diff --git a/src/stage0/CMakeLists.txt b/src/stage0/CMakeLists.txt
index 90e2123b61..845e2427a5 100644
--- a/src/stage0/CMakeLists.txt
+++ b/src/stage0/CMakeLists.txt
@@ -1 +1 @@
-add_library (stage0 OBJECT ./init/coe.cpp ./init/control/alternative.cpp ./init/control/applicative.cpp ./init/control/combinators.cpp ./init/control/conditional.cpp ./init/control/default.cpp ./init/control/estate.cpp ./init/control/except.cpp ./init/control/functor.cpp ./init/control/id.cpp ./init/control/lift.cpp ./init/control/monad.cpp ./init/control/monadfail.cpp ./init/control/option.cpp ./init/control/reader.cpp ./init/control/state.cpp ./init/core.cpp ./init/data/array/basic.cpp ./init/data/array/binsearch.cpp ./init/data/array/default.cpp ./init/data/array/qsort.cpp ./init/data/assoclist.cpp ./init/data/basic.cpp ./init/data/bytearray/basic.cpp ./init/data/bytearray/default.cpp ./init/data/char/basic.cpp ./init/data/char/default.cpp ./init/data/default.cpp ./init/data/dlist.cpp ./init/data/fin/basic.cpp ./init/data/fin/default.cpp ./init/data/hashable.cpp ./init/data/hashmap/basic.cpp ./init/data/hashmap/default.cpp ./init/data/int/basic.cpp ./init/data/int/default.cpp ./init/data/list/basic.cpp ./init/data/list/default.cpp ./init/data/list/instances.cpp ./init/data/nat/basic.cpp ./init/data/nat/bitwise.cpp ./init/data/nat/default.cpp ./init/data/nat/div.cpp ./init/data/option/basic.cpp ./init/data/option/instances.cpp ./init/data/ordering/basic.cpp ./init/data/ordering/default.cpp ./init/data/persistentarray/basic.cpp ./init/data/persistentarray/default.cpp ./init/data/random.cpp ./init/data/rbmap/basic.cpp ./init/data/rbmap/default.cpp ./init/data/rbtree/basic.cpp ./init/data/rbtree/default.cpp ./init/data/repr.cpp ./init/data/string/basic.cpp ./init/data/string/default.cpp ./init/data/tostring.cpp ./init/data/uint.cpp ./init/default.cpp ./init/fix.cpp ./init/lean/attributes.cpp ./init/lean/class.cpp ./init/lean/compiler/closedtermcache.cpp ./init/lean/compiler/constfolding.cpp ./init/lean/compiler/default.cpp ./init/lean/compiler/exportattr.cpp ./init/lean/compiler/externattr.cpp ./init/lean/compiler/implementedbyattr.cpp ./init/lean/compiler/initattr.cpp ./init/lean/compiler/inlineattrs.cpp ./init/lean/compiler/ir/basic.cpp ./init/lean/compiler/ir/borrow.cpp ./init/lean/compiler/ir/boxing.cpp ./init/lean/compiler/ir/checker.cpp ./init/lean/compiler/ir/compilerm.cpp ./init/lean/compiler/ir/default.cpp ./init/lean/compiler/ir/elimdead.cpp ./init/lean/compiler/ir/emitcpp.cpp ./init/lean/compiler/ir/emitutil.cpp ./init/lean/compiler/ir/expandresetreuse.cpp ./init/lean/compiler/ir/format.cpp ./init/lean/compiler/ir/freevars.cpp ./init/lean/compiler/ir/livevars.cpp ./init/lean/compiler/ir/normids.cpp ./init/lean/compiler/ir/pushproj.cpp ./init/lean/compiler/ir/rc.cpp ./init/lean/compiler/ir/resetreuse.cpp ./init/lean/compiler/ir/simpcase.cpp ./init/lean/compiler/namemangling.cpp ./init/lean/compiler/specialize.cpp ./init/lean/compiler/util.cpp ./init/lean/declaration.cpp ./init/lean/default.cpp ./init/lean/elaborator/alias.cpp ./init/lean/elaborator/basic.cpp ./init/lean/elaborator/command.cpp ./init/lean/elaborator/default.cpp ./init/lean/elaborator/elabstrategyattrs.cpp ./init/lean/environment.cpp ./init/lean/eqncompiler/default.cpp ./init/lean/eqncompiler/matchpattern.cpp ./init/lean/expr.cpp ./init/lean/format.cpp ./init/lean/kvmap.cpp ./init/lean/level.cpp ./init/lean/message.cpp ./init/lean/modifiers.cpp ./init/lean/name.cpp ./init/lean/namegenerator.cpp ./init/lean/options.cpp ./init/lean/parser/command.cpp ./init/lean/parser/default.cpp ./init/lean/parser/identifier.cpp ./init/lean/parser/level.cpp ./init/lean/parser/module.cpp ./init/lean/parser/parser.cpp ./init/lean/parser/term.cpp ./init/lean/parser/trie.cpp ./init/lean/position.cpp ./init/lean/projfns.cpp ./init/lean/reducibilityattrs.cpp ./init/lean/runtime.cpp ./init/lean/scopes.cpp ./init/lean/smap.cpp ./init/lean/syntax.cpp ./init/lean/toexpr.cpp ./init/lean/trace.cpp ./init/lean/util.cpp ./init/system/default.cpp ./init/system/io.cpp ./init/system/platform.cpp ./init/util.cpp ./init/wf.cpp)
+add_library (stage0 OBJECT ./init/coe.cpp ./init/control/alternative.cpp ./init/control/applicative.cpp ./init/control/combinators.cpp ./init/control/conditional.cpp ./init/control/default.cpp ./init/control/estate.cpp ./init/control/except.cpp ./init/control/functor.cpp ./init/control/id.cpp ./init/control/lift.cpp ./init/control/monad.cpp ./init/control/monadfail.cpp ./init/control/option.cpp ./init/control/reader.cpp ./init/control/state.cpp ./init/core.cpp ./init/data/array/basic.cpp ./init/data/array/binsearch.cpp ./init/data/array/default.cpp ./init/data/array/qsort.cpp ./init/data/assoclist.cpp ./init/data/basic.cpp ./init/data/bytearray/basic.cpp ./init/data/bytearray/default.cpp ./init/data/char/basic.cpp ./init/data/char/default.cpp ./init/data/default.cpp ./init/data/dlist.cpp ./init/data/fin/basic.cpp ./init/data/fin/default.cpp ./init/data/hashable.cpp ./init/data/hashmap/basic.cpp ./init/data/hashmap/default.cpp ./init/data/int/basic.cpp ./init/data/int/default.cpp ./init/data/list/basic.cpp ./init/data/list/default.cpp ./init/data/list/instances.cpp ./init/data/nat/basic.cpp ./init/data/nat/bitwise.cpp ./init/data/nat/default.cpp ./init/data/nat/div.cpp ./init/data/option/basic.cpp ./init/data/option/instances.cpp ./init/data/ordering/basic.cpp ./init/data/ordering/default.cpp ./init/data/persistentarray/basic.cpp ./init/data/persistentarray/default.cpp ./init/data/random.cpp ./init/data/rbmap/basic.cpp ./init/data/rbmap/default.cpp ./init/data/rbtree/basic.cpp ./init/data/rbtree/default.cpp ./init/data/repr.cpp ./init/data/string/basic.cpp ./init/data/string/default.cpp ./init/data/tostring.cpp ./init/data/uint.cpp ./init/default.cpp ./init/fix.cpp ./init/lean/attributes.cpp ./init/lean/class.cpp ./init/lean/compiler/closedtermcache.cpp ./init/lean/compiler/constfolding.cpp ./init/lean/compiler/default.cpp ./init/lean/compiler/exportattr.cpp ./init/lean/compiler/externattr.cpp ./init/lean/compiler/implementedbyattr.cpp ./init/lean/compiler/initattr.cpp ./init/lean/compiler/inlineattrs.cpp ./init/lean/compiler/ir/basic.cpp ./init/lean/compiler/ir/borrow.cpp ./init/lean/compiler/ir/boxing.cpp ./init/lean/compiler/ir/checker.cpp ./init/lean/compiler/ir/compilerm.cpp ./init/lean/compiler/ir/default.cpp ./init/lean/compiler/ir/elimdead.cpp ./init/lean/compiler/ir/emitcpp.cpp ./init/lean/compiler/ir/emitutil.cpp ./init/lean/compiler/ir/expandresetreuse.cpp ./init/lean/compiler/ir/format.cpp ./init/lean/compiler/ir/freevars.cpp ./init/lean/compiler/ir/livevars.cpp ./init/lean/compiler/ir/normids.cpp ./init/lean/compiler/ir/pushproj.cpp ./init/lean/compiler/ir/rc.cpp ./init/lean/compiler/ir/resetreuse.cpp ./init/lean/compiler/ir/simpcase.cpp ./init/lean/compiler/namemangling.cpp ./init/lean/compiler/specialize.cpp ./init/lean/compiler/util.cpp ./init/lean/declaration.cpp ./init/lean/default.cpp ./init/lean/elaborator/alias.cpp ./init/lean/elaborator/basic.cpp ./init/lean/elaborator/command.cpp ./init/lean/elaborator/default.cpp ./init/lean/elaborator/elabstrategyattrs.cpp ./init/lean/environment.cpp ./init/lean/eqncompiler/default.cpp ./init/lean/eqncompiler/matchpattern.cpp ./init/lean/expr.cpp ./init/lean/format.cpp ./init/lean/kvmap.cpp ./init/lean/level.cpp ./init/lean/message.cpp ./init/lean/modifiers.cpp ./init/lean/name.cpp ./init/lean/namegenerator.cpp ./init/lean/options.cpp ./init/lean/parser/command.cpp ./init/lean/parser/default.cpp ./init/lean/parser/identifier.cpp ./init/lean/parser/level.cpp ./init/lean/parser/module.cpp ./init/lean/parser/parser.cpp ./init/lean/parser/term.cpp ./init/lean/parser/trie.cpp ./init/lean/position.cpp ./init/lean/projfns.cpp ./init/lean/reducibilityattrs.cpp ./init/lean/runtime.cpp ./init/lean/scopes.cpp ./init/lean/smap.cpp ./init/lean/syntax.cpp ./init/lean/toexpr.cpp ./init/lean/trace.cpp ./init/lean/util.cpp ./init/system/default.cpp ./init/system/filepath.cpp ./init/system/io.cpp ./init/system/platform.cpp ./init/util.cpp ./init/wf.cpp)
diff --git a/src/stage0/init/system/filepath.cpp b/src/stage0/init/system/filepath.cpp
new file mode 100644
index 0000000000..eddcc01c30
--- /dev/null
+++ b/src/stage0/init/system/filepath.cpp
@@ -0,0 +1,167 @@
+// Lean compiler output
+// Module: init.system.filepath
+// Imports: init.system.platform init.data.char.basic
+#include "runtime/object.h"
+#include "runtime/apply.h"
+typedef lean::object obj;    typedef lean::usize  usize;
+typedef lean::uint8  uint8;  typedef lean::uint16 uint16;
+typedef lean::uint32 uint32; typedef lean::uint64 uint64;
+#if defined(__clang__)
+#pragma clang diagnostic ignored "-Wunused-parameter"
+#pragma clang diagnostic ignored "-Wunused-label"
+#elif defined(__GNUC__) && !defined(__CLANG__)
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#pragma GCC diagnostic ignored "-Wunused-label"
+#pragma GCC diagnostic ignored "-Wunused-but-set-variable"
+#endif
+uint32 l_System_FilePath_pathSeparator___closed__1;
+obj* l_System_FilePath_pathSeparators___closed__3;
+extern uint8 l_System_Platform_isWindows;
+obj* l_System_FilePath_pathSeparators___closed__2;
+uint32 l_System_FilePath_searchPathSeparator;
+obj* l_System_FilePath_pathSeparators;
+obj* l_System_FilePath_pathSeparators___closed__1;
+uint32 l_System_FilePath_searchPathSeparator___closed__1;
+uint32 l_System_FilePath_extSeparator;
+uint32 l_System_FilePath_pathSeparator;
+uint32 _init_l_System_FilePath_pathSeparator___closed__1() {
+_start:
+{
+uint8 x_1; 
+x_1 = l_System_Platform_isWindows;
+if (x_1 == 0)
+{
+uint32 x_2; 
+x_2 = 47;
+return x_2;
+}
+else
+{
+uint32 x_3; 
+x_3 = 92;
+return x_3;
+}
+}
+}
+uint32 _init_l_System_FilePath_pathSeparator() {
+_start:
+{
+uint32 x_1; 
+x_1 = l_System_FilePath_pathSeparator___closed__1;
+return x_1;
+}
+}
+obj* _init_l_System_FilePath_pathSeparators___closed__1() {
+_start:
+{
+uint32 x_1; obj* x_2; obj* x_3; obj* x_4; 
+x_1 = 47;
+x_2 = lean::box(0);
+x_3 = lean::box_uint32(x_1);
+x_4 = lean::alloc_cnstr(1, 2, 0);
+lean::cnstr_set(x_4, 0, x_3);
+lean::cnstr_set(x_4, 1, x_2);
+return x_4;
+}
+}
+obj* _init_l_System_FilePath_pathSeparators___closed__2() {
+_start:
+{
+uint32 x_1; obj* x_2; obj* x_3; obj* x_4; 
+x_1 = 92;
+x_2 = l_System_FilePath_pathSeparators___closed__1;
+x_3 = lean::box_uint32(x_1);
+x_4 = lean::alloc_cnstr(1, 2, 0);
+lean::cnstr_set(x_4, 0, x_3);
+lean::cnstr_set(x_4, 1, x_2);
+return x_4;
+}
+}
+obj* _init_l_System_FilePath_pathSeparators___closed__3() {
+_start:
+{
+uint8 x_1; 
+x_1 = l_System_Platform_isWindows;
+if (x_1 == 0)
+{
+obj* x_2; 
+x_2 = l_System_FilePath_pathSeparators___closed__1;
+return x_2;
+}
+else
+{
+obj* x_3; 
+x_3 = l_System_FilePath_pathSeparators___closed__2;
+return x_3;
+}
+}
+}
+obj* _init_l_System_FilePath_pathSeparators() {
+_start:
+{
+obj* x_1; 
+x_1 = l_System_FilePath_pathSeparators___closed__3;
+return x_1;
+}
+}
+uint32 _init_l_System_FilePath_searchPathSeparator___closed__1() {
+_start:
+{
+uint8 x_1; 
+x_1 = l_System_Platform_isWindows;
+if (x_1 == 0)
+{
+uint32 x_2; 
+x_2 = 58;
+return x_2;
+}
+else
+{
+uint32 x_3; 
+x_3 = 59;
+return x_3;
+}
+}
+}
+uint32 _init_l_System_FilePath_searchPathSeparator() {
+_start:
+{
+uint32 x_1; 
+x_1 = l_System_FilePath_searchPathSeparator___closed__1;
+return x_1;
+}
+}
+uint32 _init_l_System_FilePath_extSeparator() {
+_start:
+{
+uint32 x_1; 
+x_1 = 46;
+return x_1;
+}
+}
+obj* initialize_init_system_platform(obj*);
+obj* initialize_init_data_char_basic(obj*);
+static bool _G_initialized = false;
+obj* initialize_init_system_filepath(obj* w) {
+if (_G_initialized) return w;
+_G_initialized = true;
+if (io_result_is_error(w)) return w;
+w = initialize_init_system_platform(w);
+if (io_result_is_error(w)) return w;
+w = initialize_init_data_char_basic(w);
+if (io_result_is_error(w)) return w;
+l_System_FilePath_pathSeparator___closed__1 = _init_l_System_FilePath_pathSeparator___closed__1();
+l_System_FilePath_pathSeparator = _init_l_System_FilePath_pathSeparator();
+l_System_FilePath_pathSeparators___closed__1 = _init_l_System_FilePath_pathSeparators___closed__1();
+lean::mark_persistent(l_System_FilePath_pathSeparators___closed__1);
+l_System_FilePath_pathSeparators___closed__2 = _init_l_System_FilePath_pathSeparators___closed__2();
+lean::mark_persistent(l_System_FilePath_pathSeparators___closed__2);
+l_System_FilePath_pathSeparators___closed__3 = _init_l_System_FilePath_pathSeparators___closed__3();
+lean::mark_persistent(l_System_FilePath_pathSeparators___closed__3);
+l_System_FilePath_pathSeparators = _init_l_System_FilePath_pathSeparators();
+lean::mark_persistent(l_System_FilePath_pathSeparators);
+l_System_FilePath_searchPathSeparator___closed__1 = _init_l_System_FilePath_searchPathSeparator___closed__1();
+l_System_FilePath_searchPathSeparator = _init_l_System_FilePath_searchPathSeparator();
+l_System_FilePath_extSeparator = _init_l_System_FilePath_extSeparator();
+return w;
+}