verilator/src/V3LinkResolve.cpp
2014-06-08 21:36:18 -04:00

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// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Resolve module/signal name references
//
// Code available from: http://www.veripool.org/verilator
//
//*************************************************************************
//
// Copyright 2003-2014 by Wilson Snyder. This program is free software; you can
// redistribute it and/or modify it under the terms of either the GNU
// Lesser General Public License Version 3 or the Perl Artistic License
// Version 2.0.
//
// 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.
//
//*************************************************************************
// LinkResolve TRANSFORMATIONS:
// Top-down traversal
// Extracts:
// Add SUB so that we subtract off the "base 0-start" of the array
// SelBit: Convert to ArraySel
// Add SUB so that we subtract off the "base 0-start" of the array
// File operations
// Convert normal var to FILE* type
// SenItems: Convert pos/negedge of non-simple signals to temporaries
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include <cstdio>
#include <cstdarg>
#include <unistd.h>
#include <map>
#include <algorithm>
#include <vector>
#include "V3Global.h"
#include "V3LinkResolve.h"
#include "V3Ast.h"
//######################################################################
// Link state, as a visitor of each AstNode
class LinkResolveVisitor : public AstNVisitor {
private:
// NODE STATE
// Entire netlist:
// AstCaseItem::user2() // bool Moved default caseitems
AstUser2InUse m_inuser2;
// STATE
// Below state needs to be preserved between each module call.
AstNodeModule* m_modp; // Current module
AstNodeFTask* m_ftaskp; // Function or task we're inside
AstVAssert* m_assertp; // Current assertion
int m_senitemCvtNum; // Temporary signal counter
// METHODS
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
// VISITs
// TODO: Most of these visitors are here for historical reasons.
// TODO: ExpectDecriptor can move to data type resolution, and the rest
// TODO: could move to V3LinkParse to get them out of the way of elaboration
virtual void visit(AstNodeModule* nodep, AstNUser*) {
// Module: Create sim table for entire module and iterate
UINFO(8,"MODULE "<<nodep<<endl);
if (nodep->dead()) return;
m_modp = nodep;
m_senitemCvtNum = 0;
nodep->iterateChildren(*this);
m_modp = NULL;
}
virtual void visit(AstInitial* nodep, AstNUser*) {
nodep->iterateChildren(*this);
// Initial assignments under function/tasks can just be simple assignments without the initial
if (m_ftaskp) {
nodep->replaceWith(nodep->bodysp()->unlinkFrBackWithNext()); nodep=NULL;
}
}
virtual void visit(AstVAssert* nodep, AstNUser*) {
if (m_assertp) nodep->v3error("Assert not allowed under another assert");
m_assertp = nodep;
nodep->iterateChildren(*this);
m_assertp = NULL;
}
virtual void visit(AstVar* nodep, AstNUser*) {
nodep->iterateChildren(*this);
if (m_ftaskp) nodep->funcLocal(true);
if (nodep->isSigModPublic()) {
nodep->sigModPublic(false); // We're done with this attribute
m_modp->modPublic(true); // Avoid flattening if signals are exposed
}
}
virtual void visit(AstNodeVarRef* nodep, AstNUser*) {
// VarRef: Resolve its reference
if (nodep->varp()) {
nodep->varp()->usedParam(true);
}
nodep->iterateChildren(*this);
}
virtual void visit(AstNodeFTask* nodep, AstNUser*) {
// NodeTask: Remember its name for later resolution
// Remember the existing symbol table scope
m_ftaskp = nodep;
nodep->iterateChildren(*this);
m_ftaskp = NULL;
if (nodep->dpiExport()) {
nodep->scopeNamep(new AstScopeName(nodep->fileline()));
}
}
virtual void visit(AstNodeFTaskRef* nodep, AstNUser*) {
nodep->iterateChildren(*this);
if (nodep->taskp() && (nodep->taskp()->dpiContext() || nodep->taskp()->dpiExport())) {
nodep->scopeNamep(new AstScopeName(nodep->fileline()));
}
}
virtual void visit(AstSenItem* nodep, AstNUser*) {
// Remove bit selects, and bark if it's not a simple variable
nodep->iterateChildren(*this);
if (nodep->isClocked()) {
// If it's not a simple variable wrap in a temporary
// This is a bit unfortunate as we haven't done width resolution
// and any width errors will look a bit odd, but it works.
AstNode* sensp = nodep->sensp();
if (sensp
&& !sensp->castNodeVarRef()
&& !sensp->castConst()) {
// Make a new temp wire
string newvarname = "__Vsenitemexpr"+cvtToStr(++m_senitemCvtNum);
AstVar* newvarp = new AstVar (sensp->fileline(), AstVarType::MODULETEMP, newvarname,
VFlagLogicPacked(), 1);
// We can't just add under the module, because we may be inside a generate, begin, etc.
// We know a SenItem should be under a SenTree/Always etc, we we'll just hunt upwards
AstNode* addwherep = nodep; // Add to this element's next
while (addwherep->castSenItem()
|| addwherep->castSenTree()) {
addwherep = addwherep->backp();
}
if (!addwherep->castAlways()) { // Assertion perhaps?
sensp->v3error("Unsupported: Non-single-bit pos/negedge clock statement under some complicated block");
addwherep = m_modp;
}
addwherep->addNext(newvarp);
sensp->replaceWith(new AstVarRef (sensp->fileline(), newvarp, false));
AstAssignW* assignp = new AstAssignW
(sensp->fileline(),
new AstVarRef(sensp->fileline(), newvarp, true),
sensp);
addwherep->addNext(assignp);
}
} else { // Old V1995 sensitivity list; we'll probably mostly ignore
bool did=1;
while (did) {
did=0;
if (AstNodeSel* selp = nodep->sensp()->castNodeSel()) {
AstNode* fromp = selp->fromp()->unlinkFrBack();
selp->replaceWith(fromp); selp->deleteTree(); selp=NULL;
did=1;
}
// NodeSel doesn't include AstSel....
if (AstSel* selp = nodep->sensp()->castSel()) {
AstNode* fromp = selp->fromp()->unlinkFrBack();
selp->replaceWith(fromp); selp->deleteTree(); selp=NULL;
did=1;
}
if (AstNodePreSel* selp = nodep->sensp()->castNodePreSel()) {
AstNode* fromp = selp->lhsp()->unlinkFrBack();
selp->replaceWith(fromp); selp->deleteTree(); selp=NULL;
did=1;
}
}
}
if (!nodep->sensp()->castNodeVarRef()
&& !nodep->sensp()->castEnumItemRef()) { // V3Const will cleanup
if (debug()) nodep->dumpTree(cout,"-tree: ");
nodep->v3error("Unsupported: Complex statement in sensitivity list");
}
}
virtual void visit(AstSenGate* nodep, AstNUser*) {
nodep->v3fatalSrc("SenGates shouldn't be in tree yet");
}
virtual void visit(AstNodePreSel* nodep, AstNUser*) {
if (!nodep->attrp()) {
nodep->iterateChildren(*this);
// Constification may change the fromp() to a constant, which will lose the
// variable we're extracting from (to determine MSB/LSB/endianness/etc.)
// So we replicate it in another node
// Note that V3Param knows not to replace AstVarRef's under AstAttrOf's
AstNode* basefromp = AstArraySel::baseFromp(nodep);
if (AstNodeVarRef* varrefp = basefromp->castNodeVarRef()) { // Maybe varxref - so need to clone
nodep->attrp(new AstAttrOf(nodep->fileline(), AstAttrType::VAR_BASE,
varrefp->cloneTree(false)));
} else if (AstMemberSel* fromp = basefromp->castMemberSel()) {
nodep->attrp(new AstAttrOf(nodep->fileline(), AstAttrType::MEMBER_BASE,
fromp->cloneTree(false)));
} else {
nodep->v3fatalSrc("Illegal bit select; no signal/member being extracted from");
}
}
}
virtual void visit(AstCaseItem* nodep, AstNUser*) {
// Move default caseItems to the bottom of the list
// That saves us from having to search each case list twice, for non-defaults and defaults
nodep->iterateChildren(*this);
if (!nodep->user2() && nodep->isDefault() && nodep->nextp()) {
nodep->user2(true);
AstNode* nextp = nodep->nextp();
nodep->unlinkFrBack();
nextp->addNext(nodep);
}
}
virtual void visit(AstPragma* nodep, AstNUser*) {
if (nodep->pragType() == AstPragmaType::PUBLIC_MODULE) {
if (!m_modp) nodep->v3fatalSrc("PUBLIC_MODULE not under a module\n");
m_modp->modPublic(true);
nodep->unlinkFrBack(); pushDeletep(nodep); nodep=NULL;
}
else if (nodep->pragType() == AstPragmaType::PUBLIC_TASK) {
if (!m_ftaskp) nodep->v3fatalSrc("PUBLIC_TASK not under a task\n");
m_ftaskp->taskPublic(true);
m_modp->modPublic(true); // Need to get to the task...
nodep->unlinkFrBack(); pushDeletep(nodep); nodep=NULL;
}
else if (nodep->pragType() == AstPragmaType::COVERAGE_BLOCK_OFF) {
if (!v3Global.opt.coverageLine()) { // No need for block statements; may optimize better without
nodep->unlinkFrBack(); pushDeletep(nodep); nodep=NULL;
}
}
else {
nodep->iterateChildren(*this);
}
}
void expectFormat(AstNode* nodep, const string& format, AstNode* argp, bool isScan) {
// Check display arguments
bool inPct = false;
for (string::const_iterator it = format.begin(); it != format.end(); ++it) {
char ch = tolower(*it);
if (!inPct && ch=='%') {
inPct = true;
} else if (inPct) {
inPct = false;
switch (tolower(ch)) {
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
case '.':
inPct = true;
break;
case '%': break; // %% - just output a %
case 'm': // %m - auto insert "name"
if (isScan) nodep->v3error("Unsupported: %m in $fscanf");
break;
default: // Most operators, just move to next argument
if (!V3Number::displayedFmtLegal(ch)) {
nodep->v3error("Unknown $display-like format code: %"<<ch);
} else {
if (!argp) {
nodep->v3error("Missing arguments for $display-like format");
} else {
argp = argp->nextp();
}
}
break;
} // switch
}
}
if (argp) {
argp->v3error("Extra arguments for $display-like format");
}
}
void expectDescriptor(AstNode* nodep, AstNodeVarRef* filep) {
if (!filep) nodep->v3error("Unsupported: $fopen/$fclose/$f* descriptor must be a simple variable");
if (filep && filep->varp()) filep->varp()->attrFileDescr(true);
}
virtual void visit(AstFOpen* nodep, AstNUser*) {
nodep->iterateChildren(*this);
expectDescriptor(nodep, nodep->filep()->castNodeVarRef());
}
virtual void visit(AstFClose* nodep, AstNUser*) {
nodep->iterateChildren(*this);
expectDescriptor(nodep, nodep->filep()->castNodeVarRef());
}
virtual void visit(AstFEof* nodep, AstNUser*) {
nodep->iterateChildren(*this);
expectDescriptor(nodep, nodep->filep()->castNodeVarRef());
}
virtual void visit(AstFFlush* nodep, AstNUser*) {
nodep->iterateChildren(*this);
if (nodep->filep()) {
expectDescriptor(nodep, nodep->filep()->castNodeVarRef());
}
}
virtual void visit(AstFGetC* nodep, AstNUser*) {
nodep->iterateChildren(*this);
expectDescriptor(nodep, nodep->filep()->castNodeVarRef());
}
virtual void visit(AstFGetS* nodep, AstNUser*) {
nodep->iterateChildren(*this);
expectDescriptor(nodep, nodep->filep()->castNodeVarRef());
}
virtual void visit(AstFScanF* nodep, AstNUser*) {
nodep->iterateChildren(*this);
expectDescriptor(nodep, nodep->filep()->castNodeVarRef());
expectFormat(nodep, nodep->text(), nodep->exprsp(), true);
}
virtual void visit(AstSScanF* nodep, AstNUser*) {
nodep->iterateChildren(*this);
expectFormat(nodep, nodep->text(), nodep->exprsp(), true);
}
virtual void visit(AstSFormatF* nodep, AstNUser*) {
nodep->iterateChildren(*this);
expectFormat(nodep, nodep->text(), nodep->exprsp(), false);
if ((nodep->backp()->castDisplay() && nodep->backp()->castDisplay()->displayType().needScopeTracking())
|| nodep->formatScopeTracking()) {
nodep->scopeNamep(new AstScopeName(nodep->fileline()));
}
}
virtual void visit(AstDisplay* nodep, AstNUser* vup) {
nodep->iterateChildren(*this);
if (nodep->filep()) expectDescriptor(nodep, nodep->filep()->castNodeVarRef());
if (!m_assertp
&& (nodep->displayType() == AstDisplayType::DT_INFO
|| nodep->displayType() == AstDisplayType::DT_WARNING
|| nodep->displayType() == AstDisplayType::DT_ERROR
|| nodep->displayType() == AstDisplayType::DT_FATAL)) {
nodep->v3error(nodep->verilogKwd()+" only allowed under an assertion.");
}
}
virtual void visit(AstUdpTable* nodep, AstNUser*) {
UINFO(5,"UDPTABLE "<<nodep<<endl);
if (!v3Global.opt.bboxUnsup()) {
// We don't warn until V3Inst, so that UDPs that are in libraries and
// never used won't result in any warnings.
} else {
// Massive hack, just tie off all outputs so our analysis can proceed
AstVar* varoutp = NULL;
for (AstNode* stmtp = m_modp->stmtsp(); stmtp; stmtp=stmtp->nextp()) {
if (AstVar* varp = stmtp->castVar()) {
if (varp->isInput()) {
} else if (varp->isOutput()) {
if (varoutp) { varp->v3error("Multiple outputs not allowed in udp modules"); }
varoutp = varp;
// Tie off
m_modp->addStmtp(new AstAssignW(varp->fileline(),
new AstVarRef(varp->fileline(), varp, true),
new AstConst(varp->fileline(), AstConst::LogicFalse())));
} else {
varp->v3error("Only inputs and outputs are allowed in udp modules");
}
}
}
nodep->unlinkFrBack(); pushDeletep(nodep); nodep=NULL;
}
}
virtual void visit(AstScCtor* nodep, AstNUser*) {
// Constructor info means the module must remain public
m_modp->modPublic(true);
nodep->iterateChildren(*this);
}
virtual void visit(AstScDtor* nodep, AstNUser*) {
// Destructor info means the module must remain public
m_modp->modPublic(true);
nodep->iterateChildren(*this);
}
virtual void visit(AstScInt* nodep, AstNUser*) {
// Special class info means the module must remain public
m_modp->modPublic(true);
nodep->iterateChildren(*this);
}
virtual void visit(AstNode* nodep, AstNUser*) {
// Default: Just iterate
nodep->iterateChildren(*this);
}
public:
// CONSTUCTORS
LinkResolveVisitor(AstNetlist* rootp) {
m_ftaskp = NULL;
m_modp = NULL;
m_assertp = NULL;
m_senitemCvtNum = 0;
//
rootp->accept(*this);
}
virtual ~LinkResolveVisitor() {}
};
//######################################################################
// LinkBotupVisitor
// Recurses cells backwards, so we can pick up those things that propagate
// from child cells up to the top module.
class LinkBotupVisitor : public AstNVisitor {
private:
// STATE
AstNodeModule* m_modp; // Current module
// METHODS
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
// VISITs
virtual void visit(AstNetlist* nodep, AstNUser*) {
// Iterate modules backwards, in bottom-up order.
nodep->iterateChildrenBackwards(*this);
}
virtual void visit(AstNodeModule* nodep, AstNUser*) {
m_modp = nodep;
nodep->iterateChildren(*this);
m_modp = NULL;
}
virtual void visit(AstCell* nodep, AstNUser*) {
// Parent module inherits child's publicity
if (nodep->modp()->modPublic()) m_modp->modPublic(true);
//** No iteration for speed
}
virtual void visit(AstNodeMath* nodep, AstNUser*) {
// Speedup
}
virtual void visit(AstNode* nodep, AstNUser*) {
// Default: Just iterate
nodep->iterateChildren(*this);
}
public:
// CONSTUCTORS
LinkBotupVisitor(AstNetlist* rootp) {
m_modp = NULL;
//
rootp->accept(*this);
}
virtual ~LinkBotupVisitor() {}
};
//######################################################################
// Link class functions
void V3LinkResolve::linkResolve(AstNetlist* rootp) {
UINFO(4,__FUNCTION__<<": "<<endl);
LinkResolveVisitor visitor(rootp);
LinkBotupVisitor visitorb(rootp);
}