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When debugging an Ada program, and inserting a watchpoint tracking
a local variable, the watchpoint doesn't get automatically deleted
upon leaving that variable's scope. This watchpoint then starts
creating problems later on, when trying to resume the program's
execution from a location outside of the watchpoint's scope:
(gdb) c
Continuing.
Breakpoint 2, foo_p708_025 () at foo_p708_025.adb:7
7 Do_Nothing (Val);
(gdb) n
No frame is currently executing in block pck.get_val.
Command aborted.
(gdb) c
Continuing.
No frame is currently executing in block pck.get_val.
Command aborted.
The expected output is the following:
- The program's execution after the first continue should stop
as soon as we reach the end of the watchpoint's scope, and
the debugger should be deleting it.
- Then we can continue until reaching breakpoint 2 above;
- After which we should be able to do next/continue as usual.
The reason the watchpoint is not automatically deleted at scope exit
is because the watchpoint is not marked as being scope-specific
(b->exp_valid_block is equal NULL), and this is because the
symbol lookup for our local variable failed to set the innermost_block
global variable during the lookup.
More precisely, if we look at watch_command_1, we do the following:
innermost_block = NULL;
[...]
exp = parse_exp_1 (&arg, 0, 0, 0);
[...]
exp_valid_block = innermost_block;
Currently, innermost_block stays NULL after the call to parse_exp_1.
Digging further, this innermost_block is typically set during symbol
lookup when the symbol is considered to have a frame-relative address.
For instance, in c-exp.y, we see some code like the following:
if (symbol_read_needs_frame (sym.symbol))
{
if (innermost_block == 0
|| contained_in (sym.block,
innermost_block))
innermost_block = sym.block;
}
We actually have the exact same mechanism in ada-exp.y, except
that it vhas accidently been turned off. See write_var_from_sym,
where we start with:
if (orig_left_context == NULL && symbol_read_needs_frame (sym))
{
if (innermost_block == 0
|| contained_in (block, innermost_block))
innermost_block = block;
}
In this case, orig_left_context is a parameter, and looking at
the point of call in write_var_or_type, we see:
if (nsyms == 1)
{
write_var_from_sym (par_state, block, syms[0].block,
syms[0].symbol);
In the call above, the paramater we are interested in is "block",
which is a parameter for write_var_or_type as well, except we
explicitly override its value at the beginning when found to be NULL:
if (block == NULL)
block = expression_context_block;
So the block we pass to write_var_from_sym is not NULL, and
we therefore don't set innermost_block, which leads to the watchpoint
no longer being marked as scope-specific.
The handling of orig_left_context in write_var_from_sym was there
to handle the case where a user writes an expression where the symbol
is qualified with a scope (Eg: "function::variable"). But it appears
that handling this is specifically here is no longer necessary,
so this patch simply removes that parameter and the associated check,
and then updates all the points of calls.
Interestingly, this also affects GDB/MI, and in particular varobjs,
because local variables are now properly reported as having a block,
which causes the associated varob to have a "thread-id" field.
This patch also adjusts a couple of Ada/gdb-mi tests.
gdb/ChangeLog:
* ada-exp.y (write_var_from_sym): Remove parameter
"orig_left_context". Update all callers.
gdb/testsuite/ChangeLog:
* gdb.ada/scoped_watch: New testcase.
* gdb.ada/watch_arg.exp: Adjust expected behavior to the behavior
which is actually correct.
* gdb.ada/mi_interface.exp: Add missing thread-id in expected varobj.
* gdb.ada/mi_var_array.exp: Add missing thread-id in expected varobj.
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| bfd | ||
| binutils | ||
| config | ||
| cpu | ||
| elfcpp | ||
| etc | ||
| gas | ||
| gdb | ||
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| include | ||
| intl | ||
| ld | ||
| libdecnumber | ||
| libiberty | ||
| opcodes | ||
| readline | ||
| sim | ||
| texinfo | ||
| zlib | ||
| .cvsignore | ||
| .gitattributes | ||
| .gitignore | ||
| ChangeLog | ||
| compile | ||
| config-ml.in | ||
| config.guess | ||
| config.rpath | ||
| config.sub | ||
| configure | ||
| configure.ac | ||
| COPYING | ||
| COPYING3 | ||
| COPYING3.LIB | ||
| COPYING.LIB | ||
| COPYING.LIBGLOSS | ||
| COPYING.NEWLIB | ||
| depcomp | ||
| djunpack.bat | ||
| install-sh | ||
| libtool.m4 | ||
| lt~obsolete.m4 | ||
| ltgcc.m4 | ||
| ltmain.sh | ||
| ltoptions.m4 | ||
| ltsugar.m4 | ||
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| MAINTAINERS | ||
| Makefile.def | ||
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| missing | ||
| mkdep | ||
| mkinstalldirs | ||
| move-if-change | ||
| README | ||
| README-maintainer-mode | ||
| setup.com | ||
| src-release.sh | ||
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| ylwrap | ||
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.