Add --public-flat-rw switch, bug1511.

This switch exposes VARs, PORTs and WIREs to C++ code. It must be use
with care as it has a significant performance impact and may result in
mis-simulation of generated clocks. Anyhow, it is prefered over
--public and useful for VPI.

Signed-off-by: Lukasz Dalek <ldalek@antmicro.com>
Signed-off-by: Stefan Wallentowitz <stefan@wallentowitz.de>
Signed-off-by: Wilson Snyder <wsnyder@wsnyder.org>

Changes

@@ -6,6 +6,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ***   Support $fseek, $ftell, $frewind, bug1496. [Howard Su]
 
+***   Add --public-flat-rw, bug1511. [Stefan Wallentowitz]
+
 ****  Fix make test with no VERILATOR_ROOT, bug1494. [Ahmed El-Mahmoudy]
 
 ****  Make Syms file honor --output-split-cfuncs, bug1499. [Todd Strader]

bin/verilator

@@ -354,6 +354,7 @@ detailed descriptions in L</"VERILATION ARGUMENTS"> for more information.
     --prof-threads              Enable generating gantt chart data for threads
     --private                   Debugging; see docs
     --public                    Debugging; see docs
+    --public-flat-rw            Mark all variables, etc as public_flat_rw
      -pvalue+<name>=<value>     Overwrite toplevel parameter
     --quiet-exit                Don't print the command on failure
     --relative-includes         Resolve includes relative to current file
@@ -1168,6 +1169,16 @@ inlining.  This will also turn off inlining as if all modules had a
 /*verilator public_module*/, unless the module specifically enabled it with
 /*verilator inline_module*/.
 
+=item --public-flat-rw
+
+Declares all variables, ports and wires public as if they had /*verilator
+public_flat_rw*/ comments.  This will make them VPI accessible by their
+flat name, but not turn off module inlining.  This is particularly useful
+in combination with --vpi. This may also in some rare cases result in
+mis-simulation of generated clocks.  Instead of this global switch, marking
+only those signals that need public_flat_rw is typically significantly
+better performing.
+
 =item -pvalue+I<name>=I<value>
 
 Overwrites the given parameter(s) of the toplevel module. See -G for a
@@ -2916,7 +2927,8 @@ signal should be declared public_flat (see above), but read-only.
 Used after an input, output, register, or wire declaration to indicate the
 signal should be declared public_flat_rd (see above), and also writable,
 where writes should be considered to have the timing specified by the given
-sensitivity edge list.
+sensitivity edge list.  Set for all variables, ports and wires using the
+--public-flat-rw switch.
 
 =item /*verilator public_module*/
 

docs/CONTRIBUTORS

@@ -10,6 +10,7 @@ Howard Su
 Jeremy Bennett
 John Coiner
 Kanad Kanhere
+Lukasz Dalek
 Maarten De Braekeleer
 Philipp Wagner
 Richard Myers

src/V3LinkParse.cpp

@@ -189,6 +189,17 @@ private:
             return;
         }
 
+        if (v3Global.opt.publicFlatRW()) {
+            switch (nodep->varType()) {
+            case AstVarType::VAR:
+            case AstVarType::PORT:
+            case AstVarType::WIRE:
+                nodep->sigUserRWPublic(true);
+                break;
+            default: break;
+            }
+        }
+
         // We used modTrace before leveling, and we may now
         // want to turn it off now that we know the levelizations
         if (v3Global.opt.traceDepth()
@@ -198,6 +209,7 @@ private:
             nodep->trace(false);
         }
         m_varp = nodep;
+
         iterateChildren(nodep);
         m_varp = NULL;
         // temporaries under an always aren't expected to be blocking

src/V3Options.cpp

@@ -696,6 +696,7 @@ void V3Options::parseOptsList(FileLine* fl, const string& optdir, int argc, char
             else if ( onoff (sw, "-profile-cfuncs", flag/*ref*/))    { m_profCFuncs = flag; }  // Undocumented, for backward compat
             else if ( onoff (sw, "-prof-threads", flag/*ref*/))      { m_profThreads = flag; }
             else if ( onoff (sw, "-public", flag/*ref*/))            { m_public = flag; }
+            else if ( onoff (sw, "-public-flat-rw", flag/*ref*/) )   { m_publicFlatRW = flag; v3Global.dpi(true); }
             else if (!strncmp(sw, "-pvalue+", strlen("-pvalue+")))     { addParameter(string(sw+strlen("-pvalue+")), false); }
             else if ( onoff (sw, "-relative-cfuncs", flag/*ref*/))   { m_relativeCFuncs = flag; }
             else if ( onoff (sw, "-relative-includes", flag/*ref*/)) { m_relativeIncludes = flag; }
@@ -1297,6 +1298,7 @@ V3Options::V3Options() {
     m_preprocOnly = false;
     m_preprocNoLine = false;
     m_public = false;
+    m_publicFlatRW = false;
     m_relativeCFuncs = true;
     m_relativeIncludes = false;
     m_reportUnoptflat = false;

src/V3Options.h

@@ -135,6 +135,7 @@ class V3Options {
     bool        m_profCFuncs;   // main switch: --prof-cfuncs
     bool        m_profThreads;  // main switch: --prof-threads
     bool        m_public;       // main switch: --public
+    bool        m_publicFlatRW;  // main switch: --public-flat-rw
     bool        m_relativeCFuncs; // main switch: --relative-cfuncs
     bool        m_relativeIncludes; // main switch: --relative-includes
     bool        m_reportUnoptflat; // main switch: --report-unoptflat
@@ -309,6 +310,7 @@ class V3Options {
     bool profCFuncs() const { return m_profCFuncs; }
     bool profThreads() const { return m_profThreads; }
     bool allPublic() const { return m_public; }
+    bool publicFlatRW() const { return m_publicFlatRW; }
     bool lintOnly() const { return m_lintOnly; }
     bool ignc() const { return m_ignc; }
     bool inhibitSim() const { return m_inhibitSim; }

test_regress/t/t_vpi_get.cpp

@@ -246,7 +246,7 @@ int main(int argc, char **argv, char **env) {
     Verilated::commandArgs(argc, argv);
     Verilated::debug(0);
 
-    VM_PREFIX* topp = new VM_PREFIX("");  // Note null name - we're flattening it out
+    Vt_vpi_get* topp = new Vt_vpi_get("");  // Note null name - we're flattening it out
 
 #ifdef VERILATOR
 # ifdef TEST_VERBOSE

test_regress/t/t_vpi_get.pl

@@ -18,7 +18,7 @@ compile(
     verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_get.cpp"],
     make_pli => 1,
     iv_flags2 => ["-g2005-sv -D USE_VPI_NOT_DPI"],
-    v_flags2 => ["+define+USE_VPI_NOT_DPI"],
+    v_flags2 => ["+define+USE_VPI_NOT_DPI +define+VERILATOR_COMMENTS"],
 );
 
 execute(

test_regress/t/t_vpi_get.v

@@ -11,13 +11,21 @@
 import "DPI-C" context function integer mon_check();
 `endif
 
+`ifdef VERILATOR_COMMENTS
+ `define PUBLIC_FLAT_RD /*verilator public_flat_rd*/
+ `define PUBLIC_FLAT_RW /*verilator public_flat_rw @(posedge clk)*/
+`else
+ `define PUBLIC_FLAT_RD
+ `define PUBLIC_FLAT_RW
+`endif
+
 module t (/*AUTOARG*/
    // Inputs
-   input clk                          	/*verilator public_flat_rd		  */,
+   input clk                            `PUBLIC_FLAT_RD,
 
    // test ports
-   input  [15:0] 	testin  	/*verilator public_flat_rd		  */,
-   output [23:0] 	testout 	/*verilator public_flat_rw @(posedge clk) */
+   input  [15:0]        testin          `PUBLIC_FLAT_RD,
+   output [23:0]        testout     `PUBLIC_FLAT_RW
 
    );
 
@@ -27,10 +35,10 @@ extern "C" int mon_check();
 `verilog
 `endif
 
-   reg		onebit		/*verilator public_flat_rw @(posedge clk) */;
-   reg [2:1]	twoone		/*verilator public_flat_rw @(posedge clk) */;
-   reg   	onetwo [1:2]	/*verilator public_flat_rw @(posedge clk) */;
-   reg [2:1] 	fourthreetwoone[4:3] /*verilator public_flat_rw @(posedge clk) */;
+   reg          onebit          `PUBLIC_FLAT_RW;
+   reg [2:1]    twoone          `PUBLIC_FLAT_RW;
+   reg          onetwo [1:2]    `PUBLIC_FLAT_RW;
+   reg [2:1]    fourthreetwoone[4:3] `PUBLIC_FLAT_RW;
 
    integer      status;
 
@@ -39,8 +47,8 @@ extern "C" int mon_check();
    wire 	redundant = onebit | onetwo[1] | twoone | fourthreetwoone[3];
 `endif
 
-   wire         subin  /*verilator public_flat_rd*/;
-   wire         subout /*verilator public_flat_rd*/;
+   wire         subin  `PUBLIC_FLAT_RD;
+   wire         subout `PUBLIC_FLAT_RD;
    sub sub(.*);
 
    // Test loop
@@ -65,7 +73,7 @@ extern "C" int mon_check();
 endmodule : t
 
 module sub (
-   input  subin  /*verilator public_flat_rd*/,
-   output subout /*verilator public_flat_rd*/
+   input  subin  `PUBLIC_FLAT_RD,
+   output subout `PUBLIC_FLAT_RD
 );
 endmodule : sub

test_regress/t/t_vpi_get_public_rw_switch.pl

@@ -0,0 +1,36 @@
+#!/usr/bin/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.
+
+scenarios(simulator => 1);
+
+skip("Known compiler limitation")
+    if $Self->cxx_version =~ /\(GCC\) 4.4/;
+
+VM_PREFIX("Vt_vpi_get");
+top_filename("t/t_vpi_get.v");
+pli_filename("t_vpi_get.cpp");
+
+compile(
+    make_top_shell => 0,
+    make_main => 0,
+    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi"
+                         ." --public-flat-rw --prefix Vt_vpi_get --no-l2name"
+                         ." $Self->{t_dir}/t_vpi_get.cpp"],
+    make_pli => 1,
+    iv_flags2 => ["-g2005-sv -D USE_VPI_NOT_DPI"],
+    v_flags2 => ["+define+USE_VPI_NOT_DPI"],
+);
+
+execute(
+    iv_pli => 1,
+    check_finished => 1
+);
+
+ok(1);
+1;