verilator/src/V3Link.cpp
2008-06-30 13:11:25 -04:00

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//*************************************************************************
// DESCRIPTION: Verilator: Resolve module/signal name references
//
// Code available from: http://www.veripool.org/verilator
//
// AUTHORS: Wilson Snyder with Paul Wasson, Duane Gabli
//
//*************************************************************************
//
// Copyright 2003-2008 by Wilson Snyder. This program is free software; you can
// redistribute it and/or modify it under the terms of either the GNU
// General Public License or the Perl Artistic License.
//
// Verilator is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
//*************************************************************************
// Link TRANSFORMATIONS:
// Top-down traversal
// Cells:
// Connect pins
// VarRef's:
// Link to var they reference
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include <cstdio>
#include <cstdarg>
#include <unistd.h>
#include <map>
#include <algorithm>
#include <vector>
#include "V3Global.h"
#include "V3Link.h"
#include "V3SymTable.h"
#include "V3Ast.h"
//######################################################################
// Link state, as a visitor of each AstNode
class LinkVisitor : public AstNVisitor {
private:
// NODE STATE
// Entire netlist:
// AstModule::userp() // V3SymTable* Module's Symbol table
// AstNodeFTask::userp() // V3SymTable* Local Symbol table
// AstBegin::userp() // V3SymTable* Local Symbol table
// AstVar::userp() // V3SymTable* Table used to create this variable
// ENUMS
enum IdState { // Which loop through the tree
ID_FIND, // Find all identifiers and add to lists
ID_PARAM, // Move parameters to cell definitions
ID_RESOLVE}; // Resolve all identifiers and report errors
// STATE
// Below state needs to be preserved between each module call.
AstModule* m_modp; // Current module
IdState m_idState; // Id linking mode (find or resolve)
int m_paramNum; // Parameter number, for position based connection
V3SymTable* m_curVarsp; // Symbol table of variables and tasks under table we're inserting into
V3SymTable* m_cellVarsp; // Symbol table of variables under cell's module
int m_beginNum; // Begin block number, 0=none seen
vector<V3SymTable*> m_delSymps; // Symbol tables to delete
//int debug() { return 9; }
// METHODS
void linkVarName (AstVarRef* nodep) {
if (!nodep->varp()) {
AstVar* varp = m_curVarsp->findIdName(nodep->name())->castVar();
nodep->varp(varp);
}
}
const char* varTextType(AstNode* nodep) {
const char* what = "node";
if (nodep->castVar()) what = "variable";
else if (nodep->castCell()) what = "cell";
else if (nodep->castTask()) what = "task";
else if (nodep->castFunc()) what = "function";
return what;
}
void createImplicitVar (AstVarRef* forrefp, bool noWarn) {
// Create implicit after warning
linkVarName(forrefp);
if (!forrefp->varp()) {
if (!noWarn) forrefp->v3warn(IMPLICIT,"Signal definition not found, creating implicitly: "<<forrefp->prettyName());
AstVar* newp = new AstVar (forrefp->fileline(), AstVarType::WIRE,
forrefp->name());
newp->trace(m_modp->modTrace());
m_modp->addStmtp(newp);
// Link it to signal list
IdState old_id = m_idState;
m_idState = ID_FIND;
newp->accept(*this);
m_idState = old_id;
}
}
// VISITs
virtual void visit(AstNetlist* nodep, AstNUser*) {
AstNode::userClearTree();
// Look at all modules, and store pointers to all module names
for (AstModule* modp = v3Global.rootp()->modulesp(); modp; modp=modp->nextp()->castModule()) {
V3SymTable* symp = new V3SymTable(NULL);
m_delSymps.push_back(symp);
modp->userp(symp);
}
// And recurse...
m_idState = ID_FIND;
nodep->iterateChildren(*this);
m_idState = ID_PARAM;
nodep->iterateChildren(*this);
m_idState = ID_RESOLVE;
nodep->iterateChildren(*this);
nodep->checkTree();
}
virtual void visit(AstModule* nodep, AstNUser*) {
// Module: Create sim table for entire module and iterate
UINFO(2,"Link Module: "<<nodep<<endl);
m_modp = nodep;
// This state must be save/restored in the cell visitor function
m_curVarsp = nodep->userp()->castSymTable();
if (!m_curVarsp) nodep->v3fatalSrc("NULL");
m_cellVarsp = NULL;
m_paramNum = 0;
m_beginNum = 0;
nodep->iterateChildren(*this);
// Prep for next
m_curVarsp = NULL;
m_modp = NULL;
}
virtual void visit(AstVar* nodep, AstNUser*) {
// Var: Remember its name for later resolution
if (!m_curVarsp) nodep->v3fatalSrc("Var not under module??\n");
nodep->iterateChildren(*this);
if (m_idState==ID_FIND) {
// We used modTrace before leveling, and we may now
// want to turn it off now that we know the levelizations
if (v3Global.opt.traceDepth()
&& (m_modp->level()-1) > v3Global.opt.traceDepth()) {
m_modp->modTrace(false);
nodep->trace(false);
}
// Find under either a task or the module's vars
AstNode* findidp = m_curVarsp->findIdName(nodep->name());
AstVar* findvarp = findidp->castVar();
bool ins=false;
if (!findidp) {
ins=true;
} else if (!findvarp) {
nodep->v3error("Unsupported in C: Variable has same name as "
<<varTextType(findidp)<<": "<<nodep->prettyName());
} else if (findvarp != nodep) {
UINFO(4,"DupVar: "<<nodep<<" ;; "<<findvarp<<endl);
if (findvarp->userp() == m_curVarsp) { // Only when on same level
if ((findvarp->isIO() && nodep->isSignal())
|| (findvarp->isSignal() && nodep->isIO())) {
findvarp->combineType(nodep);
nodep->unlinkFrBack()->deleteTree(); nodep=NULL;
} else {
nodep->v3error("Duplicate declaration of signal: "<<nodep->prettyName());
findvarp->v3error("... Location of original declaration");
}
} else {
// User can disable the message at either point
if (!nodep->fileline()->warnIsOff(V3ErrorCode::VARHIDDEN)
&& !findvarp->fileline()->warnIsOff(V3ErrorCode::VARHIDDEN)) {
nodep->v3warn(VARHIDDEN,"Declaration of signal hides declaration in upper scope: "<<nodep->name());
findvarp->v3warn(VARHIDDEN,"... Location of original declaration");
}
ins = true;
}
}
if (ins) {
m_curVarsp->insert(nodep->name(), nodep);
nodep->userp(m_curVarsp);
if (nodep->isGParam()) {
m_paramNum++;
m_curVarsp->insert("__paramNumber"+cvtToStr(m_paramNum), nodep);
}
}
}
}
virtual void visit(AstVarRef* nodep, AstNUser*) {
// VarRef: Resolve its reference
if (m_idState==ID_RESOLVE && !nodep->varp()) {
linkVarName(nodep);
if (!nodep->varp()) {
nodep->v3error("Can't find definition of signal: "<<nodep->prettyName());
createImplicitVar (nodep, true); // So only complain once
}
}
nodep->iterateChildren(*this);
}
//virtual void visit(AstVarXRef* nodep, AstNUser*) {
// See LinkDotVisitor
//}
virtual void visit(AstNodeFTask* nodep, AstNUser*) {
// NodeTask: Remember its name for later resolution
if (!m_curVarsp) nodep->v3fatalSrc("Function/Task not under module??\n");
// Remember the existing symbol table scope
V3SymTable* upperVarsp = m_curVarsp;
{
// Create symbol table for the task's vars
if (V3SymTable* localVarsp = nodep->userp()->castSymTable()) {
m_curVarsp = localVarsp;
} else {
m_curVarsp = new V3SymTable(upperVarsp);
m_delSymps.push_back(m_curVarsp);
nodep->userp(m_curVarsp);
}
// Convert the func's range to the output variable
// This should probably be done in the Parser instead, as then we could
// just attact normal signal attributes to it.
if (AstFunc* funcp = nodep->castFunc()) {
if (!funcp->fvarp()->castVar()) {
AstRange* rangep = funcp->fvarp()->castRange();
if (rangep) rangep->unlinkFrBack();
AstVar* newvarp = new AstVar(nodep->fileline(), AstVarType::OUTPUT, nodep->name(), rangep);
newvarp->isSigned(funcp->isSigned());
newvarp->funcReturn(true);
newvarp->trace(false); // Not user visible
newvarp->attrIsolateAssign(funcp->attrIsolateAssign());
funcp->addFvarp(newvarp);
// Explicit insert required, as the var name shadows the upper level's task name
m_curVarsp->insert(newvarp->name(), newvarp);
}
}
nodep->iterateChildren(*this);
}
m_curVarsp = upperVarsp;
if (m_idState==ID_FIND) {
AstNode* findidp = m_curVarsp->findIdName(nodep->name());
AstNodeFTask* findtaskp = findidp->castNodeFTask();
if (!findidp) {
m_curVarsp->insert(nodep->name(), nodep);
} else if (!findtaskp) {
nodep->v3error("Unsupported in C: Task/function has same name as "
<<varTextType(findidp)<<": "<<nodep->prettyName());
} else if (findtaskp!=nodep) {
nodep->v3error("Duplicate declaration of task/function: "<<nodep->prettyName());
}
}
}
virtual void visit(AstBegin* nodep, AstNUser*) {
// Link variables underneath blocks
// Remember the existing symbol table scope
V3SymTable* upperVarsp = m_curVarsp;
// Rename "genblk"s to include a number
// All blocks are numbered in the standard, IE we start with "genblk1" even if only one.
UINFO(8," "<<nodep<<endl);
if (m_idState==ID_FIND && nodep->name() == "genblk") {
++m_beginNum;
nodep->name(nodep->name()+cvtToStr(m_beginNum));
}
// Recurse
int oldNum = m_beginNum;
m_beginNum = 0;
{
// Create symbol table for the task's vars
if (V3SymTable* localVarsp = nodep->userp()->castSymTable()) {
m_curVarsp = localVarsp;
} else {
m_curVarsp = new V3SymTable(upperVarsp);
m_delSymps.push_back(m_curVarsp);
nodep->userp(m_curVarsp);
}
nodep->iterateChildren(*this);
}
m_curVarsp = upperVarsp;
m_beginNum = oldNum;
}
virtual void visit(AstNodeFTaskRef* nodep, AstNUser*) {
// NodeFTaskRef: Resolve its reference
if (m_idState==ID_RESOLVE && !nodep->taskp()) {
if (nodep->dotted() == "") {
AstNodeFTask* taskp = m_curVarsp->findIdName(nodep->name())->castNodeFTask();
if (!taskp) { nodep->v3error("Can't find definition of task/function: "<<nodep->prettyName()); }
nodep->taskp(taskp);
}
}
nodep->iterateChildren(*this);
}
virtual void visit(AstCell* nodep, AstNUser*) {
// Cell: Resolve its filename. If necessary, parse it.
if (m_idState==ID_FIND) {
// Add to list of all cells, for error checking and defparam's
AstNode* findidp = m_curVarsp->findIdName(nodep->name());
AstCell* findcellp = findidp->castCell();
if (!findidp) {
m_curVarsp->insert(nodep->name(), nodep);
} else if (!findcellp) {
nodep->v3error("Unsupported in C: Cell has same name as "
<<varTextType(findidp)<<": "<<nodep->prettyName());
} else if (findcellp != nodep) {
nodep->v3error("Duplicate name of cell: "<<nodep->prettyName());
}
}
if (!nodep->modp()) {
nodep->v3fatalSrc("Cell has unlinked module"); // V3LinkCell should have errored out
}
else {
// Need to pass the module info to this cell, so we can link up the pin names
m_cellVarsp = nodep->modp()->userp()->castSymTable();
UINFO(4,"(Backto) Link Cell: "<<nodep<<endl);
//if (debug()) { nodep->dumpTree(cout,"linkcell:"); }
//if (debug()) { nodep->modp()->dumpTree(cout,"linkcemd:"); }
nodep->iterateChildren(*this);
m_cellVarsp = NULL;
}
// Parent module inherits child's publicity
// This is done bottom up in the LinkBotupVisitor stage
}
virtual void visit(AstPort* nodep, AstNUser*) {
// Port: Stash the pin number
if (!m_curVarsp) nodep->v3fatalSrc("Port not under module??\n");
if (m_idState==ID_PARAM) {
// Need to set pin numbers after varnames are created
// But before we do the final resolution based on names
AstVar* refp = m_curVarsp->findIdName(nodep->name())->castVar();
if (!refp) {
nodep->v3error("Input/output/inout declaration not found for port: "<<nodep->prettyName());
} else if (!refp->isIO()) {
nodep->v3error("Pin is not a in/out/inout: "<<nodep->prettyName());
} else {
m_curVarsp->insert("__pinNumber"+cvtToStr(nodep->pinNum()), refp);
}
// Ports not needed any more
nodep->unlinkFrBack()->deleteTree(); nodep=NULL;
}
}
void pinImplicitExprRecurse(AstNode* nodep) {
// Under a pin, Check interconnect expression for a pin reference or a concat.
// Create implicit variable as needed
if (AstVarRef* varrefp = nodep->castVarRef()) {
// To prevent user errors, we should only do single bit
// implicit vars, however some netlists (MIPS) expect single
// bit implicit wires to get created with range 0:0 etc.
//if (!nodep->modVarp()->rangep()) ...
createImplicitVar(varrefp, false);
}
else if (AstConcat* concp = nodep->castConcat()) {
pinImplicitExprRecurse(concp->lhsp());
pinImplicitExprRecurse(concp->rhsp());
}
}
virtual void visit(AstPin* nodep, AstNUser*) {
// Pin: Link to submodule's pin
if (!m_cellVarsp) nodep->v3fatalSrc("Pin not under cell?\n");
if (m_idState==ID_RESOLVE && !nodep->modVarp()) {
AstVar* refp = m_cellVarsp->findIdName(nodep->name())->castVar();
if (!refp) {
nodep->v3error("Pin not found: "<<nodep->prettyName());
} else if (!refp->isIO() && !refp->isParam()) {
nodep->v3error("Pin is not a in/out/inout/param: "<<nodep->prettyName());
} else {
nodep->modVarp(refp);
}
}
// Deal with implicit definitions
if (m_idState==ID_RESOLVE && nodep->modVarp()
&& !nodep->svImplicit()) { // SV 19.11.3: .name pins don't allow implicit decls
pinImplicitExprRecurse(nodep->exprp());
}
nodep->iterateChildren(*this);
}
virtual void visit(AstAssignW* nodep, AstNUser*) {
// Deal with implicit definitions
// We used to nodep->allowImplicit() here, but it turns out
// normal "assigns" can also make implicit wires. Yuk.
if (AstVarRef* forrefp = nodep->lhsp()->castVarRef()) {
createImplicitVar(forrefp, false);
}
nodep->iterateChildren(*this);
}
virtual void visit(AstDefParam* nodep, AstNUser*) {
nodep->iterateChildren(*this);
if (m_idState==ID_PARAM) {
AstNode* findidp = m_curVarsp->findIdName(nodep->path());
AstCell* cellp = findidp->castCell();
if (!cellp) {
nodep->v3error("In defparam, cell "<<nodep->path()<<" never declared");
} else {
AstNode* exprp = nodep->rhsp()->unlinkFrBack();
UINFO(9,"Defparam cell "<<nodep->path()<<"."<<nodep->name()
<<" <= "<<exprp<<endl);
// Don't need to check the name of the defparam exists. V3Param does.
AstPin* pinp = new AstPin (nodep->fileline(),
-1, // Pin# not relevant
nodep->name(),
exprp);
cellp->addParamsp(pinp);
nodep->unlinkFrBack()->deleteTree(); nodep=NULL;
}
}
}
virtual void visit(AstNode* nodep, AstNUser*) {
// Default: Just iterate
nodep->iterateChildren(*this);
}
public:
// CONSTUCTORS
LinkVisitor(AstNetlist* rootp) {
m_curVarsp = NULL;
m_cellVarsp = NULL;
m_modp = NULL;
m_paramNum = 0;
m_beginNum = 0;
//
rootp->accept(*this);
}
virtual ~LinkVisitor() {
for (vector<V3SymTable*>::iterator it = m_delSymps.begin(); it != m_delSymps.end(); ++it) {
delete (*it);
}
}
};
//######################################################################
// Link class functions
void V3Link::link(AstNetlist* rootp) {
UINFO(4,__FUNCTION__<<": "<<endl);
LinkVisitor visitor(rootp);
}