mangle/link_name fixes

Author: powerboat9

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

@@ -34,6 +34,7 @@
 #include "rust-attribute-values.h"
 #include "rust-attributes.h"
 #include "rust-immutable-name-resolution-context.h"
+#include "rust-ggc.h"
 
 #include "fold-const.h"
 #include "stringpool.h"
@@ -47,11 +48,43 @@
 namespace Rust {
 namespace Compile {
 
-bool inline should_mangle_item (const tree fndecl)
+tl::optional<GGC::Ident> inline get_unmangled_name (const std::string &function_name, const AST::AttrVec &attrs)
 {
-  return lookup_attribute (Values::Attributes::NO_MANGLE,
-			   DECL_ATTRIBUTES (fndecl))
-	 == NULL_TREE;
+  tl::optional<GGC::Ident> set_name;
+  for (auto &attr : attrs)
+    {
+      auto name = attr.get_path ().as_string ();
+      if (name == Values::Attributes::NO_MANGLE)
+        {
+	  // TODO: better errors
+	  rust_assert (!set_name.has_value ());
+	  set_name = function_name;
+  
+  if (attr.has_attr_input ())
+    {
+      rust_error_at (attr.get_locus (),
+		     "attribute %<no_mangle%> does not accept any arguments");
+    }
+
+	}
+      else if (name == Values::Attributes::LINK_NAME)
+        {
+	  // TODO: better errors
+	  rust_assert (!set_name.has_value ());
+
+	  rust_assert (attr.has_attr_input ());
+	  auto &input = attr.get_attr_input ();
+
+	  rust_assert (input.get_attr_input_type () == AST::AttrInput::AttrInputType::LITERAL);
+	  auto &literal = static_cast<AST::AttrInputLiteral &> (input).get_literal ();
+	  
+	  rust_assert (literal.get_lit_type () == AST::Literal::LitType::STRING || literal.get_lit_type () == AST::Literal::LitType::RAW_STRING);
+	  // TODO: special handling for STRING/RAW_STRING?
+	  set_name = literal.as_string ();
+	}
+    }
+
+  return set_name;
 }
 
 void
@@ -85,8 +118,6 @@ HIRCompileBase::setup_fndecl (tree fndecl, bool is_main_entry_point,
       bool is_cold = attr.get_path ().as_string () == Values::Attributes::COLD;
       bool is_link_section
 	= attr.get_path ().as_string () == Values::Attributes::LINK_SECTION;
-      bool no_mangle
-	= attr.get_path ().as_string () == Values::Attributes::NO_MANGLE;
       bool is_deprecated
 	= attr.get_path ().as_string () == Values::Attributes::DEPRECATED;
       bool is_proc_macro
@@ -117,10 +148,6 @@ HIRCompileBase::setup_fndecl (tree fndecl, bool is_main_entry_point,
 	{
 	  handle_deprecated_attribute_on_fndecl (fndecl, attr);
 	}
-      else if (no_mangle)
-	{
-	  handle_no_mangle_attribute_on_fndecl (fndecl, attr);
-	}
       else if (is_proc_macro)
 	{
 	  handle_bang_proc_macro_attribute_on_fndecl (fndecl, attr);
@@ -269,22 +296,6 @@ HIRCompileBase::handle_link_section_attribute_on_fndecl (
   set_decl_section_name (fndecl, msg_str->c_str ());
 }
 
-void
-HIRCompileBase::handle_no_mangle_attribute_on_fndecl (
-  tree fndecl, const AST::Attribute &attr)
-{
-  if (attr.has_attr_input ())
-    {
-      rust_error_at (attr.get_locus (),
-		     "attribute %<no_mangle%> does not accept any arguments");
-      return;
-    }
-
-  DECL_ATTRIBUTES (fndecl)
-    = tree_cons (get_identifier (Values::Attributes::NO_MANGLE), NULL_TREE,
-		 DECL_ATTRIBUTES (fndecl));
-}
-
 void
 HIRCompileBase::handle_deprecated_attribute_on_fndecl (
   tree fndecl, const AST::Attribute &attr)
@@ -702,7 +713,6 @@ HIRCompileBase::compile_function (
       /* So that 'MAIN_NAME_P' works.  */
       main_identifier_node = get_identifier (ir_symbol_name.c_str ());
     }
-  std::string asm_name = fn_name;
 
   unsigned int flags = 0;
   tree fndecl = Backend::function (compiled_fn_type, ir_symbol_name,
@@ -713,12 +723,10 @@ HIRCompileBase::compile_function (
   setup_abi_options (fndecl, get_abi (outer_attrs, qualifiers));
 
   // conditionally mangle the function name
-  bool should_mangle = should_mangle_item (fndecl);
-  if (!is_main_fn && should_mangle)
-    asm_name = ctx->mangle_item (fntype, canonical_path);
-  SET_DECL_ASSEMBLER_NAME (fndecl,
-			   get_identifier_with_length (asm_name.data (),
-						       asm_name.length ()));
+  auto unmangled = is_main_fn ? "main" : get_unmangled_name (fn_name, outer_attrs);
+  GGC::Ident asm_name = unmangled ? *unmangled : ctx->mangle_item (fntype, canonical_path);
+
+  SET_DECL_ASSEMBLER_NAME (fndecl, asm_name.as_tree ());
 
   // insert into the context
   ctx->insert_function_decl (fntype, fndecl);

gcc/rust/util/rust-attribute-values.h

@@ -37,6 +37,7 @@ class Attributes
   static constexpr auto &MUST_USE = "must_use";
   static constexpr auto &LANG = "lang";
   static constexpr auto &LINK_SECTION = "link_section";
+  static constexpr auto &LINK_NAME = "link_name";
   static constexpr auto &NO_MANGLE = "no_mangle";
   static constexpr auto &REPR = "repr";
   static constexpr auto &RUSTC_BUILTIN_MACRO = "rustc_builtin_macro";

gcc/rust/util/rust-attributes.cc

@@ -79,6 +79,7 @@ static const BuiltinAttrDefinition __definitions[]
      {Attrs::MUST_USE, STATIC_ANALYSIS},
      {Attrs::LANG, HIR_LOWERING},
      {Attrs::LINK_SECTION, CODE_GENERATION},
+     {Attrs::LINK_NAME, CODE_GENERATION},
      {Attrs::NO_MANGLE, CODE_GENERATION},
      {Attrs::REPR, CODE_GENERATION},
      {Attrs::RUSTC_BUILTIN_MACRO, EXPANSION},