synth: add synth-flags, add debug option -di.

3 files changed, 32 insertions, 1 deletions

diff --git a/src/ghdldrv/ghdlsynth.adb b/src/ghdldrv/ghdlsynth.adb
index 0f566ad6b..f6539d2c4 100644
--- a/src/ghdldrv/ghdlsynth.adb
+++ b/src/ghdldrv/ghdlsynth.adb
@@ -45,6 +45,7 @@ with Netlists.Disp_Vhdl;
 with Synthesis;
 with Synth.Disp_Vhdl;
 with Synth.Context; use Synth.Context;
+with Synth.Flags; use Synth.Flags;
 
 package body Ghdlsynth is
    type Out_Format is (Format_Raw, Format_Vhdl);
@@ -93,6 +94,9 @@ package body Ghdlsynth is
       elsif Option = "--out=vhdl" then
          Cmd.Oformat := Format_Vhdl;
          Res := Option_Ok;
+      elsif Option = "-di" then
+         Flag_Debug_Noinference := True;
+         Res := Option_Ok;
       else
          Decode_Option (Command_Lib (Cmd), Option, Arg, Res);
       end if;
diff --git a/src/synth/synth-flags.ads b/src/synth/synth-flags.ads
new file mode 100644
index 000000000..c5d11f83c
--- /dev/null
+++ b/src/synth/synth-flags.ads
@@ -0,0 +1,23 @@
+--  Flags for synthesis.
+--  Copyright (C) 2019 Tristan Gingold
+--
+--  This file is part of GHDL.
+--
+--  This program is free software; you can redistribute it and/or modify
+--  it under the terms of the GNU General Public License as published by
+--  the Free Software Foundation; either version 2 of the License, or
+--  (at your option) any later version.
+--
+--  This program is distributed in the hope that it will be useful,
+--  but WITHOUT ANY WARRANTY; without even the implied warranty of
+--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+--  GNU General Public License for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with this program; if not, write to the Free Software
+--  Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+--  MA 02110-1301, USA.
+
+package Synth.Flags is
+   Flag_Debug_Noinference : Boolean := False;
+end Synth.Flags;
diff --git a/src/synth/synth-inference.adb b/src/synth/synth-inference.adb
index 5017a2726..56f1fca3d 100644
--- a/src/synth/synth-inference.adb
+++ b/src/synth/synth-inference.adb
@@ -22,6 +22,8 @@ with Netlists.Utils; use Netlists.Utils;
 with Netlists.Gates; use Netlists.Gates;
 with Netlists.Gates_Ports; use Netlists.Gates_Ports;
 
+with Synth.Flags;
+
 package body Synth.Inference is
    --  DFF inference.
    --  As an initial implementation, the following 'styles' must be
@@ -352,7 +354,9 @@ package body Synth.Inference is
       Enable : Net;
    begin
       Find_Longest_Loop (Val, Prev_Val, Last_Mux, Len);
-      if Len <= 0 then
+      if Len <= 0
+        or else Flags.Flag_Debug_Noinference
+      then
          --  No logical loop or self assignment.
          Add_Conc_Assign (Wid, Val, Off, Stmt);
       else