According to the spec, you can't assign the value of a less-restrictive
function pointer to a more-restrictive function pointer.
Relevant C++ Spec section: 15.4 -3- (except.spec)
==============================================================
Code below taken directly from the C++ spec above.
==============================================================
class A { /* ... */ };
void (*pf1)(); // no exception specification
void (*pf2)() throw(A);
void f()
{
pf1 = pf2; // OK: pf1 is less restrictive
pf2 = pf1; // error: pf2 is more restrictive
}
==============================================================
this compiles OK - it shouldn't.
the line marked
// error:
does not produce an error.
==============================================================
I ran through g++ under kdbg on a 1-line file:
void (*fp)() throw(int);
I'm not sure if I read it right but it seems that gcc just ignores function
pointer exception specifications altogether.
in gcc/cp/decl.c, in the behemoth that is grokdeclarator() which builds the
declarator.
there's this "tree" called "raises" that gets passed the exception spec, but
it's only used to check for errors, it's not embedded into the newly built
declarator.
gcc/cp/decl.c :: grokdeclarator() ::
=======================================
~8100: raises = declarator->u.function.exception_specification;
raises gets passed the spec.
~9172: decl = grokvardecl(.....);
..... (nothing important).
~9225: return decl;
grokvardecl builds the decl that's returned, but it's not passed "raises".
=======================================
"tree"'s are still confusing me so I'm not sure if it's possible to embed this
into the decl without breaking anything, but that'd be where I'd start (after I
was sure it wasn't already in there).
when -fdumping-tree-original, there's no exception spec for the function ptr,
but I guess it could've been stripped.
(checked buglist for "function pointer exception specification", didn't see any
dupes)
--
Summary: function pointer exception specification not checked
during assignment
Product: gcc
Version: 4.2.4
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: yacwroy at gmail dot com
GCC build triplet: x86_64-linux-gnu
GCC host triplet: x86_64-linux-gnu
GCC target triplet: x86_64-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38069
