gccrs: libproc_macro: Add helpers to construct Procmacro

Add some helper functions to create Procmacro tagged unions.

libgrust/ChangeLog:

	* libproc_macro/proc_macro.cc (Procmacro::make_derive):
	Add custom derive macro constructor.
	(Procmacro::make_attribute): Add attribute macro constructor.
	(Procmacro::make_bang): Add bang macro constructor.
	* libproc_macro/proc_macro.h (struct Procmacro):
	Add helper function prototypes.

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

2 files changed, 39 insertions, 4 deletions

diff --git a/libgrust/libproc_macro/proc_macro.cc b/libgrust/libproc_macro/proc_macro.cc
index 03beb89..2e50f0a 100644
--- a/libgrust/libproc_macro/proc_macro.cc
+++ b/libgrust/libproc_macro/proc_macro.cc
@@ -21,3 +21,32 @@
 // <http://www.gnu.org/licenses/>.
 
 #include "proc_macro.h"
+
+namespace ProcMacro {
+
+Procmacro
+Procmacro::make_derive (const char *trait_name, const char **attributes,
+			std::uint64_t size, CustomDeriveMacro macro)
+{
+  ProcmacroPayload payload;
+  payload.custom_derive = {trait_name, attributes, size, macro};
+  return {CUSTOM_DERIVE, payload};
+}
+
+Procmacro
+Procmacro::make_attribute (const char *name, AttributeMacro macro)
+{
+  ProcmacroPayload payload;
+  payload.attribute = {name, macro};
+  return {ATTR, payload};
+}
+
+Procmacro
+Procmacro::make_bang (const char *name, BangMacro macro)
+{
+  ProcmacroPayload payload;
+  payload.bang = {name, macro};
+  return {BANG, payload};
+}
+
+} // namespace ProcMacro
diff --git a/libgrust/libproc_macro/proc_macro.h b/libgrust/libproc_macro/proc_macro.h
index a5ee774..3022203 100644
--- a/libgrust/libproc_macro/proc_macro.h
+++ b/libgrust/libproc_macro/proc_macro.h
@@ -42,9 +42,9 @@ using BangMacro = TokenStream (*) (TokenStream);
 struct CustomDerivePayload
 {
   // TODO: UTF-8 function name
-  char *trait_name;
+  const char *trait_name;
   // TODO: UTF-8 attributes
-  char **attributes;
+  const char **attributes;
   std::uint64_t attr_size;
   CustomDeriveMacro macro;
 };
@@ -52,13 +52,13 @@ struct CustomDerivePayload
 struct AttrPayload
 {
   // TODO: UTF-8 function name
-  char *name;
+  const char *name;
   AttributeMacro macro;
 };
 
 struct BangPayload
 {
-  char *name;
+  const char *name;
   BangMacro macro;
 };
 }
@@ -81,6 +81,12 @@ struct Procmacro
 {
   ProcmacroTag tag;
   ProcmacroPayload payload;
+
+public:
+  Procmacro make_derive (const char *trait_name, const char **attribute,
+			 std::uint64_t size, CustomDeriveMacro macro);
+  Procmacro make_attribute (const char *name, AttributeMacro macro);
+  Procmacro make_bang (const char *name, BangMacro macro);
 };
 
 } // namespace ProcMacro