From patchwork Wed Jan 18 10:44:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Pan2 via Gcc-patches" X-Patchwork-Id: 63334 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 591DA3858430 for ; Wed, 18 Jan 2023 10:44:55 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 591DA3858430 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1674038695; bh=iRghN7P+HFjrBEHjWpgfUCBGRMsVaL2KqCDVR2Ohy4c=; h=Date:To:Subject:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=q6roObgAvPE2fyASdfZ2Yi998Fn8JqVVl71nQ0DhCJdP/NMUgiDGQ/meOcN1bSnnk bBVYq3NKyJVFyq+XfQCzLYpM/Uw432NWyfY5k4+IhNyJysLBvtBdY/x/X0Wcrg/fOW Ptg75OV9TXMtT3EIV9tpVP88JtF3mzHjzKPgfncQ= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from confino.investici.org (confino.investici.org [93.190.126.19]) by sourceware.org (Postfix) with ESMTPS id 549933858D28 for ; Wed, 18 Jan 2023 10:44:22 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 549933858D28 Received: from 1.mail-backend.investici.org (unknown [10.0.0.11]) by confino.investici.org (Postfix) with ESMTP id 4Nxj781C7Lz10yL for ; Wed, 18 Jan 2023 10:44:20 +0000 (UTC) Received: from 1.webmail.investici.org (localhost [127.0.0.1]) (Authenticated sender: i.nixman@autistici.org) by 1.mail-backend.investici.org (Postfix) with ESMTPA id 4Nxj7774Q9z5wst for ; Wed, 18 Jan 2023 10:44:19 +0000 (UTC) MIME-Version: 1.0 Date: Wed, 18 Jan 2023 10:44:19 +0000 To: Gcc Patches Subject: realpath() patch to fix symlinks resolution for win32 User-Agent: Roundcube Webmail Message-ID: <7c061f6c1c090362efbbcb9af9f6c758@autistici.org> X-Sender: i.nixman@autistici.org X-Spam-Status: No, score=-8.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_NUMSUBJECT, KAM_SHORT, SPF_HELO_PASS, 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 X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: "i.nixman--- via Gcc-patches" From: "Li, Pan2 via Gcc-patches" Reply-To: i.nixman@autistici.org Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" hello again! the final version of the path for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108350 successfully bootstraped for x86_64-mingw32 and x86_64-linux. could anyone apply it please? best! diff --git a/libiberty/lrealpath.c b/libiberty/lrealpath.c index 3c7053b0b70..a1ad074d00e 100644 --- a/libiberty/lrealpath.c +++ b/libiberty/lrealpath.c @@ -68,8 +68,135 @@ extern char *canonicalize_file_name (const char *); /* cygwin has realpath, so it won't get here. */ # if defined (_WIN32) # define WIN32_LEAN_AND_MEAN -# include /* for GetFullPathName */ -# endif +# include /* for GetFullPathName/GetFinalPathNameByHandle/ + CreateFile/CloseHandle */ +# define WIN32_REPLACE_SLASHES(_ptr, _len) \ + for (unsigned i = 0; i != (_len); ++i) \ + if ((_ptr)[i] == '\\') (_ptr)[i] = '/'; + +# define WIN32_UNC_PREFIX "//?/UNC/" +# define WIN32_UNC_PREFIX_LEN (sizeof(WIN32_UNC_PREFIX)-1) +# define WIN32_IS_UNC_PREFIX(ptr) \ + (0 == memcmp(ptr, WIN32_UNC_PREFIX, WIN32_UNC_PREFIX_LEN)) + +# define WIN32_NON_UNC_PREFIX "//?/" +# define WIN32_NON_UNC_PREFIX_LEN (sizeof(WIN32_NON_UNC_PREFIX)-1) +# define WIN32_IS_NON_UNC_PREFIX(ptr) \ + (0 == memcmp(ptr, WIN32_NON_UNC_PREFIX, WIN32_NON_UNC_PREFIX_LEN)) + +/* Get full path name without symlinks resolution. + It also converts all forward slashes to back slashes. +*/ +char* get_full_path_name(const char *filename) { + DWORD len; + char *buf, *ptr, *res; + + /* determining the required buffer size. + from the man: `If the lpBuffer buffer is too small to contain + the path, the return value is the size, in TCHARs, of the buffer + that is required to hold the path _and_the_terminating_null_character_` + */ + len = GetFullPathName(filename, 0, NULL, NULL); + + if ( len == 0 ) + return strdup(filename); + + buf = (char *)malloc(len); + + /* no point to check the result again */ + len = GetFullPathName(filename, len, buf, NULL); + buf[len] = 0; + + /* replace slashes */ + WIN32_REPLACE_SLASHES(buf, len); + + /* calculate offset based on prefix type */ + len = WIN32_IS_UNC_PREFIX(buf) + ? (WIN32_UNC_PREFIX_LEN - 2) + : WIN32_IS_NON_UNC_PREFIX(buf) + ? WIN32_NON_UNC_PREFIX_LEN + : 0 + ; + + ptr = buf + len; + if ( WIN32_IS_UNC_PREFIX(buf) ) { + ptr[0] = '/'; + ptr[1] = '/'; + } + + res = strdup(ptr); + + free(buf); + + return res; +} + +# if _WIN32_WINNT >= 0x0600 + +/* Get full path name WITH symlinks resolution. + It also converts all forward slashes to back slashes. +*/ +char* get_final_path_name(HANDLE fh) { + DWORD len; + char *buf, *ptr, *res; + + /* determining the required buffer size. + from the man: `If the function fails because lpszFilePath is too + small to hold the string plus the terminating null character, + the return value is the required buffer size, in TCHARs. This + value _includes_the_size_of_the_terminating_null_character_`. + but in my testcase I have path with 26 chars, the function + returns 26 also, ie without the trailing zero-char... + */ + len = GetFinalPathNameByHandle( + fh + ,NULL + ,0 + ,FILE_NAME_NORMALIZED | VOLUME_NAME_DOS + ); + + if ( len == 0 ) + return NULL; + + len += 1; /* for zero-char */ + buf = (char *)malloc(len); + + /* no point to check the result again */ + len = GetFinalPathNameByHandle( + fh + ,buf + ,len + ,FILE_NAME_NORMALIZED | VOLUME_NAME_DOS + ); + buf[len] = 0; + + /* replace slashes */ + WIN32_REPLACE_SLASHES(buf, len); + + /* calculate offset based on prefix type */ + len = WIN32_IS_UNC_PREFIX(buf) + ? (WIN32_UNC_PREFIX_LEN - 2) + : WIN32_IS_NON_UNC_PREFIX(buf) + ? WIN32_NON_UNC_PREFIX_LEN + : 0 + ; + + ptr = buf + len; + if ( WIN32_IS_UNC_PREFIX(buf) ) { + ptr[0] = '/'; + ptr[1] = '/'; + } + + res = strdup(ptr); + + free(buf); + + return res; +} + +# endif // _WIN32_WINNT >= 0x0600 + +# endif // _WIN32 #endif char * @@ -128,30 +255,52 @@ lrealpath (const char *filename) } #endif - /* The MS Windows method. If we don't have realpath, we assume we - don't have symlinks and just canonicalize to a Windows absolute - path. GetFullPath converts ../ and ./ in relative paths to - absolute paths, filling in current drive if one is not given - or using the current directory of a specified drive (eg, "E:foo"). - It also converts all forward slashes to back slashes. */ + /* The MS Windows method */ #if defined (_WIN32) { - char buf[MAX_PATH]; - char* basename; - DWORD len = GetFullPathName (filename, MAX_PATH, buf, &basename); - if (len == 0 || len > MAX_PATH - 1) - return strdup (filename); - else - { - /* The file system is case-preserving but case-insensitive, - Canonicalize to lowercase, using the codepage associated - with the process locale. */ - CharLowerBuff (buf, len); - return strdup (buf); - } - } -#endif + char *res; + + /* For Windows Vista and greater */ +#if _WIN32_WINNT >= 0x0600 + + /* For some reason the function receives just empty `filename`, but not NULL. + What should we do in that case? + According to `strdup()` implementation + (https://elixir.bootlin.com/glibc/latest/source/string/strdup.c) + it will alloc 1 byte even for empty but non NULL string. + OK, will use `strdup()` for that case. + */ + if ( 0 == strlen(filename) ) + return strdup(filename); + + HANDLE fh = CreateFile( + filename + ,FILE_READ_ATTRIBUTES + ,FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE + ,NULL + ,OPEN_EXISTING + ,FILE_FLAG_BACKUP_SEMANTICS + ,NULL + ); + + if ( fh == INVALID_HANDLE_VALUE ) { + res = get_full_path_name(filename); + } else { + res = get_final_path_name(fh); + CloseHandle(fh); - /* This system is a lost cause, just duplicate the filename. */ - return strdup (filename); + if ( !res ) + res = get_full_path_name(filename); + } + +#else + + /* For Windows XP */ + res = get_full_path_name(filename); + +#endif // _WIN32_WINNT >= 0x0600 + + return res; + } +#endif // _WIN32 }