gccrs: New Error Code Framework

Updated ErrorCode struct to enum class to enforce proper
error codes, similiar to rustc. For converting the enum
to the respective error code, I used a map and updated
make_description & make_url function accordingly and
also removes the memory leak from the previous frame-
work.
Also, added macro to safely convert the enum number
to string.

gcc/rust/ChangeLog:

	* backend/rust-compile-intrinsic.cc (Intrinsics::compile):
	Formatted according to enum class.
	* checks/errors/rust-feature-gate.cc (FeatureGate::gate): likewise.
	* checks/errors/rust-unsafe-checker.cc (check_unsafe_call): likewise.
	* hir/rust-ast-lower-base.cc (struct_field_name_exists): likewise.
	* resolve/rust-ast-resolve-expr.cc (ResolveExpr::visit): likewise.
	* resolve/rust-ast-resolve-path.cc (ResolvePath::resolve_path): likewise.
	* resolve/rust-ast-resolve-pattern.cc (PatternDeclaration::go): likewise.
	(PatternDeclaration::add_new_binding): likewise.
	* resolve/rust-ast-resolve-type.cc (ResolveRelativeTypePath::go): likewise.
	* resolve/rust-ast-verify-assignee.h: likewise.
	* rust-diagnostics.cc: updated make_desc & url function for enum class.
	* rust-diagnostics.h (struct ErrorCode): removed struct to switch to enum.
	(enum class): Switched from errorcode struct to enum class.
	(XSTR): Macro for converting enum to string.
	(STR): macro Used by XSTR for converting to string.
	(ERROR_CODE): macro for appending `E` to the start.
	(TABLE_TO_MAP): macro used by map for check.
	* typecheck/rust-casts.cc (TypeCastRules::emit_cast_error):
	Formatted according to enum class.
	* typecheck/rust-hir-path-probe.h: likewise.
	* typecheck/rust-hir-type-check-expr.cc (TypeCheckExpr::visit): likewise.
	* typecheck/rust-hir-type-check-implitem.cc (TypeCheckImplItemWithTrait::visit):
	likewise.
	* typecheck/rust-hir-type-check-item.cc: likewise.
	* typecheck/rust-hir-type-check-pattern.cc (TypeCheckPattern::visit): likewise.
	(emit_invalid_field_error): likewise.
	* typecheck/rust-hir-type-check-struct.cc (TypeCheckStructExpr::resolve):
	likewise.
	* typecheck/rust-tyty-call.cc (emit_unexpected_argument_error): likewise.
	(TypeCheckCallExpr::visit): likewise.
	* typecheck/rust-tyty-subst.cc (SubstitutionRef::get_mappings_from_generic_args):
	likewise.
	* typecheck/rust-tyty.cc (BaseType::bounds_compatible): likewise.

Signed-off-by: Muhammad Mahad <[email protected]>

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

@@ -228,7 +228,7 @@ Intrinsics::compile (TyTy::FnType *fntype)
     return it->second (ctx, fntype);
 
   location_t locus = ctx->get_mappings ()->lookup_location (fntype->get_ref ());
-  rust_error_at (locus, ErrorCode ("E0093"),
+  rust_error_at (locus, ErrorCode::E0093,
 		 "unrecognized intrinsic function: %<%s%>",
 		 fntype->get_identifier ().c_str ());
 

gcc/rust/checks/errors/rust-feature-gate.cc

@@ -79,7 +79,7 @@ FeatureGate::gate (Feature::Name name, Location loc,
 	      "<https://github.com/rust-lang/rust/issues/%u> for more "
 	      "information. add `#![feature(%s)]` to the crate attributes to "
 	      "enable.";
-	  rust_error_at (loc, ErrorCode ("E0658"), fmt_str, error_msg.c_str (),
+	  rust_error_at (loc, ErrorCode::E0658, fmt_str, error_msg.c_str (),
 			 issue, issue, feature.as_string ().c_str ());
 	}
       else

gcc/rust/checks/errors/rust-unsafe-checker.cc

@@ -86,7 +86,7 @@ static void
 check_unsafe_call (HIR::Function *fn, location_t locus, const std::string &kind)
 {
   if (fn->get_qualifiers ().is_unsafe ())
-    rust_error_at (locus, ErrorCode ("E0133"),
+    rust_error_at (locus, ErrorCode::E0133,
 		   "call to unsafe %s requires unsafe function or block",
 		   kind.c_str ());
 }

gcc/rust/hir/rust-ast-lower-base.cc

@@ -681,8 +681,7 @@ struct_field_name_exists (std::vector<HIR::StructField> &fields,
 	{
 	  rich_location r (line_table, new_field.get_locus ());
 	  r.add_range (field.get_locus ());
-	  rust_error_at (r, ErrorCode ("E0124"),
-			 "field %qs is already declared",
+	  rust_error_at (r, ErrorCode::E0124, "field %qs is already declared",
 			 field.get_field_name ().as_string ().c_str ());
 	  return true;
 	}

gcc/rust/resolve/rust-ast-resolve-expr.cc

@@ -173,7 +173,7 @@ ResolveExpr::visit (AST::IdentifierExpr &expr)
     }
   else
     {
-      rust_error_at (expr.get_locus (), ErrorCode ("E0425"),
+      rust_error_at (expr.get_locus (), ErrorCode::E0425,
 		     "cannot find value %qs in this scope",
 		     expr.as_string ().c_str ());
     }

gcc/rust/resolve/rust-ast-resolve-path.cc

@@ -62,7 +62,7 @@ ResolvePath::resolve_path (AST::PathInExpression *expr)
       bool in_middle_of_path = i > 0;
       if (in_middle_of_path && segment.is_lower_self_seg ())
 	{
-	  rust_error_at (segment.get_locus (), ErrorCode ("E0433"),
+	  rust_error_at (segment.get_locus (), ErrorCode::E0433,
 			 "failed to resolve: %<%s%> in paths can only be used "
 			 "in start position",
 			 segment.as_string ().c_str ());
@@ -206,7 +206,7 @@ ResolvePath::resolve_path (AST::PathInExpression *expr)
 	}
       else if (is_first_segment)
 	{
-	  rust_error_at (segment.get_locus (), ErrorCode ("E0433"),
+	  rust_error_at (segment.get_locus (), ErrorCode::E0433,
 			 "Cannot find path %<%s%> in this scope",
 			 segment.as_string ().c_str ());
 	  return UNKNOWN_NODEID;

gcc/rust/resolve/rust-ast-resolve-pattern.cc

@@ -42,7 +42,7 @@ PatternDeclaration::go (AST::Pattern *pattern, Rib::ItemType type,
       auto ident = map_entry.first; // key
       auto info = map_entry.second; // value
 
-      rust_error_at (info.get_locus (), ErrorCode ("E0408"),
+      rust_error_at (info.get_locus (), ErrorCode::E0408,
 		     "variable '%s' is not bound in all patterns",
 		     ident.as_string ().c_str ());
     }
@@ -53,7 +53,7 @@ PatternDeclaration::go (AST::Pattern *pattern, Rib::ItemType type,
       auto info = map_entry.second; // value
 
       rust_error_at (
-	info.get_locus (), ErrorCode ("E0409"),
+	info.get_locus (), ErrorCode::E0409,
 	"variable '%s' is bound inconsistently across pattern alternatives",
 	ident.as_string ().c_str ());
     }
@@ -278,15 +278,15 @@ PatternDeclaration::add_new_binding (Identifier ident, NodeId node_id,
     {
       if (type == Rib::ItemType::Param)
 	{
-	  rust_error_at (info.get_locus (), ErrorCode ("E0415"),
+	  rust_error_at (info.get_locus (), ErrorCode::E0415,
 			 "identifier '%s' is bound more than once in the "
 			 "same parameter list",
 			 ident.as_string ().c_str ());
 	}
       else
 	{
 	  rust_error_at (
-	    info.get_locus (), ErrorCode ("E0416"),
+	    info.get_locus (), ErrorCode::E0416,
 	    "identifier '%s' is bound more than once in the same pattern",
 	    ident.as_string ().c_str ());
 	}

gcc/rust/resolve/rust-ast-resolve-type.cc

@@ -98,7 +98,7 @@ ResolveRelativeTypePath::go (AST::TypePath &path, NodeId &resolved_node_id)
       bool in_middle_of_path = i > 0;
       if (in_middle_of_path && segment->is_lower_self_seg ())
 	{
-	  rust_error_at (segment->get_locus (), ErrorCode ("E0433"),
+	  rust_error_at (segment->get_locus (), ErrorCode::E0433,
 			 "failed to resolve: %<%s%> in paths can only be used "
 			 "in start position",
 			 segment->as_string ().c_str ());

gcc/rust/resolve/rust-ast-verify-assignee.h

@@ -35,7 +35,7 @@ class VerifyAsignee : public ResolverBase
     VerifyAsignee checker;
     assignee->accept_vis (checker);
     if (!checker.ok)
-      rust_error_at (assignee->get_locus (), ErrorCode ("E0070"),
+      rust_error_at (assignee->get_locus (), ErrorCode::E0070,
 		     "invalid left-hand side of assignment");
     return checker.ok;
   }

gcc/rust/rust-diagnostics.cc

@@ -199,13 +199,16 @@ class rust_error_code_rule : public diagnostic_metadata::rule
 
   char *make_description () const final override
   {
-    return xstrdup (m_code.m_str);
+    std::string errstring (ErrorCodeString.at (m_code));
+    char *desc = new char[errstring.size () + 1];
+    std::strcpy (desc, errstring.c_str ());
+    return desc;
   }
 
   char *make_url () const final override
   {
-    return concat ("https://doc.rust-lang.org/error-index.html#", m_code.m_str,
-		   NULL);
+    return concat ("https://doc.rust-lang.org/error-index.html#",
+		   ErrorCodeString.at (m_code), NULL);
   }
 
 private: