g++
>Submitter-Id: net
>Originator: Ove Kaaven <ovek@arcticnet.no>
>Organization: The Debian project
>Confidential: no
>Synopsis: g++
>Severity: serious
>Priority: low
>Category: c++
>Class: wrong-code
>Release: 3.0.1 (CVS 20010801) (Debian GNU/Linux)
>Environment:
System: Debian GNU/Linux (testing/unstable)
Architecture: sparc
host: sparc-linux
build: sparc-linux
target: sparc-linux
configured with: ../src/configure -v --enable-languages=c,c++,java,f77,proto,objc --prefix=/usr --infodir=/share/info --mandir=/share/man --enable-shared --with-gnu-as --with-gnu-ld --with-system-zlib --enable-long-long --enable-nls --without-included-gettext --disable-checking --enable-threads=posix --enable-java-gc=boehm --with-cpp-install-dir=bin --enable-objc-gc sparc-linux
>Description:
[ Reported to the Debian BTS as report #88694.
Please CC 88694-quiet@bugs.debian.org on replies.
Log of report can be found at http://bugs.debian.org/88694 ]
The compiler optimizes out the variable, which is OK without -g, but
with -g, the stabs debugging info explicitly references the
optimized-out variable, causing an undefined reference, and the
application (e.g. flightgear) will fail to link (seen on sparc-linux,
not i386-linux).
typedef double SCALAR;
typedef SCALAR VECTOR_3[3];
class LaRCsimIC {
public:
SCALAR xlo, xhi,xmin,xmax;
typedef SCALAR (LaRCsimIC::*fp)(SCALAR x);
fp sfunc;
bool solve( SCALAR *y,SCALAR x);
};
bool LaRCsimIC::solve( SCALAR *y,SCALAR x) {
float x1,x2,x3,f1,f2,f3,d,d0;
float eps=1E-5;
float const relax =0.9;
int i;
bool success=false;
d=1;
x1=xlo;x3=xhi;
f1=(this->*sfunc)(x1)-x;
f3=(this->*sfunc)(x3)-x;
d0=fabs(x3-x1);
//iterations
i=0;
while ((fabs(d) > eps) && (i < 100)) {
d=(x3-x1)/d0;
x2=x1-d*d0*f1/(f3-f1);
f2=(this->*sfunc)(x2)-x;
if(fabs(f2) <= 0.001) {
x1=x3=x2;
} else if(f1*f2 <= 0.0) {
x3=x2;
f3=f2;
f1=relax*f1;
} else if(f2*f3 <= 0) {
x1=x2;
f1=f2;
f3=relax*f3;
}
i++;
}//end while
if(i < 100) {
success=true;
*y=x2;
}
return success;
}
$ g++-3.0 -O2 -g -c bug.cc ; nm bug.o
0000000000000000 a *ABS*
U .LLC0
00000000000002c8 t Letext
0000000000000000 T _ZN9LaRCsimIC5solveEPdd
0000000000000000 ? __FRAME_BEGIN__
U __gxx_personality_v0
U fabs
$ g++-3.0 -O2 -c bug.cc ; nm bug.o
0000000000000000 a *ABS*
0000000000000000 T _ZN9LaRCsimIC5solveEPdd
0000000000000000 ? __FRAME_BEGIN__
U __gxx_personality_v0
U fabs
>How-To-Repeat:
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