Re: objc/6834: gcc 3.1 wrongly compiles some GNUstep code

Re: objc/6834: gcc 3.1 wrongly compiles some GNUstep code

[sayle]

Synopsis: gcc 3.1 wrongly compiles some GNUstep code

State-Changed-From-To: open->closed
State-Changed-By: sayle
State-Changed-When: Thu Jun 27 20:19:24 2002
State-Changed-Why:
    This PR has recently been fixed both on the branch and on
    mainline by Nicola Pero's June 6th patch:
    
    Thu Jun  6 07:17:43 2002  Nicola Pero  <n.pero@mi.flashnet.it>
    
            PR objc/6834
            * objc/objc-lang.c (LANG_HOOKS_GET_ALIAS_SET): Define to be
            c_common_get_alias_set.
            (LANG_HOOKS_SAFE_FROM_P): Define to be c_safe_from_p.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6834

objc/6834: gcc 3.1 wrongly compiles some GNUstep code

[benhur]

>Number:         6834
>Category:       objc
>Synopsis:       gcc 3.1 wrongly compiles some GNUstep code
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Mon May 27 07:56:02 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Benhur Stein
>Release:        gcc version 3.1
>Organization:
>Environment:
Linux (gentoo 1a, 2.4.18), Pentium III
>Description:
This is the code to swap bytes in a 2-byte integer, existing
in GNUstep. The generated code converts 0x0456 into 0x0408
instead of 0x5604. The same file, renamed from y.m to y.c
generates good code. This used to work in gcc 3.0.4.
Without -O2, the code compiles OK.

Compiler output:
bash-2.05a$ gcc -v -save-temps -O2 y.m
Reading specs from /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
Configured with: /var/tmp/portage/gcc-3.1-r2/work/gcc-3.1/configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share/gcc-3.1 --enable-shared --host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --target=i686-pc-linux-gnu --enable-threads=posix --disable-checking --with-local-prefix=/usr/local --with-system-zlib --enable-shared --enable-nls --without-included-gettext
Thread model: posix
gcc version 3.1
 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/cpp0 -lang-objc -v -D__GNUC__=3 -D__GNUC_MINOR__=1 -D__GNUC_PATCHLEVEL__=0 -D__ELF__ -Dunix -D__gnu_linux__ -Dlinux -D__ELF__ -D__unix__ -D__gnu_linux__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__OPTIMIZE__ -D__STDC_HOSTED__=1 -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i686__ -D__tune_pentiumpro__ y.m y.mi
GNU CPP version 3.1 (cpplib) (i386 Linux/ELF)
ignoring nonexistent directory "/usr/i686-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/include
 /usr/include
End of search list.
 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/cc1obj -fpreprocessed y.mi -quiet -dumpbase y.m -O2 -version -o y.s
GNU CPP version 3.1 (cpplib) (i386 Linux/ELF)
GNU Objective-C version 3.1 (i686-pc-linux-gnu)
        compiled by GNU C version 3.1.
 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/../../../../i686-pc-linux-gnu/bin/as -V -Qy -o y.o y.s
GNU assembler version 2.11.92.0.12.3 (i686-pc-linux-gnu) using BFD version 2.11.92.0.12.3 20011121
 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/collect2 -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/../../../crt1.o /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/../../../crti.o /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/crtbegin.o -L/usr/lib/gcc-lib/i686-pc-linux-gnu/3.1 -L/usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/../../../../i686-pc-linux-gnu/lib -L/usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/../../.. y.o -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/crtend.o /usr/lib/gcc-lib/i686-pc-linux-gnu/3.1/../../../crtn.o
bash-2.05a$ 
>How-To-Repeat:
gcc -O2 y.mi
./a.out
prints 456 408 (0x456 is input and 0x408 is output to the function)

mv y.mi y.i
gcc -O2 y.i
./a.out
prints 456 5604  (the correct output)
>Fix:
compile without -O2;
put a call to a bogus function in the beginning of the  GSSwapI16 function.
>Release-Note:
>Audit-Trail:
>Unformatted:
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