diff options
Diffstat (limited to 'xpcom/reflect/xptinfo/xptcodegen.py')
| -rw-r--r-- | xpcom/reflect/xptinfo/xptcodegen.py | 646 |
1 files changed, 646 insertions, 0 deletions
diff --git a/xpcom/reflect/xptinfo/xptcodegen.py b/xpcom/reflect/xptinfo/xptcodegen.py new file mode 100644 index 0000000000..34131f6678 --- /dev/null +++ b/xpcom/reflect/xptinfo/xptcodegen.py @@ -0,0 +1,646 @@ +#!/usr/bin/env python +# jsonlink.py - Merge JSON typelib files into a .cpp file +# +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, You can obtain one at http://mozilla.org/MPL/2.0/. + +import json +from collections import OrderedDict + +import buildconfig +from perfecthash import PerfectHash + +# Pick a nice power-of-two size for our intermediate PHF tables. +PHFSIZE = 512 + + +def indented(s): + return s.replace("\n", "\n ") + + +def cpp(v): + if type(v) == bool: + return "true" if v else "false" + return str(v) + + +def mkstruct(*fields): + def mk(comment, **vals): + assert len(fields) == len(vals) + r = "{ // " + comment + r += indented(",".join("\n/* %s */ %s" % (k, cpp(vals[k])) for k in fields)) + r += "\n}" + return r + + return mk + + +########################################################## +# Ensure these fields are in the same order as xptinfo.h # +########################################################## +nsXPTInterfaceInfo = mkstruct( + "mIID", + "mName", + "mParent", + "mBuiltinClass", + "mMainProcessScriptableOnly", + "mMethods", + "mConsts", + "mFunction", + "mNumMethods", + "mNumConsts", +) + +########################################################## +# Ensure these fields are in the same order as xptinfo.h # +########################################################## +nsXPTType = mkstruct( + "mTag", + "mInParam", + "mOutParam", + "mOptionalParam", + "mData1", + "mData2", +) + +########################################################## +# Ensure these fields are in the same order as xptinfo.h # +########################################################## +nsXPTParamInfo = mkstruct( + "mType", +) + +########################################################## +# Ensure these fields are in the same order as xptinfo.h # +########################################################## +nsXPTMethodInfo = mkstruct( + "mName", + "mParams", + "mNumParams", + "mGetter", + "mSetter", + "mReflectable", + "mOptArgc", + "mContext", + "mHasRetval", + "mIsSymbol", +) + +########################################################## +# Ensure these fields are in the same order as xptinfo.h # +########################################################## +nsXPTDOMObjectInfo = mkstruct( + "mUnwrap", + "mWrap", + "mCleanup", +) + +########################################################## +# Ensure these fields are in the same order as xptinfo.h # +########################################################## +nsXPTConstantInfo = mkstruct( + "mName", + "mSigned", + "mValue", +) + + +# Helper functions for dealing with IIDs. +# +# Unfortunately, the way we represent IIDs in memory depends on the endianness +# of the target architecture. We store an nsIID as a 16-byte, 4-tuple of: +# +# (uint32_t, uint16_t, uint16_t, [uint8_t; 8]) +# +# Unfortunately, this means that when we hash the bytes of the nsIID on a +# little-endian target system, we need to hash them in little-endian order. +# These functions let us split the input hexadecimal string into components, +# encoding each as a little-endian value, and producing an accurate bytearray. +# +# It would be nice to have a consistent representation of IIDs in memory such +# that we don't have to do these gymnastics to get an accurate hash. + + +def split_at_idxs(s, lengths): + idx = 0 + for length in lengths: + yield s[idx : idx + length] + idx += length + assert idx == len(s) + + +def split_iid(iid): # Get the individual components out of an IID string. + iid = iid.replace("-", "") # Strip any '-' delimiters + return tuple(split_at_idxs(iid, (8, 4, 4, 2, 2, 2, 2, 2, 2, 2, 2))) + + +def iid_bytes(iid): # Get the byte representation of the IID for hashing. + bs = bytearray() + for num in split_iid(iid): + b = bytearray.fromhex(num) + # Match endianness of the target platform for each component + if buildconfig.substs["TARGET_ENDIANNESS"] == "little": + b.reverse() + bs += b + return bs + + +# Split a 16-bit integer into its high and low 8 bits +def splitint(i): + assert i < 2 ** 16 + return (i >> 8, i & 0xFF) + + +# Occasionally in xpconnect, we need to fabricate types to pass into the +# conversion methods. In some cases, these types need to be arrays, which hold +# indicies into the extra types array. +# +# These are some types which should have known indexes into the extra types +# array. +utility_types = [ + {"tag": "TD_INT8"}, + {"tag": "TD_UINT8"}, + {"tag": "TD_INT16"}, + {"tag": "TD_UINT16"}, + {"tag": "TD_INT32"}, + {"tag": "TD_UINT32"}, + {"tag": "TD_INT64"}, + {"tag": "TD_UINT64"}, + {"tag": "TD_FLOAT"}, + {"tag": "TD_DOUBLE"}, + {"tag": "TD_BOOL"}, + {"tag": "TD_CHAR"}, + {"tag": "TD_WCHAR"}, + {"tag": "TD_NSIDPTR"}, + {"tag": "TD_PSTRING"}, + {"tag": "TD_PWSTRING"}, + {"tag": "TD_INTERFACE_IS_TYPE", "iid_is": 0}, +] + + +# Core of the code generator. Takes a list of raw JSON XPT interfaces, and +# writes out a file containing the necessary static declarations into fd. +def link_to_cpp(interfaces, fd, header_fd): + # Perfect Hash from IID to interface. + iid_phf = PerfectHash(interfaces, PHFSIZE, key=lambda i: iid_bytes(i["uuid"])) + for idx, iface in enumerate(iid_phf.entries): + iface["idx"] = idx # Store the index in iid_phf of the entry. + + # Perfect Hash from name to iid_phf index. + name_phf = PerfectHash(interfaces, PHFSIZE, key=lambda i: i["name"].encode("ascii")) + + def interface_idx(name): + entry = name and name_phf.get_entry(name.encode("ascii")) + if entry: + return entry["idx"] + 1 # 1-based, use 0 as a sentinel. + return 0 + + # NOTE: State used while linking. This is done with closures rather than a + # class due to how this file's code evolved. + includes = set() + types = [] + type_cache = {} + params = [] + param_cache = {} + methods = [] + max_params = 0 + method_with_max_params = None + consts = [] + domobjects = [] + domobject_cache = {} + strings = OrderedDict() + + def lower_uuid(uuid): + return ( + "{0x%s, 0x%s, 0x%s, {0x%s, 0x%s, 0x%s, 0x%s, 0x%s, 0x%s, 0x%s, 0x%s}}" + % split_iid(uuid) + ) + + def lower_domobject(do): + assert do["tag"] == "TD_DOMOBJECT" + + idx = domobject_cache.get(do["name"]) + if idx is None: + idx = domobject_cache[do["name"]] = len(domobjects) + + includes.add(do["headerFile"]) + domobjects.append( + nsXPTDOMObjectInfo( + "%d = %s" % (idx, do["name"]), + # These methods are defined at the top of the generated file. + mUnwrap="UnwrapDOMObject<mozilla::dom::prototypes::id::%s, %s>" + % (do["name"], do["native"]), + mWrap="WrapDOMObject<%s>" % do["native"], + mCleanup="CleanupDOMObject<%s>" % do["native"], + ) + ) + + return idx + + def lower_string(s): + if s in strings: + # We've already seen this string. + return strings[s] + elif len(strings): + # Get the last string we inserted (should be O(1) on OrderedDict). + last_s = next(reversed(strings)) + strings[s] = strings[last_s] + len(last_s) + 1 + else: + strings[s] = 0 + return strings[s] + + def lower_symbol(s): + return "uint32_t(JS::SymbolCode::%s)" % s + + def lower_extra_type(type): + key = describe_type(type) + idx = type_cache.get(key) + if idx is None: + idx = type_cache[key] = len(types) + # Make sure `types` is the proper length for any recursive calls + # to `lower_extra_type` that might happen from within `lower_type`. + types.append(None) + realtype = lower_type(type) + types[idx] = realtype + return idx + + def describe_type(type): # Create the type's documentation comment. + tag = type["tag"][3:].lower() + if tag == "legacy_array": + return "%s[size_is=%d]" % (describe_type(type["element"]), type["size_is"]) + elif tag == "array": + return "Array<%s>" % describe_type(type["element"]) + elif tag == "interface_type" or tag == "domobject": + return type["name"] + elif tag == "interface_is_type": + return "iid_is(%d)" % type["iid_is"] + elif tag.endswith("_size_is"): + return "%s(size_is=%d)" % (tag, type["size_is"]) + return tag + + def lower_type(type, in_=False, out=False, optional=False): + tag = type["tag"] + d1 = d2 = 0 + + # TD_VOID is used for types that can't be represented in JS, so they + # should not be represented in the XPT info. + assert tag != "TD_VOID" + + if tag == "TD_LEGACY_ARRAY": + d1 = type["size_is"] + d2 = lower_extra_type(type["element"]) + + elif tag == "TD_ARRAY": + # NOTE: TD_ARRAY can hold 16 bits of type index, while + # TD_LEGACY_ARRAY can only hold 8. + d1, d2 = splitint(lower_extra_type(type["element"])) + + elif tag == "TD_INTERFACE_TYPE": + d1, d2 = splitint(interface_idx(type["name"])) + + elif tag == "TD_INTERFACE_IS_TYPE": + d1 = type["iid_is"] + + elif tag == "TD_DOMOBJECT": + d1, d2 = splitint(lower_domobject(type)) + + elif tag.endswith("_SIZE_IS"): + d1 = type["size_is"] + + assert d1 < 256 and d2 < 256, "Data values too large" + return nsXPTType( + describe_type(type), + mTag=tag, + mData1=d1, + mData2=d2, + mInParam=in_, + mOutParam=out, + mOptionalParam=optional, + ) + + def lower_param(param, paramname): + params.append( + nsXPTParamInfo( + "%d = %s" % (len(params), paramname), + mType=lower_type( + param["type"], + in_="in" in param["flags"], + out="out" in param["flags"], + optional="optional" in param["flags"], + ), + ) + ) + + def is_type_reflectable(type): + # All native types end up getting tagged as void*, or as wrapper types around void* + if type["tag"] == "TD_VOID": + return False + if type["tag"] in ("TD_ARRAY", "TD_LEGACY_ARRAY"): + return is_type_reflectable(type["element"]) + return True + + def is_method_reflectable(method): + if "hidden" in method["flags"]: + return False + + for param in method["params"]: + # Reflected methods can't use non-reflectable types. + if not is_type_reflectable(param["type"]): + return False + + return True + + def lower_method(method, ifacename): + methodname = "%s::%s" % (ifacename, method["name"]) + + isSymbol = "symbol" in method["flags"] + reflectable = is_method_reflectable(method) + + if not reflectable: + # Hide the parameters of methods that can't be called from JS to + # reduce the size of the file. + paramidx = name = numparams = 0 + else: + if isSymbol: + name = lower_symbol(method["name"]) + else: + name = lower_string(method["name"]) + + numparams = len(method["params"]) + + # Check cache for parameters + cachekey = json.dumps(method["params"], sort_keys=True) + paramidx = param_cache.get(cachekey) + if paramidx is None: + paramidx = param_cache[cachekey] = len(params) + for idx, param in enumerate(method["params"]): + lower_param(param, "%s[%d]" % (methodname, idx)) + + nonlocal max_params, method_with_max_params + if numparams > max_params: + max_params = numparams + method_with_max_params = methodname + methods.append( + nsXPTMethodInfo( + "%d = %s" % (len(methods), methodname), + mName=name, + mParams=paramidx, + mNumParams=numparams, + # Flags + mGetter="getter" in method["flags"], + mSetter="setter" in method["flags"], + mReflectable=reflectable, + mOptArgc="optargc" in method["flags"], + mContext="jscontext" in method["flags"], + mHasRetval="hasretval" in method["flags"], + mIsSymbol=isSymbol, + ) + ) + + def lower_const(const, ifacename): + assert const["type"]["tag"] in [ + "TD_INT16", + "TD_INT32", + "TD_UINT8", + "TD_UINT16", + "TD_UINT32", + ] + is_signed = const["type"]["tag"] in ["TD_INT16", "TD_INT32"] + + # Constants are always either signed or unsigned 16 or 32 bit integers, + # which we will only need to convert to JS values. To save on space, + # don't bother storing the type, and instead just store a 32-bit + # unsigned integer, and stash whether to interpret it as signed. + consts.append( + nsXPTConstantInfo( + "%d = %s::%s" % (len(consts), ifacename, const["name"]), + mName=lower_string(const["name"]), + mSigned=is_signed, + mValue="(uint32_t)%d" % const["value"], + ) + ) + + def ancestors(iface): + yield iface + while iface["parent"]: + iface = name_phf.get_entry(iface["parent"].encode("ascii")) + yield iface + + def lower_iface(iface): + method_cnt = sum(len(i["methods"]) for i in ancestors(iface)) + const_cnt = sum(len(i["consts"]) for i in ancestors(iface)) + + # The number of maximum methods is not arbitrary. It is the same value + # as in xpcom/reflect/xptcall/genstubs.pl; do not change this value + # without changing that one or you WILL see problems. + # + # In addition, mNumMethods and mNumConsts are stored as a 8-bit ints, + # meaning we cannot exceed 255 methods/consts on any interface. + assert method_cnt < 250, "%s has too many methods" % iface["name"] + assert const_cnt < 256, "%s has too many constants" % iface["name"] + + # Store the lowered interface as 'cxx' on the iface object. + iface["cxx"] = nsXPTInterfaceInfo( + "%d = %s" % (iface["idx"], iface["name"]), + mIID=lower_uuid(iface["uuid"]), + mName=lower_string(iface["name"]), + mParent=interface_idx(iface["parent"]), + mMethods=len(methods), + mNumMethods=method_cnt, + mConsts=len(consts), + mNumConsts=const_cnt, + # Flags + mBuiltinClass="builtinclass" in iface["flags"], + mMainProcessScriptableOnly="main_process_only" in iface["flags"], + mFunction="function" in iface["flags"], + ) + + # Lower methods and constants used by this interface + for method in iface["methods"]: + lower_method(method, iface["name"]) + for const in iface["consts"]: + lower_const(const, iface["name"]) + + # Lower the types which have fixed indexes first, and check that the indexes + # seem correct. + for expected, ty in enumerate(utility_types): + got = lower_extra_type(ty) + assert got == expected, "Wrong index when lowering" + + # Lower interfaces in the order of the IID phf's entries lookup. + for iface in iid_phf.entries: + lower_iface(iface) + + # Write out the final output files + fd.write("/* THIS FILE WAS GENERATED BY xptcodegen.py - DO NOT EDIT */\n\n") + header_fd.write("/* THIS FILE WAS GENERATED BY xptcodegen.py - DO NOT EDIT */\n\n") + + header_fd.write( + """ +#ifndef xptdata_h +#define xptdata_h + +enum class nsXPTInterface : uint16_t { +""" + ) + + for entry in iid_phf.entries: + header_fd.write(" %s,\n" % entry["name"]) + + header_fd.write( + """ +}; + +#endif +""" + ) + + # Include any bindings files which we need to include for webidl types + for include in sorted(includes): + fd.write('#include "%s"\n' % include) + + # Write out our header + fd.write( + """ +#include "xptinfo.h" +#include "mozilla/PerfectHash.h" +#include "mozilla/dom/BindingUtils.h" + +// These template methods are specialized to be used in the sDOMObjects table. +template<mozilla::dom::prototypes::ID PrototypeID, typename T> +static nsresult UnwrapDOMObject(JS::Handle<JS::Value> aHandle, void** aObj, JSContext* aCx) +{ + RefPtr<T> p; + nsresult rv = mozilla::dom::UnwrapObject<PrototypeID, T>(aHandle, p, aCx); + p.forget(aObj); + return rv; +} + +template<typename T> +static bool WrapDOMObject(JSContext* aCx, void* aObj, JS::MutableHandle<JS::Value> aHandle) +{ + return mozilla::dom::GetOrCreateDOMReflector(aCx, reinterpret_cast<T*>(aObj), aHandle); +} + +template<typename T> +static void CleanupDOMObject(void* aObj) +{ + RefPtr<T> p = already_AddRefed<T>(reinterpret_cast<T*>(aObj)); +} + +namespace xpt { +namespace detail { + +""" + ) + + # Static data arrays + def array(ty, name, els): + fd.write( + "const %s %s[] = {%s\n};\n\n" + % (ty, name, ",".join(indented("\n" + str(e)) for e in els)) + ) + + array("nsXPTType", "sTypes", types) + array("nsXPTParamInfo", "sParams", params) + array("nsXPTMethodInfo", "sMethods", methods) + # Verify that stack-allocated buffers will do for xptcall implementations. + msg = ( + "Too many method arguments in %s. " + "Either reduce the number of arguments " + "or increase PARAM_BUFFER_COUNT." % method_with_max_params + ) + fd.write('static_assert(%s <= PARAM_BUFFER_COUNT, "%s");\n\n' % (max_params, msg)) + array("nsXPTDOMObjectInfo", "sDOMObjects", domobjects) + array("nsXPTConstantInfo", "sConsts", consts) + + # The strings array. We write out individual characters to avoid MSVC restrictions. + fd.write("const char sStrings[] = {\n") + for s, off in strings.items(): + fd.write(" // %d = %s\n '%s','\\0',\n" % (off, s, "','".join(s))) + fd.write("};\n\n") + + # Build the perfect hash table for InterfaceByIID + fd.write( + iid_phf.cxx_codegen( + name="InterfaceByIID", + entry_type="nsXPTInterfaceInfo", + entries_name="sInterfaces", + lower_entry=lambda iface: iface["cxx"], + # Check that the IIDs match to support IID keys not in the map. + return_type="const nsXPTInterfaceInfo*", + return_entry="return entry.IID().Equals(aKey) ? &entry : nullptr;", + key_type="const nsIID&", + key_bytes="reinterpret_cast<const char*>(&aKey)", + key_length="sizeof(nsIID)", + ) + ) + fd.write("\n") + + # Build the perfect hash table for InterfaceByName + fd.write( + name_phf.cxx_codegen( + name="InterfaceByName", + entry_type="uint16_t", + lower_entry=lambda iface: "%-4d /* %s */" % (iface["idx"], iface["name"]), + # Get the actual nsXPTInterfaceInfo from sInterfaces, and + # double-check that names match. + return_type="const nsXPTInterfaceInfo*", + return_entry="return strcmp(sInterfaces[entry].Name(), aKey) == 0" + " ? &sInterfaces[entry] : nullptr;", + ) + ) + fd.write("\n") + + # Generate some checks that the indexes for the utility types match the + # declared ones in xptinfo.h + for idx, ty in enumerate(utility_types): + fd.write( + 'static_assert(%d == (uint8_t)nsXPTType::Idx::%s, "Bad idx");\n' + % (idx, ty["tag"][3:]) + ) + + fd.write( + """ +const uint16_t sInterfacesSize = mozilla::ArrayLength(sInterfaces); + +} // namespace detail +} // namespace xpt +""" + ) + + +def link_and_write(files, outfile, outheader): + interfaces = [] + for file in files: + with open(file, "r") as fd: + interfaces += json.load(fd) + + iids = set() + names = set() + for interface in interfaces: + assert interface["uuid"] not in iids, "duplicated UUID %s" % interface["uuid"] + assert interface["name"] not in names, "duplicated name %s" % interface["name"] + iids.add(interface["uuid"]) + names.add(interface["name"]) + + link_to_cpp(interfaces, outfile, outheader) + + +def main(): + import sys + from argparse import ArgumentParser + + parser = ArgumentParser() + parser.add_argument("outfile", help="Output C++ file to generate") + parser.add_argument("outheader", help="Output C++ header file to generate") + parser.add_argument("xpts", nargs="*", help="source xpt files") + + args = parser.parse_args(sys.argv[1:]) + with open(args.outfile, "w") as fd, open(args.outheader, "w") as header_fd: + link_and_write(args.xpts, fd, header_fd) + + +if __name__ == "__main__": + main() |