https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85857
Bug ID: 85857
Summary: configure problem using local mpfr and gmp
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: seurer at gcc dot gnu.org
Target Milestone: ---
There is a problem with configure if you use a local copy of mpfr and gmp
(grabbed via contrib/download_prerequisites) and then use
--enable-decimal-float on the configure for gcc itself. It occurs in gcc 7 as
well as in trunk (didn't try 6 or 8 but probably there, too).
$ $GCC_SRC/configure --prefix=$GCC_INSTALL --enable-languages=c,fortran,c++
--disable-bootstrap --disable-multilib --enable-decimal-float
$ make
. . .
configure: error: decimal float support requires --with-gmp-build
make[1]: *** [configure-mpfr] Error 1
I ran into this on a powerpc64 system but have duplicated it on an x86 system.
Adding --with-gmp-build as suggested doesn't work, either:
configure: error: in `/home/seurer/gcc/build/gcc-test/mpfr':
configure: error: Do not use --with-gmp-build and other --with-gmp options
simultaneously.
make[1]: *** [configure-mpfr] Error 1
Details from the config.log for mpfr:
$ cat mpfr/config.log
. . .
$ /home/seurer/gcc/gcc-test/mpfr/configure
--srcdir=/home/seurer/gcc/gcc-test/mpfr --cache-file=./config.cache
--prefix=/home/seurer/gcc/install/gcc-test --disable-bootstrap
--disable-multilib --enable-decimal-float --enable-languages=c,c++,fortran,lto
--program-transform-name=s,y,y, --disable-option-checking
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --disable-shared
--with-gmp-include=/home/seurer/gcc/build/gcc-test/./gmp
--with-gmp-lib=/home/seurer/gcc/build/gcc-test/./gmp/.libs
. . .
configure:5164: checking if compiler knows _Decimal64
configure:5177: /usr/bin/gcc -c -g -O2 -I/home/seurer/gcc/build/gcc-test/gmp
conftest.c >&5
configure:5177: $? = 0
configure:5178: result: yes
configure:5181: error: decimal float support requires --with-gmp-build
