp_mangle_name(s, false);
        return buf.extractString();
    }
}

extern (C++) const(char)* toCppMangleItanium(Dsymbol s)
{
    //printf("toCppMangleItanium(%s)\n", s.toChars());
    scope CppMangleVisitor v = new CppMangleVisitor();
    return v.mangleOf(s);
}

extern (C++) const(char)* cppTypeInfoMangleItanium(Dsymbol s)
{
    //printf("cppTypeInfoMangle(%s)\n", s.toChars());
    scope CppMangleVisitor v = new CppMangleVisitor();
    return v.mangle_typeinfo(s);
}

// Windows DMC and Microsoft Visual C++ mangling
enum VC_SAVED_TYPE_CNT = 10u;
enum VC_SAVED_IDENT_CNT = 10u;

extern (C++) final class VisualCPPMangler : Visitor
{
    alias visit = super.visit;
    const(char)*[VC_SAVED_IDENT_CNT] saved_idents;
    Type[VC_SAVED_TYPE_CNT] saved_types;

    // IS_NOT_TOP_TYPE: when we mangling one argument, we can call visit several times (for base types of arg type)
    // but we must save only arg type:
    // For example: if we have an int** argument, we should save "int**" but visit will be called for "int**", "int*", "int"
    // This flag is set up by the visit(NextType, ) function  and should be reset when the arg type output is finished.
    // MANGLE_RETURN_TYPE: return type shouldn't be saved and substituted in arguments
    // IGNORE_CONST: in some cases we should ignore CV-modifiers.

    enum Flags : int
    {
        IS_NOT_TOP_TYPE = 0x1,
        MANGLE_RETURN_TYPE = 0x2,
        IGNORE_CONST = 0x4,
        IS_DMC = 0x8,
    }

    alias IS_NOT_TOP_TYPE = Flags.IS_NOT_TOP_TYPE;
    alias MANGLE_RETURN_TYPE = Flags.MANGLE_RETURN_TYPE;
    alias IGNORE_CONST = Flags.IGNORE_CONST;
    alias IS_DMC = Flags.IS_DMC;

    int flags;
    OutBuffer buf;

    extern (D) this(VisualCPPMangler rvl)
    {
        flags |= (rvl.flags & IS_DMC);
        memcpy(&saved_idents, &rvl.saved_idents, (const(char)*).sizeof * VC_SAVED_IDENT_CNT);
        memcpy(&saved_types, &rvl.saved_types, Type.sizeof * VC_SAVED_TYPE_CNT);
    }

public:
    extern (D) this(bool isdmc)
    {
        if (isdmc)
        {
            flags |= IS_DMC;
        }
        memset(&saved_idents, 0, (const(char)*).sizeof * VC_SAVED_IDENT_CNT);
        memset(&saved_types, 0, Type.sizeof * VC_SAVED_TYPE_CNT);
    }

    override void visit(Type type)
    {
        if (type.isImmutable() || type.isShared())
        {
            type.error(Loc(), "Internal Compiler Error: shared or immutable types can not be mapped to C++ (%s)", type.toChars());
        }
        else
        {
            type.error(Loc(), "Internal Compiler Error: type %s can not be mapped to C++\n", type.toChars());
        }
        fatal(); //Fatal, because this error should be handled in frontend
    }

    override void visit(TypeBasic type)
    {
        //printf("visit(TypeBasic); is_not_top_type = %d\n", (int)(flags & IS_NOT_TOP_TYPE));
        if (type.isImmutable() || type.isShared())
        {
            visit(cast(Type)type);
            return;
        }
        if (type.isConst() && ((flags & IS_NOT_TOP_TYPE) || (flags & IS_DMC)))
        {
            if (checkTypeSaved(type))
                return;
        }
        if ((type.ty == Tbool) && checkTypeSaved(type)) // try to replace long name with number
        {
            return;
        }
        if (!(flags & IS_DMC))
        {
            switch (type.ty)
            {
            case Tint64:
            case Tuns64:
            case Tint128:
            case Tuns128:
            case Tfloat80:
            case Twchar:
                if (checkTypeSaved(type))
                    return;
                break;

            default:
                break;
            }
        }
        mangleModifier(type);
        switch (type.ty)
        {
        case Tvoid:
            buf.writeByte('X');
            break;
        case Tint8:
            buf.writeByte('C');
            break;
        case Tuns8:
            buf.writeByte('E');
            break;
        case Tint16:
            buf.writeByte('F');
            break;
        case Tuns16:
            buf.writeByte('G');
            break;
        case Tint32:
            buf.writeByte('H');
            break;
        case Tuns32:
            buf.writeByte('I');
            break;
        case Tfloat32:
            buf.writeByte('M');
            break;
        case Tint64:
            buf.writestring("_J");
            break;
        case Tuns64:
            buf.writestring("_K");
            break;
        case Tint128:
            buf.writestring("_L");
            break;
        case Tuns128:
            buf.writestring("_M");
            break;
        case Tfloat64:
            buf.writeByte('N');
            break;
        case Tbool:
            buf.writestring("_N");
            break;
        case Tchar:
            buf.writeByte('D');
            break;
        case Tdchar:
            buf.writeByte('I');
            break;
            // unsigned int
        case Tfloat80:
            if (flags & IS_DMC)
                buf.writestring("_Z"); // DigitalMars long double
            else
                buf.writestring("_T"); // Intel long double
            break;
        case Twchar:
            if (flags & IS_DMC)
                buf.writestring("_Y"); // DigitalMars wchar_t
            else
                buf.writestring("_W"); // Visual C++ wchar_t
            break;
        default:
            visit(cast(Type)type);
            return;
        }
        flags &= ~IS_NOT_TOP_TYPE;
        flags &= ~IGNORE_CONST;
    }

    override void visit(TypeVector type)
    {
        //printf("visit(TypeVector); is_not_top_type = %d\n", (int)(flags & IS_NOT_TOP_TYPE));
        if (checkTypeSaved(type))
            return;
        buf.writestring("T__m128@@"); // may be better as __m128i or __m128d?
        flags &= ~IS_NOT_TOP_TYPE;
        flags &= ~IGNORE_CONST;
    }

    override void visit(TypeSArray type)
    {
        // This method can be called only for static variable type mangling.
        //printf("visit(TypeSArray); is_not_top_type = %d\n", (int)(flags & IS_NOT_TOP_TYPE));
        if (checkTypeSaved(type))
            return;
        // first dimension always mangled as const pointer
        if (flags & IS_DMC)
            buf.writeByte('Q');
        else
            buf.writeByte('P');
        flags |= IS_NOT_TOP_TYPE;
        assert(type.next);
        if (type.next.ty == Tsarray)
        {
            mangleArray(cast(TypeSArray)type.next);
        }
        else
        {
            type.next.accept(this);
        }
    }

    // attention: D int[1][2]* arr mapped to C++ int arr[][2][1]; (because it's more typical situation)
    // There is not way to map int C++ (*arr)[2][1] to D
    override void visit(TypePointer type)
    {
        //printf("visit(TypePointer); is_not_top_type = %d\n", (int)(flags & IS_NOT_TOP_TYPE));
        if (type.isImmutable() || type.isShared())
        {
            visit(cast(Type)type);
            return;
        }
        assert(type.next);
        if (type.next.ty == Tfunction)
        {
            const(char)* arg = mangleFunctionType(cast(TypeFunction)type.next); // compute args before checking to save; args should be saved before function type
            // If we've mangled this function early, previous call is meaningless.
            // However we should do it before checking to save types of function arguments before function type saving.
            // If this function was already mangled, types of all it arguments are save too, thus previous can't save
            // anything if function is saved.
            if (checkTypeSaved(type))
                return;
            if (type.isConst())
                buf.writeByte('Q'); // const
            else
                buf.writeByte('P'); // mutable
            buf.writeByte('6'); // pointer to a function
            buf.writestring(arg);
            flags &= ~IS_NOT_TOP_TYPE;
            flags &= ~IGNORE_CONST;
            return;
        }
        else if (type.next.ty == Tsarray)
        {
            if (checkTypeSaved(type))
                return;
            mangleModifier(type);
            if (type.isConst() || !(flags & IS_DMC))
                buf.writeByte('Q'); // const
            else
                buf.writeByte('P'); // mutable
            if (global.params.is64bit)
                buf.writeByte('E');
            flags |= IS_NOT_TOP_TYPE;
            mangleArray(cast(TypeSArray)type.next);
            return;
        }
        else
        {
            if (checkTypeSaved(type))
                return;
            mangleModifier(type);
            if (type.isConst())
            {
                buf.writeByte('Q'); // const
            }
            else
            {
                buf.writeByte('P'); // mutable
            }
            if (global.params.is64bit)
                buf.writeByte('E');
            flags |= IS_NOT_TOP_TYPE;
            type.next.accept(this);
        }
    }

    override void visit(TypeReference type)
    {
        //printf("visit(TypeReference); type = %s\n", type.toChars());
        if (checkTypeSaved(type))
            return;
        if (type.isImmutable() || type.isShared())
        {
            visit(cast(Type)type);
            return;
        }
        buf.writeByte('A'); // mutable
        if (global.params.is64bit)
            buf.writeByte('E');
        flags |= IS_NOT_TOP_TYPE;
        assert(type.next);
        if (type.next.ty == Tsarray)
        {
            mangleArray(cast(TypeSArray)type.next);
        }
        else
        {
            type.next.accept(this);
        }
    }

    override void visit(TypeFunction type)
    {
        const(char)* arg = mangleFunctionType(type);
        if ((flags & IS_DMC))
        {
            if (checkTypeSaved(type))
                return;
        }
        else
        {
            buf.writestring("$$A6");
        }
        buf.writestring(arg);
        flags &= ~(IS_NOT_TOP_TYPE | IGNORE_CONST);
    }

    override void visit(TypeStruct type)
    {
        const id = type.sym.ident;
        char c;
        if (id == Id.__c_long_double)
            c = 'O'; // VC++ long double
        else if (id == Id.__c_long)
            c = 'J'; // VC++ long
        else if (id == Id.__c_ulong)
            c = 'K'; // VC++ unsigned long
        else
            c = 0;
        if (c)
        {
            if (type.isImmutable() || type.isShared())
            {
                visit(cast(Type)type);
                return;
            }
            if (type.isConst() && ((flags & IS_NOT_TOP_TYPE) || (flags & IS_DMC)))
            {
                if (checkTypeSaved(type))
                    return;
            }
            mangleModifier(type);
            buf.writeByte(c);
        }
        else
        {
            if (checkTypeSaved(type))
                return;
            //printf("visit(TypeStruct); is_not_top_type = %d\n", (int)(flags & IS_NOT_TOP_TYPE));
            mangleModifier(type);
            if (type.sym.isUnionDeclaration())
                buf.writeByte('T');
            else
                buf.writeByte(type.cppmangle == CPPMANGLE.asClass ? 'V' : 'U');
            mangleIdent(type.sym);
        }
        flags &= ~IS_NOT_TOP_TYPE;
        flags &= ~IGNORE_CONST;
    }

    override void visit(TypeEnum type)
    {
        //printf("visit(TypeEnum); is_not_top_type = %d\n", (int)(flags & IS_NOT_TOP_TYPE));
        if (checkTypeSaved(type))
            return;
        mangleModifier(type);
        buf.writeByte('W');
        switch (type.sym.memtype.ty)
        {
        case Tchar:
        case Tint8:
            buf.writeByte('0');
            break;
        case Tuns8:
            buf.writeByte('1');
            break;
        case Tint16:
            buf.writeByte('2');
            break;
        case Tuns16:
            buf.writeByte('3');
            break;
        case Tint32:
            buf.writeByte('4');
            break;
        case Tuns32:
            buf.writeByte('5');
            break;
        case Tint64:
            buf.writeByte('6');
            break;
        case Tuns64:
            buf.writeByte('7');
            break;
        default:
            visit(cast(Type)type);
            break;
        }
        mangleIdent(type.sym);
        flags &= ~IS_NOT_TOP_TYPE;
        flags &= ~IGNORE_CONST;
    }

    // D class mangled as pointer to C++ class
    // const(Object) mangled as Object const* const
    override void visit(TypeClass type)
    {
        //printf("visit(TypeClass); is_not_top_type = %d\n", (int)(flags & IS_NOT_TOP_TYPE));
        if (checkTypeSaved(type))
            return;
        if (flags & IS_NOT_TOP_TYPE)
            mangleModifier(type);
        if (type.isConst())
            buf.writeByte('Q');
        else
            buf.writeByte('P');
        if (global.params.is64bit)
            buf.writeByte('E');
        flags |= IS_NOT_TOP_TYPE;
        mangleModifier(type);
        buf.writeByte(type.cppmangle == CPPMANGLE.asStruct ? 'U' : 'V');
        mangleIdent(type.sym);
        flags &= ~IS_NOT_TOP_TYPE;
        flags &= ~IGNORE_CONST;
    }

    const(char)* mangleOf(Dsymbol s)
    {
        VarDeclaration vd = s.isVarDeclaration();
        FuncDeclaration fd = s.isFuncDeclaration();
        if (vd)
        {
            mangleVariable(vd);
        }
        else if (fd)
        {
            mangleFunction(fd);
        }
        else
        {
            assert(0);
        }
        return buf.extractString();
    }

private:
    void mangleFunction(FuncDeclaration d)
    {
        // <function mangle> ? <qualified name> <flags> <return type> <arg list>
        assert(d);
        buf.writeByte('?');
        mangleIdent(d);
        if (d.needThis()) // <flags> ::= <virtual/protection flag> <const/volatile flag> <calling convention flag>
        {
            // Pivate methods always non-virtual in D and it should be mangled as non-virtual in C++
            //printf("%s: isVirtualMethod = %d, isVirtual = %d, vtblIndex = %d, interfaceVirtual = %p\n",
                //d.toChars(), d.isVirtualMethod(), d.isVirtual(), cast(int)d.vtblIndex, d.interfaceVirtual);
            if (d.isVirtual() && (d.vtblIndex != -1 || d.interfaceVirtual || d.overrideInterface()))
            {
                switch (d.protection.kind)
                {
                case PROTprivate:
                    buf.writeByte('E');
                    break;
                case PROTprotected:
                    buf.writeByte('M');
                    break;
                default:
                    buf.writeByte('U');
                    break;
                }
            }
            else
            {
                switch (d.protection.kind)
                {
                case PROTprivate:
                    buf.writeByte('A');
                    break;
                case PROTprotected:
                    buf.writeByte('I');
                    break;
                default:
                    buf.writeByte('Q');
                    break;
                }
            }
            if (global.params.is64bit)
                buf.writeByte('E');
            if (d.type.isConst())
            {
                buf.writeByte('B');
            }
            else
            {
                buf.writeByte('A');
            }
        }
        else if (d.isMember2()) // static function
        {
            // <flags> ::= <virtual/protection flag> <calling convention flag>
            switch (d.protection.kind)
            {
            case PROTprivate:
                buf.writeByte('C');
                break;
            case PROTprotected:
                buf.writeByte('K');
                break;
            default:
                buf.writeByte('S');
                break;
            }
        }
        else // top-level function
        {
            // <flags> ::= Y <calling convention flag>
            buf.writeByte('Y');
        }
        const(char)* args = mangleFunctionType(cast(TypeFunction)d.type, d.needThis(), d.isCtorDeclaration() || d.isDtorDeclaration());
        buf.writestring(args);
    }

    void mangleVariable(VarDeclaration d)
    {
        // <static variable mangle> ::= ? <qualified name> <protection flag> <const/volatile flag> <type>
        assert(d);
        // fake mangling for fields to fix https://issues.dlang.org/show_bug.cgi?id=16525
        if (!(d.storage_class & (STCextern | STCfield | STCgshared)))
        {
            d.error("Internal Compiler Error: C++ static non- __gshared non-extern variables not supported");
            fatal();
        }
        buf.writeByte('?');
        mangleIdent(d);
        assert((d.storage_class & STCfield) || !d.needThis());
        Dsymbol parent = d.toParent();
        while (parent && parent.isNspace())
        {
            parent = parent.toParent();
        }
        if (parent && parent.isModule()) // static member
        {
            buf.writeByte('3');
        }
        else
        {
            switch (d.protection.kind)
            {
            case PROTprivate:
                buf.writeByte('0');
                break;
            case PROTprotected:
                buf.writeByte('1');
                break;
            default:
                buf.writeByte('2');
                break;
            }
        }
        char cv_mod = 0;
        Type t = d.type;
        if (t.isImmutable() || t.isShared())
        {
            visit(t);
            return;
        }
        if (t.isConst())
        {
            cv_mod = 'B'; // const
        }
        else
        {
            cv_mod = 'A'; // mutable
        }
        if (t.ty != Tpointer)
            t = t.mutableOf();
        t.accept(this);
        if ((t.ty == Tpointer || t.ty == Treference || t.ty == Tclass) && global.params.is64bit)
        {
            buf.writeByte('E');
        }
        buf.writeByte(cv_mod);
    }

    void mangleName(Dsymbol sym, bool dont_use_back_reference = false)
    {
        //printf("mangleName('%s')\n", sym.toChars());
        const(char)* name = null;
        bool is_dmc_template = false;
        if (sym.isDtorDeclaration())
        {
            buf.writestring("?1");
            return;
        }
        if (TemplateInstance ti = sym.isTemplateInstance())
        {
            scope VisualCPPMangler tmp = new VisualCPPMangler((flags & IS_DMC) ? true : false);
            tmp.buf.writeByte('?');
            tmp.buf.writeByte('$');
            tmp.buf.writestring(ti.name.toChars());
            tmp.saved_idents[0] = ti.name.toChars();
            tmp.buf.writeByte('@');
            if (flags & IS_DMC)
            {
                tmp.mangleIdent(sym.parent, true);
                is_dmc_template = true;
            }
            bool is_var_arg = false;
            for (size_t i = 0; i < ti.tiargs.dim; i++)
            {
                RootObject o = (*ti.tiargs)[i];
                TemplateParameter tp = null;
                TemplateValueParameter tv = null;
                TemplateTupleParameter tt = null;
                if (!is_var_arg)
                {
                    TemplateDeclaration td = ti.tempdecl.isTemplateDeclaration();
                    assert(td);
                    tp = (*td.parameters)[i];
                    tv = tp.isTemplateValueParameter();
                    tt = tp.isTemplateTupleParameter();
                }
                if (tt)
                {
                    is_var_arg = true;
                    tp = null;
                }
                if (tv)
                {
                    if (tv.valType.isintegral())
                    {
                        tmp.buf.writeByte('$');
                        tmp.buf.writeByte('0');
                        Expression e = isExpression(o);
                        assert(e);
                        if (tv.valType.isunsigned())
                        {
                            tmp.mangleNumber(e.toUInteger());
                        }
                        else if (is_dmc_template)
                        {
                            // NOTE: DMC mangles everything based on
                            // unsigned int
                            tmp.mangleNumber(e.toInteger());
                        }
                        else
                        {
                            sinteger_t val = e.toInteger();
                            if (val < 0)
                            {
                                val = -val;
                                tmp.buf.writeByte('?');
                            }
                            tmp.mangleNumber(val);
                        }
                    }
                    else
                    {
                        sym.error("Internal Compiler Error: C++ %s template value parameter is not supported", tv.valType.toChars());
                        fatal();
                    }
                }
                else if (!tp || tp.isTemplateTypeParameter())
                {
                    Type t = isType(o);
                    assert(t);
                    t.accept(tmp);
                }
                else if (tp.isTemplateAliasParameter())
                {
                    Dsymbol d = isDsymbol(o);
                    Expression e = isExpression(o);
                    if (!d && !e)
                    {
                        sym.error("Internal Compiler Error: %s is unsupported parameter for C++ template", o.toChars());
                        fatal();
                    }
                    if (d && d.isFuncDeclaration())
                    {
                        tmp.buf.writeByte('$');
                        tmp.buf.writeByte('1');
                        tmp.mangleFunction(d.isFuncDeclaration());
                    }
                    else if (e && e.op == TOKvar && (cast(VarExp)e).var.isVarDeclaration())
                    {
                        tmp.buf.writeByte('$');
                        if (flags & IS_DMC)
                            tmp.buf.writeByte('1');
                        else
                            tmp.buf.writeByte('E');
                        tmp.mangleVariable((cast(VarExp)e).var.isVarDeclaration());
                    }
                    else if (d && d.isTemplateDeclaration() && d.isTemplateDeclaration().onemember)
                    {
                        Dsymbol ds = d.isTemplateDeclaration().onemember;
                        if (flags & IS_DMC)
                        {
                            tmp.buf.writeByte('V');
                        }
                        else
                        {
                            if (ds.isUnionDeclaration())
                            {
                                tmp.buf.writeByte('T');
                            }
                            else if (ds.isStructDeclaration())
                            {
                                tmp.buf.writeByte('U');
                            }
                            else if (ds.isClassDeclaration())
                            {
                                tmp.buf.writeByte('V');
                            }
                            else
                            {
                                sym.error("Internal Compiler Error: C++ templates support only integral value, type parameters, alias templates and alias function parameters");
                                fatal();
                            }
                        }
                        tmp.mangleIdent(d);
                    }
                    else
                    {
                        sym.error("Internal Compiler Error: %s is unsupported parameter for C++ template: (%s)", o.toChars());
                        fatal();
                    }
                }
                else
                {
                    sym.error("Internal Compiler Error: C++ templates support only integral value, type parameters, alias templates and alias function parameters");
                    fatal();
                }
            }
            name = tmp.buf.extractString();
        }
        else
        {
            name = sym.ident.toChars();
        }
        assert(name);
        if (is_dmc_template)
        {
            if (checkAndSaveIdent(name))
                return;
        }
        else
        {
            if (dont_use_back_reference)
            {
                saveIdent(name);
            }
            else
            {
                if (checkAndSaveIdent(name))
                    return;
            }
        }
        buf.writestring(name);
        buf.writeByte('@');
    }

    // returns true if name already saved
    bool checkAndSaveIdent(const(char)* name)
    {
        foreach (i; 0 .. VC_SAVED_IDENT_CNT)
        {
            if (!saved_idents[i]) // no saved same name
            {
                saved_idents[i] = name;
                break;
            }
            if (!strcmp(saved_idents[i], name)) // ok, we've found same name. use index instead of name
            {
                buf.writeByte(i + '0');
                return true;
            }
        }
        return false;
    }

    void saveIdent(const(char)* name)
    {
        foreach (i; 0 .. VC_SAVED_IDENT_CNT)
        {
            if (!saved_idents[i]) // no saved same name
            {
                saved_idents[i] = name;
                break;
            }
            if (!strcmp(saved_idents[i], name)) // ok, we've found same name. use index instead of name
            {
                return;
            }
        }
    }

    void mangleIdent(Dsymbol sym, bool dont_use_back_reference = false)
    {
        // <qualified name> ::= <sub-name list> @
        // <sub-name list>  ::= <sub-name> <name parts>
        //                  ::= <sub-name>
        // <sub-name> ::= <identifier> @
        //            ::= ?$ <identifier> @ <template args> @
        //            :: <back reference>
        // <back reference> ::= 0-9
        // <template args> ::= <template arg> <template args>
        //                ::= <template arg>
        // <template arg>  ::= <type>
        //                ::= $0<encoded integral number>
        //printf("mangleIdent('%s')\n", sym.toChars());
        Dsymbol p = sym;
        if (p.toParent() && p.toParent().isTemplateInstance())
        {
            p = p.toParent();
        }
        while (p && !p.isModule())
        {
            mangleName(p, dont_use_back_reference);
            p = p.toParent();
            if (p.toParent() && p.toParent().isTemplateInstance())
            {
                p = p.toParent();
            }
        }
        if (!dont_use_back_reference)
            buf.writeByte('@');
    }

    void mangleNumber(dinteger_t num)
    {
        if (!num) // 0 encoded as "A@"
        {
            buf.writeByte('A');
            buf.writeByte('@');
            return;
        }
        if (num <= 10) // 5 encoded as "4"
        {
            buf.writeByte(cast(char)(num - 1 + '0'));
            return;
        }
        char[17] buff;
        buff[16] = 0;
        size_t i = 16;
        while (num)
        {
            --i;
            buff[i] = num % 16 + 'A';
            num /= 16;
        }
        buf.writestring(&buff[i]);
        buf.writeByte('@');
    }

    bool checkTypeSaved(Type type)
    {
        if (flags & IS_NOT_TOP_TYPE)
            return false;
        if (flags & MANGLE_RETURN_TYPE)
            return false;
        for (uint i = 0; i < VC_SAVED_TYPE_CNT; i++)
        {
            if (!saved_types[i]) // no saved same type
            {
                saved_types[i] = type;
                return false;
            }
            if (saved_types[i].equals(type)) // ok, we've found same type. use index instead of type
            {
                buf.writeByte(i + '0');
                flags &= ~IS_NOT_TOP_TYPE;
                flags &= ~IGNORE_CONST;
                return true;
            }
        }
        return false;
    }

    void mangleModifier(Type type)
    {
        if (flags & IGNORE_CONST)
            return;
        if (type.isImmutable() || type.isShared())
        {
            visit(type);
            return;
        }
        if (type.isConst())
        {
            if (flags & IS_NOT_TOP_TYPE)
                buf.writeByte('B'); // const
            else if ((flags & IS_DMC) && type.ty != Tpointer)
                buf.writestring("_O");
        }
        else if (flags & IS_NOT_TOP_TYPE)
            buf.writeByte('A'); // mutable
    }

    void mangleArray(TypeSArray type)
    {
        mangleModifier(type);
        size_t i = 0;
        Type cur = type;
        while (cur && cur.ty == Tsarray)
        {
            i++;
            cur = cur.nextOf();
        }
        buf.writeByte('Y');
        mangleNumber(i); // count of dimensions
        cur = type;
        while (cur && cur.ty == Tsarray) // sizes of dimensions
        {
            TypeSArray sa = cast(TypeSArray)cur;
            mangleNumber(sa.dim ? sa.dim.toInteger() : 0);
            cur = cur.nextOf();
        }
        flags |= IGNORE_CONST;
        cur.accept(this);
    }

    const(char)* mangleFunctionType(TypeFunction type, bool needthis = false, bool noreturn = false)
    {
        scope VisualCPPMangler tmp = new VisualCPPMangler(this);
        // Calling convention
        if (global.params.is64bit) // always Microsoft x64 calling convention
        {
            tmp.buf.writeByte('A');
        }
        else
        {
            switch (type.linkage)
            {
            case LINKc:
                tmp.buf.writeByte('A');
                break;
            case LINKcpp:
                if (needthis && type.varargs != 1)
                    tmp.buf.writeByte('E'); // thiscall
                else
                    tmp.buf.writeByte('A'); // cdecl
                break;
            case LINKwindows:
                tmp.buf.writeByte('G'); // stdcall
                break;
            case LINKpascal:
                tmp.buf.writeByte('C');
                break;
            default:
                tmp.visit(cast(Type)type);
                break;
            }
        }
        tmp.flags &= ~IS_NOT_TOP_TYPE;
        if (noreturn)
        {
            tmp.buf.writeByte('@');
        }
        else
        {
            Type rettype = type.next;
            if (type.isref)
                rettype = rettype.referenceTo();
            flags &= ~IGNORE_CONST;
            if (rettype.ty == Tstruct || rettype.ty == Tenum)
            {
                const id = rettype.toDsymbol(null).ident;
                if (id != Id.__c_long_double && id != Id.__c_long && id != Id.__c_ulong)
                {
                    tmp.buf.writeByte('?');
                    tmp.buf.writeByte('A');
                }
            }
            tmp.flags |= MANGLE_RETURN_TYPE;
            rettype.accept(tmp);
            tmp.flags &= ~MANGLE_RETURN_TYPE;
        }
        if (!type.parameters || !type.parameters.dim)
        {
            if (type.varargs == 1)
                tmp.buf.writeByte('Z');
            else
                tmp.buf.writeByte('X');
        }
        else
        {
            int mangleParameterDg(size_t n, Parameter p)
            {
                Type t = p.type;
                if (p.storageClass & (STCout | STCref))
                {
                    t = t.referenceTo();
                }
                else if (p.storageClass & STClazy)
                {
                    // Mangle as delegate
                    Type td = new TypeFunction(null, t, 0, LINKd);
                    td = new TypeDelegate(td);
                    t = merge(t);
                }
                if (t.ty == Tsarray)
                {
                    t.error(Loc(), "Internal Compiler Error: unable to pass static array to extern(C++) function.");
                    t.error(Loc(), "Use pointer instead.");
                    assert(0);
                }
                tmp.flags &= ~IS_NOT_TOP_TYPE;
                tmp.flags &= ~IGNORE_CONST;
                t.accept(tmp);
                return 0;
            }

            Parameter._foreach(type.parameters, &mangleParameterDg);
            if (type.varargs == 1)
            {
                tmp.buf.writeByte('Z');
            }
            else
            {
                tmp.buf.writeByte('@');
            }
        }
        tmp.buf.writeByte('Z');
        const(char)* ret = tmp.buf.extractString();
        memcpy(&saved_idents, &tmp.saved_idents, (const(char)*).sizeof * VC_SAVED_IDENT_CNT);
        memcpy(&saved_types, &tmp.saved_types, Type.sizeof * VC_SAVED_TYPE_CNT);
        return ret;
    }
}

extern (C++) const(char)* toCppMangleMSVC(Dsymbol s)
{
    scope VisualCPPMangler v = new VisualCPPMangler(!global.params.mscoff);
    return v.mangleOf(s);
}

extern (C++) const(char)* cppTypeInfoMangleMSVC(Dsymbol s)
{
    //printf("cppTypeInfoMangle(%s)\n", s.toChars());
    version (IN_LLVM)
    {
        // Return the mangled name of the RTTI Type Descriptor.
        // Reverse-engineered using a few C++ exception classes.
        scope VisualCPPMangler v = new VisualCPPMangler(!global.params.mscoff);
        v.buf.writestring("\1??_R0?AV");
        v.mangleIdent(s);
        v.buf.writestring("@8");
        return v.buf.extractString();
    }
    else
    {
        assert(0);
    }
}
