Re: 32-bit buildbot builders broken [Re: Your commit 'Build GDB as a C++ program by default' broke GDB]

[Antoine Tremblay <antoine dot tremblay at ericsson dot com>]

Sergio Durigan Junior writes:

> On Thursday, April 21 2016, Pedro Alves wrote:
>
>>> g++ -g -O2   -I. -I../../binutils-gdb/gdb -I../../binutils-gdb/gdb/common
>>> -I../../binutils-gdb/gdb/config
>> ...
>>> -I../../binutils-gdb/gdb/../libdecnumber
>>> -I../../binutils-gdb/gdb/gnulib/import -Ibuild-gnulib/import -DTUI=1
>>> -I/usr/include/python2.7 -I/usr/include/python2.7 -Wall
>>> -Wpointer-arith -Wno-unused -Wunused-value -Wunused-function
>>> -Wno-switch -Wno-char-subscripts -Wempty-body -Wno-sign-compare
>>> -Wno-write-strings -Wno-narrowing -Wformat-nonliteral -Werror -c -o
>>> linux-thread-db.o -MT linux-thread-db.o -MMD -MP -MF
>>> .deps/linux-thread-db.Tpo ../../binutils-gdb/gdb/linux-thread-db.c
>>> In file included from ../../binutils-gdb/gdb/i386-linux-nat.c:25:0:
>>> ../../binutils-gdb/gdb/i386-linux-nat.c: In function void fetch_regs(regcache*, int):
>>> ../../binutils-gdb/gdb/i386-linux-nat.c:207:46: error: cast from elf_greg_t (*)[27] {aka long long unsigned int (*)[27]} to int loses precision [-fpermissive]
>>>    if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
>>
>>
>> ... however this error is exactly what you get if you compile with a
>> 64-bit compiler, and forget to pass -m32 to gcc/g++.  IOW, 
>> it compiles i386-linux-nat.c as if for a 64-bit host, which fails.
>>
>> So I suspect the builder is using CC="gcc -m32", and now that a C++ compiler
>> is involved, it needs to be updated to pass CXX="g++ -m32" as well.
>
> Yeah, actually I was setting CFLAGS without setting CXXFLAGS for these
> builders, so I fixed that now.  Thanks for letting me know, and sorry
> about that.

I was looking at
http://gdb-build.sergiodj.net/builders/Fedora-x86_64-m32/builds/3499/steps/configure%20gdb/logs/stdio

And it seems it builds in 64 bit, there's no --host=i386... or -m32 ?

Thanks,
Antoine