This is the mail archive of the
mailing list for the GDB project.
- From: Jason Merrill <jason at redhat dot com>
- To: gdb at sources dot redhat dot com
- Cc: Jason Merrill <jason at redhat dot com>
- Date: Thu, 10 Jan 2002 13:17:56 +0000
- Subject: gdb.c++ failures
I've been looking at the various C++ debugging failures on
i686-pc-linux-gnu using dwarf2. Here's my analysis:
anon-union.exp: The C++ compiler is emitting an extra lexical block, so
the breakpoint on the closing brace is treated as being outside the
scope of the variable. There are two issues here: The compiler output
is wrong, and the testcase is relying on corner-case behavior that only
works for the outermost block of a function. Of course, I don't know
how we could test for the compiler bug without doing this, so I suppose
we might as well leave the testcase alone.
classes.exp: dwarf2 doesn't provide mangled names for abstract
constructors, and there is a difference of opinion between the
demangler and c-typeprint.c as to whether the type should be written "A
const &" or "const A &". The demangler always puts the cv-qualifier
after the type it affects, whereas gdb puts it in front whenever that
would have the correct meaning. Either one could be changed to match
the other, or the testcase could be modified to accept either form.
Also, gdb is including artificial arguments in the printed
representation of the constructors for vB-vD. The dwarf2 output
indicates that they are artificial; gdb should not print them. There
doesn't seem to be a simple way to handle this in the current gdb data
cplusfuncs.exp: cp-demangle bug. The code to handle demangling
pointers-to-functions isn't complex enough.
local.exp: The test tries to examine InnerLocal outside of its scope,
which fails. Doing a ptype while InnerLocal is in scope works fine.
Meanwhile, ptype Local works outside of Local's scope; apparently being
inside an additional block makes a difference. This definitely seems
like a gdb issue.
method.exp: The 'print this' tests are failing because gdb is printing
the types as, say, (A * const), and the test just wants (A *). The
former is correct, since 'this' is readonly. Any objection to changing
the test (and others affected) to allow the const?
namespace.exp: gdb prints '\0', the testcase expects '\000'. An obvious
fix, which I will apply.
templates.exp: the artificial args problem breaks destructor
recognition. Also, when asked to set a breakpoint on a constructor, gdb
offers a menu of the different clones, which the testcase doesn't
like; it seems correct to me.
Also, the cv-qual placement issue breaks 'print Foo<volatile char *>::foo';
it needs to be 'print "Foo<char volatile*>::foo"' to match the demangler
output. I take it the aCC demangler makes different choices? I don't
see any way to get around the dependence of template naming on the
canonical format chosen by the demangler unless gdb learns to mangle
names itself; perhaps the syntax of the test should vary with the compiler.