AC_LINK_IFELSE unexpectedly fails on Ubuntu 12.04
Hi ,
When running the configure script for OpenJDK on Ubuntu 12.04, the
'checking if we can compile and link with freetype...' check fails
unexpectedly ...
$ sh ./configure --with-jdk-variant=ibm
--with-import-hotspot=../../SVN/sdk80 --enable-openjdk-only
--with-freetype-lib=/usr/lib/i386-linux-gnu
--with-freetype-include=/usr/include
.
.
configure: Found freetype include files at /usr/include using
--with-freetype
checking for freetype includes... /usr/include
checking for freetype libraries... /usr/lib/i386-linux-gnu
checking if we can compile and link with freetype... no
configure: Could not compile and link with freetype. This might be a
32/64-bit mismatch.
configure: Using FREETYPE_CFLAGS=-I/usr/include/freetype2 -I/usr/include
and FREETYPE_LIBS=-L/usr/lib/i386-linux-gnu -lfreetype
configure: error: Can not continue without freetype.
configure exiting with result code 1
$
The above confirms that the freetype headers have, but interestingly not
the libraries have not, been found. Inspection of the build log reveals
the following command to have been run:
configure:34201: /usr/bin/g++-4.6 -o conftest -I/usr/include/freetype2
-I/usr/include -L/usr/lib/i386-linux-gnu -lfreetype conftest.cpp 5
against the conftest code. The problem can be readily simplified viz -
given a copy of the conftest file, in t.c, containing ...
$ cat t.c
#includeft2build.h
#include FT_FREETYPE_H
int main () {
FT_Init_FreeType(NULL);
return 0;
}
$
... the following commands and their results are all observed ...
$ compiler t.c `freetype-config --cflags` `freetype-config --libs`
$ compiler `freetype-config --cflags` t.c `freetype-config --libs`
$ compiler `freetype-config --cflags` `freetype-config --libs` t.c
/tmp/ccCTZzpt.o: In function `main':
t.c:(.text+0x11): undefined reference to `FT_Init_FreeType'
collect2: ld returned 1 exit status
$
where the same results are observed whether compileris cc, gcc or g++.
Thus it will be seen that, unlike the gcc of old, the ordering of the
options to the compiler is of paramount importance on Ubuntu - the linker
option(s) must be specified after the source source file and any CFLAGS.
I have repeated the exercise on Solaris 10, AIX 7.1 RHEL 6 - on none of
which is the problem prevalent i.e. the command line options can be
specified in any order resulting in a.out being successfully generated.
As configure failed, running make check is not possible since there is no
Makefile.
Rgds ,
--
Dave Pointon FIAP MBCS | Now I saw, tho' too late, the folly of beginning
a work before we
Test/Software Engineer | count the cost and before we we judge
rightly of our strength to
| go thro' with it - Robinson
Crusoe
Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number
741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
Re: AC_LINK_IFELSE unexpectedly fails on Ubuntu 12.04
Hiya Paul , AFAICT, the problem stems from a generated shell function called ac_fn_cxx_try_link but there's no trace of that in any of the OJDK scripts other than in generated-configure.sh - for which there's no provenance, hence I inferred that it came from within autoconf ... but of course, I could be wrong ;-/ Rgds , -- Dave Pointon FIAP MBCS | Now I saw, tho' too late, the folly of beginning a work before we Test/Software Engineer | count the cost and before we we judge rightly of our strength to | go thro' with it - Robinson Crusoe From: Paul Eggert egg...@cs.ucla.edu To: David Pointon/UK/Contr/IBM@IBMGB, bug-autoconf@gnu.org, Cc: david.poin...@unix.net Date: 25/10/2013 15:46 Subject:Re: AC_LINK_IFELSE unexpectedly fails on Ubuntu 12.04 This would appear to be a problem in OpenJDK's configure.ac file, not in Autoconf itself, no? So you should send a bug report to the OpenJDK folks. Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
Re: AC_LINK_IFELSE unexpectedly fails on Ubuntu 12.04
David Pointon wrote: AFAICT, the problem stems from a generated shell function called ac_fn_cxx_try_link Sure, but that function depends on the appropriate -L, -I, -l, etc. options being set appropriately for your system, and if those options are messed up than that function won't work. It appears that the options are messed up somehow. Most likely it's OpenJDK since we aren't observing the problem with other packages that use Autoconf. It's of course possible that it is an Autoconf bug but we'll need someone to debug the script in question to determine that, and most likely that'll have to be someone with OpenJDK build expertise.
Re: AC_LINK_IFELSE unexpectedly fails on Ubuntu 12.04
David Pointon dpoin...@uk.ibm.com writes: The above confirms that the freetype headers have, but interestingly not the libraries have not, been found. Inspection of the build log reveals the following command to have been run: configure:34201: /usr/bin/g++-4.6 -o conftest -I/usr/include/freetype2 -I/usr/include -L/usr/lib/i386-linux-gnu -lfreetype conftest.cpp 5 The contents of $FREETYPE_LIBS are being put on the compilation command line before the program to be compiled instead of afterwards. This has never been guaranteed to work. Some linkers dynamically reorder the link line and cause this to work, but you can't rely on that behavior, and it stopped working in the versions of the toolchain currently in Ubuntu. I suspect somewhere in the configure machinery for this package, something is adding $FREETYPE_LIBS to $LDFLAGS. This is wrong. $LDFLAGS and $LIBS are intentionally separate, and $LIBS flags cannot go into $LDFLAGS for exactly this reason. Compilers and linkers are generally more forgiving about the location of the -L flags, so putting $LDFLAGS flags into $LIBS will usually work if there's no way to get properly separated $LDFLAGS and $LIBS variables, which may be the case here. Short version: If I'm right, find where the configure script is throwing $FREETYPE_LIBS into $LDFLAGS and change it to add those flags to $LIBS instead. -- Russ Allbery (r...@stanford.edu) http://www.eyrie.org/~eagle/
