synth: add --latches option to enable latches. Fix #938

2 files changed, 8 insertions, 1 deletions

diff --git a/src/synth/netlists-inference.adb b/src/synth/netlists-inference.adb
index 6da07e19a..383211684 100644
--- a/src/synth/netlists-inference.adb
+++ b/src/synth/netlists-inference.adb
@@ -780,7 +780,11 @@ package body Netlists.Inference is
       else
          Name := Get_Instance_Name (Get_Net_Parent (Prev_Val));
       end if;
-      Error_Msg_Synth (Loc, "latch infered for net %n", +Name);
+
+      if not Flag_Latches then
+         Error_Msg_Synth
+           (Loc, "latch infered for net %n (use --latches)", +Name);
+      end if;
 
       return Val;
    end Infere_Latch;
diff --git a/src/synth/netlists-inference.ads b/src/synth/netlists-inference.ads
index 61eab9fb2..ae671a0ac 100644
--- a/src/synth/netlists-inference.ads
+++ b/src/synth/netlists-inference.ads
@@ -20,6 +20,9 @@ with Netlists; use Netlists;
 with Netlists.Builders; use Netlists.Builders;
 
 package Netlists.Inference is
+   --  If True, latches are allowed.
+   Flag_Latches : Boolean := False;
+
    --  Walk the And-net N, and extract clock (posedge/negedge) if found.
    --  ENABLE is N without the clock.
    --  If not found, CLK and ENABLE are set to No_Net.