Add support for data breakpoints

README.md

@@ -90,6 +90,7 @@ that's not listed.
 - [x] breakpoints with conditions
 - [x] logpoints
 - [x] set exception breakpoints
+- [x] set data breakpoints
 - [x] step over, step into, step out
 - [x] step back, reverse continue
 - [x] Goto

lua/dap.lua

@@ -15,6 +15,7 @@ local ns_pos = 'dap_pos'
 local Session = {}
 local session = nil
 local bp_info = {}
+local data_bp_info = {}
 local last_run = nil
 local terminal_buf
 local deprecation_warning = {}
@@ -50,6 +51,22 @@ M.listeners = {
 }
 
 
+function M.listeners.after.event_initialized.databreakpoints()
+  if session and session.capabilities and session.capabilities.supportsDataBreakpoints then
+    session:_set_data_breakpoints()
+  end
+end
+
+
+function M.listeners.after.event_terminated.databreakpoints()
+  for key, bp in pairs(data_bp_info) do
+    if not bp.canPersist then
+      data_bp_info[key] = nil
+    end
+  end
+end
+
+
 local function from_fallback(_, key)
   return M.defaults.fallback[key]
 end
@@ -560,6 +577,11 @@ function Session:event_stopped(stopped)
       self:_show_exception_info()
     end
 
+    if stopped.reason == 'data breakpoint' then
+      require'dap.repl'.append("Stopped due to data breakpoint"
+                               ..(stopped.description and (': '..stopped.description) or '.'))
+    end
+
     self:request('stackTrace', { threadId = stopped.threadId; }, function(err1, frames_resp)
       if err1 then
         print('Error retrieving stack traces: ' .. err1.message)
@@ -790,6 +812,85 @@ function Session:set_breakpoints(bufexpr, on_done)
   end
 end
 
+
+function Session:_set_data_breakpoint(expression, condition, hit_condition, variables_reference, toggle)
+  if not session.capabilities.supportsDataBreakpoints then
+    vim.notify("Debug adapter does not support data breakpoints", vim.log.levels.ERROR, {})
+    return
+  end
+
+  session:request('dataBreakpointInfo', { name = expression, variablesReference = variables_reference },
+  function(err, response)
+    if err then
+      vim.notify(err.message, vim.log.levels.ERROR, {})
+    else
+      if not response or not response.dataId then
+        vim.notify('Cannot set data breakpoint for "'..expression..'": '
+                   ..((response and response.description) or 'reason unknown'), vim.log.levels.ERROR, {})
+      else
+
+        if toggle and data_bp_info[response.dataId] then
+          data_bp_info[response.dataId] = nil
+          vim.notify('Deleting data breakpoint "'..expression..'" ('..response.dataId..')', vim.log.levels.INFO, {})
+          session:_set_data_breakpoints()
+        else
+          local access_type
+          if response.accessTypes then
+            ui.pick_one(
+            response.accessTypes,
+            'Which access type for "'..expression..'"?: ',
+            function(t) return t end,
+            function(t)
+              if not t then
+                access_type = 'abort'
+              else
+                access_type = t
+              end
+            end
+            )
+          end
+          if access_type ~= 'abort' then
+            data_bp_info[response.dataId] = {
+              dataId = response.dataId,
+              accessType = access_type,
+              condition = condition,
+              hitCondition = hit_condition,
+              canPersist = response.canPersist,
+            }
+            vim.notify('Setting data breakpoint for "'..expression..'" ('..response.dataId..')',
+                       vim.log.levels.INFO,
+                       {})
+          end
+          session:_set_data_breakpoints()
+        end
+      end
+    end
+  end)
+end
+
+
+function Session:_set_data_breakpoints(on_done)
+  if not session.capabilities.supportsDataBreakpoints then
+    vim.notify("Debug adapter does not support data breakpoints", vim.log.levels.ERROR, {})
+    return
+  end
+  local breakpoints = {}
+  for _, bp in pairs(data_bp_info) do
+    table.insert(breakpoints, bp)
+  end
+
+  if #breakpoints > 0 then
+    session:request('setDataBreakpoints', { breakpoints = breakpoints },
+    function(err, _)
+      if err then
+        vim.notify("Failed to set data breakpoints: "..err.message, vim.log.levels.ERROR, {})
+      end
+      if on_done then on_done() end
+    end)
+  end
+end
+
+
 function Session:set_exception_breakpoints(filters, exceptionOptions, on_done)
   if not self.capabilities.exceptionBreakpointFilters then
       print("Debug adapter doesn't support exception breakpoints")
@@ -974,6 +1075,12 @@ function Session:connect(host, port, opts)
   setmetatable(o, self)
   self.__index = self
 
+  for expression, bp in pairs(data_bp_info) do
+    if not bp.canPersist then
+      data_bp_info[expression] = nil
+    end
+  end
+
   local client = uv.new_tcp()
   o.client = {
     write = function(line) client:write(line) end;
@@ -1357,6 +1464,30 @@ function M.set_exception_breakpoints(filters, exceptionOptions)
 end
 
 
+function M.clear_data_breakpoints()
+  data_bp_info = {}
+  if not session then return end
+  session:_set_data_breakpoints()
+end
+
+
+function M.toggle_data_breakpoint(resolve_expression_fn, condition, hit_condition)
+  if not session then return end
+
+  if 'function' == type(resolve_expression_fn) then
+    resolve_expression_fn = resolve_expression_fn()
+  end
+
+  local expression = resolve_expression_fn or vim.fn.expand("<cexpr>")
+  session:_set_data_breakpoint(expression, condition, hit_condition, nil, true)
+end
+
+
+function M.toggle_data_breakpoint_visual_selection(condition, hit_condition)
+  M.set_data_breakpoint(utils.get_visual_selection_text, condition, hit_condition)
+end
+
+
 function M.continue()
   if not session then
     select_config_and_run()

lua/dap/ui/variables.lua

@@ -1,4 +1,5 @@
 local api = vim.api
+local dap = require'dap'
 local utils = require("dap.utils")
 local non_empty = utils.non_empty
 
@@ -8,6 +9,13 @@ M.multiline_variable_display = false
 M.max_win_width = 100
 M.variable_value_separator = " = "
 M.show_types = true
+M.keymaps = {
+  ['<CR>'] = 'toggle_variable_expanded()',
+  ['<2-LeftMouse>'] = 'toggle_variable_expanded()',
+  ['g?'] = 'toggle_multiline_display()',
+  ['b'] = 'toggle_data_breakpoint()',
+  ['<f1>'] = 'show_help()',
+}
 
 local floating_buf = nil
 local floating_win = nil
@@ -99,6 +107,34 @@ local function update_variable_buffer(buf, win)
 end
 
 
+function M.toggle_data_breakpoint(condition, hit_condition)
+  local buf = api.nvim_get_current_buf()
+  local state = variable_buffers[buf]
+  local pos = api.nvim_win_get_cursor(0)
+  if not state then return end
+
+  local variable = state.line_to_variable[pos[1] - 1]
+
+  if variable then
+    local parent
+    for _, p in pairs(state.line_to_variable) do
+      for _, v in pairs(p.variables or {}) do
+        if v == variable then
+          parent = p
+        end
+      end
+    end
+    state.session:_set_data_breakpoint(
+      variable.name,
+      condition,
+      hit_condition,
+      parent and parent.variablesReference,
+      true
+    )
+  end
+end
+
+
 function M.toggle_variable_expanded()
   local buf = api.nvim_get_current_buf()
   local state = variable_buffers[buf]
@@ -184,27 +220,11 @@ local function popup()
   api.nvim_buf_set_option(buf, 'buftype', 'nofile')
   api.nvim_buf_set_option(buf, 'filetype', 'dap-variables')
   api.nvim_buf_set_option(buf, 'syntax', 'dap-variables')
-  api.nvim_buf_set_keymap(
-    buf,
-    "n",
-    "<CR>",
-    "<Cmd>lua require('dap.ui.variables').toggle_variable_expanded()<CR>",
-    {}
-  )
-  api.nvim_buf_set_keymap(
-    buf,
-    "n",
-    "<2-LeftMouse>",
-    "<Cmd>lua require('dap.ui.variables').toggle_variable_expanded()<CR>",
-    {}
-  )
-  api.nvim_buf_set_keymap(
-    buf,
-    "n",
-    "g?",
-    "<Cmd>lua require('dap.ui.variables').toggle_multiline_display()<CR>",
-    {}
-  )
+
+  for key, mapping in pairs(M.keymaps) do
+     api.nvim_buf_set_keymap(buf, "n", key, "<Cmd>lua require('dap.ui.variables')."..mapping.."<CR>", {})
+  end
+
   -- width and height are increased later once variables are written to the buffer
   local opts = vim.lsp.util.make_floating_popup_options(1, 1, {})
   local win = api.nvim_open_win(buf, true, opts)
@@ -216,6 +236,14 @@ function M.resolve_expression()
   return vim.fn.expand("<cexpr>")
 end
 
+function M.show_help()
+  local function filter(item, path)
+    if path[#path] == vim.inspect.METATABLE then return end
+    return item
+  end
+  print("Current keybindings:")
+  print(vim.inspect(M.keymaps, {process=filter}))
+end
 
 local function is_stopped_at_frame()
   local session = require('dap').session()