Avoid generating #includes for imports that are used only for their annotations.

compiler/src/Compiler.hs

@@ -785,6 +785,8 @@ compileFile name decls annotations importMap =
             { fileName = name
             , fileId = theId
             , fileImports = Map.elems importMap
+            , fileRuntimeImports =
+                Set.fromList $ map fileName $ concatMap descRuntimeImports members
             , fileUsings     = [d | DescUsing     d <- members]
             , fileConstants  = [d | DescConstant  d <- members]
             , fileEnums      = [d | DescEnum      d <- members]

compiler/src/CxxGenerator.hs

@@ -30,6 +30,7 @@ import Data.FileEmbed(embedFile)
 import Data.Word(Word8)
 import qualified Data.Digest.MD5 as MD5
 import qualified Data.Map as Map
+import qualified Data.Set as Set
 import Data.Maybe(catMaybes, fromMaybe)
 import Data.Binary.IEEE754(floatToWord, doubleToWord)
 import Text.Printf(printf)
@@ -320,6 +321,8 @@ fileContext desc = mkStrContext context where
 
     namespace = maybe [] (splitOn "::") $ fileNamespace desc
 
+    isImportUsed (_, dep) = Set.member (fileName dep) (fileRuntimeImports desc)
+
     context "fileName" = MuVariable $ fileName desc
     context "fileBasename" = MuVariable $ takeBaseName $ fileName desc
     context "fileIncludeGuard" = MuVariable $
@@ -327,7 +330,8 @@ fileContext desc = mkStrContext context where
     context "fileNamespaces" = MuList $ map (namespaceContext context) namespace
     context "fileEnums" = MuList $ map (enumContext context) $ fileEnums desc
     context "fileTypes" = MuList $ map (typeContext context) flattenedMembers
-    context "fileImports" = MuList $ map (importContext context) $ Map.keys $ fileImportMap desc
+    context "fileImports" = MuList $ map (importContext context . fst)
+                          $ filter isImportUsed $ Map.toList $ fileImportMap desc
     context s = error ("Template variable not defined: " ++ s)
 
 headerTemplate :: String

compiler/src/Semantics.hs

@@ -113,6 +113,9 @@ descParent (DescBuiltinType _) = error "Builtin type has no parent."
 descParent DescBuiltinList = error "Builtin type has no parent."
 descParent DescBuiltinId = error "Builtin annotation has no parent."
 
+descFile (DescFile d) = d
+descFile desc = descFile $ descParent desc
+
 descAnnotations (DescFile      d) = fileAnnotations d
 descAnnotations (DescUsing     _) = Map.empty
 descAnnotations (DescConstant  d) = constantAnnotations d
@@ -129,6 +132,22 @@ descAnnotations (DescBuiltinType _) = Map.empty
 descAnnotations DescBuiltinList = Map.empty
 descAnnotations DescBuiltinId = Map.empty
 
+descRuntimeImports (DescFile      d) = error "Not to be called on files."
+descRuntimeImports (DescUsing     d) = usingRuntimeImports d
+descRuntimeImports (DescConstant  d) = constantRuntimeImports d
+descRuntimeImports (DescEnum      d) = enumRuntimeImports d
+descRuntimeImports (DescEnumerant d) = enumerantRuntimeImports d
+descRuntimeImports (DescStruct    d) = structRuntimeImports d
+descRuntimeImports (DescUnion     d) = unionRuntimeImports d
+descRuntimeImports (DescField     d) = fieldRuntimeImports d
+descRuntimeImports (DescInterface d) = interfaceRuntimeImports d
+descRuntimeImports (DescMethod    d) = methodRuntimeImports d
+descRuntimeImports (DescParam     d) = paramRuntimeImports d
+descRuntimeImports (DescAnnotation d) = annotationRuntimeImports d
+descRuntimeImports (DescBuiltinType _) = []
+descRuntimeImports DescBuiltinList = []
+descRuntimeImports DescBuiltinId = []
+
 type MemberMap = Map.Map String (Maybe Desc)
 
 lookupMember :: String -> MemberMap -> Maybe Desc
@@ -196,6 +215,12 @@ data TypeDesc = BuiltinType BuiltinType
               | InterfaceType InterfaceDesc
               | ListType TypeDesc
 
+typeRuntimeImports (BuiltinType _) = []
+typeRuntimeImports (EnumType d) = [descFile (DescEnum d)]
+typeRuntimeImports (StructType d) = [descFile (DescStruct d)]
+typeRuntimeImports (InterfaceType d) = [descFile (DescInterface d)]
+typeRuntimeImports (ListType d) = typeRuntimeImports d
+
 data PackingState = PackingState
     { packingHole1 :: Integer
     , packingHole8 :: Integer
@@ -307,6 +332,9 @@ data FileDesc = FileDesc
     { fileName :: String
     , fileId :: Maybe String
     , fileImports :: [FileDesc]
+    -- Set of imports which are used at runtime, i.e. not just for annotations.
+    -- The set contains file names matching files in fileImports.
+    , fileRuntimeImports :: Set.Set String
     , fileUsings :: [UsingDesc]
     , fileConstants :: [ConstantDesc]
     , fileEnums :: [EnumDesc]
@@ -324,6 +352,8 @@ data UsingDesc = UsingDesc
     , usingTarget :: Desc
     }
 
+usingRuntimeImports _ = []
+
 data ConstantDesc = ConstantDesc
     { constantName :: String
     , constantId :: Maybe String
@@ -333,6 +363,8 @@ data ConstantDesc = ConstantDesc
     , constantValue :: ValueDesc
     }
 
+constantRuntimeImports desc = typeRuntimeImports $ constantType desc
+
 data EnumDesc = EnumDesc
     { enumName :: String
     , enumId :: Maybe String
@@ -343,6 +375,8 @@ data EnumDesc = EnumDesc
     , enumStatements :: [Desc]
     }
 
+enumRuntimeImports desc = concatMap descRuntimeImports $ enumStatements desc
+
 data EnumerantDesc = EnumerantDesc
     { enumerantName :: String
     , enumerantId :: Maybe String
@@ -351,6 +385,8 @@ data EnumerantDesc = EnumerantDesc
     , enumerantAnnotations :: AnnotationMap
     }
 
+enumerantRuntimeImports _ = []
+
 data StructDesc = StructDesc
     { structName :: String
     , structId :: Maybe String
@@ -373,6 +409,8 @@ data StructDesc = StructDesc
     , structFieldPackingMap :: Map.Map Integer (Integer, PackingState)
     }
 
+structRuntimeImports desc = concatMap descRuntimeImports $ structStatements desc
+
 data UnionDesc = UnionDesc
     { unionName :: String
     , unionId :: Maybe String
@@ -389,6 +427,8 @@ data UnionDesc = UnionDesc
     , unionFieldDiscriminantMap :: Map.Map Integer Integer
     }
 
+unionRuntimeImports desc = concatMap descRuntimeImports $ unionStatements desc
+
 data FieldDesc = FieldDesc
     { fieldName :: String
     , fieldId :: Maybe String
@@ -402,6 +442,8 @@ data FieldDesc = FieldDesc
     , fieldAnnotations :: AnnotationMap
     }
 
+fieldRuntimeImports desc = typeRuntimeImports $ fieldType desc
+
 data InterfaceDesc = InterfaceDesc
     { interfaceName :: String
     , interfaceId :: Maybe String
@@ -417,6 +459,8 @@ data InterfaceDesc = InterfaceDesc
     , interfaceStatements :: [Desc]
     }
 
+interfaceRuntimeImports desc = concatMap descRuntimeImports $ interfaceStatements desc
+
 data MethodDesc = MethodDesc
     { methodName :: String
     , methodId :: Maybe String
@@ -427,6 +471,9 @@ data MethodDesc = MethodDesc
     , methodAnnotations :: AnnotationMap
     }
 
+methodRuntimeImports desc = typeRuntimeImports (methodReturnType desc) ++
+                            concatMap paramRuntimeImports (methodParams desc)
+
 data ParamDesc = ParamDesc
     { paramName :: String
     , paramId :: Maybe String
@@ -437,6 +484,8 @@ data ParamDesc = ParamDesc
     , paramAnnotations :: AnnotationMap
     }
 
+paramRuntimeImports desc = typeRuntimeImports $ paramType desc
+
 data AnnotationDesc = AnnotationDesc
     { annotationName :: String
     , annotationParent :: Desc
@@ -446,6 +495,8 @@ data AnnotationDesc = AnnotationDesc
     , annotationTargets :: Set.Set AnnotationTarget
     }
 
+annotationRuntimeImports desc = typeRuntimeImports $ annotationType desc
+
 type AnnotationMap = Map.Map String (AnnotationDesc, ValueDesc)
 
 descToCode :: String -> Desc -> String