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-rw-r--r--xpcom/reflect/xptinfo/xptcodegen.py646
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
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--- /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()