[gcc/devel/rust/master] backend: handle deprecated attribute

[gcc/devel/rust/master] backend: handle deprecated attribute

[Thomas Schwinge]

https://gcc.gnu.org/g:04cc46cfe8cad9736ccf2d5c884af50e57b67ce6

commit 04cc46cfe8cad9736ccf2d5c884af50e57b67ce6
Author: liushuyu <liushuyu011@gmail.com>
Date:   Thu Apr 21 18:21:10 2022 -0600

    backend: handle deprecated attribute
    
    Signed-off-by: Zixing Liu <liushuyu011@gmail.com>

Diff:
---
 gcc/rust/ast/rust-ast-full-test.cc    |  9 ++++-
 gcc/rust/ast/rust-ast.h               |  2 ++
 gcc/rust/ast/rust-macro.h             |  8 +++++
 gcc/rust/backend/rust-compile-base.cc | 68 ++++++++++++++++++++++++++++++++++-
 gcc/rust/backend/rust-compile-base.h  |  3 ++
 gcc/rust/util/rust-attributes.cc      |  1 +
 6 files changed, 89 insertions(+), 2 deletions(-)

diff --git a/gcc/rust/ast/rust-ast-full-test.cc b/gcc/rust/ast/rust-ast-full-test.cc
index 0d4d36b36cc..81791135bc4 100644
--- a/gcc/rust/ast/rust-ast-full-test.cc
+++ b/gcc/rust/ast/rust-ast-full-test.cc
@@ -20,10 +20,12 @@ along with GCC; see the file COPYING3.  If not see
 // FIXME: This does not work on Windows
 #include <string>
 #include <unistd.h>
+#include <memory>
 
 #include "rust-ast-full.h"
 #include "rust-diagnostics.h"
 #include "rust-ast-visitor.h"
+#include "rust-macro.h"
 #include "rust-session-manager.h"
 #include "rust-lex.h"
 #include "rust-parse.h"
@@ -3862,7 +3864,12 @@ MetaItemInner::~MetaItemInner () = default;
 std::unique_ptr<MetaNameValueStr>
 MetaItemInner::to_meta_name_value_str () const
 {
-  // TODO parse foo = bar
+  if (is_key_value_pair ())
+    {
+      auto converted_item = static_cast<const MetaNameValueStr *> (this);
+      return converted_item->to_meta_name_value_str ();
+    }
+  // TODO actually parse foo = bar
   return nullptr;
 }
 
diff --git a/gcc/rust/ast/rust-ast.h b/gcc/rust/ast/rust-ast.h
index 76324dc7304..51fe3c49c59 100644
--- a/gcc/rust/ast/rust-ast.h
+++ b/gcc/rust/ast/rust-ast.h
@@ -645,6 +645,8 @@ public:
   virtual Attribute to_attribute () const { return Attribute::create_empty (); }
 
   virtual bool check_cfg_predicate (const Session &session) const = 0;
+
+  virtual bool is_key_value_pair () const { return false; }
 };
 
 // Container used to store MetaItems as AttrInput (bridge-ish kinda thing)
diff --git a/gcc/rust/ast/rust-macro.h b/gcc/rust/ast/rust-macro.h
index 1bf8912083a..ce515db0aad 100644
--- a/gcc/rust/ast/rust-macro.h
+++ b/gcc/rust/ast/rust-macro.h
@@ -21,6 +21,7 @@
 
 #include "rust-ast.h"
 #include "rust-location.h"
+#include <string>
 
 namespace Rust {
 namespace AST {
@@ -816,6 +817,13 @@ public:
 
   Attribute to_attribute () const override;
 
+  inline std::pair<Identifier, std::string> get_name_value_pair () const
+  {
+    return std::pair<Identifier, std::string> (ident, str);
+  }
+
+  bool is_key_value_pair () const override { return true; }
+
 protected:
   // Use covariance to implement clone function as returning this type
   MetaNameValueStr *clone_meta_item_inner_impl () const override
diff --git a/gcc/rust/backend/rust-compile-base.cc b/gcc/rust/backend/rust-compile-base.cc
index 8fa3fa18793..335a6d411a5 100644
--- a/gcc/rust/backend/rust-compile-base.cc
+++ b/gcc/rust/backend/rust-compile-base.cc
@@ -22,7 +22,8 @@
 #include "rust-compile-fnparam.h"
 #include "rust-compile-var-decl.h"
 
-#include "rust-expr.h" // for AST::AttrInputLiteral
+#include "rust-expr.h"	// for AST::AttrInputLiteral
+#include "rust-macro.h" // for AST::MetaNameValueStr
 
 #include "fold-const.h"
 #include "stringpool.h"
@@ -66,6 +67,9 @@ HIRCompileBase::setup_fndecl (tree fndecl, bool is_main_entry_point,
       bool is_link_section
 	= attr.get_path ().as_string ().compare ("link_section") == 0;
       bool no_mangle = attr.get_path ().as_string ().compare ("no_mangle") == 0;
+      bool is_deprecated
+	= attr.get_path ().as_string ().compare ("deprecated") == 0;
+
       if (is_inline)
 	{
 	  handle_inline_attribute_on_fndecl (fndecl, attr);
@@ -82,6 +86,10 @@ HIRCompileBase::setup_fndecl (tree fndecl, bool is_main_entry_point,
 	{
 	  handle_link_section_attribute_on_fndecl (fndecl, attr);
 	}
+      else if (is_deprecated)
+	{
+	  handle_deprecated_attribute_on_fndecl (fndecl, attr);
+	}
       else if (no_mangle)
 	{
 	  handle_no_mangle_attribute_on_fndecl (fndecl, attr);
@@ -147,6 +155,64 @@ HIRCompileBase::handle_no_mangle_attribute_on_fndecl (
 					DECL_ATTRIBUTES (fndecl));
 }
 
+void
+HIRCompileBase::handle_deprecated_attribute_on_fndecl (
+  tree fndecl, const AST::Attribute &attr)
+{
+  tree value = NULL_TREE;
+  TREE_DEPRECATED (fndecl) = 1;
+
+  // simple #[deprecated]
+  if (!attr.has_attr_input ())
+    return;
+
+  const AST::AttrInput &input = attr.get_attr_input ();
+  auto input_type = input.get_attr_input_type ();
+
+  if (input_type == AST::AttrInput::AttrInputType::LITERAL)
+    {
+      // handle #[deprecated = "message"]
+      auto &literal
+	= static_cast<AST::AttrInputLiteral &> (attr.get_attr_input ());
+      const auto &msg_str = literal.get_literal ().as_string ();
+      value = build_string (msg_str.size (), msg_str.c_str ());
+    }
+  else if (input_type == AST::AttrInput::AttrInputType::TOKEN_TREE)
+    {
+      // handle #[deprecated(since = "...", note = "...")]
+      const auto &option = static_cast<const AST::DelimTokenTree &> (input);
+      AST::AttrInputMetaItemContainer *meta_item = option.parse_to_meta_item ();
+      for (const auto &item : meta_item->get_items ())
+	{
+	  auto converted_item = item->to_meta_name_value_str ();
+	  if (!converted_item)
+	    continue;
+	  auto key_value = converted_item->get_name_value_pair ();
+	  if (key_value.first.compare ("since") == 0)
+	    {
+	      // valid, but this is handled by Cargo and some third-party audit
+	      // tools
+	      continue;
+	    }
+	  else if (key_value.first.compare ("note") == 0)
+	    {
+	      const auto &msg_str = key_value.second;
+	      if (value)
+		rust_error_at (attr.get_locus (), "multiple %<note%> items");
+	      value = build_string (msg_str.size (), msg_str.c_str ());
+	    }
+	  else
+	    {
+	      rust_error_at (attr.get_locus (), "unknown meta item %qs",
+			     key_value.first.c_str ());
+	    }
+	}
+    }
+
+  DECL_ATTRIBUTES (fndecl) = tree_cons (get_identifier ("deprecated"), value,
+					DECL_ATTRIBUTES (fndecl));
+}
+
 void
 HIRCompileBase::handle_inline_attribute_on_fndecl (tree fndecl,
 						   const AST::Attribute &attr)
diff --git a/gcc/rust/backend/rust-compile-base.h b/gcc/rust/backend/rust-compile-base.h
index 52e0568c88e..f993d06cb33 100644
--- a/gcc/rust/backend/rust-compile-base.h
+++ b/gcc/rust/backend/rust-compile-base.h
@@ -92,6 +92,9 @@ protected:
   static void
   handle_link_section_attribute_on_fndecl (tree fndecl,
 					   const AST::Attribute &attr);
+  static void
+  handle_deprecated_attribute_on_fndecl (tree fndecl,
+					 const AST::Attribute &attr);
 
   static void handle_no_mangle_attribute_on_fndecl (tree fndecl,
 						    const AST::Attribute &attr);
diff --git a/gcc/rust/util/rust-attributes.cc b/gcc/rust/util/rust-attributes.cc
index c36d462537d..870ca21f87c 100644
--- a/gcc/rust/util/rust-attributes.cc
+++ b/gcc/rust/util/rust-attributes.cc
@@ -27,6 +27,7 @@ static const BuiltinAttrDefinition __definitions[] = {
   {"cold", CODE_GENERATION},
   {"cfg", EXPANSION},
   {"cfg_attr", EXPANSION},
+  {"deprecated", STATIC_ANALYSIS},
   {"allow", STATIC_ANALYSIS},
   {"doc", HIR_LOWERING},
   {"must_use", STATIC_ANALYSIS},