From patchwork Thu May 4 16:00:38 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lance Richardson X-Patchwork-Id: 9712267 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6D6F360387 for ; Thu, 4 May 2017 16:17:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5E5FA2521E for ; Thu, 4 May 2017 16:17:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 531FD2861E; Thu, 4 May 2017 16:17:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AAD4A28404 for ; Thu, 4 May 2017 16:17:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751474AbdEDQCE (ORCPT ); Thu, 4 May 2017 12:02:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54824 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754572AbdEDQAk (ORCPT ); Thu, 4 May 2017 12:00:40 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D2185C04BD2B for ; Thu, 4 May 2017 16:00:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com D2185C04BD2B Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=lrichard@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com D2185C04BD2B Received: from thinkcentre.localdomain.com (ovpn-123-166.rdu2.redhat.com [10.10.123.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id 96E6617990 for ; Thu, 4 May 2017 16:00:39 +0000 (UTC) From: Lance Richardson To: linux-sparse@vger.kernel.org Subject: [PATCH v5] sparse: add support for _Static_assert Date: Thu, 4 May 2017 12:00:38 -0400 Message-Id: <20170504160038.5328-1-lrichard@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 04 May 2017 16:00:40 +0000 (UTC) Sender: linux-sparse-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sparse@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch introduces support for the C11 _Static_assert() construct. Per the N1539 draft standard, the syntax changes for this construct include: declaration: [opt] ; struct-declaration: [opt] ; static_assert-declaration: _Static_assert ( , ) ; Signed-off-by: Lance Richardson Acked-by: Luc Van Oostenryck --- v5: Incorporated feedback from Christopher Li and Luc van Oostenryck: - Made _Static_assert a reserved identifier - Simplified check for _Static_assert keyword, consolidated into a common function. - Improved the "static assert within a function body" test case by adding a static assertion intermingled with code and adding a static assertion within a compound statement block. - Fixed use of initialized stmt variable. Tested by using sparse on entire kernel tree and a similarly-sized code tree which makes use of _Static_assert(). v4: Addressed feedback, simplified and restructured to better model description in draft standard. v3: - Removed bogus test case introduced in v2 (static assertion on sizeof a structure within the definition of the structure). v2: - Added additional test cases. - Added additional validation for parameters to _Static_assert(). - Reworked implementation to avoid impacting struct/union definition handling ( the v1 implementation, which treated _Static_assert() as an NS_TYPEDEF term, had the unfortunate side-effect of leaving an unnamed field with unknown size attached to structure definitions when a static assert was inside a structure definition). ident-list.h | 1 + parse.c | 66 ++++++++++++++++++++++++++++++++++++++++------ validation/static_assert.c | 64 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 123 insertions(+), 8 deletions(-) create mode 100644 validation/static_assert.c diff --git a/ident-list.h b/ident-list.h index b65b667..4732ecc 100644 --- a/ident-list.h +++ b/ident-list.h @@ -16,6 +16,7 @@ IDENT_RESERVED(for); IDENT_RESERVED(while); IDENT_RESERVED(do); IDENT_RESERVED(goto); +IDENT_RESERVED(_Static_assert); /* C typenames. They get marked as reserved when initialized */ IDENT(struct); diff --git a/parse.c b/parse.c index b52c6ab..73fc5a3 100644 --- a/parse.c +++ b/parse.c @@ -73,6 +73,7 @@ static struct token *parse_context_statement(struct token *token, struct stateme static struct token *parse_range_statement(struct token *token, struct statement *stmt); static struct token *parse_asm_statement(struct token *token, struct statement *stmt); static struct token *toplevel_asm_declaration(struct token *token, struct symbol_list **list); +static struct token *parse_static_assert(struct token *token, struct symbol_list **unused); typedef struct token *attr_t(struct token *, struct symbol *, struct decl_state *); @@ -308,6 +309,10 @@ static struct symbol_op asm_op = { .toplevel = toplevel_asm_declaration, }; +static struct symbol_op static_assert_op = { + .toplevel = parse_static_assert, +}; + static struct symbol_op packed_op = { .attribute = attribute_packed, }; @@ -437,6 +442,9 @@ static struct init_keyword { { "__restrict", NS_TYPEDEF, .op = &restrict_op}, { "__restrict__", NS_TYPEDEF, .op = &restrict_op}, + /* Static assertion */ + { "_Static_assert", NS_KEYWORD, .op = &static_assert_op }, + /* Storage class */ { "auto", NS_TYPEDEF, .op = &auto_op }, { "register", NS_TYPEDEF, .op = ®ister_op }, @@ -660,6 +668,11 @@ static int SENTINEL_ATTR match_idents(struct token *token, ...) return next && token->ident == next; } +static int match_static_assert(struct token *token) +{ + return token_type(token) == TOKEN_IDENT && + token->ident == &_Static_assert_ident; +} struct statement *alloc_statement(struct position pos, int type) { @@ -1864,13 +1877,17 @@ static struct token *declaration_list(struct token *token, struct symbol_list ** static struct token *struct_declaration_list(struct token *token, struct symbol_list **list) { while (!match_op(token, '}')) { - if (!match_op(token, ';')) - token = declaration_list(token, list); - if (!match_op(token, ';')) { - sparse_error(token->pos, "expected ; at end of declaration"); - break; + if (match_static_assert(token)) + token = parse_static_assert(token, NULL); + else { + if (!match_op(token, ';')) + token = declaration_list(token, list); + if (!match_op(token, ';')) { + sparse_error(token->pos, "expected ; at end of declaration"); + break; + } + token = token->next; } - token = token->next; } return token; } @@ -2012,6 +2029,36 @@ static struct token *parse_asm_declarator(struct token *token, struct decl_state return token; } + +static struct token *parse_static_assert(struct token *token, struct symbol_list **unused) +{ + struct expression *expr1 = NULL, *expr2 = NULL; + int val; + + token = expect(token->next, '(', "after _Static_assert"); + token = constant_expression(token, &expr1); + token = expect(token, ',', "after first argument of _Static_assert"); + token = parse_expression(token, &expr2); + token = expect(token, ')', "after second argument of _Static_assert"); + + token = expect(token, ';', "after _Static_assert()"); + + if (!expr1 || !expr2) + return token; + + val = const_expression_value(expr1); + + if (expr2->type != EXPR_STRING) + sparse_error(expr2->pos, "bad string literal"); + else if (expr1 && (expr1->type == EXPR_VALUE)) { + if (!val) + sparse_error(expr1->pos, "static assertion failed: %s", + show_string(expr2->string)); + } + + return token; +} + /* Make a statement out of an expression */ static struct statement *make_statement(struct expression *expr) { @@ -2389,11 +2436,14 @@ static struct token * statement_list(struct token *token, struct statement_list } stmt = alloc_statement(token->pos, STMT_DECLARATION); token = external_declaration(token, &stmt->declaration); + add_statement(list, stmt); + } else if (match_static_assert(token)) { + token = parse_static_assert(token, NULL); } else { seen_statement = Wdeclarationafterstatement; token = statement(token, &stmt); + add_statement(list, stmt); } - add_statement(list, stmt); } return token; } @@ -2726,7 +2776,7 @@ struct token *external_declaration(struct token *token, struct symbol_list **lis unsigned long mod; int is_typedef; - /* Top-level inline asm? */ + /* Top-level inline asm or static assertion? */ if (token_type(token) == TOKEN_IDENT) { struct symbol *s = lookup_keyword(token->ident, NS_KEYWORD); if (s && s->op->toplevel) diff --git a/validation/static_assert.c b/validation/static_assert.c new file mode 100644 index 0000000..c7a5ec5 --- /dev/null +++ b/validation/static_assert.c @@ -0,0 +1,64 @@ +_Static_assert(1, "global ok"); + +struct foo { + _Static_assert(1, "struct ok"); +}; + +void bar(void) +{ + _Static_assert(1, " func1 ok"); + int i; + i = 0; + _Static_assert(1, " func2 ok"); + + if (1) { + _Static_assert(1, " func3 ok"); + } +} + +_Static_assert(0, "expected assertion failure"); + +static int f; +_Static_assert(f, "non-constant expression"); + +static int *p; +_Static_assert(p, "non-integer expression"); + +_Static_assert(0.1, "float expression"); + +_Static_assert(!0 == 1, "non-trivial expression"); + +static char array[4]; +_Static_assert(sizeof(array) == 4, "sizeof expression"); + +static const char non_literal_string[] = "non literal string"; +_Static_assert(0, non_literal_string); + +_Static_assert(1 / 0, "invalid expression: should not show up?"); + +struct s { + char arr[16]; + _Static_assert(1, "inside struct"); +}; + +union u { + char c; + int i; + _Static_assert(1, "inside union"); +}; + +_Static_assert(sizeof(struct s) == 16, "sizeof assertion"); + +/* + * check-name: static assertion + * + * check-error-start +static_assert.c:19:16: error: static assertion failed: "expected assertion failure" +static_assert.c:22:16: error: bad constant expression +static_assert.c:25:16: error: bad constant expression +static_assert.c:27:16: error: bad constant expression +static_assert.c:35:19: error: bad string literal +static_assert.c:37:18: error: bad constant expression + * check-error-end + */ +