Use integer types for enums in JSON (Fixes iovisor#2615)

The JSON generated for enums wasn't being handled, and caused
exceptions. Since the enum values aren't needed (and would've been
useless without the associated numerical values, anyway), just use the
matching integer type instead.

src/cc/json_map_decl_visitor.cc

@@ -41,7 +41,6 @@ class BMapDeclVisitor : public clang::RecursiveASTVisitor<BMapDeclVisitor> {
  bool VisitTypedefType(const clang::TypedefType *T);
  bool VisitTagType(const clang::TagType *T);
  bool VisitPointerType(const clang::PointerType *T);
- bool VisitEnumConstantDecl(clang::EnumConstantDecl *D);
  bool VisitEnumDecl(clang::EnumDecl *D);
  bool VisitAttr(clang::Attr *A);
 
@@ -93,22 +92,8 @@ bool BMapDeclVisitor::VisitFieldDecl(FieldDecl *D) {
  return true;
 }
 
-bool BMapDeclVisitor::VisitEnumConstantDecl(EnumConstantDecl *D) {
- result_ += "\"";
- result_ += D->getName();
- result_ += "\",";
- return false;
-}
-
 bool BMapDeclVisitor::VisitEnumDecl(EnumDecl *D) {
- result_ += "[\"";
- result_ += D->getName();
- result_ += "\", [";
- for (auto it = D->enumerator_begin(); it != D->enumerator_end(); ++it) {
- TraverseDecl(*it);
- }
- result_.erase(result_.end() - 1);
- result_ += "], \"enum\"]";
+ TraverseType(D->getIntegerType());
  return false;
 }
 

tests/python/test_clang.py

@@ -944,6 +944,7 @@ def test_enumerations(self):
 BPF_HASH(drops, struct a);
  """
  b = BPF(text=text)
+ t = b['drops']
 
  def test_int128_types(self):
  text = """