verilator/src/V3Begin.cpp
2021-01-01 10:29:54 -05:00

301 lines
11 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Removal of named begin blocks
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2003-2021 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
//
//*************************************************************************
// V3Begin's Transformations:
//
// Each module:
// Look for BEGINs
// BEGIN(VAR...) -> VAR ... {renamed}
// FOR -> WHILEs
//
// There are two scopes; named BEGINs change %m and variable scopes.
// Unnamed BEGINs change only variable, not $display("%m") scope.
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include "V3Global.h"
#include "V3Begin.h"
#include "V3Ast.h"
#include <algorithm>
//######################################################################
class BeginState final {
private:
// NODE STATE
// Entire netlist:
// AstNodeFTask::user1 -> bool, 1=processed
AstUser1InUse m_inuser1;
bool m_anyFuncInBegin = false;
public:
BeginState() = default;
~BeginState() = default;
void userMarkChanged(AstNode* nodep) {
nodep->user1(true);
m_anyFuncInBegin = true;
}
bool anyFuncInBegin() const { return m_anyFuncInBegin; }
};
//######################################################################
class BeginVisitor final : public AstNVisitor {
private:
// STATE
BeginState* m_statep; // Current global state
AstNodeModule* m_modp = nullptr; // Current module
AstNodeFTask* m_ftaskp = nullptr; // Current function/task
string m_namedScope; // Name of begin blocks above us
string m_unnamedScope; // Name of begin blocks, including unnamed blocks
int m_ifDepth = 0; // Current if depth
// METHODS
VL_DEBUG_FUNC; // Declare debug()
string dot(const string& a, const string& b) {
if (a == "") return b;
return a + "__DOT__" + b;
}
// VISITORS
virtual void visit(AstNodeModule* nodep) override {
VL_RESTORER(m_modp);
{
m_modp = nodep;
iterateChildren(nodep);
}
}
virtual void visit(AstNodeFTask* nodep) override {
UINFO(8, " " << nodep << endl);
// Rename it
if (m_unnamedScope != "") {
nodep->name(dot(m_unnamedScope, nodep->name()));
UINFO(8, " rename to " << nodep->name() << endl);
m_statep->userMarkChanged(nodep);
}
// BEGIN wrapping a function rename that function, but don't affect
// the inside function's variables. We then restart with empty
// naming; so that any begin's inside the function will rename
// inside the function.
// Process children
VL_RESTORER(m_namedScope);
VL_RESTORER(m_unnamedScope);
{
m_namedScope = "";
m_unnamedScope = "";
m_ftaskp = nodep;
iterateChildren(nodep);
m_ftaskp = nullptr;
}
}
virtual void visit(AstBegin* nodep) override {
// Begin blocks were only useful in variable creation, change names and delete
UINFO(8, " " << nodep << endl);
VL_RESTORER(m_namedScope);
VL_RESTORER(m_unnamedScope);
{
UINFO(8, "nname " << m_namedScope << endl);
if (nodep->name() != "") { // Else unneeded unnamed block
// Create data for dotted variable resolution
string dottedname = nodep->name() + "__DOT__"; // So always found
string::size_type pos;
while ((pos = dottedname.find("__DOT__")) != string::npos) {
string ident = dottedname.substr(0, pos);
dottedname = dottedname.substr(pos + strlen("__DOT__"));
if (nodep->name() != "") m_namedScope = dot(m_namedScope, ident);
m_unnamedScope = dot(m_unnamedScope, ident);
// Create CellInline for dotted var resolution
if (!m_ftaskp) {
AstCellInline* inlinep = new AstCellInline(
nodep->fileline(), m_unnamedScope, "__BEGIN__", m_modp->timeunit());
m_modp->addInlinesp(inlinep); // Must be parsed before any AstCells
}
}
}
// Remap var names and replace lower Begins
iterateAndNextNull(nodep->stmtsp());
UASSERT_OBJ(!nodep->genforp(), nodep, "GENFORs should have been expanded earlier");
// Cleanup
AstNode* addsp = nullptr;
if (AstNode* stmtsp = nodep->stmtsp()) {
stmtsp->unlinkFrBackWithNext();
if (addsp) {
addsp = addsp->addNextNull(stmtsp);
} else {
addsp = stmtsp;
}
}
if (addsp) {
nodep->replaceWith(addsp);
} else {
nodep->unlinkFrBack();
}
VL_DO_DANGLING(pushDeletep(nodep), nodep);
}
}
virtual void visit(AstVar* nodep) override {
if (m_unnamedScope != "") {
// Rename it
nodep->name(dot(m_unnamedScope, nodep->name()));
m_statep->userMarkChanged(nodep);
// Move to module
nodep->unlinkFrBack();
if (m_ftaskp) {
m_ftaskp->addStmtsp(nodep); // Begins under funcs just move into the func
} else {
m_modp->addStmtp(nodep);
}
}
}
virtual void visit(AstTypedef* nodep) override {
if (m_unnamedScope != "") {
// Rename it
nodep->name(dot(m_unnamedScope, nodep->name()));
m_statep->userMarkChanged(nodep);
// Move to module
nodep->unlinkFrBack();
// Begins under funcs just move into the func
if (m_ftaskp) {
m_ftaskp->addStmtsp(nodep);
} else {
m_modp->addStmtp(nodep);
}
}
}
virtual void visit(AstCell* nodep) override {
UINFO(8, " CELL " << nodep << endl);
if (m_namedScope != "") {
m_statep->userMarkChanged(nodep);
// Rename it
nodep->name(dot(m_namedScope, nodep->name()));
UINFO(8, " rename to " << nodep->name() << endl);
// Move to module
nodep->unlinkFrBack();
m_modp->addStmtp(nodep);
}
iterateChildren(nodep);
}
virtual void visit(AstVarXRef* nodep) override {
UINFO(9, " VARXREF " << nodep << endl);
if (m_namedScope != "" && nodep->inlinedDots() == "" && !m_ftaskp) {
nodep->inlinedDots(m_namedScope);
UINFO(9, " rescope to " << nodep << endl);
}
}
virtual void visit(AstScopeName* nodep) override {
// If there's a %m in the display text, we add a special node that will contain the name()
// Similar code in V3Inline
if (nodep->user1SetOnce()) return; // Don't double-add text's
if (m_namedScope != "") {
// To keep correct visual order, must add before other Text's
AstNode* afterp = nodep->scopeAttrp();
if (afterp) afterp->unlinkFrBackWithNext();
nodep->scopeAttrp(new AstText(nodep->fileline(), string("__DOT__") + m_namedScope));
if (afterp) nodep->scopeAttrp(afterp);
}
iterateChildren(nodep);
}
virtual void visit(AstCoverDecl* nodep) override {
// Don't need to fix path in coverage statements, they're not under
// any BEGINs, but V3Coverage adds them all under the module itself.
iterateChildren(nodep);
}
// VISITORS - LINT CHECK
virtual void visit(AstIf* nodep) override { // not AstNodeIf; other types not covered
// Check IFDEPTH warning - could be in other transform files if desire
VL_RESTORER(m_ifDepth);
if (m_ifDepth == -1 || v3Global.opt.ifDepth() < 1) { // Turned off
} else if (nodep->uniquePragma() || nodep->unique0Pragma() || nodep->priorityPragma()) {
m_ifDepth = -1;
} else if (++m_ifDepth > v3Global.opt.ifDepth()) {
nodep->v3warn(IFDEPTH,
"Deep 'if' statement; suggest unique/priority to avoid slow logic");
nodep->fileline()->modifyWarnOff(V3ErrorCode::IFDEPTH, true); // Warn only once
m_ifDepth = -1;
}
iterateChildren(nodep);
}
virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
public:
// CONSTRUCTORS
BeginVisitor(AstNetlist* nodep, BeginState* statep)
: m_statep{statep} {
iterate(nodep);
}
virtual ~BeginVisitor() override = default;
};
//######################################################################
class BeginRelinkVisitor final : public AstNVisitor {
// Replace tasks with new pointer
private:
// NODE STATE
// Input:
// AstNodeFTask::user1p // Node replaced, rename it
// VISITORS
virtual void visit(AstNodeFTaskRef* nodep) override {
if (nodep->taskp()->user1()) { // It was converted
UINFO(9, " relinkFTask " << nodep << endl);
nodep->name(nodep->taskp()->name());
}
iterateChildren(nodep);
}
virtual void visit(AstVarRef* nodep) override {
if (nodep->varp()->user1()) { // It was converted
UINFO(9, " relinVarRef " << nodep << endl);
nodep->name(nodep->varp()->name());
}
iterateChildren(nodep);
}
virtual void visit(AstIfaceRefDType* nodep) override {
// May have changed cell names
// TypeTable is always after all modules, so names are stable
UINFO(8, " IFACEREFDTYPE " << nodep << endl);
if (nodep->cellp()) nodep->cellName(nodep->cellp()->name());
UINFO(8, " rename to " << nodep << endl);
iterateChildren(nodep);
}
//--------------------
virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
public:
// CONSTRUCTORS
BeginRelinkVisitor(AstNetlist* nodep, BeginState*) { iterate(nodep); }
virtual ~BeginRelinkVisitor() override = default;
};
//######################################################################
// Task class functions
void V3Begin::debeginAll(AstNetlist* nodep) {
UINFO(2, __FUNCTION__ << ": " << endl);
{
BeginState state;
{ BeginVisitor bvisitor(nodep, &state); }
if (state.anyFuncInBegin()) { BeginRelinkVisitor brvisitor(nodep, &state); }
} // Destruct before checking
V3Global::dumpCheckGlobalTree("begin", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
}