Remove cgraph workarounds for nested functions that have a custom sta…

…tic chain.

gcc/d/ChangeLog

@@ -1,3 +1,18 @@
+2014-06-12  Iain Buclaw  <ibuclaw@gdcproject.org>
+
+	* d-codegen.cc(d_decl_context): Always return parent context for
+	functions nested in functions.
+	(is_degenerate_closure): Remove function.
+	(needs_static_chain): Remove function.
+	* d-decls.cc(FuncDeclaration::toSymbol): Remove workaround for cgraph
+	nesting structure, saving the original context decl.
+	* d-lang.h(D_DECL_STATIC_CHAIN): Remove macro.
+	* d-objfile.cc(Symbol::Symbol): Remove ScontextDecl field.
+	(FuncDeclaration::toObjFile): Remove workaround for cgraph nesting
+	structure, restoring the original context decl.  Delay building the
+	cgraph node until...
+	(d_finish_function): ... here, where the function is unnested.
+
 2014-06-11  Iain Buclaw  <ibuclaw@gdcproject.org>
 
 	* d-objfile.cc(d_finish_function): Update the callgraph to reflect

gcc/d/d-codegen.cc

@@ -37,19 +37,16 @@ tree
 d_decl_context (Dsymbol *dsym)
 {
   Dsymbol *parent = dsym;
-  AggregateDeclaration *ad;
 
   while ((parent = parent->toParent2()))
     {
+      // Nested functions.
       if (parent->isFuncDeclaration())
-	{
-	  FuncDeclaration *fd = dsym->isFuncDeclaration();
-	  if (fd && !needs_static_chain (fd))
-	    return NULL_TREE;
+	return parent->toSymbol()->Stree;
 
-	  return parent->toSymbol()->Stree;
-	}
-      else if ((ad = parent->isAggregateDeclaration()))
+      // Methods of classes or structs.
+      AggregateDeclaration *ad = parent->isAggregateDeclaration();
+      if (ad != NULL)
 	{
 	  tree context = ad->type->toCtype();
 	  // Want the underlying RECORD_TYPE.
@@ -58,11 +55,12 @@ d_decl_context (Dsymbol *dsym)
 
 	  return context;
 	}
-      else if (parent->isModule())
+
+      // We've reached the top-level module namespace.
+      // Set DECL_CONTEXT as the NAMESPACE_DECL of the enclosing module,
+      // but only for extern(D) symbols.
+      if (parent->isModule())
 	{
-	  // We've reached the top-level module namespace.
-	  // Set DECL_CONTEXT as the NAMESPACE_DECL of the enclosing
-	  // module, but only for extern(D) symbols.
 	  Declaration *decl = dsym->isDeclaration();
 	  if (decl != NULL && decl->linkage != LINKd)
 	    return NULL_TREE;
@@ -3450,85 +3448,6 @@ get_framedecl (FuncDeclaration *inner, FuncDeclaration *outer)
     }
 }
 
-// Special case: If a function returns a nested class with functions
-// but there are no "closure variables" the frontend (needsClosure)
-// returns false even though the nested class _is_ returned from the
-// function. (See case 4 in needsClosure)
-// A closure is strictly speaking not necessary, but we also can not
-// use a static function chain for functions in the nested class as
-// they can be called from outside. GCC's nested functions can't deal
-// with those kind of functions. We have to detect them manually here
-// and make sure we neither construct a static chain nor a closure.
-
-static bool
-is_degenerate_closure (FuncDeclaration *f)
-{
-  if (!f->needsClosure() && f->closureVars.dim == 0)
-  {
-    Type *tret = ((TypeFunction *) f->type)->next;
-    gcc_assert(tret);
-    tret = tret->toBasetype();
-    if (tret->ty == Tclass || tret->ty == Tstruct)
-    {
-      Dsymbol *st = tret->toDsymbol(NULL);
-      for (Dsymbol *s = st->parent; s; s = s->parent)
-      {
-	if (s == f)
-	  return true;
-      }
-    }
-  }
-  return false;
-}
-
-// Return true if function F needs to have the static chain passed to it.
-// This only applies to nested function handling provided by the GDC
-// front end (not D closures).
-
-bool
-needs_static_chain (FuncDeclaration *f)
-{
-  Dsymbol *s;
-  FuncDeclaration *pf = NULL;
-  TemplateInstance *ti = NULL;
-
-  if (f->isNested())
-    {
-      s = f->toParent();
-      ti = s->isTemplateInstance();
-      if (ti && ti->enclosing == NULL && ti->parent->isModule())
-	return false;
-
-      pf = f->toParent2()->isFuncDeclaration();
-      if (pf && !get_frameinfo (pf)->is_closure)
-	return true;
-    }
-
-  if (f->isStatic())
-    return false;
-
-  s = f->toParent2();
-
-  while (s)
-    {
-      AggregateDeclaration *ad = s->isAggregateDeclaration();
-      if (!ad || !ad->isNested())
-	break;
-
-      if (!s->isTemplateInstance())
-	break;
-
-      s = s->toParent2();
-      if ((pf = s->isFuncDeclaration())
-	  && !get_frameinfo (pf)->is_closure
-	  && !is_degenerate_closure (pf))
-	return true;
-    }
-
-  return false;
-}
-
-
 // Construct a WrappedExp, whose components are an EXP_NODE, which contains
 // a list of instructions in GCC to be passed through.
 

gcc/d/d-codegen.h

@@ -180,8 +180,6 @@ extern tree build_vthis (Dsymbol *decl, FuncDeclaration *fd, Expression *e);
 // Static chain for nested functions
 extern tree get_frame_for_symbol (FuncDeclaration *func, Dsymbol *sym);
 
-extern bool needs_static_chain (FuncDeclaration *f);
-
 // Local variables
 extern void build_local_var (VarDeclaration *vd, FuncDeclaration *fd);
 extern tree build_local_temp (tree type);

gcc/d/d-decls.cc

@@ -328,14 +328,6 @@ FuncDeclaration::toSymbol (void)
 
       csym->Stree = fndecl;
 
-      if (needs_static_chain (this))
-	{
-	  D_DECL_STATIC_CHAIN (fndecl) = 1;
-	  // Save context and set decl_function_context for cgraph.
-	  csym->ScontextDecl = DECL_CONTEXT (fndecl);
-	  DECL_CONTEXT (fndecl) = decl_function_context (fndecl);
-	}
-
       TREE_TYPE (fndecl) = ftype->toCtype();
       DECL_LANG_SPECIFIC (fndecl) = build_d_decl_lang_specific (this);
       d_keep (fndecl);

gcc/d/d-lang.h

@@ -79,9 +79,6 @@ extern GTY(()) tree d_eh_personality_decl;
    is not affected by -femit-templates. */
 #define D_DECL_IS_TEMPLATE(NODE) (DECL_LANG_FLAG_1 (NODE))
 
-/* True if a custom static chain has been set-up for function.  */
-#define D_DECL_STATIC_CHAIN(NODE) (DECL_LANG_FLAG_3 (FUNCTION_DECL_CHECK (NODE)))
-
 /* The D front-end does not use the 'binding level' system for a symbol table,
    It is only needed to get debugging information for local variables and
    otherwise support the backend. */

gcc/d/d-objfile.cc

@@ -54,7 +54,6 @@ Symbol::Symbol (void)
   this->Sreadonly = false;
 
   this->Stree = NULL_TREE;
-  this->ScontextDecl = NULL_TREE;
   this->SframeField = NULL_TREE;
   this->SnamedResult = NULL_TREE;
 
@@ -1298,16 +1297,6 @@ FuncDeclaration::toObjFile (int)
 
   if (!errorcount && !global.errors)
     {
-      // Build cgraph for function.
-      cgraph_get_create_node (fndecl);
-
-      // Set original decl context back to true context
-      if (D_DECL_STATIC_CHAIN (fndecl))
-	{
-	  Declaration *decl = lang_ddecl (fndecl);
-	  DECL_CONTEXT (fndecl) = decl->toSymbol()->ScontextDecl;
-	}
-
       // Dump the D-specific tree IR.
       int local_dump_flags;
       FILE *dump_file = dump_begin (TDI_original, &local_dump_flags);
@@ -1901,7 +1890,8 @@ d_finish_function (FuncDeclaration *fd)
 	static_dtor_list.safe_push (fd);
     }
 
-  struct cgraph_node *node = cgraph_get_node (decl);
+  // Build cgraph for function.
+  struct cgraph_node *node = cgraph_get_create_node (decl);
 
   // For nested functions update the cgraph to reflect unnesting,
   // which is handled by the front-end.

gcc/d/d-objfile.h

@@ -58,9 +58,6 @@ struct Symbol
   // Our GNU backend tree for the symbol.
   tree Stree;
 
-  // The real DECL_CONTEXT of the symbol, if the context of Stree differs.
-  tree ScontextDecl;
-
   // FIELD_DECL in frame struct that this variable is allocated in.
   tree SframeField;