Bug #10710
closedcan't compile ruby 2.2.0 with gcc versions older than 4.4.0
Description
compilation stops because gcc before 4.4.0 does not support the flag -Wno-packed-bitfield-compat.
patch can be found here: https://github.com/skaes/rvm-patchsets/blob/master/patches/ruby/2.2.0/railsexpress/05-fix-packed-bitfield-compat-warning-for-older-gccs.patch
Files
Updated by normalperson (Eric Wong) almost 10 years ago
stkaes@googlemail.com wrote:
compilation stops because gcc before 4.4.0 does not support the flag
-Wno-packed-bitfield-compat.
I'm curious what error you saw. An ancient CentOS 5.4 x86-64 machine
managed to build it using: gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-46)
--- a/configure.in
+++ b/configure.in
@@ -788,6 +788,9 @@ rb_cv_warnflags="$warnflags"
if test "$GCC:${warnflags+set}:no" = yes::no; then
if test $gcc_major -ge 4; then
extra_warning=-Werror=extra-tokens
+ if test $gcc_major -gt 4 -o $gcc_minor -ge 4; then
+ extra_warning="$extra_warning -Wno-packed-bitfield-compat"
+ fi
I think "||" is preferable to "-o" for portability. But maybe not a
problem nowadays...
Updated by drkaes (Stefan Kaes) almost 10 years ago
$ gcc --version
gcc (Debian 4.3.2-1.1) 4.3.2
The compilation of a given source file fails as soon as the compiler needs to emit some warning:
gcc -Wno-packed-bitfield-compat some_warning.c
some_warning.c: In function ‘main’:
some_warning.c:3: warning: return type of ‘main’ is not ‘int’
At top level:
cc1: error: unrecognized command line option "-Wno-packed-bitfield-compat"
Updated by normalperson (Eric Wong) almost 10 years ago
The compilation of a given source file fails as soon as the compiler
needs to emit some warning:
Right, but ./configure detects that failure, disables the
-Wno-packed-bitfield-compat switch, and the rest of the build continues
without it, right?
Updated by drkaes (Stefan Kaes) almost 10 years ago
no. it aborts the build.
Updated by nobu (Nobuyoshi Nakada) almost 10 years ago
- Status changed from Open to Feedback
Could you show your config.log file, around checking -Wno-packed-bitfield-compat
?
Updated by drkaes (Stefan Kaes) almost 10 years ago
the problem is that the compiler accepts the warning flag but fails to compile a piece of code as soon as it tries to emit some warning.
configure:7495: checking whether -Wno-packed-bitfield-compat is accepted as CFLAGS
configure:7518: gcc -c -g -O2 -Wno-packed-bitfield-compat conftest.c >&5
configure:7518: $? = 0
configure:7533: result: yes
Updated by drkaes (Stefan Kaes) almost 10 years ago
here's the build output:
~/src/ruby-2.2.0 $ make
CC = gcc
LD = ld
LDSHARED = gcc -shared
CFLAGS = -O3 -fno-fast-math -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wunused-variable -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration -Wdeprecated-declarations -Wno-packed-bitfield-compat -std=iso9899:1999 -fPIC
XCFLAGS = -D_FORTIFY_SOURCE=2 -fstack-protector -fno-strict-overflow -fvisibility=hidden -DRUBY_EXPORT
CPPFLAGS = -I. -I.ext/include/x86_64-linux -I./include -I.
DLDFLAGS = -Wl,-soname,libruby.so.2.2 -fstack-protector
SOLIBS = -lpthread -lrt -lgmp -ldl -lcrypt -lm
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.3.2-1.1' --with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3 --program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr --enable-cld --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.3.2 (Debian 4.3.2-1.1)
compiling main.c
compiling dmydln.c
compiling miniinit.c
compiling miniprelude.c
copying dummy probes.h
compiling array.c
compiling bignum.c
bignum.c: In function ‘rb_absint_numwords’:
bignum.c:3370: warning: ‘nlz_bits’ may be used uninitialized in this function
At top level:
cc1: error: unrecognized command line option "-Wno-packed-bitfield-compat"
make: *** [bignum.o] Error 1
Updated by drkaes (Stefan Kaes) almost 7 years ago
- Status changed from Feedback to Closed
no longer relevant