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#!/usr/bin/env python
# header.py - Generate C++ header files from IDL.
#
# 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
"""Print a C++ header file for the IDL files specified on the command line"""
import itertools
import os.path
import re
from xpidl import xpidl
printdoccomments = False
if printdoccomments:
def printComments(fd, clist, indent):
for c in clist:
fd.write("%s%s\n" % (indent, c))
else:
def printComments(fd, clist, indent):
pass
def firstCap(str):
return str[0].upper() + str[1:]
def attributeParamName(a):
return "a" + firstCap(a.name)
def attributeParamNames(a, getter, return_param=True):
if getter and (a.notxpcom or not return_param):
l = []
else:
l = [attributeParamName(a)]
if a.implicit_jscontext:
l.insert(0, "cx")
return ", ".join(l)
def attributeNativeName(a, getter):
binaryname = a.binaryname is not None and a.binaryname or firstCap(a.name)
return "%s%s" % (getter and "Get" or "Set", binaryname)
def attributeAttributes(a, getter):
ret = ""
if a.must_use:
ret = "[[nodiscard]] " + ret
# Ideally, we'd set MOZ_CAN_RUN_SCRIPT in the "scriptable and not
# builtinclass" case too, so we'd just have memberCanRunScript() check
# explicit_setter_can_run_script/explicit_setter_can_run_script and call it
# here. But that would likely require a fair amount of Gecko-side
if (a.explicit_getter_can_run_script and getter) or (
a.explicit_setter_can_run_script and not getter
):
ret = "MOZ_CAN_RUN_SCRIPT " + ret
return ret
def attributeReturnType(a, getter, macro):
"""macro should be NS_IMETHOD or NS_IMETHODIMP"""
# Pick the type to be returned from the getter/setter.
if a.notxpcom:
ret = a.realtype.nativeType("in").strip() if getter else "void"
else:
ret = "nsresult"
# Set calling convention and virtual-ness
if a.nostdcall:
if macro == "NS_IMETHOD":
# This is the declaration.
ret = "virtual %s" % ret
else:
if ret == "nsresult":
ret = macro
else:
ret = "%s_(%s)" % (macro, ret)
return attributeAttributes(a, getter) + ret
def attributeParamlist(a, getter, return_param=True):
if getter and (a.notxpcom or not return_param):
l = []
else:
l = [
"%s%s"
% (a.realtype.nativeType(getter and "out" or "in"), attributeParamName(a))
]
if a.implicit_jscontext:
l.insert(0, "JSContext* cx")
return ", ".join(l)
def attributeAsNative(a, getter, declType="NS_IMETHOD"):
params = {
"returntype": attributeReturnType(a, getter, declType),
"binaryname": attributeNativeName(a, getter),
"paramlist": attributeParamlist(a, getter),
}
return "%(returntype)s %(binaryname)s(%(paramlist)s)" % params
def methodNativeName(m):
return m.binaryname is not None and m.binaryname or firstCap(m.name)
def methodAttributes(m):
ret = ""
if m.must_use:
ret = "[[nodiscard]] " + ret
# Ideally, we'd set MOZ_CAN_RUN_SCRIPT in the "scriptable and not
# builtinclass" case too, so we'd just have memberCanRunScript() check
# explicit_can_run_script and call it here. But that would likely require
if m.explicit_can_run_script:
ret = "MOZ_CAN_RUN_SCRIPT " + ret
return ret
def methodReturnType(m, macro):
"""macro should be NS_IMETHOD or NS_IMETHODIMP"""
if m.notxpcom:
ret = m.realtype.nativeType("in").strip()
else:
ret = "nsresult"
# Set calling convention and virtual-ness
if m.nostdcall:
if macro == "NS_IMETHOD":
# This is the declaration
ret = "virtual %s" % ret
else:
if ret == "nsresult":
ret = macro
else:
ret = "%s_(%s)" % (macro, ret)
return methodAttributes(m) + ret
def methodAsNative(m, declType="NS_IMETHOD"):
return "%s %s(%s)" % (
methodReturnType(m, declType),
methodNativeName(m),
paramlistAsNative(m),
)
def paramlistAsNative(m, empty="void", return_param=True):
l = [paramAsNative(p) for p in m.params]
if m.implicit_jscontext:
l.append("JSContext* cx")
if m.optional_argc:
l.append("uint8_t _argc")
if not m.notxpcom and m.realtype.name != "void" and return_param:
l.append(
paramAsNative(
xpidl.Param(
paramtype="out",
type=None,
name="_retval",
attlist=[],
location=None,
realtype=m.realtype,
)
)
)
# Set any optional out params to default to nullptr. Skip if we just added
# extra non-optional args to l.
if len(l) == len(m.params):
paramIter = len(m.params) - 1
while (
paramIter >= 0
and m.params[paramIter].optional
and "out" in m.params[paramIter].paramtype
):
t = m.params[paramIter].type
# Strings can't be optional, so this shouldn't happen, but let's make sure:
if t == "AString" or t == "ACString" or t == "AUTF8String":
break
l[paramIter] += " = nullptr"
paramIter -= 1
if len(l) == 0:
return empty
return ", ".join(l)
def memberCanRunScript(member):
# This can only happen if the member is scriptable and its interface is not builtinclass.
return member.isScriptable() and not member.iface.attributes.builtinclass
def runScriptAnnotation(member):
return "JS_HAZ_CAN_RUN_SCRIPT " if memberCanRunScript(member) else ""
def paramAsNative(p):
default_spec = ""
if p.default_value:
default_spec = " = " + p.default_value
return "%s%s%s" % (p.nativeType(), p.name, default_spec)
def paramlistNames(m, return_param=True):
names = [p.name for p in m.params]
if m.implicit_jscontext:
names.append("cx")
if m.optional_argc:
names.append("_argc")
if not m.notxpcom and m.realtype.name != "void" and return_param:
names.append("_retval")
if len(names) == 0:
return ""
return ", ".join(names)
header = """/*
* DO NOT EDIT. THIS FILE IS GENERATED FROM $SRCDIR/%(relpath)s
*/
#ifndef __gen_%(basename)s_h__
#define __gen_%(basename)s_h__
"""
include = """
#include "%(basename)s.h"
"""
jsvalue_include = """
#include "js/Value.h"
"""
infallible_includes = """
#include "mozilla/AlreadyAddRefed.h"
#include "mozilla/Assertions.h"
#include "mozilla/DebugOnly.h"
"""
can_run_script_includes = """
#include "js/GCAnnotations.h"
"""
header_end = """/* For IDL files that don't want to include root IDL files. */
#ifndef NS_NO_VTABLE
#define NS_NO_VTABLE
#endif
"""
footer = """
#endif /* __gen_%(basename)s_h__ */
"""
forward_decl = """class %(name)s; /* forward declaration */
"""
def idl_basename(f):
"""returns the base name of a file with the last extension stripped"""
return os.path.basename(f).rpartition(".")[0]
def print_header(idl, fd, filename, relpath):
fd.write(header % {"relpath": relpath, "basename": idl_basename(filename)})
foundinc = False
for inc in idl.includes():
if not foundinc:
foundinc = True
fd.write("\n")
fd.write(include % {"basename": idl_basename(inc.filename)})
if idl.needsJSTypes():
fd.write(jsvalue_include)
# Include some extra files if any attributes are infallible.
interfaces = [p for p in idl.productions if p.kind == "interface"]
wroteRunScriptIncludes = False
wroteInfallibleIncludes = False
for iface in interfaces:
for member in iface.members:
if not isinstance(member, xpidl.Attribute) and not isinstance(
member, xpidl.Method
):
continue
if not wroteInfallibleIncludes and member.infallible:
fd.write(infallible_includes)
wroteInfallibleIncludes = True
if not wroteRunScriptIncludes and memberCanRunScript(member):
fd.write(can_run_script_includes)
wroteRunScriptIncludes = True
if wroteRunScriptIncludes and wroteInfallibleIncludes:
break
fd.write("\n")
fd.write(header_end)
for p in idl.productions:
if p.kind == "include":
continue
if p.kind == "cdata":
fd.write(p.data)
continue
if p.kind == "webidl":
write_webidl(p, fd)
continue
if p.kind == "forward":
fd.write(forward_decl % {"name": p.name})
continue
if p.kind == "interface":
write_interface(p, fd)
continue
if p.kind == "typedef":
printComments(fd, p.doccomments, "")
fd.write("typedef %s %s;\n\n" % (p.realtype.nativeType("in"), p.name))
fd.write(footer % {"basename": idl_basename(filename)})
def write_webidl(p, fd):
path = p.native.split("::")
for seg in path[:-1]:
fd.write("namespace %s {\n" % seg)
fd.write("class %s; /* webidl %s */\n" % (path[-1], p.name))
for seg in reversed(path[:-1]):
fd.write("} // namespace %s\n" % seg)
fd.write("\n")
iface_header = r"""
/* starting interface: %(name)s */
#define %(defname)s_IID_STR "%(iid)s"
#define %(defname)s_IID \
{0x%(m0)s, 0x%(m1)s, 0x%(m2)s, \
{ %(m3joined)s }}
"""
uuid_decoder = re.compile(
r"""(?P<m0>[a-f0-9]{8})-
(?P<m1>[a-f0-9]{4})-
(?P<m2>[a-f0-9]{4})-
(?P<m3>[a-f0-9]{4})-
(?P<m4>[a-f0-9]{12})$""",
re.X,
)
iface_prolog = """ {
public:
NS_DECLARE_STATIC_IID_ACCESSOR(%(defname)s_IID)
"""
iface_scriptable = """\
/* Used by ToJSValue to check which scriptable interface is implemented. */
using ScriptableInterfaceType = %(name)s;
"""
iface_epilog = """};
NS_DEFINE_STATIC_IID_ACCESSOR(%(name)s, %(defname)s_IID)"""
iface_decl = """
/* Use this macro when declaring classes that implement this interface. */
#define NS_DECL_%(macroname)s """
iface_nonvirtual = """
/* Use this macro when declaring the members of this interface when the
class doesn't implement the interface. This is useful for forwarding. */
#define NS_DECL_NON_VIRTUAL_%(macroname)s """
iface_forward = """
/* Use this macro to declare functions that forward the behavior of this interface to another object. */
#define NS_FORWARD_%(macroname)s(_to) """ # NOQA: E501
iface_forward_safe = """
/* Use this macro to declare functions that forward the behavior of this interface to another object in a safe way. */
#define NS_FORWARD_SAFE_%(macroname)s(_to) """ # NOQA: E501
builtin_infallible_tmpl = """\
%(attributes)sinline %(realtype)s %(nativename)s(%(args)s)
{
%(realtype)sresult;
mozilla::DebugOnly<nsresult> rv = %(nativename)s(%(argnames)s&result);
MOZ_ASSERT(NS_SUCCEEDED(rv));
return result;
}
"""
# NOTE: We don't use RefPtr::forget here because we don't want to need the
# definition of %(realtype)s in scope, which we would need for the
# AddRef/Release calls.
refcnt_infallible_tmpl = """\
%(attributes)s inline already_AddRefed<%(realtype)s> %(nativename)s(%(args)s)
{
%(realtype)s* result = nullptr;
mozilla::DebugOnly<nsresult> rv = %(nativename)s(%(argnames)s&result);
MOZ_ASSERT(NS_SUCCEEDED(rv));
return already_AddRefed<%(realtype)s>(result);
}
"""
iface_threadsafe_tmpl = """\
namespace mozilla::detail {
template <>
class InterfaceNeedsThreadSafeRefCnt<%(name)s> : public std::true_type {};
}
"""
def infallibleDecl(member):
isattr = isinstance(member, xpidl.Attribute)
ismethod = isinstance(member, xpidl.Method)
assert isattr or ismethod
realtype = member.realtype.nativeType("in")
tmpl = builtin_infallible_tmpl
if member.realtype.kind != "builtin" and member.realtype.kind != "cenum":
assert realtype.endswith(" *"), "bad infallible type"
tmpl = refcnt_infallible_tmpl
realtype = realtype[:-2] # strip trailing pointer
if isattr:
nativename = attributeNativeName(member, getter=True)
args = attributeParamlist(member, getter=True, return_param=False)
argnames = attributeParamNames(member, getter=True, return_param=False)
attributes = attributeAttributes(member, getter=True)
else:
nativename = methodNativeName(member)
args = paramlistAsNative(member, return_param=False)
argnames = paramlistNames(member, return_param=False)
attributes = methodAttributes(member)
return tmpl % {
"attributes": attributes,
"realtype": realtype,
"nativename": nativename,
"args": args,
"argnames": argnames + ", " if argnames else "",
}
def write_interface(iface, fd):
if iface.namemap is None:
raise Exception("Interface was not resolved.")
# Confirm that no names of methods will overload in this interface
names = set()
def record_name(name):
if name in names:
raise Exception(
"Unexpected overloaded virtual method %s in interface %s"
% (name, iface.name)
)
names.add(name)
for m in iface.members:
if type(m) == xpidl.Attribute:
record_name(attributeNativeName(m, getter=True))
if not m.readonly:
record_name(attributeNativeName(m, getter=False))
elif type(m) == xpidl.Method:
record_name(methodNativeName(m))
def write_const_decls(g):
fd.write(" enum {\n")
enums = []
for c in g:
printComments(fd, c.doccomments, " ")
basetype = c.basetype
value = c.getValue()
enums.append(
" %(name)s = %(value)s%(signed)s"
% {
"name": c.name,
"value": value,
"signed": (not basetype.signed) and "U" or "",
}
)
fd.write(",\n".join(enums))
fd.write("\n };\n\n")
def write_cenum_decl(b):
fd.write(" enum %s : uint%d_t {\n" % (b.basename, b.width))
for var in b.variants:
fd.write(" %s = %s,\n" % (var.name, var.value))
fd.write(" };\n\n")
def write_method_decl(m):
printComments(fd, m.doccomments, " ")
fd.write(" /* %s */\n" % m.toIDL())
fd.write(" %s%s = 0;\n\n" % (runScriptAnnotation(m), methodAsNative(m)))
if m.infallible:
fd.write(infallibleDecl(m))
def write_attr_decl(a):
printComments(fd, a.doccomments, " ")
fd.write(" /* %s */\n" % a.toIDL())
fd.write(" %s%s = 0;\n" % (runScriptAnnotation(a), attributeAsNative(a, True)))
if a.infallible:
fd.write(infallibleDecl(a))
if not a.readonly:
fd.write(
" %s%s = 0;\n" % (runScriptAnnotation(a), attributeAsNative(a, False))
)
fd.write("\n")
defname = iface.name.upper()
if iface.name[0:2] == "ns":
defname = "NS_" + defname[2:]
names = uuid_decoder.match(iface.attributes.uuid).groupdict()
m3str = names["m3"] + names["m4"]
names["m3joined"] = ", ".join(["0x%s" % m3str[i : i + 2] for i in range(0, 16, 2)])
if iface.name[2] == "I":
implclass = iface.name[:2] + iface.name[3:]
else:
implclass = "_MYCLASS_"
names.update(
{
"defname": defname,
"macroname": iface.name.upper(),
"name": iface.name,
"iid": iface.attributes.uuid,
"implclass": implclass,
}
)
fd.write(iface_header % names)
printComments(fd, iface.doccomments, "")
fd.write("class ")
foundcdata = False
for m in iface.members:
if isinstance(m, xpidl.CDATA):
foundcdata = True
if not foundcdata:
fd.write("NS_NO_VTABLE ")
fd.write(iface.name)
if iface.base:
fd.write(" : public %s" % iface.base)
fd.write(iface_prolog % names)
if iface.attributes.scriptable:
fd.write(iface_scriptable % names)
for key, group in itertools.groupby(iface.members, key=type):
if key == xpidl.ConstMember:
write_const_decls(group) # iterator of all the consts
else:
for member in group:
if key == xpidl.Attribute:
write_attr_decl(member)
elif key == xpidl.Method:
write_method_decl(member)
elif key == xpidl.CDATA:
fd.write(" %s" % member.data)
elif key == xpidl.CEnum:
write_cenum_decl(member)
else:
raise Exception("Unexpected interface member: %s" % member)
fd.write(iface_epilog % names)
if iface.attributes.rust_sync:
fd.write(iface_threadsafe_tmpl % names)
fd.write(iface_decl % names)
def writeDeclaration(fd, iface, virtual):
declType = "NS_IMETHOD" if virtual else "nsresult"
suffix = " override" if virtual else ""
for member in iface.members:
if isinstance(member, xpidl.Attribute):
if member.infallible:
fd.write(
"\\\n using %s::%s; "
% (iface.name, attributeNativeName(member, True))
)
fd.write(
"\\\n %s%s; " % (attributeAsNative(member, True, declType), suffix)
)
if not member.readonly:
fd.write(
"\\\n %s%s; "
% (attributeAsNative(member, False, declType), suffix)
)
elif isinstance(member, xpidl.Method):
fd.write("\\\n %s%s; " % (methodAsNative(member, declType), suffix))
if len(iface.members) == 0:
fd.write("\\\n /* no methods! */")
elif member.kind not in ("attribute", "method"):
fd.write("\\")
writeDeclaration(fd, iface, True)
fd.write(iface_nonvirtual % names)
writeDeclaration(fd, iface, False)
fd.write(iface_forward % names)
def emitTemplate(forward_infallible, tmpl, tmpl_notxpcom=None):
if tmpl_notxpcom is None:
tmpl_notxpcom = tmpl
for member in iface.members:
if isinstance(member, xpidl.Attribute):
if forward_infallible and member.infallible:
fd.write(
"\\\n using %s::%s; "
% (iface.name, attributeNativeName(member, True))
)
attr_tmpl = tmpl_notxpcom if member.notxpcom else tmpl
fd.write(
attr_tmpl
% {
"asNative": attributeAsNative(member, True),
"nativeName": attributeNativeName(member, True),
"paramList": attributeParamNames(member, True),
}
)
if not member.readonly:
fd.write(
attr_tmpl
% {
"asNative": attributeAsNative(member, False),
"nativeName": attributeNativeName(member, False),
"paramList": attributeParamNames(member, False),
}
)
elif isinstance(member, xpidl.Method):
if member.notxpcom:
fd.write(
tmpl_notxpcom
% {
"asNative": methodAsNative(member),
"nativeName": methodNativeName(member),
"paramList": paramlistNames(member),
}
)
else:
fd.write(
tmpl
% {
"asNative": methodAsNative(member),
"nativeName": methodNativeName(member),
"paramList": paramlistNames(member),
}
)
if len(iface.members) == 0:
fd.write("\\\n /* no methods! */")
elif member.kind not in ("attribute", "method"):
fd.write("\\")
emitTemplate(
True,
"\\\n %(asNative)s override { return _to %(nativeName)s(%(paramList)s); } ",
)
fd.write(iface_forward_safe % names)
# Don't try to safely forward notxpcom functions, because we have no
# sensible default error return. Instead, the caller will have to
# implement them.
emitTemplate(
False,
"\\\n %(asNative)s override { return !_to ? NS_ERROR_NULL_POINTER : _to->%(nativeName)s(%(paramList)s); } ", # NOQA: E501
"\\\n %(asNative)s override; ",
)
fd.write("\n\n")
def main(outputfile):
xpidl.IDLParser()
if __name__ == "__main__":
main(None)