Add automatic generation of headers

- The 'stripdecls.py' script replaces declarations in all headers by includes to
  generated headers.
  `ag '#\s*if(?!ndef NEOVIM_).*((?!#\s*endif).*\n)*#ifdef INCLUDE_GENERATED'`
  was used for this.
- Add and integrate gendeclarations.lua into the build system to generate the
  required includes.
- Add -Wno-unused-function
- Made a bunch of old-style definitions ANSI

This adds a requirement: all type and structure definitions must be present
before INCLUDE_GENERATED_DECLARATIONS-protected include.

Warning: mch_expandpath (path.h.generated.h) was moved manually. So far it is
the only exception.

1 files changed, 232 insertions, 0 deletions

diff --git a/scripts/gendeclarations.lua b/scripts/gendeclarations.lua
new file mode 100755
index 0000000000..311ed8b527
--- /dev/null
+++ b/scripts/gendeclarations.lua
@@ -0,0 +1,232 @@
+#!/usr/bin/lua
+
+local fname = arg[1]
+local static_fname = arg[2]
+local non_static_fname = arg[3]
+local cpp = arg[4]
+
+cpp = cpp:gsub(' %-DINCLUDE_GENERATED_DECLARATIONS ', ' ')
+
+local lpeg = require('lpeg')
+
+local fold = function (func, ...)
+  local result = nil
+  for i, v in ipairs({...}) do
+    if result == nil then
+      result = v
+    else
+      result = func(result, v)
+    end
+  end
+  return result
+end
+
+local folder = function (func)
+  return function (...)
+    return fold(func, ...)
+  end
+end
+
+local lit = lpeg.P
+local set = function(...)
+  return lpeg.S(fold(function (a, b) return a .. b end, ...))
+end
+local any_character = lpeg.P(1)
+local rng = function(s, e) return lpeg.R(s .. e) end
+local concat = folder(function (a, b) return a * b end)
+local branch = folder(function (a, b) return a + b end)
+local one_or_more = function(v) return v ^ 1 end
+local two_or_more = function(v) return v ^ 2 end
+local any_amount = function(v) return v ^ 0 end
+local one_or_no = function(v) return v ^ -1 end
+local look_behind = lpeg.B
+local look_ahead = function(v) return #v end
+local neg_look_ahead = function(v) return -v end
+local neg_look_behind = function(v) return -look_behind(v) end
+
+local w = branch(
+  rng('a', 'z'),
+  rng('A', 'Z'),
+  lit('_')
+)
+local aw = branch(
+  w,
+  rng('0', '9')
+)
+local s = set(' ', '\n', '\t')
+local raw_word = concat(w, any_amount(aw))
+local right_word = concat(
+  raw_word,
+  neg_look_ahead(aw)
+)
+local word = concat(
+  neg_look_behind(aw),
+  right_word
+)
+local spaces = any_amount(branch(
+  s,
+  -- Comments are really handled by preprocessor, so the following is not needed
+  concat(
+    lit('/*'),
+    any_amount(concat(
+      neg_look_ahead(lit('*/')),
+      any_character
+    )),
+    lit('*/')
+  ),
+  concat(
+    lit('//'),
+    any_amount(concat(
+      neg_look_ahead(lit('\n')),
+      any_character
+    )),
+    lit('\n')
+  )
+))
+local typ_part = concat(
+  word,
+  any_amount(concat(
+    spaces,
+    lit('*')
+  )),
+  spaces
+)
+local typ = one_or_more(typ_part)
+local typ_id = two_or_more(typ_part)
+local arg = typ_id         -- argument name is swallowed by typ
+local pattern = concat(
+  typ_id,                  -- return type with function name
+  spaces,
+  lit('('),
+  spaces,
+  one_or_no(branch(        -- function arguments
+    concat(
+      arg,                 -- first argument, does not require comma
+      any_amount(concat(   -- following arguments, start with a comma
+        spaces,
+        lit(','),
+        spaces,
+        arg,
+        any_amount(concat(
+          lit('['),
+          spaces,
+          any_amount(aw),
+          spaces,
+          lit(']')
+        ))
+      )),
+      one_or_no(concat(
+        spaces,
+        lit(','),
+        spaces,
+        lit('...')
+      ))
+    ),
+    lit('void')            -- also accepts just void
+  )),
+  spaces,
+  lit(')'),
+  any_amount(concat(       -- optional attributes
+    spaces,
+    lit('FUNC_ATTR_'),
+    any_amount(aw),
+    one_or_no(concat(      -- attribute argument
+      spaces,
+      lit('('),
+      any_amount(concat(
+        neg_look_ahead(lit(')')),
+        any_character
+      )),
+      lit(')')
+    ))
+  )),
+  look_ahead(concat(       -- definition must be followed by "{"
+    spaces,
+    lit('{')
+  ))
+)
+
+if fname == '--help' then
+  print'Usage:'
+  print()
+  print'  gendeclarations.lua definitions.c static.h non-static.h "cc -E …"'
+  os.exit()
+end
+
+local pipe = io.popen(cpp .. ' -DDO_NOT_DEFINE_EMPTY_ATTRIBUTES ' .. fname, 'r')
+local text = pipe:read('*a')
+if not pipe:close() then
+  os.exit(2)
+end
+
+local header = [[
+#ifndef DEFINE_FUNC_ATTRIBUTES
+# define DEFINE_FUNC_ATTRIBUTES
+#endif
+#include "nvim/func_attr.h"
+#undef DEFINE_FUNC_ATTRIBUTES
+]]
+
+local footer = [[
+#include "nvim/func_attr.h"
+]]
+
+local non_static = header
+local static = header
+
+local filepattern = '^# %d+ "[^"]-/?([^"/]+)"'
+local curfile
+
+init = 0
+curfile = nil
+neededfile = fname:match('[^/]+$')
+while init ~= nil do
+  init = text:find('\n', init)
+  if init == nil then
+    break
+  end
+  init = init + 1
+  if text:sub(init, init) == '#' then
+    file = text:match(filepattern, init)
+    if file ~= nil then
+      curfile = file
+    end
+  elseif curfile == neededfile then
+    s = init
+    e = pattern:match(text, init)
+    if e ~= nil then
+      local declaration = text:sub(s, e - 1)
+      -- Comments are really handled by preprocessor, so the following is not 
+      -- needed
+      declaration = declaration:gsub('/%*.-%*/', '')
+      declaration = declaration:gsub('//.-\n', '\n')
+
+      declaration = declaration:gsub('\n', ' ')
+      declaration = declaration:gsub('%s+', ' ')
+      declaration = declaration:gsub(' ?%( ?', '(')
+      declaration = declaration:gsub(' ?%) ?', ')')
+      declaration = declaration:gsub(' ?, ?', ', ')
+      declaration = declaration:gsub(' ?(%*+) ?', ' %1')
+      declaration = declaration:gsub(' ?(FUNC_ATTR_)', ' %1')
+      declaration = declaration:gsub(' $', '')
+      declaration = declaration .. ';\n'
+      if text:sub(s, s + 5) == 'static' then
+        static = static .. declaration
+      else
+        non_static = non_static .. declaration
+      end
+    end
+  end
+end
+
+non_static = non_static .. footer
+static = static .. footer
+
+local F
+F = io.open(static_fname, 'w')
+F:write(static)
+F:close()
+
+F = io.open(non_static_fname, 'w')
+F:write(non_static)
+F:close()