Is there a way to to to get the enum type of a value in GCC tree structure?

I'm writing a GCC plugin for GCC 9 and I've got the following problem:

Imagine a simple initialisation:

enum en{ENUM_VAL1, ENUM_VAL2, ...};

int a = ENUM_VAL1;

What I would like it to be able to do is extracting the information that a's value is an enum value defined by the enumeration en.

What I am doing currently is jumping in on the PLUGIN_ON_FINISH_DECL event, giving me the VAR_DECL tree representing this declaration.

Using the macro DECL_INITIAL I am able to to get the value node of this declaration. However, the returned node of this macros is an INTEGER_CST node. I am so far unable to extract from this that this value in fact is an enum value.

Is there any way to do so?