verilator/src/V3Coverage.cpp

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// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Netlist (top level) functions
//
// Code available from: http://www.veripool.org/verilator
//
//*************************************************************************
//
// Copyright 2003-2018 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.
//
//*************************************************************************
// COVERAGE TRANSFORMATIONS:
// At each IF/(IF else)/CASEITEM,
// If there's no coverage off on the block below it,
// or a $stop
// Insert a COVERDECL node in the module.
// (V3Emit reencodes into per-module numbers for emitting.)
// Insert a COVERINC node at the end of the statement list
// for that if/else/case.
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include "V3Global.h"
#include "V3Coverage.h"
#include "V3Ast.h"
#include <cstdarg>
#include <map>
//######################################################################
// Coverage state, as a visitor of each AstNode
class CoverageVisitor : public AstNVisitor {
private:
// TYPES
typedef std::map<string,int> FileMap;
struct ToggleEnt {
string m_comment; // Comment for coverage dump
AstNode* m_varRefp; // How to get to this element
AstNode* m_chgRefp; // How to get to this element
ToggleEnt(const string& comment, AstNode* vp, AstNode* cp)
: m_comment(comment), m_varRefp(vp), m_chgRefp(cp) {}
~ToggleEnt() {}
void cleanup() {
m_varRefp->deleteTree(); m_varRefp=NULL;
m_chgRefp->deleteTree(); m_chgRefp=NULL;
}
};
// NODE STATE
// Entire netlist:
// AstIf::user1() -> bool. True indicates ifelse processed
AstUser1InUse m_inuser1;
// STATE
bool m_checkBlock; // Should this block get covered?
AstNodeModule* m_modp; // Current module to add statement to
bool m_inToggleOff; // In function/task etc
bool m_inModOff; // In module with no coverage
FileMap m_fileps; // Column counts for each fileline
string m_beginHier; // AstBegin hier name for user coverage points
// METHODS
VL_DEBUG_FUNC; // Declare debug()
const char* varIgnoreToggle(AstVar* nodep) {
// Return true if this shouldn't be traced
// See also similar rule in V3TraceDecl::varIgnoreTrace
if (!nodep->isToggleCoverable())
return "Not relevant signal type";
if (!v3Global.opt.coverageUnderscore()) {
string prettyName = nodep->prettyName();
if (prettyName[0] == '_')
return "Leading underscore";
if (prettyName.find("._") != string::npos)
return "Inlined leading underscore";
}
if ((nodep->width()*nodep->dtypep()->arrayUnpackedElements()) > 256) return "Wide bus/array > 256 bits";
// We allow this, though tracing doesn't
// if (nodep->arrayp(1)) return "Unsupported: Multi-dimensional array";
return NULL;
}
AstCoverInc* newCoverInc(FileLine* fl, const string& hier,
const string& page_prefix, const string& comment) {
// For line coverage, we may have multiple if's on one line, so disambiguate if
// everything is otherwise identical
// (Don't set column otherwise as it may result in making bins not match up with
// different types of coverage enabled.)
string key = fl->filename()+"\001"+cvtToStr(fl->lineno())+"\001"+hier+"\001"+page_prefix+"\001"+comment;
int column = 0;
FileMap::iterator it = m_fileps.find(key);
if (it == m_fileps.end()) {
m_fileps.insert(make_pair(key,column+1));
} else {
column = (it->second)++;
}
// We could use the basename of the filename to the page, but seems better for code
// from an include file to be listed under the module using it rather than the include file.
// Note the module name could have parameters appended, we'll consider this
// a feature as it allows for each parameterized block to be counted separately.
// Someday the user might be allowed to specify a different page suffix
string page = page_prefix + "/" + m_modp->prettyName();
AstCoverDecl* declp = new AstCoverDecl(fl, column, page, comment);
declp->hier(hier);
m_modp->addStmtp(declp);
return new AstCoverInc(fl, declp);
}
// VISITORS - BOTH
virtual void visit(AstNodeModule* nodep) {
m_modp = nodep;
m_inModOff = nodep->isTop(); // Ignore coverage on top module; it's a shell we created
m_fileps.clear();
iterateChildren(nodep);
m_modp = NULL;
m_inModOff = true;
}
// VISITORS - TOGGLE COVERAGE
virtual void visit(AstNodeFTask* nodep) {
bool oldtog = m_inToggleOff;
{
m_inToggleOff = true;
iterateChildren(nodep);
}
m_inToggleOff = oldtog;
}
virtual void visit(AstVar* nodep) {
iterateChildren(nodep);
if (m_modp && !m_inModOff && !m_inToggleOff
&& nodep->fileline()->coverageOn() && v3Global.opt.coverageToggle()) {
const char* disablep = varIgnoreToggle(nodep);
if (disablep) {
UINFO(4, " Disable Toggle: "<<disablep<<" "<<nodep<<endl);
} else {
UINFO(4, " Toggle: "<<nodep<<endl);
// There's several overall ways to approach this
// Treat like tracing, where a end-of-timestamp action sees all changes
// Works ok, but would be quite slow as need to reform vectors before the calls
// Convert to "always @ (posedge signal[#]) coverinc"
// Would mark many signals as clocks, precluding many later optimizations
// Convert to "if (x & !lastx) CoverInc"
// OK, but we couldn't later detect them to schedule where the IFs get called
// Convert to "AstCoverInc(CoverInc...)"
// We'll do this, and make the if(...) coverinc later.
// Add signal to hold the old value
string newvarname = string("__Vtogcov__")+nodep->shortName();
AstVar* chgVarp = new AstVar(nodep->fileline(), AstVarType::MODULETEMP, newvarname, nodep);
chgVarp->fileline()->modifyWarnOff(V3ErrorCode::UNUSED, true);
m_modp->addStmtp(chgVarp);
// Create bucket for each dimension * bit.
// This is necessarily an O(n^2) expansion, which is why
// we limit coverage to signals with < 256 bits.
ToggleEnt newvec (string(""),
new AstVarRef(nodep->fileline(), nodep, false),
new AstVarRef(nodep->fileline(), chgVarp, true));
toggleVarRecurse(nodep->dtypeSkipRefp(), 0, newvec,
nodep, chgVarp);
newvec.cleanup();
}
}
}
void toggleVarBottom(AstNodeDType* dtypep, int depth, // per-iteration
const ToggleEnt& above,
AstVar* varp, AstVar* chgVarp) { // Constant
AstCoverToggle* newp
= new AstCoverToggle(varp->fileline(),
newCoverInc(varp->fileline(), "", "v_toggle",
varp->name()+above.m_comment),
above.m_varRefp->cloneTree(true),
above.m_chgRefp->cloneTree(true));
m_modp->addStmtp(newp);
}
void toggleVarRecurse(AstNodeDType* dtypep, int depth, // per-iteration
const ToggleEnt& above,
AstVar* varp, AstVar* chgVarp) { // Constant
if (const AstBasicDType* bdtypep = VN_CAST(dtypep, BasicDType)) {
if (bdtypep->isRanged()) {
for (int index_docs=bdtypep->lsb(); index_docs<bdtypep->msb()+1; index_docs++) {
int index_code = index_docs - bdtypep->lsb();
ToggleEnt newent (above.m_comment+string("[")+cvtToStr(index_docs)+"]",
new AstSel(varp->fileline(), above.m_varRefp->cloneTree(true), index_code, 1),
new AstSel(varp->fileline(), above.m_chgRefp->cloneTree(true), index_code, 1));
toggleVarBottom(dtypep, depth+1,
newent,
varp, chgVarp);
newent.cleanup();
}
} else {
toggleVarBottom(dtypep, depth+1,
above,
varp, chgVarp);
}
}
else if (AstUnpackArrayDType* adtypep = VN_CAST(dtypep, UnpackArrayDType)) {
for (int index_docs=adtypep->lsb(); index_docs<=adtypep->msb(); ++index_docs) {
int index_code = index_docs - adtypep->lsb();
ToggleEnt newent (above.m_comment+string("[")+cvtToStr(index_docs)+"]",
new AstArraySel(varp->fileline(), above.m_varRefp->cloneTree(true), index_code),
new AstArraySel(varp->fileline(), above.m_chgRefp->cloneTree(true), index_code));
toggleVarRecurse(adtypep->subDTypep()->skipRefp(), depth+1,
newent,
varp, chgVarp);
newent.cleanup();
}
}
else if (AstPackArrayDType* adtypep = VN_CAST(dtypep, PackArrayDType)) {
for (int index_docs=adtypep->lsb(); index_docs<=adtypep->msb(); ++index_docs) {
AstNodeDType* subtypep = adtypep->subDTypep()->skipRefp();
int index_code = index_docs - adtypep->lsb();
ToggleEnt newent (above.m_comment+string("[")+cvtToStr(index_docs)+"]",
new AstSel(varp->fileline(), above.m_varRefp->cloneTree(true),
index_code*subtypep->width(), subtypep->width()),
new AstSel(varp->fileline(), above.m_chgRefp->cloneTree(true),
index_code*subtypep->width(), subtypep->width()));
toggleVarRecurse(adtypep->subDTypep()->skipRefp(), depth+1,
newent,
varp, chgVarp);
newent.cleanup();
}
}
else if (AstStructDType* adtypep = VN_CAST(dtypep, StructDType)) {
// For now it's packed, so similar to array
for (AstMemberDType* itemp = adtypep->membersp(); itemp; itemp=VN_CAST(itemp->nextp(), MemberDType)) {
AstNodeDType* subtypep = itemp->subDTypep()->skipRefp();
int index_code = itemp->lsb();
ToggleEnt newent (above.m_comment+string(".")+itemp->name(),
new AstSel(varp->fileline(), above.m_varRefp->cloneTree(true),
index_code, subtypep->width()),
new AstSel(varp->fileline(), above.m_chgRefp->cloneTree(true),
index_code, subtypep->width()));
toggleVarRecurse(subtypep, depth+1,
newent,
varp, chgVarp);
newent.cleanup();
}
}
else if (AstUnionDType* adtypep = VN_CAST(dtypep, UnionDType)) {
// Arbitrarially handle only the first member of the union
if (AstMemberDType* itemp = adtypep->membersp()) {
AstNodeDType* subtypep = itemp->subDTypep()->skipRefp();
ToggleEnt newent (above.m_comment+string(".")+itemp->name(),
above.m_varRefp->cloneTree(true),
above.m_chgRefp->cloneTree(true));
toggleVarRecurse(subtypep, depth+1,
newent,
varp, chgVarp);
newent.cleanup();
}
}
else {
dtypep->v3fatalSrc("Unexpected node data type in toggle coverage generation: "<<dtypep->prettyTypeName());
}
}
// VISITORS - LINE COVERAGE
virtual void visit(AstIf* nodep) { // Note not AstNodeIf; other types don't get covered
UINFO(4," IF: "<<nodep<<endl);
if (m_checkBlock) {
// An else-if. When we iterate the if, use "elsif" marking
bool elsif = (VN_IS(nodep->elsesp(), If)
&& !VN_CAST(nodep->elsesp(), If)->nextp());
if (elsif) VN_CAST(nodep->elsesp(), If)->user1(true);
//
iterateAndNextNull(nodep->ifsp());
if (m_checkBlock && !m_inModOff
&& nodep->fileline()->coverageOn() && v3Global.opt.coverageLine()) { // if a "if" branch didn't disable it
UINFO(4," COVER: "<<nodep<<endl);
if (nodep->user1()) {
nodep->addIfsp(newCoverInc(nodep->fileline(), "", "v_line", "elsif"));
} else {
nodep->addIfsp(newCoverInc(nodep->fileline(), "", "v_line", "if"));
}
}
// Don't do empty else's, only empty if/case's
if (nodep->elsesp()) {
m_checkBlock = true;
iterateAndNextNull(nodep->elsesp());
if (m_checkBlock && !m_inModOff
&& nodep->fileline()->coverageOn() && v3Global.opt.coverageLine()) { // if a "else" branch didn't disable it
UINFO(4," COVER: "<<nodep<<endl);
if (!elsif) { // elsif done inside if()
nodep->addElsesp(newCoverInc(nodep->elsesp()->fileline(), "", "v_line", "else"));
}
}
}
m_checkBlock = true; // Reset as a child may have cleared it
}
}
virtual void visit(AstCaseItem* nodep) {
UINFO(4," CASEI: "<<nodep<<endl);
if (m_checkBlock && !m_inModOff
&& nodep->fileline()->coverageOn() && v3Global.opt.coverageLine()) {
iterateAndNextNull(nodep->bodysp());
if (m_checkBlock) { // if the case body didn't disable it
UINFO(4," COVER: "<<nodep<<endl);
nodep->addBodysp(newCoverInc(nodep->fileline(), "", "v_line", "case"));
}
m_checkBlock = true; // Reset as a child may have cleared it
}
}
virtual void visit(AstPslCover* nodep) {
UINFO(4," PSLCOVER: "<<nodep<<endl);
m_checkBlock = true; // Always do cover blocks, even if there's a $stop
iterateChildren(nodep);
if (!nodep->coverincp()) {
// Note the name may be overridden by V3Assert processing
nodep->coverincp(newCoverInc(nodep->fileline(), m_beginHier, "v_user", "cover"));
}
m_checkBlock = true; // Reset as a child may have cleared it
}
virtual void visit(AstStop* nodep) {
UINFO(4," STOP: "<<nodep<<endl);
m_checkBlock = false;
}
virtual void visit(AstPragma* nodep) {
if (nodep->pragType() == AstPragmaType::COVERAGE_BLOCK_OFF) {
// Skip all NEXT nodes under this block, and skip this if/case branch
UINFO(4," OFF: "<<nodep<<endl);
m_checkBlock = false;
nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
} else {
if (m_checkBlock) iterateChildren(nodep);
}
}
virtual void visit(AstBegin* nodep) {
// Record the hierarchy of any named begins, so we can apply to user
// coverage points. This is because there may be cov points inside
// generate blocks; each point should get separate consideration.
// (Currently ignored for line coverage, since any generate iteration
// covers the code in that line.)
string oldHier = m_beginHier;
bool oldtog = m_inToggleOff;
{
m_inToggleOff = true;
if (nodep->name()!="") {
m_beginHier = m_beginHier + (m_beginHier!=""?".":"") + nodep->name();
}
iterateChildren(nodep);
}
m_beginHier = oldHier;
m_inToggleOff = oldtog;
}
// VISITORS - BOTH
virtual void visit(AstNode* nodep) {
// Default: Just iterate
if (m_checkBlock) {
iterateChildren(nodep);
m_checkBlock = true; // Reset as a child may have cleared it
}
}
public:
// CONSTUCTORS
explicit CoverageVisitor(AstNetlist* rootp) {
// Operate on all modules
m_checkBlock = true;
m_modp = NULL;
m_beginHier = "";
m_inToggleOff = false;
m_inModOff = true;
iterateChildren(rootp);
}
virtual ~CoverageVisitor() {}
};
//######################################################################
// Coverage class functions
void V3Coverage::coverage(AstNetlist* rootp) {
UINFO(2,__FUNCTION__<<": "<<endl);
{
CoverageVisitor visitor (rootp);
} // Destruct before checking
V3Global::dumpCheckGlobalTree("coverage", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
}