gecko-dev/mfbt/MaybeOneOf.h
Emilio Cobos Álvarez 256c124f94 Bug 1609996 - Reorder some includes affected by the previous patches. r=froydnj
This was done by:

This was done by applying:

```
diff --git a/python/mozbuild/mozbuild/code-analysis/mach_commands.py b/python/mozbuild/mozbuild/code-analysis/mach_commands.py
index 789affde7bbf..fe33c4c7d4d1 100644
--- a/python/mozbuild/mozbuild/code-analysis/mach_commands.py
+++ b/python/mozbuild/mozbuild/code-analysis/mach_commands.py
@@ -2007,7 +2007,7 @@ class StaticAnalysis(MachCommandBase):
         from subprocess import Popen, PIPE, check_output, CalledProcessError

         diff_process = Popen(self._get_clang_format_diff_command(commit), stdout=PIPE)
-        args = [sys.executable, clang_format_diff, "-p1", "-binary=%s" % clang_format]
+        args = [sys.executable, clang_format_diff, "-p1", "-binary=%s" % clang_format, '-sort-includes']

         if not output_file:
             args.append("-i")
```

Then running `./mach clang-format -c <commit-hash>`

Then undoing that patch.

Then running check_spidermonkey_style.py --fixup

Then running `./mach clang-format`

I had to fix four things:

 * I needed to move <utility> back down in GuardObjects.h because I was hitting
   obscure problems with our system include wrappers like this:

0:03.94 /usr/include/stdlib.h:550:14: error: exception specification in declaration does not match previous declaration
0:03.94 extern void *realloc (void *__ptr, size_t __size)
0:03.94              ^
0:03.94 /home/emilio/src/moz/gecko-2/obj-debug/dist/include/malloc_decls.h:53:1: note: previous declaration is here
0:03.94 MALLOC_DECL(realloc, void*, void*, size_t)
0:03.94 ^
0:03.94 /home/emilio/src/moz/gecko-2/obj-debug/dist/include/mozilla/mozalloc.h:22:32: note: expanded from macro 'MALLOC_DECL'
0:03.94     MOZ_MEMORY_API return_type name##_impl(__VA_ARGS__);
0:03.94                                ^
0:03.94 <scratch space>:178:1: note: expanded from here
0:03.94 realloc_impl
0:03.94 ^
0:03.94 /home/emilio/src/moz/gecko-2/obj-debug/dist/include/mozmemory_wrap.h:142:41: note: expanded from macro 'realloc_impl'
0:03.94 #define realloc_impl mozmem_malloc_impl(realloc)

   Which I really didn't feel like digging into.

 * I had to restore the order of TrustOverrideUtils.h and related files in nss
   because the .inc files depend on TrustOverrideUtils.h being included earlier.

 * I had to add a missing include to RollingNumber.h

 * Also had to partially restore include order in JsepSessionImpl.cpp to avoid
   some -WError issues due to some static inline functions being defined in a
   header but not used in the rest of the compilation unit.

Differential Revision: https://phabricator.services.mozilla.com/D60327

--HG--
extra : moz-landing-system : lando
2020-01-20 16:19:48 +00:00

156 lines
4.3 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */
/*
* A class storing one of two optional value types that supports in-place lazy
* construction.
*/
#ifndef mozilla_MaybeOneOf_h
#define mozilla_MaybeOneOf_h
#include <stddef.h> // for size_t
#include <new> // for placement new
#include <utility>
#include "mozilla/Assertions.h"
#include "mozilla/OperatorNewExtensions.h"
#include "mozilla/TemplateLib.h"
namespace mozilla {
/*
* MaybeOneOf<T1, T2> is like Maybe, but it supports constructing either T1
* or T2. When a MaybeOneOf<T1, T2> is constructed, it is |empty()|, i.e.,
* no value has been constructed and no destructor will be called when the
* MaybeOneOf<T1, T2> is destroyed. Upon calling |construct<T1>()| or
* |construct<T2>()|, a T1 or T2 object will be constructed with the given
* arguments and that object will be destroyed when the owning MaybeOneOf is
* destroyed.
*
* Because MaybeOneOf must be aligned suitable to hold any value stored within
* it, and because |alignas| requirements don't affect platform ABI with respect
* to how parameters are laid out in memory, MaybeOneOf can't be used as the
* type of a function parameter. Pass MaybeOneOf to functions by pointer or
* reference instead.
*/
template <class T1, class T2>
class MOZ_NON_PARAM MaybeOneOf {
static constexpr size_t StorageAlignment =
tl::Max<alignof(T1), alignof(T2)>::value;
static constexpr size_t StorageSize = tl::Max<sizeof(T1), sizeof(T2)>::value;
alignas(StorageAlignment) unsigned char storage[StorageSize];
// GCC fails due to -Werror=strict-aliasing if |storage| is directly cast to
// T*. Indirecting through these functions addresses the problem.
void* data() { return storage; }
const void* data() const { return storage; }
enum State { None, SomeT1, SomeT2 } state;
template <class T, class Ignored = void>
struct Type2State {};
template <class T>
T& as() {
MOZ_ASSERT(state == Type2State<T>::result);
return *static_cast<T*>(data());
}
template <class T>
const T& as() const {
MOZ_ASSERT(state == Type2State<T>::result);
return *static_cast<const T*>(data());
}
public:
MaybeOneOf() : state(None) {}
~MaybeOneOf() { destroyIfConstructed(); }
MaybeOneOf(MaybeOneOf&& rhs) : state(None) {
if (!rhs.empty()) {
if (rhs.constructed<T1>()) {
construct<T1>(std::move(rhs.as<T1>()));
rhs.as<T1>().~T1();
} else {
construct<T2>(std::move(rhs.as<T2>()));
rhs.as<T2>().~T2();
}
rhs.state = None;
}
}
MaybeOneOf& operator=(MaybeOneOf&& rhs) {
MOZ_ASSERT(this != &rhs, "Self-move is prohibited");
this->~MaybeOneOf();
new (this) MaybeOneOf(std::move(rhs));
return *this;
}
bool empty() const { return state == None; }
template <class T>
bool constructed() const {
return state == Type2State<T>::result;
}
template <class T, class... Args>
void construct(Args&&... aArgs) {
MOZ_ASSERT(state == None);
state = Type2State<T>::result;
::new (KnownNotNull, data()) T(std::forward<Args>(aArgs)...);
}
template <class T>
T& ref() {
return as<T>();
}
template <class T>
const T& ref() const {
return as<T>();
}
void destroy() {
MOZ_ASSERT(state == SomeT1 || state == SomeT2);
if (state == SomeT1) {
as<T1>().~T1();
} else if (state == SomeT2) {
as<T2>().~T2();
}
state = None;
}
void destroyIfConstructed() {
if (!empty()) {
destroy();
}
}
private:
MaybeOneOf(const MaybeOneOf& aOther) = delete;
const MaybeOneOf& operator=(const MaybeOneOf& aOther) = delete;
};
template <class T1, class T2>
template <class Ignored>
struct MaybeOneOf<T1, T2>::Type2State<T1, Ignored> {
typedef MaybeOneOf<T1, T2> Enclosing;
static const typename Enclosing::State result = Enclosing::SomeT1;
};
template <class T1, class T2>
template <class Ignored>
struct MaybeOneOf<T1, T2>::Type2State<T2, Ignored> {
typedef MaybeOneOf<T1, T2> Enclosing;
static const typename Enclosing::State result = Enclosing::SomeT2;
};
} // namespace mozilla
#endif /* mozilla_MaybeOneOf_h */