verilator/src/V3Coverage.cpp

1035 lines
45 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Netlist (top level) functions
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2003-2025 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.
// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
//
//*************************************************************************
// 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 "V3PchAstNoMT.h" // VL_MT_DISABLED_CODE_UNIT
#include "V3Coverage.h"
#include "V3EmitV.h"
#include <list>
#include <unordered_map>
VL_DEFINE_DEBUG_FUNCTIONS;
class ExprCoverageEligibleVisitor final : public VNVisitor {
// STATE
bool m_eligible = true;
void visit(AstNodeVarRef* nodep) override {
AstNodeDType* dtypep = nodep->varp()->dtypep();
// Class objecs and references not supported for expression coverage
// because the object may not persist until the point at which
// coverage data is gathered
// This could be resolved in the future by protecting against dereferrencing
// null pointers when cloning the expression for expression coverage
if (VN_CAST(dtypep, ClassRefDType)) {
m_eligible = false;
} else {
iterateChildren(nodep);
}
}
void visit(AstNode* nodep) override {
if (!nodep->isExprCoverageEligible()) {
m_eligible = false;
} else {
iterateChildren(nodep);
}
}
public:
// CONSTRUCTORS
explicit ExprCoverageEligibleVisitor(AstNode* nodep) { iterateChildren(nodep); }
~ExprCoverageEligibleVisitor() override = default;
bool eligible() { return m_eligible; }
};
//######################################################################
// Coverage state, as a visitor of each AstNode
class CoverageVisitor final : public VNVisitor {
// TYPES
using LinenoSet = std::set<int>;
struct CoverTerm final {
AstNodeExpr* m_exprp; // Expression branch term
bool m_objective; // Term objective
std::string m_emitV; // V3EmitV string for cover point comment
CoverTerm(AstNodeExpr* exprp, bool objective, const string& emitV)
: m_exprp{exprp}
, m_objective{objective}
, m_emitV(emitV) {}
};
using CoverExpr = std::deque<CoverTerm>;
using CoverExprs = std::list<CoverExpr>;
struct ToggleEnt final {
const string m_comment; // Comment for coverage dump
AstNodeExpr* m_varRefp; // How to get to this element
AstNodeExpr* m_chgRefp; // How to get to this element
ToggleEnt(const string& comment, AstNodeExpr* vp, AstNodeExpr* cp)
: m_comment{comment}
, m_varRefp{vp}
, m_chgRefp{cp} {}
~ToggleEnt() = default;
void cleanup() {
VL_DO_CLEAR(m_varRefp->deleteTree(), m_varRefp = nullptr);
VL_DO_CLEAR(m_chgRefp->deleteTree(), m_chgRefp = nullptr);
}
};
struct CheckState final { // State save-restored on each new coverage scope/block
bool m_on = false; // Should this block get covered?
bool m_inModOff = false; // In module with no coverage
int m_handle = 0; // Opaque handle for index into line tracking
const AstNode* m_nodep = nullptr; // Node establishing this state
CheckState() = default;
bool lineCoverageOn(const AstNode* nodep) const {
return m_on && !m_inModOff && nodep->fileline()->coverageOn()
&& v3Global.opt.coverageLine();
}
bool exprCoverageOn(const AstNode* nodep) const {
return m_on && !m_inModOff && nodep->fileline()->coverageOn()
&& v3Global.opt.coverageExpr();
}
};
enum Objective : uint8_t { NONE, SEEKING, ABORTED };
// NODE STATE
// Entire netlist:
// AstIf::user1() -> bool. True indicates ifelse processed
// AstIf::user2() -> bool. True indicates coverage-generated
const VNUser1InUse m_inuser1;
const VNUser2InUse m_inuser2;
// STATE - across all visitors
int m_nextHandle = 0;
// STATE - for current visit position (use VL_RESTORER)
CheckState m_state; // State save-restored on each new coverage scope/block
AstNodeModule* m_modp = nullptr; // Current module to add statement to
AstNode* m_exprStmtsp = nullptr; // Node to add expr coverage to
bool m_then = false; // Whether we're iterating the then or else branch
// when m_exprStmtps is an AstIf
CoverExprs m_exprs; // List of expressions that can reach objective
Objective m_seeking = NONE; // Seeking objective for expression coverage
bool m_objective = false; // Expression objective
bool m_ifCond = false; // Visiting if condition
bool m_inToggleOff = false; // In function/task etc
bool m_inLoopNotBody = false; // Inside a loop, but not in its body
string m_beginHier; // AstBegin hier name for user coverage points
// STATE - cleared each module
std::unordered_map<std::string, uint32_t> m_varnames; // Uniquify inserted variable names
std::unordered_map<int, LinenoSet> m_handleLines; // Line numbers for given m_stateHandle
// METHODS
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()) {
const 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())
> static_cast<uint32_t>(v3Global.opt.coverageMaxWidth())) {
return "Wide bus/array > --coverage-max-width setting's bits";
}
// We allow this, though tracing doesn't
// if (nodep->arrayp(1)) return "Unsupported: Multi-dimensional array";
return nullptr;
}
AstCoverInc* newCoverInc(FileLine* fl, const string& hier, const string& page_prefix,
const string& comment, const string& linescov, int offset,
const string& trace_var_name) {
// 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
const string page = page_prefix + "/" + m_modp->prettyName();
AstCoverDecl* const declp = new AstCoverDecl{fl, page, comment, linescov, offset};
declp->hier(hier);
m_modp->addStmtsp(declp);
UINFO(9, "new " << declp);
AstCoverInc* const incp = new AstCoverInc{fl, declp};
if (!trace_var_name.empty()
&& v3Global.opt.traceCoverage()
// No module handle to trace inside classes
&& !VN_IS(m_modp, Class)) {
FileLine* const fl_nowarn = new FileLine{incp->fileline()};
fl_nowarn->modifyWarnOff(V3ErrorCode::UNUSEDSIGNAL, true);
AstVar* const varp = new AstVar{fl_nowarn, VVarType::MODULETEMP, trace_var_name,
incp->findUInt32DType()};
varp->setIgnoreSchedWrite(); // Ignore the increment output, so no UNOPTFLAT
varp->trace(true);
m_modp->addStmtsp(varp);
UINFO(5, "New coverage trace: " << varp);
AstAssign* const assp = new AstAssign{
incp->fileline(), new AstVarRef{incp->fileline(), varp, VAccess::WRITE},
new AstAdd{incp->fileline(), new AstVarRef{incp->fileline(), varp, VAccess::READ},
new AstConst{incp->fileline(), AstConst::WidthedValue{}, 32, 1}}};
AstNode::addNext<AstNode, AstNode>(incp, assp);
}
return incp;
}
string traceNameForLine(AstNode* nodep, const string& type) {
string name = "vlCoverageLineTrace_" + nodep->fileline()->filebasenameNoExt() + "__"
+ cvtToStr(nodep->fileline()->lineno()) + "_" + type;
if (const uint32_t suffix = m_varnames[name]++) name += "_" + cvtToStr(suffix);
return name;
}
// Line tracking
void createHandle(const AstNode* nodep) {
// Start tracking lines for the given handling node
// If and if's else have separate handles for same nodep,
// so nodep cannot have a pointer to a unique handle
m_state.m_on = true;
m_state.m_handle = ++m_nextHandle;
// Ensure line numbers we track are in the same file as this block
// so track via nodep
m_state.m_nodep = nodep;
UINFO(9, "line create h" << m_state.m_handle << " " << nodep);
}
void lineTrack(const AstNode* nodep) {
if (m_state.lineCoverageOn(nodep) && !m_ifCond
&& m_state.m_nodep->fileline()->filenameno() == nodep->fileline()->filenameno()) {
for (int lineno = nodep->fileline()->firstLineno();
lineno <= nodep->fileline()->lastLineno(); ++lineno) {
UINFO(9, "line track " << lineno << " for h" << m_state.m_handle << " "
<< m_state.m_nodep);
m_handleLines[m_state.m_handle].insert(lineno);
}
}
}
static string linesFirstLast(const int first, const int last) {
if (first && first == last) {
return cvtToStr(first);
} else if (first && last) {
return cvtToStr(first) + "-" + cvtToStr(last);
} else {
return "";
}
}
string linesCov(const CheckState& state, const AstNode* nodep) {
// Return comma separated list of ranged numbers
string out;
const LinenoSet& lines = m_handleLines[state.m_handle];
int first = 0;
int last = 0;
for (int linen : lines) {
if (!first) {
first = last = linen;
} else if (linen == last + 1) {
++last;
} else {
if (!out.empty()) out += ",";
out += linesFirstLast(first, last);
first = last = linen;
}
}
if (first) {
if (!out.empty()) out += ",";
out += linesFirstLast(first, last);
}
UINFO(9, "lines out " << out << " for h" << state.m_handle << " " << nodep);
return out;
}
// VISITORS - BOTH
void visit(AstNodeModule* nodep) override {
const AstNodeModule* const origModp = m_modp;
VL_RESTORER(m_modp);
VL_RESTORER(m_state);
createHandle(nodep);
m_modp = nodep;
m_state.m_inModOff
= nodep->isTop(); // Ignore coverage on top module; it's a shell we created
if (!origModp) {
// No blocks cross (non-nested) modules, so save some memory
m_varnames.clear();
m_handleLines.clear();
}
iterateChildren(nodep);
}
void visit(AstNodeProcedure* nodep) override { iterateProcedure(nodep); }
// we can cover expressions in while loops, but the counting goes outside
// the while, see: "minimally-intelligent decision about ... clock domain"
// in the Toggle Coverage docs
void visit(AstWhile* nodep) override {
VL_RESTORER(m_state);
VL_RESTORER(m_inToggleOff);
m_inToggleOff = true;
createHandle(nodep);
{
VL_RESTORER(m_inLoopNotBody);
m_inLoopNotBody = true;
iterateAndNextNull(nodep->precondsp());
iterateNull(nodep->condp());
iterateAndNextNull(nodep->incsp());
}
iterateAndNextNull(nodep->stmtsp());
if (m_state.lineCoverageOn(nodep)) {
lineTrack(nodep);
AstNode* const newp
= newCoverInc(nodep->fileline(), "", "v_line", "block", linesCov(m_state, nodep),
0, traceNameForLine(nodep, "block"));
insertProcStatement(nodep, newp);
}
}
void visit(AstNodeFTask* nodep) override {
if (!nodep->dpiImport()) iterateProcedure(nodep);
}
void insertProcStatement(AstNode* nodep, AstNode* stmtp) {
if (AstNodeProcedure* const itemp = VN_CAST(nodep, NodeProcedure)) {
itemp->addStmtsp(stmtp);
} else if (AstNodeFTask* const itemp = VN_CAST(nodep, NodeFTask)) {
itemp->addStmtsp(stmtp);
} else if (AstWhile* const itemp = VN_CAST(nodep, While)) {
itemp->addStmtsp(stmtp);
} else if (AstIf* const itemp = VN_CAST(nodep, If)) {
if (m_then) {
itemp->addThensp(stmtp);
} else {
itemp->addElsesp(stmtp);
}
} else {
nodep->v3fatalSrc("Bad node type");
}
}
void iterateProcedure(AstNode* nodep) {
VL_RESTORER(m_state);
VL_RESTORER(m_exprStmtsp);
VL_RESTORER(m_inToggleOff);
m_exprStmtsp = nodep;
m_inToggleOff = true;
createHandle(nodep);
iterateChildren(nodep);
if (m_state.lineCoverageOn(nodep)) {
lineTrack(nodep);
AstNode* const newp
= newCoverInc(nodep->fileline(), "", "v_line", "block", linesCov(m_state, nodep),
0, traceNameForLine(nodep, "block"));
insertProcStatement(nodep, newp);
}
}
// VISITORS - TOGGLE COVERAGE
void visit(AstVar* nodep) override {
iterateChildren(nodep);
if (m_modp && !m_inToggleOff && !m_state.m_inModOff && nodep->fileline()->coverageOn()
&& v3Global.opt.coverageToggle()) {
const char* const disablep = varIgnoreToggle(nodep);
if (disablep) {
UINFO(4, " Disable Toggle: " << disablep << " " << nodep);
} else {
UINFO(4, " Toggle: " << nodep);
// 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
const string newvarname = "__Vtogcov__"s + m_beginHier + nodep->shortName();
FileLine* const fl_nowarn = new FileLine{nodep->fileline()};
fl_nowarn->modifyWarnOff(V3ErrorCode::UNUSEDSIGNAL, true);
AstVar* const chgVarp
= new AstVar{fl_nowarn, VVarType::MODULETEMP, newvarname, nodep};
m_modp->addStmtsp(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{""s, new AstVarRef{fl_nowarn, nodep, VAccess::READ},
new AstVarRef{fl_nowarn, chgVarp, VAccess::WRITE}};
toggleVarRecurse(nodep->dtypeSkipRefp(), 0, newvec, nodep);
newvec.cleanup();
}
}
}
void toggleVarBottom(const ToggleEnt& above, const AstVar* varp) {
const std::string hierPrefix
= (m_beginHier != "") ? AstNode::prettyName(m_beginHier) + "." : "";
AstCoverToggle* const newp = new AstCoverToggle{
varp->fileline(),
newCoverInc(varp->fileline(), "", "v_toggle",
hierPrefix + varp->name() + above.m_comment, "", 0, ""),
above.m_varRefp->cloneTree(false), above.m_chgRefp->cloneTree(false)};
m_modp->addStmtsp(newp);
}
void toggleVarRecurse(const AstNodeDType* const dtypep, const int depth, // per-iteration
const ToggleEnt& above, const AstVar* const varp) { // Constant
if (const AstBasicDType* const bdtypep = VN_CAST(dtypep, BasicDType)) {
if (bdtypep->isRanged()) {
for (int index_docs = bdtypep->lo(); index_docs < bdtypep->hi() + 1;
++index_docs) {
const int index_code = index_docs - bdtypep->lo();
ToggleEnt newent{above.m_comment + "["s + cvtToStr(index_docs) + "]",
new AstSel{varp->fileline(),
above.m_varRefp->cloneTree(false), index_code, 1},
new AstSel{varp->fileline(),
above.m_chgRefp->cloneTree(false), index_code, 1}};
toggleVarBottom(newent, varp);
newent.cleanup();
}
} else {
toggleVarBottom(above, varp);
}
} else if (const AstUnpackArrayDType* const adtypep = VN_CAST(dtypep, UnpackArrayDType)) {
for (int index_docs = adtypep->lo(); index_docs <= adtypep->hi(); ++index_docs) {
const int index_code = index_docs - adtypep->lo();
ToggleEnt newent{above.m_comment + "["s + cvtToStr(index_docs) + "]",
new AstArraySel{varp->fileline(),
above.m_varRefp->cloneTree(false), index_code},
new AstArraySel{varp->fileline(),
above.m_chgRefp->cloneTree(false), index_code}};
toggleVarRecurse(adtypep->subDTypep()->skipRefp(), depth + 1, newent, varp);
newent.cleanup();
}
} else if (const AstPackArrayDType* const adtypep = VN_CAST(dtypep, PackArrayDType)) {
for (int index_docs = adtypep->lo(); index_docs <= adtypep->hi(); ++index_docs) {
const AstNodeDType* const subtypep = adtypep->subDTypep()->skipRefp();
const int index_code = index_docs - adtypep->lo();
ToggleEnt newent{above.m_comment + "["s + cvtToStr(index_docs) + "]",
new AstSel{varp->fileline(), above.m_varRefp->cloneTree(false),
index_code * subtypep->width(), subtypep->width()},
new AstSel{varp->fileline(), above.m_chgRefp->cloneTree(false),
index_code * subtypep->width(), subtypep->width()}};
toggleVarRecurse(adtypep->subDTypep()->skipRefp(), depth + 1, newent, varp);
newent.cleanup();
}
} else if (const AstStructDType* const adtypep = VN_CAST(dtypep, StructDType)) {
if (adtypep->packed()) {
for (AstMemberDType* itemp = adtypep->membersp(); itemp;
itemp = VN_AS(itemp->nextp(), MemberDType)) {
AstNodeDType* const subtypep = itemp->subDTypep()->skipRefp();
const int index_code = itemp->lsb();
ToggleEnt newent{
above.m_comment + "."s + itemp->name(),
new AstSel{varp->fileline(), above.m_varRefp->cloneTree(false), index_code,
subtypep->width()},
new AstSel{varp->fileline(), above.m_chgRefp->cloneTree(false), index_code,
subtypep->width()}};
toggleVarRecurse(subtypep, depth + 1, newent, varp);
newent.cleanup();
}
} else {
for (AstMemberDType* itemp = adtypep->membersp(); itemp;
itemp = VN_AS(itemp->nextp(), MemberDType)) {
AstNodeDType* const subtypep = itemp->subDTypep()->skipRefp();
AstNodeExpr* const varRefp = new AstStructSel{
varp->fileline(), above.m_varRefp->cloneTree(false), itemp->name()};
AstNodeExpr* const chgRefp = new AstStructSel{
varp->fileline(), above.m_chgRefp->cloneTree(false), itemp->name()};
varRefp->dtypep(subtypep);
chgRefp->dtypep(subtypep);
ToggleEnt newent{above.m_comment + "."s + itemp->name(), varRefp, chgRefp};
toggleVarRecurse(subtypep, depth + 1, newent, varp);
newent.cleanup();
}
}
} else if (const AstUnionDType* const adtypep = VN_CAST(dtypep, UnionDType)) {
// Arbitrarily handle only the first member of the union
if (const AstMemberDType* const itemp = adtypep->membersp()) {
AstNodeDType* const subtypep = itemp->subDTypep()->skipRefp();
if (adtypep->packed()) {
ToggleEnt newent{above.m_comment + "."s + itemp->name(),
above.m_varRefp->cloneTree(false),
above.m_chgRefp->cloneTree(false)};
toggleVarRecurse(subtypep, depth + 1, newent, varp);
newent.cleanup();
} else {
AstNodeExpr* const varRefp = new AstStructSel{
varp->fileline(), above.m_varRefp->cloneTree(false), itemp->name()};
AstNodeExpr* const chgRefp = new AstStructSel{
varp->fileline(), above.m_chgRefp->cloneTree(false), itemp->name()};
varRefp->dtypep(subtypep);
chgRefp->dtypep(subtypep);
ToggleEnt newent{above.m_comment + "."s + itemp->name(), varRefp, chgRefp};
toggleVarRecurse(subtypep, depth + 1, newent, varp);
newent.cleanup();
}
}
} else if (VN_IS(dtypep, QueueDType)) {
// Not covered
} else {
dtypep->v3fatalSrc("Unexpected node data type in toggle coverage generation: "
<< dtypep->prettyTypeName());
}
}
bool includeCondToBranchRecursive(const AstNode* const nodep) {
const AstNode* const backp = nodep->backp();
if (VN_IS(backp, Cond) && VN_AS(backp, Cond)->condp() != nodep) {
return includeCondToBranchRecursive(backp);
} else if (VN_IS(backp, Sel) && VN_AS(backp, Sel)->fromp() == nodep) {
return includeCondToBranchRecursive(backp);
} else if (VN_IS(backp, NodeAssign) && VN_AS(backp, NodeAssign)->rhsp() == nodep
&& !m_inLoopNotBody) {
return true;
}
return false;
}
// VISITORS - LINE COVERAGE
void visit(AstCond* nodep) override {
UINFO(4, " COND: " << nodep);
if (m_seeking == NONE) coverExprs(nodep->condp());
if (m_state.lineCoverageOn(nodep) && VN_IS(m_modp, Module)
&& includeCondToBranchRecursive(nodep)) {
VL_RESTORER(m_seeking);
// Disable expression coverage in sub-expressions, since they were already visited
m_seeking = ABORTED;
const CheckState lastState = m_state;
createHandle(nodep);
iterate(nodep->thenp());
lineTrack(nodep);
AstNodeExpr* const thenp = nodep->thenp()->unlinkFrBack();
nodep->thenp(new AstExprStmt{thenp->fileline(),
newCoverInc(nodep->fileline(), "", "v_branch",
"cond_then", linesCov(m_state, nodep), 0,
traceNameForLine(nodep, "cond_then")),
thenp});
m_state = lastState;
createHandle(nodep);
iterate(nodep->elsep());
AstNodeExpr* const elsep = nodep->elsep()->unlinkFrBack();
nodep->elsep(new AstExprStmt{elsep->fileline(),
newCoverInc(nodep->fileline(), "", "v_branch",
"cond_else", linesCov(m_state, nodep), 1,
traceNameForLine(nodep, "cond_else")),
elsep});
m_state = lastState;
} else {
lineTrack(nodep);
}
}
// Note not AstNodeIf; other types don't get covered
void visit(AstIf* nodep) override {
if (nodep->user2()) return;
UINFO(4, " IF: " << nodep);
if (m_state.m_on) {
// An else-if. When we iterate the if, use "elsif" marking
const bool elsif
= nodep->thensp() && VN_IS(nodep->elsesp(), If) && !nodep->elsesp()->nextp();
if (elsif) VN_AS(nodep->elsesp(), If)->user1(true);
const bool first_elsif = !nodep->user1() && elsif;
const bool cont_elsif = nodep->user1() && elsif;
const bool final_elsif = nodep->user1() && !elsif && nodep->elsesp();
//
// Considered: If conditional is on a different line from if/else then we
// can show it as part of line coverage of the statement
// above. Otherwise show it based on what is inside.
// But: Seemed too complicated, and fragile.
const CheckState lastState = m_state;
CheckState ifState;
CheckState elseState;
{
VL_RESTORER(m_exprStmtsp);
VL_RESTORER(m_then);
m_exprStmtsp = nodep;
m_then = true;
createHandle(nodep);
iterateAndNextNull(nodep->thensp());
lineTrack(nodep);
ifState = m_state;
}
m_state = lastState;
{
VL_RESTORER(m_exprStmtsp);
VL_RESTORER(m_then);
m_exprStmtsp = nodep;
m_then = false;
createHandle(nodep);
iterateAndNextNull(nodep->elsesp());
elseState = m_state;
}
m_state = lastState;
//
// If both if and else are "on", and we're not in an if/else, then
// we do branch coverage
if (!(first_elsif || cont_elsif || final_elsif) && ifState.lineCoverageOn(nodep)
&& elseState.lineCoverageOn(nodep)) {
// Normal if. Linecov shows what's inside the if (not condition that is
// always executed)
UINFO(4, " COVER-branch: " << nodep);
nodep->addThensp(newCoverInc(nodep->fileline(), "", "v_branch", "if",
linesCov(ifState, nodep), 0,
traceNameForLine(nodep, "if")));
// The else has a column offset of 1 to uniquify it relative to the if
// As "if" and "else" are more than one character wide, this won't overlap
// another token
nodep->addElsesp(newCoverInc(nodep->fileline(), "", "v_branch", "else",
linesCov(elseState, nodep), 1,
traceNameForLine(nodep, "else")));
}
// If/else attributes to each block as non-branch coverage
else if (first_elsif || cont_elsif) {
UINFO(4, " COVER-elsif: " << nodep);
if (ifState.lineCoverageOn(nodep)) {
nodep->addThensp(newCoverInc(nodep->fileline(), "", "v_line", "elsif",
linesCov(ifState, nodep), 0,
traceNameForLine(nodep, "elsif")));
}
// and we don't insert the else as the child if-else will do so
} else {
// Cover as separate blocks (not a branch as is not two-legged)
if (ifState.lineCoverageOn(nodep)) {
UINFO(4, " COVER-half-if: " << nodep);
nodep->addThensp(newCoverInc(nodep->fileline(), "", "v_line", "if",
linesCov(ifState, nodep), 0,
traceNameForLine(nodep, "if")));
}
if (elseState.lineCoverageOn(nodep)) {
UINFO(4, " COVER-half-el: " << nodep);
nodep->addElsesp(newCoverInc(nodep->fileline(), "", "v_line", "else",
linesCov(elseState, nodep), 1,
traceNameForLine(nodep, "else")));
}
}
m_state = lastState;
}
VL_RESTORER(m_ifCond);
m_ifCond = true;
iterateAndNextNull(nodep->condp());
UINFO(9, " done HANDLE " << m_state.m_handle << " for " << nodep);
}
void visit(AstCaseItem* nodep) override {
// We don't add an explicit "default" coverage if not provided,
// as we already have a warning when there is no default.
UINFO(4, " CASEI: " << nodep);
if (m_state.lineCoverageOn(nodep)) {
VL_RESTORER(m_state);
createHandle(nodep);
iterateAndNextNull(nodep->stmtsp());
if (m_state.lineCoverageOn(nodep)) { // if the case body didn't disable it
lineTrack(nodep);
UINFO(4, " COVER: " << nodep);
nodep->addStmtsp(newCoverInc(nodep->fileline(), "", "v_line", "case",
linesCov(m_state, nodep), 0,
traceNameForLine(nodep, "case")));
}
}
}
void visit(AstCover* nodep) override {
UINFO(4, " COVER: " << nodep);
VL_RESTORER(m_state);
m_state.m_on = true; // Always do cover blocks, even if there's a $stop
createHandle(nodep);
iterateChildren(nodep);
if (!nodep->coverincsp() && v3Global.opt.coverageUser()) {
// Note the name may be overridden by V3Assert processing
lineTrack(nodep);
nodep->addCoverincsp(newCoverInc(nodep->fileline(), m_beginHier, "v_user", "cover",
linesCov(m_state, nodep), 0,
m_beginHier + "_vlCoverageUserTrace"));
}
}
void visit(AstStop* nodep) override {
UINFO(4, " STOP: " << nodep);
m_state.m_on = false;
}
void visit(AstPragma* nodep) override {
if (nodep->pragType() == VPragmaType::COVERAGE_BLOCK_OFF) {
// Skip all NEXT nodes under this block, and skip this if/case branch
UINFO(4, " OFF: h" << m_state.m_handle << " " << nodep);
m_state.m_on = false;
VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
} else {
if (m_state.m_on) iterateChildren(nodep);
lineTrack(nodep);
}
}
void visit(AstBegin* nodep) override {
// 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.)
VL_RESTORER(m_beginHier);
VL_RESTORER(m_inToggleOff);
if (!nodep->generate()) m_inToggleOff = true;
if (nodep->name() != "") {
m_beginHier = m_beginHier + (m_beginHier != "" ? "__DOT__" : "") + nodep->name();
}
iterateChildren(nodep);
lineTrack(nodep);
}
void abortExprCoverage() {
// is possible to hit max while in NONE, see: exprReduce()
// if that happens we don't want to set ABORTED if it isn't already
// since that will bleed into other expressions
if (m_seeking != NONE) m_seeking = ABORTED;
m_exprs.clear();
}
bool checkMaxExprs(size_t additional = 0) {
if (m_seeking != ABORTED
&& static_cast<int>(m_exprs.size() + additional) <= v3Global.opt.coverageExprMax())
return false;
abortExprCoverage();
return true;
}
void addExprCoverInc(AstNodeExpr* nodep, int start = 0) {
FileLine* const fl = nodep->fileline();
int count = start;
for (CoverExpr& expr : m_exprs) {
const string name = "expr_" + std::to_string(count);
string comment = "(";
bool first = true;
AstNodeExpr* condp = nullptr;
for (CoverTerm& term : expr) {
comment += (first ? "" : " && ") + term.m_emitV
+ "==" + (term.m_objective ? "1" : "0");
AstNodeExpr* const clonep = term.m_exprp->cloneTree(false);
AstNodeExpr* const termp = term.m_objective ? clonep : new AstLogNot{fl, clonep};
if (condp) {
condp = new AstLogAnd{fl, condp, termp};
} else {
condp = termp;
}
first = false;
}
comment += ") => ";
comment += (m_objective ? '1' : '0');
AstNode* const newp
= newCoverInc(fl, "", "v_expr", comment, "", 0, traceNameForLine(nodep, name));
UASSERT_OBJ(condp, nodep, "No terms in expression coverage branch");
AstIf* const ifp = new AstIf{fl, condp, newp, nullptr};
ifp->user2(true);
insertProcStatement(m_exprStmtsp, ifp);
++count;
}
}
void coverExprs(AstNodeExpr* nodep) {
if (!m_state.exprCoverageOn(nodep) || nodep->dtypep()->width() != 1 || !m_exprStmtsp) {
return;
}
UASSERT_OBJ(m_seeking == NONE, nodep, "recursively covering expressions is not expected");
UASSERT_OBJ(m_exprs.empty(), nodep, "unexpected expression coverage garbage");
VL_RESTORER(m_seeking);
VL_RESTORER(m_objective);
VL_RESTORER(m_exprs);
m_seeking = SEEKING;
m_objective = false;
iterate(nodep);
CoverExprs falseExprs;
m_exprs.swap(falseExprs);
m_objective = true;
iterate(nodep);
if (checkMaxExprs(falseExprs.size())) return;
if (m_seeking == ABORTED) return;
addExprCoverInc(nodep);
const int start = m_exprs.size();
m_objective = false;
m_exprs.swap(falseExprs);
addExprCoverInc(nodep, start);
}
void exprEither(AstNodeBiop* nodep, bool overrideObjective = false, bool lObjective = false,
bool rObjective = false) {
VL_RESTORER(m_objective);
AstNodeExpr* const lhsp = nodep->lhsp();
AstNodeExpr* const rhsp = nodep->rhsp();
if (overrideObjective) m_objective = lObjective;
iterate(lhsp);
if (checkMaxExprs()) return;
CoverExprs lhsExprs;
m_exprs.swap(lhsExprs);
if (overrideObjective) m_objective = rObjective;
iterate(rhsp);
m_exprs.splice(m_exprs.end(), lhsExprs);
checkMaxExprs();
}
void exprBoth(AstNodeBiop* nodep, bool overrideObjective = false, bool lObjective = false,
bool rObjective = false) {
VL_RESTORER(m_objective);
AstNodeExpr* const lhsp = nodep->lhsp();
AstNodeExpr* const rhsp = nodep->rhsp();
if (overrideObjective) m_objective = lObjective;
iterate(lhsp);
if (checkMaxExprs()) return;
CoverExprs lhsExprs;
m_exprs.swap(lhsExprs);
if (overrideObjective) m_objective = rObjective;
iterate(rhsp);
if (checkMaxExprs()) return;
CoverExprs rhsExprs;
m_exprs.swap(rhsExprs);
for (CoverExpr& l : lhsExprs) {
for (CoverExpr& r : rhsExprs) {
// array size 2 -> (false, true)
std::array<std::set<AstVar*>, 2> varps;
std::array<std::set<std::string>, 2> strs;
UASSERT_OBJ(!l.empty() && !r.empty(), nodep, "Empty coverage expression branch");
CoverExpr expr;
// Compare Vars for simple VarRefs otherwise compare stringified terms
// remove redundant terms and remove entire expression branches when
// terms conflict
// Equivalent terms which don't match on either of these criteria will
// not be flagged as redundant or impossible, however the results will
// still be valid, albeit messier
for (CoverTerm& term : l) {
if (AstVarRef* const refp = VN_CAST(term.m_exprp, VarRef)) {
varps[term.m_objective].insert(refp->varp());
} else {
strs[term.m_objective].insert(term.m_emitV);
}
expr.push_back(term);
}
bool impossible = false;
for (CoverTerm& term : r) {
bool redundant = false;
if (AstNodeVarRef* const refp = VN_CAST(term.m_exprp, NodeVarRef)) {
if (varps[term.m_objective].find(refp->varp())
!= varps[term.m_objective].end())
redundant = true;
if (varps[!term.m_objective].find(refp->varp())
!= varps[!term.m_objective].end())
impossible = true;
} else {
if (strs[term.m_objective].find(term.m_emitV)
!= strs[term.m_objective].end())
redundant = true;
if (strs[!term.m_objective].find(term.m_emitV)
!= strs[!term.m_objective].end())
impossible = true;
}
if (!redundant) expr.push_back(term);
}
if (!impossible) m_exprs.push_back(std::move(expr));
if (checkMaxExprs()) return;
}
}
}
void orExpr(AstNodeBiop* nodep) {
if (m_seeking == NONE) {
coverExprs(nodep);
} else if (m_objective) {
exprEither(nodep);
} else {
exprBoth(nodep);
}
lineTrack(nodep);
}
void visit(AstLogOr* nodep) override { orExpr(nodep); }
void visit(AstOr* nodep) override { orExpr(nodep); }
void andExpr(AstNodeBiop* nodep) {
if (m_seeking == NONE) {
coverExprs(nodep);
} else if (m_objective) {
exprBoth(nodep);
} else {
exprEither(nodep);
}
lineTrack(nodep);
}
void visit(AstLogAnd* nodep) override { andExpr(nodep); }
void visit(AstAnd* nodep) override { andExpr(nodep); }
void xorExpr(AstNodeBiop* nodep) {
if (m_seeking == NONE) {
coverExprs(nodep);
} else {
for (const bool lObjective : {false, true}) {
CoverExprs prevExprs;
m_exprs.swap(prevExprs);
const bool rObjective = lObjective ^ m_objective;
exprBoth(nodep, true, lObjective, rObjective);
m_exprs.splice(m_exprs.end(), prevExprs);
if (checkMaxExprs()) break;
}
}
lineTrack(nodep);
}
void visit(AstXor* nodep) override { xorExpr(nodep); }
void exprNot(AstNodeExpr* nodep) {
VL_RESTORER(m_objective);
if (m_seeking == NONE) {
coverExprs(nodep);
} else {
m_objective = !m_objective;
iterateChildren(nodep);
lineTrack(nodep);
}
}
void visit(AstNot* nodep) override { exprNot(nodep); }
void visit(AstLogNot* nodep) override { exprNot(nodep); }
template <typename T_Oper>
void exprReduce(AstNodeUniop* nodep) {
if (m_seeking != ABORTED) {
FileLine* const fl = nodep->fileline();
AstNodeExpr* const lhsp = nodep->lhsp();
const int width = lhsp->dtypep()->width();
const size_t expected = std::is_same<T_Oper, AstXor>::value ? 0x1 << width : width + 1;
if (checkMaxExprs(expected)) return;
AstNodeExpr* unrolledp = new AstSel{fl, lhsp->cloneTree(false),
new AstConst{fl, static_cast<uint32_t>(width - 1)},
new AstConst{fl, 1}};
for (int bit = width - 2; bit >= 0; bit--) {
AstSel* const selp = new AstSel{fl, lhsp->cloneTree(false),
new AstConst{fl, static_cast<uint32_t>(bit)},
new AstConst{fl, 1}};
unrolledp = new T_Oper{fl, selp, unrolledp};
}
iterate(unrolledp);
pushDeletep(unrolledp);
} else {
iterateChildren(nodep);
lineTrack(nodep);
}
}
void visit(AstRedOr* nodep) override { exprReduce<AstOr>(nodep); }
void visit(AstRedAnd* nodep) override { exprReduce<AstAnd>(nodep); }
void visit(AstRedXor* nodep) override { exprReduce<AstXor>(nodep); }
void visit(AstLogIf* nodep) override {
if (m_seeking == NONE) {
coverExprs(nodep);
} else if (m_objective) {
exprEither(nodep, true, false, true);
} else {
exprBoth(nodep, true, true, false);
}
lineTrack(nodep);
}
void visit(AstLogEq* nodep) override {
VL_RESTORER(m_objective);
if (m_seeking == NONE) {
coverExprs(nodep);
} else {
m_objective = !m_objective;
xorExpr(nodep);
lineTrack(nodep);
}
}
void visit(AstFuncRef* nodep) override {
if (nodep->taskp()->lifetime().isAutomatic()) {
visit(static_cast<AstNodeExpr*>(nodep));
} else {
exprUnsupported(nodep, "non-automatic function");
}
}
void visit(AstNodeExpr* nodep) override {
if (m_seeking != SEEKING) {
iterateChildren(nodep);
} else {
ExprCoverageEligibleVisitor elgibleVisitor(nodep);
if (elgibleVisitor.eligible()) {
std::stringstream emitV;
V3EmitV::verilogForTree(nodep, emitV);
// Add new expression with a single term
CoverExpr expr;
expr.emplace_back(nodep, m_objective, emitV.str());
m_exprs.push_back(std::move(expr));
checkMaxExprs();
} else {
exprUnsupported(nodep, "not coverage eligible");
}
}
lineTrack(nodep);
}
// VISITORS - BOTH
void visit(AstNode* nodep) override {
iterateChildren(nodep);
lineTrack(nodep);
}
void exprUnsupported(AstNode* nodep, const string& why) {
UINFO(9, "unsupported: " << why << " " << nodep);
bool wasSeeking = m_seeking == SEEKING;
Objective oldSeeking = m_seeking;
if (wasSeeking) abortExprCoverage();
m_seeking = ABORTED;
iterateChildren(nodep);
lineTrack(nodep);
if (!wasSeeking) m_seeking = oldSeeking;
}
public:
// CONSTRUCTORS
explicit CoverageVisitor(AstNetlist* rootp) { iterateChildren(rootp); }
~CoverageVisitor() override = default;
};
//######################################################################
// Coverage class functions
void V3Coverage::coverage(AstNetlist* rootp) {
UINFO(2, __FUNCTION__ << ":");
{ CoverageVisitor{rootp}; } // Destruct before checking
V3Global::dumpCheckGlobalTree("coverage", 0, dumpTreeEitherLevel() >= 3);
}