Merge #540

540: Add trait-impl support for methods r=philberty a=philberty

This PR strips HIR::Method and reuses the HIR::Function with a HIR::SelfParam.
It reduces complexity in type checking and GENERIC generation.

Co-authored-by: Philip Herron <philip.herron@embecosm.com>

2 files changed, 38 insertions, 203 deletions

diff --git a/gcc/rust/backend/rust-compile-base.h b/gcc/rust/backend/rust-compile-base.h
index c346af5..6a05c1c 100644
--- a/gcc/rust/backend/rust-compile-base.h
+++ b/gcc/rust/backend/rust-compile-base.h
@@ -121,7 +121,6 @@ public:
   // virtual void visit(WhereClauseItem& item) {}
   virtual void visit (HIR::LifetimeWhereClauseItem &item) {}
   virtual void visit (HIR::TypeBoundWhereClauseItem &item) {}
-  virtual void visit (HIR::Method &method) {}
   virtual void visit (HIR::ModuleBodied &module) {}
   virtual void visit (HIR::ModuleNoBody &module) {}
   virtual void visit (HIR::ExternCrate &crate) {}
diff --git a/gcc/rust/backend/rust-compile-implitem.h b/gcc/rust/backend/rust-compile-implitem.h
index 70f76b7..83af5de 100644
--- a/gcc/rust/backend/rust-compile-implitem.h
+++ b/gcc/rust/backend/rust-compile-implitem.h
@@ -135,212 +135,48 @@ public:
     TyTy::BaseType *tyret = fntype->get_return_type ();
     std::vector<Bvariable *> param_vars;
 
-    size_t i = 0;
-    for (auto &it : fntype->get_params ())
+    if (function.is_method ())
       {
-	HIR::FunctionParam &referenced_param
-	  = function.get_function_params ().at (i);
-	auto param_tyty = it.second;
-	auto compiled_param_type
-	  = TyTyResolveCompile::compile (ctx, param_tyty);
-
-	Location param_locus
-	  = ctx->get_mappings ()->lookup_location (param_tyty->get_ref ());
-	Bvariable *compiled_param_var
-	  = CompileFnParam::compile (ctx, fndecl, &referenced_param,
-				     compiled_param_type, param_locus);
-	if (compiled_param_var == nullptr)
+	// insert self
+	TyTy::BaseType *self_tyty_lookup = nullptr;
+	if (!ctx->get_tyctx ()->lookup_type (
+	      function.get_self_param ().get_mappings ().get_hirid (),
+	      &self_tyty_lookup))
 	  {
-	    rust_error_at (param_locus, "failed to compile parameter variable");
+	    rust_error_at (function.get_self_param ().get_locus (),
+			   "failed to lookup self param type");
 	    return;
 	  }
 
-	param_vars.push_back (compiled_param_var);
-
-	ctx->insert_var_decl (referenced_param.get_mappings ().get_hirid (),
-			      compiled_param_var);
-	i++;
-      }
-
-    if (!ctx->get_backend ()->function_set_parameters (fndecl, param_vars))
-      {
-	rust_fatal_error (function.get_locus (),
-			  "failed to setup parameter variables");
-	return;
-      }
-
-    // lookup locals
-    auto block_expr = function.get_definition ().get ();
-    auto body_mappings = block_expr->get_mappings ();
-
-    Resolver::Rib *rib = nullptr;
-    if (!ctx->get_resolver ()->find_name_rib (body_mappings.get_nodeid (),
-					      &rib))
-      {
-	rust_fatal_error (function.get_locus (),
-			  "failed to setup locals per block");
-	return;
-      }
-
-    std::vector<Bvariable *> locals;
-    bool ok = compile_locals_for_block (*rib, fndecl, locals);
-    rust_assert (ok);
-
-    Bblock *enclosing_scope = NULL;
-    HIR::BlockExpr *function_body = function.get_definition ().get ();
-    Location start_location = function_body->get_locus ();
-    Location end_location = function_body->get_closing_locus ();
-
-    Bblock *code_block
-      = ctx->get_backend ()->block (fndecl, enclosing_scope, locals,
-				    start_location, end_location);
-    ctx->push_block (code_block);
-
-    Bvariable *return_address = nullptr;
-    if (function.has_function_return_type ())
-      {
-	Btype *return_type = TyTyResolveCompile::compile (ctx, tyret);
-
-	bool address_is_taken = false;
-	Bstatement *ret_var_stmt = nullptr;
-
-	return_address = ctx->get_backend ()->temporary_variable (
-	  fndecl, code_block, return_type, NULL, address_is_taken,
-	  function.get_locus (), &ret_var_stmt);
-
-	ctx->add_statement (ret_var_stmt);
-      }
-
-    ctx->push_fn (fndecl, return_address);
-
-    compile_function_body (fndecl, function.get_definition (),
-			   function.has_function_return_type ());
-
-    ctx->pop_block ();
-    auto body = ctx->get_backend ()->block_statement (code_block);
-    if (!ctx->get_backend ()->function_set_body (fndecl, body))
-      {
-	rust_error_at (function.get_locus (), "failed to set body to function");
-	return;
-      }
-
-    ctx->pop_fn ();
-
-    ctx->push_function (fndecl);
-  }
-
-  void visit (HIR::Method &method) override
-  {
-    if (!compile_fns)
-      return;
-
-    TyTy::BaseType *fntype_tyty;
-    if (!ctx->get_tyctx ()->lookup_type (method.get_mappings ().get_hirid (),
-					 &fntype_tyty))
-      {
-	rust_fatal_error (method.get_locus (),
-			  "failed to lookup function type");
-	return;
-      }
-
-    rust_assert (fntype_tyty->get_kind () == TyTy::TypeKind::FNDEF);
-    TyTy::FnType *fntype = static_cast<TyTy::FnType *> (fntype_tyty);
-    if (fntype->has_subsititions_defined ())
-      {
-	// we cant do anything for this only when it is used and a concrete type
-	// is given
-	if (concrete == nullptr)
-	  return;
-	else
+	Btype *self_type = TyTyResolveCompile::compile (ctx, self_tyty_lookup);
+	if (self_type == nullptr)
 	  {
-	    rust_assert (concrete->get_kind () == TyTy::TypeKind::FNDEF);
-	    fntype = static_cast<TyTy::FnType *> (concrete);
+	    rust_error_at (function.get_self_param ().get_locus (),
+			   "failed to compile self param type");
+	    return;
 	  }
-      }
 
-    // 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.
-    Bfunction *lookup = nullptr;
-    if (ctx->lookup_function_decl (fntype->get_ty_ref (), &lookup, fntype))
-      {
-	// has this been added to the list then it must be finished
-	if (ctx->function_completed (lookup))
+	Bvariable *compiled_self_param
+	  = CompileSelfParam::compile (ctx, fndecl, function.get_self_param (),
+				       self_type,
+				       function.get_self_param ().get_locus ());
+	if (compiled_self_param == nullptr)
 	  {
-	    Bfunction *dummy = nullptr;
-	    if (!ctx->lookup_function_decl (fntype->get_ty_ref (), &dummy))
-	      ctx->insert_function_decl (fntype->get_ty_ref (), lookup, fntype);
-
+	    rust_error_at (function.get_self_param ().get_locus (),
+			   "failed to compile self param variable");
 	    return;
 	  }
-      }
-
-    if (fntype->has_subsititions_defined ())
-      {
-	// override the Hir Lookups for the substituions in this context
-	fntype->override_context ();
-      }
-
-    // convert to the actual function type
-    ::Btype *compiled_fn_type = TyTyResolveCompile::compile (ctx, fntype);
-
-    unsigned int flags = 0;
-
-    // if its the main fn or pub visibility mark its as DECL_PUBLIC
-    // please see https://github.com/Rust-GCC/gccrs/pull/137
-    if (method.has_visibility ())
-      flags |= Backend::function_is_visible;
-
-    std::string fn_identifier
-      = self->get_name () + "_" + method.get_method_name ();
-    std::string asm_name
-      = ctx->mangle_impl_item (self, fntype, method.get_method_name ());
-
-    Bfunction *fndecl
-      = ctx->get_backend ()->function (compiled_fn_type, fn_identifier,
-				       asm_name, flags, method.get_locus ());
-    ctx->insert_function_decl (fntype->get_ty_ref (), fndecl, fntype);
-
-    // setup the params
-    TyTy::BaseType *tyret = fntype->get_return_type ();
-    std::vector<Bvariable *> param_vars;
 
-    // insert self
-    TyTy::BaseType *self_tyty_lookup = nullptr;
-    if (!ctx->get_tyctx ()->lookup_type (
-	  method.get_self_param ().get_mappings ().get_hirid (),
-	  &self_tyty_lookup))
-      {
-	rust_error_at (method.get_self_param ().get_locus (),
-		       "failed to lookup self param type");
-	return;
-      }
-
-    Btype *self_type = TyTyResolveCompile::compile (ctx, self_tyty_lookup);
-    if (self_type == nullptr)
-      {
-	rust_error_at (method.get_self_param ().get_locus (),
-		       "failed to compile self param type");
-	return;
-      }
-
-    Bvariable *compiled_self_param
-      = CompileSelfParam::compile (ctx, fndecl, method.get_self_param (),
-				   self_type,
-				   method.get_self_param ().get_locus ());
-    if (compiled_self_param == nullptr)
-      {
-	rust_error_at (method.get_self_param ().get_locus (),
-		       "failed to compile self param variable");
-	return;
+	param_vars.push_back (compiled_self_param);
+	ctx->insert_var_decl (
+	  function.get_self_param ().get_mappings ().get_hirid (),
+	  compiled_self_param);
       }
 
-    param_vars.push_back (compiled_self_param);
-    ctx->insert_var_decl (method.get_self_param ().get_mappings ().get_hirid (),
-			  compiled_self_param);
-
-    // offset from + 1 for the TyTy::FnType being used
-    size_t i = 1;
-    for (auto referenced_param : method.get_function_params ())
+    // offset from + 1 for the TyTy::FnType being used when this is a method to
+    // skip over Self on the FnType
+    size_t i = function.is_method () ? 1 : 0;
+    for (auto referenced_param : function.get_function_params ())
       {
 	auto tyty_param = fntype->param_at (i);
 	auto param_tyty = tyty_param.second;
@@ -361,7 +197,7 @@ public:
 				     compiled_param_type, param_locus);
 	if (compiled_param_var == nullptr)
 	  {
-	    rust_error_at (param_locus, "failed to compile parameter variable");
+	    rust_error_at (param_locus, "Failed to compile parameter variable");
 	    return;
 	  }
 
@@ -374,20 +210,20 @@ public:
 
     if (!ctx->get_backend ()->function_set_parameters (fndecl, param_vars))
       {
-	rust_fatal_error (method.get_locus (),
+	rust_fatal_error (function.get_locus (),
 			  "failed to setup parameter variables");
 	return;
       }
 
     // lookup locals
-    auto block_expr = method.get_function_body ().get ();
+    auto block_expr = function.get_definition ().get ();
     auto body_mappings = block_expr->get_mappings ();
 
     Resolver::Rib *rib = nullptr;
     if (!ctx->get_resolver ()->find_name_rib (body_mappings.get_nodeid (),
 					      &rib))
       {
-	rust_fatal_error (method.get_locus (),
+	rust_fatal_error (function.get_locus (),
 			  "failed to setup locals per block");
 	return;
       }
@@ -397,7 +233,7 @@ public:
     rust_assert (ok);
 
     Bblock *enclosing_scope = NULL;
-    HIR::BlockExpr *function_body = method.get_function_body ().get ();
+    HIR::BlockExpr *function_body = function.get_definition ().get ();
     Location start_location = function_body->get_locus ();
     Location end_location = function_body->get_closing_locus ();
 
@@ -407,7 +243,7 @@ public:
     ctx->push_block (code_block);
 
     Bvariable *return_address = nullptr;
-    if (method.has_function_return_type ())
+    if (function.has_function_return_type ())
       {
 	Btype *return_type = TyTyResolveCompile::compile (ctx, tyret);
 
@@ -416,21 +252,21 @@ public:
 
 	return_address = ctx->get_backend ()->temporary_variable (
 	  fndecl, code_block, return_type, NULL, address_is_taken,
-	  method.get_locus (), &ret_var_stmt);
+	  function.get_locus (), &ret_var_stmt);
 
 	ctx->add_statement (ret_var_stmt);
       }
 
     ctx->push_fn (fndecl, return_address);
 
-    compile_function_body (fndecl, method.get_function_body (),
-			   method.has_function_return_type ());
+    compile_function_body (fndecl, function.get_definition (),
+			   function.has_function_return_type ());
 
     ctx->pop_block ();
     auto body = ctx->get_backend ()->block_statement (code_block);
     if (!ctx->get_backend ()->function_set_body (fndecl, body))
       {
-	rust_error_at (method.get_locus (), "failed to set body to function");
+	rust_error_at (function.get_locus (), "failed to set body to function");
 	return;
       }