Currently inferior memory is allocated by inferior mmap() but it is never
deallocated; despite the injected objfile incl. its symbols is freed. This was
intentional so that one can do for example:
inferior:
char *str = "foo";
GDB:
(gdb) compile code str = "bar";
I believe later patches will be needed to introduce full control over keeping
vs. discarding the injected module as being discussed in:
compile: objfiles lifetime UI
https://sourceware.org/ml/gdb/2015-04/msg00051.html
Message-ID: <20150429135735.GA16974@host1.jankratochvil.net>
https://sourceware.org/ml/gdb/2015-05/msg00007.html
As decided by Phil it is better not to leak inferior pages as users can
workaround the issue above for example by:
(gdb) compile code str = strdup ("bar");
I have checked that in fact gdb/doc/ (written by Phil) already expects the
injected code will be unmapped so that does not need to be changed:
compile code int ff = 5; p = &ff;
In this example, @code{p} would point to @code{ff} when the
@code{compile} command is executing the source code provided to it.
However, as variables in the (example) program persist with their
assigned values, the variable @code{p} would point to an invalid
location when the command exists.
gdb/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* arch-utils.c (default_infcall_munmap): New.
* arch-utils.h (default_infcall_munmap): New declaration.
* compile/compile-object-load.c (struct munmap_list, munmap_list_add)
(munmap_list_free, munmap_listp_free_cleanup): New.
(struct setup_sections_data): Add field munmap_list_headp.
(setup_sections): Call munmap_list_add.
(compile_object_load): New variable munmap_list_head, initialize
setup_sections_data.munmap_list_headp, return munmap_list_head.
* compile/compile-object-load.h (struct munmap_list): New declaration.
(struct compile_module): Add field munmap_list_head.
(munmap_list_free): New declaration.
* compile/compile-object-run.c (struct do_module_cleanup): Add field
munmap_list_head.
(do_module_cleanup): Call munmap_list_free.
(compile_object_run): Pass munmap_list_head to do_module_cleanup.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbarch.sh (infcall_munmap): New.
* linux-tdep.c (linux_infcall_munmap): New.
(linux_init_abi): Install it.
gdb/testsuite/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile.exp (keep jit in memory): Rename to ...
(do not keep jit in memory): ... this.
(expect 5): Change it to ...
(expect no 5): ... this.
Please send debug output to gdb_stdlog.
OK but gdb/compile/ is using now only gdb_stdout; the error above is due to
a copy-paste. So I will send a follow-up patch to change all the other
gdb/compile/ gdb_stdout strings to gdb_stdlog.
gdb/ChangeLog
2015-05-19 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-c-symbols.c (convert_symbol_sym, gcc_convert_symbol)
(gcc_symbol_address): Change gdb_stdout to gdb_stdlog.
* compile/compile-object-load.c (setup_sections, compile_object_load):
Likewise.
* compile/compile.c (compile_to_object): Likewise.
It is planned the existing GDB command 'print' will be able to evaluate its
expressions using the compiler. There will be some option to choose between
the existing GDB evaluation and the compiler evaluation. But as an
intermediate step this patch provides the expression printing feature as a new
command.
I can imagine it could be also called 'maintenance compile print' as in the
future one should be able to use its functionality by the normal 'print'
command.
There was a discussion with Eli about the command name:
https://sourceware.org/ml/gdb-patches/2015-03/msg00880.html
As there were no other comments yet I haven't renamed it yet, before there is
some confirmation about settlement on the final name.
Support for the GDB '@' operator to create arrays has been submitted for GCC:
[gcc patch] libcc1: '@' GDB array operator
https://gcc.gnu.org/ml/gcc-patches/2015-03/msg01451.html
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
Phil Muldoon <pmuldoon@redhat.com>
* NEWS (Changes since GDB 7.9): Add compile print.
* compile/compile-c-support.c (add_code_header, add_code_footer)
(c_compute_program): Add COMPILE_I_PRINT_ADDRESS_SCOPE and
COMPILE_I_PRINT_VALUE_SCOPE.
* compile/compile-internal.h (COMPILE_I_PRINT_OUT_ARG_TYPE)
(COMPILE_I_PRINT_OUT_ARG, COMPILE_I_EXPR_VAL, COMPILE_I_EXPR_PTR_TYPE):
New.
* compile/compile-object-load.c: Include block.h.
(get_out_value_type): New function.
(compile_object_load): Handle COMPILE_I_PRINT_ADDRESS_SCOPE and
COMPILE_I_PRINT_VALUE_SCOPE. Set compile_module's OUT_VALUE_ADDR and
OUT_VALUE_TYPE.
* compile/compile-object-load.h (struct compile_module): Add fields
out_value_addr and out_value_type.
* compile/compile-object-run.c: Include valprint.h and compile.h.
(struct do_module_cleanup): Add fields out_value_addr and
out_value_type.
(do_module_cleanup): Handle COMPILE_I_PRINT_ADDRESS_SCOPE and
COMPILE_I_PRINT_VALUE_SCOPE.
(compile_object_run): Propagate out_value_addr and out_value_type.
Pass OUT_VALUE_ADDR.
* compile/compile.c: Include valprint.h.
(compile_print_value, compile_print_command): New functions.
(eval_compile_command): Handle failed COMPILE_I_PRINT_ADDRESS_SCOPE.
(_initialize_compile): Update compile code help text. Install
compile_print_command.
* compile/compile.h (compile_print_value): New prototype.
* defs.h (enum compile_i_scope_types): Add
COMPILE_I_PRINT_ADDRESS_SCOPE and COMPILE_I_PRINT_VALUE_SCOPE.
gdb/doc/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.texinfo (Compiling and Injecting Code): Add compile print.
gdb/testsuite/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile-print.c: New file.
* gdb.compile/compile-print.exp: New file.
Currently the code fetches _gdb_expr address/types at multiple places, guessing
its parameters at multiple places etc.
Fetch it once, verify it has expected type and then rely on it.
While the patch tries to clean up the code it is still horrible due to the
missing C++ sub-classing.
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-object-load.c (get_regs_type): Add parameter func_sym.
Rely on its parameter count.
(compile_object_load): Replace lookup_minimal_symbol_text by
lookup_global_symbol_from_objfile. Verify FUNC_SYM. Set it in the
return value.
* compile/compile-object-load.h (struct compile_module): Replace
func_addr by func_sym.
* compile/compile-object-run.c: Include block.h.
(compile_object_run): Reset module variable after it is freed. Use
FUNC_SYM instead of FUNC_ADDR. Rely on it.
For a reason unknown to me GDB was using -w instead of -Wall for 'compile code'.
The problem is later patch for 'compile printf' really needs some warnings to
be able to catch for example missing format string parameters:
(gdb) compile printf "%d\n"
GCC does not seem to be able to cancel -w (there is nothing like -no-w).
Besides that I think even 'compile code' can benefit from -Wall.
That #ifndef change in print_one_macro() is needed otherwise we get
macro-redefinition warnings for the GCC built-in macros (as -w is no
longer in effect). For example, without the #ifndef/#endif one gets:
compile -r -- void _gdb_expr(){int i = 5;}^M
/tmp/gdbobj-xpU1yB/out4.c:4:0: warning: "__FILE__" redefined [-Wbuiltin-macro-redefined]^M
/tmp/gdbobj-xpU1yB/out4.c:5:0: warning: "__LINE__" redefined^M
...
It makes more sense to pick the inferior's version of the macros, hence
#ifndef instead of #undef.
That new testsuite XFAIL is there as if one changes the struct definition to be
compliant with cv-qualifiers (to prevent the warnings):
struct struct_type {
- struct struct_type *selffield;
+ volatile struct struct_type *selffield;
only then GCC/GDB will hit the crash, described in that GDB PR 18202.
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-c-support.c (print_one_macro): Use #ifndef.
(generate_register_struct): Use __gdb_uintptr for TYPE_CODE_PTR.
(c_compute_program): Call generate_register_struct after typedefs.
* compile/compile-loc2c.c (push, pushf_register_address)
(pushf_register): Cast to GCC_UINTPTR.
(do_compile_dwarf_expr_to_c): Use unused attribute. Add space after
type. Use GCC_UINTPTR instead of void *. Remove excessive cast.
(compile_dwarf_expr_to_c): Use GCC_UINTPTR instead of void *.
* compile/compile.c (_initialize_compile): Enable warnings for
COMPILE_ARGS.
gdb/testsuite/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile-ops.exp: Cast param to void.
* gdb.compile/compile.exp: Complete type for _gdb_expr.
(compile code struct_object.selffield = &struct_object): Add xfail.
Provide a way to access current 'scope' during the do_module_cleanup stage and
associate more data with it.
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* cli/cli-script.c (execute_control_command): Update
eval_compile_command caller.
* compile/compile-object-load.c (compile_object_load): Add parameters
scope and scope_data. Set them.
* compile/compile-object-load.h (struct compile_module): Add fields
scope and scope_data.
(compile_object_load): Add parameters scope and scope_data.
* compile/compile-object-run.c (struct do_module_cleanup): Add fields
scope and scope_data.
(compile_object_run): Propagate the fields scope and scope_data.
* compile/compile.c (compile_file_command, compile_code_command):
Update eval_compile_command callers.
(eval_compile_command): Add parameter scope_data. Pass it plus scope.
* compile/compile.h (eval_compile_command): Add parameter scope_data.
* defs.h (struct command_line): Add field scope_data.
There was now a leak-like bug that if dummy_frame "disappeared" by
remove_dummy_frame then its destructor was not called. For example in the case
of 'compile code' dummy frames the injected objfile would never get freed after
some inferior longjmp out of the injected code.
gdb/ChangeLog
2015-05-13 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-object-run.c (do_module_cleanup): Add parameter
registers_valid.
(compile_object_run): Update do_module_cleanup caller.
* dummy-frame.c: Include infcall.h.
(struct dummy_frame): Update dtor comment.
(remove_dummy_frame): Call dtor.
(pop_dummy_frame): Update dtor caller.
* dummy-frame.h (dummy_frame_dtor_ftype): Add parameter
registers_valid.
Calling memcpy() could fail as memcpy() from libc is GNU-IFUNC.
gdb/ChangeLog
2015-05-06 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-object-load.c (compile_object_load): Support
mst_text_gnu_ifunc.
gdb/ChangeLog
2015-05-06 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile.c (compile_to_object): Make the cmd_string parameter
const. Use new variables for the const compatibility.
(eval_compile_command): Make the cmd_string parameter const.
* compile/compile.h (eval_compile_command): Make the cmd_string
parameter const.
This allows triplets where the vendor is not set.
gdb/ChangeLog:
2015-03-31 Matthias Klose <doko@ubuntu.com>
* compile/compile.c (compile_to_object): Allow triplets with or
without vendor set.
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.
This normalizes some exception catch blocks that check for ex.reason
to look like this:
~~~
volatile gdb_exception ex;
TRY_CATCH (ex, RETURN_MASK_ALL)
{
...
}
if (ex.reason < 0)
{
...
}
~~~
This is a preparation step for running a script that converts all
TRY_CATCH uses to look like this instead:
~~~
TRY
{
...
}
CATCH (ex, RETURN_MASK_ALL)
{
...
}
END_CATCH
~~~
The motivation for that change is being able to reimplent TRY/CATCH in
terms of C++ try/catch.
This commit makes it so that:
- no condition other than ex.reason < 0 is checked in the if
predicate
- there's no "else" block to check whether no exception was caught
- there's no code between the TRY_CATCH (TRY) block and the
'if (ex.reason < 0)' block (CATCH).
- the exception object is no longer referred to outside the if/catch
block. Note the local volatile exception objects that are
currently defined inside functions that use TRY_CATCH will
disappear. In cases it's more convenient to still refer to the
exception outside the catch block, a new non-volatile local is
added and copy to that object is made within the catch block.
The following patches should make this all clearer.
gdb/ChangeLog:
2015-03-07 Pedro Alves <palves@redhat.com>
* amd64-tdep.c (amd64_frame_cache, amd64_sigtramp_frame_cache)
(amd64_epilogue_frame_cache): Normal exception handling code.
* break-catch-throw.c (check_status_exception_catchpoint)
(re_set_exception_catchpoint): Ditto.
* cli/cli-interp.c (safe_execute_command):
* cli/cli-script.c (script_from_file): Ditto.
* compile/compile-c-symbols.c (generate_c_for_for_one_variable):
Ditto.
* compile/compile-object-run.c (compile_object_run): Ditto.
* cp-abi.c (baseclass_offset): Ditto.
* cp-valprint.c (cp_print_value): Ditto.
* exceptions.c (catch_exceptions_with_msg):
* frame-unwind.c (frame_unwind_try_unwinder): Ditto.
* frame.c (get_frame_address_in_block_if_available): Ditto.
* i386-tdep.c (i386_frame_cache, i386_epilogue_frame_cache)
(i386_sigtramp_frame_cache): Ditto.
* infcmd.c (post_create_inferior): Ditto.
* linespec.c (parse_linespec, find_linespec_symbols):
* p-valprint.c (pascal_object_print_value): Ditto.
* parse.c (parse_expression_for_completion): Ditto.
* python/py-finishbreakpoint.c (bpfinishpy_init): Ditto.
* remote.c (remote_get_noisy_reply): Ditto.
* s390-linux-tdep.c (s390_frame_unwind_cache): Ditto.
* solib-svr4.c (solib_svr4_r_map): Ditto.
This commit introduces a new inline common function "startswith"
which takes two string arguments and returns nonzero if the first
string starts with the second. It also updates the 295 places
where this logic was written out longhand to use the new function.
gdb/ChangeLog:
* common/common-utils.h (startswith): New inline function.
All places where this logic was used updated to use the above.
Fixes building gdb on x86_64-apple-darwin14 with clang, which produces
a number of warnings from -Wformat-nonliteral.
Ref: https://sourceware.org/ml/gdb/2015-02/msg00047.html
gdb/ChangeLog:
2015-02-26 Pedro Alves <palves@redhat.com>
* auto-load.h (file_is_auto_load_safe): Add ATTRIBUTE_PRINTF.
* complaints.c (vcomplaint): Pass argument FMT directly to
printf-like functions instead of complaint->fmt.
* ctf.c (ctf_save_write_metadata): Add ATTRIBUTE_PRINTF.
* darwin-nat.c (inferior_debug): Add ATTRIBUTE_PRINTF.
* compile/compile-loc2c.c (pushf, unary, binary): Add
ATTRIBUTE_PRINTF.
(do_compile_dwarf_expr_to_c): Pass string literal as format string
to pushf.
(BINARY): Pass string literal as format string to 'binary'.
* compile/compile-object-load.c (link_callbacks_einfo): Add
ATTRIBUTE_PRINTF.
* guile/guile-internal.h (gdbscm_printf): Add ATTRIBUTE_PRINTF.
One could not call IFUNCs (=indirect functions) from the compiled injected
code. Either it errored with:
gdb command line:1:1: error: function return type cannot be function
or it just called the IFUNC dispatcher in normal way, returning real function
implementation address instead of the function return value (and thus no
function was called).
gdb/ChangeLog
2015-02-26 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-c-symbols.c (convert_one_symbol, convert_symbol_bmsym)
(gcc_symbol_address): Call gnu_ifunc_resolve_addr.
gdb/testsuite/ChangeLog
2015-02-26 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile-ifunc.c: New file.
* gdb.compile/compile-ifunc.exp: New file.
With global system gcc-5.0 if one also installs ccache (needing a different
patch
https://bugzilla.samba.org/show_bug.cgi?id=11060
for -fplugin=libcc1plugin) it breaks as GDB will read from inferior
DW_AT_producer containing -fpreprocessed (due to ccache used to compile the
inferior).
<c> DW_AT_producer : (indirect string, offset: 0x52): GNU C11 5.0.0 20150114 (Red Hat 5.0.0-0.1) -fpreprocessed -mtune=generic -
march=x86-64 -g
It is wrong that gcc puts -fpreprocessed into DW_AT_producer - fixed it in
trunk GCCs:
https://gcc.gnu.org/ml/gcc-patches/2015-01/msg01495.html
But even with that fix there are already built inferiors out there which GDB
could be compatible (for the 'compile' mode) with.
gdb/ChangeLog
2015-02-03 Jan Kratochvil <jan.kratochvil@redhat.com>
Filter out inferior gcc option -fpreprocessed.
* compile/compile.c (filter_args): New function.
(get_args): Use it.
TBH while I always comment reasons for each of the compilation options in
reality I tried them all and chose that combination that needs the most simple
compile/compile-object-load.c (ld.so emulation) implementation.
gdb/ChangeLog
2015-01-22 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile.c (_initialize_compile): Use -fPIE for compile_args.
gdb/testsuite/ChangeLog
2015-01-22 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile.exp (pointer to jit function): New test.
On Sun, 14 Dec 2014 07:00:28 +0100, Yao Qi wrote:
The build on mingw host is broken because mingw has no mkdtemp.
../../../git/gdb/compile/compile.c: In function 'get_compile_file_tempdir':
../../../git/gdb/compile/compile.c:194:3: error: implicit declaration of function 'mkdtemp' [-Werror=implicit-function-declaration]
tempdir_name = mkdtemp (tname);
^
../../../git/gdb/compile/compile.c:194:16: error: assignment makes pointer from integer without a cast [-Werror]
tempdir_name = mkdtemp (tname);
^
cc1: all warnings being treated as errors
In the end I have managed to test it by Wine myself:
$ wine build_win32/gdb/gdb.exe -q build_win32/gdb/gdb.exe -ex start -ex 'compile code 1' -ex 'set confirm no' -ex quit
[...]
Temporary breakpoint 1, main (argc=1, argv=0x241418) at ../../gdb/gdb.c:29
29 args.argc = argc;
Could not load libcc1.so: Module not found.
Even if it managed to load libcc1.so (it needs host-dependent name libcc1.dll)
then it would soon end up at least on:
default_infcall_mmap:
error (_("This target does not support inferior memory allocation by mmap."));
As currently there is only:
linux-tdep.c:
set_gdbarch_infcall_mmap (gdbarch, linux_infcall_mmap);
While one could debug Linux targets from MS-Windows host I find it somehow
overcomplicated now when we are trying to get it running at least on native
Linux x86*.
The 'compile' project needs a larger port effort to run on MS-Windows.
gdb/ChangeLog
2014-12-17 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix MinGW compilation.
* compile/compile.c (get_compile_file_tempdir): Call error if
!HAVE_MKDTEMP.
* config.in: Regenerate.
* configure: Regenerate.
* configure.ac (AC_CHECK_FUNCS): Add mkdtemp.
gdb/testsuite/ChangeLog
2014-12-17 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix MinGW compilation.
* gdb.compile/compile-ops.exp: Update untested message if
!skip_compile_feature_tests.
* gdb.compile/compile-setjmp.exp: Likewise.
* gdb.compile/compile-tls.exp: Likewise.
* gdb.compile/compile.exp: Likewise.
* lib/gdb.exp (skip_compile_feature_tests): Check also "Command not
supported on this host".
gdb/ChangeLog:
* compile/compile-object-load.c (link_callbacks_multiple_definition)
(link_callbacks_warning, link_callbacks_einfo): Remove trailing
newline at end of warning message.
Tested on x86_64-linux.
This final patch adds the new "compile" command and subcommands, and
all the machinery needed to make it work.
A shared library supplied by gcc is used for all communications with
gcc. Types and most aspects of symbols are provided directly by gdb
to the compiler using this library.
gdb provides some information about the user's code using plain text.
Macros are emitted this way, and DWARF location expressions (and
bounds for VLA) are compiled to C code.
This hybrid approach was taken because, on the one hand, it is better
to provide global declarations and such on demand; but on the other
hand, for local variables, translating DWARF location expressions to C
was much simpler than exporting a full compiler API to gdb -- the same
result, only easier to implement, understand, and debug.
In the ordinary mode, the user's expression is wrapped in a dummy
function. After compilation, gdb inserts the resulting object code
into the inferior, then calls this function.
Access to local variables is provided by noting which registers are
used by location expressions, and passing a structure of register
values into the function. Writes to registers are supported by
copying out these values after the function returns.
This approach was taken so that we could eventually implement other
more interesting features based on this same infrastructure; for
example, we're planning to investigate inferior-side breakpoint
conditions.
gdb/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
Tom Tromey <tromey@redhat.com>
* NEWS: Update.
* symtab.h (struct symbol_computed_ops) <generate_c_location>: New
field.
* p-lang.c (pascal_language_defn): Update.
* opencl-lang.c (opencl_language_defn): Update.
* objc-lang.c (objc_language_defn): Update.
* m2-lang.c (m2_language_defn): Update.
* language.h (struct language_defn) <la_get_compile_instance,
la_compute_program>: New fields.
* language.c (unknown_language_defn, auto_language_defn)
(local_language_defn): Update.
* jv-lang.c (java_language_defn): Update.
* go-lang.c (go_language_defn): Update.
* f-lang.c (f_language_defn): Update.
* dwarf2loc.h (dwarf2_compile_property_to_c): Declare.
* dwarf2loc.c (dwarf2_compile_property_to_c)
(locexpr_generate_c_location, loclist_generate_c_location): New
functions.
(dwarf2_locexpr_funcs, dwarf2_loclist_funcs): Update.
* defs.h (enum compile_i_scope_types): New.
(enum command_control_type) <compile_control>: New constant.
(struct command_line) <control_u>: New field.
* d-lang.c (d_language_defn): Update.
* compile/compile.c: New file.
* compile/compile-c-support.c: New file.
* compile/compile-c-symbols.c: New file.
* compile/compile-c-types.c: New file.
* compile/compile.h: New file.
* compile/compile-internal.h: New file.
* compile/compile-loc2c.c: New file.
* compile/compile-object-load.c: New file.
* compile/compile-object-load.h: New file.
* compile/compile-object-run.c: New file.
* compile/compile-object-run.h: New file.
* cli/cli-script.c (multi_line_command_p, print_command_lines)
(execute_control_command, process_next_line)
(recurse_read_control_structure): Handle compile_control.
* c-lang.h (c_get_compile_context, c_compute_program): Declare.
* c-lang.c (c_language_defn, cplus_language_defn)
(asm_language_defn, minimal_language_defn): Update.
* ada-lang.c (ada_language_defn): Update.
* Makefile.in (SUBDIR_GCC_COMPILE_OBS, SUBDIR_GCC_COMPILE_SRCS):
New variables.
(SFILES): Add SUBDIR_GCC_COMPILE_SRCS.
(HFILES_NO_SRCDIR): Add compile.h.
(COMMON_OBS): Add SUBDIR_GCC_COMPILE_OBS.
(INIT_FILES): Add SUBDIR_GCC_COMPILE_SRCS.
(compile.o, compile-c-types.o, compile-c-symbols.o)
(compile-object-load.o, compile-object-run.o, compile-loc2c.o)
(compile-c-support.o): New targets.
gdb/doc/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.texinfo (Altering): Update.
(Compiling and Injecting Code): New node.
gdb/testsuite/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
Tom Tromey <tromey@redhat.com>
* configure.ac: Add gdb.compile/.
* configure: Regenerate.
* gdb.compile/Makefile.in: New file.
* gdb.compile/compile-ops.exp: New file.
* gdb.compile/compile-ops.c: New file.
* gdb.compile/compile-tls.c: New file.
* gdb.compile/compile-tls.exp: New file.
* gdb.compile/compile-constvar.S: New file.
* gdb.compile/compile-constvar.c: New file.
* gdb.compile/compile-mod.c: New file.
* gdb.compile/compile-nodebug.c: New file.
* gdb.compile/compile-setjmp-mod.c: New file.
* gdb.compile/compile-setjmp.c: New file.
* gdb.compile/compile-setjmp.exp: New file.
* gdb.compile/compile-shlib.c: New file.
* gdb.compile/compile.c: New file.
* gdb.compile/compile.exp: New file.
* lib/gdb.exp (skip_compile_feature_tests): New proc.
