Add --prof-c to pass profiling to compiler (#3059).

Changes

@@ -24,6 +24,7 @@ Verilator 4.205 devel
 
 **Minor:**
 
+* Add --prof-c to pass profiling to compiler (#3059). [Alexander Grobman]
 * Optimize a lot more model variables into function locals (#3027). [Geza Lore]
 * Support middle-of-design nested topmodules (#3026). [Dan Petrisko]
 * Remove deprecated --no-relative-cfuncs option (#3024). [Geza Lore]

bin/verilator

@@ -367,6 +367,7 @@ detailed descriptions of these arguments.
     --pipe-filter <command>     Filter all input through a script
     --pp-comments               Show preprocessor comments with -E
     --prefix <topname>          Name of top level class
+    --prof-c                    Compile C++ code with profiling
     --prof-cfuncs               Name functions for profiling
     --prof-threads              Enable generating gantt chart data for threads
     --protect-key <key>         Key for symbol protection

bin/verilator_profcfunc

@@ -202,7 +202,7 @@ verilator_profcfunc - Read gprof report created with --prof-cfuncs
 =head1 SYNOPSIS
 
   verilator --prof-cfuncs ....
-  gcc --ggdb -pg ....
+  gcc ....
   {run executable}
   gprof
   verilator_profcfuncs gprof.out

ci/ci-script.bash

@@ -69,6 +69,7 @@ elif [ "$CI_BUILD_STAGE_NAME" = "test" ]; then
 
   if [ "$CI_OS_NAME" = "osx" ]; then
     export VERILATOR_TEST_NO_GDB=1  # Pain to get GDB to work on OS X
+    # TODO below may no longer be requried as configure checks for -pg
     export VERILATOR_TEST_NO_GPROF=1  # Apple Clang has no -pg
     # export PATH="/Applications/gtkwave.app/Contents/Resources/bin:$PATH" # fst2vcd
     file bin/verilator_bin
@@ -84,6 +85,7 @@ elif [ "$CI_BUILD_STAGE_NAME" = "test" ]; then
     "$MAKE" -j "$NPROC" -k
   elif [ "$CI_OS_NAME" = "freebsd" ]; then
     export VERILATOR_TEST_NO_GDB=1 # Disable for now, ideally should run
+    # TODO below may no longer be requried as configure checks for -pg
     export VERILATOR_TEST_NO_GPROF=1 # gprof is a bit different on FreeBSD, disable
   fi
 

configure.ac

@@ -340,6 +340,10 @@ if test "$CFG_ENABLE_COVERAGE" = "yes"; then
   _MY_CXX_CHECK_OPT(CXX,-DVL_GCOV)
 fi
 
+# Compiler flags to enable profiling
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_PROFILE,-pg)
+AC_SUBST(CFG_CXXFLAGS_PROFILE)
+
 # Flag to select newest language standard supported
 # Macros work such that first option that passes is the one we take
 # Currently enabled gnu++14/c++14 due to packaged SystemC dependency

docs/guide/exe_verilator.rst

@@ -803,6 +803,13 @@ Summary:
    prepended to the name of the :vlopt:`--top` option, or V prepended to
    the first Verilog filename passed on the command line.
 
+.. option:: --prof-c
+
+   When compiling the C++ code, enable the compiler's profiling flag
+   (e.g. :code:`g++ -pg`). See :ref:`Profiling`.
+
+   Using :vlopt:`--prof-cfuncs` also enables :vlopt:`prof-c`.
+
 .. option:: --prof-cfuncs
 
    Modify the created C++ functions to support profiling.  The functions
@@ -813,6 +820,8 @@ Summary:
    came from.  This allows gprof or oprofile reports to be correlated with
    the original Verilog source statements. See :ref:`Profiling`.
 
+   Using :vlopt:`--prof-cfuncs` also enables :vlopt:`prof-c`.
+
 .. option:: --prof-threads
 
    Enable gantt chart data collection for threaded builds. See :ref:`Thread

docs/guide/simulating.rst

@@ -272,8 +272,6 @@ profiled C++ code functions.
 To use profiling:
 
 #. Use Verilator's :vlopt:`--prof-cfuncs`.
-#. Use Verilator's :vlopt:`-CFLAGS "-g -pg" <-CFLAGS>` to pass the
-   profiling flags through to GCC/Clang.
 #. Build and run the simulation model.
 #. The model will create gmon.out.
 #. Run :command:`gprof` to see where in the C++ code the time is spent.

include/verilated.mk.in

@@ -19,6 +19,8 @@ PYTHON3 = @PYTHON3@
 CFG_WITH_CCWARN = @CFG_WITH_CCWARN@
 CFG_WITH_LONGTESTS = @CFG_WITH_LONGTESTS@
 
+# Compiler flags to enable profiling
+CFG_CXXFLAGS_PROFILE = @CFG_CXXFLAGS_PROFILE@
 # Select newest language
 CFG_CXXFLAGS_STD_NEWEST = @CFG_CXXFLAGS_STD_NEWEST@
 # Select oldest language (for Verilator internal testing only)
@@ -103,6 +105,14 @@ OPT_FAST = -Os
 # to change this as the library is small, but can have significant speed impact.
 OPT_GLOBAL = -Os
 
+#######################################################################
+##### Profile builds
+
+ifeq ($(VM_PROFC),1)
+  CPPFLAGS += $(CFG_CXXFLAGS_PROFILE)
+  LDFLAGS  += $(CFG_CXXFLAGS_PROFILE)
+endif
+
 #######################################################################
 ##### SystemC builds
 

src/V3EmitMk.cpp

@@ -168,6 +168,8 @@ public:
         }
 
         of.puts("\n### Switches...\n");
+        of.puts("# C++ code coverage  0/1 (from --prof-c)\n");
+        of.puts(string("VM_PROFC = ") + ((v3Global.opt.profC()) ? "1" : "0") + "\n");
         of.puts("# SystemC output mode?  0/1 (from --sc)\n");
         of.puts(string("VM_SC = ") + ((v3Global.opt.systemC()) ? "1" : "0") + "\n");
         of.puts("# Legacy or SystemC output mode?  0/1 (from --sc)\n");

src/V3Options.cpp

@@ -1222,8 +1222,10 @@ void V3Options::parseOptsList(FileLine* fl, const string& optdir, int argc, char
         if (m_modPrefix == "") m_modPrefix = m_prefix;
     });
     DECL_OPTION("-private", CbCall, [this]() { m_public = false; });
-    DECL_OPTION("-prof-cfuncs", OnOff, &m_profCFuncs);
+    DECL_OPTION("-prof-c", OnOff, &m_profC);
-    DECL_OPTION("-profile-cfuncs", OnOff, &m_profCFuncs).undocumented();  // Renamed
+    DECL_OPTION("-prof-cfuncs", CbCall, [this]() { m_profC = m_profCFuncs = true; });
+    DECL_OPTION("-profile-cfuncs", CbCall,
+                [this]() { m_profC = m_profCFuncs = true; });  // Renamed
     DECL_OPTION("-prof-threads", OnOff, &m_profThreads);
     DECL_OPTION("-protect-ids", OnOff, &m_protectIds);
     DECL_OPTION("-protect-key", Set, &m_protectKey);

src/V3Options.h

@@ -253,6 +253,7 @@ private:
     bool m_pinsScBigUint = false;   // main switch: --pins-sc-biguint
     bool m_pinsUint8 = false;       // main switch: --pins-uint8
     bool m_ppComments = false;      // main switch: --pp-comments
+    bool m_profC = false;           // main switch: --prof-c
     bool m_profCFuncs = false;      // main switch: --prof-cfuncs
     bool m_profThreads = false;     // main switch: --prof-threads
     bool m_protectIds = false;      // main switch: --protect-ids
@@ -462,6 +463,7 @@ public:
     bool pinsScBigUint() const { return m_pinsScBigUint; }
     bool pinsUint8() const { return m_pinsUint8; }
     bool ppComments() const { return m_ppComments; }
+    bool profC() const { return m_profC; }
     bool profCFuncs() const { return m_profCFuncs; }
     bool profThreads() const { return m_profThreads; }
     bool protectIds() const { return m_protectIds; }

test_regress/t/t_prof.pl

@@ -10,6 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 scenarios(vlt_all => 1);
 
+# TODO below might no longer be requried as configure checks for -pg
 if ($ENV{VERILATOR_TEST_NO_GPROF}) {
     skip("Skipping due to VERILATOR_TEST_NO_GPROF");
 } else {
@@ -20,7 +21,7 @@ ok(1);
 
 sub dotest {
     compile(
-        verilator_flags2 => ["--stats --prof-cfuncs -CFLAGS '-pg' -LDFLAGS '-pg'"],
+        verilator_flags2 => ["--stats --prof-cfuncs"],
         );
 
     unlink $_ foreach (glob "$Self->{obj_dir}/gmon.out.*");

test_regress/t/t_profc.pl

@@ -0,0 +1,38 @@
+#!/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);
+
+top_filename("t_prof.v");
+
+ok(1);
+
+sub dotest {
+    compile(
+        verilator_flags2 => ["--stats --prof-c"],
+        );
+
+    unlink $_ foreach (glob "$Self->{obj_dir}/gmon.out.*");
+    setenv('GMON_OUT_PREFIX', "$Self->{obj_dir}/gmon.out");
+
+    execute(
+        check_finished => 1,
+        );
+
+    my $gmon_path;
+    $gmon_path = $_ foreach (glob "$Self->{obj_dir}/gmon.out.*");
+    $gmon_path or error("Profiler did not create a gmon.out");
+    (my $gmon_base = $gmon_path) =~ s!.*[/\\]!!;
+
+    run(cmd => ["cd $Self->{obj_dir} && gprof $Self->{VM_PREFIX} $gmon_base > gprof.out"],
+        check_finished => 0);
+}
+
+1;