Use ast to get all function calls in a function

Question

I'm trying to list all function call in a function using ast. But having trouble understanding how it is suppose to be used. I have been able to get this far.

set := token.NewFileSet()
packs, err := parser.ParseFile(set, serviceFile, nil, 0)
if err != nil {
    fmt.Println("Failed to parse package:", err)
    os.Exit(1)
}

funcs := []*ast.FuncDecl{}
for _, d := range packs.Decls {
    if fn, isFn := d.(*ast.FuncDecl); isFn {
        funcs = append(funcs, fn)
    }
}

I have inspected funcs. I get to funcs[n1].Body.List[n2]. But after this i don't understand how i'm suppose to read the underlaying data.X.Fun.data.Sel.name (got it from evaluation in gogland) to get name of the function being called.

Answer 1

Ok so what i found is that you have to a lot of casting to actually extract the data.

Here is an example on how to do extract the func call in a func.

for _, function := range funcs {
    extractFuncCallInFunc(function.Body.List)
}

func extractFuncCallInFunc(stmts []ast.Stmt) {
    for _, stmt := range funcs {
        if exprStmt, ok := stmt.(*ast.ExprStmt); ok {
            if call, ok := exprStmt.X.(*ast.CallExpr); ok {
                if fun, ok := call.Fun.(*ast.SelectorExpr); ok {
                    funcName := fun.Sel.Name
                }
            }
        }
    }
}

I also found this with kind of help with finding out what you need to cast it to. http://goast.yuroyoro.net/