main: add --with-path CLI option (closes #104)

main.c

@@ -577,6 +577,7 @@ usage(void)
 	printf("  --no-cache                        do not cache already seen packages when\n");
 	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("\nchecking specific pkg-config database entries:\n\n");
 
@@ -681,6 +682,7 @@ main(int argc, char *argv[])
 		{ "validate", no_argument, NULL, 0 },
 		{ "log-file", required_argument, NULL, 40 },
 		{ "path", no_argument, &want_flags, PKG_PATH },
+		{ "with-path", required_argument, NULL, 42 },
 		{ NULL, 0, NULL, 0 }
 	};
 
@@ -714,6 +716,9 @@ main(int argc, char *argv[])
 		case 40:
 			logfile_arg = pkg_optarg;
 			break;
+		case 42:
+			pkgconf_path_add(pkg_optarg, &pkg_client.dir_list, true);
+			break;
 		case '?':
 		case ':':
 			return EXIT_FAILURE;

pkgconf.1

@@ -65,6 +65,9 @@ flag.
 Ignore
 .Sq Provides
 rules in modules when resolving dependencies.
+.It Fl -with-path Ns = Ns Ar PATH
+Adds a new module search path to pkgconf's dependency resolver.  Paths added in
+this way are given preference before other paths.
 .El
 .Sh MODULE-SPECIFIC OPTIONS
 .Bl -tag -width indent

tests/basic.sh

@@ -32,7 +32,8 @@ tests_init \
 	pkg_config_path \
 	nolibs \
 	nocflags \
-	arbitary_path
+	arbitary_path \
+	with_path
 
 noargs_body()
 {
@@ -255,6 +256,16 @@ pkg_config_path_body()
 		pkgconf --libs bar
 }
 
+with_path_body()
+{
+	atf_check \
+		-o inline:"-L/test/lib -lfoo  \n" \
+		pkgconf --with-path=${selfdir}/lib1 --with-path=${selfdir}/lib2 --libs foo
+	atf_check \
+		-o inline:"-L/test/lib -lbar -lfoo  \n" \
+		pkgconf --with-path=${selfdir}/lib1 --with-path=${selfdir}/lib2 --libs bar
+}
+
 nolibs_body()
 {
 	export PKG_CONFIG_PATH="${selfdir}/lib1"