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-rw-r--r--bindings/lua/upb.c1012
1 files changed, 1012 insertions, 0 deletions
diff --git a/bindings/lua/upb.c b/bindings/lua/upb.c
new file mode 100644
index 0000000..fe523e7
--- /dev/null
+++ b/bindings/lua/upb.c
@@ -0,0 +1,1012 @@
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009 Google Inc. See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * A Lua extension for upb.
+ */
+
+#include <stdlib.h>
+#include <math.h>
+#include <float.h>
+#include "lauxlib.h"
+#include "upb/def.h"
+#include "upb/msg.h"
+#include "upb/pb/glue.h"
+
+#if LUA_VERSION_NUM == 501
+#define lua_rawlen lua_objlen
+#endif
+
+static bool streql(const char *a, const char *b) { return strcmp(a, b) == 0; }
+
+static bool lupb_isint(double n) { return (double)(int)n == n; }
+
+static uint8_t lupb_touint8(lua_State *L, int narg, const char *name) {
+ lua_Number n = lua_tonumber(L, narg);
+ if (n > UINT8_MAX || n < 0 || rint(n) != n)
+ luaL_error(L, "Invalid %s", name);
+ return n;
+}
+
+static uint32_t lupb_touint32(lua_State *L, int narg, const char *name) {
+ lua_Number n = lua_tonumber(L, narg);
+ if (n > UINT32_MAX || n < 0 || rint(n) != n)
+ luaL_error(L, "Invalid %s", name);
+ return n;
+}
+
+static void lupb_pushstring(lua_State *L, upb_strref *ref) {
+ if (ref->ptr) {
+ lua_pushlstring(L, ref->ptr, ref->len);
+ } else {
+ // Lua requires a continguous string; must copy+allocate.
+ char *str = upb_strref_dup(ref);
+ lua_pushlstring(L, str, ref->len);
+ free(str);
+ }
+}
+
+static void lupb_pushvalue(lua_State *L, upb_value val, upb_fielddef *f) {
+ switch (f->type) {
+ case UPB_TYPE(INT32):
+ case UPB_TYPE(SINT32):
+ case UPB_TYPE(SFIXED32):
+ case UPB_TYPE(ENUM):
+ lua_pushnumber(L, upb_value_getint32(val)); break;
+ case UPB_TYPE(INT64):
+ case UPB_TYPE(SINT64):
+ case UPB_TYPE(SFIXED64):
+ lua_pushnumber(L, upb_value_getint64(val)); break;
+ case UPB_TYPE(UINT32):
+ case UPB_TYPE(FIXED32):
+ lua_pushnumber(L, upb_value_getuint32(val)); break;
+ case UPB_TYPE(UINT64):
+ case UPB_TYPE(FIXED64):
+ lua_pushnumber(L, upb_value_getuint64(val)); break;
+ case UPB_TYPE(DOUBLE):
+ lua_pushnumber(L, upb_value_getdouble(val)); break;
+ case UPB_TYPE(FLOAT):
+ lua_pushnumber(L, upb_value_getfloat(val)); break;
+ case UPB_TYPE(BOOL):
+ lua_pushboolean(L, upb_value_getbool(val)); break;
+ default: luaL_error(L, "internal error");
+ }
+}
+
+// Returns a scalar value (ie. not a submessage) as a upb_value.
+static upb_value lupb_getvalue(lua_State *L, int narg, upb_fielddef *f,
+ upb_strref *ref) {
+ assert(!upb_issubmsg(f));
+ upb_value val;
+ if (upb_fielddef_type(f) == UPB_TYPE(BOOL)) {
+ if (!lua_isboolean(L, narg))
+ luaL_error(L, "Must explicitly pass true or false for boolean fields");
+ upb_value_setbool(&val, lua_toboolean(L, narg));
+ } else if (upb_fielddef_type(f) == UPB_TYPE(STRING)) {
+ size_t len;
+ ref->ptr = luaL_checklstring(L, narg, &len);
+ ref->len = len;
+ upb_value_setstrref(&val, ref);
+ } else {
+ // Numeric type.
+ lua_Number num = 0;
+ num = luaL_checknumber(L, narg);
+ switch (upb_fielddef_type(f)) {
+ case UPB_TYPE(INT32):
+ case UPB_TYPE(SINT32):
+ case UPB_TYPE(SFIXED32):
+ case UPB_TYPE(ENUM):
+ if (num > INT32_MAX || num < INT32_MIN || num != rint(num))
+ luaL_error(L, "Cannot convert %f to 32-bit integer", num);
+ upb_value_setint32(&val, num);
+ break;
+ case UPB_TYPE(INT64):
+ case UPB_TYPE(SINT64):
+ case UPB_TYPE(SFIXED64):
+ if (num > INT64_MAX || num < INT64_MIN || num != rint(num))
+ luaL_error(L, "Cannot convert %f to 64-bit integer", num);
+ upb_value_setint64(&val, num);
+ break;
+ case UPB_TYPE(UINT32):
+ case UPB_TYPE(FIXED32):
+ if (num > UINT32_MAX || num < 0 || num != rint(num))
+ luaL_error(L, "Cannot convert %f to unsigned 32-bit integer", num);
+ upb_value_setuint32(&val, num);
+ break;
+ case UPB_TYPE(UINT64):
+ case UPB_TYPE(FIXED64):
+ if (num > UINT64_MAX || num < 0 || num != rint(num))
+ luaL_error(L, "Cannot convert %f to unsigned 64-bit integer", num);
+ upb_value_setuint64(&val, num);
+ break;
+ case UPB_TYPE(DOUBLE):
+ if (num > DBL_MAX || num < -DBL_MAX) {
+ // This could happen if lua_Number was long double.
+ luaL_error(L, "Cannot convert %f to double", num);
+ }
+ upb_value_setdouble(&val, num);
+ break;
+ case UPB_TYPE(FLOAT):
+ if (num > FLT_MAX || num < -FLT_MAX)
+ luaL_error(L, "Cannot convert %f to float", num);
+ upb_value_setfloat(&val, num);
+ break;
+ }
+ }
+ return val;
+}
+
+static void lupb_typecheck(lua_State *L, int narg, upb_fielddef *f) {
+ upb_strref ref;
+ lupb_getvalue(L, narg, f, &ref);
+}
+
+//static void lupb_msg_getorcreate(lua_State *L, upb_msg *msg, upb_msgdef *md);
+static void lupb_fielddef_getorcreate(lua_State *L, upb_fielddef *f);
+static upb_msgdef *lupb_msgdef_check(lua_State *L, int narg);
+static void lupb_msg_pushnew(lua_State *L, void *md);
+
+void lupb_checkstatus(lua_State *L, upb_status *s) {
+ if (!upb_ok(s)) {
+ upb_status_print(s, stderr);
+ // Need to copy the string to the stack, so we can free it and not leak
+ // it (since luaL_error() does not return).
+ char buf[strlen(s->str)+1];
+ strcpy(buf, s->str);
+ upb_status_uninit(s);
+ luaL_error(L, "%s", buf);
+ }
+ upb_status_uninit(s);
+}
+
+
+/* object cache ***************************************************************/
+
+// We cache all the lua objects (userdata) we vend in a weak table, indexed by
+// the C pointer of the object they are caching.
+
+static void *lupb_cache_getorcreate_size(
+ lua_State *L, void *cobj, const char *type, size_t size) {
+ // Lookup our cache in the registry (we don't put our objects in the registry
+ // directly because we need our cache to be a weak table).
+ void **obj = NULL;
+ lua_getfield(L, LUA_REGISTRYINDEX, "upb.objcache");
+ assert(!lua_isnil(L, -1)); // Should have been created by luaopen_upb.
+ lua_pushlightuserdata(L, cobj);
+ lua_rawget(L, -2);
+ // Stack: objcache, cached value.
+ if (lua_isnil(L, -1)) {
+ // Remove bad cached value and push new value.
+ lua_pop(L, 1);
+ // We take advantage of the fact that all of our objects are currently a
+ // single pointer, and thus have the same layout.
+ obj = lua_newuserdata(L, size);
+ *obj = cobj;
+ luaL_getmetatable(L, type);
+ assert(!lua_isnil(L, -1)); // Should have been created by luaopen_upb.
+ lua_setmetatable(L, -2);
+
+ // Set it in the cache.
+ lua_pushlightuserdata(L, cobj);
+ lua_pushvalue(L, -2);
+ lua_rawset(L, -4);
+ }
+ lua_insert(L, -2);
+ lua_pop(L, 1);
+ return obj;
+}
+
+// Most types are just 1 pointer and can use this helper.
+static bool lupb_cache_getorcreate(lua_State *L, void *cobj, const char *type) {
+ return lupb_cache_getorcreate_size(L, cobj, type, sizeof(void*)) != NULL;
+}
+
+static void lupb_cache_create(lua_State *L, void *cobj, const char *type) {
+ bool created =
+ lupb_cache_getorcreate_size(L, cobj, type, sizeof(void*)) != NULL;
+ (void)created; // For NDEBUG
+ assert(created);
+}
+
+
+/* lupb_def *******************************************************************/
+
+// All the def types share the same C layout, even though they are different Lua
+// types with different metatables.
+typedef struct {
+ upb_def *def;
+} lupb_def;
+
+static lupb_def *lupb_def_check(lua_State *L, int narg) {
+ void *ldef = luaL_checkudata(L, narg, "upb.msgdef");
+ if (!ldef) ldef = luaL_checkudata(L, narg, "upb.enumdef");
+ if (!ldef) luaL_typerror(L, narg, "upb def");
+ return ldef;
+}
+
+static void lupb_def_getorcreate(lua_State *L, upb_def *def, int owned) {
+ bool created = false;
+ switch(def->type) {
+ case UPB_DEF_MSG:
+ created = lupb_cache_getorcreate(L, def, "upb.msgdef");
+ break;
+ case UPB_DEF_ENUM:
+ created = lupb_cache_getorcreate(L, def, "upb.enumdef");
+ break;
+ default:
+ luaL_error(L, "unknown deftype %d", def->type);
+ }
+ if (!owned && created) {
+ upb_def_ref(def);
+ } else if (owned && !created) {
+ upb_def_unref(def);
+ }
+}
+
+
+/* lupb_fielddef **************************************************************/
+
+typedef struct {
+ upb_fielddef *field;
+} lupb_fielddef;
+
+static lupb_fielddef *lupb_fielddef_check(lua_State *L, int narg) {
+ lupb_fielddef *f = luaL_checkudata(L, narg, "upb.fielddef");
+ if (!f) luaL_typerror(L, narg, "upb fielddef");
+ return f;
+}
+
+static int lupb_fielddef_index(lua_State *L) {
+ lupb_fielddef *f = lupb_fielddef_check(L, 1);
+ const char *str = luaL_checkstring(L, 2);
+ if (streql(str, "name")) {
+ lua_pushstring(L, upb_fielddef_name(f->field));
+ } else if (streql(str, "number")) {
+ lua_pushinteger(L, upb_fielddef_number(f->field));
+ } else if (streql(str, "type")) {
+ lua_pushinteger(L, upb_fielddef_type(f->field));
+ } else if (streql(str, "label")) {
+ lua_pushinteger(L, upb_fielddef_label(f->field));
+ } else if (streql(str, "subdef")) {
+ lupb_def_getorcreate(L, upb_fielddef_subdef(f->field), false);
+ } else if (streql(str, "msgdef")) {
+ lupb_def_getorcreate(L, UPB_UPCAST(upb_fielddef_msgdef(f->field)), false);
+ } else {
+ luaL_error(L, "Invalid fielddef member '%s'", str);
+ }
+ return 1;
+}
+
+static void lupb_fielddef_set(lua_State *L, upb_fielddef *f,
+ const char *field, int narg) {
+ if (!upb_fielddef_ismutable(f)) luaL_error(L, "fielddef is not mutable.");
+ if (streql(field, "name")) {
+ const char *name = lua_tostring(L, narg);
+ if (!name || !upb_fielddef_setname(f, name))
+ luaL_error(L, "Invalid name");
+ } else if (streql(field, "number")) {
+ if (!upb_fielddef_setnumber(f, lupb_touint32(L, narg, "number")))
+ luaL_error(L, "Invalid number");
+ } else if (streql(field, "type")) {
+ if (!upb_fielddef_settype(f, lupb_touint8(L, narg, "type")))
+ luaL_error(L, "Invalid type");
+ } else if (streql(field, "label")) {
+ if (!upb_fielddef_setlabel(f, lupb_touint8(L, narg, "label")))
+ luaL_error(L, "Invalid label");
+ } else if (streql(field, "type_name")) {
+ const char *name = lua_tostring(L, narg);
+ if (!name || !upb_fielddef_settypename(f, name))
+ luaL_error(L, "Invalid type_name");
+ } else if (streql(field, "default_value")) {
+ if (!upb_fielddef_type(f))
+ luaL_error(L, "Must set type before setting default_value");
+ upb_strref ref;
+ upb_fielddef_setdefault(f, lupb_getvalue(L, narg, f, &ref));
+ } else {
+ luaL_error(L, "Cannot set fielddef member '%s'", field);
+ }
+}
+
+static int lupb_fielddef_new(lua_State *L) {
+ upb_fielddef *f = upb_fielddef_new();
+ lupb_cache_create(L, f, "upb.fielddef");
+
+ if (lua_gettop(L) == 0) return 1;
+
+ // User can specify initialization values like so:
+ // upb.FieldDef{label=upb.LABEL_REQUIRED, name="my_field", number=5,
+ // type=upb.TYPE_INT32, default_value=12, type_name="Foo"}
+ luaL_checktype(L, 1, LUA_TTABLE);
+ // Iterate over table.
+ lua_pushnil(L); // first key
+ while (lua_next(L, 1)) {
+ luaL_checktype(L, -2, LUA_TSTRING);
+ const char *key = lua_tostring(L, -2);
+ lupb_fielddef_set(L, f, key, -1);
+ lua_pop(L, 1);
+ }
+ return 1;
+}
+
+static void lupb_fielddef_getorcreate(lua_State *L, upb_fielddef *f) {
+ bool created = lupb_cache_getorcreate(L, f, "upb.fielddef");
+ if (created) upb_fielddef_ref(f);
+}
+
+static int lupb_fielddef_newindex(lua_State *L) {
+ lupb_fielddef *f = lupb_fielddef_check(L, 1);
+ lupb_fielddef_set(L, f->field, luaL_checkstring(L, 2), 3);
+ return 0;
+}
+
+static int lupb_fielddef_gc(lua_State *L) {
+ lupb_fielddef *lfielddef = lupb_fielddef_check(L, 1);
+ upb_fielddef_unref(lfielddef->field);
+ return 0;
+}
+
+static const struct luaL_Reg lupb_fielddef_mm[] = {
+ {"__gc", lupb_fielddef_gc},
+ {"__index", lupb_fielddef_index},
+ {"__newindex", lupb_fielddef_newindex},
+ {NULL, NULL}
+};
+
+
+/* lupb_msgdef ****************************************************************/
+
+static upb_msgdef *lupb_msgdef_check(lua_State *L, int narg) {
+ lupb_def *ldef = luaL_checkudata(L, narg, "upb.msgdef");
+ luaL_argcheck(L, ldef != NULL, narg, "upb msgdef expected");
+ return upb_downcast_msgdef(ldef->def);
+}
+
+static int lupb_msgdef_gc(lua_State *L) {
+ lupb_def *ldef = luaL_checkudata(L, 1, "upb.msgdef");
+ upb_def_unref(ldef->def);
+ return 0;
+}
+
+static int lupb_msgdef_call(lua_State *L) {
+ upb_msgdef *md = lupb_msgdef_check(L, 1);
+ lupb_msg_pushnew(L, md);
+ return 1;
+}
+
+static int lupb_msgdef_new(lua_State *L) {
+ upb_msgdef *md = upb_msgdef_new();
+ lupb_cache_create(L, md, "upb.msgdef");
+
+ if (lua_gettop(L) == 0) return 1;
+
+ // User can specify initialization values like so:
+ // upb.MessageDef{fqname="MyMessage", extstart=8000, fields={...}}
+ luaL_checktype(L, 1, LUA_TTABLE);
+ // Iterate over table.
+ lua_pushnil(L); // first key
+ while (lua_next(L, 1)) {
+ luaL_checktype(L, -2, LUA_TSTRING);
+ const char *key = lua_tostring(L, -2);
+
+ if (streql(key, "fqname")) { // fqname="MyMessage"
+ const char *fqname = lua_tostring(L, -1);
+ if (!fqname || !upb_def_setfqname(UPB_UPCAST(md), fqname))
+ luaL_error(L, "Invalid fqname");
+ } else if (streql(key, "fields")) { // fields={...}
+ // Iterate over the list of fields.
+ lua_pushnil(L);
+ luaL_checktype(L, -2, LUA_TTABLE);
+ while (lua_next(L, -2)) {
+ lupb_fielddef *f = lupb_fielddef_check(L, -1);
+ if (!upb_msgdef_addfield(md, f->field)) {
+ // TODO: more specific error.
+ luaL_error(L, "Could not add field.");
+ }
+ lua_pop(L, 1);
+ }
+ } else {
+ // TODO: extrange=
+ luaL_error(L, "Unknown initializer key '%s'", key);
+ }
+ lua_pop(L, 1);
+ }
+ return 1;
+}
+
+static int lupb_msgdef_fqname(lua_State *L) {
+ upb_msgdef *m = lupb_msgdef_check(L, 1);
+ lua_pushstring(L, m->base.fqname);
+ return 1;
+}
+
+static int lupb_msgdef_fieldbyname(lua_State *L) {
+ upb_msgdef *m = lupb_msgdef_check(L, 1);
+ upb_fielddef *f = upb_msgdef_ntof(m, luaL_checkstring(L, 2));
+ if (f) {
+ lupb_fielddef_getorcreate(L, f);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int lupb_msgdef_fieldbynum(lua_State *L) {
+ upb_msgdef *m = lupb_msgdef_check(L, 1);
+ int num = luaL_checkint(L, 2);
+ upb_fielddef *f = upb_msgdef_itof(m, num);
+ if (f) {
+ lupb_fielddef_getorcreate(L, f);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static const struct luaL_Reg lupb_msgdef_mm[] = {
+ {"__call", lupb_msgdef_call},
+ {"__gc", lupb_msgdef_gc},
+ {NULL, NULL}
+};
+
+static const struct luaL_Reg lupb_msgdef_m[] = {
+ {"fieldbyname", lupb_msgdef_fieldbyname},
+ {"fieldbynum", lupb_msgdef_fieldbynum},
+ {"fqname", lupb_msgdef_fqname},
+ {NULL, NULL}
+};
+
+
+/* lupb_enumdef ***************************************************************/
+
+static upb_enumdef *lupb_enumdef_check(lua_State *L, int narg) {
+ lupb_def *ldef = luaL_checkudata(L, narg, "upb.enumdef");
+ return upb_downcast_enumdef(ldef->def);
+}
+
+static int lupb_enumdef_gc(lua_State *L) {
+ upb_enumdef *e = lupb_enumdef_check(L, 1);
+ upb_def_unref(UPB_UPCAST(e));
+ return 0;
+}
+
+static int lupb_enumdef_name(lua_State *L) {
+ upb_enumdef *e = lupb_enumdef_check(L, 1);
+ lua_pushstring(L, e->base.fqname);
+ return 1;
+}
+
+static const struct luaL_Reg lupb_enumdef_mm[] = {
+ {"__gc", lupb_enumdef_gc},
+ {NULL, NULL}
+};
+
+static const struct luaL_Reg lupb_enumdef_m[] = {
+ {"name", lupb_enumdef_name},
+ {NULL, NULL}
+};
+
+
+/* lupb_symtab ****************************************************************/
+
+typedef struct {
+ upb_symtab *symtab;
+} lupb_symtab;
+
+static upb_accessor_vtbl *lupb_accessor(upb_fielddef *f);
+
+// Inherits a ref on the symtab.
+// Checks that narg is a proper lupb_symtab object. If it is, leaves its
+// metatable on the stack for cache lookups/updates.
+lupb_symtab *lupb_symtab_check(lua_State *L, int narg) {
+ return luaL_checkudata(L, narg, "upb.symtab");
+}
+
+// narg is a lua table containing a list of defs to add.
+void lupb_symtab_doadd(lua_State *L, upb_symtab *s, int narg) {
+ luaL_checktype(L, narg, LUA_TTABLE);
+ // Iterate over table twice. First iteration to count entries and
+ // check constraints.
+ int n = 0;
+ lua_pushnil(L); // first key
+ while (lua_next(L, narg)) {
+ lupb_def_check(L, -1);
+ ++n;
+ lua_pop(L, 1);
+ }
+
+ // Second iteration to build deflist and layout.
+ upb_def **defs = malloc(n * sizeof(*defs));
+ n = 0;
+ lua_pushnil(L); // first key
+ while (lua_next(L, 1)) {
+ upb_def *def = lupb_def_check(L, -1)->def;
+ defs[n++] = def;
+ upb_msgdef *md = upb_dyncast_msgdef(def);
+ if (md) {
+ upb_msg_iter i;
+ for(i = upb_msg_begin(md); !upb_msg_done(i); i = upb_msg_next(md, i)) {
+ upb_fielddef *f = upb_msg_iter_field(i);
+ upb_fielddef_setaccessor(f, lupb_accessor(f));
+ }
+ upb_msgdef_layout(md);
+ }
+ lua_pop(L, 1);
+ }
+
+ upb_status status = UPB_STATUS_INIT;
+ upb_symtab_add(s, defs, n, &status);
+ free(defs);
+ lupb_checkstatus(L, &status);
+}
+
+static int lupb_symtab_new(lua_State *L) {
+ upb_symtab *s = upb_symtab_new();
+ lupb_cache_create(L, s, "upb.symtab");
+ if (lua_gettop(L) == 0) return 1;
+ lupb_symtab_doadd(L, s, 1);
+ return 1;
+}
+
+static int lupb_symtab_add(lua_State *L) {
+ lupb_symtab *s = lupb_symtab_check(L, 1);
+ lupb_symtab_doadd(L, s->symtab, 2);
+ return 0;
+}
+
+static int lupb_symtab_gc(lua_State *L) {
+ lupb_symtab *s = lupb_symtab_check(L, 1);
+ upb_symtab_unref(s->symtab);
+ return 0;
+}
+
+static int lupb_symtab_lookup(lua_State *L) {
+ lupb_symtab *s = lupb_symtab_check(L, 1);
+ for (int i = 2; i <= lua_gettop(L); i++) {
+ upb_def *def = upb_symtab_lookup(s->symtab, luaL_checkstring(L, i));
+ if (def) {
+ lupb_def_getorcreate(L, def, true);
+ } else {
+ lua_pushnil(L);
+ }
+ lua_replace(L, i);
+ }
+ return lua_gettop(L) - 1;
+}
+
+static int lupb_symtab_getdefs(lua_State *L) {
+ lupb_symtab *s = lupb_symtab_check(L, 1);
+ upb_deftype_t type = luaL_checkint(L, 2);
+ int count;
+ upb_def **defs = upb_symtab_getdefs(s->symtab, &count, type);
+
+ // Create the table in which we will return the defs.
+ lua_createtable(L, count, 0);
+ for (int i = 0; i < count; i++) {
+ upb_def *def = defs[i];
+ lupb_def_getorcreate(L, def, true);
+ lua_rawseti(L, -2, i + 1);
+ }
+ free(defs);
+ return 1;
+}
+
+static const struct luaL_Reg lupb_symtab_m[] = {
+ {"add", lupb_symtab_add},
+ {"getdefs", lupb_symtab_getdefs},
+ {"lookup", lupb_symtab_lookup},
+ {NULL, NULL}
+};
+
+static const struct luaL_Reg lupb_symtab_mm[] = {
+ {"__gc", lupb_symtab_gc},
+ {NULL, NULL}
+};
+
+
+/* lupb_msg********************************************************************/
+
+// Messages are userdata. Primitive values (numbers and bools, and their
+// hasbits) are stored right in the userdata. Other values are stored using
+// integer entries in the environment table and no hasbits are used (since
+// "nil" in the environment table can indicate "not present").
+//
+// The environment table looks like:
+// {msgdef, <string, submessage, and array fields>}
+
+// Must pass a upb_fielddef as the pointer.
+static void lupb_array_pushnew(lua_State *L, void *f);
+
+static void *lupb_msg_check(lua_State *L, int narg, upb_msgdef **md) {
+ void *msg = luaL_checkudata(L, narg, "upb.msg");
+ luaL_argcheck(L, msg != NULL, narg, "msg expected");
+ // If going all the way to the environment table for the msgdef is an
+ // efficiency issue, we could put the pointer right in the userdata.
+ lua_getfenv(L, narg);
+ lua_rawgeti(L, -1, 1);
+ // Shouldn't have to check msgdef userdata validity, environment table can't
+ // be accessed from Lua.
+ lupb_def *lmd = lua_touserdata(L, -1);
+ *md = upb_downcast_msgdef(lmd->def);
+ return msg;
+}
+
+static void lupb_msg_pushnew(lua_State *L, void *md) {
+ void *msg = lua_newuserdata(L, upb_msgdef_size(md));
+ luaL_getmetatable(L, "upb.msg");
+ assert(!lua_isnil(L, -1)); // Should have been created by luaopen_upb.
+ lua_setmetatable(L, -2);
+ upb_msg_clear(msg, md);
+ lua_getfenv(L, -1);
+ lupb_cache_getorcreate(L, md, "upb.msgdef");
+ lua_rawseti(L, -2, 1);
+ lua_pop(L, 1); // Pop the fenv.
+}
+
+static int lupb_msg_new(lua_State *L) {
+ upb_msgdef *md = lupb_msgdef_check(L, 1);
+ lupb_msg_pushnew(L, md);
+ return 1;
+}
+
+static int lupb_msg_index(lua_State *L) {
+ upb_msgdef *md;
+ void *m = lupb_msg_check(L, 1, &md);
+ upb_fielddef *f = upb_msgdef_ntof(md, luaL_checkstring(L, 2));
+ if (!f) luaL_argerror(L, 2, "not a field name");
+ if (upb_isprimitivetype(upb_fielddef_type(f))) {
+ upb_value v = upb_msg_has(m, f) ? upb_msg_get(m, f) : upb_fielddef_default(f);
+ lupb_pushvalue(L, v, f);
+ } else {
+ lua_getfenv(L, 1);
+ lua_rawgeti(L, -1, f->offset);
+ if (lua_isnil(L, -1)) {
+ // Need to lazily create array, string, or submessage.
+ if (upb_isseq(f)) {
+ lupb_array_pushnew(L, f);
+ } else if (upb_isstring(f)) {
+ // TODO: (need to figure out default string ownership).
+ } else if (upb_issubmsg(f)) {
+ lupb_msg_pushnew(L, upb_downcast_msgdef(upb_fielddef_subdef(f)));
+ } else {
+ luaL_error(L, "internal error");
+ }
+ lua_rawseti(L, -2, f->offset);
+ }
+ }
+ return 1;
+}
+
+static int lupb_msg_newindex(lua_State *L) {
+ upb_msgdef *md;
+ void *m = lupb_msg_check(L, 1, &md);
+ upb_fielddef *f = upb_msgdef_ntof(md, luaL_checkstring(L, 2));
+ if (!f) luaL_error(L, "not a field name");
+ if (upb_isprimitivetype(upb_fielddef_type(f))) {
+ if (lua_isnil(L, 3))
+ upb_msg_clearbit(m, f);
+ else
+ upb_msg_set(m, f, lupb_getvalue(L, 3, f, NULL));
+ } else {
+ if (!lua_isnil(L, 3)) lupb_typecheck(L, 3, f);
+ lua_getfenv(L, 1);
+ lua_pushvalue(L, 3);
+ lua_rawseti(L, -1, f->offset);
+ }
+ return 0;
+}
+
+static const struct luaL_Reg lupb_msg_mm[] = {
+ {"__index", lupb_msg_index},
+ {"__newindex", lupb_msg_newindex},
+ {NULL, NULL}
+};
+
+// Functions that operate on msgdefs but do not live in the msgdef namespace.
+static int lupb_clear(lua_State *L) {
+ upb_msgdef *md;
+ void *m = lupb_msg_check(L, 1, &md);
+ upb_msg_clear(m, md);
+ return 0;
+}
+
+static int lupb_has(lua_State *L) {
+ upb_msgdef *md;
+ void *m = lupb_msg_check(L, 1, &md);
+ upb_fielddef *f = upb_msgdef_ntof(md, luaL_checkstring(L, 2));
+ if (!f) luaL_argerror(L, 2, "not a field name");
+ lua_pushboolean(L, upb_msg_has(m, f));
+ return 1;
+}
+
+static int lupb_msgdef(lua_State *L) {
+ upb_msgdef *md;
+ lupb_msg_check(L, 1, &md);
+ lupb_def_getorcreate(L, UPB_UPCAST(md), false);
+ return 1;
+}
+
+// Accessors for arrays, strings, and submessages need access to the current
+// userdata's environment table, which can only be stored in Lua space.
+// Options for storing it are:
+//
+// - put the env tables for all messages and arrays in the registry, keyed by
+// userdata pointer (light userdata), or by a reference using luaL_ref().
+// Then we can just let upb's parse stack track the stack of env tables.
+// Easy but requires all messages and arrays to be in the registry, which
+// seems too heavyweight.
+//
+// - store the stack of env tables in the Lua stack. Convenient, but requires
+// special code to handle resumable decoders.
+//
+// There is also the question of how to obtain the lua_State* pointer.
+// The main options for this are:
+//
+// - make our closure point to a struct:
+// struct { void *msg; lua_State *L; }
+// But then we can't use standard accessors, which expect the closure
+// to point to the data itself. Using the standard accessors for
+// primitive values is both a simplicity and a performance win.
+//
+// - store a lua_State* pointer inside each userdata. Convenient and
+// efficient, but makes every message sizeof(void*) larger.
+// Currently we take this route.
+//
+// - use thread-local storage. Convenient and efficient, but not portable.
+
+typedef void createfunc_t(lua_State *L, void *param);
+
+static upb_sflow_t lupb_msg_start(void *m, upb_fielddef *f, bool array,
+ createfunc_t *pushnew, void *param) {
+ lua_State *L = *(lua_State**)m;
+ int offset = array ? lua_rawlen(L, -1) : f->offset;
+ if (!lua_checkstack(L, 3)) luaL_error(L, "stack full");
+ lua_rawgeti(L, -1, offset);
+ if (lua_isnil(L, -1)) {
+ lua_pop(L, 1);
+ pushnew(L, param);
+ lua_pushvalue(L, -1);
+ lua_rawseti(L, -3, offset);
+ }
+ void *subval = lua_touserdata(L, -1);
+ lua_getfenv(L, -1);
+ lua_replace(L, -2); // Replace subval userdata with fenv.
+ return UPB_CONTINUE_WITH(subval);
+}
+
+static upb_flow_t lupb_msg_string(void *m, upb_value fval, upb_value val,
+ bool array) {
+ // Could add lazy materialization of strings here.
+ upb_fielddef *f = upb_value_getfielddef(fval);
+ lua_State *L = *(lua_State**)m;
+ int offset = array ? lua_rawlen(L, -1) : f->offset;
+ if (!lua_checkstack(L, 1)) luaL_error(L, "stack full");
+ lupb_pushstring(L, upb_value_getstrref(val));
+ lua_rawseti(L, -2, offset);
+ return UPB_CONTINUE;
+}
+
+static upb_sflow_t lupb_msg_startseq(void *m, upb_value fval) {
+ upb_fielddef *f = upb_value_getfielddef(fval);
+ return lupb_msg_start(m, f, false, lupb_array_pushnew, f);
+}
+
+static upb_sflow_t lupb_msg_startsubmsg(void *m, upb_value fval) {
+ upb_fielddef *f = upb_value_getfielddef(fval);
+ return lupb_msg_start(m, f, false, lupb_msg_pushnew, upb_fielddef_subdef(f));
+}
+
+static upb_sflow_t lupb_msg_startsubmsg_r(void *a, upb_value fval) {
+ upb_fielddef *f = upb_value_getfielddef(fval);
+ return lupb_msg_start(a, f, true, lupb_msg_pushnew, upb_fielddef_subdef(f));
+}
+
+static upb_flow_t lupb_msg_stringval(void *m, upb_value fval, upb_value val) {
+ return lupb_msg_string(m, fval, val, false);
+}
+
+static upb_flow_t lupb_msg_stringval_r(void *a, upb_value fval, upb_value val) {
+ return lupb_msg_string(a, fval, val, true);
+}
+
+#define STDMSG(type, size) static upb_accessor_vtbl vtbl = { \
+ &lupb_msg_startsubmsg, \
+ &upb_stdmsg_set ## type, \
+ &lupb_msg_startseq, \
+ &lupb_msg_startsubmsg_r, \
+ &upb_stdmsg_set ## type ## _r, \
+ &upb_stdmsg_has, \
+ &upb_stdmsg_getptr, \
+ &upb_stdmsg_get ## type, \
+ &upb_stdmsg_seqbegin, \
+ &upb_stdmsg_ ## size ## byte_seqnext, \
+ &upb_stdmsg_seqget ## type};
+
+#define RETURN_STDMSG(type, size) { STDMSG(type, size); return &vtbl; }
+
+static upb_accessor_vtbl *lupb_accessor(upb_fielddef *f) {
+ switch (f->type) {
+ case UPB_TYPE(DOUBLE): RETURN_STDMSG(double, 8)
+ case UPB_TYPE(FLOAT): RETURN_STDMSG(float, 4)
+ case UPB_TYPE(UINT64):
+ case UPB_TYPE(FIXED64): RETURN_STDMSG(uint64, 8)
+ case UPB_TYPE(INT64):
+ case UPB_TYPE(SFIXED64):
+ case UPB_TYPE(SINT64): RETURN_STDMSG(int64, 8)
+ case UPB_TYPE(INT32):
+ case UPB_TYPE(SINT32):
+ case UPB_TYPE(ENUM):
+ case UPB_TYPE(SFIXED32): RETURN_STDMSG(int32, 4)
+ case UPB_TYPE(UINT32):
+ case UPB_TYPE(FIXED32): RETURN_STDMSG(uint32, 4)
+ case UPB_TYPE(BOOL): { STDMSG(bool, 1); return &vtbl; }
+ case UPB_TYPE(GROUP):
+ case UPB_TYPE(MESSAGE): RETURN_STDMSG(ptr, 8) // TODO: 32-bit
+ case UPB_TYPE(STRING):
+ case UPB_TYPE(BYTES): {
+ STDMSG(ptr, 8);
+ vtbl.set = &lupb_msg_stringval;
+ vtbl.append = &lupb_msg_stringval_r;
+ return &vtbl;
+ }
+ }
+ return NULL;
+}
+
+
+/* lupb_array ****************************************************************/
+
+// Array: we store all elements in the environment table. Could optimize by
+// storing primitive arrays in our own memory; this would be significantly more
+// space efficient. Lua array elements are 16 bytes each; our own array would
+// be 1/4 the space for 32-bit integers, or 1/16 the space for booleans.
+//
+// The first element of the environment table stores our type (which will be
+// either an integer from upb.TYPE_* or a upb.msgdef), the remaining elements
+// store the elements. We always keep all elements contiguous so we can use
+// lua_objlen()/lua_rawlen() (for Lua 5.1/5.2 respectively) to report its len).
+
+// narg is offset of environment table.
+static size_t lupb_array_getlen(lua_State *L, int narg) {
+ return lua_rawlen(L, narg) - 1;
+}
+
+static void lupb_array_check(lua_State *L, int narg) {
+ if (!luaL_checkudata(L, narg, "upb.array"))
+ luaL_typerror(L, narg, "upb array");
+}
+
+static void lupb_array_pushnew(lua_State *L, void *f) {
+ (void)L;
+ (void)f;
+}
+
+static int lupb_array_new(lua_State *L) {
+ (void)L;
+ return 0;
+}
+
+static int lupb_array_len(lua_State *L) {
+ lupb_array_check(L, 1);
+ lua_getfenv(L, 1);
+ lua_pushnumber(L, lupb_array_getlen(L, -1));
+ return 1;
+}
+
+static int lupb_array_index(lua_State *L) {
+ assert(lua_gettop(L) == 2); // __index should always be called with 2 args.
+ lupb_array_check(L, 1);
+ lua_Number num = luaL_checknumber(L, 2);
+ if (!lupb_isint(num)) luaL_typerror(L, 2, "integer");
+
+ lua_getfenv(L, 1);
+ size_t len = lupb_array_getlen(L, -1);
+ if (num < 1 || num > len) luaL_error(L, "array bounds check failed");
+ lua_rawgeti(L, -1, num + 1);
+ return 1;
+}
+
+static int lupb_array_newindex(lua_State *L) {
+ assert(lua_gettop(L) == 3); // __newindex should always be called with 3 args.
+ lupb_array_check(L, 1);
+ lua_Number num = luaL_checknumber(L, 2);
+ if (rint(num) != num) luaL_typerror(L, 2, "integer");
+
+ lua_getfenv(L, 1);
+ size_t len = lupb_array_getlen(L, -1);
+ // We only allow extending the index one beyond the end.
+ if (num < 1 || num > len + 1) luaL_error(L, "array bounds check failed");
+ lua_pushvalue(L, 3);
+ lua_rawseti(L, -2, num);
+ return 0;
+}
+
+static const struct luaL_Reg lupb_array_mm[] = {
+ {"__len", lupb_array_len},
+ {"__index", lupb_array_index},
+ {"__newindex", lupb_array_newindex},
+ {NULL, NULL}
+};
+
+/* lupb toplevel **************************************************************/
+
+static const struct luaL_Reg lupb_toplevel_m[] = {
+ {"SymbolTable", lupb_symtab_new},
+ {"MessageDef", lupb_msgdef_new},
+ {"FieldDef", lupb_fielddef_new},
+
+ {"Message", lupb_msg_new},
+ {"Array", lupb_array_new},
+
+ {"clear", lupb_clear},
+ {"msgdef", lupb_msgdef},
+ {"has", lupb_has},
+
+ {NULL, NULL}
+};
+
+// Register the given type with the given methods and metamethods.
+static void lupb_register_type(lua_State *L, const char *name,
+ const luaL_Reg *m, const luaL_Reg *mm) {
+ luaL_newmetatable(L, name);
+ luaL_register(L, NULL, mm); // Register all mm in the metatable.
+ lua_createtable(L, 0, 0);
+ if (m) {
+ // Methods go in the mt's __index method. This implies that you can't
+ // implement __index and also set methods yourself.
+ luaL_register(L, NULL, m);
+ lua_setfield(L, -2, "__index");
+ }
+ lua_pop(L, 1); // The mt.
+}
+
+static void lupb_setfieldi(lua_State *L, const char *field, int i) {
+ lua_pushnumber(L, i);
+ lua_setfield(L, -2, field);
+}
+
+int luaopen_upb(lua_State *L) {
+ lupb_register_type(L, "upb.msgdef", lupb_msgdef_m, lupb_msgdef_mm);
+ lupb_register_type(L, "upb.enumdef", lupb_enumdef_m, lupb_enumdef_mm);
+ lupb_register_type(L, "upb.fielddef", NULL, lupb_fielddef_mm);
+ lupb_register_type(L, "upb.symtab", lupb_symtab_m, lupb_symtab_mm);
+
+ lupb_register_type(L, "upb.msg", NULL, lupb_msg_mm);
+ lupb_register_type(L, "upb.array", NULL, lupb_msg_mm);
+
+ // Create our object cache.
+ lua_createtable(L, 0, 0);
+ lua_createtable(L, 0, 1); // Cache metatable.
+ lua_pushstring(L, "v"); // Values are weak.
+ lua_setfield(L, -2, "__mode");
+ lua_setfield(L, LUA_REGISTRYINDEX, "upb.objcache");
+
+ luaL_register(L, "upb", lupb_toplevel_m);
+
+ // Register constants.
+ lupb_setfieldi(L, "LABEL_OPTIONAL", UPB_LABEL(OPTIONAL));
+ lupb_setfieldi(L, "LABEL_REQUIRED", UPB_LABEL(REQUIRED));
+ lupb_setfieldi(L, "LABEL_REPEATED", UPB_LABEL(REPEATED));
+
+ lupb_setfieldi(L, "TYPE_DOUBLE", UPB_TYPE(DOUBLE));
+ lupb_setfieldi(L, "TYPE_FLOAT", UPB_TYPE(FLOAT));
+ lupb_setfieldi(L, "TYPE_INT64", UPB_TYPE(INT64));
+ lupb_setfieldi(L, "TYPE_UINT64", UPB_TYPE(UINT64));
+ lupb_setfieldi(L, "TYPE_INT32", UPB_TYPE(INT32));
+ lupb_setfieldi(L, "TYPE_FIXED64", UPB_TYPE(FIXED64));
+ lupb_setfieldi(L, "TYPE_FIXED32", UPB_TYPE(FIXED32));
+ lupb_setfieldi(L, "TYPE_BOOL", UPB_TYPE(BOOL));
+ lupb_setfieldi(L, "TYPE_STRING", UPB_TYPE(STRING));
+ lupb_setfieldi(L, "TYPE_GROUP", UPB_TYPE(GROUP));
+ lupb_setfieldi(L, "TYPE_MESSAGE", UPB_TYPE(MESSAGE));
+ lupb_setfieldi(L, "TYPE_BYTES", UPB_TYPE(BYTES));
+ lupb_setfieldi(L, "TYPE_UINT32", UPB_TYPE(UINT32));
+ lupb_setfieldi(L, "TYPE_ENUM", UPB_TYPE(ENUM));
+ lupb_setfieldi(L, "TYPE_SFIXED32", UPB_TYPE(SFIXED32));
+ lupb_setfieldi(L, "TYPE_SFIXED64", UPB_TYPE(SFIXED64));
+ lupb_setfieldi(L, "TYPE_SINT32", UPB_TYPE(SINT32));
+ lupb_setfieldi(L, "TYPE_SINT64", UPB_TYPE(SINT64));
+
+ return 1; // Return package table.
+}
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