Store and read name of alternatives

Add the names of supplied alternatives to the .PKGINFO file.  Read and store
these values in libalpm.  This information is currently not used anywhere.

Signed-off-by: Allan McRae <allan@archlinux.org>

doc/PKGBUILD.5.asciidoc

@@ -402,8 +402,8 @@ All options and directives for the split packages default to the global values
 given in the PKGBUILD. Nevertheless, the following ones can be overridden within
 each split package's packaging function:
 `pkgdesc`, `arch`, `url`, `license`, `groups`, `depends`, `optdepends`,
-`provides`, `conflicts`, `replaces`, `backup`, `options`, `install`, and
+`provides`, `conflicts`, `replaces`, `backup`, `options`, `install`,
-`changelog`.
+`changelog` and `alternative`.
 
 Note that makepkg does not consider split package `depends` when checking
 if dependencies are installed before package building and with `--syncdeps`.

lib/libalpm/alpm.h

@@ -2555,6 +2555,12 @@ alpm_filelist_t *alpm_pkg_get_files(alpm_pkg_t *pkg);
  */
 alpm_list_t *alpm_pkg_get_backup(alpm_pkg_t *pkg);
 
+/** Returns the list of alternatives provided by the package
+ * @param pkg a pointer to package
+ * @return a reference to a list of char* objects
+ */
+alpm_list_t *alpm_pkg_get_alternatives(alpm_pkg_t *pkg);
+
 /** Returns the database containing pkg.
  * Returns a pointer to the alpm_db_t structure the package is
  * originating from, or NULL if the package was loaded from a file.

lib/libalpm/be_local.c

@@ -195,6 +195,12 @@ static alpm_list_t *_cache_get_backup(alpm_pkg_t *pkg)
 	return pkg->backup;
 }
 
+static alpm_list_t *_cache_get_alternatives(alpm_pkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC);
+	return pkg->alternatives;
+}
+
 /**
  * Open a package changelog for reading. Similar to fopen in functionality,
  * except that the returned 'file stream' is from the database.
@@ -349,6 +355,7 @@ static const struct pkg_operations local_pkg_ops = {
 	.get_replaces = _cache_get_replaces,
 	.get_files = _cache_get_files,
 	.get_backup = _cache_get_backup,
+	.get_alternatives = _cache_get_alternatives,
 
 	.changelog_open = _cache_changelog_open,
 	.changelog_read = _cache_changelog_read,
@@ -804,6 +811,8 @@ static int local_db_read(alpm_pkg_t *info, int inforeq)
 				READ_AND_SPLITDEP(info->conflicts);
 			} else if(strcmp(line, "%PROVIDES%") == 0) {
 				READ_AND_SPLITDEP(info->provides);
+			} else if(strcmp(line, "%ALTERNATIVES%") == 0) {
+				READ_AND_STORE_ALL(info->alternatives);
 			}
 		}
 		fclose(fp);
@@ -1040,6 +1049,15 @@ int _alpm_local_db_write(alpm_db_t *db, alpm_pkg_t *info, int inforeq)
 		write_deps(fp, "%CONFLICTS%", info->conflicts);
 		write_deps(fp, "%PROVIDES%", info->provides);
 
+		if(info->alternatives) {
+			fputs("%ALTERNATIVES%\n", fp);
+			for(lp = info->alternatives; lp; lp = lp->next) {
+				fputs(lp->data, fp);
+				fputc('\n', fp);
+			}
+			fputc('\n', fp);
+		}
+
 		fclose(fp);
 		fp = NULL;
 	}

lib/libalpm/be_package.c

@@ -244,6 +244,8 @@ static int parse_descfile(alpm_handle_t *handle, struct archive *a, alpm_pkg_t *
 				CALLOC(backup, 1, sizeof(alpm_backup_t), return -1);
 				STRDUP(backup->name, ptr, FREE(backup); return -1);
 				newpkg->backup = alpm_list_add(newpkg->backup, backup);
+			} else if(strcmp(key, "alternative") == 0) {
+				newpkg->alternatives = alpm_list_add(newpkg->alternatives, strdup(ptr));
 			} else if(strcmp(key, "force") == 0) {
 				/* deprecated, skip it */
 			} else if(strcmp(key, "makepkgopt") == 0) {

lib/libalpm/package.c

@@ -98,6 +98,7 @@ static alpm_list_t *_pkg_get_provides(alpm_pkg_t *pkg)   { return pkg->provides;
 static alpm_list_t *_pkg_get_replaces(alpm_pkg_t *pkg)   { return pkg->replaces; }
 static alpm_filelist_t *_pkg_get_files(alpm_pkg_t *pkg)  { return &(pkg->files); }
 static alpm_list_t *_pkg_get_backup(alpm_pkg_t *pkg)     { return pkg->backup; }
+static alpm_list_t *_pkg_get_alternatives(alpm_pkg_t *pkg) { return pkg->alternatives; }
 
 static void *_pkg_changelog_open(alpm_pkg_t UNUSED *pkg)
 {
@@ -162,6 +163,7 @@ const struct pkg_operations default_pkg_ops = {
 	.get_replaces    = _pkg_get_replaces,
 	.get_files       = _pkg_get_files,
 	.get_backup      = _pkg_get_backup,
+	.get_alternatives = _pkg_get_alternatives,
 
 	.changelog_open  = _pkg_changelog_open,
 	.changelog_read  = _pkg_changelog_read,
@@ -418,6 +420,13 @@ alpm_list_t SYMEXPORT *alpm_pkg_get_backup(alpm_pkg_t *pkg)
 	return pkg->ops->get_backup(pkg);
 }
 
+alpm_list_t SYMEXPORT *alpm_pkg_get_alternatives(alpm_pkg_t *pkg)
+{
+	ASSERT(pkg != NULL, return NULL);
+	pkg->handle->pm_errno = ALPM_ERR_OK;
+	return pkg->ops->get_alternatives(pkg);
+}
+
 alpm_db_t SYMEXPORT *alpm_pkg_get_db(alpm_pkg_t *pkg)
 {
 	/* Sanity checks */
@@ -632,6 +641,7 @@ int _alpm_pkg_dup(alpm_pkg_t *pkg, alpm_pkg_t **new_ptr)
 	newpkg->optdepends = list_depdup(pkg->optdepends);
 	newpkg->conflicts  = list_depdup(pkg->conflicts);
 	newpkg->provides   = list_depdup(pkg->provides);
+	newpkg->alternatives = alpm_list_strdup(pkg->alternatives);
 
 	if(pkg->files.count) {
 		size_t filenum;
@@ -709,6 +719,7 @@ void _alpm_pkg_free(alpm_pkg_t *pkg)
 	free_deplist(pkg->provides);
 	alpm_list_free(pkg->removes);
 	_alpm_pkg_free(pkg->oldpkg);
+	FREELIST(pkg->alternatives);
 
 	if(pkg->origin == ALPM_PKG_FROM_FILE) {
 		FREE(pkg->origin_data.file);

lib/libalpm/package.h

@@ -66,6 +66,7 @@ struct pkg_operations {
 	alpm_list_t *(*get_replaces) (alpm_pkg_t *);
 	alpm_filelist_t *(*get_files) (alpm_pkg_t *);
 	alpm_list_t *(*get_backup) (alpm_pkg_t *);
+	alpm_list_t *(*get_alternatives) (alpm_pkg_t *);
 
 	void *(*changelog_open) (alpm_pkg_t *);
 	size_t (*changelog_read) (void *, size_t, const alpm_pkg_t *, void *);
@@ -120,6 +121,7 @@ struct _alpm_pkg_t {
 	alpm_list_t *provides;
 	alpm_list_t *removes; /* in transaction targets only */
 	alpm_pkg_t *oldpkg; /* in transaction targets only */
+	alpm_list_t *alternatives;
 
 	const struct pkg_operations *ops;
 

scripts/libmakepkg/lint_pkgbuild/alternative.sh.in

@@ -0,0 +1,41 @@
+#!/bin/bash
+#
+#   alternative.sh - Check the files associated with the 'alternative'
+#   array exist.
+#
+#   Copyright (c) 2020 Pacman Development Team <pacman-dev@archlinux.org>
+#
+#   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 2 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 <http://www.gnu.org/licenses/>.
+#
+
+[[ -n "$LIBMAKEPKG_LINT_PKGBUILD_ALTERNATIVE_SH" ]] && return
+LIBMAKEPKG_LINT_PKGBUILD_ALTERNATIVE_SH=1
+
+LIBRARY=${LIBRARY:-'@libmakepkgdir@'}
+
+source "$LIBRARY/util/message.sh"
+source "$LIBRARY/util/pkgbuild.sh"
+source "$LIBRARY/lint_pkgbuild/util.sh"
+
+
+lint_pkgbuild_functions+=('lint_alternative')
+
+
+lint_alternative() {
+	local ret=0
+
+	check_files_exist 'alternative' "${alternative[@]/%/.alternative}" || ret=1
+
+	return $ret
+}

scripts/libmakepkg/lint_pkgbuild/meson.build

@@ -1,6 +1,7 @@
 libmakepkg_module = 'lint_pkgbuild'
 
 sources = [
+  'alternative.sh.in',
   'arch.sh.in',
   'arch_specific.sh.in',
   'backup.sh.in',

scripts/libmakepkg/util/schema.sh.in

@@ -28,8 +28,8 @@ source "$LIBRARY/util/util.sh"
 
 known_hash_algos=({ck,md5,sha{1,224,256,384,512},b2})
 
-pkgbuild_schema_arrays=(arch backup checkdepends conflicts depends groups
+pkgbuild_schema_arrays=(alternative arch backup checkdepends conflicts depends
-                        license makedepends noextract optdepends options
+                        groups license makedepends noextract optdepends options
                         provides replaces source validpgpkeys
                         "${known_hash_algos[@]/%/sums}")
 
@@ -42,7 +42,7 @@ pkgbuild_schema_arch_arrays=(checkdepends conflicts depends makedepends
 
 pkgbuild_schema_package_overrides=(pkgdesc arch url license groups depends
                                    optdepends provides conflicts replaces
-                                   backup options install changelog)
+                                   backup options install changelog alternative)
 
 readonly -a known_hash_algos pkgbuild_schema_arrays \
 	pkgbuild_schema_strings pkgbuild_schema_arch_arrays \

scripts/makepkg.sh.in

@@ -630,6 +630,7 @@ write_pkginfo() {
 	write_kv_pair "optdepend"   "${optdepends[@]//+([[:space:]])/ }"
 	write_kv_pair "makedepend"  "${makedepends[@]}"
 	write_kv_pair "checkdepend" "${checkdepends[@]}"
+	write_kv_pair "alternative" "${alternative[@]}"
 }
 
 write_buildinfo() {
@@ -710,6 +711,16 @@ create_package() {
 		fi
 	done
 
+	# check for alternative files
+	for i in ${alternative[@]}; do
+		msg2 "$(gettext "Adding %s file...")" "$i.alternative"
+		if ! cp "$startdir/$i.alternative" ".ALTERNATIVE.$i"; then
+			error "$(gettext "Failed to add %s file to package.")" "$i.alternative"
+			exit $E_MISSING_FILE
+		fi
+		chmod 644 ".ALTERNATIVE.$i"
+	done
+
 	# tar it up
 	local fullver=$(get_full_version)
 	local pkg_file="$PKGDEST/${pkgname}-${fullver}-${pkgarch}${PKGEXT}"