From patchwork Mon Oct 29 15:39:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Dooks X-Patchwork-Id: 10659439 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AAAE417DF for ; Mon, 29 Oct 2018 15:39:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A61CC29AD3 for ; Mon, 29 Oct 2018 15:39:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9A5D829AD7; Mon, 29 Oct 2018 15:39:57 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 CFB7229AD3 for ; Mon, 29 Oct 2018 15:39:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727545AbeJ3A3E (ORCPT ); Mon, 29 Oct 2018 20:29:04 -0400 Received: from imap1.codethink.co.uk ([176.9.8.82]:59236 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727520AbeJ3A3D (ORCPT ); Mon, 29 Oct 2018 20:29:03 -0400 Received: from [148.252.241.226] (helo=rainbowdash) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1gH9dx-0005vP-Vb; Mon, 29 Oct 2018 15:39:54 +0000 Received: from ben by rainbowdash with local (Exim 4.91) (envelope-from ) id 1gH9dx-0003eY-LJ; Mon, 29 Oct 2018 15:39:53 +0000 From: Ben Dooks To: linux-sparse@vger.kernel.org Cc: Ben Dooks Subject: [PATCH 3/5] initial parsing of __attribute__((format)) Date: Mon, 29 Oct 2018 15:39:50 +0000 Message-Id: <20181029153952.13927-4-ben.dooks@codethink.co.uk> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181029153952.13927-1-ben.dooks@codethink.co.uk> References: <20181029153952.13927-1-ben.dooks@codethink.co.uk> MIME-Version: 1.0 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 Add code to parse the __attribute__((format)) used to indicate that a variadic function takes a printf-style format string and where those are. Save the data in ctype ready for checking when such an function is encoutered. Signed-off-by: Ben Dooks --- Fixes since v1: - moved to using ctype in base_type to store infromation - fixed formatting issues - updated check for bad format arguments - reduced the line count to unsigned short to save space Notes: - What to do when base_type is not set... current code doesn't work --- parse.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-- symbol.h | 2 ++ 2 files changed, 74 insertions(+), 2 deletions(-) diff --git a/parse.c b/parse.c index 02a55a7..9b0d40e 100644 --- a/parse.c +++ b/parse.c @@ -84,7 +84,7 @@ static attr_t attribute_address_space, attribute_context, attribute_designated_init, attribute_transparent_union, ignore_attribute, - attribute_mode, attribute_force; + attribute_mode, attribute_force, attribute_format; typedef struct symbol *to_mode_t(struct symbol *); @@ -353,6 +353,10 @@ static struct symbol_op attr_force_op = { .attribute = attribute_force, }; +static struct symbol_op attr_format = { + .attribute = attribute_format, +}; + static struct symbol_op address_space_op = { .attribute = attribute_address_space, }; @@ -407,6 +411,10 @@ static struct symbol_op mode_word_op = { .to_mode = to_word_mode }; +static struct symbol_op attr_printf_op = { + .type = KW_FORMAT, +}; + /* Using NS_TYPEDEF will also make the keyword a reserved one */ static struct init_keyword { const char *name; @@ -513,6 +521,8 @@ static struct init_keyword { { "bitwise", NS_KEYWORD, MOD_BITWISE, .op = &attr_bitwise_op }, { "__bitwise__",NS_KEYWORD, MOD_BITWISE, .op = &attr_bitwise_op }, { "address_space",NS_KEYWORD, .op = &address_space_op }, + { "format", NS_KEYWORD, .op = &attr_format }, + { "printf", NS_KEYWORD, .op = &attr_printf_op }, { "mode", NS_KEYWORD, .op = &mode_op }, { "context", NS_KEYWORD, .op = &context_op }, { "designated_init", NS_KEYWORD, .op = &designated_init_op }, @@ -1051,6 +1061,67 @@ static struct token *attribute_address_space(struct token *token, struct symbol return token; } +static struct token *attribute_format(struct token *token, struct symbol *attr, struct decl_state *ctx) +{ + struct expression *args[3]; + struct symbol *fmt_sym = NULL; + int argc = 0; + + /* expecting format ( type, start, va_args at) */ + + token = expect(token, '(', "after format attribute"); + while (!match_op(token, ')')) { + struct expression *expr = NULL; + + if (argc == 0) { + if (token_type(token) == TOKEN_IDENT) + fmt_sym = lookup_keyword(token->ident, NS_KEYWORD); + + if (!fmt_sym || !fmt_sym->op || + fmt_sym->op != &attr_printf_op) { + sparse_error(token->pos, + "unknown format type '%s'\n", + show_ident(token->ident)); + fmt_sym = NULL; + } + } + + token = conditional_expression(token, &expr); + if (!expr) + break; + if (argc < 3) + args[argc++] = expr; + if (!match_op(token, ',')) + break; + token = token->next; + } + + if (argc != 3 || !fmt_sym) { + warning(token->pos, "incorrect format attribute"); + } else { + long long start, at; + + start = get_expression_value(args[2]); + at = get_expression_value(args[1]); + + if (start <= 0 || at <= 0 || (start == at && start > 0)) { + warning(token->pos, "bad format positions"); + } else if (start < at) { + warning(token->pos, "format cannot be after va_args"); + } else if (!ctx->ctype.base_type) { + warning(token->pos, "no base type to set"); + ctx->ctype.printf_va_start = start; + ctx->ctype.printf_msg = at; + } else { + ctx->ctype.base_type->ctype.printf_va_start = start; + ctx->ctype.base_type->ctype.printf_msg = at; + } + } + + token = expect(token, ')', "after format attribute"); + return token; +} + static struct symbol *to_QI_mode(struct symbol *ctype) { if (ctype->ctype.base_type != &int_type) @@ -2102,7 +2173,6 @@ static struct statement *start_function(struct symbol *sym) // Currently parsed symbol for __func__/__FUNCTION__/__PRETTY_FUNCTION__ current_fn = sym; - return stmt; } diff --git a/symbol.h b/symbol.h index 1f338f5..4cd8d61 100644 --- a/symbol.h +++ b/symbol.h @@ -86,6 +86,7 @@ enum keyword { KW_SHORT = 1 << 7, KW_LONG = 1 << 8, KW_EXACT = 1 << 9, + KW_FORMAT = 1 << 10, }; struct context { @@ -103,6 +104,7 @@ struct ctype { struct context_list *contexts; unsigned int as; struct symbol *base_type; + unsigned short printf_va_start, printf_msg; }; struct decl_state {