Use Function instead of TraitItemFunc or TraitItemMethod

gcc/rust/ChangeLog:

	* ast/rust-item.h (RUST_AST_ITEM_H):
	Make get_definition() public.
	* backend/rust-compile-implitem.cc (CompileTraitItem::visit):
	Use Function instead of TraitItemFunc.
	* backend/rust-compile-implitem.h:
	Add visitor for HIR::Function.
	* backend/rust-mangle-v0.cc (v0_path):
	Rename get_item_kind() to get trait_item_kind().
	* checks/errors/rust-ast-validation.cc (ASTValidation::visit):
	TRAIT is valid context for function as it will be used instead
	of TraitItemFunc.
	* hir/rust-ast-lower-implitem.h:
	Lower Function as a trait item.
	* hir/tree/rust-hir-item.h (class Function):
	Make Function inherit from TraitItem and add necessary
	functions, also add necessary parameters for constructors.
	* hir/tree/rust-hir-visitor.h:
	Add vistor for Function in HIRTraitItemVisitor.
	* hir/tree/rust-hir.cc (Function::accept_vis):
	Add accept_vis for Function.
	* hir/tree/rust-hir.h:
	Rename get_item_kind() to get trait_item_kind().
	* parse/rust-parse-impl.h (Parser::parse_trait_item):
	Return AST::Function instead of AST::TraitItemFunc or
	AST::TriatItemMethod.
	* typecheck/rust-hir-dot-operator.cc (MethodResolver::select):
	Rename get_item_kind() to get trait_item_kind().
	* typecheck/rust-hir-trait-reference.cc (TraitItemReference::get_tyty):
	Use HIR::Function instead of HIR::TraitItemFunc.
	* typecheck/rust-hir-trait-reference.h:
	Add functions for Function instead of TraitItemFunc.
	* typecheck/rust-hir-trait-resolve.cc (ResolveTraitItemToRef::visit):
	Add visit to Function.
	(TraitItemReference::on_resolved):
	Use HIR::Function instead of HIR::TraitItemFunc.
	(TraitItemReference::resolve_item):
	Add resolve_item() for Function.
	* typecheck/rust-hir-trait-resolve.h:
	Add visitor for Function.
	* typecheck/rust-hir-type-check.cc (TraitItemReference::get_type_from_fn):
	Add overload for Function.
	* typecheck/rust-tyty.cc (ClosureType::setup_fn_once_output):
	Rename get_item_kind() to get trait_item_kind().

Signed-off-by: Kushal Pal <kushalpal109@gmail.com>

Author: braw-lee

gcc/rust/ast/rust-item.h

@@ -19,12 +19,14 @@
 #ifndef RUST_AST_ITEM_H
 #define RUST_AST_ITEM_H
 
+#include "optional.h"
 #include "rust-ast.h"
 #include "rust-hir-map.h"
 #include "rust-mapping-common.h"
 #include "rust-path.h"
 #include "rust-common.h"
 #include "rust-expr.h"
+#include <memory>
 
 namespace Rust {
 namespace AST {
@@ -1323,6 +1325,8 @@ class Function : public VisItem, public TraitItem
 
   bool has_body () const { return function_body.has_value (); }
 
+  tl::optional<std::unique_ptr<BlockExpr>>& get_definition ()  { return function_body; }
+
   // Returns node_id, function is needed as VisItem and TraitItem both have
   // get_node_id()
   NodeId get_node_id () const { return VisItem::node_id; }
@@ -1394,12 +1398,6 @@ class Function : public VisItem, public TraitItem
     return generic_params;
   }
 
-  // TODO: is this better? Or is a "vis_block" better?
-  tl::optional<std::unique_ptr<BlockExpr>> &get_definition ()
-  {
-    return function_body;
-  }
-
   const FunctionQualifiers &get_qualifiers () const { return qualifiers; }
 
   FunctionQualifiers &get_qualifiers () { return qualifiers; }

gcc/rust/backend/rust-compile-implitem.cc

@@ -42,6 +42,54 @@ CompileTraitItem::visit (HIR::TraitItemConst &constant)
   reference = const_expr;
 }
 
+void
+CompileTraitItem::visit (HIR::Function &func)
+{
+  rust_assert (concrete->get_kind () == TyTy::TypeKind::FNDEF);
+  TyTy::FnType *fntype = static_cast<TyTy::FnType *> (concrete);
+  fntype->monomorphize ();
+  // items can be forward compiled which means we may not need to invoke this
+  // code. We might also have already compiled this generic function as well.
+  tree lookup = NULL_TREE;
+  if (ctx->lookup_function_decl (fntype->get_ty_ref (), &lookup,
+				 fntype->get_id (), fntype))
+    {
+      // has this been added to the list then it must be finished
+      if (ctx->function_completed (lookup))
+	{
+	  tree dummy = NULL_TREE;
+	  if (!ctx->lookup_function_decl (fntype->get_ty_ref (), &dummy))
+	    {
+	      ctx->insert_function_decl (fntype, lookup);
+	    }
+
+	  reference = address_expression (lookup, ref_locus);
+	  return;
+	}
+    }
+
+  if (fntype->has_substitutions_defined ())
+    {
+      // override the Hir Lookups for the substituions in this context
+      fntype->override_context ();
+    }
+
+  const Resolver::CanonicalPath *canonical_path = nullptr;
+  bool ok = ctx->get_mappings ()->lookup_canonical_path (
+    func.get_mappings ().get_nodeid (), &canonical_path);
+  rust_assert (ok);
+
+  // FIXME: How do we get the proper visibility here?
+  auto vis = HIR::Visibility (HIR::Visibility::VisType::PUBLIC);
+  tree fndecl
+    = compile_function (func.get_function_name ().as_string (),
+			func.get_self (), func.get_function_params (),
+			func.get_qualifiers (), vis,
+			func.get_outer_attrs (), func.get_locus (),
+			func.get_definition ().get (), canonical_path, fntype);
+  reference = address_expression (fndecl, ref_locus);
+}
+
 void
 CompileTraitItem::visit (HIR::TraitItemFunc &func)
 {

gcc/rust/backend/rust-compile-implitem.h

@@ -69,6 +69,7 @@ class CompileTraitItem : public HIRCompileBase, public HIR::HIRTraitItemVisitor
 
   void visit (HIR::TraitItemConst &constant) override;
   void visit (HIR::TraitItemFunc &func) override;
+  void visit (HIR::Function &func) override;
 
   void visit (HIR::TraitItemType &typ) override {}
 

gcc/rust/backend/rust-mangle-v0.cc

@@ -410,7 +410,7 @@ v0_path (Rust::Compile::Context *ctx, const TyTy::BaseType *ty,
       }
     else if (trait_item != nullptr)
       {
-	switch (trait_item->get_item_kind ())
+	switch (trait_item->get_trait_item_kind ())
 	  {
 	    case HIR::TraitItem::FUNC: {
 	      HIR::Function *fn = static_cast<HIR::Function *> (impl_item);

gcc/rust/checks/errors/rust-ast-validation.cc

@@ -96,7 +96,7 @@ void
 ASTValidation::visit (AST::Function &function)
 {
   std::set<Context> valid_context
-    = {Context::INHERENT_IMPL, Context::TRAIT_IMPL};
+    = {Context::INHERENT_IMPL, Context::TRAIT_IMPL, Context::TRAIT};
 
   const auto &qualifiers = function.get_qualifiers ();
   if (qualifiers.is_async () && qualifiers.is_const ())

gcc/rust/hir/rust-ast-lower-implitem.h

@@ -23,6 +23,7 @@
 #include "rust-ast-lower-expr.h"
 #include "rust-ast-lower-pattern.h"
 #include "rust-ast-lower-block.h"
+#include "rust-ast-lower.h"
 #include "rust-item.h"
 
 namespace Rust {
@@ -240,6 +241,81 @@ class ASTLowerTraitItem : public ASTLoweringBase
     return resolver.translated;
   }
 
+  void visit (AST::Function &function) override
+  {
+    std::vector<std::unique_ptr<HIR::WhereClauseItem> > where_clause_items;
+    HIR::WhereClause where_clause (std::move (where_clause_items));
+    HIR::FunctionQualifiers qualifiers
+      = lower_qualifiers (function.get_qualifiers ());
+
+    std::vector<std::unique_ptr<HIR::GenericParam> > generic_params;
+    if (function.has_generics ())
+      {
+	generic_params = lower_generic_params (function.get_generic_params ());
+      }
+
+    std::unique_ptr<HIR::Type> return_type
+      = function.has_return_type () ? std::unique_ptr<HIR::Type> (
+	  ASTLoweringType::translate (function.get_return_type ().get ()))
+				    : nullptr;
+
+    HIR::SelfParam self_param = lower_self (function.get_self_param ());
+    std::vector<HIR::FunctionParam> function_params;
+    for (auto &p : function.get_function_params ())
+      {
+	if (p->is_variadic () || p->is_self ())
+	  continue;
+
+	auto param = static_cast<AST::FunctionParam *> (p.get ());
+
+	auto translated_pattern = std::unique_ptr<HIR::Pattern> (
+	  ASTLoweringPattern::translate (param->get_pattern ().get ()));
+	auto translated_type = std::unique_ptr<HIR::Type> (
+	  ASTLoweringType::translate (param->get_type ().get ()));
+
+	auto crate_num = mappings->get_current_crate ();
+	Analysis::NodeMapping mapping (crate_num, param->get_node_id (),
+				       mappings->get_next_hir_id (crate_num),
+				       UNKNOWN_LOCAL_DEFID);
+
+	auto hir_param
+	  = HIR::FunctionParam (mapping, std::move (translated_pattern),
+				std::move (translated_type),
+				param->get_locus ());
+	function_params.push_back (std::move (hir_param));
+      }
+
+    bool terminated = false;
+    std::unique_ptr<HIR::BlockExpr> block_expr
+      = function.has_body () ? std::unique_ptr<HIR::BlockExpr> (
+	  ASTLoweringBlock::translate (function.get_definition ()->get (),
+				       &terminated))
+			     : nullptr;
+
+    auto crate_num = mappings->get_current_crate ();
+    Analysis::NodeMapping mapping (crate_num, function.get_node_id (),
+				   mappings->get_next_hir_id (crate_num),
+				   mappings->get_next_localdef_id (crate_num));
+
+    HIR::Visibility vis = translate_visibility (function.get_visibility ());
+    HIR::Function *trait_item
+      = new HIR::Function (mapping, function.get_function_name (),
+			   std::move (qualifiers), std::move (generic_params),
+			   std::move (function_params), std::move (return_type),
+			   std::move (where_clause), std::move (block_expr),
+			   vis, function.get_outer_attrs (), self_param,
+			   function.get_locus ());
+
+    translated = trait_item;
+
+    // add the mappings for the function params at the end
+    for (auto &param : trait_item->get_function_params ())
+      {
+	mappings->insert_hir_param (&param);
+	mappings->insert_location (mapping.get_hirid (), param.get_locus ());
+      }
+  }
+
   void visit (AST::TraitItemFunc &func) override
   {
     AST::TraitFunctionDecl &ref = func.get_trait_function_decl ();

gcc/rust/hir/tree/rust-hir-item.h

@@ -25,6 +25,7 @@
 #include "rust-hir-expr.h"
 #include "rust-hir.h"
 #include "rust-hir-path.h"
+#include <memory>
 
 namespace Rust {
 namespace HIR {
@@ -1081,7 +1082,7 @@ class UseDeclaration : public VisItem
 class LetStmt;
 
 // Rust function declaration HIR node
-class Function : public VisItem, public ImplItem
+class Function : public VisItem, public ImplItem, public TraitItem
 {
   FunctionQualifiers qualifiers;
   Identifier function_name;
@@ -1115,6 +1116,40 @@ class Function : public VisItem, public ImplItem
 
   ItemKind get_item_kind () const override { return ItemKind::Function; }
 
+  TraitItemKind get_trait_item_kind () const override
+  {
+    return TraitItemKind::FUNC;
+  }
+
+  const std::string trait_identifier () const override
+  {
+    return function_name.as_string ();
+  }
+
+  location_t get_trait_locus () const override { return locus; }
+
+  AST::AttrVec &get_outer_attrs () override final { return outer_attrs; }
+
+  const AST::AttrVec &get_outer_attrs () const override final
+  {
+    return outer_attrs;
+  }
+
+  // Returns mappings, this function is needed otherwise call is ambigious as
+  // both VisItem and TraiItem have this function
+  const Analysis::NodeMapping &get_mappings () const
+  {
+    return VisItem::get_mappings();
+  }
+
+  // Returns whether function has a body
+  bool has_body() const { return function_body != nullptr; }
+
+  // Returns function body/definition
+  std::unique_ptr<BlockExpr>& get_body () { return function_body; }
+
+  SelfParam& get_self() { return self; }
+
   // Mega-constructor with all possible fields
   Function (Analysis::NodeMapping mappings, Identifier function_name,
 	    FunctionQualifiers qualifiers,
@@ -1123,8 +1158,8 @@ class Function : public VisItem, public ImplItem
 	    std::unique_ptr<Type> return_type, WhereClause where_clause,
 	    std::unique_ptr<BlockExpr> function_body, Visibility vis,
 	    AST::AttrVec outer_attrs, SelfParam self, location_t locus)
-    : VisItem (std::move (mappings), std::move (vis), std::move (outer_attrs)),
-      qualifiers (std::move (qualifiers)),
+    : VisItem (mappings, std::move (vis), std::move (outer_attrs)),
+      TraitItem (std::move (mappings)), qualifiers (std::move (qualifiers)),
       function_name (std::move (function_name)),
       generic_params (std::move (generic_params)),
       function_params (std::move (function_params)),
@@ -1136,7 +1171,7 @@ class Function : public VisItem, public ImplItem
 
   // Copy constructor with clone
   Function (Function const &other)
-    : VisItem (other), qualifiers (other.qualifiers),
+    : VisItem (other), TraitItem (other), qualifiers (other.qualifiers),
       function_name (other.function_name),
       function_params (other.function_params),
       where_clause (other.where_clause),
@@ -1158,6 +1193,7 @@ class Function : public VisItem, public ImplItem
   Function &operator= (Function const &other)
   {
     VisItem::operator= (other);
+    TraitItem::operator= (other);
     function_name = other.function_name;
     qualifiers = other.qualifiers;
     function_params = other.function_params;
@@ -1188,12 +1224,13 @@ class Function : public VisItem, public ImplItem
 
   void accept_vis (HIRFullVisitor &vis) override;
   void accept_vis (HIRImplVisitor &vis) override;
+  void accept_vis (HIRTraitItemVisitor &vis) override;
   void accept_vis (HIRStmtVisitor &vis) override;
   void accept_vis (HIRVisItemVisitor &vis) override;
 
   Analysis::NodeMapping get_impl_mappings () const override
   {
-    return get_mappings ();
+    return VisItem::get_mappings ();
   };
 
   std::vector<FunctionParam> &get_function_params () { return function_params; }
@@ -1246,6 +1283,11 @@ class Function : public VisItem, public ImplItem
   {
     return new Function (*this);
   }
+
+  Function *clone_trait_item_impl () const override
+  {
+    return new Function (*this);
+  }
 };
 
 // Rust type alias (i.e. typedef) HIR node
@@ -2400,7 +2442,7 @@ class TraitItemFunc : public TraitItem
     return decl.get_function_name ().as_string ();
   }
 
-  TraitItemKind get_item_kind () const override final
+  TraitItemKind get_trait_item_kind () const override final
   {
     return TraitItemKind::FUNC;
   }
@@ -2487,7 +2529,7 @@ class TraitItemConst : public TraitItem
     return name.as_string ();
   }
 
-  TraitItemKind get_item_kind () const override final
+  TraitItemKind get_trait_item_kind () const override final
   {
     return TraitItemKind::CONST;
   }
@@ -2579,7 +2621,7 @@ class TraitItemType : public TraitItem
     return name.as_string ();
   }
 
-  TraitItemKind get_item_kind () const override final
+  TraitItemKind get_trait_item_kind () const override final
   {
     return TraitItemKind::TYPE;
   }

gcc/rust/hir/tree/rust-hir-visitor.h

@@ -311,6 +311,7 @@ class HIRExternalItemVisitor
 class HIRTraitItemVisitor
 {
 public:
+  virtual void visit (Function &item) = 0;
   virtual void visit (TraitItemFunc &item) = 0;
   virtual void visit (TraitItemConst &item) = 0;
   virtual void visit (TraitItemType &item) = 0;

gcc/rust/hir/tree/rust-hir.cc

@@ -4986,6 +4986,12 @@ Function::accept_vis (HIRImplVisitor &vis)
   vis.visit (*this);
 }
 
+void
+Function::accept_vis (HIRTraitItemVisitor &vis)
+{
+  vis.visit (*this);
+}
+
 void
 Union::accept_vis (HIRStmtVisitor &vis)
 {

gcc/rust/hir/tree/rust-hir.h

@@ -821,7 +821,7 @@ class TraitItem : public Node, public FullVisitable
 
   virtual location_t get_trait_locus () const = 0;
 
-  virtual TraitItemKind get_item_kind () const = 0;
+  virtual TraitItemKind get_trait_item_kind () const = 0;
 
   virtual AST::AttrVec &get_outer_attrs () = 0;
   virtual const AST::AttrVec &get_outer_attrs () const = 0;