add support for making paths relocatable (closes #103)

Makefile.am

@@ -14,6 +14,7 @@ bin_PROGRAMS = pkgconf
 lib_LTLIBRARIES = libpkgconf.la
 
 EXTRA_DIST =	pkg.m4 \
+		tests/lib-relocatable/lib/pkgconfig/foo.pc \
 		tests/lib1/argv-parse-2.pc \
 		tests/lib1/dos-lineendings.pc \
 		tests/lib1/paren-quoting.pc \

libpkgconf/libpkgconf.h

@@ -184,6 +184,7 @@ void pkgconf_client_set_prefix_varname(pkgconf_client_t *client, const char *pre
 #define PKGCONF_PKG_PKGF_SKIP_ERRORS			0x080
 #define PKGCONF_PKG_PKGF_ITER_PKG_IS_PRIVATE		0x100
 #define PKGCONF_PKG_PKGF_SKIP_PROVIDES			0x200
+#define PKGCONF_PKG_PKGF_REDEFINE_PREFIX		0x400
 
 #define PKGCONF_PKG_ERRF_OK			0x0
 #define PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND	0x1

libpkgconf/pkg.c

@@ -181,6 +181,44 @@ pkgconf_pkg_parser_keyword_set(const pkgconf_client_t *client, pkgconf_pkg_t *pk
 	return true;
 }
 
+static const char *
+determine_prefix(const pkgconf_pkg_t *pkg)
+{
+	static char buf[PKGCONF_BUFSIZE];
+	char *pathiter;
+
+	pkgconf_strlcpy(buf, pkg->filename, sizeof buf);
+	pkgconf_path_relocate(buf, sizeof buf);
+
+	pathiter = strrchr(buf, PKG_DIR_SEP_S);
+	if (pathiter == NULL)
+		pathiter = strrchr(buf, '/');
+	if (pathiter != NULL)
+		pathiter[0] = '\0';
+
+	pathiter = strrchr(buf, PKG_DIR_SEP_S);
+	if (pathiter == NULL)
+		pathiter = strrchr(buf, '/');
+	if (pathiter == NULL)
+		return NULL;
+
+	/* parent dir is not pkgconfig, can't relocate then */
+	if (strcmp(pathiter + 1, "pkgconfig"))
+		return NULL;
+
+	/* okay, work backwards and do it again. */
+	pathiter[0] = '\0';
+	pathiter = strrchr(buf, PKG_DIR_SEP_S);
+	if (pathiter == NULL)
+		pathiter = strrchr(buf, '/');
+	if (pathiter == NULL)
+		return NULL;
+
+	pathiter[0] = '\0';
+
+	return buf;
+}
+
 /*
  * !doc
  *
@@ -249,7 +287,19 @@ pkgconf_pkg_new_from_file(const pkgconf_client_t *client, const char *filename,
 			pkgconf_pkg_parser_keyword_set(client, pkg, key, value);
 			break;
 		case '=':
+			if (strcmp(key, client->prefix_varname) || !(client->flags & PKGCONF_PKG_PKGF_REDEFINE_PREFIX))
 				pkgconf_tuple_add(client, &pkg->vars, key, value, true);
+			else
+			{
+				const char *relvalue = determine_prefix(pkg);
+				if (relvalue != NULL)
+				{
+					pkgconf_tuple_add(client, &pkg->vars, "orig_prefix", value, true);
+					pkgconf_tuple_add(client, &pkg->vars, key, relvalue, false);
+				}
+				else
+					pkgconf_tuple_add(client, &pkg->vars, key, value, true);
+			}
 			break;
 		default:
 			break;

main.c

@@ -52,6 +52,7 @@
 #define PKG_NO_PROVIDES			(((uint64_t) 1) << 32)
 #define PKG_PURE			(((uint64_t) 1) << 33)
 #define PKG_PATH			(((uint64_t) 1) << 34)
+#define PKG_DEFINE_PREFIX		(((uint64_t) 1) << 35)
 
 static pkgconf_client_t pkg_client;
 
@@ -569,8 +570,11 @@ usage(void)
 	printf("                                    walking the dependency graph\n");
 	printf("  --log-file=filename               write an audit log to a specified file\n");
 	printf("  --with-path=path                  adds a directory to the search path\n");
+	printf("  --define-prefix                   override the prefix variable with one that is guessed based on\n");
+	printf("                                    the location of the .pc file\n");
 	printf("  --prefix-variable=varname         sets the name of the variable that pkgconf considers\n");
 	printf("                                    to be the package prefix\n");
+	printf("  --relocate=path                   relocates a path and exits (mostly for testsuite)\n");
 
 	printf("\nchecking specific pkg-config database entries:\n\n");
 
@@ -614,6 +618,17 @@ usage(void)
 	printf("\nreport bugs to <%s>.\n", PACKAGE_BUGREPORT);
 }
 
+static void
+relocate_path(const char *path)
+{
+	char buf[PKGCONF_BUFSIZE];
+
+	pkgconf_strlcpy(buf, path, sizeof buf);
+	pkgconf_path_relocate(buf, sizeof buf);
+
+	printf("%s\n", buf);
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -678,6 +693,8 @@ main(int argc, char *argv[])
 		{ "path", no_argument, &want_flags, PKG_PATH },
 		{ "with-path", required_argument, NULL, 42 },
 		{ "prefix-variable", required_argument, NULL, 43 },
+		{ "define-prefix", no_argument, &want_flags, PKG_DEFINE_PREFIX },
+		{ "relocate", required_argument, NULL, 45 },
 		{ NULL, 0, NULL, 0 }
 	};
 
@@ -717,6 +734,9 @@ main(int argc, char *argv[])
 		case 43:
 			pkgconf_client_set_prefix_varname(&pkg_client, pkg_optarg);
 			break;
+		case 45:
+			relocate_path(pkg_optarg);
+			return EXIT_SUCCESS;
 		case '?':
 		case ':':
 			return EXIT_FAILURE;
@@ -787,6 +807,9 @@ main(int argc, char *argv[])
 	if ((want_flags & PKG_NO_CACHE) == PKG_NO_CACHE)
 		want_client_flags |= PKGCONF_PKG_PKGF_NO_CACHE;
 
+	if ((want_flags & PKG_DEFINE_PREFIX) == PKG_DEFINE_PREFIX)
+		want_client_flags |= PKGCONF_PKG_PKGF_REDEFINE_PREFIX;
+
 	if ((want_flags & PKG_NO_UNINSTALLED) == PKG_NO_UNINSTALLED || getenv("PKG_CONFIG_DISABLE_UNINSTALLED") != NULL)
 		want_client_flags |= PKGCONF_PKG_PKGF_NO_UNINSTALLED;
 

tests/basic.sh

@@ -33,7 +33,8 @@ tests_init \
 	nolibs \
 	nocflags \
 	arbitary_path \
-	with_path
+	with_path \
+	relocatable
 
 noargs_body()
 {
@@ -289,3 +290,11 @@ arbitary_path_body()
 		-o inline:"-L/test/lib -lfoo  \n" \
 		pkgconf --libs foo.pc
 }
+
+relocatable_body()
+{
+	basedir=$(pkgconf --relocate ${selfdir})
+	atf_check \
+		-o inline:"${basedir}/lib-relocatable\n" \
+		pkgconf --define-prefix --variable=prefix ${basedir}/lib-relocatable/lib/pkgconfig/foo.pc
+}

tests/lib-relocatable/lib/pkgconfig/foo.pc

@@ -0,0 +1,11 @@
+prefix=/test
+exec_prefix=${prefix}
+libdir=${prefix}/lib
+includedir=${prefix}/include
+
+Name: foo
+Description: A testing pkg-config file
+Version: 1.2.3
+Libs: -L${libdir} -lfoo
+Cflags: -fPIC -I${includedir}/foo
+Cflags.private: -DFOO_STATIC