From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=2607:f8b0:4864:20::143; helo=mail-it1-x143.google.com; envelope-from=ard.biesheuvel@linaro.org; receiver=edk2-devel@lists.01.org Received: from mail-it1-x143.google.com (mail-it1-x143.google.com [IPv6:2607:f8b0:4864:20::143]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id A3B2C2119AC2C for ; Tue, 11 Dec 2018 14:55:42 -0800 (PST) Received: by mail-it1-x143.google.com with SMTP id h65so6786720ith.3 for ; Tue, 11 Dec 2018 14:55:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=FS75Nl+DR1ZNLd/qpUjMdHv60HeCEFdzCMvohSbq5zE=; b=LF9nsIMLdLxhRIHvsVejsAlY3E26ZeXBa6pMwzCPwu/xDBo3wxM33KK15BEfGaxWOJ Gbl+ZAn/zPf1L0aavwvcMt3B58vzi0DzxOS3QthX9wQmvy/QGuVa3WOWjf8XFRrwmz5x gBdTx4PllAvIUNA/k6a6u20fEHcAdB22bt/28= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=FS75Nl+DR1ZNLd/qpUjMdHv60HeCEFdzCMvohSbq5zE=; b=GzoqFpw7I8kVg7+MnaTBsTDY4JLcEFBg8RPKUqTdzO+4vOyI7yH30AFb9EpQ38kgY9 ZUW9LWnOEDCSWvMc84QkzRdcTMajq/Gc5E6CwJSulcc/xgwOVd2ynA53I7PshvLqpTVT XM16xYZjIzTzTEIdtf74/i9+T/So6NBHS3F9wdQks7bYM+UJltpOJlIr/wk/4MSVxLn9 O7KocpVMKmJlI+E9sPlnR/3F4cpEFO0UQr3Cr7pVmwTbZZ5yj9lGkgQMw7rhSNFtp1gH tGPHwXNuTV2pxvuYfn/arycWaCtvwgGcn1mLWLtmXB7DagL/CIRuD9ZU5EASiDC+hD6I FT4g== X-Gm-Message-State: AA+aEWZLjmnjCH8+qC2oUo4yPOKvukD+K8pxGvmTeOnzZ4eoRIs/p/BW 9iB6GzEbvu4HMMmVOGiq3VdyUgjDhF1KR7eMTe14JQ== X-Google-Smtp-Source: AFSGD/XelFNyFsOqGk51JYNFoUzARpzXlJ2aPl6WaCEoBUtsjRBX4AXf6o+141U817JEzgjCgIRQgCJg6TQ7Ia0oO0g= X-Received: by 2002:a05:660c:4b:: with SMTP id p11mr4087505itk.71.1544568941666; Tue, 11 Dec 2018 14:55:41 -0800 (PST) MIME-Version: 1.0 References: <20181130224537.18936-1-ard.biesheuvel@linaro.org> <20181130224537.18936-7-ard.biesheuvel@linaro.org> <4a244c8f-8f59-2936-f543-2bd43f78af9c@redhat.com> <11e96d9d-7f7c-7b2d-c05d-e5d009a2f4b1@redhat.com> In-Reply-To: From: Ard Biesheuvel Date: Tue, 11 Dec 2018 23:55:29 +0100 Message-ID: To: "David F." Cc: Laszlo Ersek , "edk2-devel@lists.01.org" , "Carsey, Jaben" , "Gao, Liming" Subject: Re: [PATCH v2 6/6] BaseTools/CommonLib: drop definition of MAX_UINTN X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Dec 2018 22:55:42 -0000 Content-Type: text/plain; charset="UTF-8" On Tue, 11 Dec 2018 at 23:53, David F. wrote: > > I don't know, to me it's very clear that UINTN is talking about the target, just like size_t would be. > But which target? This change is against the source of the BaseTools, which are host tools that can be used to build a single target image consisting of 32-bit and 64-bit modules. So which size is the native size in this case? > There are/were a bunch of API's using UINTN so using UINTN was desirable, and where needed UINTN_MAX. > > I just don't see an advantage to removing it. Do see disadvantage to removing it for breaking existing code and for those that want the "native" (best/fasted/most efficient) int size for the processor (similar again to size_t) > > On Tue, Dec 11, 2018 at 7:46 AM Laszlo Ersek wrote: >> >> On 12/11/18 08:11, David F. wrote: >> > Not sure why you'd take that out when someone using UINTN for variables may >> > want to use MAX_UINTN ? Future may be different. >> >> The UINTN type comes from the UEFI spec: >> >> Unsigned value of native width. (4 bytes on supported 32-bit >> processor instructions, 8 bytes on supported 64-bit processor >> instructions, 16 bytes on supported 128-bit processor instructions) >> >> In this sense, "native" refers to the firmware execution environment. >> The firmware execution environment need not have anything in common with >> the build environment. (You can build 32-bit ARM firmware on X64 hosts.) >> In such a scenario, using UINTN *at all* is fraught with >> misunderstandings. It *would* be possible to use UINTN as it applies to >> the build (= hosted) environment, and in that sense MAX_UINTN would also >> be possible to define. However, the code being removed (= defining >> MAX_UINTN as MAX_ADDRESS) proves that that approach would be very easy >> to misunderstand and misuse. People could easily mistake it for applying >> to the firmware execution environment. >> >> UINT32 and UINT64 are not affected by this ambiguity. >> >> Optimally, given that the build utilities target a hosted C runtime, >> they should use standard C types, such as "unsigned int", or e.g. >> "uint32_t". Together with standard C macros expressing limits, such as >> UINT_MAX (from ) and UINT32_MAX (from ). >> >> Clearly no-one has capacity to clean up BaseTools like this. For >> starters, we should at least remove whatever actively causes confusion. >> >> Thanks, >> Laszlo >> >> > On Mon, Dec 3, 2018 at 5:08 AM Laszlo Ersek wrote: >> > >> >> On 11/30/18 23:45, Ard Biesheuvel wrote: >> >>> The maximum value that can be represented by the native word size >> >>> of the *target* should be irrelevant when compiling tools that >> >>> run on the build *host*. So drop the definition of MAX_UINTN, now >> >>> that we no longer use it. >> >>> >> >>> Contributed-under: TianoCore Contribution Agreement 1.1 >> >>> Signed-off-by: Ard Biesheuvel >> >>> Reviewed-by: Jaben Carsey >> >>> --- >> >>> BaseTools/Source/C/Common/CommonLib.h | 1 - >> >>> 1 file changed, 1 deletion(-) >> >>> >> >>> diff --git a/BaseTools/Source/C/Common/CommonLib.h >> >> b/BaseTools/Source/C/Common/CommonLib.h >> >>> index 6930d9227b87..b1c6c00a3478 100644 >> >>> --- a/BaseTools/Source/C/Common/CommonLib.h >> >>> +++ b/BaseTools/Source/C/Common/CommonLib.h >> >>> @@ -22,7 +22,6 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, >> >> EITHER EXPRESS OR IMPLIED. >> >>> >> >>> #define MAX_LONG_FILE_PATH 500 >> >>> >> >>> -#define MAX_UINTN MAX_ADDRESS >> >>> #define MAX_UINT64 ((UINT64)0xFFFFFFFFFFFFFFFFULL) >> >>> #define MAX_UINT16 ((UINT16)0xFFFF) >> >>> #define MAX_UINT8 ((UINT8)0xFF) >> >>> >> >> >> >> Reviewed-by: Laszlo Ersek >> >> _______________________________________________ >> >> edk2-devel mailing list >> >> edk2-devel@lists.01.org >> >> https://lists.01.org/mailman/listinfo/edk2-devel >> >> >> > >>