This patch splits the TRY_CATCH macro into three, so that we go from
this:
~~~
volatile gdb_exception ex;
TRY_CATCH (ex, RETURN_MASK_ERROR)
{
}
if (ex.reason < 0)
{
}
~~~
to this:
~~~
TRY
{
}
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
~~~
Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.
This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.
TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:
TRY
{
}
// some code here.
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
Just like it isn't valid to do that with C++'s native try/catch.
By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.
The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved. After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch]. The result was folded into this patch so that GDB
still builds at each incremental step.
END_CATCH is necessary for two reasons:
First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:
#define CATCH(EXCEPTION, mask) \
for (struct gdb_exception EXCEPTION; \
exceptions_state_mc_catch (&EXCEPTION, MASK); \
EXCEPTION = exception_none)
would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.
Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow. That will
be done in END_CATCH.
After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.
IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.
gdb/ChangeLog.
2015-03-07 Pedro Alves <palves@redhat.com>
* common/common-exceptions.c (struct catcher) <exception>: No
longer a pointer to volatile exception. Now an exception value.
<mask>: Delete field.
(exceptions_state_mc_init): Remove all parameters. Adjust.
(exceptions_state_mc): No longer pop the catcher here.
(exceptions_state_mc_catch): New function.
(throw_exception): Adjust.
* common/common-exceptions.h (exceptions_state_mc_init): Remove
all parameters.
(exceptions_state_mc_catch): Declare.
(TRY_CATCH): Rename to ...
(TRY): ... this. Remove EXCEPTION and MASK parameters.
(CATCH, END_CATCH): New.
All callers adjusted.
gdb/gdbserver/ChangeLog:
2015-03-07 Pedro Alves <palves@redhat.com>
Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
instead.
In C, we can forward declare static structure instances. That doesn't
work in C++ though. C++ treats these as definitions. So then the
compiler complains about symbol redefinition, like:
src/gdb/elfread.c:1569:29: error: redefinition of ‘const sym_fns elf_sym_fns_lazy_psyms’
src/gdb/elfread.c:53:29: error: ‘const sym_fns elf_sym_fns_lazy_psyms’ previously declared here
The intent of static here is naturally to avoid making these objects
visible outside the compilation unit. The equivalent in C++ would be
to instead define the objects in the anonymous namespace. But given
that it's desirable to leave the codebase compiling as both C and C++
for a while, this just makes the objects extern.
(base_breakpoint_ops is already declared in breakpoint.h, so we can
just remove the forward declare from breakpoint.c)
gdb/ChangeLog:
2015-02-11 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
* breakpoint.c (base_breakpoint_ops): Delete.
* dwarf2loc.c (dwarf_expr_ctx_funcs): Make extern.
* elfread.c (elf_sym_fns_gdb_index, elf_sym_fns_lazy_psyms): Make extern.
* guile/guile.c (guile_extension_script_ops, guile_extension_ops): Make extern.
* ppcnbsd-tdep.c (ppcnbsd2_sigtramp): Make extern.
* python/py-arch.c (arch_object_type): Make extern.
* python/py-block.c (block_syms_iterator_object_type): Make extern.
* python/py-bpevent.c (breakpoint_event_object_type): Make extern.
* python/py-cmd.c (cmdpy_object_type): Make extern.
* python/py-continueevent.c (continue_event_object_type)
* python/py-event.h (GDBPY_NEW_EVENT_TYPE): Remove 'qual'
parameter. Update all callers.
* python/py-evtregistry.c (eventregistry_object_type): Make extern.
* python/py-exitedevent.c (exited_event_object_type): Make extern.
* python/py-finishbreakpoint.c (finish_breakpoint_object_type): Make extern.
* python/py-function.c (fnpy_object_type): Make extern.
* python/py-inferior.c (inferior_object_type, membuf_object_type): Make extern.
* python/py-infevents.c (call_pre_event_object_type)
(inferior_call_post_event_object_type).
(memory_changed_event_object_type): Make extern.
* python/py-infthread.c (thread_object_type): Make extern.
* python/py-lazy-string.c (lazy_string_object_type): Make extern.
* python/py-linetable.c (linetable_entry_object_type)
(linetable_object_type, ltpy_iterator_object_type): Make extern.
* python/py-newobjfileevent.c (new_objfile_event_object_type)
(clear_objfiles_event_object_type): Make extern.
* python/py-objfile.c (objfile_object_type): Make extern.
* python/py-param.c (parmpy_object_type): Make extern.
* python/py-progspace.c (pspace_object_type): Make extern.
* python/py-signalevent.c (signal_event_object_type): Make extern.
* python/py-symtab.c (symtab_object_type, sal_object_type): Make extern.
* python/py-type.c (type_object_type, field_object_type)
(type_iterator_object_type): Make extern.
* python/python.c (python_extension_script_ops)
(python_extension_ops): Make extern.
* stap-probe.c (stap_probe_ops): Make extern.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
* NEWS: Mention Python 3 support.
* varobj.c (value_get_print_value): Use
python_string_to_target_string.
* python/py-block.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
* python/py-breakpoint.c: Ditto.
* python/py-cmd.c: Ditto.
* python/py-event.c: Ditto.
* python/py-event.h: Ditto.
* python/py-evtregistry.c: Ditto.
* python/py-finishbreakpoint.c: Ditto.
* python/py-frame.c: Ditto.
* python/py-function.c: Ditto.
* python/py-infthread.c: Ditto.
* python/py-lazy-string.c: Ditto.
* python/py-progspace.c: Ditto.
* /python/py-symbol.c: Ditto.
* python/py-evts.c: (gdbpy_initialize_py_events): Add module
initialization for Python 3.
* python/py-inferior.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(infpy_read_memory): Return memoryview object if Python 3.
(infpy_write_memory): Use "s*" operand parsing code for Python 3.
(infpy_search_memory): Ditto.
(get_buffer): New function for Python 3.
* python/py-objfile.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(objfpy_dealloc): Use Py_TYPE to call tp_free.
* python/py-param.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(get_attr): Use PyUnicode_CompareWithASCIIString if Python 3.
(set_attr): Ditto.
* python/py-prettyprint.c (print_string_repr): use PyBytes methods
instead of PyString methods if Python 3.
(print_children): Skip push_dummy_python_frame call if Python 3.
* python/py-symtab.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(salpy_dealloc): Use Py_TYPE to call tp_free.
* python/py-type.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(field_dealloc): Use Py_TYPE to call tp_free.
(typy_dealloc): Ditto.
(type_object_as_number): Adjust struct initializations for
differences in layout for Python 2 vs. Python 3.
* python/py-utils.c (python_string_to_unicode): Omit non-Unicode
string case for Python 3.
(unicode_to_encoded_python_string): Shorten code (no functional
change).
(python_string_to_target_python_string): Comment that in Python 3
returned value is a Python "bytes" type.
(gdbpy_is_string): Omit non-Unicode string check in Python 3.
(gdb_py_object_from_longest): Omit non-long integer case in Python
3.
(gdb_py_object_from_ulongest): Ditto.
* python/py-value.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(valpy_dealloc): Use Py_TYPE to call tp_free.
(valpy_int): Omit function if Python 3.
(convert_value_from_python): Use "%S" format (Python object as a
string) if Python 3.
(value_object_as_number): Adjust struct initializations for
differences in layout for Python 2 vs. Python 3.
* python/python-config.py: Adjust syntax for Python 3
compatibility.
Include "sys.abiflags" string as part of python library name, if
that attribute exists (Python 3).
* python/python-internal.h (IS_PY3): Define if Python 3.
(Py_TPFLAGS_HAVE_ITER, Py_TPFLAGS_CHECKTYPES): Define with
placeholder value if Python 3.
(PyInt_Check, PyInt_FromLong, PyInt_AsLong, PyString_FromString,
PyString_Decode, PyString_FromFormat, PyString_Check): Define as
analogous Python 3 API function if Python 3.
(PyVarObject_HEAD_INIT): Define if not already defined.
(Py_TYPE): Ditto.
* python/python.c (eval_python_command): Omit Py_FlushLine call if
Python 3.
Check return values of all Python API calls for error.
Supply dummy "python" and "python-interactive" commands if Python
initialization failed.
(_initialize_python): Convert argc to wchar_t** if Python 3.
Add module initialization for Python 3.
(finish_python_initialization): Pass wchar_t * argument to
PySys_SetPath if Python 3.
* python/lib/gdb/__init__.py: Define "reload" if Python 3.
(_GdbFile): New class for common output file behavior.
(GdbOutFile): Subclass from _GdbFile.
(GdbOutputErrorFile): Ditto.
(auto_load_packages): Adjust syntax for Python 3 compatibility.
* python/lib/gdb/printing.py: Define basestr and int if Python 3.
* python/lib/gdb/prompt.py: Use sorted() function rather than
sort() method.
* python/lib/gdb/command/explore.py: Define raw_input if Python 3.
Adjust syntax for Python 3 compatibility.
* python/lib/gdb/command/pretty_printers.py: Use sorted() function
rather than sort() method.
Adjust syntax for Python 3 compatibility.
* python/lib/gdb/command/type_printers.py: Ditto.
* doc/gdb.texinfo (Inferior.read_memory): Mention that the return
value is a memoryview object if Python 3.
* python/py-breakpoint.c: Include python.h.
* python/py-continueevent.c (create_continue_event_object): Make
static.
* python/py-lazy-string.c (stpy_get_type): Make static.
* python/py-newobjfileevent.c (create_new_objfile_event_object):
Make static.
* python/py-utils.c (unicode_to_target_python_string): Make
static.
* python/py-value.c: Include python.h.
* python/py-auto-load.c: White space.
* python/py-block.c: White space.
* python/py-breakpoint.c: White space.
* python/py-cmd.c: White space.
* python/py-function.c: White space.
* python/py-lazy-string.c: White space.
* python/py-objfile.c: White space.
* python/py-param.c: White space.
* python/py-prettyprint.c: White space.
* python/py-progspace.c: White space.
* python/py-symtab.c: White space.
* python/python.c: White space.
* python/py-type.c: White space.
* python/py-utils.c: White space.
* python/py-value.c: White space.
PR python/11417
* python/py-lazy-string.c (stpy_convert_to_value): Check for
a NULL address.
(gdbpy_create_lazy_string_object): Allow strings with a NULL
address and a zero length.
2010-04-08 Phil Muldoon <pmuldoon@redhat.com>
* gdb.python/py-value: Add null string variable.
(test_lazy_string): Test zero length, NULL address lazy
strings.
