Improved Lua version detection and Lua 5.3 support (#132)

* libtu/Makefile: it's C89, not C98

* Lua 5.3 removed deprecated variadic function `arg' parameter

Variadic functions were introduced in 5.0, but the method of accessing
them changed in 5.1. This makes the code incompatible with 5.0 (it is
already incompatible since at least b2b1755), which will be removed
from the build system in a subsequent commit.

Fixes #124. See also #90.

* Remove Lua 5.0 from the build system and improve lua-detect.mk

Lua doesn't include an official pkg-config file, therefore we can't rely on
pkg-config variables like "V" or "major_version" - on my system, it detected
the 5.3 library/cflags and used the 5.1 lua/luac binaries (I have both installed
and there was a fallback to 5.1 if it couldn't query these variables from
pkg-config).

build/lua-detect.mk

@@ -3,7 +3,7 @@
 # It uses pkg-config to do this, but will fail if you have liblua, but
 # not the corresponding interpreter/compiler. Let's say you have liblua5.2
 # but want to build with liblua5.1 (for which you have the lib, interpreter
-# and compiler), you can override by setting LUA_VERSION=5.0 when invoking
+# and compiler), you can override by setting LUA_VERSION=5.1 when invoking
 # make.
 #
 # If successful, sets the following variables:
@@ -12,25 +12,69 @@
 #  * LUA_INCLUDES (can be appended to CFLAGS directly)
 #  * LUA (full path to lua interpreter)
 #  * LUAC (full path to lua compiler)
+#
+# If unsuccessful, you can set these manually.
+
+ifndef LUA
+
+# first off, some helper functions to $(call) - this one executes lua/luac to match it's version
+lua_ver_match_bin = $(shell $2 -v 2>&1 | grep -qFo $1. && echo 1)
+# this one is like which(1), which isn't portable - from the gmake manual
+pathsearch = $(firstword $(wildcard $(addsuffix /$(1),$(subst :, ,$(PATH)))))
+# Extract "5.x" from lua -v
+lua_ver_extract = $(shell $1 -v 2>&1 | cut -f2 -d' ' | cut -f-2 -d.)
+
+# Lua does not provide an official .pc file, so finding one at all is tricky,
+# and there won't be any guarantees it looks the same as elsewhere.
+# We try the package names lua$(ver), lua-$(ver) for all candidate versions in
+# descending order and last but not least "lua" here.
+PKG_CONFIG_ALL_PACKAGES:= $(shell pkg-config --list-all | cut -f1 -d' ')
+
+# these are in order of preference
+LUA_CANDIDATES:=		$(or $(LUA_VERSION),5.3 5.2 5.1)
+LUA_BIN_CANDIDATES:=		$(foreach ver,$(LUA_CANDIDATES),lua$(ver) lua-$(ver))
+LUAC_BIN_CANDIDATES:=		$(foreach ver,$(LUA_CANDIDATES),luac$(ver) luac-$(ver))
+
+# the binaries might of course also just be called lua and luac
+ifndef LUA_VERSION
+LUA_BIN_CANDIDATES+=		lua
+LUAC_BIN_CANDIDATES+=		luac
+endif
 
-LUA_VERSIONS_CANDIDATES = $(or $(LUA_VERSION),5.3 5.2 5.1 5.0)
+# find pkg-config packages in the same order of preference
+PKG_CONFIG_LUA_PACKAGES:= 	$(foreach lua,$(LUA_BIN_CANDIDATES),$(filter $(lua),$(PKG_CONFIG_ALL_PACKAGES)))
+PKG_CONFIG_LUA:=		$(firstword $(PKG_CONFIG_LUA_PACKAGES))
 
-LUA_PKG := $(firstword $(foreach ver,$(LUA_VERSIONS_CANDIDATES),$(shell \
-       ($(PKG_CONFIG) --exists lua-$(ver)     && echo lua-$(ver)) \
-    || ($(PKG_CONFIG) --exists lua$(ver:5.0=) && echo lua$(ver:5.0=)))))
+ifeq ($(PKG_CONFIG_LUA),)
+$(error It seems that pkg-config is not aware of your lua package. Make sure \
+	the -dev package is installed along with a .pc file within the       \
+	pkg-config search-path. Alternatively, you can set the following     \
+	variables manually: LUA LUAC LUA_VERSION LUA_LIBS LUA_INCLUDES)
+endif
+
+PKG_CONFIG_LUA_VERSION:=	$(shell pkg-config --modversion $(PKG_CONFIG_LUA) | cut -d. -f-2)
+
+$(info >> pkg-config found Lua $(PKG_CONFIG_LUA_VERSION) (available: $(PKG_CONFIG_LUA_PACKAGES:=)).)
+
+LUA_LIBS=	$(shell pkg-config --libs $(PKG_CONFIG_LUA))
+LUA_INCLUDES=	$(shell pkg-config --cflags $(PKG_CONFIG_LUA))
+LUA_VERSION?=	$(PKG_CONFIG_LUA_VERSION)
 
-ifeq ($(LUA_PKG),)
-    $(error Could not find $(or $(LUA_VERSION),any) lua version. (Did you install the -dev package?))
+LUA=		$(firstword $(foreach bin,$(LUA_BIN_CANDIDATES),$(call pathsearch,$(bin))))
+LUAC=		$(firstword $(foreach bin,$(LUAC_BIN_CANDIDATES),$(call pathsearch,$(bin))))
+
+$(info >> Lua $(LUA_VERSION) binary is $(LUA) and luac is $(LUAC))
+
+ifneq ($(call lua_ver_match_bin,$(LUA_VERSION),$(LUA)),1)
+$(error $(LUA) should be $(LUA_VERSION) but is $(call lua_ver_extract,$(LUA)))
 endif
 
-ifeq ($(LUA_VERSION),)
-LUA_VERSION := $(or $(shell $(PKG_CONFIG) --variable=V $(LUA_PKG)),$(or $(shell $(PKG_CONFIG) --variable=major_version $(LUA_PKG)),5.0))
+ifneq ($(call lua_ver_match_bin,$(LUA_VERSION),$(LUAC)),1)
+$(error $(LUAC) should be $(LUA_VERSION) but is $(call lua_ver_extract,$(LUAC)))
 endif
 
-# prior to 5.1 the lib didn't include version in name.
-LUA_SUFFIX := $(if $(findstring $(LUA_VERSION),5.0),,$(LUA_VERSION))
+endif
 
-LUA_LIBS     := $(or $(shell $(PKG_CONFIG) --libs $(LUA_PKG)), $(error "pkg-config couldn't find linker flags for lua$(LUA_SUFFIX)!"))
-LUA_INCLUDES := $(shell $(PKG_CONFIG) --cflags $(LUA_PKG))
-LUA          := $(or $(shell which lua$(LUA_SUFFIX)),          $(shell which lua),  $(error No lua$(LUA_SUFFIX) interpreter found!))
-LUAC         := $(or $(shell which luac$(LUA_SUFFIX)),         $(shell which luac), $(error No lua$(LUA_SUFFIX) compiler found!))
+# this is necessary, otherwise the rest of the build process keeps calling
+# pkg-config and all these other programs up there
+export LUA_VERSION LUA_INCLUDES LUA_LIBS LUA LUAC

build/mkman.lua

@@ -10,8 +10,6 @@
 
 local translations={}
 
-local unpack = unpack or table.unpack
-
 local function gettext(x)
     local t=translations[x]
     if not t or t=="" then
@@ -22,7 +20,7 @@ local function gettext(x)
 end
 
 local function TR(x, ...)
-    return string.format(gettext(x), unpack(arg))
+    return string.format(gettext(x), ...)
 end
 
 local function read_translations(pofile)

ioncore/ioncore_misc.lua

@@ -17,8 +17,6 @@ local layouts={
     default = empty,
 }
 
-local unpack = unpack or table.unpack
-
 --DOC
 -- Define a new workspace layout with name \var{name}, and
 -- attach/creation parameters given in \var{tab}. The layout
@@ -75,8 +73,7 @@ end
 --DOC
 -- gettext+string.format
 function ioncore.TR(s, ...)
-    local arg = {...}
-    return string.format(ioncore.gettext(s), unpack(arg))
+    return string.format(ioncore.gettext(s), ...)
 end
 
 

libtu/Makefile

@@ -16,7 +16,7 @@ include $(TOPDIR)/build/system-inc.mk
 
 #INCLUDES += $(LIBTU_INCLUDES) $(LUA_INCLUDES)
 
-CFLAGS += $(C98_SOURCE) $(POSIX_SOURCE) $(WARN)
+CFLAGS += $(C89_SOURCE) $(POSIX_SOURCE) $(WARN)
 
 SOURCES=iterable.c  map.c  misc.c  obj.c  objlist.c  optparser.c  output.c  parser.c  prefix.c  ptrlist.c  rb.c  setparam.c  stringstore.c  tokenizer.c  util.c errorlog.c
 
@@ -47,4 +47,4 @@ install:
 	done
 
 test:
-	$(MAKE) -C test test
+	$(MAKE) -C test test

mod_query/mod_query.lua

@@ -1015,6 +1015,7 @@ function mod_query.do_handle_lua(mplex, env, code)
     local print_res
     local function collect_print(...)
         local tmp=""
+        local arg={...}
         local l=#arg
         for i=1,l do
             tmp=tmp..tostring(arg[i])..(i==l and "\n" or "\t")

mod_statusbar/ion-statusd/statusd_mail.lua

@@ -19,12 +19,10 @@ local defaults={
     files = {}
 }
 
-local unpack = unpack or table.unpack
-
 local settings=table.join(statusd.get_config(mon), defaults)
 
 local function TR(s, ...)
-    return string.format(statusd.gettext(s), unpack(arg))
+    return string.format(statusd.gettext(s), ...)
 end
 
 local function check_spool()