daemon/lua: fix on 32-bit systems with 64-bit time_t

This improves the heuristics.
The problem would be detected by meson, but not when cross-compiling,
in which case things would mostly run OK, except some lua code/modules.

5 files changed, 37 insertions, 18 deletions

diff --git a/daemon/lua/kres-gen-30.lua b/daemon/lua/kres-gen-30.lua
index 7639e797..f3f8a499 100644
--- a/daemon/lua/kres-gen-30.lua
+++ b/daemon/lua/kres-gen-30.lua
@@ -2,9 +2,10 @@
 
 local ffi = require('ffi')
 --[[ This file is generated by ./kres-gen.sh ]] ffi.cdef[[
-typedef long time_t;
-typedef long __time_t;
-typedef long __suseconds_t;
+
+typedef @time_t@ time_t;
+typedef @time_t@ __time_t;
+typedef @time_t@ __suseconds_t;
 struct timeval {
 	__time_t tv_sec;
 	__suseconds_t tv_usec;
diff --git a/daemon/lua/kres-gen-31.lua b/daemon/lua/kres-gen-31.lua
index e555a6a0..46b349ea 100644
--- a/daemon/lua/kres-gen-31.lua
+++ b/daemon/lua/kres-gen-31.lua
@@ -2,9 +2,10 @@
 
 local ffi = require('ffi')
 --[[ This file is generated by ./kres-gen.sh ]] ffi.cdef[[
-typedef long time_t;
-typedef long __time_t;
-typedef long __suseconds_t;
+
+typedef @time_t@ time_t;
+typedef @time_t@ __time_t;
+typedef @time_t@ __suseconds_t;
 struct timeval {
 	__time_t tv_sec;
 	__suseconds_t tv_usec;
diff --git a/daemon/lua/kres-gen-32.lua b/daemon/lua/kres-gen-32.lua
index 31a5c5dd..88b50ded 100644
--- a/daemon/lua/kres-gen-32.lua
+++ b/daemon/lua/kres-gen-32.lua
@@ -2,9 +2,10 @@
 
 local ffi = require('ffi')
 --[[ This file is generated by ./kres-gen.sh ]] ffi.cdef[[
-typedef long time_t;
-typedef long __time_t;
-typedef long __suseconds_t;
+
+typedef @time_t@ time_t;
+typedef @time_t@ __time_t;
+typedef @time_t@ __suseconds_t;
 struct timeval {
 	__time_t tv_sec;
 	__suseconds_t tv_usec;
diff --git a/daemon/lua/kres-gen.sh b/daemon/lua/kres-gen.sh
index 70afb408..3befd5da 100755
--- a/daemon/lua/kres-gen.sh
+++ b/daemon/lua/kres-gen.sh
@@ -53,12 +53,15 @@ printf -- "local ffi = require('ffi')\n"
 printf -- "--[[ This file is generated by ./kres-gen.sh ]] ffi.cdef[[\n"
 
 # Some system dependencies.  TODO: this generated part isn't perfectly portable.
-${CDEFS} ${LIBKRES} types <<-EOF
-	typedef time_t
-	__time_t
-	__suseconds_t
-	struct timeval
-EOF
+printf "
+typedef @time_t@ time_t;
+typedef @time_t@ __time_t;
+typedef @time_t@ __suseconds_t;
+struct timeval {
+	__time_t tv_sec;
+	__suseconds_t tv_usec;
+};
+"
 
 ## Various types (mainly), from libknot and libkres
 
diff --git a/daemon/lua/meson.build b/daemon/lua/meson.build
index b19777c2..6df5bc5b 100644
--- a/daemon/lua/meson.build
+++ b/daemon/lua/meson.build
@@ -47,10 +47,23 @@ else
   kres_gen_fname = 'kres-gen-30.lua'
 endif
 
+# Exact types around time_t aren't easy to detect, but at least we need the same size.
+time_t_size = meson.get_compiler('c').sizeof('time_t', prefix: '#include <sys/time.h>')
+kres_gen_config = {}
+foreach t: [ 'long', 'long long' ]
+  if meson.get_compiler('c').sizeof(t) == time_t_size
+    kres_gen_config = { 'time_t': t }
+    break
+  endif
+endforeach
+if kres_gen_config == {}
+  error('Unexpected sizeof(time_t) == @0@'.format(time_t_size))
+endif
+
 kres_gen_lua = configure_file(
   input: kres_gen_fname,
   output: 'kres-gen.lua',
-  copy: true,
+  configuration: kres_gen_config,
 )
 
 run_target(  # run manually to re-generate kres-gen.lua
@@ -72,9 +85,9 @@ if get_option('kres_gen_test') and not meson.is_cross_build()
   ]
   # Construct the lua tester as a meson string.
   kres_gen_test_luastr = '''
-    dofile('@0@')
+    dofile('@0@/../../@1@')
     local ffi = require('ffi')
-  '''.format(meson.current_source_dir() / kres_gen_fname)
+  '''.format(meson.current_build_dir(), kres_gen_lua)
   foreach ttc: types_to_check
     # We're careful with adding just includes; otherwise it's more fragile (e.g. linking flags).
     if 'dep' in ttc