Verify blackbox context when rendering includes

Fixes #1945

changelog/2021-10-07T16_55_54+02_00_fix1945

@@ -0,0 +1 @@
+FIXED: valid field of TemplateFunction isn't checked for includes [#1945](https://github.com/clash-lang/clash-compiler/issues/1945)

clash-lib/src/Clash/Netlist/BlackBox/Util.hs

@@ -279,6 +279,14 @@ renderBlackBox libs imps includes bb bbCtx = do
       layout = LayoutOptions (AvailablePerLine 120 0.4)
   nms <-
     forM includes $ \((nm,_),inc) -> do
+      case verifyBlackBoxContext bbCtx inc of
+        Nothing -> return ()
+        Just err0 -> do
+          sp <- getSrcSpan
+          let err1 = concat [ "Couldn't instantiate blackbox for "
+                            , Data.Text.unpack (bbName bbCtx), ". Verification "
+                            , "procedure reported:\n\n" ++ err0 ]
+          throw (ClashException sp ($(curLoc) ++ err1) Nothing)
       let bbCtx' = bbCtx {bbQsysIncName = map Text.toStrict nms'}
       incForHash <- onBlackBox (renderTemplate bbCtx')
                                (\_name _hash (N.TemplateFunction _ _ f) -> do

tests/Main.hs

@@ -162,6 +162,10 @@ runClashTest = defaultMain $ clashTestRoot
               primitive for WrongReference.myMultiplyX. These names should be
               the same. |])
           }
+        , runTest "T1945" def{
+            hdlTargets=[VHDL]
+          , expectClashFail=Just (def, "Template function for returned False")
+          }
         ]
       , clashTestGroup "InvalidPrimitive"
         [ runTest "InvalidPrimitive" def{

tests/shouldfail/BlackBox/T1945.hs

@@ -0,0 +1,39 @@
+{-# LANGUAGE OverloadedStrings #-}
+module T1945 where
+
+import           Clash.Annotations.Primitive  (Primitive(..), HDL(..), hasBlackBox)
+import           Clash.Netlist.Types          (TemplateFunction (..))
+import           Clash.Prelude
+
+import           Data.String.Interpolate      (i)
+import           Data.String.Interpolate.Util (unindent)
+
+bb :: a -> a
+bb x = x
+{-# NOINLINE bb #-}
+{-# ANN bb hasBlackBox #-}
+{-# ANN bb (InlinePrimitive [VHDL,Verilog,SystemVerilog] $ unindent [i|
+   [ { "BlackBox" :
+        { "name" : "T1945.bb",
+          "kind" : "Expression",
+          "template": "~ARG[0]",
+          "includes" :
+            [ { "extension" : "bin"
+              , "name" : "mem"
+              , "format" : "Haskell"
+              , "templateFunction" : "T1945.tf"}
+
+            ]
+        }
+     }
+   ]
+   |]) #-}
+
+tf :: TemplateFunction
+tf = TemplateFunction used valid (const (pure "QQ"))
+ where
+  used = [0]
+  valid = const False
+
+topEntity :: Bool -> Bool
+topEntity = bb