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>From jupiter.zir.ethz.ch!conti Tue Jul 25 12:17:05 MET 1989 remote from ethz

Michael,

I've tried to compile a large program I had developed with ATT CC 1.2
with g++ 1.35 on a sun3-os4, and I have run into what I suppose to be
3 compiler bugs.

1. User-defined implicit conversions are not always performed as
described in Stroustrup, r.9.3. When compiled with g++ -v, the
following example produces the following error message:

------------- example------------
class C {

   unsigned i;
 public:
   operator unsigned(){return i;}
};

void main () {
   C    c;
   if (c) {
   }
}

------------------ error message -------------------------------
g++ version 1.35.1-
 /usr/local/lib/gcc-cpp -+ -v -undef -D__GNU__ -D__GNUG__ -D__cplusplus -Dmc68000 -Dsun -Dunix -D__mc68000__ -D__sun__ -D__unix__ -D__HAVE_68881__ -Dmc68020 test.C /tmp/cca03895.cpp
GNU CPP version 1.35
 /usr/local/lib/gcc-cc1plus /tmp/cca03895.cpp -quiet -dumpbase test.C -noreg -version -o /tmp/cca03895.s
GNU C++ version 1.35.1- (68k, MIT syntax) compiled by GNU C version 1.35.
In function void main ():
test.C:10: type conversion required for type `C'


2. Declaration of 2-dimensional arrays of class objects with a class
constructor cause a compiler crash.

------------------- example ------------------------
class C {

   int i;
 public:
   C () {}
};

void main () {
   C    c[3][4];
}

------------------ error message ------------------------
g++ version 1.35.1-
 /usr/local/lib/gcc-cpp -+ -v -undef -D__GNU__ -D__GNUG__ -D__cplusplus -Dmc68000 -Dsun -Dunix -D__mc68000__ -D__sun__ -D__unix__ -D__HAVE_68881__ -Dmc68020 test.C /tmp/cca03904.cpp
GNU CPP version 1.35
 /usr/local/lib/gcc-cc1plus /tmp/cca03904.cpp -quiet -dumpbase test.C -noreg -version -o /tmp/cca03904.s
GNU C++ version 1.35.1- (68k, MIT syntax) compiled by GNU C version 1.35.
In function void main ():
test.C:9: Segmentation violation
g++: Program cc1plus got fatal signal 11.

3. Formal arguments declared as constant arrays of class pointers
are not handled properly. In the following example, the array of
pointers to integers is accepted as actual parameter (as I expected it
to be), while the array of pointers to class objects is not. A
workaround for my code is to define the array of pointers via a
typedef.

--------------------- example -------------------------------
class C {
   int i;
};

void f (const C* cp[3]) {}
      
void g (const int*  ip[3]) {}

void main () {
   C*     cp[3];
   int*   ip[3];

   f (cp);
   g (ip);
}


---------------------- error message ------------------------
g++ version 1.35.1-
 /usr/local/lib/gcc-cpp -+ -v -undef -D__GNU__ -D__GNUG__ -D__cplusplus -Dmc68000 -Dsun -Dunix -D__mc68000__ -D__sun__ -D__unix__ -D__HAVE_68881__ -Dmc68020 test.C /tmp/cca03910.cpp
GNU CPP version 1.35
 /usr/local/lib/gcc-cc1plus /tmp/cca03910.cpp -quiet -dumpbase test.C -noreg -version -o /tmp/cca03910.s
GNU C++ version 1.35.1- (68k, MIT syntax) compiled by GNU C version 1.35.
In function void main ():
test.C:13: argument passing between incompatible pointer types

                              __paolo


---------------------
Paolo Conti
Integrated Systems Lab
Swiss federal Institute of Technology
ETH-Zentrum
8092 Zuerich (Switzerland)

conti@iis.ethz.ch
conti@iis.uucp
conti@czheth5a.bitnet