Fix VPI upper interface scopes not found (#3937).

Changes

@@ -25,6 +25,7 @@ Verilator 5.007 devel
 * Fix pattern assignment to unpacked structs (#3510). [Mostafa Garnal]
 * Fix single-element replication to dynarray/unpacked/queue (#3548). [Gustav Svensk]
 * Fix very long VPI signal names (#3929). [Marlon James]
+* Fix VPI upper interface scopes not found (#3937). [David Stanford]
 
 
 Verilator 5.006 2023-01-22

src/V3EmitCSyms.cpp

@@ -186,7 +186,7 @@ class EmitCSyms final : EmitCBaseVisitor {
 
     void varHierarchyScopes(string scp) {
         while (!scp.empty()) {
-            const auto scpit = m_vpiScopeCandidates.find(scp);
+            const auto scpit = m_vpiScopeCandidates.find(scopeSymString(scp));
             if ((scpit != m_vpiScopeCandidates.end())
                 && (m_scopeNames.find(scp) == m_scopeNames.end())) {
                 const auto scopeNameit = m_scopeNames.find(scpit->second.m_symName);
@@ -314,8 +314,9 @@ class EmitCSyms final : EmitCBaseVisitor {
             const string name = nodep->scopep()->shortName() + "__DOT__" + nodep->name();
             const string name_pretty = AstNode::vpiName(name);
             const int timeunit = m_modp->timeunit().powerOfTen();
-            m_vpiScopeCandidates.insert(std::make_pair(
+            m_vpiScopeCandidates.insert(
-                name, ScopeData{scopeSymString(name), name_pretty, timeunit, type}));
+                std::make_pair(scopeSymString(name),
+                               ScopeData{scopeSymString(name), name_pretty, timeunit, type}));
         }
     }
     void visit(AstScope* nodep) override {
@@ -328,15 +329,15 @@ class EmitCSyms final : EmitCBaseVisitor {
             const string type = VN_IS(nodep->modp(), Package) ? "SCOPE_OTHER" : "SCOPE_MODULE";
             const string name_pretty = AstNode::vpiName(nodep->shortName());
             const int timeunit = m_modp->timeunit().powerOfTen();
-            m_vpiScopeCandidates.insert(
+            m_vpiScopeCandidates.insert(std::make_pair(
-                std::make_pair(nodep->name(), ScopeData{scopeSymString(nodep->name()), name_pretty,
+                scopeSymString(nodep->name()),
-                                                        timeunit, type}));
+                ScopeData{scopeSymString(nodep->name()), name_pretty, timeunit, type}));
         }
     }
     void visit(AstScopeName* nodep) override {
         const string name = nodep->scopeSymName();
-        // UINFO(9,"scnameins sp "<<nodep->name()<<" sp "<<nodep->scopePrettySymName()
+        // UINFO(9, "scnameins sp " << nodep->name() << " sp " << nodep->scopePrettySymName()
-        // <<" ss"<<name<<endl);
+        // << " ss" << name << endl);
         const int timeunit = m_modp ? m_modp->timeunit().powerOfTen() : 0;
         m_scopeNames.emplace(
             name, ScopeData{name, nodep->scopePrettySymName(), timeunit, "SCOPE_OTHER"});

test_regress/t/t_vpi_module_empty.cpp

@@ -0,0 +1,123 @@
+// -*- mode: C++; c-file-style: "cc-mode" -*-
+//*************************************************************************
+//
+// Copyright 2010-2023 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
+//
+//*************************************************************************
+
+#ifdef IS_VPI
+
+#include "vpi_user.h"
+
+#include <cstdlib>
+
+#else
+
+#include "verilated.h"
+#include "verilated_vcd_c.h"
+#include "verilated_vpi.h"
+
+#include "Vt_vpi_module_empty.h"
+#include "Vt_vpi_module_empty__Dpi.h"
+#include "svdpi.h"
+
+#endif
+
+#include <cstdio>
+#include <cstring>
+#include <iostream>
+
+// These require the above. Comment prevents clang-format moving them
+#include "TestSimulator.h"
+#include "TestVpi.h"
+
+// __FILE__ is too long
+#define FILENM "t_vpi_module_empty.cpp"
+
+#define DEBUG \
+    if (0) printf
+
+#define CHECK_RESULT_NZ(got) \
+    if (!(got)) { \
+        printf("%%Error: %s:%d: GOT = NULL  EXP = !NULL\n", FILENM, __LINE__); \
+        return __LINE__; \
+    }
+
+extern "C" {
+int mon_check() {
+#ifdef TEST_VERBOSE
+    printf("-mon_check()\n");
+#endif
+
+    TestVpiHandle it = vpi_iterate(vpiModule, NULL);
+    CHECK_RESULT_NZ(it);
+    return 0;  // Ok
+}
+}
+//======================================================================
+
+#ifdef IS_VPI
+
+static int mon_check_vpi() {
+    TestVpiHandle href = vpi_handle(vpiSysTfCall, 0);
+    s_vpi_value vpi_value;
+
+    vpi_value.format = vpiIntVal;
+    vpi_value.value.integer = mon_check();
+    vpi_put_value(href, &vpi_value, NULL, vpiNoDelay);
+
+    return 0;
+}
+
+static s_vpi_systf_data vpi_systf_data[] = {{vpiSysFunc, vpiIntFunc, (PLI_BYTE8*)"$mon_check",
+                                             (PLI_INT32(*)(PLI_BYTE8*))mon_check_vpi, 0, 0, 0},
+                                            0};
+
+// cver entry
+void vpi_compat_bootstrap(void) {
+    p_vpi_systf_data systf_data_p;
+    systf_data_p = &(vpi_systf_data[0]);
+    while (systf_data_p->type != 0) vpi_register_systf(systf_data_p++);
+}
+
+// icarus entry
+void (*vlog_startup_routines[])() = {vpi_compat_bootstrap, 0};
+
+#else
+
+int main(int argc, char** argv) {
+    const std::unique_ptr<VerilatedContext> contextp{new VerilatedContext};
+
+    uint64_t sim_time = 1100;
+    contextp->debug(0);
+    contextp->commandArgs(argc, argv);
+    // we're going to be checking for these errors do don't crash out
+    contextp->fatalOnVpiError(0);
+
+    // Test second construction
+    const std::unique_ptr<VM_PREFIX> topp{new VM_PREFIX{contextp.get(),
+                                                        // Note null name - we're flattening it out
+                                                        ""}};
+
+#ifdef VERILATOR
+#ifdef TEST_VERBOSE
+    contextp->scopesDump();
+#endif
+#endif
+
+    topp->eval();
+    VerilatedVpi::callValueCbs();
+    TestVpiHandle vh = vpi_handle_by_name((PLI_BYTE8*)"top.sv_if_i.a", NULL);
+    CHECK_RESULT_NZ(vh);
+    TestVpiHandle it = vpi_iterate(vpiModule, NULL);
+    CHECK_RESULT_NZ(it);
+
+    topp->final();
+    return 0;
+}
+
+#endif

test_regress/t/t_vpi_module_empty.pl

@@ -0,0 +1,30 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2010 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
+
+scenarios(simulator => 1);
+
+skip("Known compiler limitation")
+    if $Self->cxx_version =~ /\(GCC\) 4.4/;
+
+compile(
+    make_top_shell => 0,
+    make_main => 0,
+    make_pli => 1,
+    iv_flags2 => ["-g2005-sv"],
+    verilator_flags2 => ["+define+USE_DOLLAR_C32 --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_module_empty.cpp"],
+    );
+
+execute(
+    use_libvpi => 1,
+    check_finished => 1
+    );
+
+ok(1);
+1;

test_regress/t/t_vpi_module_empty.v

@@ -0,0 +1,25 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// Copyright 2023 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
+
+interface sv_if();
+  logic a /*verilator public_flat_rw*/;
+endinterface
+
+module top ();
+
+   sv_if sv_if_i();
+
+   // Workaround for bug3937:
+   // logic d /*verilator public_flat_rw*/;
+
+   initial begin
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+
+endmodule