From patchwork Fri Dec 20 16:47:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Simon Marchi (Code Review)" X-Patchwork-Id: 37028 Received: (qmail 19668 invoked by alias); 20 Dec 2019 16:47:37 -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 19554 invoked by uid 89); 20 Dec 2019 16:47:35 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3 autolearn=ham version=3.3.1 spammy=destruction, internal_error, Reserve X-HELO: mx1.osci.io Received: from polly.osci.io (HELO mx1.osci.io) (8.43.85.229) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 20 Dec 2019 16:47:32 +0000 Received: by mx1.osci.io (Postfix, from userid 994) id 9D1AF20489; Fri, 20 Dec 2019 11:47:28 -0500 (EST) Received: from gnutoolchain-gerrit.osci.io (gnutoolchain-gerrit.osci.io [IPv6:2620:52:3:1:5054:ff:fe06:16ca]) by mx1.osci.io (Postfix) with ESMTP id E95BD2064A; Fri, 20 Dec 2019 11:47:08 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by gnutoolchain-gerrit.osci.io (Postfix) with ESMTP id DAD96281DA; Fri, 20 Dec 2019 11:47:08 -0500 (EST) X-Gerrit-PatchSet: 3 Date: Fri, 20 Dec 2019 11:47:08 -0500 From: "Sourceware to Gerrit sync (Code Review)" To: Tankut Baris Aktemur , gdb-patches@sourceware.org Cc: Tom Tromey Auto-Submitted: auto-generated X-Gerrit-MessageType: merged Subject: [pushed] infcall: handle pass-by-reference arguments appropriately X-Gerrit-Change-Id: I18fa5d0df814dfa0defe9e862a88a6dbf1d99d01 X-Gerrit-Change-Number: 141 X-Gerrit-ChangeURL: X-Gerrit-Commit: 099a6354dab7e74c990501929f383394fc8efd02 In-Reply-To: References: Reply-To: noreply@gnutoolchain-gerrit.osci.io, tankut.baris.aktemur@intel.com, tromey@sourceware.org, gdb-patches@sourceware.org MIME-Version: 1.0 Content-Disposition: inline User-Agent: Gerrit/3.0.3-79-g83ff7f88f1 Message-Id: <20191220164708.DAD96281DA@gnutoolchain-gerrit.osci.io> Sourceware to Gerrit sync has submitted this change. Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/141 ...................................................................... infcall: handle pass-by-reference arguments appropriately If an aggregate argument is implicitly pass-by-reference, allocate a temporary object on the stack, initialize it via the copy constructor (if exists) or trivially by memcpy'ing. Pass the reference of the temporary to the callee function. After the callee returns, invoke the destructor of the temporary. gdb/ChangeLog: 2019-12-20 Tankut Baris Aktemur PR gdb/25054 * infcall.c (call_function_by_hand_dummy): Update the argument- passing section for call-by-value parameters. (struct destructor_info): New struct. (call_destructors): New auxiliary function. Change-Id: I18fa5d0df814dfa0defe9e862a88a6dbf1d99d01 --- M gdb/ChangeLog M gdb/infcall.c 2 files changed, 132 insertions(+), 3 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 43b86f2..c2157e4 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,13 @@ 2019-12-20 Tankut Baris Aktemur + PR gdb/25054 + * infcall.c (call_function_by_hand_dummy): Update the argument- + passing section for call-by-value parameters. + (struct destructor_info): New struct. + (call_destructors): New auxiliary function. + +2019-12-20 Tankut Baris Aktemur + * gnu-v3-abi.c (enum definition_style): New enum type. (get_def_style): New function. (is_user_provided_def): New function. diff --git a/gdb/infcall.c b/gdb/infcall.c index f3664d5..b6b617a 100644 --- a/gdb/infcall.c +++ b/gdb/infcall.c @@ -42,6 +42,7 @@ #include "thread-fsm.h" #include #include "gdbsupport/scope-exit.h" +#include /* If we can't find a function's name from its address, we print this instead. */ @@ -704,6 +705,33 @@ return addr; } +/* The data structure which keeps a destructor function and + its implicit 'this' parameter. */ + +struct destructor_info +{ + destructor_info (struct value *function, struct value *self) + : function (function), self (self) { } + + struct value *function; + struct value *self; +}; + + +/* Auxiliary function that takes a list of destructor functions + with their 'this' parameters, and invokes the functions. */ + +static void +call_destructors (const std::list &dtors_to_invoke, + struct type *default_return_type) +{ + for (auto vals : dtors_to_invoke) + { + call_function_by_hand (vals.function, default_return_type, + gdb::make_array_view (&(vals.self), 1)); + } +} + /* See infcall.h. */ struct value * @@ -983,6 +1011,12 @@ internal_error (__FILE__, __LINE__, _("bad switch")); } + /* Coerce the arguments and handle pass-by-reference. + We want to remember the destruction required for pass-by-ref values. + For these, store the dtor function and the 'this' argument + in DTORS_TO_INVOKE. */ + std::list dtors_to_invoke; + for (int i = args.size () - 1; i >= 0; i--) { int prototyped; @@ -1017,12 +1051,95 @@ else param_type = NULL; + value *original_arg = args[i]; args[i] = value_arg_coerce (gdbarch, args[i], param_type, prototyped); - if (param_type != NULL - && !(language_pass_by_reference (param_type).trivially_copyable)) - args[i] = value_addr (args[i]); + if (param_type == NULL) + continue; + + auto info = language_pass_by_reference (param_type); + if (!info.copy_constructible) + error (_("expression cannot be evaluated because the type '%s' " + "is not copy constructible"), TYPE_NAME (param_type)); + + if (!info.destructible) + error (_("expression cannot be evaluated because the type '%s' " + "is not destructible"), TYPE_NAME (param_type)); + + if (info.trivially_copyable) + continue; + + /* Make a copy of the argument on the stack. If the argument is + trivially copy ctor'able, copy bit by bit. Otherwise, call + the copy ctor to initialize the clone. */ + CORE_ADDR addr = reserve_stack_space (param_type, sp); + value *clone + = value_from_contents_and_address (param_type, nullptr, addr); + push_thread_stack_temporary (call_thread.get (), clone); + value *clone_ptr + = value_from_pointer (lookup_pointer_type (param_type), addr); + + if (info.trivially_copy_constructible) + { + int length = TYPE_LENGTH (param_type); + write_memory (addr, value_contents (args[i]), length); + } + else + { + value *copy_ctor; + value *cctor_args[2] = { clone_ptr, original_arg }; + find_overload_match (gdb::make_array_view (cctor_args, 2), + TYPE_NAME (param_type), METHOD, + &clone_ptr, nullptr, ©_ctor, nullptr, + nullptr, 0, EVAL_NORMAL); + + if (copy_ctor == nullptr) + error (_("expression cannot be evaluated because a copy " + "constructor for the type '%s' could not be found " + "(maybe inlined?)"), TYPE_NAME (param_type)); + + call_function_by_hand (copy_ctor, default_return_type, + gdb::make_array_view (cctor_args, 2)); + } + + /* If the argument has a destructor, remember it so that we + invoke it after the infcall is complete. */ + if (!info.trivially_destructible) + { + /* Looking up the function via overload resolution does not + work because the compiler (in particular, gcc) adds an + artificial int parameter in some cases. So we look up + the function by using the "~" name. This should be OK + because there can be only one dtor definition. */ + const char *dtor_name = nullptr; + for (int fieldnum = 0; + fieldnum < TYPE_NFN_FIELDS (param_type); + fieldnum++) + { + fn_field *fn + = TYPE_FN_FIELDLIST1 (param_type, fieldnum); + const char *field_name + = TYPE_FN_FIELDLIST_NAME (param_type, fieldnum); + + if (field_name[0] == '~') + dtor_name = TYPE_FN_FIELD_PHYSNAME (fn, 0); + } + + if (dtor_name == nullptr) + error (_("expression cannot be evaluated because a destructor " + "for the type '%s' could not be found " + "(maybe inlined?)"), TYPE_NAME (param_type)); + + value *dtor + = find_function_in_inferior (dtor_name, 0); + + /* Insert the dtor to the front of the list to call them + in reverse order later. */ + dtors_to_invoke.emplace_front (dtor, clone_ptr); + } + + args[i] = clone_ptr; } /* Reserve space for the return structure to be written on the @@ -1189,6 +1306,10 @@ maybe_remove_breakpoints (); gdb_assert (retval != NULL); + + /* Destruct the pass-by-ref argument clones. */ + call_destructors (dtors_to_invoke, default_return_type); + return retval; }