Add creating __inputs.vpp file with --debug (#4177).

Changes

@@ -19,6 +19,7 @@ Verilator 5.011 devel
 **Minor:**
 
 * Support get_randstate/set_randstate class method function.
+* Add creating __inputs.vpp file with --debug (#4177). [Tudor Timi]
 * Optimize VPI callValueCbs (#4155). [Hennadii Chernyshchyk]
 * Fix crash on duplicate imported modules (#3231). [Robert Balas]
 * Fix false WIDTHEXPAND on array declarations (#3959). [JOTEGO]

docs/guide/files.rst

@@ -126,8 +126,10 @@ In specific debug and other modes, it also creates:
      - Debugging graph files (from --debug)
    * - *{prefix}{misc}*\ .tree
      - Debugging files (from --debug)
-   * - {mod_prefix}_{each_verilog_base_filename}*\ .vpp
-     - Pre-processed verilog (from --debug)
+   * - *{prefix}*\ __inputs\ .vpp
+     - Pre-processed verilog for all files (from --debug)
+   * - *{prefix}*\ _ *{each_verilog_base_filename}*\ .vpp
+     - Pre-processed verilog for each file (from --debug)
 
 After running Make, the C++ compiler may produce the following:
 

docs/internals.rst

@@ -1503,8 +1503,19 @@ debug level 5, with the V3Width.cpp file at level 9.
 --debug
 -------
 
-When you run with ``--debug``, there are two primary output file types
-placed into the obj_dir, .tree and .dot files.
+When you run with ``--debug``, there are three primary output file types
+placed into the obj_dir, .vpp, .tree and .dot files.
+
+.vpp Output
+-----------
+
+Verilator creates a *{mod_prefix}*\ __inputs\ .vpp file containing all the
+files that were read, filtered by preprocessing. This file can be fed back
+into Verilator, replacing on the command line all of the previous input
+files, to enable simplification of test cases.
+
+Verilator also creates .vpp files for each individual file passed on the
+command line.
 
 
 .dot Output

src/V3ParseImp.cpp

@@ -35,6 +35,7 @@
 #include "V3Os.h"
 #include "V3ParseBison.h"  // Generated by bison
 #include "V3PreShell.h"
+#include "V3Stats.h"
 
 #include <sstream>
 
@@ -247,24 +248,22 @@ size_t V3ParseImp::ppInputToLex(char* buf, size_t max_size) {
     return got;
 }
 
-void V3ParseImp::preprocDumps(std::ostream& os) {
-    if (v3Global.opt.dumpDefines()) {
-        V3PreShell::dumpDefines(os);
-    } else {
-        const bool noblanks = v3Global.opt.preprocOnly() && v3Global.opt.preprocNoLine();
-        for (auto& buf : m_ppBuffers) {
-            if (noblanks) {
-                bool blank = true;
-                for (string::iterator its = buf.begin(); its != buf.end(); ++its) {
-                    if (!std::isspace(*its) && *its != '\n') {
-                        blank = false;
-                        break;
-                    }
+void V3ParseImp::preprocDumps(std::ostream& os, bool forInputs) {
+    bool noblanks = forInputs || (v3Global.opt.preprocOnly() && v3Global.opt.preprocNoLine());
+    bool nolines = forInputs;
+    for (auto& buf : m_ppBuffers) {
+        if (noblanks) {
+            bool blank = true;
+            for (string::iterator its = buf.begin(); its != buf.end(); ++its) {
+                if (!std::isspace(*its) && *its != '\n') {
+                    blank = false;
+                    break;
                 }
-                if (blank) continue;
             }
-            os << buf;
+            if (blank) continue;
+            if (nolines && buf.rfind("`line ", 0) == 0) continue;
         }
+        os << buf;
     }
 }
 
@@ -292,7 +291,7 @@ void V3ParseImp::parseFile(FileLine* fileline, const string& modfilename, bool i
     if (v3Global.opt.preprocOnly() || v3Global.opt.keepTempFiles()) {
         // Create output file with all the preprocessor output we buffered up
         const string vppfilename = v3Global.opt.hierTopDataDir() + "/" + v3Global.opt.prefix()
-                                   + "_" + nondirname + ".vpp";
+                                   + "__" + nondirname + ".vpp";
         std::ofstream* ofp = nullptr;
         std::ostream* osp;
         if (v3Global.opt.preprocOnly()) {
@@ -303,15 +302,20 @@ void V3ParseImp::parseFile(FileLine* fileline, const string& modfilename, bool i
         if (osp->fail()) {
             fileline->v3error("Cannot write preprocessor output: " + vppfilename);
             return;
+        }
+        if (v3Global.opt.dumpDefines()) {
+            V3PreShell::dumpDefines(*osp);
         } else {
-            preprocDumps(*osp);
-            if (ofp) {
-                ofp->close();
-                VL_DO_DANGLING(delete ofp, ofp);
-            }
+            preprocDumps(*osp, false);
+        }
+        if (ofp) {
+            ofp->close();
+            VL_DO_DANGLING(delete ofp, ofp);
         }
     }
 
+    if (debug() && modfilename != V3Options::getStdPackagePath()) dumpInputsFile();
+
     // Parse it
     if (!v3Global.opt.preprocOnly()) {
         lexFile(modfilename);
@@ -320,6 +324,31 @@ void V3ParseImp::parseFile(FileLine* fileline, const string& modfilename, bool i
     }
 }
 
+void V3ParseImp::dumpInputsFile() {
+    // Create output file with joined preprocessor output we buffered up,
+    // Useful for debug to feed back into Verilator
+    static bool append = false;
+    const string vppfilename
+        = v3Global.opt.hierTopDataDir() + "/" + v3Global.opt.prefix() + "__inputs.vpp";
+    std::ofstream* ofp = V3File::new_ofstream(vppfilename, append);
+    if (ofp->fail()) {
+        v3error("Cannot write preprocessor output: " + vppfilename);
+        return;
+    }
+    if (!append) {
+        append = true;
+        UINFO(1, "Writing all preprocessed output to " << vppfilename << endl);
+        *ofp << "// Dump of all post-preprocessor input\n";
+        *ofp << "// Blank lines and `line directives have been removed\n";
+        *ofp << "//\n";
+        V3Stats::infoHeader(*ofp, "// ");
+    }
+    *ofp << "\n";
+    preprocDumps(*ofp, true);
+    ofp->close();
+    VL_DO_DANGLING(delete ofp, ofp);
+}
+
 void V3ParseImp::lexFile(const string& modname) {
     // Prepare for lexing
     UINFO(3, "Lexing " << modname << endl);

src/V3ParseImp.h

@@ -295,6 +295,7 @@ public:
 
     void parseFile(FileLine* fileline, const string& modfilename, bool inLibrary,
                    const string& errmsg);
+    void dumpInputsFile();
 
 private:
     void lexFile(const string& modname);
@@ -305,7 +306,7 @@ private:
     size_t tokenPipeScanParam(size_t depth);
     size_t tokenPipeScanType(size_t depth);
     const V3ParseBisonYYSType* tokenPeekp(size_t depth);
-    void preprocDumps(std::ostream& os);
+    void preprocDumps(std::ostream& os, bool forInputs);
 };
 
 #endif  // Guard

src/V3Stats.h

@@ -121,6 +121,8 @@ public:
     static void statsFinalAll(AstNetlist* nodep);
     /// Called by the top level to dump the statistics
     static void statsReport();
+    /// Called by debug dumps
+    static void infoHeader(std::ofstream& os, const string& prefix);
 };
 
 #endif  // Guard

src/V3StatsReport.cpp

@@ -40,18 +40,8 @@ class StatsReport final {
     std::ofstream& os;  ///< Output stream
     static StatColl s_allStats;  ///< All statistics
 
-    void header() {
-        os << "Verilator Statistics Report\n\n";
-
-        os << "Information:\n";
-        os << "  " << V3Options::version() << '\n';
-        os << "  Arguments: " << v3Global.opt.allArgsString() << '\n';
-        os << "  Build jobs: " << v3Global.opt.buildJobs() << '\n';
-        os << "  Verilate jobs: " << v3Global.opt.verilateJobs() << '\n';
-        os << '\n';
-    }
-
     void sumit() {
+        os << '\n';
         // If sumit is set on a statistic, combine with others of same name
         std::multimap<std::string, V3Statistic*> byName;
         // * is always first
@@ -179,7 +169,8 @@ public:
     // CONSTRUCTORS
     explicit StatsReport(std::ofstream* aofp)
         : os(*aofp) {  // Need () or GCC 4.8 false warning
-        header();
+        os << "Verilator Statistics Report\n\n";
+        V3Stats::infoHeader(os, "");
         sumit();
         stars();
         stages();
@@ -222,6 +213,14 @@ void V3Stats::statsStage(const string& name) {
     V3Stats::addStatPerf("Stage, Memory (MB), " + digitName, memory);
 }
 
+void V3Stats::infoHeader(std::ofstream& os, const string& prefix) {
+    os << prefix << "Information:\n";
+    os << prefix << "  " << V3Options::version() << '\n';
+    os << prefix << "  Arguments: " << v3Global.opt.allArgsString() << '\n';
+    os << prefix << "  Build jobs: " << v3Global.opt.buildJobs() << '\n';
+    os << prefix << "  Verilate jobs: " << v3Global.opt.verilateJobs() << '\n';
+}
+
 void V3Stats::statsReport() {
     UINFO(2, __FUNCTION__ << ": " << endl);
 

test_regress/t/t_debug_inputs.pl

@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+scenarios(vlt => 1);
+
+lint(
+    v_flags => ["--debug --debugi 1 -Wno-MULTITOP t/t_debug_inputs_b.v"],
+    );
+
+file_grep("$Self->{obj_dir}/V$Self->{name}__inputs.vpp", qr/module t_debug_inputs /);
+file_grep("$Self->{obj_dir}/V$Self->{name}__inputs.vpp", qr/module t_debug_inputs_a /);
+file_grep("$Self->{obj_dir}/V$Self->{name}__inputs.vpp", qr/module t_debug_inputs_b /);
+
+ok(1);
+1;

test_regress/t/t_debug_inputs.v

@@ -0,0 +1,11 @@
+// DESCRIPTION: Verilator: Dotted reference that uses another dotted reference
+// as the select expression
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2023 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+`include "t/t_debug_inputs_a.v"
+
+module t_debug_inputs (/*AUTOARG*/);
+endmodule

test_regress/t/t_debug_inputs_a.v

@@ -0,0 +1,9 @@
+// DESCRIPTION: Verilator: Dotted reference that uses another dotted reference
+// as the select expression
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2023 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+module t_debug_inputs_a (/*AUTOARG*/);
+endmodule

test_regress/t/t_debug_inputs_b.v

@@ -0,0 +1,9 @@
+// DESCRIPTION: Verilator: Dotted reference that uses another dotted reference
+// as the select expression
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2023 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+module t_debug_inputs_b (/*AUTOARG*/);
+endmodule