Merge pull request #363 from SoapGentoo/pcfiledir_symlink

`${pcfiledir}` symlink resolving

.gitignore

@@ -73,6 +73,7 @@ core
 /tests/provides
 /tests/regress
 /tests/requires
+/tests/symlink
 /tests/sysroot
 /tests/test_env.sh
 /tests/version

Makefile.am

@@ -107,6 +107,7 @@ EXTRA_DIST =	pkg.m4 \
 		tests/lib1/tuple-quoting.pc \
 		tests/lib1/empty-tuple.pc \
 		tests/lib1/orphaned-requires-private.pc \
+		tests/lib1/pcfiledir.pc \
 		tests/lib1/sysroot-dir-2.pc \
 		tests/lib1/sysroot-dir-3.pc \
 		tests/lib1/sysroot-dir-4.pc \
@@ -137,6 +138,7 @@ test_scripts=	tests/meson.build \
 		tests/provides.sh \
 		tests/regress.sh \
 		tests/requires.sh \
+		tests/symlink.sh \
 		tests/sysroot.sh \
 		tests/version.sh
 

libpkgconf/pkg.c

@@ -17,6 +17,15 @@
 #include <libpkgconf/stdinc.h>
 #include <libpkgconf/libpkgconf.h>
 
+#ifndef _WIN32
+#include <fcntl.h>    // open
+#include <libgen.h>   // basename/dirname
+#include <sys/stat.h> // lstat, S_ISLNK
+#include <unistd.h>   // close, readlinkat
+
+#include <string.h>
+#endif
+
 /*
  * !doc
  *
@@ -63,6 +72,65 @@ pkg_get_parent_dir(pkgconf_pkg_t *pkg)
 	char buf[PKGCONF_ITEM_SIZE], *pathbuf;
 
 	pkgconf_strlcpy(buf, pkg->filename, sizeof buf);
+#ifndef _WIN32
+	/*
+	 * We want to resolve symlinks, since ${pcfiledir} should point to the
+	 * parent of the file symlinked to.
+	 */
+	struct stat path_stat;
+	while (!lstat(buf, &path_stat) && S_ISLNK(path_stat.st_mode))
+	{
+		/*
+		 * Have to split the path into the dir + file components,
+		 * in order to extract the directory file descriptor.
+		 *
+		 * The nomenclature here uses the
+		 *
+		 *   ln <source> <target>
+		 *
+		 * model.
+		 */
+		char basenamebuf[PKGCONF_ITEM_SIZE];
+		pkgconf_strlcpy(basenamebuf, buf, sizeof(basenamebuf));
+		const char* targetfilename = basename(basenamebuf);
+
+		char dirnamebuf[PKGCONF_ITEM_SIZE];
+		pkgconf_strlcpy(dirnamebuf, buf, sizeof(dirnamebuf));
+		const char* targetdir = dirname(dirnamebuf);
+
+		const int dirfd = open(targetdir, O_DIRECTORY);
+		if (dirfd == -1)
+			break;
+
+		char sourcebuf[PKGCONF_ITEM_SIZE];
+		ssize_t len = readlinkat(dirfd, targetfilename, sourcebuf, sizeof(sourcebuf) - 1);
+		close(dirfd);
+
+		if (len == -1)
+			break;
+		sourcebuf[len] = '\0';
+
+		memset(buf, '\0', sizeof buf);
+		/*
+		 * The logic here can be a bit tricky, so here's a table:
+		 *
+		 *        <source>      |        <target>        |         result
+		 * -----------------------------------------------------------------------
+		 *     /bar (absolute)  |   foo/link (relative)  |         /bar (absolute)
+		 *   ../bar (relative)  |   foo/link (relative)  |   foo/../bar (relative)
+		 *     /bar (absolute)  |  /foo/link (absolute)  |         /bar (absolute)
+		 *   ../bar (relative)  |  /foo/link (absolute)  |  /foo/../bar (relative)
+		 */
+		if ((sourcebuf[0] != '/')        /* absolute path in <source> wins */
+		    && (strcmp(targetdir, "."))) /* do not prepend "." */
+		{
+			pkgconf_strlcat(buf, targetdir, sizeof buf);
+			pkgconf_strlcat(buf, "/", sizeof buf);
+		}
+		pkgconf_strlcat(buf, sourcebuf, sizeof buf);
+	}
+#endif
+
 	pathbuf = strrchr(buf, PKG_DIR_SEP_S);
 	if (pathbuf == NULL)
 		pathbuf = strrchr(buf, '/');

tests/Kyuafile.in

@@ -11,3 +11,4 @@ atf_test_program{name='conflicts'}
 atf_test_program{name='version'}
 atf_test_program{name='framework'}
 atf_test_program{name='provides'}
+atf_test_program{name='symlink'}

tests/lib1/pcfiledir.pc

@@ -0,0 +1,8 @@
+prefix=${pcfiledir}
+exec_prefix=${prefix}
+libdir=${prefix}/lib
+includedir=${prefix}/include
+
+Name: foo
+Description: A testing pkg-config file with a ${pcfiledir}
+Version: 1.2.3

tests/meson.build

@@ -11,8 +11,9 @@ tests = [
   'provides',
   'regress',
   'requires',
+  'symlink',
   'sysroot',
-  'version'
+  'version',
 ]
 
 

tests/symlink.sh

@@ -0,0 +1,122 @@
+#!/usr/bin/env atf-sh
+
+. $(atf_get_srcdir)/test_env.sh
+
+tests_init \
+	pcfiledir_symlink_absolute \
+	pcfiledir_symlink_relative
+
+# - We need to create a temporary subtree, since symlinks are not preserved
+#   in "make dist".
+# - ${srcdir} is relative and since we need to compare paths, we would have
+#   to portably canonicalize it again, which is hard. Instead, just keep
+#   the whole thing nested.
+pcfiledir_symlink_absolute_body()
+{
+	mkdir -p tmp/child
+	cp -f "${selfdir}/lib1/pcfiledir.pc" tmp/child/
+	ln -f -s "${PWD}/tmp/child/pcfiledir.pc" tmp/pcfiledir.pc  # absolute
+	ln -f -s tmp/pcfiledir.pc pcfiledir.pc
+
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir.pc
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix tmp/pcfiledir.pc
+	atf_check \
+		-o inline:"tmp/child\n" \
+		pkgconf --variable=prefix tmp/child/pcfiledir.pc
+
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix "${PWD}/pcfiledir.pc"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix "${PWD}/tmp/pcfiledir.pc"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix "${PWD}/tmp/child/pcfiledir.pc"
+
+	export PKG_CONFIG_PATH="."
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+	export PKG_CONFIG_PATH="${PWD}"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+
+	export PKG_CONFIG_PATH="tmp"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+	export PKG_CONFIG_PATH="${PWD}/tmp"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+
+	export PKG_CONFIG_PATH="tmp/child"
+	atf_check \
+		-o inline:"tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+	export PKG_CONFIG_PATH="${PWD}/tmp/child"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+}
+
+pcfiledir_symlink_relative_body()
+{
+	mkdir -p tmp/child
+	cp -f "${selfdir}/lib1/pcfiledir.pc" tmp/child/
+	ln -f -s child/pcfiledir.pc tmp/pcfiledir.pc  # relative
+	ln -f -s tmp/pcfiledir.pc pcfiledir.pc
+
+	atf_check \
+		-o inline:"tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir.pc
+	atf_check \
+		-o inline:"tmp/child\n" \
+		pkgconf --variable=prefix tmp/pcfiledir.pc
+	atf_check \
+		-o inline:"tmp/child\n" \
+		pkgconf --variable=prefix tmp/child/pcfiledir.pc
+
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix "${PWD}/pcfiledir.pc"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix "${PWD}/tmp/pcfiledir.pc"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix "${PWD}/tmp/child/pcfiledir.pc"
+
+	export PKG_CONFIG_PATH="."
+	atf_check \
+		-o inline:"tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+	export PKG_CONFIG_PATH="${PWD}"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+
+	export PKG_CONFIG_PATH="tmp"
+	atf_check \
+		-o inline:"tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+	export PKG_CONFIG_PATH="${PWD}/tmp"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+
+	export PKG_CONFIG_PATH="tmp/child"
+	atf_check \
+		-o inline:"tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+	export PKG_CONFIG_PATH="${PWD}/tmp/child"
+	atf_check \
+		-o inline:"${PWD}/tmp/child\n" \
+		pkgconf --variable=prefix pcfiledir
+}