C++ AstNode::castVarRef方法代码示例

    // VISITORS
    virtual void visit(AstNodeVarRef* nodep, AstNUser*) {
	if (nodep->varScopep() == m_elimVarScp) {
	    // Substitute in the new tree
	    // It's possible we substitute into something that will be reduced more later
	    // however, as we never delete the top Always/initial statement, all should be well.
	    m_didReplace = true;
	    if (nodep->lvalue()) nodep->v3fatalSrc("Can't replace lvalue assignments with const var");
	    AstNode* substp = m_replaceTreep->cloneTree(false);
	    if (nodep->castNodeVarRef()
		&& substp->castNodeVarRef()
		&& nodep->same(substp)) {
		// Prevent a infinite loop...
		substp->v3fatalSrc("Replacing node with itself; perhaps circular logic?");
	    }
	    // Which fileline() to use?
	    // If replacing with logic, an error/warning is likely to want to point to the logic
	    // IE what we're replacing with.
	    // However a VARREF should point to the original as it's otherwise confusing
	    // to throw warnings that point to a PIN rather than where the pin us used.
	    if (substp->castVarRef()) substp->fileline(nodep->fileline());
	    // Make the substp an rvalue like nodep. This facilitate the hashing in dedupe.
	    if (AstNodeVarRef* varrefp = substp->castNodeVarRef()) varrefp->lvalue(false);
	    nodep->replaceWith(substp);
	    nodep->deleteTree(); VL_DANGLING(nodep);
	}
    }

    virtual void visit(AstPin* nodep, AstNUser*) {
	// Any non-direct pins need reconnection with a part-select
	if (!nodep->exprp()) return; // No-connect
	if (m_cellRangep) {
	    UINFO(4,"   PIN  "<<nodep<<endl);
	    int pinwidth = nodep->modVarp()->width();
	    int expwidth = nodep->exprp()->width();
	    if (expwidth == pinwidth) {
		// NOP: Arrayed instants: widths match so connect to each instance
	    } else if (expwidth == pinwidth*m_cellRangep->elementsConst()) {
		// Arrayed instants: one bit for each of the instants (each assign is 1 pinwidth wide)
		AstNode* exprp = nodep->exprp()->unlinkFrBack();
		bool inputPin = nodep->modVarp()->isInput();
		if (!inputPin && !exprp->castVarRef()
		    && !exprp->castConcat()  // V3Const will collapse the SEL with the one we're about to make
		    && !exprp->castSel()) {  // V3Const will collapse the SEL with the one we're about to make
		    nodep->v3error("Unsupported: Per-bit array instantiations with output connections to non-wires.");
		    // Note spec allows more complicated matches such as slices and such
		}
		exprp = new AstSel (exprp->fileline(), exprp,
				    pinwidth*(m_instNum-m_instLsb),
				    pinwidth);
		nodep->exprp(exprp);
	    } else {
		nodep->v3fatalSrc("Width mismatch; V3Width should have errored out.");
	    }
	}
    }

    //*******************************************************************
    // The following visitor functions deal with detecting Z's in the
    // logic, stripping the Z's out and creating an __en signal and its
    // logic.
    //*******************************************************************
    virtual void visit(AstPull* nodep, AstNUser*) {
        // replace any pullup/pulldowns with assignw logic and an __en
        // signal just like it is any other tristate signal.  The only
        // difference is that the user2() variable on the __en signal
        // will be given a pull direction--i.e. pulldown=1, pullup=2.
        // This will signal the driver exansion logic to put a default
        // pullup or pulldown state on the tristate bus under the high-Z
        // condition when no one is driving the bus.  Given the complexity
        // of merging tristate drivers at any level, the current limitation
        // of this implementation is that a pullup/down gets applied
        // to all bits of a bus and a bus cannot have drivers in opposite
        // directions on indvidual pins.
        AstNode* outp = nodep->lhsp()->unlinkFrBack();;
        AstVarRef* outrefp = NULL;
	int width=-1;
	if (outp->castVarRef()) {
	    outrefp = outp->castVarRef();
	} else if (outp->castSel()) {
	    outrefp = outp->castSel()->fromp()->castVarRef();
	    width = outp->castSel()->widthConst();
	} else {
	    nodep->v3error("Can't find LHS varref");
	}
	outrefp->lvalue(true);
	AstVar* varp = outrefp->varp();
	if (width==-1) width=varp->width();

        V3Number num0 (nodep->fileline(), width);
	num0.setAllBits0();
	V3Number num1 (nodep->fileline(), width);
	num1.setAllBits1();

	AstConst* enrhsp = new AstConst(nodep->fileline(), num0);
	AstVar* enp = createEnableVar(outp, outrefp, enrhsp, width, "pull");
	enp->user2(nodep->direction()+1); // record the pull direction

	AstAssignW* newassp = new AstAssignW(nodep->fileline(), outp,
					     new AstConst(nodep->fileline(), nodep->direction() ? num1 : num0));
	nodep->replaceWith(newassp);
	nodep->deleteTree(); nodep=NULL;
	newassp->iterateChildren(*this);
    }

    unsigned explicitDimensions(AstArraySel* nodep) {
	// Find out how many explicit dimensions are in a given ArraySel.
	unsigned dim = 0;
	AstNode* fromp = nodep;
	AstArraySel* selp;
	do {
	    selp = fromp->castArraySel();
	    if (!selp) {
		nodep->user1p(fromp->castVarRef());
		selp = NULL;
		break;
	    } else {
		fromp = selp->fromp();
		if (fromp) ++dim;
	    }
	} while (fromp && selp);
	if (!nodep->user1p()) nodep->v3fatalSrc("Couldn't find VarRef under the ArraySel");
	return dim;
    }

    virtual void visit(AstCell* nodep, AstNUser*) {
	if (nodep->modp()->user1()) {  // Marked with inline request
	    UINFO(5," Inline CELL   "<<nodep<<endl);
	    UINFO(5,"   To MOD      "<<m_modp<<endl);
	    ++m_statCells;

	    // Before cloning simplify pin assignments
	    // Better off before, as if module has multiple instantiations
	    // we'll save work, and we can't call pinReconnectSimple in
	    // this loop as it clone()s itself.
	    for (AstPin* pinp = nodep->pinsp(); pinp; pinp=pinp->nextp()->castPin()) {
		if (!pinp->exprp()) continue;
		V3Inst::pinReconnectSimple(pinp, nodep, m_modp, false);
	    }

	    // Clone original module
	    if (debug()>=9) { nodep->dumpTree(cout,"inlcell:"); }
	    //if (debug()>=9) { nodep->modp()->dumpTree(cout,"oldmod:"); }
	    AstNodeModule* newmodp = nodep->modp()->cloneTree(false);
	    if (debug()>=9) { newmodp->dumpTree(cout,"newmod:"); }
	    // Clear var markings and find cell cross references
	    AstNode::user2ClearTree();
	    AstNode::user4ClearTree();
	    { InlineCollectVisitor(nodep->modp()); }  // {} to destroy visitor immediately
	    // Create data for dotted variable resolution
	    AstCellInline* inlinep = new AstCellInline(nodep->fileline(),
						       nodep->name(), nodep->modp()->origName());
	    m_modp->addInlinesp(inlinep);  // Must be parsed before any AstCells
	    // Create assignments to the pins
	    for (AstPin* pinp = nodep->pinsp(); pinp; pinp=pinp->nextp()->castPin()) {
		if (!pinp->exprp()) continue;
		UINFO(6,"     Pin change from "<<pinp->modVarp()<<endl);
		// Make new signal; even though we'll optimize the interconnect, we
		// need an alias to trace correctly.  If tracing is disabled, we'll
		// delete it in later optimizations.
		AstVar* pinOldVarp = pinp->modVarp();
		AstVar* pinNewVarp = pinOldVarp->clonep()->castVar();

		AstNode* connectRefp = pinp->exprp();
		if (!connectRefp->castConst() && !connectRefp->castVarRef()) {
		    pinp->v3fatalSrc("Unknown interconnect type; pinReconnectSimple should have cleared up\n");
		}
		if (pinNewVarp->isOutOnly() && connectRefp->castConst()) {
		    pinp->v3error("Output port is connected to a constant pin, electrical short");
		}

		// Propagate any attributes across the interconnect
		pinNewVarp->propagateAttrFrom(pinOldVarp);
		if (connectRefp->castVarRef()) {
		    connectRefp->castVarRef()->varp()->propagateAttrFrom(pinOldVarp);
		}

		// One to one interconnect won't make a temporary variable.
		// This prevents creating a lot of extra wires for clock signals.
		// It will become a tracing alias.
		UINFO(6,"One-to-one "<<connectRefp<<endl);
		UINFO(6,"       -to "<<pinNewVarp<<endl);
		pinNewVarp->user2p(connectRefp);
		// Public output inside the cell must go via an assign rather than alias
		// Else the public logic will set the alias, loosing the value to be propagated up
		// (InOnly isn't a problem as the AssignAlias will create the assignment for us)
		pinNewVarp->user3(pinNewVarp->isSigUserRWPublic() && pinNewVarp->isOutOnly());
	    }
	    // Cleanup var names, etc, to not conflict
	    { InlineRelinkVisitor(newmodp, m_modp, nodep); }
	    // Move statements to top module
	    if (debug()>=9) { newmodp->dumpTree(cout,"fixmod:"); }
	    AstNode* stmtsp = newmodp->stmtsp();
	    if (stmtsp) stmtsp->unlinkFrBackWithNext();
	    if (stmtsp) m_modp->addStmtp(stmtsp);
	    // Remove the cell
	    newmodp->deleteTree(); newmodp=NULL; // Clear any leftover ports, etc
	    nodep->unlinkFrBack();
	    pushDeletep(nodep); nodep = NULL;
	    if (debug()>=9) { m_modp->dumpTree(cout,"donemod:"); }
	}
    }

void ParamVisitor::visitCell(AstCell* nodep) {
    // Cell: Check for parameters in the instantiation.
    nodep->iterateChildren(*this);
    if (!nodep->modp()) nodep->v3fatalSrc("Not linked?");
    if (nodep->paramsp()
	|| 1  // Need to look for interfaces; could track when one exists, but should be harmless to always do this
	) {
	UINFO(4,"De-parameterize: "<<nodep<<endl);
	// Create new module name with _'s between the constants
	if (debug()>=10) nodep->dumpTree(cout,"-cell:\t");
	// Evaluate all module constants
	V3Const::constifyParamsEdit(nodep);

	// Make sure constification worked
	// Must be a separate loop, as constant conversion may have changed some pointers.
	//if (debug()) nodep->dumpTree(cout,"-cel2:\t");
	string longname = nodep->modp()->name();
	bool any_overrides = false;
	longname += "_";
	if (debug()>8) nodep->paramsp()->dumpTreeAndNext(cout,"-cellparams:\t");
	for (AstPin* pinp = nodep->paramsp(); pinp; pinp=pinp->nextp()->castPin()) {
	    if (!pinp->exprp()) continue; // No-connect
	    AstVar* modvarp = pinp->modVarp();
	    if (!modvarp) {
		pinp->v3error("Parameter not found in sub-module: Param "<<pinp->name()<<" of "<<nodep->prettyName());
	    } else if (!modvarp->isGParam()) {
		pinp->v3error("Attempted parameter setting of non-parameter: Param "<<pinp->name()<<" of "<<nodep->prettyName());
	    } else {
		AstConst* constp = pinp->exprp()->castConst();
		AstConst* origconstp = modvarp->valuep()->castConst();
		if (!constp) {
		    //if (debug()) pinp->dumpTree(cout,"error:");
		    pinp->v3error("Can't convert defparam value to constant: Param "<<pinp->name()<<" of "<<nodep->prettyName());
		    pinp->exprp()->replaceWith(new AstConst(pinp->fileline(), V3Number(pinp->fileline(), modvarp->width(), 0)));
		} else if (origconstp && constp->sameTree(origconstp)) {
		    // Setting parameter to its default value.  Just ignore it.
		    // This prevents making additional modules, and makes coverage more
		    // obvious as it won't show up under a unique module page name.
		} else {
		    longname += "_" + paramSmallName(nodep->modp(),pinp->modVarp())+constp->num().ascii(false);
		    any_overrides = true;
		}
	    }
	}
	IfaceRefRefs ifaceRefRefs;
	for (AstPin* pinp = nodep->pinsp(); pinp; pinp=pinp->nextp()->castPin()) {
	    AstVar* modvarp = pinp->modVarp();
	    if (modvarp->isIfaceRef()) {
		AstIfaceRefDType* portIrefp = modvarp->subDTypep()->castIfaceRefDType();
		AstIfaceRefDType* pinIrefp = NULL;
		AstNode *exprp = pinp->exprp();
		if (exprp
		    && exprp->castVarRef()
		    && exprp->castVarRef()->varp()
		    && exprp->castVarRef()->varp()->subDTypep()
		    && exprp->castVarRef()->varp()->subDTypep()->castIfaceRefDType())
		    pinIrefp = exprp->castVarRef()->varp()->subDTypep()->castIfaceRefDType();
		else if (exprp
			 && exprp->op1p()
			 && exprp->op1p()->castVarRef()
			 && exprp->op1p()->castVarRef()->varp()
			 && exprp->op1p()->castVarRef()->varp()->subDTypep()
			 && exprp->op1p()->castVarRef()->varp()->subDTypep()->castUnpackArrayDType()
			 && exprp->op1p()->castVarRef()->varp()->subDTypep()->castUnpackArrayDType()->subDTypep()
			 && exprp->op1p()->castVarRef()->varp()->subDTypep()->castUnpackArrayDType()->subDTypep()->castIfaceRefDType())
		    pinIrefp = exprp->op1p()->castVarRef()->varp()->subDTypep()->castUnpackArrayDType()->subDTypep()->castIfaceRefDType();
		//UINFO(9,"     portIfaceRef "<<portIrefp<<endl);

		if (!pinIrefp) {
		    pinp->v3error("Interface port '"<<modvarp->prettyName()<<"' is not connected to interface/modport pin expression");
		} else {
		    //UINFO(9,"     pinIfaceRef "<<pinIrefp<<endl);
		    if (portIrefp->ifaceViaCellp() != pinIrefp->ifaceViaCellp()) {
			UINFO(9,"     IfaceRefDType needs reconnect  "<<pinIrefp<<endl);
			longname += "_" + paramSmallName(nodep->modp(),pinp->modVarp())+paramValueNumber(pinIrefp);
			any_overrides = true;
			ifaceRefRefs.push_back(make_pair(portIrefp,pinIrefp));
		    }
		}
	    }
	}

	if (!any_overrides) {
	    UINFO(8,"Cell parameters all match original values, skipping expansion.\n");
	} else {
	    // If the name is very long, we don't want to overwhelm the filename limit
	    // We don't do this always, as it aids debugability to have intuitive naming.
	    // TODO can use new V3Name hash replacement instead of this
	    string newname = longname;
	    if (longname.length()>30) {
		LongMap::iterator iter = m_longMap.find(longname);
		if (iter != m_longMap.end()) {
		    newname = iter->second;
		} else {
		    newname = nodep->modp()->name();
		    newname += "__pi"+cvtToStr(++m_longId);  // We use all upper case above, so lower here can't conflict
		    m_longMap.insert(make_pair(longname, newname));
		}
	    }
	    UINFO(4,"Name: "<<nodep->modp()->name()<<"->"<<longname<<"->"<<newname<<endl);
//.........这里部分代码省略.........