Bug 20976

Sorry, cannot understand how to attach the different files you ask for or what
the host/target/build triplets are supposed to be (no mention of these in the
how-tos).

The bug: I was under the impression, that if an exception occurs the destructors
of the local objects should be called at some point, even if we don't catch the
exception anywhere.
The behaviour however of g++ (tried it with 3.4.4 and 3.3.5) is different.
It only executes the destructors if the exception is caught somewhere (doesn't
matter if it's rethrown or not).

Platform / Compiler info & test program follow.

Take care & thanks for the great work! :-)
Christos

$ uname -a
Linux adia 2.6.8.1 #1 SMP Tue Oct 5 03:46:19 CEST 2004 i686 GNU/Linux
$
$ g++-3.4 -v -save-temps exceptions.cc -o exceptions
Reading specs from /usr/lib/gcc/i486-linux/3.4.4/specs
Configured with: ../src/configure -v
--enable-languages=c,c++,java,f77,pascal,objc,ada,treelang --prefix=/usr
--libexecdir=/usr/lib --with-gxx-include-dir=/usr/include/c++/3.4
--enable-shared --with-system-zlib --enable-nls --without-included-gettext
--program-suffix=-3.4 --enable-__cxa_atexit --enable-libstdcxx-allocator=mt
--enable-clocale=gnu --enable-libstdcxx-debug --enable-java-gc=boehm
--enable-java-awt=gtk --disable-werror i486-linux
Thread model: posix
gcc version 3.4.4 20041218 (prerelease) (Debian 3.4.3-6)
 /usr/lib/gcc/i486-linux/3.4.4/cc1plus -E -quiet -v -D_GNU_SOURCE exceptions.cc
-mtune=i486 -o exceptions.ii
ignoring nonexistent directory
"/usr/lib/gcc/i486-linux/3.4.4/../../../../i486-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/3.4
 /usr/include/c++/3.4/i486-linux
 /usr/include/c++/3.4/backward
 /usr/local/include
 /usr/lib/gcc/i486-linux/3.4.4/include
 /usr/include
End of search list.
 /usr/lib/gcc/i486-linux/3.4.4/cc1plus -fpreprocessed exceptions.ii -quiet
-dumpbase exceptions.cc -mtune=i486 -auxbase exceptions -version -o exceptions.s
GNU C++ version 3.4.4 20041218 (prerelease) (Debian 3.4.3-6) (i486-linux)
        compiled by GNU C version 3.4.4 20041218 (prerelease) (Debian 3.4.3-6).
GGC heuristics: --param ggc-min-expand=64 --param ggc-min-heapsize=64194
 as -V -Qy --32 -o exceptions.o exceptions.s
GNU assembler version 2.15 (i386-linux) using BFD version 2.15
 /usr/lib/gcc/i486-linux/3.4.4/collect2 --eh-frame-hdr -m elf_i386
-dynamic-linker /lib/ld-linux.so.2 -o exceptions
/usr/lib/gcc/i486-linux/3.4.4/../../../../lib/crt1.o
/usr/lib/gcc/i486-linux/3.4.4/../../../../lib/crti.o
/usr/lib/gcc/i486-linux/3.4.4/crtbegin.o -L/usr/lib/gcc/i486-linux/3.4.4
-L/usr/lib/gcc/i486-linux/3.4.4 -L/usr/lib/gcc/i486-linux/3.4.4/../../../../lib
-L/usr/lib/gcc/i486-linux/3.4.4/../../.. -L/lib/../lib -L/usr/lib/../lib
exceptions.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc
/usr/lib/gcc/i486-linux/3.4.4/crtend.o
/usr/lib/gcc/i486-linux/3.4.4/../../../../lib/crtn.o
$ ./exceptions
  Unknown exception
terminate called after throwing an instance of 'B'
Aborted
$


Here's the program (email me for the .ii.bz file - couldn't spot any "attach"
button):

#include <iostream>
using namespace std;
class A {
  public:
   static int last_id;
   int id;
   A();
   virtual ~A();
};
int A::last_id = 0;

A::A() : id(++last_id) {}
A::~A() { cerr << '\t' << id << '\n'; }

// class B : public A {}; // B is a subclass of A
class B {}; // B now has no relationship to A

void f() {
   A a1;
   A a2;

   try {
     throw B();
   } catch (A a) {
     cerr << "  Caught an A : " << a.id << '\n';
   } catch (...) {
     cerr << "  Unknown exception\n";
     throw; // rethrow it
   }
}

int main() {
#ifdef OK
   try {
     f();
   } catch (...) {
     throw;
   }
#else
   f();
   // BUG: Shouldn't it have executed the destructors of a1,a2 (f's local vars)
before exiting???
#endif
   return 0;
}