From patchwork Wed Oct 23 19:13:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Burgess X-Patchwork-Id: 35264 Received: (qmail 13871 invoked by alias); 23 Oct 2019 19:14:02 -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 13853 invoked by uid 89); 23 Oct 2019 19:14:01 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-22.5 required=5.0 tests=AWL, BAYES_05, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_STOCKGEN, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.1 spammy=D*r, Grab, U*simark, simarksimarkca X-HELO: mail-wr1-f50.google.com Received: from mail-wr1-f50.google.com (HELO mail-wr1-f50.google.com) (209.85.221.50) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 23 Oct 2019 19:13:58 +0000 Received: by mail-wr1-f50.google.com with SMTP id l10so22891456wrb.2 for ; Wed, 23 Oct 2019 12:13:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=embecosm.com; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Xtgq6AxoTmHwrM83VAXQem/7L6ZJJeb/o1BaTypJqKI=; b=G3Y7dhPUztU0ghyIU7t7pOl3oQ277aTqIIlRwoBeTXQekb6fTcNXC5CagxQMn0LdW9 OKjvkyjh+2CF/i/8eCuLGUIsiDhVCYlsilc2sV8y8168MkeCxTogNHHYe6hCO/pBpq10 JoYBMuwRjQSS/fzkAvrWfI24O+TqaE77D+ZGp+XnrWlUzhdPNuqh9rCsVhuVAzk0jJ7B cUitLM/Q/Acv/4AMLG20muw+dtCbJEqiG7cWjE2DPDbButgGYrpzWcwJjMOzURs6yB0b Gsz3bmdHd2XAiGCWcj++s8YjnV13P8PtmckkbUScmCxHQyGwIIoaPjN5WwWHyzgxQGaM eWsg== Return-Path: Received: from localhost (host86-128-12-122.range86-128.btcentralplus.com. [86.128.12.122]) by smtp.gmail.com with ESMTPSA id x12sm13087887wru.93.2019.10.23.12.13.55 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 23 Oct 2019 12:13:55 -0700 (PDT) Date: Wed, 23 Oct 2019 20:13:54 +0100 From: Andrew Burgess To: Christian Biesinger Cc: Simon Marchi , gdb-patches Subject: Re: [PATCH] gdb/python: Introduce gdb.lookup_all_static_symbols Message-ID: <20191023191354.GH4962@embecosm.com> References: <20191015141515.GW4962@embecosm.com> <20191015164647.1837-1-andrew.burgess@embecosm.com> <32eba92d-55a9-5694-cec5-80001d8ff1ae@simark.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Fortune: Don't feed the bats tonight. X-Editor: GNU Emacs [ http://www.gnu.org/software/emacs ] User-Agent: Mutt/1.9.2 (2017-12-15) X-IsSubscribed: yes * Christian Biesinger [2019-10-21 17:36:37 -0500]: > On Tue, Oct 15, 2019 at 2:28 PM Simon Marchi wrote: > > > > On 2019-10-15 12:46 p.m., Andrew Burgess wrote: > > > If gdb.lookup_static_symbol is going to return a single symbol then it > > > makes sense (I think) for it to return a context sensitive choice of > > > symbol, that is the static symbol that would be visible to the program > > > at that point. > > > > I remember discussing this with Christian, and I didn't have a strong option. But > > now, I tend to agree with Andrew. > > > > I see two use cases here: > > > > 1. I want to get all static symbols named `foo`. In which case, I'd use the > > function Andrew proposes in this patch. > > 2. I want to get the static symbol named `foo` that's visible from a certain > > point, perhaps a given block or where my program is currently stopped at. > > Ideally, we would have a "CompilationUnit" object type in Python, such that > > I could use > > > > block.compunit.lookup_static_symbol('foo') > > > > or > > > > gdb.current_compunit().lookup_static_symbol('foo') > > So technically, those don't give you "the static symbol named `foo` > that's visible from [this] point", because there could be static > variable in the function. > > Since we already have block objects, should this new function > optionally take a block to start the lookup in? When you say "new function", I assume you mean 'gdb.lookup_static_symbol' not 'gdb.lookup_static_symbols', as the second one always returns all symbols. Anyway, I took a stab at adding a block parameter to the first of these functions - is this what you were thinking? Thanks, Andrew --- commit 62d488878b467dd83a9abffc6dc3c67c2da82e85 Author: Andrew Burgess Date: Wed Oct 23 15:08:42 2019 +0100 gdb/python: New block parameter for gdb.lookup_static_symbol Adds a new block parameter to gdb.lookup_static_symbol. Currently gdb.lookup_static_symbol first looks in the global static scope of the current block for a matching symbol, and if non is found it then looks in all other global static scopes. The new block parameter for gdb.lookup_static_symbol allows the user to search the global static scope for some other block rather than the current block if they so desire. If the block parameter is no given, or is given as None, then GDB will search using the current block first (this matches the CLI behaviour). I added the block parameter to the middle of the parameter list, so the parameter order is 'symbol block domain', this matches the order of the other symbol lookup function that takes a block 'lookup_symbol' which also has the order 'symbol block domain'. I think changing the API like this is fine as the 'gdb.lookup_static_symbol' has not been in any previous GDB release, so there should be no existing user scripts that use this function. The documentation for gdb.lookup_static_symbol has been reordered so that the block parameter can be explained early on, and I've added some tests. gdb/ChangeLog: * python/py-symbol.c (gdbpy_lookup_static_symbol): Accept and handle a new block parameter. gdb/testsuite/ChangeLog: * gdb.python/py-symbol.exp: Add tests for passing a block parameter to gdb.lookup_static_symbol. gdb/doc/ChangeLog: * python.texi (Symbols In Python): Rewrite documentation for gdb.lookup_static_symbol, including adding a description of the new block parameter. Change-Id: I132a7f0934ba029c9f32058e9341a6c7cb975606 diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi index a30c8ae4f03..fe984a06b98 100644 --- a/gdb/doc/python.texi +++ b/gdb/doc/python.texi @@ -4853,31 +4853,41 @@ @end defun @findex gdb.lookup_static_symbol -@defun gdb.lookup_static_symbol (name @r{[}, domain@r{]}) -This function searches for a global symbol with static linkage by name. -The search scope can be restricted to by the domain argument. +@defun gdb.lookup_static_symbol (name @r{[}, block @r{[}, domain@r{]]}) +This function searches for a global symbol with static linkage by +name. @var{name} is the name of the symbol. It must be a string. -The optional @var{domain} argument restricts the search to the domain type. -The @var{domain} argument must be a domain constant defined in the @code{gdb} -module and described later in this chapter. - -The result is a @code{gdb.Symbol} object or @code{None} if the symbol -is not found. - -Note that this function will not find function-scoped static variables. To look -up such variables, iterate over the variables of the function's -@code{gdb.Block} and check that @code{block.addr_class} is -@code{gdb.SYMBOL_LOC_STATIC}. There can be multiple global symbols with static linkage with the same name. This function will only return the first matching symbol that it finds. Which symbol is found depends on where @value{GDBN} is currently stopped, as @value{GDBN} will first search for matching -symbols in the current object file, and then search all other object -files. If the application is not yet running then @value{GDBN} will -search all object files in the order they appear in the debug -information. +symbols in the global static scope of the current object file, and +then search all other object files. This corresponds to the behaviour +you would see from the CLI if you tried to print the symbol by name. + +If the application is not yet running then @value{GDBN} will search +all object files in the order they appear in the debug information. + +The optional @var{domain} argument restricts the search to the domain +type. The @var{domain} argument must be a domain constant defined in +the @code{gdb} module and described later in this chapter. + +The optional @var{block} argument can be used to change which global +static scope @value{GDBN} will search first. If @var{block} is not +given, or is passed the value @code{None} then @value{GDBN} will first +search the global static scope corresponding to the current block. If +@var{block} is passed a @code{gdb.Block} then @value{GDBN} will first +search the global static scope corresponding to the supplied block. + +The result is a @code{gdb.Symbol} object or @code{None} if the symbol +is not found. + +Note that this function will not find function-scoped static +variables. To look up such variables, iterate over the variables of +the function's @code{gdb.Block} and check that @code{block.addr_class} +is @code{gdb.SYMBOL_LOC_STATIC}. @end defun @findex gdb.lookup_global_symbol diff --git a/gdb/python/py-symbol.c b/gdb/python/py-symbol.c index 647c54b0a5b..24b3f6f4376 100644 --- a/gdb/python/py-symbol.c +++ b/gdb/python/py-symbol.c @@ -473,19 +473,20 @@ gdbpy_lookup_global_symbol (PyObject *self, PyObject *args, PyObject *kw) } /* Implementation of - gdb.lookup_static_symbol (name [, domain]) -> symbol or None. */ + gdb.lookup_static_symbol (name [, block] [, domain]) -> symbol or None. */ PyObject * gdbpy_lookup_static_symbol (PyObject *self, PyObject *args, PyObject *kw) { const char *name; int domain = VAR_DOMAIN; - static const char *keywords[] = { "name", "domain", NULL }; + static const char *keywords[] = { "name", "block", "domain", NULL }; struct symbol *symbol = NULL; + PyObject *block_obj = NULL; PyObject *sym_obj; - if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|i", keywords, &name, - &domain)) + if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|O|i", keywords, &name, + &block_obj, &domain)) return NULL; /* In order to find static symbols associated with the "current" object @@ -493,16 +494,22 @@ gdbpy_lookup_static_symbol (PyObject *self, PyObject *args, PyObject *kw) we can acquire a current block. If this fails however, then we still want to search all static symbols, so don't throw an exception just yet. */ - const struct block *block = NULL; - try - { - struct frame_info *selected_frame - = get_selected_frame (_("No frame selected.")); - block = get_frame_block (selected_frame, NULL); - } - catch (const gdb_exception &except) + const struct block *block = nullptr; + if (block_obj) + block = block_object_to_block (block_obj); + + if (block == nullptr) { - /* Nothing. */ + try + { + struct frame_info *selected_frame + = get_selected_frame (_("No frame selected.")); + block = get_frame_block (selected_frame, NULL); + } + catch (const gdb_exception &except) + { + /* Nothing. */ + } } try diff --git a/gdb/testsuite/gdb.python/py-symbol.exp b/gdb/testsuite/gdb.python/py-symbol.exp index ea41297f54f..0ffe07df5a8 100644 --- a/gdb/testsuite/gdb.python/py-symbol.exp +++ b/gdb/testsuite/gdb.python/py-symbol.exp @@ -87,6 +87,10 @@ if ![runto_main] then { global hex decimal +# Grab the value of $pc, we'll use this later. +set pc_val_file_1 [get_integer_valueof "\$pc" 0 \ + "get value of \$pc in main file"] + gdb_breakpoint [gdb_get_line_number "Block break here."] gdb_continue_to_breakpoint "Block break here." gdb_py_test_silent_cmd "python frame = gdb.selected_frame()" "Get Frame" 0 @@ -116,7 +120,18 @@ gdb_test "python print (func.addr_class == gdb.SYMBOL_LOC_BLOCK)" "True" "test f gdb_breakpoint "function_in_other_file" gdb_continue_to_breakpoint "function_in_other_file" gdb_test "python print (gdb.lookup_static_symbol ('rr').value ())" "99" \ - "print value of rr from other file" + "print value of rr from other file, don't pass a block value" +gdb_test "python print (gdb.lookup_static_symbol ('rr', None).value ())" "99" \ + "print value of rr from other file, pass block value of None" + +# Test gdb.lookup_static_symbol passing a block parameter +set pc_val_file_2 [get_integer_valueof "\$pc" 0 \ + "get \$pc in other file"] +gdb_test "python print (gdb.lookup_static_symbol ('rr', gdb.current_progspace ().block_for_pc (${pc_val_file_2})).value ())" "99" \ + "print value of rr from other file, pass block for other file" +gdb_test "python print (gdb.lookup_static_symbol ('rr', gdb.current_progspace ().block_for_pc (${pc_val_file_1})).value ())" "42" \ + "print value of rr from other file, pass block for main file" + gdb_test "python print (gdb.lookup_static_symbols ('rr')\[0\].value ())" "99" \ "print value of gdb.lookup_static_symbols ('rr')\[0\], from the other file" gdb_test "python print (gdb.lookup_static_symbols ('rr')\[1\].value ())" "42" \ @@ -131,7 +146,14 @@ gdb_py_test_silent_cmd "python frame = gdb.selected_frame()" "Get Frame" 0 # Check that we find the static sybol local to this file over the # static symbol from the second source file. gdb_test "python print (gdb.lookup_static_symbol ('rr').value ())" "42" \ - "print value of rr from main file" + "print value of rr from main file, passing no block parameter" +gdb_test "python print (gdb.lookup_static_symbol ('rr', None).value ())" "42" \ + "print value of rr from main file, passing None block parameter" +gdb_test "python print (gdb.lookup_static_symbol ('rr', gdb.current_progspace ().block_for_pc (${pc_val_file_2})).value ())" "99" \ + "print value of rr from main file, pass block for other file" +gdb_test "python print (gdb.lookup_static_symbol ('rr', gdb.current_progspace ().block_for_pc (${pc_val_file_1})).value ())" "42" \ + "print value of rr from main file, pass block for main file" + gdb_test "python print (gdb.lookup_static_symbols ('rr')\[0\].value ())" "99" \ "print value of gdb.lookup_static_symbols ('rr')\[0\], from the main file" gdb_test "python print (gdb.lookup_static_symbols ('rr')\[1\].value ())" "42" \