diff options
Diffstat (limited to 'tools/gnulib/patches/689-vc-mtime.patch')
| -rw-r--r-- | tools/gnulib/patches/689-vc-mtime.patch | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/tools/gnulib/patches/689-vc-mtime.patch b/tools/gnulib/patches/689-vc-mtime.patch new file mode 100644 index 0000000000..62638d7ff4 --- /dev/null +++ b/tools/gnulib/patches/689-vc-mtime.patch @@ -0,0 +1,366 @@ +From 701d20aaf579bb71f35209dd63a272c3d9d21096 Mon Sep 17 00:00:00 2001 +From: Bruno Haible <bruno@clisp.org> +Date: Mon, 24 Feb 2025 19:03:17 +0100 +Subject: [PATCH] vc-mtime: New module. + +* lib/vc-mtime.h: New file. +* lib/vc-mtime.c: New file. +* modules/vc-mtime: New file. +--- + ChangeLog | 7 ++ + lib/vc-mtime.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++ + lib/vc-mtime.h | 97 ++++++++++++++++++++++ + modules/vc-mtime | 34 ++++++++ + 4 files changed, 346 insertions(+) + create mode 100644 lib/vc-mtime.c + create mode 100644 lib/vc-mtime.h + create mode 100644 modules/vc-mtime + +--- /dev/null ++++ b/lib/vc-mtime.c +@@ -0,0 +1,208 @@ ++/* Return the version-control based modification time of a file. ++ Copyright (C) 2025 Free Software Foundation, Inc. ++ ++ This program is free software: you can redistribute it and/or modify ++ it under the terms of the GNU General Public License as published by ++ the Free Software Foundation, either version 3 of the License, or ++ (at your option) any later version. ++ ++ This program is distributed in the hope that it will be useful, ++ but WITHOUT ANY WARRANTY; without even the implied warranty of ++ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ++ GNU General Public License for more details. ++ ++ You should have received a copy of the GNU General Public License ++ along with this program. If not, see <https://www.gnu.org/licenses/>. */ ++ ++/* Written by Bruno Haible <bruno@clisp.org>, 2025. */ ++ ++#include <config.h> ++ ++/* Specification. */ ++#include "vc-mtime.h" ++ ++#include <stdlib.h> ++#include <unistd.h> ++ ++#include <error.h> ++#include "spawn-pipe.h" ++#include "wait-process.h" ++#include "execute.h" ++#include "safe-read.h" ++#include "xstrtol.h" ++#include "stat-time.h" ++#include "gettext.h" ++ ++#define _(msgid) dgettext ("gnulib", msgid) ++ ++ ++/* Determines whether the specified file is under version control. */ ++static bool ++git_vc_controlled (const char *filename) ++{ ++ /* Run "git ls-files FILENAME" and return true if the exit code is 0 ++ and the output is non-empty. */ ++ const char *argv[4]; ++ pid_t child; ++ int fd[1]; ++ ++ argv[0] = "git"; ++ argv[1] = "ls-files"; ++ argv[2] = filename; ++ argv[3] = NULL; ++ child = create_pipe_in ("git", "git", argv, NULL, NULL, ++ DEV_NULL, true, true, false, fd); ++ if (child == -1) ++ return false; ++ ++ /* Read the subprocess output, and test whether it is non-empty. */ ++ size_t count = 0; ++ char c; ++ ++ while (safe_read (fd[0], &c, 1) > 0) ++ count++; ++ ++ close (fd[0]); ++ ++ /* Remove zombie process from process list, and retrieve exit status. */ ++ int exitstatus = ++ wait_subprocess (child, "git", false, true, true, false, NULL); ++ return (exitstatus == 0 && count > 0); ++} ++ ++/* Determines whether the specified file is unmodified, compared to the ++ last version in version control. */ ++static bool ++git_unmodified (const char *filename) ++{ ++ /* Run "git diff --quiet -- HEAD FILENAME" ++ (or "git diff --quiet HEAD FILENAME") ++ and return true if the exit code is 0. ++ The '--' option is for the case that the specified file was removed. */ ++ const char *argv[7]; ++ int exitstatus; ++ ++ argv[0] = "git"; ++ argv[1] = "diff"; ++ argv[2] = "--quiet"; ++ argv[3] = "--"; ++ argv[4] = "HEAD"; ++ argv[5] = filename; ++ argv[6] = NULL; ++ exitstatus = execute ("git", "git", argv, NULL, NULL, ++ false, false, true, true, ++ true, false, NULL); ++ return (exitstatus == 0); ++} ++ ++/* Stores in *MTIME the time of last modification in version control of the ++ specified file, and returns 0. ++ Upon failure, it returns -1. */ ++static int ++git_mtime (struct timespec *mtime, const char *filename) ++{ ++ /* Run "git log -1 --format=%ct -- FILENAME". It prints the time of last ++ modification, as the number of seconds since the Epoch. ++ The '--' option is for the case that the specified file was removed. */ ++ const char *argv[7]; ++ pid_t child; ++ int fd[1]; ++ ++ argv[0] = "git"; ++ argv[1] = "log"; ++ argv[2] = "-1"; ++ argv[3] = "--format=%ct"; ++ argv[4] = "--"; ++ argv[5] = filename; ++ argv[6] = NULL; ++ child = create_pipe_in ("git", "git", argv, NULL, NULL, ++ DEV_NULL, true, true, false, fd); ++ if (child == -1) ++ return -1; ++ ++ /* Retrieve its result. */ ++ FILE *fp; ++ char *line; ++ size_t linesize; ++ size_t linelen; ++ ++ fp = fdopen (fd[0], "r"); ++ if (fp == NULL) ++ error (EXIT_FAILURE, errno, _("fdopen() failed")); ++ ++ line = NULL; linesize = 0; ++ linelen = getline (&line, &linesize, fp); ++ if (linelen == (size_t)(-1)) ++ { ++ error (0, 0, _("%s subprocess I/O error"), "git"); ++ fclose (fp); ++ wait_subprocess (child, "git", true, false, true, false, NULL); ++ } ++ else ++ { ++ int exitstatus; ++ ++ if (linelen > 0 && line[linelen - 1] == '\n') ++ line[linelen - 1] = '\0'; ++ ++ fclose (fp); ++ ++ /* Remove zombie process from process list, and retrieve exit status. */ ++ exitstatus = ++ wait_subprocess (child, "git", true, false, true, false, NULL); ++ if (exitstatus == 0) ++ { ++ char *endptr; ++ unsigned long git_log_time; ++ if (xstrtoul (line, &endptr, 10, &git_log_time, NULL) == LONGINT_OK ++ && endptr == line + strlen (line)) ++ { ++ mtime->tv_sec = git_log_time; ++ mtime->tv_nsec = 0; ++ free (line); ++ return 0; ++ } ++ } ++ } ++ free (line); ++ return -1; ++} ++ ++int ++vc_mtime (struct timespec *mtime, const char *filename) ++{ ++ static bool git_tested; ++ static bool git_present; ++ ++ if (!git_tested) ++ { ++ /* Test for presence of git: ++ "git --version >/dev/null 2>/dev/null" */ ++ const char *argv[3]; ++ int exitstatus; ++ ++ argv[0] = "git"; ++ argv[1] = "--version"; ++ argv[2] = NULL; ++ exitstatus = execute ("git", "git", argv, NULL, NULL, ++ false, false, true, true, ++ true, false, NULL); ++ git_present = (exitstatus == 0); ++ git_tested = true; ++ } ++ ++ if (git_present ++ && git_vc_controlled (filename) ++ && git_unmodified (filename)) ++ { ++ if (git_mtime (mtime, filename) == 0) ++ return 0; ++ } ++ struct stat statbuf; ++ if (stat (filename, &statbuf) == 0) ++ { ++ *mtime = get_stat_mtime (&statbuf); ++ return 0; ++ } ++ return -1; ++} +--- /dev/null ++++ b/lib/vc-mtime.h +@@ -0,0 +1,97 @@ ++/* Return the version-control based modification time of a file. ++ Copyright (C) 2025 Free Software Foundation, Inc. ++ ++ This program is free software: you can redistribute it and/or modify ++ it under the terms of the GNU General Public License as published by ++ the Free Software Foundation, either version 3 of the License, or ++ (at your option) any later version. ++ ++ This program is distributed in the hope that it will be useful, ++ but WITHOUT ANY WARRANTY; without even the implied warranty of ++ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ++ GNU General Public License for more details. ++ ++ You should have received a copy of the GNU General Public License ++ along with this program. If not, see <https://www.gnu.org/licenses/>. */ ++ ++/* Written by Bruno Haible <bruno@clisp.org>, 2025. */ ++ ++#ifndef _VC_MTIME_H ++#define _VC_MTIME_H ++ ++/* Get struct timespec. */ ++#include <time.h> ++ ++/* The "version-controlled modification time" vc_mtime(F) of a file F ++ is defined as: ++ - If F is under version control and not modified locally: ++ the time of the last change of F in the version control system. ++ - Otherwise: The modification time of F on disk. ++ ++ For now, the only VCS supported by this module is git. (hg and svn are ++ hardly in use any more.) ++ ++ This has the properties that: ++ - Different users who have checked out the same git repo on different ++ machines, at different times, and not done local modifications, ++ get the same vc_mtime(F). ++ - If a user has modified F locally, the modification time of that file ++ counts. ++ - If that user then reverts the modification, they then again get the ++ same vc_mtime(F) as everyone else. ++ - Different users who have unpacked the same tarball (without .git ++ directory) on different machines, at different times, also get the same ++ vc_mtime(F) [but possibly a different one than when the .git directory ++ was present]. (Assuming a POSIX compliant file system.) ++ - When a user commits local modifications into git, this only increases ++ (not decreases) the vc_mtime(F). ++ ++ The purpose of the version-controlled modification time is to produce a ++ reproducible timestamp(Z) of a file Z that depends on files X1, ..., Xn, ++ in such a way that ++ - timestamp(Z) is reproducible, that is, different users on different ++ machines get the same value. ++ - timestamp(Z) is related to reality. It's not just a dummy, like what ++ is suggested in <https://reproducible-builds.org/docs/timestamps/>. ++ - One can arrange for timestamp(Z) to respect the modification time ++ relations of a build system. ++ ++ There are two uses of such a timestamp: ++ - It can be set as the modification time of file Z in a file system, or ++ - It can be embedded in Z, with the purpose of telling a user how old ++ the file Z is. For example, in PDF files or in generated documentation, ++ such a time is embedded in a special place. ++ ++ The simplest example is a file Z that depends on files X1, ..., Xn. ++ Generally one will define ++ timestamp(Z) = max (vc_mtime(X1), ..., vc_mtime(Xn)) ++ for an embedded timestamp, or ++ timestamp(Z) = max (vc_mtime(X1), ..., vc_mtime(Xn)) + 1 second ++ for a time stamp in a file system. The added second ++ 1. accounts for fractional seconds in mtime(X1), ..., mtime(Xn), ++ 2. allows for 'make' implementation that attempt to rebuild Z ++ if mtime(Z) == mtime(Xi). ++ ++ A more complicated example is when there are intermediate built files, not ++ under version control. For example, if the build process produces ++ X1, X2 -> Y1 ++ X3, X4 -> Y2 ++ Y1, Y2, X5 -> Z ++ where Y1 and Y2 are intermediate built files, you should ignore the ++ mtime(Y1), mtime(Y2), and consider only the vc_mtime(X1), ..., vc_mtime(X5). ++ */ ++ ++#ifdef __cplusplus ++extern "C" { ++#endif ++ ++/* Determines the version-controlled modification time of FILENAME, stores it ++ in *MTIME, and returns 0. ++ Upon failure, it returns -1. */ ++extern int vc_mtime (struct timespec *mtime, const char *filename); ++ ++#ifdef __cplusplus ++} ++#endif ++ ++#endif /* _VC_MTIME_H */ +--- /dev/null ++++ b/modules/vc-mtime +@@ -0,0 +1,34 @@ ++Description: ++Returns the version-control based modification time of a file. ++ ++Files: ++lib/vc-mtime.h ++lib/vc-mtime.c ++ ++Depends-on: ++time-h ++bool ++spawn-pipe ++wait-process ++execute ++safe-read ++error ++getline ++xstrtol ++stat-time ++gettext-h ++gnulib-i18n ++ ++configure.ac: ++ ++Makefile.am: ++lib_SOURCES += vc-mtime.c ++ ++Include: ++"vm-mtime.h" ++ ++License: ++GPL ++ ++Maintainer: ++Bruno Haible |