Mutual resources

WYBE.md

@@ -1559,11 +1559,16 @@ A resource can be declared at the level of a module, as follows:
 
 > `resource` *name*`:`*type*
 
-It may optionally specify an initial value, in which case the resource is
-defined throughout the execution of the program.
+It may optionally specify an initial value:
 
 > `resource` *name*`:`*type* `=` *expr*
 
+In this case, the resource is
+defined in any top level code in that module, as well as any top level code in
+any module that `use`s this module, but not in any module that this module
+`use`s.  The latter restriction is necessary because when two modules depend on
+one another, the order in which their resources are initialised is unspecified.
+
 A resource may be exported, allowing it to be referred to in other modules, by
 preceding the `resource` declaration with the `pub` keyword.
 

src/Normalise.hs

@@ -170,7 +170,7 @@ completeNormalisation :: [ModSpec] -> Compiler ()
 completeNormalisation modSCC = do
     logNormalise $ "Completing normalisation of modules " ++ showModSpecs modSCC
     completeTypeNormalisation modSCC
-    mapM_ (normaliseModMain `inModule`) modSCC
+    mapM_ (normaliseModMain modSCC `inModule`) modSCC
     mapM_ (transformModuleProcs flattenProcBody) modSCC
 
 
@@ -442,18 +442,19 @@ typeRepresentation _ _          = Address
 
 
 ----------------------------------------------------------------
--- Generating top-level code for the current module
+-- Generating top-level code for the current module, given a list of all
+-- the modules in the same module dependency SCC.
 
-normaliseModMain :: Compiler ()
-normaliseModMain = do
+normaliseModMain :: [ModSpec] -> Compiler ()
+normaliseModMain modSCC = do
     stmts <- getModule stmtDecls
     modSpec <- getModuleSpec
     logNormalise $ "Completing main normalisation of module "
                    ++ showModSpec modSpec
     let initBody = List.reverse stmts
     logNormalise $ "Top-level statements = " ++ show initBody
     unless (List.null stmts) $ do
-        resources <- initResources
+        resources <- initResources modSCC
         logNormalise $ "Initialised resources in main code for module "
                         ++ showModSpec modSpec
                         ++ ": " ++ show resources
@@ -463,9 +464,11 @@ normaliseModMain = do
 
 -- |The resources available at the top level of this module, plus the
 -- initialisations to be performed before executing any code that uses this
--- module.
-initResources :: Compiler (Set ResourceFlowSpec)
-initResources = do
+-- module.  All resources initialised by the current module are taken to be
+-- outputs, and all resources defined by modules used by this module but not in
+-- the same SCC are taken as inputs.
+initResources :: [ModSpec] -> Compiler (Set ResourceFlowSpec)
+initResources modSCC = do
     thisMod <- getModule modSpec
     mods <- getModuleImplementationField (Map.keys . modImports)
     mods' <- (mods ++) . concat <$> mapM descendentModules mods
@@ -474,7 +477,8 @@ initResources = do
     (localInitialised,visibleInitialised) <- initialisedResources
     let visibleInitSet = Map.keysSet visibleInitialised
     let localInitSet = Map.keysSet localInitialised
-    let importedInitSet = visibleInitSet Set.\\ localInitSet
+    let importedInitSet = Set.filter (not . (`elem` modSCC) . resourceMod)
+                    $ visibleInitSet Set.\\ localInitSet
     logNormalise $ "in initResources, initialised resources = "
                    ++ show visibleInitSet
     logNormalise $ "            initialised local resources = "

test-cases/final-dump/mutual_res_a.exp

@@ -0,0 +1,81 @@
+======================================================================
+AFTER EVERYTHING:
+ Module mutual_res_a
+  representation  : (not a type)
+  public submods  : 
+  public resources: a_res: mutual_res_a.a_res
+  public procs    : mutual_res_a.<0>
+  imports         : use mutual_res_b
+                    use wybe
+  resources       : a_res: fromList [(mutual_res_a.a_res,wybe.int = 42 @mutual_res_a:nn:nn @mutual_res_a:nn:nn)]
+  procs           : 
+
+module top-level code > public {inline,semipure} (0 calls)
+0: mutual_res_a.<0>
+()<{}; {<<mutual_res_a.a_res>>}; {}>:
+  AliasPairs: []
+  InterestingCallProperties: []
+    foreign lpvm store(42:wybe.int, <<mutual_res_a.a_res>>:wybe.int) @mutual_res_a:nn:nn
+
+  LLVM code       :
+
+; ModuleID = 'mutual_res_a'
+
+
+
+
+
+@"resource#mutual_res_a.a_res" =    global i64 undef
+
+
+declare external ccc  i8* @wybe_malloc(i32)    
+
+
+declare external ccc  void @llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i1)    
+
+
+define external fastcc  void @"mutual_res_a.<0>"() alwaysinline   {
+entry:
+  store  i64 42, i64* @"resource#mutual_res_a.a_res" 
+  ret void 
+}
+--------------------------------------------------
+ Module mutual_res_b
+  representation  : (not a type)
+  public submods  : 
+  public resources: b_res: mutual_res_b.b_res
+  public procs    : mutual_res_b.<0>
+  imports         : use mutual_res_a
+                    use wybe
+  resources       : b_res: fromList [(mutual_res_b.b_res,wybe.char = 'c' @mutual_res_b:nn:nn @mutual_res_b:nn:nn)]
+  procs           : 
+
+module top-level code > public {inline,semipure} (0 calls)
+0: mutual_res_b.<0>
+()<{}; {<<mutual_res_b.b_res>>}; {}>:
+  AliasPairs: []
+  InterestingCallProperties: []
+    foreign lpvm store('c':wybe.char, <<mutual_res_b.b_res>>:wybe.char) @mutual_res_b:nn:nn
+
+  LLVM code       :
+
+; ModuleID = 'mutual_res_b'
+
+
+
+
+
+@"resource#mutual_res_b.b_res" =    global i8 undef
+
+
+declare external ccc  i8* @wybe_malloc(i32)    
+
+
+declare external ccc  void @llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i1)    
+
+
+define external fastcc  void @"mutual_res_b.<0>"() alwaysinline   {
+entry:
+  store  i8 99, i8* @"resource#mutual_res_b.b_res" 
+  ret void 
+}

test-cases/final-dump/mutual_res_a.wybe

@@ -0,0 +1,2 @@
+use mutual_res_b
+pub resource a_res:int = 42

test-cases/final-dump/mutual_res_b.exp

@@ -0,0 +1,81 @@
+======================================================================
+AFTER EVERYTHING:
+ Module mutual_res_a
+  representation  : (not a type)
+  public submods  : 
+  public resources: a_res: mutual_res_a.a_res
+  public procs    : mutual_res_a.<0>
+  imports         : use mutual_res_b
+                    use wybe
+  resources       : a_res: fromList [(mutual_res_a.a_res,wybe.int = 42 @mutual_res_a:nn:nn @mutual_res_a:nn:nn)]
+  procs           : 
+
+module top-level code > public {inline,semipure} (0 calls)
+0: mutual_res_a.<0>
+()<{}; {<<mutual_res_a.a_res>>}; {}>:
+  AliasPairs: []
+  InterestingCallProperties: []
+    foreign lpvm store(42:wybe.int, <<mutual_res_a.a_res>>:wybe.int) @mutual_res_a:nn:nn
+
+  LLVM code       :
+
+; ModuleID = 'mutual_res_a'
+
+
+
+
+
+@"resource#mutual_res_a.a_res" =    global i64 undef
+
+
+declare external ccc  i8* @wybe_malloc(i32)    
+
+
+declare external ccc  void @llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i1)    
+
+
+define external fastcc  void @"mutual_res_a.<0>"() alwaysinline   {
+entry:
+  store  i64 42, i64* @"resource#mutual_res_a.a_res" 
+  ret void 
+}
+--------------------------------------------------
+ Module mutual_res_b
+  representation  : (not a type)
+  public submods  : 
+  public resources: b_res: mutual_res_b.b_res
+  public procs    : mutual_res_b.<0>
+  imports         : use mutual_res_a
+                    use wybe
+  resources       : b_res: fromList [(mutual_res_b.b_res,wybe.char = 'c' @mutual_res_b:nn:nn @mutual_res_b:nn:nn)]
+  procs           : 
+
+module top-level code > public {inline,semipure} (0 calls)
+0: mutual_res_b.<0>
+()<{}; {<<mutual_res_b.b_res>>}; {}>:
+  AliasPairs: []
+  InterestingCallProperties: []
+    foreign lpvm store('c':wybe.char, <<mutual_res_b.b_res>>:wybe.char) @mutual_res_b:nn:nn
+
+  LLVM code       :
+
+; ModuleID = 'mutual_res_b'
+
+
+
+
+
+@"resource#mutual_res_b.b_res" =    global i8 undef
+
+
+declare external ccc  i8* @wybe_malloc(i32)    
+
+
+declare external ccc  void @llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i1)    
+
+
+define external fastcc  void @"mutual_res_b.<0>"() alwaysinline   {
+entry:
+  store  i8 99, i8* @"resource#mutual_res_b.b_res" 
+  ret void 
+}

test-cases/final-dump/mutual_res_b.wybe

@@ -0,0 +1,2 @@
+use mutual_res_a
+pub resource b_res:char = 'c'