Function callers_of 

pub fn callers_of<'a>(
    cpg: &'a CodePropertyGraph,
    func_name: &str,
) -> Vec<(&'a Node, &'a Node)>

For a given function name, returns all functions that directly call it.

Each returned tuple contains the caller function node and the callee definition node. The enclosing function is found by walking up Edge::AstChild edges from the call site.

Examples

use icb_graph::graph::{CodePropertyGraph, Node, Edge};
use icb_graph::query::callers_of;
use icb_common::NodeKind;

let mut cpg = CodePropertyGraph::new();
let foo = cpg.graph.add_node(Node {
    kind: NodeKind::Function,
    name: Some("foo".into()),
    usr: Some("foo".into()),
    start_line: 1,
    end_line: 2,
});
let bar = cpg.graph.add_node(Node {
    kind: NodeKind::Function,
    name: Some("bar".into()),
    usr: Some("bar".into()),
    start_line: 5,
    end_line: 6,
});
let call = cpg.graph.add_node(Node {
    kind: NodeKind::CallSite,
    name: Some("bar".into()),
    usr: None,
    start_line: 2,
    end_line: 2,
});
cpg.graph.add_edge(foo, call, Edge::AstChild);
cpg.graph.add_edge(call, bar, Edge::Call);

let callers = callers_of(&cpg, "bar");
assert_eq!(callers.len(), 1);
assert_eq!(callers[0].0.name.as_deref(), Some("foo"));