Remove dead code associated with AST::ExternalFunctionItem

gcc/rust/ChangeLog:

	* ast/rust-ast-collector.cc (TokenCollector::visit):
	Remove dead code.
	* ast/rust-ast-collector.h: Likewise.
	* ast/rust-ast-full-decls.h (class ExternalFunctionItem):
	Likewise.
	* ast/rust-ast-visitor.cc (DefaultASTVisitor::visit):
	Likewise.
	* ast/rust-ast-visitor.h: Likewise.
	* ast/rust-ast.cc (ExternalFunctionItem::as_string): Likewise.
	(ExternalFunctionItem::accept_vis): Likewise.
	* checks/errors/rust-ast-validation.cc (ASTValidation::visit):
	Likewise.
	* checks/errors/rust-ast-validation.h: Likewise.
	* checks/errors/rust-feature-gate.h: Likewise.
	* expand/rust-cfg-strip.cc (CfgStrip::visit):
	Likewise.
	* expand/rust-cfg-strip.h: Likewise.
	* expand/rust-derive.h: Likewise.
	* expand/rust-expand-visitor.cc (ExpandVisitor::visit):
	Likewise.
	* expand/rust-expand-visitor.h: Likewise.
	* hir/rust-ast-lower-base.cc (ASTLoweringBase::visit):
	Likewise.
	* hir/rust-ast-lower-base.h: Likewise.
	* metadata/rust-export-metadata.cc (ExportContext::emit_function):
	Likewise.
	* parse/rust-parse-impl.h: Likewise.
	* parse/rust-parse.h: Likewise.
	* resolve/rust-ast-resolve-base.cc (ResolverBase::visit):
	Likewise.
	* resolve/rust-ast-resolve-base.h: Likewise.
	* resolve/rust-default-resolver.cc (DefaultResolver::visit):
	Likewise.
	* resolve/rust-default-resolver.h: Likewise.
	* util/rust-attributes.cc (AttributeChecker::visit): Likewise.
	* util/rust-attributes.h: Likewise.

gcc/testsuite/ChangeLog:

	* rust/compile/extern_func_with_body.rs: New test.

Signed-off-by: 0xn4utilus <gyanendrabanjare8@gmail.com>

Author: 0xn4utilus

gcc/rust/ast/rust-ast-collector.cc

@@ -2084,31 +2084,6 @@ TokenCollector::visit (ExternalStaticItem &item)
   push (Rust::Token::make (SEMICOLON, UNDEF_LOCATION));
 }
 
-void
-TokenCollector::visit (ExternalFunctionItem &function)
-{
-  visit_items_as_lines (function.get_outer_attrs ());
-  visit (function.get_visibility ());
-
-  auto id = function.get_identifier ().as_string ();
-
-  push (Rust::Token::make (FN_KW, function.get_locus ()));
-  push (Rust::Token::make_identifier (UNDEF_LOCATION, std::move (id)));
-  if (function.has_generics ())
-    visit (function.get_generic_params ());
-  push (Rust::Token::make (LEFT_PAREN, UNDEF_LOCATION));
-
-  visit_items_joined_by_separator (function.get_function_params ());
-
-  push (Rust::Token::make (RIGHT_PAREN, UNDEF_LOCATION));
-  if (function.has_return_type ())
-    {
-      push (Rust::Token::make (RETURN_TYPE, UNDEF_LOCATION));
-      visit (function.get_return_type ());
-    }
-  push (Rust::Token::make (SEMICOLON, UNDEF_LOCATION));
-}
-
 void
 TokenCollector::visit (ExternBlock &block)
 {

gcc/rust/ast/rust-ast-collector.h

@@ -333,7 +333,6 @@ class TokenCollector : public ASTVisitor
   void visit (TraitImpl &impl);
   void visit (ExternalTypeItem &item);
   void visit (ExternalStaticItem &item);
-  void visit (ExternalFunctionItem &item);
   void visit (ExternBlock &block);
 
   // rust-macro.h

gcc/rust/ast/rust-ast-full-decls.h

@@ -203,7 +203,6 @@ class ExternalItem;
 class ExternalTypeItem;
 class ExternalStaticItem;
 class NamedFunctionParam;
-class ExternalFunctionItem;
 class ExternBlock;
 
 // rust-macro.h

gcc/rust/ast/rust-ast-visitor.cc

@@ -1004,24 +1004,6 @@ DefaultASTVisitor::visit (AST::NamedFunctionParam &param)
     visit (param.get_type ());
 }
 
-void
-DefaultASTVisitor::visit (AST::ExternalFunctionItem &item)
-{
-  visit_outer_attrs (item);
-  visit (item.get_visibility ());
-  for (auto &generic : item.get_generic_params ())
-    visit (generic);
-
-  if (item.has_where_clause ())
-    visit (item.get_where_clause ());
-
-  for (auto &param : item.get_function_params ())
-    visit (param);
-
-  if (item.has_return_type ())
-    visit (item.get_return_type ());
-}
-
 void
 DefaultASTVisitor::visit (AST::ExternBlock &block)
 {

gcc/rust/ast/rust-ast-visitor.h

@@ -164,7 +164,6 @@ class ASTVisitor
   // virtual void visit(ExternalItem& item) = 0;
   virtual void visit (ExternalTypeItem &type) = 0;
   virtual void visit (ExternalStaticItem &item) = 0;
-  virtual void visit (ExternalFunctionItem &item) = 0;
   virtual void visit (ExternBlock &block) = 0;
 
   // rust-macro.h
@@ -338,7 +337,6 @@ class DefaultASTVisitor : public ASTVisitor
   virtual void visit (AST::TraitImpl &impl) override;
   virtual void visit (AST::ExternalTypeItem &item) override;
   virtual void visit (AST::ExternalStaticItem &item) override;
-  virtual void visit (AST::ExternalFunctionItem &item) override;
   virtual void visit (AST::ExternBlock &block) override;
   virtual void visit (AST::MacroMatchFragment &match) override;
   virtual void visit (AST::MacroMatchRepetition &match) override;

gcc/rust/ast/rust-ast.cc

@@ -2974,69 +2974,6 @@ ExternalStaticItem::as_string () const
   return str;
 }
 
-std::string
-ExternalFunctionItem::as_string () const
-{
-  // outer attributes
-  std::string str = append_attributes (outer_attrs, OUTER);
-
-  // start visibility on new line and with a space
-  str += "\n" + visibility.as_string () + " ";
-
-  str += "fn ";
-
-  // add name
-  str += item_name.as_string ();
-
-  // generic params
-  str += "\n Generic params: ";
-  if (generic_params.empty ())
-    {
-      str += "none";
-    }
-  else
-    {
-      for (const auto &param : generic_params)
-	{
-	  // DEBUG: null pointer check
-	  if (param == nullptr)
-	    {
-	      rust_debug (
-		"something really terrible has gone wrong - null pointer "
-		"generic param in external function item.");
-	      return "NULL_POINTER_MARK";
-	    }
-
-	  str += "\n  " + param->as_string ();
-	}
-    }
-
-  // function params
-  str += "\n Function params: ";
-  if (function_params.empty ())
-    {
-      str += "none";
-    }
-  else
-    {
-      for (const auto &param : function_params)
-	str += "\n  " + param.as_string ();
-    }
-
-  // add type on new line
-  str += "\n (return) Type: "
-	 + (has_return_type () ? return_type->as_string () : "()");
-
-  // where clause
-  str += "\n Where clause: ";
-  if (has_where_clause ())
-    str += where_clause.as_string ();
-  else
-    str += "none";
-
-  return str;
-}
-
 std::string
 NamedFunctionParam::as_string () const
 {
@@ -4866,12 +4803,6 @@ ExternalStaticItem::accept_vis (ASTVisitor &vis)
   vis.visit (*this);
 }
 
-void
-ExternalFunctionItem::accept_vis (ASTVisitor &vis)
-{
-  vis.visit (*this);
-}
-
 void
 ExternBlock::accept_vis (ASTVisitor &vis)
 {

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

@@ -64,25 +64,6 @@ ASTValidation::visit (AST::ConstantItem &const_item)
   AST::ContextualASTVisitor::visit (const_item);
 }
 
-void
-ASTValidation::visit (AST::ExternalFunctionItem &item)
-{
-  auto &params = item.get_function_params ();
-
-  if (params.size () == 1 && params[0].is_variadic ())
-    rust_error_at (
-      params[0].get_locus (),
-      "C-variadic function must be declared with at least one named argument");
-
-  for (auto it = params.begin (); it != params.end (); it++)
-    if (it->is_variadic () && it + 1 != params.end ())
-      rust_error_at (
-	it->get_locus (),
-	"%<...%> must be the last argument of a C-variadic function");
-
-  AST::ContextualASTVisitor::visit (item);
-}
-
 void
 ASTValidation::visit (AST::Union &item)
 {

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

@@ -38,7 +38,6 @@ class ASTValidation : public AST::ContextualASTVisitor
   virtual void visit (AST::ConstantItem &const_item);
   virtual void visit (AST::Lifetime &lifetime);
   virtual void visit (AST::LoopLabel &label);
-  virtual void visit (AST::ExternalFunctionItem &item);
   virtual void visit (AST::Union &item);
   virtual void visit (AST::Function &function);
   virtual void visit (AST::Trait &trait);

gcc/rust/checks/errors/rust-feature-gate.h

@@ -130,7 +130,6 @@ class FeatureGate : public AST::DefaultASTVisitor
   void visit (AST::Trait &trait) override {}
   void visit (AST::ExternalTypeItem &item) override;
   void visit (AST::ExternalStaticItem &item) override {}
-  void visit (AST::ExternalFunctionItem &item) override {}
   void visit (AST::ExternBlock &block) override;
   void visit (AST::MacroMatchFragment &match) override {}
   void visit (AST::MacroMatchRepetition &match) override {}

gcc/rust/expand/rust-cfg-strip.cc

@@ -2195,62 +2195,6 @@ CfgStrip::visit (AST::ExternalStaticItem &item)
     rust_error_at (type->get_locus (), "cannot strip type in this position");
 }
 
-void
-CfgStrip::visit (AST::ExternalFunctionItem &item)
-{
-  // strip test based on outer attrs
-  expand_cfg_attrs (item.get_outer_attrs ());
-  if (fails_cfg_with_expand (item.get_outer_attrs ()))
-    {
-      item.mark_for_strip ();
-      return;
-    }
-
-  AST::DefaultASTVisitor::visit (item);
-
-  /* strip function parameters if required - this is specifically
-   * allowed by spec */
-  auto &params = item.get_function_params ();
-  for (auto it = params.begin (); it != params.end ();)
-    {
-      auto &param = *it;
-
-      auto &param_attrs = param.get_outer_attrs ();
-      expand_cfg_attrs (param_attrs);
-      if (fails_cfg_with_expand (param_attrs))
-	{
-	  it = params.erase (it);
-	  continue;
-	}
-
-      if (!param.is_variadic ())
-	{
-	  auto &type = param.get_type ();
-	  if (type->is_marked_for_strip ())
-	    rust_error_at (type->get_locus (),
-			   "cannot strip type in this position");
-	}
-
-      // increment if nothing else happens
-      ++it;
-    }
-  /* NOTE: these are extern function params, which may have different
-   * rules and restrictions to "normal" function params. So expansion
-   * handled separately. */
-
-  /* TODO: assuming that variadic nature cannot be stripped. If this
-   * is not true, then have code here to do so. */
-
-  if (item.has_return_type ())
-    {
-      auto &return_type = item.get_return_type ();
-
-      if (return_type->is_marked_for_strip ())
-	rust_error_at (return_type->get_locus (),
-		       "cannot strip type in this position");
-    }
-}
-
 void
 CfgStrip::visit (AST::ExternBlock &block)
 {

gcc/rust/expand/rust-cfg-strip.h

@@ -150,7 +150,6 @@ class CfgStrip : public AST::DefaultASTVisitor
   void visit (AST::TraitImpl &impl) override;
   void visit (AST::ExternalTypeItem &item) override;
   void visit (AST::ExternalStaticItem &item) override;
-  void visit (AST::ExternalFunctionItem &item) override;
   void visit (AST::ExternBlock &block) override;
 
   // I don't think it would be possible to strip macros without expansion

gcc/rust/expand/rust-derive.h

@@ -166,7 +166,6 @@ class DeriveVisitor : public AST::ASTVisitor
   virtual void visit (TraitImpl &impl) override final{};
   virtual void visit (ExternalTypeItem &type) override final{};
   virtual void visit (ExternalStaticItem &item) override final{};
-  virtual void visit (ExternalFunctionItem &item) override final{};
   virtual void visit (ExternBlock &block) override final{};
   virtual void visit (MacroMatchFragment &match) override final{};
   virtual void visit (MacroMatchRepetition &match) override final{};

gcc/rust/expand/rust-expand-visitor.cc

@@ -922,23 +922,6 @@ ExpandVisitor::visit (AST::ExternalStaticItem &static_item)
   maybe_expand_type (static_item.get_type ());
 }
 
-void
-ExpandVisitor::visit (AST::ExternalFunctionItem &item)
-{
-  for (auto &param : item.get_generic_params ())
-    visit (param);
-
-  for (auto &param : item.get_function_params ())
-    if (!param.is_variadic ())
-      maybe_expand_type (param.get_type ());
-
-  if (item.has_return_type ())
-    maybe_expand_type (item.get_return_type ());
-
-  if (item.has_where_clause ())
-    expand_where_clause (item.get_where_clause ());
-}
-
 void
 ExpandVisitor::visit (AST::ExternBlock &block)
 {

gcc/rust/expand/rust-expand-visitor.h

@@ -252,7 +252,6 @@ class ExpandVisitor : public AST::DefaultASTVisitor
   void visit (AST::TraitImpl &impl) override;
   void visit (AST::ExternalTypeItem &item) override;
   void visit (AST::ExternalStaticItem &item) override;
-  void visit (AST::ExternalFunctionItem &item) override;
   void visit (AST::ExternBlock &block) override;
 
   // I don't think it would be possible to strip macros without expansion

gcc/rust/hir/rust-ast-lower-base.cc

@@ -345,9 +345,6 @@ void
 ASTLoweringBase::visit (AST::ExternalStaticItem &)
 {}
 void
-ASTLoweringBase::visit (AST::ExternalFunctionItem &)
-{}
-void
 ASTLoweringBase::visit (AST::ExternBlock &)
 {}
 

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

@@ -186,7 +186,6 @@ class ASTLoweringBase : public AST::ASTVisitor
   //  virtual void visit(ExternalItem& item);
   virtual void visit (AST::ExternalTypeItem &item);
   virtual void visit (AST::ExternalStaticItem &item);
-  virtual void visit (AST::ExternalFunctionItem &item);
   virtual void visit (AST::ExternBlock &block);
 
   // rust-macro.h

gcc/rust/metadata/rust-export-metadata.cc

@@ -93,46 +93,9 @@ ExportContext::emit_function (const HIR::Function &fn)
       // FIXME assert that this is actually an AST::Function
       AST::Function &function = static_cast<AST::Function &> (vis_item);
 
-      // we can emit an extern block with abi of "rust"
-      Identifier item_name = function.get_function_name ();
-
-      // always empty for extern linkage
-      AST::WhereClause where_clause = AST::WhereClause::create_empty ();
-      std::vector<std::unique_ptr<AST::GenericParam>> generic_params;
-
-      AST::Visibility vis = function.get_visibility ();
-      std::unique_ptr<AST::Type> return_type
-	= std::unique_ptr<AST::Type> (nullptr);
-      if (function.has_return_type ())
-	{
-	  return_type = function.get_return_type ()->clone_type ();
-	}
-
-      std::vector<AST::NamedFunctionParam> function_params;
-      for (auto &p : function.get_function_params ())
-	{
-	  if (p->is_variadic () || p->is_self ())
-	    rust_unreachable ();
-	  auto param = static_cast<AST::FunctionParam *> (p.get ());
-	  std::string name = param->get_pattern ()->as_string ();
-	  std::unique_ptr<AST::Type> param_type
-	    = param->get_type ()->clone_type ();
-
-	  AST::NamedFunctionParam np (name, std::move (param_type), {},
-				      param->get_locus ());
-	  function_params.push_back (std::move (np));
-	}
-
-      AST::ExternalItem *external_item
-	= new AST::ExternalFunctionItem (item_name, {} /* generic_params */,
-					 std::move (return_type), where_clause,
-					 std::move (function_params), vis,
-					 function.get_outer_attrs (),
-					 function.get_locus ());
-
       std::vector<std::unique_ptr<AST::ExternalItem>> external_items;
-      external_items.push_back (
-	std::unique_ptr<AST::ExternalItem> (external_item));
+      external_items.push_back (std::unique_ptr<AST::ExternalItem> (
+	static_cast<AST::ExternalItem *> (&function)));
 
       AST::ExternBlock extern_block (get_string_from_abi (Rust::ABI::RUST),
 				     std::move (external_items),