From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by sourceware.org (Postfix) with ESMTPS id 9F5953858C60 for ; Thu, 2 Feb 2023 13:54:40 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 9F5953858C60 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 8E02D1FDA3; Thu, 2 Feb 2023 13:54:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1675346079; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hsyfG9/50q5AUt8U8VOND1pRsXlpWB3QPpyUEZx2Nio=; b=nu+aWprvPbcTp4sM4esAIfSV+awfyBMDyyRYpp7HhFO2OCj+4RDKaAIVnNr0JuW/VU0qna 8WD35lLwWw4poQ0dVVQyrcWlK+ZWG7Oj336rzuyiNM7cw3p/SZBLdMBz+61l4mAGBYEPfY g4JYcShpdo1AWlo4bbuuwJINu6yRTZ0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1675346079; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hsyfG9/50q5AUt8U8VOND1pRsXlpWB3QPpyUEZx2Nio=; b=vy+1hRFWUYPeJccfL2rsxcfcbViBet3c0ZeeYeztzmNuY57F6qHqHia8yL6ysM1buLRW3F zpWXjMaHcm39dBBA== Received: from wotan.suse.de (wotan.suse.de [10.160.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 5A03B2C141; Thu, 2 Feb 2023 13:54:39 +0000 (UTC) Date: Thu, 2 Feb 2023 13:54:39 +0000 (UTC) From: Richard Biener To: Qing Zhao cc: "gcc-patches@gcc.gnu.org" , "siddhesh@gotplt.org" , "keescook@chromium.org" Subject: Re: [PATCH 1/2] Handle component_ref to a structre/union field including flexible array member [PR101832] In-Reply-To: Message-ID: References: <20230131141140.3610133-1-qing.zhao@oracle.com> <20230131141140.3610133-2-qing.zhao@oracle.com> <812910BC-870E-4432-870D-538024F1A510@oracle.com> User-Agent: Alpine 2.22 (LSU 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Status: No, score=-11.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Thu, 2 Feb 2023, Qing Zhao wrote: > > > > On Feb 2, 2023, at 3:07 AM, Richard Biener wrote: > > > > On Wed, 1 Feb 2023, Qing Zhao wrote: > > > >> > >> > >>> On Feb 1, 2023, at 6:41 AM, Richard Biener wrote: > >>> > >>> On Tue, 31 Jan 2023, Qing Zhao wrote: > >>> > >>>> GCC extension accepts the case when a struct with a flexible array member > >>>> is embedded into another struct (possibly recursively). > >>>> __builtin_object_size should treat such struct as flexible size per > >>>> -fstrict-flex-arrays. > >>>> > >>>> PR tree-optimization/101832 > >>>> > >>>> gcc/ChangeLog: > >>>> > >>>> PR tree-optimization/101832 > >>>> * tree-object-size.cc (flexible_size_type_p): New function. > >>>> (addr_object_size): Handle structure/union type when it has > >>>> flexible size. > >>>> > >>>> gcc/testsuite/ChangeLog: > >>>> > >>>> PR tree-optimization/101832 > >>>> * gcc.dg/builtin-object-size-pr101832-2.c: New test. > >>>> * gcc.dg/builtin-object-size-pr101832-3.c: New test. > >>>> * gcc.dg/builtin-object-size-pr101832-4.c: New test. > >>>> * gcc.dg/builtin-object-size-pr101832.c: New test. > >>>> --- > >>>> .../gcc.dg/builtin-object-size-pr101832-2.c | 135 ++++++++++++++++++ > >>>> .../gcc.dg/builtin-object-size-pr101832-3.c | 135 ++++++++++++++++++ > >>>> .../gcc.dg/builtin-object-size-pr101832-4.c | 135 ++++++++++++++++++ > >>>> .../gcc.dg/builtin-object-size-pr101832.c | 119 +++++++++++++++ > >>>> gcc/tree-object-size.cc | 115 +++++++++++---- > >>>> 5 files changed, 611 insertions(+), 28 deletions(-) > >>>> create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-pr101832-2.c > >>>> create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-pr101832-3.c > >>>> create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-pr101832-4.c > >>>> create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-pr101832.c > >>>> > >>>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-2.c b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-2.c > >>>> new file mode 100644 > >>>> index 00000000000..f38babc5415 > >>>> --- /dev/null > >>>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-2.c > >>>> @@ -0,0 +1,135 @@ > >>>> +/* PR 101832: > >>>> + GCC extension accepts the case when a struct with a flexible array member > >>>> + is embedded into another struct (possibly recursively). > >>>> + __builtin_object_size will treat such struct as flexible size per > >>>> + -fstrict-flex-arrays. */ > >>>> +/* { dg-do run } */ > >>>> +/* { dg-options "-O2 -fstrict-flex-arrays=1" } */ > >>>> + > >>>> +#include > >>>> + > >>>> +unsigned n_fails = 0; > >>>> + > >>>> +#define expect(p, _v) do { \ > >>>> + size_t v = _v; \ > >>>> + if (p == v) \ > >>>> + printf("ok: %s == %zd\n", #p, p); \ > >>>> + else {\ > >>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \ > >>>> + n_fails++; \ > >>>> + } \ > >>>> +} while (0); > >>>> + > >>>> +struct A { > >>>> + int n; > >>>> + char data[];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B { > >>>> + int m; > >>>> + struct A a; > >>>> +}; > >>>> + > >>>> +struct C { > >>>> + int q; > >>>> + struct B b; > >>>> +}; > >>>> + > >>>> +struct A0 { > >>>> + int n; > >>>> + char data[0];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B0 { > >>>> + int m; > >>>> + struct A0 a; > >>>> +}; > >>>> + > >>>> +struct C0 { > >>>> + int q; > >>>> + struct B0 b; > >>>> +}; > >>>> + > >>>> +struct A1 { > >>>> + int n; > >>>> + char data[1];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B1 { > >>>> + int m; > >>>> + struct A1 a; > >>>> +}; > >>>> + > >>>> +struct C1 { > >>>> + int q; > >>>> + struct B1 b; > >>>> +}; > >>>> + > >>>> +struct An { > >>>> + int n; > >>>> + char data[8];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct Bn { > >>>> + int m; > >>>> + struct An a; > >>>> +}; > >>>> + > >>>> +struct Cn { > >>>> + int q; > >>>> + struct Bn b; > >>>> +}; > >>>> + > >>>> +volatile void *magic1, *magic2; > >>>> + > >>>> +int main(int argc, char *argv[]) > >>>> +{ > >>>> + struct B *outer; > >>>> + struct C *outest; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outer = (void *)magic1; > >>>> + outest = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer->a, 1), -1); > >>>> + expect(__builtin_object_size(&outest->b, 1), -1); > >>>> + expect(__builtin_object_size(&outest->b.a, 1), -1); > >>>> + > >>>> + struct B0 *outer0; > >>>> + struct C0 *outest0; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outer0 = (void *)magic1; > >>>> + outest0 = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer0->a, 1), -1); > >>>> + expect(__builtin_object_size(&outest0->b, 1), -1); > >>>> + expect(__builtin_object_size(&outest0->b.a, 1), -1); > >>>> + > >>>> + struct B1 *outer1; > >>>> + struct C1 *outest1; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outer1 = (void *)magic1; > >>>> + outest1 = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer1->a, 1), -1); > >>>> + expect(__builtin_object_size(&outest1->b, 1), -1); > >>>> + expect(__builtin_object_size(&outest1->b.a, 1), -1); > >>>> + > >>>> + struct Bn *outern; > >>>> + struct Cn *outestn; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outern = (void *)magic1; > >>>> + outestn = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outern->a, 1), sizeof(outern->a)); > >>>> + expect(__builtin_object_size(&outestn->b, 1), sizeof(outestn->b)); > >>>> + expect(__builtin_object_size(&outestn->b.a, 1), sizeof(outestn->b.a)); > >>>> + > >>>> + if (n_fails > 0) > >>>> + __builtin_abort (); > >>>> + > >>>> + return 0; > >>>> +} > >>>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-3.c b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-3.c > >>>> new file mode 100644 > >>>> index 00000000000..aaae99b8d67 > >>>> --- /dev/null > >>>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-3.c > >>>> @@ -0,0 +1,135 @@ > >>>> +/* PR 101832: > >>>> + GCC extension accepts the case when a struct with a flexible array member > >>>> + is embedded into another struct (possibly recursively). > >>>> + __builtin_object_size will treat such struct as flexible size per > >>>> + -fstrict-flex-arrays. */ > >>>> +/* { dg-do run } */ > >>>> +/* { dg-options "-O2 -fstrict-flex-arrays=2" } */ > >>>> + > >>>> +#include > >>>> + > >>>> +unsigned n_fails = 0; > >>>> + > >>>> +#define expect(p, _v) do { \ > >>>> + size_t v = _v; \ > >>>> + if (p == v) \ > >>>> + printf("ok: %s == %zd\n", #p, p); \ > >>>> + else {\ > >>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \ > >>>> + n_fails++; \ > >>>> + } \ > >>>> +} while (0); > >>>> + > >>>> +struct A { > >>>> + int n; > >>>> + char data[];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B { > >>>> + int m; > >>>> + struct A a; > >>>> +}; > >>>> + > >>>> +struct C { > >>>> + int q; > >>>> + struct B b; > >>>> +}; > >>>> + > >>>> +struct A0 { > >>>> + int n; > >>>> + char data[0];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B0 { > >>>> + int m; > >>>> + struct A0 a; > >>>> +}; > >>>> + > >>>> +struct C0 { > >>>> + int q; > >>>> + struct B0 b; > >>>> +}; > >>>> + > >>>> +struct A1 { > >>>> + int n; > >>>> + char data[1];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B1 { > >>>> + int m; > >>>> + struct A1 a; > >>>> +}; > >>>> + > >>>> +struct C1 { > >>>> + int q; > >>>> + struct B1 b; > >>>> +}; > >>>> + > >>>> +struct An { > >>>> + int n; > >>>> + char data[8];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct Bn { > >>>> + int m; > >>>> + struct An a; > >>>> +}; > >>>> + > >>>> +struct Cn { > >>>> + int q; > >>>> + struct Bn b; > >>>> +}; > >>>> + > >>>> +volatile void *magic1, *magic2; > >>>> + > >>>> +int main(int argc, char *argv[]) > >>>> +{ > >>>> + struct B *outer; > >>>> + struct C *outest; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outer = (void *)magic1; > >>>> + outest = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer->a, 1), -1); > >>>> + expect(__builtin_object_size(&outest->b, 1), -1); > >>>> + expect(__builtin_object_size(&outest->b.a, 1), -1); > >>>> + > >>>> + struct B0 *outer0; > >>>> + struct C0 *outest0; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outer0 = (void *)magic1; > >>>> + outest0 = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer0->a, 1), -1); > >>>> + expect(__builtin_object_size(&outest0->b, 1), -1); > >>>> + expect(__builtin_object_size(&outest0->b.a, 1), -1); > >>>> + > >>>> + struct B1 *outer1; > >>>> + struct C1 *outest1; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outer1 = (void *)magic1; > >>>> + outest1 = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer1->a, 1), sizeof(outer1->a)); > >>>> + expect(__builtin_object_size(&outest1->b, 1), sizeof(outest1->b)); > >>>> + expect(__builtin_object_size(&outest1->b.a, 1), sizeof(outest1->b.a)); > >>>> + > >>>> + struct Bn *outern; > >>>> + struct Cn *outestn; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outern = (void *)magic1; > >>>> + outestn = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outern->a, 1), sizeof(outern->a)); > >>>> + expect(__builtin_object_size(&outestn->b, 1), sizeof(outestn->b)); > >>>> + expect(__builtin_object_size(&outestn->b.a, 1), sizeof(outestn->b.a)); > >>>> + > >>>> + if (n_fails > 0) > >>>> + __builtin_abort (); > >>>> + > >>>> + return 0; > >>>> +} > >>>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-4.c b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-4.c > >>>> new file mode 100644 > >>>> index 00000000000..424264e2acd > >>>> --- /dev/null > >>>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-4.c > >>>> @@ -0,0 +1,135 @@ > >>>> +/* PR 101832: > >>>> + GCC extension accepts the case when a struct with a flexible array member > >>>> + is embedded into another struct (possibly recursively). > >>>> + __builtin_object_size will treat such struct as flexible size per > >>>> + -fstrict-flex-arrays. */ > >>>> +/* { dg-do run } */ > >>>> +/* { dg-options "-O2 -fstrict-flex-arrays=3" } */ > >>>> + > >>>> +#include > >>>> + > >>>> +unsigned n_fails = 0; > >>>> + > >>>> +#define expect(p, _v) do { \ > >>>> + size_t v = _v; \ > >>>> + if (p == v) \ > >>>> + printf("ok: %s == %zd\n", #p, p); \ > >>>> + else {\ > >>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \ > >>>> + n_fails++; \ > >>>> + } \ > >>>> +} while (0); > >>>> + > >>>> +struct A { > >>>> + int n; > >>>> + char data[];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B { > >>>> + int m; > >>>> + struct A a; > >>>> +}; > >>>> + > >>>> +struct C { > >>>> + int q; > >>>> + struct B b; > >>>> +}; > >>>> + > >>>> +struct A0 { > >>>> + int n; > >>>> + char data[0];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B0 { > >>>> + int m; > >>>> + struct A0 a; > >>>> +}; > >>>> + > >>>> +struct C0 { > >>>> + int q; > >>>> + struct B0 b; > >>>> +}; > >>>> + > >>>> +struct A1 { > >>>> + int n; > >>>> + char data[1];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B1 { > >>>> + int m; > >>>> + struct A1 a; > >>>> +}; > >>>> + > >>>> +struct C1 { > >>>> + int q; > >>>> + struct B1 b; > >>>> +}; > >>>> + > >>>> +struct An { > >>>> + int n; > >>>> + char data[8];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct Bn { > >>>> + int m; > >>>> + struct An a; > >>>> +}; > >>>> + > >>>> +struct Cn { > >>>> + int q; > >>>> + struct Bn b; > >>>> +}; > >>>> + > >>>> +volatile void *magic1, *magic2; > >>>> + > >>>> +int main(int argc, char *argv[]) > >>>> +{ > >>>> + struct B *outer; > >>>> + struct C *outest; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outer = (void *)magic1; > >>>> + outest = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer->a, 1), -1); > >>>> + expect(__builtin_object_size(&outest->b, 1), -1); > >>>> + expect(__builtin_object_size(&outest->b.a, 1), -1); > >>>> + > >>>> + struct B0 *outer0; > >>>> + struct C0 *outest0; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outer0 = (void *)magic1; > >>>> + outest0 = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer0->a, 1), sizeof(outer0->a)); > >>>> + expect(__builtin_object_size(&outest0->b, 1), sizeof(outest0->b)); > >>>> + expect(__builtin_object_size(&outest0->b.a, 1), sizeof(outest0->b.a)); > >>>> + > >>>> + struct B1 *outer1; > >>>> + struct C1 *outest1; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outer1 = (void *)magic1; > >>>> + outest1 = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer1->a, 1), sizeof(outer1->a)); > >>>> + expect(__builtin_object_size(&outest1->b, 1), sizeof(outest1->b)); > >>>> + expect(__builtin_object_size(&outest1->b.a, 1), sizeof(outest1->b.a)); > >>>> + > >>>> + struct Bn *outern; > >>>> + struct Cn *outestn; > >>>> + > >>>> + /* Make sure optimization can't find some other object size. */ > >>>> + outern = (void *)magic1; > >>>> + outestn = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outern->a, 1), sizeof(outern->a)); > >>>> + expect(__builtin_object_size(&outestn->b, 1), sizeof(outestn->b)); > >>>> + expect(__builtin_object_size(&outestn->b.a, 1), sizeof(outestn->b.a)); > >>>> + > >>>> + if (n_fails > 0) > >>>> + __builtin_abort (); > >>>> + > >>>> + return 0; > >>>> +} > >>>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-pr101832.c b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832.c > >>>> new file mode 100644 > >>>> index 00000000000..8ed6980edf0 > >>>> --- /dev/null > >>>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832.c > >>>> @@ -0,0 +1,119 @@ > >>>> +/* PR 101832: > >>>> + GCC extension accepts the case when a struct with a flexible array member > >>>> + is embedded into another struct (possibly recursively). > >>>> + __builtin_object_size will treat such struct as flexible size per > >>>> + -fstrict-flex-arrays. */ > >>>> +/* { dg-do run } */ > >>>> +/* { dg-options "-O2" } */ > >>>> + > >>>> +#include > >>>> + > >>>> +unsigned n_fails = 0; > >>>> + > >>>> +#define expect(p, _v) do { \ > >>>> + size_t v = _v; \ > >>>> + if (p == v) \ > >>>> + printf("ok: %s == %zd\n", #p, p); \ > >>>> + else {\ > >>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \ > >>>> + n_fails++; \ > >>>> + } \ > >>>> +} while (0); > >>>> + > >>>> +struct A { > >>>> + int n; > >>>> + char data[];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B { > >>>> + int m; > >>>> + struct A a; > >>>> +}; > >>>> + > >>>> +struct C { > >>>> + int q; > >>>> + struct B b; > >>>> +}; > >>>> + > >>>> +struct A0 { > >>>> + int n; > >>>> + char data[0];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B0 { > >>>> + int m; > >>>> + struct A0 a; > >>>> +}; > >>>> + > >>>> +struct C0 { > >>>> + int q; > >>>> + struct B0 b; > >>>> +}; > >>>> + > >>>> +struct A1 { > >>>> + int n; > >>>> + char data[1];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct B1 { > >>>> + int m; > >>>> + struct A1 a; > >>>> +}; > >>>> + > >>>> +struct C1 { > >>>> + int q; > >>>> + struct B1 b; > >>>> +}; > >>>> + > >>>> +struct An { > >>>> + int n; > >>>> + char data[8];/* Content following header */ > >>>> +}; > >>>> + > >>>> +struct Bn { > >>>> + int m; > >>>> + struct An a; > >>>> +}; > >>>> + > >>>> +struct Cn { > >>>> + int q; > >>>> + struct Bn b; > >>>> +}; > >>>> + > >>>> +volatile void *magic1, *magic2; > >>>> + > >>>> +int main(int argc, char *argv[]) > >>>> +{ > >>>> + struct B *outer = (void *)magic1; > >>>> + struct C *outest = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer->a, 1), -1); > >>>> + expect(__builtin_object_size(&outest->b, 1), -1); > >>>> + expect(__builtin_object_size(&outest->b.a, 1), -1); > >>>> + > >>>> + struct B0 *outer0 = (void *)magic1; > >>>> + struct C0 *outest0 = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer0->a, 1), -1); > >>>> + expect(__builtin_object_size(&outest0->b, 1), -1); > >>>> + expect(__builtin_object_size(&outest0->b.a, 1), -1); > >>>> + > >>>> + struct B1 *outer1 = (void *)magic1; > >>>> + struct C1 *outest1 = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outer1->a, 1), -1); > >>>> + expect(__builtin_object_size(&outest1->b, 1), -1); > >>>> + expect(__builtin_object_size(&outest1->b.a, 1), -1); > >>>> + > >>>> + struct Bn *outern = (void *)magic1; > >>>> + struct Cn *outestn = (void *)magic2; > >>>> + > >>>> + expect(__builtin_object_size(&outern->a, 1), -1); > >>>> + expect(__builtin_object_size(&outestn->b, 1), -1); > >>>> + expect(__builtin_object_size(&outestn->b.a, 1), -1); > >>>> + > >>>> + if (n_fails > 0) > >>>> + __builtin_abort (); > >>>> + > >>>> + return 0; > >>>> +} > >>>> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc > >>>> index 9a936a91983..56b78ca2a8c 100644 > >>>> --- a/gcc/tree-object-size.cc > >>>> +++ b/gcc/tree-object-size.cc > >>>> @@ -500,6 +500,42 @@ decl_init_size (tree decl, bool min) > >>>> return size; > >>>> } > >>>> > >>>> +/* Determine whether TYPE is a structure with a flexible array member > >>>> + per -fstrict-flex-array or a union containing such a structure > >>>> + (possibly recursively). */ > >>>> +static bool > >>>> +flexible_size_type_p (const_tree type) > >>>> +{ > >>>> + tree x = NULL_TREE; > >>>> + tree last = NULL_TREE; > >>>> + switch (TREE_CODE (type)) > >>>> + { > >>>> + case RECORD_TYPE: > >>>> + for (x = TYPE_FIELDS (type); x != NULL_TREE; x = DECL_CHAIN (x)) > >>>> + if (TREE_CODE (x) == FIELD_DECL) > >>>> + last = x; > >>>> + if (last == NULL_TREE) > >>>> + return false; > >>>> + if (TREE_CODE (TREE_TYPE (last)) == ARRAY_TYPE > >>>> + && !DECL_NOT_FLEXARRAY (last)) > >>>> + return true; > >>>> + else if (TREE_CODE (TREE_TYPE (last)) == RECORD_TYPE > >>>> + || TREE_CODE (TREE_TYPE (last)) == UNION_TYPE) > >>>> + return flexible_size_type_p (TREE_TYPE (last)); > >>> > >>> For types with many members this can become quite slow (IIRC we had > >>> bugs about similar walks of all fields in types), and this function > >>> looks like it's invoked multiple times on the same type per TU. > >>> > >>> In principle the property is fixed at the time we lay out a record > >>> type, so we might want to compute it at that time and record the > >>> result. > >> > >> You mean in FE? > > > > Yes, either in the frontend or in the middle-ends layout_type. > > > >> Yes, that?s better and cleaner. > >> > >> I will add one more field in the TYPE structure to record this information and check this field during middle end. > >> > >> I had the same thought in the beginning, but not sure whether adding a > >> new field in IR is necessary or not, other places in middle end might > >> not use this new field. > > > > It might be interesting to search for other code walking all fields of > > a type to determine this or similar info. > > There is one which is defined in tree.cc but only is referenced in c/c-decl.cc: > > /* Determine whether TYPE is a structure with a flexible array member, > or a union containing such a structure (possibly recursively). */ > flexible_array_type_p > > However, this routine is a little different than the one I tried to add: > > In the current routine ?flexible_array_type_p?, only one level nesting in the structure is accepted, multiple nesting in structure is not permitted. > > So, my question is: shall we accept multiple nesting in structure? i.e. If we don't reject the testcase with an error, then yes. > struct A { > int n; > char data[];/* Content following header */ > }; > > struct B { > int m; > struct A a; > }; > > struct C { > int q; > struct B b; > }; > > Qing > > > >> thanks. > >> > >> Qing > >> > >>> > >>>> + return false; > >>>> + case UNION_TYPE: > >>>> + for (x = TYPE_FIELDS (type); x != NULL_TREE; x = DECL_CHAIN (x)) > >>>> + { > >>>> + if (TREE_CODE (x) == FIELD_DECL > >>>> + && flexible_array_type_p (TREE_TYPE (x))) > >>>> + return true; > >>>> + } > >>>> + return false; > >>>> + default: > >>>> + return false; > >>>> + } > >>>> +} > >>>> + > >>>> /* Compute __builtin_object_size for PTR, which is a ADDR_EXPR. > >>>> OBJECT_SIZE_TYPE is the second argument from __builtin_object_size. > >>>> If unknown, return size_unknown (object_size_type). */ > >>>> @@ -633,45 +669,68 @@ addr_object_size (struct object_size_info *osi, const_tree ptr, > >>>> v = NULL_TREE; > >>>> break; > >>>> case COMPONENT_REF: > >>>> - if (TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE) > >>>> + /* When the ref is not to an array, a record or a union, it > >>>> + will not have flexible size, compute the object size > >>>> + directly. */ > >>>> + if ((TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE) > >>>> + && (TREE_CODE (TREE_TYPE (v)) != RECORD_TYPE) > >>>> + && (TREE_CODE (TREE_TYPE (v)) != UNION_TYPE)) > >>>> { > >>>> v = NULL_TREE; > >>>> break; > >>>> } > >>>> - is_flexible_array_mem_ref = array_ref_flexible_size_p (v); > >>>> - while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) > >>>> - if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> - != UNION_TYPE > >>>> - && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> - != QUAL_UNION_TYPE) > >>>> - break; > >>>> - else > >>>> - v = TREE_OPERAND (v, 0); > >>>> - if (TREE_CODE (v) == COMPONENT_REF > >>>> - && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> - == RECORD_TYPE) > >>>> + /* if the record or union does not have flexible size > >>>> + compute the object size directly. */ > >>>> + if (TREE_CODE (TREE_TYPE (v)) == RECORD_TYPE > >>>> + || TREE_CODE (TREE_TYPE (v)) == UNION_TYPE) > >>>> { > >>>> - /* compute object size only if v is not a > >>>> - flexible array member. */ > >>>> - if (!is_flexible_array_mem_ref) > >>>> + if (!flexible_size_type_p (TREE_TYPE (v))) > >>>> { > >>>> v = NULL_TREE; > >>>> break; > >>>> } > >>>> - v = TREE_OPERAND (v, 0); > >>>> + else > >>>> + v = TREE_OPERAND (v, 0); > >>>> } > >>>> - while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) > >>>> - if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> - != UNION_TYPE > >>>> - && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> - != QUAL_UNION_TYPE) > >>>> - break; > >>>> - else > >>>> - v = TREE_OPERAND (v, 0); > >>>> - if (v != pt_var) > >>>> - v = NULL_TREE; > >>>> else > >>>> - v = pt_var; > >>>> + { > >>>> + /* Now the ref is to an array type. */ > >>>> + is_flexible_array_mem_ref > >>>> + = array_ref_flexible_size_p (v); > >>>> + while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) > >>>> + if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> + != UNION_TYPE > >>>> + && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> + != QUAL_UNION_TYPE) > >>>> + break; > >>>> + else > >>>> + v = TREE_OPERAND (v, 0); > >>>> + if (TREE_CODE (v) == COMPONENT_REF > >>>> + && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> + == RECORD_TYPE) > >>>> + { > >>>> + /* compute object size only if v is not a > >>>> + flexible array member. */ > >>>> + if (!is_flexible_array_mem_ref) > >>>> + { > >>>> + v = NULL_TREE; > >>>> + break; > >>>> + } > >>>> + v = TREE_OPERAND (v, 0); > >>>> + } > >>>> + while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) > >>>> + if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> + != UNION_TYPE > >>>> + && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) > >>>> + != QUAL_UNION_TYPE) > >>>> + break; > >>>> + else > >>>> + v = TREE_OPERAND (v, 0); > >>>> + if (v != pt_var) > >>>> + v = NULL_TREE; > >>>> + else > >>>> + v = pt_var; > >>>> + } > >>>> break; > >>>> default: > >>>> v = pt_var; > >>>> > >>> > >>> -- > >>> Richard Biener > >>> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, > >>> Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman; > >>> HRB 36809 (AG Nuernberg) > >> > >> > > > > -- > > Richard Biener > > SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, > > Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman; > > HRB 36809 (AG Nuernberg) > > -- Richard Biener SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman; HRB 36809 (AG Nuernberg)