gccrs: Collect procedural macros in the crate

Collect informations on procedural macros in the compiled crate. For
attribute and bang procedural macros we only require the final address
as well as the name of the function. Derive procedural macros are a bit
different, we collect the fonction's address through it's fndecl tree as
well as the trait's name and the multiple attributes.

gcc/rust/ChangeLog:

	* backend/rust-compile-base.cc (HIRCompileBase::setup_fndecl):
	Make the function non static in order to be able to access the
	compile context. Also add the whole proc macro infomrmation
	collection.
	(get_attributes): Add a function to retrieve the different
	attributes from a derive procedural macro definition attribute.
	(get_trait_name): Add a function to retrieve the trait name from
	a derive procedural macro definition attribute.
	* backend/rust-compile-base.h: Add function prototypes.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

2 files changed, 63 insertions, 17 deletions

diff --git a/gcc/rust/backend/rust-compile-base.cc b/gcc/rust/backend/rust-compile-base.cc
index d552a67..fe6d5e3 100644
--- a/gcc/rust/backend/rust-compile-base.cc
+++ b/gcc/rust/backend/rust-compile-base.cc
@@ -117,15 +117,15 @@ HIRCompileBase::setup_fndecl (tree fndecl, bool is_main_entry_point,
 	}
       else if (is_proc_macro)
 	{
-	  handle_proc_macro_attribute_on_fndecl (fndecl, attr);
+	  handle_bang_proc_macro_attribute_on_fndecl (fndecl, attr);
 	}
       else if (is_proc_macro_attribute)
 	{
-	  handle_proc_macro_attribute_attribute_on_fndecl (fndecl, attr);
+	  handle_attribute_proc_macro_attribute_on_fndecl (fndecl, attr);
 	}
       else if (is_proc_macro_derive)
 	{
-	  handle_proc_macro_derive_attribute_on_fndecl (fndecl, attr);
+	  handle_derive_proc_macro_attribute_on_fndecl (fndecl, attr);
 	}
     }
 }
@@ -138,24 +138,71 @@ handle_proc_macro_common (tree fndecl, const AST::Attribute &attr)
 }
 
 void
-HIRCompileBase::handle_proc_macro_attribute_on_fndecl (
+HIRCompileBase::handle_bang_proc_macro_attribute_on_fndecl (
   tree fndecl, const AST::Attribute &attr)
 {
   handle_proc_macro_common (fndecl, attr);
+  ctx->collect_bang_proc_macro (fndecl);
 }
 
 void
-HIRCompileBase::handle_proc_macro_attribute_attribute_on_fndecl (
+HIRCompileBase::handle_attribute_proc_macro_attribute_on_fndecl (
   tree fndecl, const AST::Attribute &attr)
 {
   handle_proc_macro_common (fndecl, attr);
+  ctx->collect_attribute_proc_macro (fndecl);
+}
+
+static std::vector<std::string>
+get_attributes (const AST::Attribute &attr)
+{
+  std::vector<std::string> result;
+
+  rust_assert (attr.get_attr_input ().get_attr_input_type ()
+	       == Rust::AST::AttrInput::TOKEN_TREE);
+  const auto &tt
+    = static_cast<const AST::DelimTokenTree &> (attr.get_attr_input ());
+
+  // TODO: Should we rely on fixed index ? Should we search for the
+  // attribute tokentree instead ?
+  if (tt.get_token_trees ().size () > 3)
+    {
+      rust_assert (tt.get_token_trees ()[3]->as_string () == "attributes");
+
+      auto attributes = static_cast<const AST::DelimTokenTree *> (
+	tt.get_token_trees ()[4].get ());
+      auto &token_trees = attributes->get_token_trees ();
+
+      for (auto i = token_trees.cbegin () + 1; // Skip opening parenthesis
+	   i < token_trees.cend ();
+	   i += 2) // Skip comma and closing parenthesis
+	{
+	  result.push_back ((*i)->as_string ());
+	}
+    }
+  return result;
+}
+
+static std::string
+get_trait_name (const AST::Attribute &attr)
+{
+  rust_assert (attr.get_attr_input ().get_attr_input_type ()
+	       == Rust::AST::AttrInput::TOKEN_TREE);
+  const auto &tt
+    = static_cast<const AST::DelimTokenTree &> (attr.get_attr_input ());
+  return tt.get_token_trees ()[1]->as_string ();
 }
 
 void
-HIRCompileBase::handle_proc_macro_derive_attribute_on_fndecl (
+HIRCompileBase::handle_derive_proc_macro_attribute_on_fndecl (
   tree fndecl, const AST::Attribute &attr)
 {
   handle_proc_macro_common (fndecl, attr);
+
+  attr.get_attr_input ().parse_to_meta_item ();
+  CustomDeriveInfo macro
+    = {fndecl, get_trait_name (attr), get_attributes (attr)};
+  ctx->collect_derive_proc_macro (macro);
 }
 
 void
diff --git a/gcc/rust/backend/rust-compile-base.h b/gcc/rust/backend/rust-compile-base.h
index 56b29a7..41907ec 100644
--- a/gcc/rust/backend/rust-compile-base.h
+++ b/gcc/rust/backend/rust-compile-base.h
@@ -102,24 +102,23 @@ protected:
 
   static tree unit_expression (Context *ctx, location_t locus);
 
-  static void setup_fndecl (tree fndecl, bool is_main_entry_point,
-			    bool is_generic_fn, HIR::Visibility &visibility,
-			    const HIR::FunctionQualifiers &qualifiers,
-			    const AST::AttrVec &attrs);
+  void setup_fndecl (tree fndecl, bool is_main_entry_point, bool is_generic_fn,
+		     HIR::Visibility &visibility,
+		     const HIR::FunctionQualifiers &qualifiers,
+		     const AST::AttrVec &attrs);
 
   static void handle_inline_attribute_on_fndecl (tree fndecl,
 						 const AST::Attribute &attr);
 
-  static void
-  handle_proc_macro_attribute_on_fndecl (tree fndecl,
-					 const AST::Attribute &attr);
+  void handle_bang_proc_macro_attribute_on_fndecl (tree fndecl,
+						   const AST::Attribute &attr);
 
-  static void
-  handle_proc_macro_attribute_attribute_on_fndecl (tree fndecl,
+  void
+  handle_attribute_proc_macro_attribute_on_fndecl (tree fndecl,
 						   const AST::Attribute &attr);
 
-  static void
-  handle_proc_macro_derive_attribute_on_fndecl (tree fndecl,
+  void
+  handle_derive_proc_macro_attribute_on_fndecl (tree fndecl,
 						const AST::Attribute &attr);
 
   static void handle_cold_attribute_on_fndecl (tree fndecl,