!
! First of all, my appologies for the 2 month delay. I've been slow.
Appologies accepted :)
Also you were faster to reverse the patch than I was able to defend my
point of view.
!
! I appricate your patch, but I think maybe you misunderstood the function of
! AX_LUA_HEADERS.
Whatever it means, ax_lua.m4 in some cases is broken and my goal was to improve it.
!
! This macro was not written to search /usr/include. All Lua distributions
! (rightfully) put their headers in a subdirectory with a version number. Could
! you please tell me more about your system, specifically why it is putting
! lua.h in /usr/include?
If Lua distributions put their headers in subdirectory, this doesn't mean that
all source packages around that use lua in their code will follow that convention.
Some will even bundle lua and make things worse.
For instance, dnsmasq 2.72 and nginx module ngx_http_lua_module don't follow
that convention.
ngx_http_lua_module will return an error like that:
checking for Lua library in /usr/lib64 and /usr/include/ (specified by the LUA_LIB and LUA_INC env) ... not found
./configure: error: ngx_http_lua_module requires the Lua or LuaJIT library and LUA_LIB is defined as /usr/lib64 and LUA_INC (path for lua.h) is /usr/include/, but we cannot find standard Lua there.
For portability, /usr/include, /usr/lib /usr/bin are to be always the default
and are relevant if you don't care about revisions.
But I won't fight you for that :)
I'm using a meta distribution (GENTOO) and it is common to compile (on the fly)
more than 50 sources per day.
Patching every source is a pain when it comes to so many upgrades per day.
And if a patch is needed, it is actually better to modify a few lines in a
configure.ac and to hope that the patch will be included in the next release by
the maintainer.
! Your change to the search is only neccessary because you added /usr/include to
! the search list, and there is no version number in the path. Really, I think
! you should have just set the appropriate environment variables, like
! LUA_INCLUDE, which are well documented.
As said earlier, the issue isn't limited to lua include files.
Anyway, if LUA_INCLUDE were the solution, I wouldn't spend my (precious and
limited) time to patch :)
! I don't think this should have been a code change. The previous code was well
! tested, and sorry but I'm not convienced of the testing on this patch. In
! fact, it has some issues.
!
! So I recommend a revert.
!
! P.S. The "(cached)" is because you removed the unsets, and AC_CHECK_HEADERS is
! finding the cached results from the last loop iteration. I'm guessing that was
! a mistake.
Before taking such a decision, please consider the following:
The issue can be illustrated with a real example: dev-lua/luaposix-5.1.28
You can find it under https://github.com/luaposix/luaposix/archive/release.zip
Prerequisite:
# ls -l /usr/include | grep lua
lrwxrwxrwx 1 root root 29 13 août 01:01 lauxlib.h -> /usr/include/lua5.1/lauxlib.h
drwxr-xr-x 2 root root 4096 12 août 23:55 lua5.1
drwxr-xr-x 2 root root 4096 12 août 18:08 lua5.2
lrwxrwxrwx 1 root root 29 13 août 01:01 luaconf.h -> /usr/include/lua5.1 luaconf.h
lrwxrwxrwx 1 root root 25 13 août 01:01 lua.h -> /usr/include/lua5.1/lua.h
lrwxrwxrwx 1 root root 27 13 août 01:01 lua.hpp -> /usr/include/lua5.1/lua.hpp
lrwxrwxrwx 1 root root 28 13 août 01:01 lualib.h -> /usr/include/lua5.1/lualib.h
To begin you could test posixlua w/ its original configure and ax_lua.m4 file.
As expected, it will fail if you change AX_PROG_LUA(5.1, 5.3) to
AX_PROG_LUA(5.2, 5.3).
The issue affects lua's library and interpreter as well.
Solution:
I just care about configure, configure.ac and ax_lua.m4 patched.
To use efficiently the patch you need to alter the configure.ac file as follows:
# cd luaposix-release
# diff -ruN configure.ac.ori configure.ac
--- configure.ac.old 2014-12-10 16:18:05.694407443 +0100
+++ configure.ac 2014-12-10 16:23:24.700602738 +0100
@@ -1,3 +1,5 @@
+m4_define([LUA_PREREQ],5.2.0)
+
dnl configure.ac
dnl Written by Gary V. Vaughan, 2012
@@ -13,6 +15,8 @@
AS_BOX([Configuring AC_PACKAGE_TARNAME AC_PACKAGE_VERSION])
echo
+PKG_CHECK_MODULES([LUA], [lua5.2 >= 5.2])
+
AM_INIT_AUTOMAKE([-Wall subdir-objects])
m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
@@ -121,7 +125,9 @@
LIBS=$save_LIBS
dnl Lua 5.1 or 5.2
-AX_PROG_LUA(5.2, 5.3)
+dnl AX_PROG_LUA(5.2, 5.3)
+AX_PROG_LUA(LUA_PREREQ)
+AX_LUA_LIBS
AX_LUA_HEADERS
AC_PATH_PROG([SPECL], [specl], [:])
the additions are quite trivial.
# autoconf
# ./configure
The configure script will now succeed and output,
# ./configure
## ----------------------- ##
## Configuring luaposix 32 ##
## ----------------------- ##
checking for pkg-config... /usr/bin/pkg-config
checking pkg-config is at least version 0.9.0... yes
checking for LUA... yes
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking whether make supports nested variables... (cached) yes
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking whether gcc understands -c and -o together... yes
checking for style of include used by make... GNU
checking dependency style of gcc... gcc3
checking how to run the C preprocessor... gcc -E
checking for grep that handles long lines and -e... /bin/grep
checking for egrep... /bin/grep -E
checking for Minix Amsterdam compiler... no
checking for ar... ar
checking for ranlib... ranlib
checking for egrep... (cached) /bin/grep -E
checking for a sed that does not truncate output... /bin/sed
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking minix/config.h usability... no
checking minix/config.h presence... no
checking for minix/config.h... no
checking whether it is safe to define __EXTENSIONS__... yes
checking the archiver (ar) interface... ar
checking build system type... x86_64-unknown-linux-gnu
checking host system type... x86_64-unknown-linux-gnu
checking how to print strings... print -r
checking for a sed that does not truncate output... (cached) /bin/sed
checking for fgrep... /bin/grep -F
checking for ld used by gcc... /usr/x86_64-pc-linux-gnu/bin/ld
checking if the linker (/usr/x86_64-pc-linux-gnu/bin/ld) is GNU ld... yes
checking for BSD- or MS-compatible name lister (nm)... /usr/bin/nm -B
checking the name lister (/usr/bin/nm -B) interface... BSD nm
checking whether ln -s works... yes
checking the maximum length of command line arguments... 1572864
checking whether the shell understands some XSI constructs... yes
checking whether the shell understands "+="... yes
checking how to convert x86_64-unknown-linux-gnu file names to x86_64-unknown-linux-gnu format... func_convert_file_noop
checking how to convert x86_64-unknown-linux-gnu file names to toolchain format... func_convert_file_noop
checking for /usr/x86_64-pc-linux-gnu/bin/ld option to reload object files... -r
checking for objdump... objdump
checking how to recognize dependent libraries... pass_all
checking for dlltool... no
checking how to associate runtime and link libraries... print -r --
checking for archiver @FILE support... @
checking for strip... strip
checking for ranlib... (cached) ranlib
checking command to parse /usr/bin/nm -B output from gcc object... ok
checking for sysroot... no
checking for mt... mt
checking if mt is a manifest tool... no
checking for dlfcn.h... yes
checking for objdir... .libs
checking if gcc supports -fno-rtti -fno-exceptions... no
checking for gcc option to produce PIC... -fPIC -DPIC
checking if gcc PIC flag -fPIC -DPIC works... yes
checking if gcc static flag -static works... yes
checking if gcc supports -c -o file.o... yes
checking if gcc supports -c -o file.o... (cached) yes
checking whether the gcc linker (/usr/x86_64-pc-linux-gnu/bin/ld -m elf_x86_64) supports shared libraries... yes
checking whether -lc should be explicitly linked in... no
checking dynamic linker characteristics... GNU/Linux ld.so
checking how to hardcode library paths into programs... immediate
checking whether stripping libraries is possible... yes
checking if libtool supports shared libraries... yes
checking whether to build shared libraries... yes
checking whether to build static libraries... no
checking for ANSI C header files... (cached) yes
checking crypt.h usability... yes
checking crypt.h presence... yes
checking for crypt.h... yes
checking for strings.h... (cached) yes
checking sys/statvfs.h usability... yes
checking sys/statvfs.h presence... yes
checking for sys/statvfs.h... yes
checking net/if.h usability... yes
checking net/if.h presence... yes
checking for net/if.h... yes
checking linux/netlink.h usability... yes
checking linux/netlink.h presence... yes
checking for linux/netlink.h... yes
checking for library containing crypt... -lcrypt
checking for strlcpy... no
checking for statvfs... yes
checking for posix_fadvise... yes
checking for NcursesW wide-character library... yes
checking for working ncursesw/curses.h... yes
checking for working ncursesw.h... no
checking for working ncurses.h... no
checking for resizeterm... yes
checking for a Lua interpreter with version >= 5.2.0... lua5.2
checking for lua5.2... /usr/bin/lua5.2
checking for lua5.2 version... 5.2
checking for lua5.2 platform... unknown
checking for lua5.2 script directory... ${prefix}/share/lua/5.2
checking for lua5.2 module directory... ${exec_prefix}/lib/lua/5.2
checking if LUA_VERSION is defined... yes
checking for library containing exp... -lm
checking for library containing dlopen... -ldl
checking for library containing lua_load... -llua5.2
checking if LUA_VERSION is defined... yes
checking lua.h usability... yes
checking lua.h presence... yes
checking for lua.h... yes
checking lualib.h usability... yes
checking lualib.h presence... yes
checking for lualib.h... yes
checking lauxlib.h usability... yes
checking lauxlib.h presence... yes
checking for lauxlib.h... yes
checking luaconf.h usability... yes
checking luaconf.h presence... yes
checking for luaconf.h... yes
checking if Lua header version 5.1 matches 5.2... no
checking for lua.h... (cached) yes
checking for lualib.h... (cached) yes
checking for lauxlib.h... (cached) yes
checking for luaconf.h... (cached) yes
checking if Lua header version 5.2 matches 5.2... yes
checking for specl... :
checking for perl... /usr/bin/perl
checking for ldoc... false
checking that generated files are newer than configure... done
configure: creating ./config.status
config.status: creating .travis.yml
config.status: creating Makefile
config.status: creating build-aux/config.ld
config.status: creating config.h
config.status: config.h is unchanged
config.status: executing depfiles commands
config.status: executing libtool commands
And as expected the configure script has succeeded.
The patch could be weak... but not meaningless.