Problem exception handling g++ 2.95.3-i686

[IT Staff]

Hello

We have got a problem with exception handling on a g++ 2.95.3
i686-linux-elf 
system.

In a given case, the compilator seems to mess up with the address of the 
objects when we get out of a function.

class EX:public TR,public SB

will be ok if we recover the exception as a TR
will crash if we recover the exception as a SB

We think it could be related to the stack frame difference in an
exception 
environment.

Any idea of how we could make this work correclty ?

In attachments, you have :
x.txt : dump of the correct behaviour.
y.txt : dump of the bugged behaviour.
extest.cpp : source code
dumpXXX.txt : dump of "g++ -dumpXXX"

Thanks in advance.

Regards,
IT Staff

i686-pc-linux-gnu

*asm:
%{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} %{Wa,*:%*}

*asm_final:
%|

*cpp:
%(cpp_cpu) %{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} 
%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}

*cc1:
%(cc1_cpu) %{profile:-p}

*cc1plus:


*endfile:
%{!shared:crtend.o%s} %{shared:crtendS.o%s} crtn.o%s

*link:
-m elf_i386 %{shared:-shared}   %{!shared:     %{!ibcs:       %{!static:        
%{rdynamic:-export-dynamic}     %{!dynamic-linker:-dynamic-linker 
/lib/ld-linux.so.2}}  %{static:-static}}}

*lib:
%{shared: -lc}    %{!shared: %{mieee-fp:-lieee} %{pthread:-lpthread}    
%{profile:-lc_p} %{!profile: -lc}}

*libgcc:
-lgcc

*startfile:
%{!shared:      %{pg:gcrt1.o%s} %{!pg:%{p:gcrt1.o%s}                   
%{!p:%{profile:gcrt1.o%s}                         %{!profile:crt1.o%s}}}}    
crti.o%s %{!shared:crtbegin.o%s} %{shared:crtbeginS.o%s}

*switches_need_spaces:


*signed_char:
%{funsigned-char:-D__CHAR_UNSIGNED__}

*predefines:
-D__ELF__ -Dunix -D__i386__ -Dlinux -Asystem(posix)

*cross_compile:
0

*version:
2.95.3

*multilib:
.. ;

*multilib_defaults:


*multilib_extra:


*multilib_matches:


*linker:
collect2

*cpp_486:
%{!ansi:-Di486} -D__i486 -D__i486__

*cpp_586:
%{!ansi:-Di586 -Dpentium}       -D__i586 -D__i586__ -D__pentium -D__pentium__

*cpp_k6:
%{!ansi:-Di586 -Dk6}    -D__i586 -D__i586__ -D__k6 -D__k6__

*cpp_686:
%{!ansi:-Di686 -Dpentiumpro}    -D__i686 -D__i686__ -D__pentiumpro 
-D__pentiumpro__

*cpp_cpu_default:
%(cpp_686)

*cpp_cpu:
-Acpu(i386) -Amachine(i386) %{!ansi:-Di386} -D__i386 -D__i386__ 
%{mcpu=i486:%(cpp_486)} %{m486:%(cpp_486)} %{mpentium:%(cpp_586)} 
%{mcpu=pentium:%(cpp_586)} %{mpentiumpro:%(cpp_686)} 
%{mcpu=pentiumpro:%(cpp_686)} %{mcpu=k6:%(cpp_k6)} 
%{!mcpu*:%{!m486:%{!mpentium*:%(cpp_cpu_default)}}}

*cc1_cpu:
%{!mcpu*: %{m386:-mcpu=i386 -march=i386} %{m486:-mcpu=i486 -march=i486} 
%{mpentium:-mcpu=pentium} %{mpentiumpro:-mcpu=pentiumpro}}

*link_command:
%{!fsyntax-only:  %{!c:%{!M:%{!MM:%{!E:%{!S:%(linker) %l %X %{o*} %{A} %{d} 
%{e*} %{m} %{N} %{n}                        %{r} %{s} %{t} %{u*} %{x} %{z} %{Z} 
                    %{!A:%{!nostdlib:%{!nostartfiles:%S}}}                  
%{static:} %{L*} %D %o                  %{!nostdlib:%{!nodefaultlibs:%G %L %G}} 
                %{!A:%{!nostdlib:%{!nostartfiles:%E}}}                  %{T*}   
                
 }}}}}}


2.95.3

test start
exception_test() begin
[bffff20c]::T()->
[bffff20c]::<-T()
[bffff1f0]::TR()->
[bffff1f0]::<-TR()
[bffff1fc]::SB()->
[bffff1fc]::<-SB()
[bffff1f0]::EX()->
[bffff1f0]::<-EX()
[081e0f14]::T()->
[081e0f14]::<-T()
[081e0ef8]::TR(x)->
[081e0ef8]::<-TR(x)
[081e0f04]::SB(x)->
[081e0f04]::<-SB(x)
[081e0ef8]::EX(x)->
[081e0ef8]::<-EX(x)
[bffff1f0]::~EX()->
[bffff1f0]::<-~EX()
[bffff1fc]::~SB()->
[bffff1fc]::<-~SB()
[bffff1f0]::~TR()->
[bffff1f0]::<-~TR()
[bffff20c]::~T()->
[bffff20c]::<-~T()
got the throw
[081e5b64]::T()->
[081e5b64]::<-T()
[081e5b48]::TR(x)->
[081e5b48]::<-TR(x)
[081e5b54]::SB(x)->
[081e5b54]::<-SB(x)
[081e5b48]::EX(x)->
[081e5b48]::<-EX(x)
[081e0ef8]::~EX()->
[081e0ef8]::<-~EX()
[081e0f04]::~SB()->
[081e0f04]::<-~SB()
[081e0ef8]::~TR()->
[081e0ef8]::<-~TR()
[081e0f14]::~T()->
[081e0f14]::<-~T()
got it
[081e5b48]::~EX()->
[081e5b48]::<-~EX()
[081e5b54]::~SB()->
[081e5b54]::<-~SB()
[081e5b48]::~TR()->
[081e5b48]::<-~TR()
[081e5b64]::~T()->
[081e5b64]::<-~T()
test done

test start
exception_test() begin
[bffff20c]::T()->
[bffff20c]::<-T()
[bffff1f0]::TR()->
[bffff1f0]::<-TR()
[bffff1fc]::SB()->
[bffff1fc]::<-SB()
[bffff1f0]::EX()->
[bffff1f0]::<-EX()
[081e0f14]::T()->
[081e0f14]::<-T()
[081e0ef8]::TR(x)->
[081e0ef8]::<-TR(x)
[081e0f04]::SB(x)->
[081e0f04]::<-SB(x)
[081e0ef8]::EX(x)->
[081e0ef8]::<-EX(x)
[bffff1f0]::~EX()->
[bffff1f0]::<-~EX()
[bffff1fc]::~SB()->
[bffff1fc]::<-~SB()
[bffff1f0]::~TR()->
[bffff1f0]::<-~TR()
[bffff20c]::~T()->
[bffff20c]::<-~T()
got the throw
[081e5b64]::T()->
[081e5b64]::<-T()
[081e5b48]::TR(x)->
[081e5b48]::<-TR(x)
[081e5b54]::SB(x)->
[081e5b54]::<-SB(x)
[081e5b48]::EX(x)->
[081e5b48]::<-EX(x)
[081e0ef8]::~EX()->
[081e0ef8]::<-~EX()
[081e0f04]::~SB()->
[081e0f04]::<-~SB()
[081e0ef8]::~TR()->
[081e0ef8]::<-~TR()
[081e0f14]::~T()->
[081e0f14]::<-~T()
got it
[081e5b54]::~EX()->
[081e5b54]::<-~EX()