Handle trait return values
[ldk-java] / genbindings.py
index 9f7e136980d1e2787563e2476c79a3a4c737e64e..79f910602b71c1557191861daf08482ed61762d9 100755 (executable)
 #!/usr/bin/env python3
 import sys, re
 
-if len(sys.argv) != 3:
-    print("USAGE: /path/to/lightning.h /path/to/bindings.java")
+if len(sys.argv) != 4:
+    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /path/to/bindings/output.c")
     sys.exit(1)
 
-with open(sys.argv[1]) as f, open(sys.argv[2], "w") as out_f:
-    var_is_arr_regex = re.compile("\(\*([A-za-z_]*)\)\[[0-9]*\]");
-    def map_type(fn_arg, print_void):
+with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.argv[3], "w") as out_c:
+    opaque_structs = set()
+
+    var_is_arr_regex = re.compile("\(\*([A-za-z_]*)\)\[([0-9]*)\]")
+    var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
+    def java_c_types(fn_arg, ret_arr_len):
         fn_arg = fn_arg.strip()
         if fn_arg.startswith("MUST_USE_RES "):
             fn_arg = fn_arg[13:]
         if fn_arg.startswith("const "):
             fn_arg = fn_arg[6:]
+
+        is_ptr = False
         if fn_arg.startswith("void"):
-            if print_void:
-                out_f.write("void")
-            else:
-                return
+            java_ty = "void"
+            c_ty = "void"
             fn_arg = fn_arg.strip("void ")
         elif fn_arg.startswith("bool"):
-            out_f.write("boolean")
+            java_ty = "boolean"
+            c_ty = "jboolean"
             fn_arg = fn_arg.strip("bool ")
         elif fn_arg.startswith("uint8_t"):
-            out_f.write("byte")
+            java_ty = "byte"
+            c_ty = "jbyte"
             fn_arg = fn_arg.strip("uint8_t ")
         elif fn_arg.startswith("uint32_t"):
-            out_f.write("int")
+            java_ty = "int"
+            c_ty = "jint"
             fn_arg = fn_arg.strip("uint32_t ")
         elif fn_arg.startswith("uint64_t"):
-            out_f.write("long")
+            java_ty = "long"
+            c_ty = "jlong"
             fn_arg = fn_arg.strip("uint64_t ")
         else:
-            out_f.write("long")
-            fn_arg = "".join([e + " " for e in fn_arg.split(" ")[1:]]).strip()
+            ma = var_ty_regex.match(fn_arg)
+            java_ty = "long"
+            c_ty = "jlong"
+            fn_arg = ma.group(2)
+            is_ptr = True
+
+        var_is_arr = var_is_arr_regex.match(fn_arg)
+        if var_is_arr is not None or ret_arr_len is not None:
+            java_ty = java_ty + "[]"
+            c_ty = c_ty + "Array"
+        return (java_ty, c_ty, is_ptr)
+
+    def map_type(fn_arg, print_void, ret_arr_len, is_free):
+        fn_arg = fn_arg.strip()
+        if fn_arg.startswith("MUST_USE_RES "):
+            fn_arg = fn_arg[13:]
+        if fn_arg.startswith("const "):
+            fn_arg = fn_arg[6:]
+
+        (java_ty, c_ty, is_ptr) = java_c_types(fn_arg, ret_arr_len)
+        is_ptr_to_obj = None
+        if fn_arg.startswith("void"):
+            if not print_void:
+                return (None, None, None)
+            fn_arg = fn_arg.strip("void ")
+        elif not is_ptr:
+            split = fn_arg.split(" ", 2)
+            if len(split) > 1:
+                fn_arg = split[1]
+            else:
+                fn_arg = ""
+        else:
+            ma = var_ty_regex.match(fn_arg)
+            is_ptr_to_obj = ma.group(1)
+            fn_arg = ma.group(2)
+        assert(c_ty is not None)
+        assert(java_ty is not None)
+        out_c.write(c_ty)
+        out_java.write(java_ty)
+
         var_is_arr = var_is_arr_regex.match(fn_arg)
-        if var_is_arr is not None:
-            out_f.write("[] " + var_is_arr.group(1))
-        elif fn_arg.strip() != "":
-            out_f.write(" " + fn_arg.replace('*', '').strip())
+        no_ptr = fn_arg.replace('*', '')
+        if var_is_arr is not None or ret_arr_len is not None:
+            if var_is_arr is not None:
+                arr_name = var_is_arr.group(1)
+                arr_len = var_is_arr.group(2)
+                out_java.write(" " + arr_name)
+                out_c.write(" " + arr_name)
+            else:
+                arr_name = "ret"
+                arr_len = ret_arr_len
+            assert(c_ty == "jbyteArray")
+            return ("unsigned char " + arr_name + "_arr[" + arr_len + "];\n" +
+                    "(*_env)->GetByteArrayRegion (_env, """ + arr_name + ", 0, " + arr_len + ", " + arr_name + "_arr);\n" +
+                    "unsigned char (*""" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;",
+                (c_ty + " " + arr_name + "_arr = (*_env)->NewByteArray(_env, " + arr_len + ");\n" +
+                    "(*_env)->SetByteArrayRegion(_env, " + arr_name + "_arr, 0, " + arr_len + ", *",
+                    ");\nreturn ret_arr;"),
+                arr_name + "_ref")
+        elif no_ptr.strip() != "":
+            # If we have a parameter name, print it (noting that it may indicate its a pointer)
+            out_java.write(" " + no_ptr.strip())
+            out_c.write(" " + no_ptr.strip())
+            if is_ptr_to_obj is not None:
+                if no_ptr == fn_arg:
+                    base_conv = is_ptr_to_obj + " " + no_ptr.strip() + "_conv = *(" + is_ptr_to_obj + "*)" + no_ptr.strip() + ";\nfree((void*)" + no_ptr.strip() + ");";
+                    if is_ptr_to_obj in opaque_structs:
+                        return (base_conv + "\n" + no_ptr.strip() + "_conv._underlying_ref = false;",
+                            "XXX2", no_ptr.strip() + "_conv")
+                    return (base_conv, "XXX2", no_ptr.strip() + "_conv")
+                else:
+                    assert(not is_free)
+                    return (is_ptr_to_obj + "* " + no_ptr.strip() + "_conv = (" + is_ptr_to_obj + "*)" + no_ptr.strip() + ";",
+                            "XXX2", no_ptr.strip() + "_conv")
+            elif no_ptr != fn_arg:
+                return ("YYY1", "XXX3", no_ptr.strip())
+            else:
+                return (None, "XXX4", no_ptr.strip())
         elif not print_void:
-            out_f.write(" arg");
+            # We don't have a parameter name, and want one, just call it arg
+            out_java.write(" arg")
+            out_c.write(" arg")
+            if is_ptr_to_obj is not None:
+                assert(not is_free or is_ptr_to_obj not in opaque_structs);
+                return (is_ptr_to_obj + " arg_conv = *(" + is_ptr_to_obj + "*)arg;\nfree((void*)arg);", "XXX2", "arg_conv")
+            else:
+                assert(not is_free)
+                return (None, "XXX6", "arg")
+        else:
+            # We don't have a parameter name, and don't want one (cause we're returning)
+            if is_ptr_to_obj is not None:
+                if no_ptr == fn_arg:
+                    if is_ptr_to_obj in opaque_structs:
+                        # If we're returning a newly-allocated struct, we don't want Rust to ever
+                        # free, instead relying on the Java GC to lose the ref. We undo this in
+                        # any _free function.
+                        # To avoid any issues, we first assert that the incoming object is non-ref.
+                        return (None, (is_ptr_to_obj + "* ret = malloc(sizeof(" + is_ptr_to_obj + "));\n*ret = ", ";\nassert(!ret->_underlying_ref);\nret->_underlying_ref = true;\nreturn (long)ret;"), None)
+                    else:
+                        return (None, (is_ptr_to_obj + "* ret = malloc(sizeof(" + is_ptr_to_obj + "));\n*ret = ", ";\nreturn (long)ret;"), None)
+                else:
+                    return (None, ("return (long) ", ";"), None)
+            else:
+                return (None, None, None)
+
+    def map_fn(re_match, ret_arr_len):
+        out_java.write("\t/// " + line)
+        out_java.write("\tpublic static native ")
+        out_c.write("JNIEXPORT ")
+
+        _, ret_conv, _ = map_type(re_match.group(1), True, ret_arr_len, False)
+        if ret_conv is not None:
+            ret_conv_pfx, ret_conv_sfx = ret_conv
+
+        out_java.write(" " + re_match.group(2) + "(")
+        out_c.write(" JNICALL Java_org_ldk_impl_bindings_" + re_match.group(2).replace('_', '_1') + "(JNIEnv * _env, jclass _b")
 
-    def map_fn_args(fn_args):
-        for idx, arg in enumerate(fn_args.split(',')):
+        arg_names = []
+        for idx, arg in enumerate(re_match.group(3).split(',')):
             if idx != 0:
-                out_f.write(", ")
-            map_type(arg, False)
+                out_java.write(", ")
+            if arg != "void":
+                out_c.write(", ")
+            arg_names.append(map_type(arg, False, None, re_match.group(2).endswith("_free")))
 
-    def map_fn(re_match, ret_ty_suffix):
-        out_f.write("\t/// " + line)
-        out_f.write("\tpublic static native ")
-        map_type(re_match.group(1), True)
-        out_f.write(ret_ty_suffix + " " + re_match.group(2).replace('_', '') + "(")
-        map_fn_args(re_match.group(3))
-        out_f.write(");\n")
+        out_java.write(");\n")
+        out_c.write(") {\n")
+
+        for arg_conv, _, _ in arg_names:
+            if arg_conv is not None:
+                out_c.write("\t" + arg_conv.replace('\n', "\n\t") + "\n");
+
+        if ret_conv is not None:
+            out_c.write("\t" + ret_conv_pfx.replace('\n', '\n\t'));
+        else:
+            out_c.write("\treturn ");
+
+        out_c.write(re_match.group(2) + "(")
+        for idx, (_, _, arg) in enumerate(arg_names):
+            if arg is not None:
+                if idx != 0:
+                    out_c.write(", ")
+                out_c.write(arg)
+        out_c.write(")")
+        if ret_conv is not None:
+            out_c.write(ret_conv_sfx.replace('\n', '\n\t'))
+        else:
+            out_c.write(";")
+        out_c.write("\n}\n\n")
 
-    out_f.write("""package org.ldk;
+    out_java.write("""package org.ldk.impl;
 
 public class bindings {
        static {
-               System.loadLibrary(\"lightning\");
+               System.loadLibrary(\"lightningjni\");
        }
 
 """)
+    out_c.write("#include \"org_ldk_impl_bindings.h\"\n")
+    out_c.write("#include <rust_types.h>\n")
+    out_c.write("#include <lightning.h>\n")
+    out_c.write("#include <assert.h>\n\n")
+    out_c.write("#include <string.h>\n\n")
 
     in_block_comment = False
     in_block_enum = False
-    in_block_struct = False
+    cur_block_struct = None
     in_block_union = False
 
     fn_ptr_regex = re.compile("^extern const ([A-Za-z_0-9\* ]*) \(\*(.*)\)\((.*)\);$")
-    fn_ret_arr_regex = re.compile("(.*) \(\*(.*)\((.*)\)\)\[.*\];$")
-    reg_fn_regex = re.compile("([A-Za-z_0-9\* ]*) \*?([a-zA-Z_0-9]*)\((.*)\);$")
+    fn_ret_arr_regex = re.compile("(.*) \(\*(.*)\((.*)\)\)\[([0-9]*)\];$")
+    reg_fn_regex = re.compile("([A-Za-z_0-9\* ]* \*?)([a-zA-Z_0-9]*)\((.*)\);$")
+    const_val_regex = re.compile("^extern const ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
 
-    for line in f:
+    line_indicates_opaque_regex = re.compile("^   bool _underlying_ref;$")
+    line_indicates_trait_regex = re.compile("^   ([A-Za-z_0-9]* \*?)\(\*([A-Za-z_0-9]*)\)\((const )?void \*this_arg.*\);$")
+    assert(line_indicates_trait_regex.match("   uintptr_t (*send_data)(void *this_arg, LDKu8slice data, bool resume_read);"))
+    assert(line_indicates_trait_regex.match("   LDKCVec_MessageSendEventZ (*get_and_clear_pending_msg_events)(const void *this_arg);"))
+    assert(line_indicates_trait_regex.match("   void *(*clone)(const void *this_arg);"))
+    struct_name_regex = re.compile("^typedef struct (MUST_USE_STRUCT )?(LDK[A-Za-z_0-9]*) {$")
+    assert(struct_name_regex.match("typedef struct LDKCVecTempl_u8 {"))
+
+    for line in in_h:
         if in_block_comment:
-            #out_f.write("\t" + line)
+            #out_java.write("\t" + line)
             if line.endswith("*/\n"):
                 in_block_comment = False
-        elif in_block_struct:
+        elif cur_block_struct is not None:
+            cur_block_struct  = cur_block_struct + line
             if line.startswith("} "):
-                in_block_struct = False
+                field_lines = []
+                struct_name = None
+                struct_lines = cur_block_struct.split("\n")
+                is_opaque = False
+                trait_fn_lines = []
+
+                for idx, struct_line in enumerate(struct_lines):
+                    if struct_line.strip().startswith("/*"):
+                        in_block_comment = True
+                    if in_block_comment:
+                        if struct_line.endswith("*/"):
+                            in_block_comment = False
+                    else:
+                        struct_name_match = struct_name_regex.match(struct_line)
+                        if struct_name_match is not None:
+                            struct_name = struct_name_match.group(2)
+                        if line_indicates_opaque_regex.match(struct_line):
+                            is_opaque = True
+                        trait_fn_match = line_indicates_trait_regex.match(struct_line)
+                        if trait_fn_match is not None:
+                            trait_fn_lines.append(trait_fn_match)
+                        field_lines.append(struct_line)
+
+                assert(struct_name is not None)
+                assert(len(trait_fn_lines) == 0 or not is_opaque)
+                if is_opaque:
+                    opaque_structs.add(struct_name)
+                if len(trait_fn_lines) > 0:
+                    out_c.write("typedef struct " + struct_name + "_JCalls {\n")
+                    out_c.write("\tJNIEnv *env;\n")
+                    out_c.write("\tjobject o;\n")
+                    for fn_line in trait_fn_lines:
+                        if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                            out_c.write("\tjmethodID " + fn_line.group(2) + "_meth;\n")
+                    out_c.write("} " + struct_name + "_JCalls;\n")
+
+                    out_java.write("\tpublic interface " + struct_name + " {\n")
+                    for fn_line in trait_fn_lines:
+                        if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                            (java_ty, c_ty, is_ptr) = java_c_types(fn_line.group(1), None)
+
+                            out_java.write("\t\t " + java_ty + " " + fn_line.group(2) + "(/* TODO */);\n")
+
+                            out_c.write(c_ty + " " + fn_line.group(2) + "_jcall(void* this_arg/* TODO */) {\n")
+                            out_c.write("\t" + struct_name + "_JCalls *arg = (" + struct_name + "_JCalls*) this_arg;\n")
+                            out_c.write("\treturn (*arg->env)->Call" + java_ty.title() + "Method(arg->env, arg->o, arg->" + fn_line.group(2) + "_meth);\n");
+                            out_c.write("}\n")
+                        elif fn_line.group(2) == "free":
+                            out_c.write("void " + struct_name + "_JCalls_free(void* this_arg) {\n")
+                            out_c.write("\t" + struct_name + "_JCalls *arg = (" + struct_name + "_JCalls*) this_arg;\n")
+                            out_c.write("\t(*arg->env)->DeleteGlobalRef(arg->env, arg->o);\n")
+                            out_c.write("\tfree(arg);\n")
+                            out_c.write("}\n")
+                        elif fn_line.group(2) == "clone":
+                            out_c.write("void* " + struct_name + "_JCalls_clone(void* this_arg) {\n")
+                            out_c.write("\t" + struct_name + "_JCalls *ret = malloc(sizeof(" + struct_name + "_JCalls));\n")
+                            out_c.write("\tmemcpy(ret, this_arg, sizeof(" + struct_name + "_JCalls));\n")
+                            out_c.write("\treturn ret;\n")
+                            out_c.write("}\n")
+                    out_java.write("\t}\n")
+                    out_java.write("\tpublic static native long " + struct_name + "_new(" + struct_name + " impl);\n")
+
+                    out_c.write("JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new (JNIEnv * env, jclass _a, jobject o) {\n")
+                    out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\n")
+                    out_c.write("\tassert(c != NULL);\n")
+                    out_c.write("\t" + struct_name + "_JCalls *calls = malloc(sizeof(" + struct_name + "_JCalls));\n")
+                    out_c.write("\tcalls->env = env;\n")
+                    out_c.write("\tcalls->o = (*env)->NewGlobalRef(env, o);\n")
+                    for fn_line in trait_fn_lines:
+                        if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                            out_c.write("\tcalls->" + fn_line.group(2) + "_meth = (*env)->GetMethodID(env, c, \"" + fn_line.group(2) + "\", \"" + "TODO" + "\");\n")
+                            out_c.write("\tassert(calls->" + fn_line.group(2) + "_meth != NULL);\n")
+                    out_c.write("\n\t" + struct_name + " *ret = malloc(sizeof(" + struct_name + "));\n")
+                    out_c.write("\tret->this_arg = (void*) calls;\n")
+                    for fn_line in trait_fn_lines:
+                        if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                            out_c.write("\tret->" + fn_line.group(2) + " = " + fn_line.group(2) + "_jcall;\n")
+                        elif fn_line.group(2) == "free":
+                            out_c.write("\tret->free = " + struct_name + "_JCalls_free;\n")
+                        else:
+                            out_c.write("\tret->clone = " + struct_name + "_JCalls_clone;\n")
+                    out_c.write("\treturn (long)ret;\n")
+                    out_c.write("}\n\n")
+
+                    #out_java.write("/* " + "\n".join(field_lines) + "*/\n")
+                cur_block_struct = None
         elif in_block_union:
             if line.startswith("} "):
                 in_block_union = False
@@ -92,28 +325,32 @@ public class bindings {
             fn_ptr = fn_ptr_regex.match(line)
             fn_ret_arr = fn_ret_arr_regex.match(line)
             reg_fn = reg_fn_regex.match(line)
+            const_val = const_val_regex.match(line)
 
             if line.startswith("#include <"):
                 pass
             elif line.startswith("/*"):
-                #out_f.write("\t" + line)
+                #out_java.write("\t" + line)
                 if not line.endswith("*/\n"):
                     in_block_comment = True
             elif line.startswith("typedef enum "):
                 in_block_enum = True
             elif line.startswith("typedef struct "):
-                in_block_struct = True
+                cur_block_struct = line
             elif line.startswith("typedef union "):
                 in_block_union = True
             elif line.startswith("typedef "):
                 pass
             elif fn_ptr is not None:
-                map_fn(fn_ptr, "")
+                map_fn(fn_ptr, None)
             elif fn_ret_arr is not None:
-                map_fn(fn_ret_arr, "[]")
+                map_fn(fn_ret_arr, fn_ret_arr.group(4))
             elif reg_fn is not None:
-                map_fn(reg_fn, "")
+                map_fn(reg_fn, None)
+            elif const_val_regex is not None:
+                # TODO Map const variables
+                pass
             else:
                 assert(line == "\n")
 
-    out_f.write("}\n");
+    out_java.write("}\n")