From patchwork Tue Aug 26 20:31:47 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Smundak X-Patchwork-Id: 2541 Received: (qmail 16006 invoked by alias); 26 Aug 2014 20:31:51 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 15997 invoked by uid 89); 26 Aug 2014 20:31:51 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.4 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, RP_MATCHES_RCVD, SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-oi0-f52.google.com Received: from mail-oi0-f52.google.com (HELO mail-oi0-f52.google.com) (209.85.218.52) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Tue, 26 Aug 2014 20:31:49 +0000 Received: by mail-oi0-f52.google.com with SMTP id g201so2176651oib.11 for ; Tue, 26 Aug 2014 13:31:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=71h6IVGA0daYUBbotzvIbO4zOuxPLHpS0/l6HrLkP1Q=; b=QH4bBmf830/oTSc7wuEpisTZVpZvhNjoP005kzNpio45kN9m9cLD6kZ+rd0jk9y3WS mUmNL4fRYt1FLoVGQ+ByjEIU6z0QcxLSn5zuCt8HdP9fz1k2zupnzsKjmTZU3Wxzqyv+ Dc4w0NKJ4udkhNDPZHBiiZau6c0lh4DItAEltKJ3cNX+rSrU1SOqlzAVtjpd0uHY81Zo 6wJZMnW+xwrY7uFBK9Ggq8YnRT8bcLxslrMReZOrKxPMABQxK2fyp6unDvXWZo3PhkDw Ldgw9rr11jOe++P5AMK9HpFg5ikLm/5UJAA+BnG9SeU/75QXQNJ7RT3G//FXJ+RmtEd+ mSIw== X-Gm-Message-State: ALoCoQmZrzC8j8VAG/dsd/IWTiRO38/dV8fvoPXqaGjfoO/AFlPdJAOwNqEpX2/8PUYpsrW/Q56o MIME-Version: 1.0 X-Received: by 10.182.236.225 with SMTP id ux1mr15872137obc.57.1409085107332; Tue, 26 Aug 2014 13:31:47 -0700 (PDT) Received: by 10.182.84.169 with HTTP; Tue, 26 Aug 2014 13:31:47 -0700 (PDT) In-Reply-To: <21494.15883.93664.480097@ruffy2.mtv.corp.google.com> References: <83oay128ca.fsf@gnu.org> <87ioo7uuqm.fsf@fleche.redhat.com> <21494.15883.93664.480097@ruffy2.mtv.corp.google.com> Date: Tue, 26 Aug 2014 13:31:47 -0700 Message-ID: Subject: Re: [PATCH] Add Frame.read_register to Python API From: Alexander Smundak To: Doug Evans Cc: gdb-patches I've fixed the problems you pointed out, please take another look. Sasha The ability to read registers is needed to use Frame Filter API to display the frames created by JIT compilers. gdb/Changelog 2014-08-26 Sasha Smundak * python/py-frame.c (frapy_read_register): New function. 2014-08-26 Sasha Smundak * python.texi (Frames in Python): Add read_register description. 2014-08-26 Sasha Smundak * gdb.python/py-frame.exp: Test Frame.read_register. diff --git a/gdb/NEWS b/gdb/NEWS index d603cf7..46c6a87 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -3,6 +3,9 @@ *** Changes since GDB 7.8 +* Python Scripting + You can now access frame registers from Python scripts. + * On resume, GDB now always passes the signal the program had stopped for to the thread the signal was sent to, even if the user changed threads before resuming. Previously GDB would often (but not diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi index 4688783..3cb6bf8 100644 --- a/gdb/doc/python.texi +++ b/gdb/doc/python.texi @@ -3589,6 +3589,13 @@ Return the frame's symtab and line object. @xref{Symbol Tables In Python}. @end defun +@defun Frame.read_register (register) +Return the value of @var{register} in this frame. The @var{register} +argument must be a string (e.g., @code{'sp'} or @code{'rax'}). +Returns a @code{Gdb.Value} object. Throws an exception if @var{register} +does not exist. +@end defun + @defun Frame.read_var (variable @r{[}, block@r{]}) Return the value of @var{variable} in this frame. If the optional argument @var{block} is provided, search for the variable from that diff --git a/gdb/python/py-frame.c b/gdb/python/py-frame.c index 120e147..88e9114 100644 --- a/gdb/python/py-frame.c +++ b/gdb/python/py-frame.c @@ -28,6 +28,7 @@ #include "python-internal.h" #include "symfile.h" #include "objfiles.h" +#include "user-regs.h" typedef struct { PyObject_HEAD @@ -235,6 +236,40 @@ frapy_pc (PyObject *self, PyObject *args) return gdb_py_long_from_ulongest (pc); } +/* Implementation of gdb.Frame.read_register (self, register) -> gdb.Value. + Returns the value of a register in this frame. */ + +static PyObject * +frapy_read_register (PyObject *self, PyObject *args) +{ + volatile struct gdb_exception except; + const char *regnum_str; + struct value *val = NULL; + + if (!PyArg_ParseTuple (args, "s", ®num_str)) + return NULL; + + TRY_CATCH (except, RETURN_MASK_ALL) + { + struct frame_info *frame; + int regnum = -1; + + FRAPY_REQUIRE_VALID (self, frame); + + regnum = user_reg_map_name_to_regnum (get_frame_arch (frame), + regnum_str, + strlen (regnum_str)); + if (regnum >= 0) + val = value_of_register (regnum, frame); + + if (val == NULL) + PyErr_SetString (PyExc_ValueError, _("Unknown register.")); + } + GDB_PY_HANDLE_EXCEPTION (except); + + return val == NULL ? NULL : value_to_value_object (val); +} + /* Implementation of gdb.Frame.block (self) -> gdb.Block. Returns the frame's code block. */ @@ -674,6 +709,9 @@ Return the reason why it's not possible to find frames older than this." }, { "pc", frapy_pc, METH_NOARGS, "pc () -> Long.\n\ Return the frame's resume address." }, + { "read_register", frapy_read_register, METH_VARARGS, + "read_register (register_name) -> gdb.Value\n\ +Return the value of the register in the frame." }, { "block", frapy_block, METH_NOARGS, "block () -> gdb.Block.\n\ Return the frame's code block." }, diff --git a/gdb/testsuite/gdb.python/py-frame.exp b/gdb/testsuite/gdb.python/py-frame.exp index 3517824..e47f340 100644 --- a/gdb/testsuite/gdb.python/py-frame.exp +++ b/gdb/testsuite/gdb.python/py-frame.exp @@ -94,3 +94,20 @@ gdb_test "python print ('result = %s' % f0.read_var ('variable_which_surely_does gdb_test "python print ('result = %s' % f0.read_var ('a'))" " = 1" "test Frame.read_var - success" gdb_test "python print ('result = %s' % (gdb.selected_frame () == f1))" " = True" "test gdb.selected_frame" + +# Can read SP register. +gdb_test "python print ('result = %s' % (gdb.selected_frame ().read_register ('sp') == gdb.parse_and_eval ('\$sp')))" \ + " = True" \ + "test Frame.read_register(sp)" + +# PC value obtained via read_register is as expected. +gdb_test "python print ('result = %s' % (f0.read_register('pc') == f0.pc()))" \ + " = True" \ + "test Frame.read_register(pc)" + +# On x86-64, PC is in $rip register. +if {[istarget x86_64-*]} { + gdb_test "python print ('result = %s' % (f0.read_register('pc') == f0.read_register('rip')))" \ + " = True" \ + "test Frame.read_register(rip)" +}