Support bounded queues.

Changes

@@ -4,7 +4,7 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 * Verilator 4.025 devel
 
-***   Add BOUNDED warning and promote bounded queues to unbounded.
+***   Support bounded queues.
 
 ***   Support string compare, icompare, ato* methods, bug1606. [Yutetsu TAKATSUKASA]
 

include/verilated_heavy.h

@@ -185,7 +185,8 @@ std::string VL_TO_STRING(const VlAssocArray<T_Key, T_Value>& obj) {
 // There are no multithreaded locks on this; the base variable must
 // be protected by other means
 //
-template <class T_Value> class VlQueue {
+// Bound here is the maximum size() allowed, e.g. 1 + SystemVerilog bound
+template <class T_Value, size_t T_MaxSize = 0> class VlQueue {
 private:
     // TYPES
     typedef std::deque<T_Value> Deque;
@@ -215,9 +216,14 @@ public:
     void erase(size_t index) { if (VL_LIKELY(index < m_deque.size())) m_deque.erase(index); }
 
     // function void q.push_front(value)
-    void push_front(const T_Value& value) { m_deque.push_front(value); }
+    void push_front(const T_Value& value) {
+        m_deque.push_front(value);
+        if (VL_UNLIKELY(T_MaxSize != 0 && m_deque.size() > T_MaxSize)) m_deque.pop_back();
+    }
     // function void q.push_back(value)
-    void push_back(const T_Value& value) { m_deque.push_back(value); }
+    void push_back(const T_Value& value) {
+        if (VL_LIKELY(T_MaxSize == 0 || m_deque.size() < T_MaxSize)) m_deque.push_back(value);
+    }
     // function value_t q.pop_front();
     T_Value pop_front() {
         if (m_deque.empty()) return m_defaultValue;

src/V3AstNodes.cpp

@@ -285,6 +285,8 @@ AstVar::VlArgTypeRecursed AstVar::vlArgTypeRecurse(bool forFunc, const AstNodeDT
         if (!sub.m_osuffix.empty() || !sub.m_oref.empty()) {
             out += " " + sub.m_osuffix + sub.m_oref;
         }
+        // + 1 below as VlQueue uses 0 to mean unlimited, 1 to mean size() max is 1
+        if (adtypep->boundp()) out += ", " + cvtToStr(adtypep->boundConst() + 1);
         out += "> ";
         info.m_oprefix = out;
         return info;

src/V3AstNodes.h

@@ -743,8 +743,9 @@ class AstQueueDType : public AstNodeDType {
 private:
     AstNodeDType* m_refDTypep;  // Elements of this type (after widthing)
 public:
-    AstQueueDType(FileLine* fl, VFlagChildDType, AstNodeDType* dtp)
+    AstQueueDType(FileLine* fl, VFlagChildDType, AstNodeDType* dtp, AstNode* boundp)
         : AstNodeDType(fl) {
+        setNOp2p(boundp);
         childDTypep(dtp);  // Only for parser
         refDTypep(NULL);
         dtypep(NULL);  // V3Width will resolve
@@ -770,6 +771,9 @@ public:
     void childDTypep(AstNodeDType* nodep) { setOp1p(nodep); }
     virtual AstNodeDType* subDTypep() const { return m_refDTypep ? m_refDTypep : childDTypep(); }
     void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
+    AstNode* boundp() const { return op2p(); }  // op2 = Bound, NULL = none
+    void boundp(AstNode* nodep) { setNOp2p(nodep); }
+    int boundConst() const { AstConst* constp = VN_CAST(boundp(), Const); return (constp?constp->toSInt() : 0); }
     virtual AstNodeDType* virtRefDTypep() const { return m_refDTypep; }
     virtual void virtRefDTypep(AstNodeDType* nodep) { refDTypep(nodep); }
     // METHODS

src/V3Error.h

@@ -105,7 +105,6 @@ public:
         SYMRSVDWORD,    // Symbol is Reserved Word
         SYNCASYNCNET,   // Mixed sync + async reset
         TICKCOUNT,      // Too large tick count
-        UNBOUNDED,      // Unbounded queue
         UNDRIVEN,       // No drivers
         UNOPT,          // Unoptimizable block
         UNOPTFLAT,      // Unoptimizable block after flattening
@@ -155,7 +154,7 @@ public:
             "REALCVT", "REDEFMACRO",
             "SELRANGE", "SHORTREAL", "STMTDLY", "SYMRSVDWORD", "SYNCASYNCNET",
             "TICKCOUNT",
-            "UNBOUNDED", "UNDRIVEN", "UNOPT", "UNOPTFLAT", "UNOPTTHREADS",
+            "UNDRIVEN", "UNOPT", "UNOPTFLAT", "UNOPTTHREADS",
             "UNPACKED", "UNSIGNED", "UNUSED",
             "USERERROR", "USERFATAL", "USERINFO", "USERWARN",
             "VARHIDDEN", "WIDTH", "WIDTHCONCAT",

src/V3ParseGrammar.cpp

@@ -118,14 +118,11 @@ AstNodeDType* V3ParseGrammar::createArray(AstNodeDType* basep,
                     (rangep->fileline(), VFlagChildDType(), arrayp, rangep);
             } else if (VN_IS(nrangep, QueueRange)) {
                 arrayp = new AstQueueDType
-                    (nrangep->fileline(), VFlagChildDType(), arrayp);
+                    (nrangep->fileline(), VFlagChildDType(), arrayp, NULL);
             } else if (rangep && (VN_IS(rangep->leftp(), Unbounded)
                                   || VN_IS(rangep->rightp(), Unbounded))) {
-                if (!VN_IS(rangep->rightp(), Unbounded)) {
-                    rangep->v3warn(UNBOUNDED,
-                                   "Unsupported: Bounded queues. Converting to unbounded.");
-                }
-                arrayp = new AstQueueDType(nrangep->fileline(), VFlagChildDType(), arrayp);
+                arrayp = new AstQueueDType(nrangep->fileline(), VFlagChildDType(), arrayp,
+                                           rangep->rightp()->cloneTree(true));
             } else if (rangep) {
                 arrayp = new AstUnpackArrayDType
                     (rangep->fileline(), VFlagChildDType(), arrayp, rangep);

src/V3Width.cpp

@@ -1124,6 +1124,9 @@ private:
         // Iterate into subDTypep() to resolve that type and update pointer.
         nodep->refDTypep(iterateEditDTypep(nodep, nodep->subDTypep()));
         nodep->dtypep(nodep);  // The array itself, not subDtype
+        if (VN_IS(nodep->boundp(), Unbounded)) {
+            nodep->boundp()->unlinkFrBack()->deleteTree();  // NULL will represent unbounded
+        }
         UINFO(4,"dtWidthed "<<nodep<<endl);
     }
     virtual void visit(AstUnsizedArrayDType* nodep) {

test_regress/t/t_queue_bounded.v

@@ -5,17 +5,32 @@
 
 module t (/*AUTOARG*/);
 
-   // verilator lint_off UNBOUNDED
-   int q[$ : 3];
+   int q[$ : 2];  // Shall not go higher than [2], i.e. size 3
 
    initial begin
-      q.push_front(1);
-      q.push_front(1);
+      q.push_front(3);
+      if (q.size() != 1) $stop;
+      q.push_front(2);
+      if (q.size() != 2) $stop;
       q.push_front(1);
       if (q.size() != 3) $stop;
-      q.push_front(1);
-      // TODO correct answer when supported:
-      //if (q.size() != 3) $stop;
+      q.push_front(0);
+      if (q.size() != 3) $stop;
+      if (q[0] != 0) $stop;
+      if (q[1] != 1) $stop;
+      if (q[2] != 2) $stop;
+
+      q.delete();
+      q.push_back(0);
+      q.push_back(1);
+      q.push_back(2);
+      if (q.size() != 3) $stop;
+      q.push_back(3);
+      if (q.size() != 3) $stop;
+      if (q[0] != 0) $stop;
+      if (q[1] != 1) $stop;
+      if (q[2] != 2) $stop;
+
       $write("*-* All Finished *-*\n");
       $finish;
    end

test_regress/t/t_queue_bounded_unsup_bad.out

@@ -1,5 +0,0 @@
-%Warning-UNBOUNDED: t/t_queue_bounded_unsup_bad.v:7: Unsupported: Bounded queues. Converting to unbounded.
-   int q[$ : 3];
-        ^
-                    ... Use "/* verilator lint_off UNBOUNDED */" and lint_on around source to disable this message.
-%Error: Exiting due to

test_regress/t/t_queue_bounded_unsup_bad.pl

@@ -1,18 +0,0 @@
-#!/usr/bin/perl
-if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
-# DESCRIPTION: Verilator: Verilog Test driver/expect definition
-#
-# Copyright 2003 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.
-
-scenarios(linter => 1);
-
-lint(
-    fails => 1,
-    expect_filename => $Self->{golden_filename},
-    );
-
-ok(1);
-1;

test_regress/t/t_queue_bounded_unsup_bad.v

@@ -1,8 +0,0 @@
-// DESCRIPTION: Verilator: Verilog Test module
-//
-// This file ONLY is placed into the Public Domain, for any use,
-// without warranty, 2019 by Wilson Snyder.
-
-module t (/*AUTOARG*/);
-   int q[$ : 3];
-endmodule