Formatting

tools/clangd_headers.py

@@ -11,7 +11,7 @@ def header_roots(config):
   for driver in config["query_drivers"]:
     for language in ("c", "c++"):
       result = subprocess.run([driver, "-E", "-v", "-x", language, "-"], input="",
-                              stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True, check=True)
+        stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True, check=True)
       listing = False
       for line in result.stderr.splitlines():
         if line == "#include <...> search starts here:":

tools/docker/Dockerfile

@@ -44,6 +44,11 @@ ENV PATH=/opt/modulus-python/bin:${PATH}
 RUN python -m pip install --no-cache-dir \
     conan==2.26.2
 
+# The path is shared by source builds and exported consumer tooling.
+ARG MODULUS_TOOLS=tools
+COPY ${MODULUS_TOOLS}/docker/format-requirements.txt /tmp/modulus-format-requirements.txt
+RUN python -m pip install --no-cache-dir -r /tmp/modulus-format-requirements.txt
+
 WORKDIR /workspace
 
 RUN mkdir -p /opt && touch /opt/modulus-build-image

tools/docker/format-requirements.txt

@@ -0,0 +1,5 @@
+clang-format==19.1.7
+autopep8==2.3.2
+pycodestyle==2.14.0
+tree-sitter==0.25.2
+tree-sitter-cpp==0.23.4

tools/format.py

@@ -0,0 +1,5 @@
+#!/usr/bin/env python3
+import modulus_tool
+
+if __name__ == "__main__":
+  modulus_tool.run("format")

tools/nvim/modulus.lua

@@ -4,6 +4,71 @@ local function within(path, root)
   return path == root or path:sub(1, #root + 1) == root .. "/"
 end
 
+local function setup_formatting(state)
+  if state.formatting then
+    return
+  end
+  local ok, conform = pcall(require, "conform")
+  if not ok then
+    vim.notify("Modulus formatting requires conform.nvim", vim.log.levels.WARN)
+    return
+  end
+  state.formatting = true
+  local function project(buf)
+    local ft = vim.bo[buf].filetype
+    if ft ~= "c" and ft ~= "cpp" and ft ~= "python" then
+      return nil
+    end
+    return state.project(vim.api.nvim_buf_get_name(buf))
+  end
+  local fallback = conform.formatters_by_ft["_"]
+  for _, ft in ipairs({ "c", "cpp", "python", "*" }) do
+    local original = conform.formatters_by_ft[ft]
+    if ft ~= "*" and (not original or (type(original) == "table" and vim.tbl_isempty(original))) then
+      original = fallback
+    end
+    conform.formatters_by_ft[ft] = function(buf)
+      if project(buf) then
+        if ft == "*" then
+          return {}
+        end
+        return { "modulus", lsp_format = "never", timeout_ms = 10000 }
+      end
+      if type(original) == "function" then
+        return original(buf) or {}
+      end
+      return original or {}
+    end
+  end
+  conform.formatters.modulus = {
+    command = "python3",
+    env = { MODULUS_DIRECT = "0" },
+    args = function(_, context)
+      local root = assert(project(context.buf))
+      local args = vim.uv.fs_stat(root .. "/modulus/cli.py")
+        and { root .. "/tools/format.py" }
+        or { root .. "/modulus.py", "format" }
+      vim.list_extend(args, { "--stdin-filename", context.filename })
+      return args
+    end,
+    cwd = function(_, context) return project(context.buf) end,
+    stdin = true,
+  }
+  -- LazyVim already owns save/manual formatting and its global/buffer toggles.
+  local has_save, save_hooks = pcall(vim.api.nvim_get_autocmds, { event = "BufWritePre", group = "Conform" })
+  if not rawget(_G, "LazyVim") and (not has_save or #save_hooks == 0) then
+    vim.api.nvim_create_autocmd("BufWritePre", {
+      group = vim.api.nvim_create_augroup("ModulusFormat", { clear = true }),
+      callback = function(event)
+        if project(event.buf) and vim.g.autoformat ~= false and vim.b[event.buf].autoformat ~= false
+          and not vim.g.disable_autoformat and not vim.b[event.buf].disable_autoformat then
+          conform.format({ bufnr = event.buf, lsp_format = "never", timeout_ms = 10000 })
+        end
+      end,
+    })
+  end
+end
+
 function M.setup(root)
   if vim.fn.has("nvim-0.11") ~= 1 then
     vim.notify("Modulus container clangd requires Neovim 0.11+", vim.log.levels.ERROR)
@@ -13,7 +78,7 @@ function M.setup(root)
   -- Finish LazyVim's server setup before changing only the command and root routing.
   local has_lazy, lazy = pcall(require, "lazy")
   if has_lazy then
-    lazy.load({ plugins = { "nvim-lspconfig" } })
+    lazy.load({ plugins = { "nvim-lspconfig", "conform.nvim" } })
   end
   local state = rawget(_G, "modulus_clangd")
   if not state then
@@ -85,6 +150,7 @@ function M.setup(root)
     command = { "python3", root .. "/modulus.py", "clangd" }
   end
   state.roots[root] = command
+  setup_formatting(state)
   for _, client in ipairs(vim.lsp.get_clients({ name = "clangd" })) do
     if not client.config._modulus_container and client.config.root_dir and within(client.config.root_dir, root) then
       client:stop()