synth: add debug flag -dc to not clean.

3 files changed, 9 insertions, 1 deletions

diff --git a/src/ghdldrv/ghdlsynth.adb b/src/ghdldrv/ghdlsynth.adb
index f6539d2c4..a260b2cd7 100644
--- a/src/ghdldrv/ghdlsynth.adb
+++ b/src/ghdldrv/ghdlsynth.adb
@@ -97,6 +97,9 @@ package body Ghdlsynth is
       elsif Option = "-di" then
          Flag_Debug_Noinference := True;
          Res := Option_Ok;
+      elsif Option = "-dc" then
+         Flag_Debug_Nocleanup := 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
index c5d11f83c..d87826f4d 100644
--- a/src/synth/synth-flags.ads
+++ b/src/synth/synth-flags.ads
@@ -20,4 +20,6 @@
 
 package Synth.Flags is
    Flag_Debug_Noinference : Boolean := False;
+
+   Flag_Debug_Nocleanup : Boolean := False;
 end Synth.Flags;
diff --git a/src/synth/synth-insts.adb b/src/synth/synth-insts.adb
index 5df7d4303..6e04fc2a8 100644
--- a/src/synth/synth-insts.adb
+++ b/src/synth/synth-insts.adb
@@ -32,6 +32,7 @@ with Vhdl.Utils; use Vhdl.Utils;
 with Vhdl.Annotations; use Vhdl.Annotations;
 with Vhdl.Errors;
 
+with Synth.Flags;
 with Synth.Values; use Synth.Values;
 with Synth.Environment; use Synth.Environment;
 with Synth.Stmts; use Synth.Stmts;
@@ -805,7 +806,9 @@ package body Synth.Insts is
       --  Remove unused gates.  This is not only an optimization but also
       --  a correctness point: there might be some unsynthesizable gates, like
       --  the one created for 'rising_egde (clk) and not rst'.
-      Netlists.Utils.Remove_Unused_Instances (Syn_Inst.M);
+      if not Flags.Flag_Debug_Nocleanup then
+         Netlists.Utils.Remove_Unused_Instances (Syn_Inst.M);
+      end if;
    end Synth_Instance;
 
    procedure Synth_All_Instances