PROBLEMS   [plain text]

			Known problems in GDB 6.3

		See also:

*** Build problems

build/1411: build fails on hpux 10.20 and hpux 11.00 with CMA threads

GDB does not build on HP/UX 10.20 or HP/UX 11.00 if the CMA
thread package is installed.  The compile error is:

  ../../gdb/hpux-thread.c:222: variable-size type declared outside of any function

This happens only if the CMA thread package is installed.

As a workaround, you can disable support for CMA threads
by editing the file gdb/configure.  Find the line:

  if test -f /usr/include/dce/cma_config.h ; then

And replace it with:

  if false ; then

*** Misc

gdb/1560: Control-C does not always interrupt GDB.

When GDB is busy processing a command which takes a long time to
complete, hitting Control-C does not have the expected effect.
The command execution is not aborted, and the "QUIT" message confirming
the abortion is displayed only after the command has been completed.

*** C++ support

gdb/931: GDB could be more generous when reading types C++ templates on input

When the user types a template, GDB frequently requires the type to be
typed in a certain way (e.g. "const char*" as opposed to "const char *"
or "char const *" or "char const*").

gdb/1512: no canonical way to output names of C++ types

We currently don't have any canonical way to output names of C++ types.
E.g. "const char *" versus "char const *"; more subtleties arise when
dealing with templates.

gdb/1516: [regression] local classes, gcc 2.95.3, dwarf-2

With gcc 2.95.3 and the dwarf-2 debugging format, classes which are
defined locally to a function include the demangled name of the function
as part of their name.  For example, if a function "foobar" contains a
local class definition "Local", gdb will say that the name of the class
type is "foobar__Fi.0:Local".

This applies only to classes where the class type is defined inside a
function, not to variables defined with types that are defined somewhere
outside any function (which most types are).

gdb/1588: names of c++ nested types in casts must be enclosed in quotes

You must type
  (gdb) print ('Foo::Bar') x
  (gdb) print ('Foo::Bar' *) y
instead of
  (gdb) print (Foo::Bar) x
  (gdb) print (Foo::Bar *) y

gdb/1091: Constructor breakpoints ignored
gdb/1193: g++ 3.3 creates multiple constructors: gdb 5.3 can't set breakpoints

When gcc 3.x compiles a C++ constructor or C++ destructor, it generates
2 or 3 different versions of the object code.  These versions have
unique mangled names (they have to, in order for linking to work), but
they have identical source code names, which leads to a great deal of
confusion.  Specifically, if you set a breakpoint in a constructor or a
destructor, gdb will put a breakpoint in one of the versions, but your
program may execute the other version.  This makes it impossible to set
breakpoints reliably in constructors or destructors.

gcc 3.x generates these multiple object code functions in order to
implement virtual base classes.  gcc 2.x generated just one object code
function with a hidden parameter, but gcc 3.x conforms to a multi-vendor
ABI for C++ which requires multiple object code functions.

*** Threads

threads/1650: manythreads.exp

On GNU/Linux systems that use the old LinuxThreads thread library, a
program rapidly creating and deleting threads can confuse GDB leading
to an internal error.

This problem does not occur on newer systems that use the NPTL
library, and did not occur with GDB 6.1.