build: allow IWYU to fix includes for all .c files

Allow Include What You Use to remove unnecessary includes and only
include what is necessary. This helps with reducing compilation times
and makes it easier to visualise which dependencies are actually
required.

Work on https://github.com/neovim/neovim/issues/549, but doesn't close
it since this only works fully for .c files and not headers.

3 files changed, 91 insertions, 0 deletions

diff --git a/src/nvim/generators/gen_api_dispatch.lua b/src/nvim/generators/gen_api_dispatch.lua
index 6894b7a6df..d4fe455f82 100644
--- a/src/nvim/generators/gen_api_dispatch.lua
+++ b/src/nvim/generators/gen_api_dispatch.lua
@@ -189,6 +189,35 @@ funcs_metadata_output:close()
 -- start building the dispatch wrapper output
 local output = io.open(dispatch_outputf, 'wb')
 
+
+-- ===========================================================================
+-- NEW API FILES MUST GO HERE.
+--
+--  When creating a new API file, you must include it here,
+--  so that the dispatcher can find the C functions that you are creating!
+-- ===========================================================================
+output:write([[
+#include "nvim/log.h"
+#include "nvim/map.h"
+#include "nvim/msgpack_rpc/helpers.h"
+#include "nvim/vim.h"
+
+#include "nvim/api/autocmd.h"
+#include "nvim/api/buffer.h"
+#include "nvim/api/command.h"
+#include "nvim/api/deprecated.h"
+#include "nvim/api/extmark.h"
+#include "nvim/api/options.h"
+#include "nvim/api/tabpage.h"
+#include "nvim/api/ui.h"
+#include "nvim/api/vim.h"
+#include "nvim/api/vimscript.h"
+#include "nvim/api/win_config.h"
+#include "nvim/api/window.h"
+#include "nvim/ui_client.h"
+
+]])
+
 local function real_type(type)
   local rv = type
   local rmatch = string.match(type, "Dict%(([_%w]+)%)")
diff --git a/src/nvim/generators/gen_eval.lua b/src/nvim/generators/gen_eval.lua
index 8e6d1f2634..9159a3a200 100644
--- a/src/nvim/generators/gen_eval.lua
+++ b/src/nvim/generators/gen_eval.lua
@@ -27,6 +27,31 @@ local hashy = require'generators.hashy'
 
 local hashpipe = io.open(funcsfname, 'wb')
 
+hashpipe:write([[
+#include "nvim/arglist.h"
+#include "nvim/cmdexpand.h"
+#include "nvim/cmdhist.h"
+#include "nvim/digraph.h"
+#include "nvim/eval/funcs.h"
+#include "nvim/eval/typval.h"
+#include "nvim/eval/vars.h"
+#include "nvim/ex_docmd.h"
+#include "nvim/ex_getln.h"
+#include "nvim/fold.h"
+#include "nvim/getchar.h"
+#include "nvim/insexpand.h"
+#include "nvim/mapping.h"
+#include "nvim/match.h"
+#include "nvim/mbyte.h"
+#include "nvim/menu.h"
+#include "nvim/move.h"
+#include "nvim/quickfix.h"
+#include "nvim/search.h"
+#include "nvim/sign.h"
+#include "nvim/testing.h"
+
+]])
+
 local funcs = require('eval').funcs
 for _, func in pairs(funcs) do
   if func.float_func then
diff --git a/src/nvim/generators/gen_ex_cmds.lua b/src/nvim/generators/gen_ex_cmds.lua
index 255c415a4d..ac60b9f8e9 100644
--- a/src/nvim/generators/gen_ex_cmds.lua
+++ b/src/nvim/generators/gen_ex_cmds.lua
@@ -49,6 +49,43 @@ enumfile:write([[
 typedef enum CMD_index {
 ]])
 defsfile:write(string.format([[
+#include "nvim/arglist.h"
+#include "nvim/autocmd.h"
+#include "nvim/buffer.h"
+#include "nvim/cmdhist.h"
+#include "nvim/debugger.h"
+#include "nvim/diff.h"
+#include "nvim/digraph.h"
+#include "nvim/eval.h"
+#include "nvim/eval/userfunc.h"
+#include "nvim/eval/vars.h"
+#include "nvim/ex_cmds.h"
+#include "nvim/ex_cmds2.h"
+#include "nvim/ex_docmd.h"
+#include "nvim/ex_eval.h"
+#include "nvim/ex_session.h"
+#include "nvim/hardcopy.h"
+#include "nvim/help.h"
+#include "nvim/locale.h"
+#include "nvim/lua/executor.h"
+#include "nvim/mapping.h"
+#include "nvim/mark.h"
+#include "nvim/match.h"
+#include "nvim/menu.h"
+#include "nvim/message.h"
+#include "nvim/ops.h"
+#include "nvim/option.h"
+#include "nvim/profile.h"
+#include "nvim/quickfix.h"
+#include "nvim/runtime.h"
+#include "nvim/sign.h"
+#include "nvim/spell.h"
+#include "nvim/spellfile.h"
+#include "nvim/syntax.h"
+#include "nvim/undo.h"
+#include "nvim/usercmd.h"
+#include "nvim/version.h"
+
 static const int command_count = %u;
 static CommandDefinition cmdnames[%u] = {
 ]], #defs, #defs))