C++ DtBuilder类代码示例

        void visit(EnumDeclaration *ed)
        {
            if (ed->semanticRun >= PASSobj)  // already written
                return;
            //printf("EnumDeclaration::toObjFile('%s')\n", ed->toChars());

            if (ed->errors || ed->type->ty == Terror)
            {
                ed->error("had semantic errors when compiling");
                return;
            }

            if (ed->isAnonymous())
                return;

            if (global.params.symdebug)
                toDebug(ed);

            genTypeInfo(ed->type, NULL);

            TypeEnum *tc = (TypeEnum *)ed->type;
            if (!tc->sym->members || ed->type->isZeroInit())
                ;
            else
            {
                enum_SC scclass = SCglobal;
                if (ed->isInstantiated())
                    scclass = SCcomdat;

                // Generate static initializer
                toInitializer(ed);
                ed->sinit->Sclass = scclass;
                ed->sinit->Sfl = FLdata;
                DtBuilder dtb;
                Expression_toDt(tc->sym->defaultval, &dtb);
                ed->sinit->Sdt = dtb.finish();
                outdata(ed->sinit);
            }
            ed->semanticRun = PASSobj;
        }

void win64_pdata(Symbol *sf)
{
//    return; // doesn't work yet

    //printf("win64_pdata()\n");
    assert(config.exe == EX_WIN64);

    // Generate the pdata name, which is $pdata$funcname
    size_t sflen = strlen(sf->Sident);
    char *pdata_name = (char *)(sflen < ALLOCA_LIMIT ? alloca(7 + sflen + 1) : malloc(7 + sflen + 1));
    assert(pdata_name);
    memcpy(pdata_name, "$pdata$", 7);
    memcpy(pdata_name + 7, sf->Sident, sflen + 1);      // include terminating 0

    symbol *spdata = symbol_name(pdata_name,SCstatic,tsint);
    symbol_keep(spdata);
    symbol_debug(spdata);

    symbol *sunwind = win64_unwind(sf);

    /* 3 pointers are emitted:
     *  1. pointer to start of function sf
     *  2. pointer past end of function sf
     *  3. pointer to unwind data
     */

    DtBuilder dtb;
    dtb.xoff(sf,0,TYint);       // Note the TYint, these are 32 bit fixups
    dtb.xoff(sf,retoffset + retsize,TYint);
    dtb.xoff(sunwind,0,TYint);
    spdata->Sdt = dtb.finish();

    spdata->Sseg = symbol_iscomdat(sf) ? MsCoffObj::seg_pdata_comdat(sf) : MsCoffObj::seg_pdata();
    spdata->Salignment = 4;
    outdata(spdata);

    if (sflen >= ALLOCA_LIMIT) free(pdata_name);
}

        /**
         * Output a TLS symbol for Mach-O.
         *
         * A TLS variable in the Mach-O format consists of two symbols.
         * One symbol for the data, which contains the initializer, if any.
         * The name of this symbol is the same as the variable, but with the
         * "$tlv$init" suffix. If the variable has an initializer it's placed in
         * the __thread_data section. Otherwise it's placed in the __thread_bss
         * section.
         *
         * The other symbol is for the TLV descriptor. The symbol has the same
         * name as the variable and is placed in the __thread_vars section.
         * A TLV descriptor has the following structure, where T is the type of
         * the variable:
         *
         * struct TLVDescriptor(T)
         * {
         *     extern(C) T* function(TLVDescriptor*) thunk;
         *     size_t key;
         *     size_t offset;
         * }
         *
         * Input:
         *      vd  the variable declaration for the symbol
         *      s   the symbol to output
         */
        void tlsToDt(VarDeclaration *vd, Symbol *s, DtBuilder& dtb)
        {
            assert(config.objfmt == OBJ_MACH && I64 && (s->ty() & mTYLINK) == mTYthread);

            Symbol *tlvInit = createTLVDataSymbol(vd, s);
            DtBuilder tlvInitDtb;

            if (vd->_init)
                initializerToDt(vd, tlvInitDtb);
            else
                Type_toDt(vd->type, &tlvInitDtb);

            tlvInit->Sdt = tlvInitDtb.finish();
            outdata(tlvInit);

            if (I64)
                tlvInit->Sclass = SCextern;

            Symbol* tlvBootstrap = objmod->tlv_bootstrap();
            dtb.xoff(tlvBootstrap, 0, TYnptr);
            dtb.size(0);
            dtb.xoff(tlvInit, 0, TYnptr);
        }

void nteh_gentables(Symbol *sfunc)
{
    symbol *s = s_table;
    symbol_debug(s);
#if MARS
    //except_fillInEHTable(s);
#else
    /* NTEH table for C.
     * The table consists of triples:
     *  parent index
     *  filter address
     *  handler address
     */
    unsigned fsize = 4;             // target size of function pointer
    DtBuilder dtb;
    int sz = 0;                     // size so far

    for (block *b = startblock; b; b = b->Bnext)
    {
        if (b->BC == BC_try)
        {
            block *bhandler;

            dtb.dword(b->Blast_index);  // parent index

            // If try-finally
            if (b->numSucc() == 2)
            {
                dtb.dword(0);           // filter address
                bhandler = b->nthSucc(1);
                assert(bhandler->BC == BC_finally);
                // To successor of BC_finally block
                bhandler = bhandler->nthSucc(0);
            }
            else // try-except
            {
                bhandler = b->nthSucc(1);
                assert(bhandler->BC == BC_filter);
                dtb.coff(bhandler->Boffset);    // filter address
                bhandler = b->nthSucc(2);
                assert(bhandler->BC == BC_except);
            }
            dtb.coff(bhandler->Boffset);        // handler address
            sz += 4 + fsize * 2;
        }
    }
    assert(sz != 0);
    s->Sdt = dtb.finish();
#endif

    outdata(s);                 // output the scope table
#if MARS
    nteh_framehandler(sfunc, s);
#endif
    s_table = NULL;
}

void genModuleInfo(Module *m)
{
    //printf("Module::genmoduleinfo() %s\n", m->toChars());

    if (!Module::moduleinfo)
    {
        ObjectNotFound(Id::ModuleInfo);
    }

    Symbol *msym = toSymbol(m);

    //////////////////////////////////////////////

    m->csym->Sclass = SCglobal;
    m->csym->Sfl = FLdata;

    DtBuilder dtb;
    ClassDeclarations aclasses;

    //printf("members->dim = %d\n", members->dim);
    for (size_t i = 0; i < m->members->dim; i++)
    {
        Dsymbol *member = (*m->members)[i];

        //printf("\tmember '%s'\n", member->toChars());
        member->addLocalClass(&aclasses);
    }

    // importedModules[]
    size_t aimports_dim = m->aimports.dim;
    for (size_t i = 0; i < m->aimports.dim; i++)
    {
        Module *mod = m->aimports[i];
        if (!mod->needmoduleinfo)
            aimports_dim--;
    }

    FuncDeclaration *sgetmembers = m->findGetMembers();

    // These must match the values in druntime/src/object_.d
    #define MIstandalone      0x4
    #define MItlsctor         0x8
    #define MItlsdtor         0x10
    #define MIctor            0x20
    #define MIdtor            0x40
    #define MIxgetMembers     0x80
    #define MIictor           0x100
    #define MIunitTest        0x200
    #define MIimportedModules 0x400
    #define MIlocalClasses    0x800
    #define MIname            0x1000

    unsigned flags = 0;
    if (!m->needmoduleinfo)
        flags |= MIstandalone;
    if (m->sctor)
        flags |= MItlsctor;
    if (m->sdtor)
        flags |= MItlsdtor;
    if (m->ssharedctor)
        flags |= MIctor;
    if (m->sshareddtor)
        flags |= MIdtor;
    if (sgetmembers)
        flags |= MIxgetMembers;
    if (m->sictor)
        flags |= MIictor;
    if (m->stest)
        flags |= MIunitTest;
    if (aimports_dim)
        flags |= MIimportedModules;
    if (aclasses.dim)
        flags |= MIlocalClasses;
    flags |= MIname;

    dtb.dword(flags);        // _flags
    dtb.dword(0);            // _index

    if (flags & MItlsctor)
        dtb.xoff(m->sctor, 0, TYnptr);
    if (flags & MItlsdtor)
        dtb.xoff(m->sdtor, 0, TYnptr);
    if (flags & MIctor)
        dtb.xoff(m->ssharedctor, 0, TYnptr);
    if (flags & MIdtor)
        dtb.xoff(m->sshareddtor, 0, TYnptr);
    if (flags & MIxgetMembers)
        dtb.xoff(toSymbol(sgetmembers), 0, TYnptr);
    if (flags & MIictor)
        dtb.xoff(m->sictor, 0, TYnptr);
    if (flags & MIunitTest)
        dtb.xoff(m->stest, 0, TYnptr);
    if (flags & MIimportedModules)
    {
        dtb.size(aimports_dim);
        for (size_t i = 0; i < m->aimports.dim; i++)
        {
            Module *mod = m->aimports[i];

            if (!mod->needmoduleinfo)
//.........这里部分代码省略.........