lsp: Add support for call hierarchies (#12556)

* LSP: Add support for call hierarchies

* LSP: Add support for call hierarchies

* LSP: Add support for call hierarchies

* LSP: Jump to call location

Jump to the call site instead of jumping to the definition of the
caller/callee.

* LSP: add tests for the call hierarchy callbacks

* Fix linting error

Co-authored-by: Cédric Barreteau <>

1 files changed, 32 insertions, 0 deletions

diff --git a/runtime/lua/vim/lsp/buf.lua b/runtime/lua/vim/lsp/buf.lua
index 839e00c67d..476bb3ba6f 100644
--- a/runtime/lua/vim/lsp/buf.lua
+++ b/runtime/lua/vim/lsp/buf.lua
@@ -143,6 +143,38 @@ function M.document_symbol()
   request('textDocument/documentSymbol', params)
 end
 
+local function pick_call_hierarchy_item(call_hierarchy_items)
+  if not call_hierarchy_items then return end
+  if #call_hierarchy_items == 1 then
+    return call_hierarchy_items[1]
+  end
+  local items = {}
+  for i, item in ipairs(call_hierarchy_items) do
+    local entry = item.detail or item.name
+    table.insert(items, string.format("%d. %s", i, entry))
+  end
+  local choice = vim.fn.inputlist(items)
+  if choice < 1 or choice > #items then
+    return
+  end
+  return choice
+end
+
+function M.incoming_calls()
+  local params = util.make_position_params()
+  request('textDocument/prepareCallHierarchy', params, function(_, _, result)
+    local call_hierarchy_item = pick_call_hierarchy_item(result)
+    vim.lsp.buf_request(0, 'callHierarchy/incomingCalls', { item = call_hierarchy_item })
+  end)
+end
+
+function M.outgoing_calls()
+  local params = util.make_position_params()
+  request('textDocument/prepareCallHierarchy', params, function(_, _, result)
+    local call_hierarchy_item = pick_call_hierarchy_item(result)
+    vim.lsp.buf_request(0, 'callHierarchy/outgoingCalls', { item = call_hierarchy_item })
+  end)
+end
 
 --- Lists all symbols in the current workspace in the quickfix window.
 ---