Trying to cross build a native compiler for arm-linux on x86_64 linux currently
fails to build, if the libgmp development files are not available for the build
system. This works with 4.7, but fails with 4.8.
The build fails with:
TARGET_CPU_DEFAULT="" \
HEADERS="auto-build.h ansidecl.h" DEFINES="" \
/bin/bash ../../src/gcc/mkconfig.sh bconfig.h
g++ -c -g -O2 -DIN_GCC -fno-exceptions -fno-rtti
-fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual
-Wmissing-format-attribute -pedantic -Wno-long-long -Wno-variadic-macros
-Wno-overlength-strings -DHAVE_CONFIG_H -DGENERATOR_FILE -I. -Ibuild
-I../../src/gcc -I../../src/gcc/build -I../../src/gcc/../include
-I../../src/gcc/../libcpp/include -I../../src/gcc/../libdecnumber
-I../../src/gcc/../libdecnumber/dpd -I../libdecnumber
-I../../src/gcc/../libbacktrace -DCLOOG_INT_GMP \
-o build/genconstants.o ../../src/gcc/genconstants.c
In file included from /usr/include/x86_64-linux-gnu/sys/resource.h:25:0,
from ../../src/gcc/system.h:395,
from ../../src/gcc/genconstants.c:28:
/usr/include/x86_64-linux-gnu/bits/resource.h:131:18: error: declaration does
not declare anything [-fpermissive]
In file included from ../../src/gcc/genconstants.c:28:0:
../../src/gcc/system.h:444:23: error: declaration of C function 'void*
sbrk(int)' conflicts with
Searching the archive and ML this is supposed to work according to
PR 35051, as described in
http://gcc.gnu.org/ml/gcc-patches/2008-02/msg00041.html
When building the auto-build.h, all the configure tests including the system.h
header fail to build with
configure:10361: gcc -c -I../../../src/gcc -I../../../src/gcc/../include
conftest.c >&5
In file included from ../../../src/gcc/system.h:641:0,
from conftest.c:116:
/usr/include/gmp.h:69:24: fatal error: gmp-x86_64.h: No such file or directory
compilation terminated.
And at least all the HAVE_DECL_* defines are set to 0 instead of 1.
[side note: can we keep the temporary directory for this? it's a bit
strange that this directory is removed during the build, and can't
be looked at. The build continues after the configure, and then
fails later]
I checked that defining GENERATOR_FILE for this configure step to build the
auto-build.h lets me to cross build the native compiler, and the resulting build
seems to work on the target platform. However I can't find any other
documentation for GENERATOR_FILE, so I'm unsure if that's the right thing to do.
Richard did introduce the conditional include of gmp.h based on GENERATOR_FILE
back in 2008, and Steven did define this for some object files built for the
host, but not the build in 2012:
2012-07-08 Steven Bosscher <ste...@gcc.gnu.org>
* Makefile.in (gengtype-lex.o, gengtype-parse.o, gengtype-state.o,
gengtype.o): Add -DGENERATOR_FILE manually for host gengtype objects.
Is just setting _DGENERATOR_FILE for the auto-build.h build the right thing to
do? If yes, ok for the 4.8 branch and the trunk? I didn't yet figure out why
this works with 4.7.
Matthias
--- gcc/configure.ac~ 2013-06-11 18:34:36.757067080 +0200
+++ gcc/configure.ac 2013-06-11 22:51:47.340892778 +0200
@@ -1519,7 +1519,7 @@
*) realsrcdir=../${srcdir};;
esac
saved_CFLAGS="${CFLAGS}"
- CC="${CC_FOR_BUILD}" CFLAGS="${CFLAGS_FOR_BUILD}" \
+ CC="${CC_FOR_BUILD}" CFLAGS="${CFLAGS_FOR_BUILD} -DGENERATOR_FILE" \
LDFLAGS="${LDFLAGS_FOR_BUILD}" \
${realsrcdir}/configure \
--enable-languages=${enable_languages-all} \
