Ejemplo n.º 1
0
bool alreadyOrWillBeDefined(FuncDeclaration &fdecl) {
  for (FuncDeclaration *f = &fdecl; f;) {
    if (!f->isInstantiated() && f->inNonRoot()) {
      return false;
    }
    if (f->isNested()) {
      f = f->toParent2()->isFuncDeclaration();
    } else {
      break;
    }
  }
  return true;
}
Ejemplo n.º 2
0
void DtoDefineFunction(FuncDeclaration* fd)
{
    IF_LOG Logger::println("DtoDefineFunction(%s): %s", fd->toPrettyChars(), fd->loc.toChars());
    LOG_SCOPE;

    if (fd->ir.isDefined()) return;

    if ((fd->type && fd->type->ty == Terror) ||
        (fd->type && fd->type->ty == Tfunction && static_cast<TypeFunction *>(fd->type)->next == NULL) ||
        (fd->type && fd->type->ty == Tfunction && static_cast<TypeFunction *>(fd->type)->next->ty == Terror))
    {
        IF_LOG Logger::println("Ignoring; has error type, no return type or returns error type");
        fd->ir.setDefined();
        return;
    }

    if (fd->semanticRun == PASSsemanticdone)
    {
        /* What happened is this function failed semantic3() with errors,
         * but the errors were gagged.
         * Try to reproduce those errors, and then fail.
         */
        error(fd->loc, "errors compiling function %s", fd->toPrettyChars());
        fd->ir.setDefined();
        return;
    }

    DtoResolveFunction(fd);

    if (fd->isUnitTestDeclaration() && !global.params.useUnitTests)
    {
        IF_LOG Logger::println("No code generation for unit test declaration %s", fd->toChars());
        fd->ir.setDefined();
        return;
    }

    // Skip array ops implemented in druntime
    if (fd->isArrayOp && isDruntimeArrayOp(fd))
    {
        IF_LOG Logger::println("No code generation for array op %s implemented in druntime", fd->toChars());
        fd->ir.setDefined();
        return;
    }

    // Check whether the frontend knows that the function is already defined
    // in some other module (see DMD's FuncDeclaration::toObjFile).
    for (FuncDeclaration *f = fd; f; )
    {
        if (!f->isInstantiated() && f->inNonRoot())
        {
            IF_LOG Logger::println("Skipping '%s'.", fd->toPrettyChars());
            // TODO: Emit as available_externally for inlining purposes instead
            // (see #673).
            fd->ir.setDefined();
            return;
        }
        if (f->isNested())
            f = f->toParent2()->isFuncDeclaration();
        else
            break;
    }

    DtoDeclareFunction(fd);
    assert(fd->ir.isDeclared());

    // DtoResolveFunction might also set the defined flag for functions we
    // should not touch.
    if (fd->ir.isDefined()) return;
    fd->ir.setDefined();

    // We cannot emit nested functions with parents that have not gone through
    // semantic analysis. This can happen as DMD leaks some template instances
    // from constraints into the module member list. DMD gets away with being
    // sloppy as functions in template contraints obviously never need to access
    // data from the template function itself, but it would still mess up our
    // nested context creation code.
    FuncDeclaration* parent = fd;
    while ((parent = getParentFunc(parent, true)))
    {
        if (parent->semanticRun != PASSsemantic3done || parent->semantic3Errors)
        {
            IF_LOG Logger::println("Ignoring nested function with unanalyzed parent.");
            return;
        }
    }

    assert(fd->semanticRun == PASSsemantic3done);
    assert(fd->ident != Id::empty);

    if (fd->isUnitTestDeclaration()) {
        gIR->unitTests.push_back(fd);
    } else if (fd->isSharedStaticCtorDeclaration()) {
        gIR->sharedCtors.push_back(fd);
    } else if (StaticDtorDeclaration *dtorDecl = fd->isSharedStaticDtorDeclaration()) {
        gIR->sharedDtors.push_front(fd);
        if (dtorDecl->vgate)
            gIR->sharedGates.push_front(dtorDecl->vgate);
    } else if (fd->isStaticCtorDeclaration()) {
        gIR->ctors.push_back(fd);
    } else if (StaticDtorDeclaration *dtorDecl = fd->isStaticDtorDeclaration()) {
        gIR->dtors.push_front(fd);
        if (dtorDecl->vgate)
            gIR->gates.push_front(dtorDecl->vgate);
    }


    // if this function is naked, we take over right away! no standard processing!
    if (fd->naked)
    {
        DtoDefineNakedFunction(fd);
        return;
    }

    IrFunction *irFunc = getIrFunc(fd);
    IrFuncTy &irFty = irFunc->irFty;

    // debug info
    irFunc->diSubprogram = gIR->DBuilder.EmitSubProgram(fd);

    Type* t = fd->type->toBasetype();
    TypeFunction* f = static_cast<TypeFunction*>(t);
    // assert(f->ctype);

    llvm::Function* func = irFunc->func;

    // is there a body?
    if (fd->fbody == NULL)
        return;

    IF_LOG Logger::println("Doing function body for: %s", fd->toChars());
    gIR->functions.push_back(irFunc);

    if (fd->isMain())
        gIR->emitMain = true;

    func->setLinkage(lowerFuncLinkage(fd));

    // On x86_64, always set 'uwtable' for System V ABI compatibility.
    // TODO: Find a better place for this.
    // TODO: Is this required for Win64 as well?
    if (global.params.targetTriple.getArch() == llvm::Triple::x86_64)
    {
        func->addFnAttr(LDC_ATTRIBUTE(UWTable));
    }
#if LDC_LLVM_VER >= 303
    if (opts::sanitize != opts::None) {
        // Set the required sanitizer attribute.
        if (opts::sanitize == opts::AddressSanitizer) {
            func->addFnAttr(LDC_ATTRIBUTE(SanitizeAddress));
        }

        if (opts::sanitize == opts::MemorySanitizer) {
            func->addFnAttr(LDC_ATTRIBUTE(SanitizeMemory));
        }

        if (opts::sanitize == opts::ThreadSanitizer) {
            func->addFnAttr(LDC_ATTRIBUTE(SanitizeThread));
        }
    }
#endif

    llvm::BasicBlock* beginbb = llvm::BasicBlock::Create(gIR->context(), "", func);
    llvm::BasicBlock* endbb = llvm::BasicBlock::Create(gIR->context(), "endentry", func);

    //assert(gIR->scopes.empty());
    gIR->scopes.push_back(IRScope(beginbb, endbb));

    // create alloca point
    // this gets erased when the function is complete, so alignment etc does not matter at all
    llvm::Instruction* allocaPoint = new llvm::AllocaInst(LLType::getInt32Ty(gIR->context()), "alloca point", beginbb);
    irFunc->allocapoint = allocaPoint;

    // debug info - after all allocas, but before any llvm.dbg.declare etc
    gIR->DBuilder.EmitFuncStart(fd);

    // this hack makes sure the frame pointer elimination optimization is disabled.
    // this this eliminates a bunch of inline asm related issues.
    if (fd->hasReturnExp & 8) // has inline asm
    {
        // emit a call to llvm_eh_unwind_init
        LLFunction* hack = GET_INTRINSIC_DECL(eh_unwind_init);
        gIR->ir->CreateCall(hack, "");
    }

    // give the 'this' argument storage and debug info
    if (irFty.arg_this)
    {
        LLValue* thisvar = irFunc->thisArg;
        assert(thisvar);

        LLValue* thismem = thisvar;
        if (!irFty.arg_this->byref)
        {
            thismem = DtoRawAlloca(thisvar->getType(), 0, "this"); // FIXME: align?
            DtoStore(thisvar, thismem);
            irFunc->thisArg = thismem;
        }

        assert(getIrParameter(fd->vthis)->value == thisvar);
        getIrParameter(fd->vthis)->value = thismem;

        gIR->DBuilder.EmitLocalVariable(thismem, fd->vthis);
    }

    // give the 'nestArg' storage
    if (irFty.arg_nest)
    {
        LLValue *nestArg = irFunc->nestArg;
        LLValue *val = DtoRawAlloca(nestArg->getType(), 0, "nestedFrame");
        DtoStore(nestArg, val);
        irFunc->nestArg = val;
    }

    // give arguments storage
    // and debug info
    if (fd->parameters)
    {
        size_t n = irFty.args.size();
        assert(n == fd->parameters->dim);
        for (size_t i=0; i < n; ++i)
        {
            Dsymbol* argsym = static_cast<Dsymbol*>(fd->parameters->data[i]);
            VarDeclaration* vd = argsym->isVarDeclaration();
            assert(vd);

            IrParameter* irparam = getIrParameter(vd);
            assert(irparam);

            bool refout = vd->storage_class & (STCref | STCout);
            bool lazy = vd->storage_class & STClazy;
            if (!refout && (!irparam->arg->byref || lazy))
            {
                // alloca a stack slot for this first class value arg
                LLValue* mem = DtoAlloca(irparam->arg->type, vd->ident->toChars());

                // let the abi transform the argument back first
                DImValue arg_dval(vd->type, irparam->value);
                irFty.getParam(vd->type, i, &arg_dval, mem);

                // set the arg var value to the alloca
                irparam->value = mem;
            }

            if (global.params.symdebug && !(isaArgument(irparam->value) && isaArgument(irparam->value)->hasByValAttr()) && !refout)
                gIR->DBuilder.EmitLocalVariable(irparam->value, vd);
        }
    }

    FuncGen fg;
    irFunc->gen = &fg;

    DtoCreateNestedContext(fd);

    if (fd->vresult && !
        fd->vresult->nestedrefs.dim // FIXME: not sure here :/
    )
    {
        DtoVarDeclaration(fd->vresult);
    }

    // D varargs: prepare _argptr and _arguments
    if (f->linkage == LINKd && f->varargs == 1)
    {
        // allocate _argptr (of type core.stdc.stdarg.va_list)
        LLValue* argptrmem = DtoAlloca(Type::tvalist, "_argptr_mem");
        irFunc->_argptr = argptrmem;

        // initialize _argptr with a call to the va_start intrinsic
        LLValue* vaStartArg = gABI->prepareVaStart(argptrmem);
        llvm::CallInst::Create(GET_INTRINSIC_DECL(vastart), vaStartArg, "", gIR->scopebb());

        // copy _arguments to a memory location
        LLType* argumentsType = irFunc->_arguments->getType();
        LLValue* argumentsmem = DtoRawAlloca(argumentsType, 0, "_arguments_mem");
        new llvm::StoreInst(irFunc->_arguments, argumentsmem, gIR->scopebb());
        irFunc->_arguments = argumentsmem;
    }

    // output function body
    codegenFunction(fd->fbody, gIR);
    irFunc->gen = 0;

    llvm::BasicBlock* bb = gIR->scopebb();
    if (pred_begin(bb) == pred_end(bb) && bb != &bb->getParent()->getEntryBlock()) {
        // This block is trivially unreachable, so just delete it.
        // (This is a common case because it happens when 'return'
        // is the last statement in a function)
        bb->eraseFromParent();
    } else if (!gIR->scopereturned()) {
        // llvm requires all basic blocks to end with a TerminatorInst but DMD does not put a return statement
        // in automatically, so we do it here.

        // pass the previous block into this block
        gIR->DBuilder.EmitFuncEnd(fd);
        if (func->getReturnType() == LLType::getVoidTy(gIR->context())) {
            llvm::ReturnInst::Create(gIR->context(), gIR->scopebb());
        }
        else if (!fd->isMain()) {
            AsmBlockStatement* asmb = fd->fbody->endsWithAsm();
            if (asmb) {
                assert(asmb->abiret);
                llvm::ReturnInst::Create(gIR->context(), asmb->abiret, bb);
            }
            else {
                llvm::ReturnInst::Create(gIR->context(), llvm::UndefValue::get(func->getReturnType()), bb);
            }
        }
        else
            llvm::ReturnInst::Create(gIR->context(), LLConstant::getNullValue(func->getReturnType()), bb);
    }

    // erase alloca point
    if (allocaPoint->getParent())
        allocaPoint->eraseFromParent();
    allocaPoint = 0;
    gIR->func()->allocapoint = 0;

    gIR->scopes.pop_back();

    // get rid of the endentry block, it's never used
    assert(!func->getBasicBlockList().empty());
    func->getBasicBlockList().pop_back();

    gIR->functions.pop_back();
}