Bug Summary

File:var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/ProfilerLabels.h
Warning:line 259, column 9
Branch condition evaluates to a garbage value

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name nsJSInspector.cpp -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -ffp-contract=off -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/devtools/platform -fcoverage-compilation-dir=/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/devtools/platform -resource-dir /usr/lib/llvm-18/lib/clang/18 -include /var/lib/jenkins/workspace/firefox-scan-build/config/gcc_hidden.h -include /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/mozilla-config.h -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/stl_wrappers -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/system_wrappers -U _FORTIFY_SOURCE -D _FORTIFY_SOURCE=2 -D DEBUG=1 -D MOZ_HAS_MOZGLUE -D MOZILLA_INTERNAL_API -D IMPL_LIBXUL -D STATIC_EXPORTABLE_JS_API -I /var/lib/jenkins/workspace/firefox-scan-build/devtools/platform -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/devtools/platform -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/nspr -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/nss -D MOZILLA_CLIENT -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13 -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/x86_64-linux-gnu/c++/13 -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/backward -internal-isystem /usr/lib/llvm-18/lib/clang/18/include -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/13/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-error=tautological-type-limit-compare -Wno-invalid-offsetof -Wno-range-loop-analysis -Wno-deprecated-anon-enum-enum-conversion -Wno-deprecated-enum-enum-conversion -Wno-deprecated-this-capture -Wno-inline-new-delete -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=free-nonheap-object -Wno-error=atomic-alignment -Wno-error=deprecated-builtins -Wno-psabi -Wno-error=builtin-macro-redefined -Wno-vla-cxx-extension -Wno-unknown-warning-option -fdeprecated-macro -ferror-limit 19 -stack-protector 2 -fstack-clash-protection -ftrivial-auto-var-init=pattern -fno-rtti -fgnuc-version=4.2.1 -fno-aligned-allocation -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2024-05-16-034744-15991-1 -x c++ /var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp

/var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp

1/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
2/* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6#include "nsJSInspector.h"
7#include "mozilla/HoldDropJSObjects.h"
8#include "mozilla/SpinEventLoopUntil.h"
9#include "mozilla/dom/ScriptSettings.h"
10#include "nsTArray.h"
11
12#define JSINSPECTOR_CONTRACTID"@mozilla.org/jsinspector;1" "@mozilla.org/jsinspector;1"
13
14#define JSINSPECTOR_CID{ 0xec5aa99c, 0x7abb, 0x4142, { 0xac, 0x5f, 0xaa, 0xb2, 0x41,
0x9e, 0x38, 0xe2 } }
\
15 { \
16 0xec5aa99c, 0x7abb, 0x4142, { \
17 0xac, 0x5f, 0xaa, 0xb2, 0x41, 0x9e, 0x38, 0xe2 \
18 } \
19 }
20
21namespace mozilla {
22namespace jsinspector {
23
24NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsJSInspector)nsresult nsJSInspector::QueryInterface(const nsIID& aIID,
void** aInstancePtr) { do { if (!(aInstancePtr)) { NS_DebugBreak
(NS_DEBUG_ASSERTION, "QueryInterface requires a non-NULL destination!"
, "aInstancePtr", "/var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp"
, 24); MOZ_PretendNoReturn(); } } while (0); nsISupports* foundInterface
; if (TopThreeWordsEquals( aIID, (nsXPCOMCycleCollectionParticipant
::COMTypeInfo<nsXPCOMCycleCollectionParticipant, void>::
kIID), (nsCycleCollectionISupports::COMTypeInfo<nsCycleCollectionISupports
, void>::kIID)) && (LowWordEquals(aIID, (nsXPCOMCycleCollectionParticipant
::COMTypeInfo<nsXPCOMCycleCollectionParticipant, void>::
kIID)) || LowWordEquals(aIID, (nsCycleCollectionISupports::COMTypeInfo
<nsCycleCollectionISupports, void>::kIID)))) { if (LowWordEquals
(aIID, (nsXPCOMCycleCollectionParticipant::COMTypeInfo<nsXPCOMCycleCollectionParticipant
, void>::kIID))) { *aInstancePtr = nsJSInspector::cycleCollection
::GetParticipant(); return NS_OK; } if (LowWordEquals(aIID, (
nsCycleCollectionISupports::COMTypeInfo<nsCycleCollectionISupports
, void>::kIID))) { *aInstancePtr = nsJSInspector::cycleCollection
::Upcast(this); return NS_OK; } foundInterface = nullptr; } else
25 NS_INTERFACE_MAP_ENTRY(nsISupports)if (aIID.Equals(mozilla::detail::kImplementedIID<std::remove_reference_t
<decltype(*this)>, nsISupports>)) foundInterface = static_cast
<nsISupports*>(this); else
26 NS_INTERFACE_MAP_ENTRY(nsIJSInspector)if (aIID.Equals(mozilla::detail::kImplementedIID<std::remove_reference_t
<decltype(*this)>, nsIJSInspector>)) foundInterface =
static_cast<nsIJSInspector*>(this); else
27NS_INTERFACE_MAP_ENDfoundInterface = 0; nsresult status; if (!foundInterface) { do
{ static_assert( mozilla::detail::AssertionConditionType<
decltype(!aIID.Equals((nsISupports::COMTypeInfo<nsISupports
, void>::kIID)))>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(!aIID.Equals((nsISupports::COMTypeInfo
<nsISupports, void>::kIID))))), 0))) { do { } while (false
); MOZ_ReportAssertionFailure("!aIID.Equals((nsISupports::COMTypeInfo<nsISupports, void>::kIID))"
, "/var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp"
, 27); AnnotateMozCrashReason("MOZ_ASSERT" "(" "!aIID.Equals((nsISupports::COMTypeInfo<nsISupports, void>::kIID))"
")"); do { *((volatile int*)__null) = 27; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false); status = NS_NOINTERFACE
; } else { (foundInterface)->AddRef(); status = NS_OK; } *
aInstancePtr = foundInterface; return status; }
28
29NS_IMPL_CYCLE_COLLECTION_CLASS(nsJSInspector)nsJSInspector::cycleCollection nsJSInspector::_cycleCollectorGlobal
;
30
31NS_IMPL_CYCLE_COLLECTING_ADDREF(nsJSInspector)MozExternalRefCountType nsJSInspector::AddRef(void) { static_assert
(!std::is_destructible_v<nsJSInspector>, "Reference-counted class "
"nsJSInspector" " should not have a public destructor. " "Make this class's destructor non-public"
); do { static_assert( mozilla::detail::AssertionConditionType
<decltype(int32_t(mRefCnt) >= 0)>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(int32_t(mRefCnt) >= 0))),
0))) { do { } while (false); MOZ_ReportAssertionFailure("int32_t(mRefCnt) >= 0"
" (" "illegal refcnt" ")", "/var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp"
, 31); AnnotateMozCrashReason("MOZ_ASSERT" "(" "int32_t(mRefCnt) >= 0"
") (" "illegal refcnt" ")"); do { *((volatile int*)__null) =
31; __attribute__((nomerge)) ::abort(); } while (false); } }
while (false); _mOwningThread.AssertOwnership("nsJSInspector"
" not thread-safe"); nsISupports* base = nsJSInspector::cycleCollection
::Upcast(this); nsrefcnt count = mRefCnt.incr(base); NS_LogAddRef
((this), (count), ("nsJSInspector"), (uint32_t)(sizeof(*this)
)); return count; }
32NS_IMPL_CYCLE_COLLECTING_RELEASE(nsJSInspector)MozExternalRefCountType nsJSInspector::Release(void) { do { static_assert
( mozilla::detail::AssertionConditionType<decltype(int32_t
(mRefCnt) > 0)>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(int32_t(mRefCnt) > 0))), 0
))) { do { } while (false); MOZ_ReportAssertionFailure("int32_t(mRefCnt) > 0"
" (" "dup release" ")", "/var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp"
, 32); AnnotateMozCrashReason("MOZ_ASSERT" "(" "int32_t(mRefCnt) > 0"
") (" "dup release" ")"); do { *((volatile int*)__null) = 32
; __attribute__((nomerge)) ::abort(); } while (false); } } while
(false); _mOwningThread.AssertOwnership("nsJSInspector" " not thread-safe"
); nsISupports* base = nsJSInspector::cycleCollection::Upcast
(this); nsrefcnt count = mRefCnt.decr(base); NS_LogRelease((this
), (count), ("nsJSInspector")); return count; } void nsJSInspector
::DeleteCycleCollectable(void) { delete (this); }
33
34NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsJSInspector)nsresult nsJSInspector::cycleCollection::TraverseNative( void
* p, nsCycleCollectionTraversalCallback& cb) { nsJSInspector
* tmp = DowncastCCParticipant<nsJSInspector>(p); cb.DescribeRefCountedNode
(tmp->mRefCnt.get(), "nsJSInspector");
35NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END(void)tmp; return NS_OK; }
36
37NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsJSInspector)void nsJSInspector::cycleCollection::Unlink(void* p) { nsJSInspector
* tmp = DowncastCCParticipant<nsJSInspector>(p);
38 tmp->mRequestors.Clear();
39 tmp->mLastRequestor = JS::NullValue();
40NS_IMPL_CYCLE_COLLECTION_UNLINK_END(void)tmp; }
41
42NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsJSInspector)void nsJSInspector::cycleCollection::Trace( void* p, const TraceCallbacks
& aCallbacks, void* aClosure) { nsJSInspector* tmp = DowncastCCParticipant
<nsJSInspector>(p);
43 for (uint32_t i = 0; i < tmp->mRequestors.Length(); ++i) {
44 NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mRequestors[i])aCallbacks.Trace(&tmp->mRequestors[i], "mRequestors[i]"
, aClosure);
45 }
46 NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mLastRequestor)aCallbacks.Trace(&tmp->mLastRequestor, "mLastRequestor"
, aClosure);
47NS_IMPL_CYCLE_COLLECTION_TRACE_END(void)tmp; }
48
49nsJSInspector::nsJSInspector()
50 : mNestedLoopLevel(0), mRequestors(1), mLastRequestor(JS::NullValue()) {}
51
52nsJSInspector::~nsJSInspector() {
53 MOZ_ASSERT(mRequestors.Length() == 0)do { static_assert( mozilla::detail::AssertionConditionType<
decltype(mRequestors.Length() == 0)>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(mRequestors.Length() == 0)))
, 0))) { do { } while (false); MOZ_ReportAssertionFailure("mRequestors.Length() == 0"
, "/var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp"
, 53); AnnotateMozCrashReason("MOZ_ASSERT" "(" "mRequestors.Length() == 0"
")"); do { *((volatile int*)__null) = 53; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
54 MOZ_ASSERT(mLastRequestor.isNull())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(mLastRequestor.isNull())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(mLastRequestor.isNull()))), 0
))) { do { } while (false); MOZ_ReportAssertionFailure("mLastRequestor.isNull()"
, "/var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp"
, 54); AnnotateMozCrashReason("MOZ_ASSERT" "(" "mLastRequestor.isNull()"
")"); do { *((volatile int*)__null) = 54; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
55 mozilla::DropJSObjects(this);
56}
57
58NS_IMETHODIMPnsresult
59nsJSInspector::EnterNestedEventLoop(JS::Handle<JS::Value> requestor,
60 uint32_t* out) {
61 nsresult rv = NS_OK;
62
63 mLastRequestor = requestor;
64 mRequestors.AppendElement(requestor);
65 mozilla::HoldJSObjects(this);
66
67 mozilla::dom::AutoNoJSAPI nojsapi;
68
69 uint32_t nestLevel = ++mNestedLoopLevel;
70 if (!SpinEventLoopUntil("nsJSInspector::EnterNestedEventLoop"_ns,
1
Calling 'SpinEventLoopUntil<mozilla::ProcessFailureBehavior::ReportToCaller, (lambda at /var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp:71:27)>'
71 [&]() { return mNestedLoopLevel < nestLevel; })) {
72 rv = NS_ERROR_UNEXPECTED;
73 }
74
75 NS_ASSERTION(mNestedLoopLevel <= nestLevel,do { if (!(mNestedLoopLevel <= nestLevel)) { NS_DebugBreak
(NS_DEBUG_ASSERTION, "nested event didn't unwind properly", "mNestedLoopLevel <= nestLevel"
, "/var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp"
, 76); MOZ_PretendNoReturn(); } } while (0)
76 "nested event didn't unwind properly")do { if (!(mNestedLoopLevel <= nestLevel)) { NS_DebugBreak
(NS_DEBUG_ASSERTION, "nested event didn't unwind properly", "mNestedLoopLevel <= nestLevel"
, "/var/lib/jenkins/workspace/firefox-scan-build/devtools/platform/nsJSInspector.cpp"
, 76); MOZ_PretendNoReturn(); } } while (0)
;
77
78 if (mNestedLoopLevel == nestLevel) {
79 mLastRequestor = mRequestors.ElementAt(--mNestedLoopLevel);
80 }
81
82 *out = mNestedLoopLevel;
83 return rv;
84}
85
86NS_IMETHODIMPnsresult
87nsJSInspector::ExitNestedEventLoop(uint32_t* out) {
88 if (mNestedLoopLevel > 0) {
89 mRequestors.RemoveElementAt(--mNestedLoopLevel);
90 if (mNestedLoopLevel > 0)
91 mLastRequestor = mRequestors.ElementAt(mNestedLoopLevel - 1);
92 else
93 mLastRequestor = JS::NullValue();
94 } else {
95 return NS_ERROR_FAILURE;
96 }
97
98 *out = mNestedLoopLevel;
99
100 return NS_OK;
101}
102
103NS_IMETHODIMPnsresult
104nsJSInspector::GetEventLoopNestLevel(uint32_t* out) {
105 *out = mNestedLoopLevel;
106 return NS_OK;
107}
108
109NS_IMETHODIMPnsresult
110nsJSInspector::GetLastNestRequestor(JS::MutableHandle<JS::Value> out) {
111 out.set(mLastRequestor);
112 return NS_OK;
113}
114
115} // namespace jsinspector
116} // namespace mozilla

/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/SpinEventLoopUntil.h

1/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/* vim: set ts=8 sts=2 et sw=2 tw=80: */
3/* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7#ifndef xpcom_threads_SpinEventLoopUntil_h__
8#define xpcom_threads_SpinEventLoopUntil_h__
9
10#include "MainThreadUtils.h"
11#include "mozilla/Maybe.h"
12#include "mozilla/ProfilerLabels.h"
13#include "mozilla/ProfilerMarkers.h"
14#include "mozilla/StaticMutex.h"
15#include "nsString.h"
16#include "nsThreadUtils.h"
17#include "xpcpublic.h"
18
19class nsIThread;
20
21// A wrapper for nested event loops.
22//
23// This function is intended to make code more obvious (do you remember
24// what NS_ProcessNextEvent(nullptr, true) means?) and slightly more
25// efficient, as people often pass nullptr or NS_GetCurrentThread to
26// NS_ProcessNextEvent, which results in needless querying of the current
27// thread every time through the loop.
28//
29// You should use this function in preference to NS_ProcessNextEvent inside
30// a loop unless one of the following is true:
31//
32// * You need to pass `false` to NS_ProcessNextEvent; or
33// * You need to do unusual things around the call to NS_ProcessNextEvent,
34// such as unlocking mutexes that you are holding.
35//
36// If you *do* need to call NS_ProcessNextEvent manually, please do call
37// NS_GetCurrentThread() outside of your loop and pass the returned pointer
38// into NS_ProcessNextEvent for a tiny efficiency win.
39namespace mozilla {
40
41// You should normally not need to deal with this template parameter. If
42// you enjoy esoteric event loop details, read on.
43//
44// If you specify that NS_ProcessNextEvent wait for an event, it is possible
45// for NS_ProcessNextEvent to return false, i.e. to indicate that an event
46// was not processed. This can only happen when the thread has been shut
47// down by another thread, but is still attempting to process events outside
48// of a nested event loop.
49//
50// This behavior is admittedly strange. The scenario it deals with is the
51// following:
52//
53// * The current thread has been shut down by some owner thread.
54// * The current thread is spinning an event loop waiting for some condition
55// to become true.
56// * Said condition is actually being fulfilled by another thread, so there
57// are timing issues in play.
58//
59// Thus, there is a small window where the current thread's event loop
60// spinning can check the condition, find it false, and call
61// NS_ProcessNextEvent to wait for another event. But we don't actually
62// want it to wait indefinitely, because there might not be any other events
63// in the event loop, and the current thread can't accept dispatched events
64// because it's being shut down. Thus, actually blocking would hang the
65// thread, which is bad. The solution, then, is to detect such a scenario
66// and not actually block inside NS_ProcessNextEvent.
67//
68// But this is a problem, because we want to return the status of
69// NS_ProcessNextEvent to the caller of SpinEventLoopUntil if possible. In
70// the above scenario, however, we'd stop spinning prematurely and cause
71// all sorts of havoc. We therefore have this template parameter to
72// control whether errors are ignored or passed out to the caller of
73// SpinEventLoopUntil. The latter is the default; if you find yourself
74// wanting to use the former, you should think long and hard before doing
75// so, and write a comment like this defending your choice.
76
77enum class ProcessFailureBehavior {
78 IgnoreAndContinue,
79 ReportToCaller,
80};
81
82// SpinEventLoopUntil is a dangerous operation that can result in hangs.
83// In particular during shutdown we want to know if we are hanging
84// inside a nested event loop on the main thread.
85// This is a helper annotation class to keep track of this.
86struct MOZ_STACK_CLASS AutoNestedEventLoopAnnotation {
87 explicit AutoNestedEventLoopAnnotation(const nsACString& aEntry)
88 : mPrev(nullptr) {
89 if (NS_IsMainThread()) {
90 StaticMutexAutoLock lock(sStackMutex);
91 mPrev = sCurrent;
92 sCurrent = this;
93 if (mPrev) {
94 mStack = mPrev->mStack + "|"_ns + aEntry;
95 } else {
96 mStack = aEntry;
97 }
98 AnnotateXPCOMSpinEventLoopStack(mStack);
99 }
100 }
101
102 ~AutoNestedEventLoopAnnotation() {
103 if (NS_IsMainThread()) {
104 StaticMutexAutoLock lock(sStackMutex);
105 MOZ_ASSERT(sCurrent == this)do { static_assert( mozilla::detail::AssertionConditionType<
decltype(sCurrent == this)>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(sCurrent == this))), 0))) { do
{ } while (false); MOZ_ReportAssertionFailure("sCurrent == this"
, "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/SpinEventLoopUntil.h"
, 105); AnnotateMozCrashReason("MOZ_ASSERT" "(" "sCurrent == this"
")"); do { *((volatile int*)__null) = 105; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
106 sCurrent = mPrev;
107 if (mPrev) {
108 AnnotateXPCOMSpinEventLoopStack(mPrev->mStack);
109 } else {
110 AnnotateXPCOMSpinEventLoopStack(""_ns);
111 }
112 }
113 }
114
115 static void CopyCurrentStack(nsCString& aNestedSpinStack) {
116 // We need to copy this behind a mutex as the
117 // memory for our instances is stack-bound and
118 // can go away at any time.
119 StaticMutexAutoLock lock(sStackMutex);
120 if (sCurrent) {
121 aNestedSpinStack = sCurrent->mStack;
122 } else {
123 aNestedSpinStack = "(no nested event loop active)"_ns;
124 }
125 }
126
127 private:
128 AutoNestedEventLoopAnnotation(const AutoNestedEventLoopAnnotation&) = delete;
129 AutoNestedEventLoopAnnotation& operator=(
130 const AutoNestedEventLoopAnnotation&) = delete;
131
132 // The declarations of these statics live in nsThreadManager.cpp.
133 static AutoNestedEventLoopAnnotation* sCurrent MOZ_GUARDED_BY(sStackMutex)__attribute__((guarded_by(sStackMutex)));
134 static StaticMutex sStackMutex;
135
136 // We need this to avoid the inclusion of nsExceptionHandler.h here
137 // which can include windows.h which disturbs some dom/media/gtest.
138 // The implementation lives in nsThreadManager.cpp.
139 static void AnnotateXPCOMSpinEventLoopStack(const nsACString& aStack);
140
141 AutoNestedEventLoopAnnotation* mPrev MOZ_GUARDED_BY(sStackMutex)__attribute__((guarded_by(sStackMutex)));
142 nsCString mStack MOZ_GUARDED_BY(sStackMutex)__attribute__((guarded_by(sStackMutex)));
143};
144
145// Please see the above notes for the Behavior template parameter.
146//
147// aVeryGoodReasonToDoThis is usually a literal string unique to each
148// caller that can be recognized in the XPCOMSpinEventLoopStack
149// annotation.
150// aPredicate is the condition we wait for.
151// aThread can be used to specify a thread, see the above introduction.
152// It defaults to the current thread.
153template <
154 ProcessFailureBehavior Behavior = ProcessFailureBehavior::ReportToCaller,
155 typename Pred>
156bool SpinEventLoopUntil(const nsACString& aVeryGoodReasonToDoThis,
157 Pred&& aPredicate, nsIThread* aThread = nullptr) {
158 // Prepare the annotations
159 AutoNestedEventLoopAnnotation annotation(aVeryGoodReasonToDoThis);
160 AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING_NONSENSITIVE(mozilla::Maybe<nsAutoCString> autoCStr; mozilla::Maybe<
mozilla::AutoProfilerLabel> raiiObjectNsCString; if (profiler_is_active
()) { autoCStr.emplace(aVeryGoodReasonToDoThis); raiiObjectNsCString
.emplace( "SpinEventLoopUntil", autoCStr->get(), JS::ProfilingCategoryPair
::OTHER, uint32_t(js::ProfilingStackFrame::Flags::NONSENSITIVE
)); }
2
Calling defaulted default constructor for 'Maybe<mozilla::AutoProfilerLabel>'
13
Returning from default constructor for 'Maybe<mozilla::AutoProfilerLabel>'
14
Assuming the condition is false
15
Taking false branch
161 "SpinEventLoopUntil", OTHER, aVeryGoodReasonToDoThis)mozilla::Maybe<nsAutoCString> autoCStr; mozilla::Maybe<
mozilla::AutoProfilerLabel> raiiObjectNsCString; if (profiler_is_active
()) { autoCStr.emplace(aVeryGoodReasonToDoThis); raiiObjectNsCString
.emplace( "SpinEventLoopUntil", autoCStr->get(), JS::ProfilingCategoryPair
::OTHER, uint32_t(js::ProfilingStackFrame::Flags::NONSENSITIVE
)); }
;
162 AUTO_PROFILER_MARKER_TEXT("SpinEventLoop", OTHER, MarkerStack::Capture(),AutoProfilerTextMarker raiiObject163( "SpinEventLoop", ::mozilla
::baseprofiler::category::OTHER, MarkerStack::Capture(), aVeryGoodReasonToDoThis
)
163 aVeryGoodReasonToDoThis)AutoProfilerTextMarker raiiObject163( "SpinEventLoop", ::mozilla
::baseprofiler::category::OTHER, MarkerStack::Capture(), aVeryGoodReasonToDoThis
)
;
164
165 nsIThread* thread = aThread
15.1
'aThread' is null
15.1
'aThread' is null
15.1
'aThread' is null
15.1
'aThread' is null
15.1
'aThread' is null
? aThread : NS_GetCurrentThread();
16
'?' condition is false
166
167 // From a latency perspective, spinning the event loop is like leaving script
168 // and returning to the event loop. Tell the watchdog we stopped running
169 // script (until we return).
170 mozilla::Maybe<xpc::AutoScriptActivity> asa;
171 if (NS_IsMainThread()) {
17
Assuming the condition is false
18
Taking false branch
172 asa.emplace(false);
173 }
174
175 while (!aPredicate()) {
19
Loop condition is true. Entering loop body
176 bool didSomething = NS_ProcessNextEvent(thread, true);
177
178 if (Behavior
19.1
1 is not equal to IgnoreAndContinue
19.1
1 is not equal to IgnoreAndContinue
19.1
1 is not equal to IgnoreAndContinue
19.1
1 is not equal to IgnoreAndContinue
19.1
1 is not equal to IgnoreAndContinue
== ProcessFailureBehavior::IgnoreAndContinue) {
20
Taking false branch
179 // Don't care what happened, continue on.
180 continue;
181 } else if (!didSomething) {
21
Assuming 'didSomething' is false
22
Taking true branch
182 return false;
23
Calling implicit destructor for 'Maybe<mozilla::AutoProfilerLabel>'
24
Calling '~MaybeStorage'
183 }
184 }
185
186 return true;
187}
188
189} // namespace mozilla
190
191#endif // xpcom_threads_SpinEventLoopUntil_h__

/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h

1/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/* vim: set ts=8 sts=2 et sw=2 tw=80: */
3/* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7/* A class for optional values and in-place lazy construction. */
8
9#ifndef mozilla_Maybe_h
10#define mozilla_Maybe_h
11
12#include <functional>
13#include <new> // for placement new
14#include <ostream>
15#include <type_traits>
16#include <utility>
17
18#include "mozilla/Alignment.h"
19#include "mozilla/Assertions.h"
20#include "mozilla/Attributes.h"
21#include "mozilla/MaybeStorageBase.h"
22#include "mozilla/MemoryChecking.h"
23#include "mozilla/OperatorNewExtensions.h"
24#include "mozilla/Poison.h"
25#include "mozilla/ThreadSafety.h"
26
27class nsCycleCollectionTraversalCallback;
28
29template <typename T>
30inline void CycleCollectionNoteChild(
31 nsCycleCollectionTraversalCallback& aCallback, T* aChild, const char* aName,
32 uint32_t aFlags);
33
34namespace mozilla {
35
36struct Nothing {};
37
38inline constexpr bool operator==(const Nothing&, const Nothing&) {
39 return true;
40}
41
42template <class T>
43class Maybe;
44
45namespace detail {
46
47// You would think that poisoning Maybe instances could just be a call
48// to mozWritePoison. Unfortunately, using a simple call to
49// mozWritePoison generates poor code on MSVC for small structures. The
50// generated code contains (always not-taken) branches and does a bunch
51// of setup for `rep stos{l,q}`, even though we know at compile time
52// exactly how many words we're poisoning. Instead, we're going to
53// force MSVC to generate the code we want via recursive templates.
54
55// Write the given poisonValue into p at offset*sizeof(uintptr_t).
56template <size_t offset>
57inline void WritePoisonAtOffset(void* p, const uintptr_t poisonValue) {
58 memcpy(static_cast<char*>(p) + offset * sizeof(poisonValue), &poisonValue,
59 sizeof(poisonValue));
60}
61
62template <size_t Offset, size_t NOffsets>
63struct InlinePoisoner {
64 static void poison(void* p, const uintptr_t poisonValue) {
65 WritePoisonAtOffset<Offset>(p, poisonValue);
66 InlinePoisoner<Offset + 1, NOffsets>::poison(p, poisonValue);
67 }
68};
69
70template <size_t N>
71struct InlinePoisoner<N, N> {
72 static void poison(void*, const uintptr_t) {
73 // All done!
74 }
75};
76
77// We can't generate inline code for large structures, though, because we'll
78// blow out recursive template instantiation limits, and the code would be
79// bloated to boot. So provide a fallback to the out-of-line poisoner.
80template <size_t ObjectSize>
81struct OutOfLinePoisoner {
82 static MOZ_NEVER_INLINE__attribute__((noinline)) void poison(void* p, const uintptr_t) {
83 mozWritePoison(p, ObjectSize);
84 }
85};
86
87template <typename T>
88inline void PoisonObject(T* p) {
89 const uintptr_t POISON = mozPoisonValue();
90 std::conditional_t<(sizeof(T) <= 8 * sizeof(POISON)),
91 InlinePoisoner<0, sizeof(T) / sizeof(POISON)>,
92 OutOfLinePoisoner<sizeof(T)>>::poison(p, POISON);
93}
94
95template <typename T>
96struct MaybePoisoner {
97 static const size_t N = sizeof(T);
98
99 static void poison(void* aPtr) {
100#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED1
101 if (N >= sizeof(uintptr_t)) {
102 PoisonObject(static_cast<std::remove_cv_t<T>*>(aPtr));
103 }
104#endif
105 MOZ_MAKE_MEM_UNDEFINED(aPtr, N)do { } while (0);
106 }
107};
108
109template <typename T,
110 bool TriviallyDestructibleAndCopyable =
111 IsTriviallyDestructibleAndCopyable<T>,
112 bool Copyable = std::is_copy_constructible_v<T>,
113 bool Movable = std::is_move_constructible_v<T>>
114class Maybe_CopyMove_Enabler;
115
116#define MOZ_MAYBE_COPY_OPS() \
117 Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler& aOther) { \
118 if (downcast(aOther).isSome()) { \
119 downcast(*this).emplace(*downcast(aOther)); \
120 } \
121 } \
122 \
123 Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler& aOther) { \
124 return downcast(*this).template operator= <T>(downcast(aOther)); \
125 }
126
127#define MOZ_MAYBE_MOVE_OPS() \
128 constexpr Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&& aOther) { \
129 if (downcast(aOther).isSome()) { \
130 downcast(*this).emplace(std::move(*downcast(aOther))); \
131 downcast(aOther).reset(); \
132 } \
133 } \
134 \
135 constexpr Maybe_CopyMove_Enabler& operator=( \
136 Maybe_CopyMove_Enabler&& aOther) { \
137 downcast(*this).template operator= <T>(std::move(downcast(aOther))); \
138 \
139 return *this; \
140 }
141
142#define MOZ_MAYBE_DOWNCAST() \
143 static constexpr Maybe<T>& downcast(Maybe_CopyMove_Enabler& aObj) { \
144 return static_cast<Maybe<T>&>(aObj); \
145 } \
146 static constexpr const Maybe<T>& downcast( \
147 const Maybe_CopyMove_Enabler& aObj) { \
148 return static_cast<const Maybe<T>&>(aObj); \
149 }
150
151template <typename T>
152class Maybe_CopyMove_Enabler<T, true, true, true> {
153 public:
154 Maybe_CopyMove_Enabler() = default;
155
156 Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler&) = default;
157 Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler&) = default;
158 constexpr Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&& aOther) {
159 downcast(aOther).reset();
160 }
161 constexpr Maybe_CopyMove_Enabler& operator=(Maybe_CopyMove_Enabler&& aOther) {
162 downcast(aOther).reset();
163 return *this;
164 }
165
166 private:
167 MOZ_MAYBE_DOWNCAST()
168};
169
170template <typename T>
171class Maybe_CopyMove_Enabler<T, true, false, true> {
172 public:
173 Maybe_CopyMove_Enabler() = default;
174
175 Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler&) = delete;
176 Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler&) = delete;
177 constexpr Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&& aOther) {
178 downcast(aOther).reset();
179 }
180 constexpr Maybe_CopyMove_Enabler& operator=(Maybe_CopyMove_Enabler&& aOther) {
181 downcast(aOther).reset();
182 return *this;
183 }
184
185 private:
186 MOZ_MAYBE_DOWNCAST()
187};
188
189template <typename T>
190class Maybe_CopyMove_Enabler<T, false, true, true> {
191 public:
192 Maybe_CopyMove_Enabler() = default;
193
194 MOZ_MAYBE_COPY_OPS()
195 MOZ_MAYBE_MOVE_OPS()
196
197 private:
198 MOZ_MAYBE_DOWNCAST()
199};
200
201template <typename T>
202class Maybe_CopyMove_Enabler<T, false, false, true> {
203 public:
204 Maybe_CopyMove_Enabler() = default;
205
206 Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler&) = delete;
207 Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler&) = delete;
208 MOZ_MAYBE_MOVE_OPS()
209
210 private:
211 MOZ_MAYBE_DOWNCAST()
212};
213
214template <typename T>
215class Maybe_CopyMove_Enabler<T, false, true, false> {
216 public:
217 Maybe_CopyMove_Enabler() = default;
218
219 MOZ_MAYBE_COPY_OPS()
220 Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&&) = delete;
221 Maybe_CopyMove_Enabler& operator=(Maybe_CopyMove_Enabler&&) = delete;
222
223 private:
224 MOZ_MAYBE_DOWNCAST()
225};
226
227template <typename T, bool TriviallyDestructibleAndCopyable>
228class Maybe_CopyMove_Enabler<T, TriviallyDestructibleAndCopyable, false,
229 false> {
230 public:
231 Maybe_CopyMove_Enabler() = default;
232
233 Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler&) = delete;
234 Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler&) = delete;
235 Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&&) = delete;
236 Maybe_CopyMove_Enabler& operator=(Maybe_CopyMove_Enabler&&) = delete;
237};
238
239#undef MOZ_MAYBE_COPY_OPS
240#undef MOZ_MAYBE_MOVE_OPS
241#undef MOZ_MAYBE_DOWNCAST
242
243template <typename T, bool TriviallyDestructibleAndCopyable =
244 IsTriviallyDestructibleAndCopyable<T>>
245struct MaybeStorage;
246
247template <typename T>
248struct MaybeStorage<T, false> : MaybeStorageBase<T> {
249 protected:
250 char mIsSome = false; // not bool -- guarantees minimal space consumption
251
252 MaybeStorage() = default;
4
Calling defaulted default constructor for 'MaybeStorageBase<mozilla::AutoProfilerLabel, false>'
9
Returning from default constructor for 'MaybeStorageBase<mozilla::AutoProfilerLabel, false>'
10
Returning without writing to 'this->mStorage.val.mProfilingStack'
253 explicit MaybeStorage(const T& aVal)
254 : MaybeStorageBase<T>{aVal}, mIsSome{true} {}
255 explicit MaybeStorage(T&& aVal)
256 : MaybeStorageBase<T>{std::move(aVal)}, mIsSome{true} {}
257
258 template <typename... Args>
259 explicit MaybeStorage(std::in_place_t, Args&&... aArgs)
260 : MaybeStorageBase<T>{std::in_place, std::forward<Args>(aArgs)...},
261 mIsSome{true} {}
262
263 public:
264 // Copy and move operations are no-ops, since copying is moving is implemented
265 // by Maybe_CopyMove_Enabler.
266
267 MaybeStorage(const MaybeStorage&) : MaybeStorageBase<T>{} {}
268 MaybeStorage& operator=(const MaybeStorage&) { return *this; }
269 MaybeStorage(MaybeStorage&&) : MaybeStorageBase<T>{} {}
270 MaybeStorage& operator=(MaybeStorage&&) { return *this; }
271
272 ~MaybeStorage() {
273 if (mIsSome
24.1
Field 'mIsSome' is 0
24.1
Field 'mIsSome' is 0
24.1
Field 'mIsSome' is 0
24.1
Field 'mIsSome' is 0
24.1
Field 'mIsSome' is 0
) {
25
Taking false branch
274 this->addr()->T::~T();
275 }
276 }
26
Calling implicit destructor for 'MaybeStorageBase<mozilla::AutoProfilerLabel, false>'
27
Calling '~Union'
277};
278
279template <typename T>
280struct MaybeStorage<T, true> : MaybeStorageBase<T> {
281 protected:
282 char mIsSome = false; // not bool -- guarantees minimal space consumption
283
284 constexpr MaybeStorage() = default;
285 constexpr explicit MaybeStorage(const T& aVal)
286 : MaybeStorageBase<T>{aVal}, mIsSome{true} {}
287 constexpr explicit MaybeStorage(T&& aVal)
288 : MaybeStorageBase<T>{std::move(aVal)}, mIsSome{true} {}
289
290 template <typename... Args>
291 constexpr explicit MaybeStorage(std::in_place_t, Args&&... aArgs)
292 : MaybeStorageBase<T>{std::in_place, std::forward<Args>(aArgs)...},
293 mIsSome{true} {}
294};
295
296template <typename T>
297struct IsMaybeImpl : std::false_type {};
298
299template <typename T>
300struct IsMaybeImpl<Maybe<T>> : std::true_type {};
301
302template <typename T>
303using IsMaybe = IsMaybeImpl<std::decay_t<T>>;
304
305} // namespace detail
306
307template <typename T, typename U = typename std::remove_cv<
308 typename std::remove_reference<T>::type>::type>
309constexpr Maybe<U> Some(T&& aValue);
310
311/*
312 * Maybe is a container class which contains either zero or one elements. It
313 * serves two roles. It can represent values which are *semantically* optional,
314 * augmenting a type with an explicit 'Nothing' value. In this role, it provides
315 * methods that make it easy to work with values that may be missing, along with
316 * equality and comparison operators so that Maybe values can be stored in
317 * containers. Maybe values can be constructed conveniently in expressions using
318 * type inference, as follows:
319 *
320 * void doSomething(Maybe<Foo> aFoo) {
321 * if (aFoo) // Make sure that aFoo contains a value...
322 * aFoo->takeAction(); // and then use |aFoo->| to access it.
323 * } // |*aFoo| also works!
324 *
325 * doSomething(Nothing()); // Passes a Maybe<Foo> containing no value.
326 * doSomething(Some(Foo(100))); // Passes a Maybe<Foo> containing |Foo(100)|.
327 *
328 * You'll note that it's important to check whether a Maybe contains a value
329 * before using it, using conversion to bool, |isSome()|, or |isNothing()|. You
330 * can avoid these checks, and sometimes write more readable code, using
331 * |valueOr()|, |ptrOr()|, and |refOr()|, which allow you to retrieve the value
332 * in the Maybe and provide a default for the 'Nothing' case. You can also use
333 * |apply()| to call a function only if the Maybe holds a value, and |map()| to
334 * transform the value in the Maybe, returning another Maybe with a possibly
335 * different type.
336 *
337 * Maybe's other role is to support lazily constructing objects without using
338 * dynamic storage. A Maybe directly contains storage for a value, but it's
339 * empty by default. |emplace()|, as mentioned above, can be used to construct a
340 * value in Maybe's storage. The value a Maybe contains can be destroyed by
341 * calling |reset()|; this will happen automatically if a Maybe is destroyed
342 * while holding a value.
343 *
344 * It's a common idiom in C++ to use a pointer as a 'Maybe' type, with a null
345 * value meaning 'Nothing' and any other value meaning 'Some'. You can convert
346 * from such a pointer to a Maybe value using 'ToMaybe()'.
347 *
348 * Maybe is inspired by similar types in the standard library of many other
349 * languages (e.g. Haskell's Maybe and Rust's Option). In the C++ world it's
350 * very similar to std::optional, which was proposed for C++14 and originated in
351 * Boost. The most important differences between Maybe and std::optional are:
352 *
353 * - std::optional<T> may be compared with T. We deliberately forbid that.
354 * - std::optional has |valueOr()|, equivalent to Maybe's |valueOr()|, but
355 * lacks corresponding methods for |refOr()| and |ptrOr()|.
356 * - std::optional lacks |map()| and |apply()|, making it less suitable for
357 * functional-style code.
358 * - std::optional lacks many convenience functions that Maybe has. Most
359 * unfortunately, it lacks equivalents of the type-inferred constructor
360 * functions |Some()| and |Nothing()|.
361 */
362template <class T>
363class MOZ_INHERIT_TYPE_ANNOTATIONS_FROM_TEMPLATE_ARGS Maybe
364 : private detail::MaybeStorage<T>,
365 public detail::Maybe_CopyMove_Enabler<T> {
366 template <typename, bool, bool, bool>
367 friend class detail::Maybe_CopyMove_Enabler;
368
369 template <typename U, typename V>
370 friend constexpr Maybe<V> Some(U&& aValue);
371
372 struct SomeGuard {};
373
374 template <typename U>
375 constexpr Maybe(U&& aValue, SomeGuard)
376 : detail::MaybeStorage<T>{std::forward<U>(aValue)} {}
377
378 using detail::MaybeStorage<T>::mIsSome;
379 using detail::MaybeStorage<T>::mStorage;
380
381 void poisonData() { detail::MaybePoisoner<T>::poison(&mStorage.val); }
382
383 public:
384 using ValueType = T;
385
386 MOZ_ALLOW_TEMPORARY constexpr Maybe() = default;
3
Calling defaulted default constructor for 'MaybeStorage<mozilla::AutoProfilerLabel, false>'
11
Returning from default constructor for 'MaybeStorage<mozilla::AutoProfilerLabel, false>'
12
Returning without writing to 'this->mStorage.val.mProfilingStack'
387
388 MOZ_ALLOW_TEMPORARY MOZ_IMPLICIT constexpr Maybe(Nothing) : Maybe{} {}
389
390 template <typename... Args>
391 constexpr explicit Maybe(std::in_place_t, Args&&... aArgs)
392 : detail::MaybeStorage<T>{std::in_place, std::forward<Args>(aArgs)...} {}
393
394 /**
395 * Maybe<T> can be copy-constructed from a Maybe<U> if T is constructible from
396 * a const U&.
397 */
398 template <typename U,
399 std::enable_if_t<std::is_constructible_v<T, const U&>, bool> = true>
400 MOZ_IMPLICIT Maybe(const Maybe<U>& aOther) {
401 if (aOther.isSome()) {
402 emplace(*aOther);
403 }
404 }
405
406 template <typename U, std::enable_if_t<!std::is_constructible_v<T, const U&>,
407 bool> = true>
408 explicit Maybe(const Maybe<U>& aOther) = delete;
409
410 /**
411 * Maybe<T> can be move-constructed from a Maybe<U> if T is constructible from
412 * a U&&.
413 */
414 template <typename U,
415 std::enable_if_t<std::is_constructible_v<T, U&&>, bool> = true>
416 MOZ_IMPLICIT Maybe(Maybe<U>&& aOther) {
417 if (aOther.isSome()) {
418 emplace(std::move(*aOther));
419 aOther.reset();
420 }
421 }
422 template <typename U,
423 std::enable_if_t<!std::is_constructible_v<T, U&&>, bool> = true>
424 explicit Maybe(Maybe<U>&& aOther) = delete;
425
426 template <typename U,
427 std::enable_if_t<std::is_constructible_v<T, const U&>, bool> = true>
428 Maybe& operator=(const Maybe<U>& aOther) {
429 if (aOther.isSome()) {
430 if (mIsSome) {
431 ref() = aOther.ref();
432 } else {
433 emplace(*aOther);
434 }
435 } else {
436 reset();
437 }
438 return *this;
439 }
440
441 template <typename U, std::enable_if_t<!std::is_constructible_v<T, const U&>,
442 bool> = true>
443 Maybe& operator=(const Maybe<U>& aOther) = delete;
444
445 template <typename U,
446 std::enable_if_t<std::is_constructible_v<T, U&&>, bool> = true>
447 Maybe& operator=(Maybe<U>&& aOther) {
448 if (aOther.isSome()) {
449 if (mIsSome) {
450 ref() = std::move(aOther.ref());
451 } else {
452 emplace(std::move(*aOther));
453 }
454 aOther.reset();
455 } else {
456 reset();
457 }
458
459 return *this;
460 }
461
462 template <typename U,
463 std::enable_if_t<!std::is_constructible_v<T, U&&>, bool> = true>
464 Maybe& operator=(Maybe<U>&& aOther) = delete;
465
466 constexpr Maybe& operator=(Nothing) {
467 reset();
468 return *this;
469 }
470
471 /* Methods that check whether this Maybe contains a value */
472 constexpr explicit operator bool() const { return isSome(); }
473 constexpr bool isSome() const { return mIsSome; }
474 constexpr bool isNothing() const { return !mIsSome; }
475
476 /* Returns the contents of this Maybe<T> by value. Unsafe unless |isSome()|.
477 */
478 constexpr T value() const&;
479 constexpr T value() &&;
480 constexpr T value() const&&;
481
482 /**
483 * Move the contents of this Maybe<T> out of internal storage and return it
484 * without calling the destructor. The internal storage is also reset to
485 * avoid multiple calls. Unsafe unless |isSome()|.
486 */
487 constexpr T extract() {
488 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 488); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 488; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
489 T v = std::move(mStorage.val);
490 reset();
491 return v;
492 }
493
494 /**
495 * Returns the value (possibly |Nothing()|) by moving it out of this Maybe<T>
496 * and leaving |Nothing()| in its place.
497 */
498 Maybe<T> take() { return std::exchange(*this, Nothing()); }
499
500 /*
501 * Returns the contents of this Maybe<T> by value. If |isNothing()|, returns
502 * the default value provided.
503 *
504 * Note: If the value passed to aDefault is not the result of a trivial
505 * expression, but expensive to evaluate, e.g. |valueOr(ExpensiveFunction())|,
506 * use |valueOrFrom| instead, e.g.
507 * |valueOrFrom([arg] { return ExpensiveFunction(arg); })|. This ensures
508 * that the expensive expression is only evaluated when its result will
509 * actually be used.
510 */
511 template <typename V>
512 constexpr T valueOr(V&& aDefault) const {
513 if (isSome()) {
514 return ref();
515 }
516 return std::forward<V>(aDefault);
517 }
518
519 /*
520 * Returns the contents of this Maybe<T> by value. If |isNothing()|, returns
521 * the value returned from the function or functor provided.
522 */
523 template <typename F>
524 constexpr T valueOrFrom(F&& aFunc) const {
525 if (isSome()) {
526 return ref();
527 }
528 return aFunc();
529 }
530
531 /* Returns the contents of this Maybe<T> by pointer. Unsafe unless |isSome()|.
532 */
533 T* ptr();
534 constexpr const T* ptr() const;
535
536 /*
537 * Returns the contents of this Maybe<T> by pointer. If |isNothing()|,
538 * returns the default value provided.
539 */
540 T* ptrOr(T* aDefault) {
541 if (isSome()) {
542 return ptr();
543 }
544 return aDefault;
545 }
546
547 constexpr const T* ptrOr(const T* aDefault) const {
548 if (isSome()) {
549 return ptr();
550 }
551 return aDefault;
552 }
553
554 /*
555 * Returns the contents of this Maybe<T> by pointer. If |isNothing()|,
556 * returns the value returned from the function or functor provided.
557 */
558 template <typename F>
559 T* ptrOrFrom(F&& aFunc) {
560 if (isSome()) {
561 return ptr();
562 }
563 return aFunc();
564 }
565
566 template <typename F>
567 const T* ptrOrFrom(F&& aFunc) const {
568 if (isSome()) {
569 return ptr();
570 }
571 return aFunc();
572 }
573
574 constexpr T* operator->();
575 constexpr const T* operator->() const;
576
577 /* Returns the contents of this Maybe<T> by ref. Unsafe unless |isSome()|. */
578 constexpr T& ref() &;
579 constexpr const T& ref() const&;
580 constexpr T&& ref() &&;
581 constexpr const T&& ref() const&&;
582
583 /*
584 * Returns the contents of this Maybe<T> by ref. If |isNothing()|, returns
585 * the default value provided.
586 */
587 constexpr T& refOr(T& aDefault) {
588 if (isSome()) {
589 return ref();
590 }
591 return aDefault;
592 }
593
594 constexpr const T& refOr(const T& aDefault) const {
595 if (isSome()) {
596 return ref();
597 }
598 return aDefault;
599 }
600
601 /*
602 * Returns the contents of this Maybe<T> by ref. If |isNothing()|, returns the
603 * value returned from the function or functor provided.
604 */
605 template <typename F>
606 constexpr T& refOrFrom(F&& aFunc) {
607 if (isSome()) {
608 return ref();
609 }
610 return aFunc();
611 }
612
613 template <typename F>
614 constexpr const T& refOrFrom(F&& aFunc) const {
615 if (isSome()) {
616 return ref();
617 }
618 return aFunc();
619 }
620
621 constexpr T& operator*() &;
622 constexpr const T& operator*() const&;
623 constexpr T&& operator*() &&;
624 constexpr const T&& operator*() const&&;
625
626 /* If |isSome()|, runs the provided function or functor on the contents of
627 * this Maybe. */
628 template <typename Func>
629 constexpr Maybe& apply(Func&& aFunc) & {
630 if (isSome()) {
631 std::forward<Func>(aFunc)(ref());
632 }
633 return *this;
634 }
635
636 template <typename Func>
637 constexpr const Maybe& apply(Func&& aFunc) const& {
638 if (isSome()) {
639 std::forward<Func>(aFunc)(ref());
640 }
641 return *this;
642 }
643
644 template <typename Func>
645 constexpr Maybe& apply(Func&& aFunc) && {
646 if (isSome()) {
647 std::forward<Func>(aFunc)(extract());
648 }
649 return *this;
650 }
651
652 template <typename Func>
653 constexpr Maybe& apply(Func&& aFunc) const&& {
654 if (isSome()) {
655 std::forward<Func>(aFunc)(extract());
656 }
657 return *this;
658 }
659
660 /*
661 * If |isSome()|, runs the provided function and returns the result wrapped
662 * in a Maybe. If |isNothing()|, returns an empty Maybe value with the same
663 * value type as what the provided function would have returned.
664 */
665 template <typename Func>
666 constexpr auto map(Func&& aFunc) & {
667 if (isSome()) {
668 return Some(std::forward<Func>(aFunc)(ref()));
669 }
670 return Maybe<decltype(std::forward<Func>(aFunc)(ref()))>{};
671 }
672
673 template <typename Func>
674 constexpr auto map(Func&& aFunc) const& {
675 if (isSome()) {
676 return Some(std::forward<Func>(aFunc)(ref()));
677 }
678 return Maybe<decltype(std::forward<Func>(aFunc)(ref()))>{};
679 }
680
681 template <typename Func>
682 constexpr auto map(Func&& aFunc) && {
683 if (isSome()) {
684 return Some(std::forward<Func>(aFunc)(extract()));
685 }
686 return Maybe<decltype(std::forward<Func>(aFunc)(extract()))>{};
687 }
688
689 template <typename Func>
690 constexpr auto map(Func&& aFunc) const&& {
691 if (isSome()) {
692 return Some(std::forward<Func>(aFunc)(extract()));
693 }
694 return Maybe<decltype(std::forward<Func>(aFunc)(extract()))>{};
695 }
696
697 /*
698 * If |isSome()|, runs the provided function or functor on the contents of
699 * this Maybe and returns the result. Note that the provided function or
700 * functor must return a Maybe<U> of any type U.
701 * If |isNothing()|, returns an empty Maybe value with the same type as what
702 * the provided function would have returned.
703 */
704 template <typename Func>
705 constexpr auto andThen(Func&& aFunc) & {
706 static_assert(std::is_invocable_v<Func, T&>);
707 using U = std::invoke_result_t<Func, T&>;
708 static_assert(detail::IsMaybe<U>::value);
709 if (isSome()) {
710 return std::invoke(std::forward<Func>(aFunc), ref());
711 }
712 return std::remove_cv_t<std::remove_reference_t<U>>{};
713 }
714
715 template <typename Func>
716 constexpr auto andThen(Func&& aFunc) const& {
717 static_assert(std::is_invocable_v<Func, const T&>);
718 using U = std::invoke_result_t<Func, const T&>;
719 static_assert(detail::IsMaybe<U>::value);
720 if (isSome()) {
721 return std::invoke(std::forward<Func>(aFunc), ref());
722 }
723 return std::remove_cv_t<std::remove_reference_t<U>>{};
724 }
725
726 template <typename Func>
727 constexpr auto andThen(Func&& aFunc) && {
728 static_assert(std::is_invocable_v<Func, T&&>);
729 using U = std::invoke_result_t<Func, T&&>;
730 static_assert(detail::IsMaybe<U>::value);
731 if (isSome()) {
732 return std::invoke(std::forward<Func>(aFunc), extract());
733 }
734 return std::remove_cv_t<std::remove_reference_t<U>>{};
735 }
736
737 template <typename Func>
738 constexpr auto andThen(Func&& aFunc) const&& {
739 static_assert(std::is_invocable_v<Func, const T&&>);
740 using U = std::invoke_result_t<Func, const T&&>;
741 static_assert(detail::IsMaybe<U>::value);
742 if (isSome()) {
743 return std::invoke(std::forward<Func>(aFunc), extract());
744 }
745 return std::remove_cv_t<std::remove_reference_t<U>>{};
746 }
747
748 /*
749 * If |isNothing()|, runs the provided function or functor and returns its
750 * result. If |isSome()|, returns the contained value wrapped in a Maybe.
751 */
752 template <typename Func>
753 constexpr Maybe orElse(Func&& aFunc) & {
754 static_assert(std::is_invocable_v<Func>);
755 using U = std::invoke_result_t<Func>;
756 static_assert(
757 std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>);
758 if (isSome()) {
759 return *this;
760 }
761 return std::invoke(std::forward<Func>(aFunc));
762 }
763
764 template <typename Func>
765 constexpr Maybe orElse(Func&& aFunc) const& {
766 static_assert(std::is_invocable_v<Func>);
767 using U = std::invoke_result_t<Func>;
768 static_assert(
769 std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>);
770 if (isSome()) {
771 return *this;
772 }
773 return std::invoke(std::forward<Func>(aFunc));
774 }
775
776 template <typename Func>
777 constexpr Maybe orElse(Func&& aFunc) && {
778 static_assert(std::is_invocable_v<Func>);
779 using U = std::invoke_result_t<Func>;
780 static_assert(
781 std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>);
782 if (isSome()) {
783 return std::move(*this);
784 }
785 return std::invoke(std::forward<Func>(aFunc));
786 }
787
788 template <typename Func>
789 constexpr Maybe orElse(Func&& aFunc) const&& {
790 static_assert(std::is_invocable_v<Func>);
791 using U = std::invoke_result_t<Func>;
792 static_assert(
793 std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>);
794 if (isSome()) {
795 return std::move(*this);
796 }
797 return std::invoke(std::forward<Func>(aFunc));
798 }
799
800 /* If |isSome()|, empties this Maybe and destroys its contents. */
801 constexpr void reset() {
802 if (isSome()) {
803 if constexpr (!std::is_trivially_destructible_v<T>) {
804 /*
805 * Static analyzer gets confused if we have Maybe<MutexAutoLock>,
806 * so we suppress thread-safety warnings here
807 */
808 MOZ_PUSH_IGNORE_THREAD_SAFETYGCC diagnostic push GCC diagnostic ignored "-Wthread-safety"
809 ref().T::~T();
810 MOZ_POP_THREAD_SAFETYGCC diagnostic pop
811 poisonData();
812 }
813 mIsSome = false;
814 }
815 }
816
817 /*
818 * Constructs a T value in-place in this empty Maybe<T>'s storage. The
819 * arguments to |emplace()| are the parameters to T's constructor.
820 */
821 template <typename... Args>
822 constexpr void emplace(Args&&... aArgs);
823
824 template <typename U>
825 constexpr std::enable_if_t<std::is_same_v<T, U> &&
826 std::is_copy_constructible_v<U> &&
827 !std::is_move_constructible_v<U>>
828 emplace(U&& aArgs) {
829 emplace(aArgs);
830 }
831
832 friend std::ostream& operator<<(std::ostream& aStream,
833 const Maybe<T>& aMaybe) {
834 if (aMaybe) {
835 aStream << aMaybe.ref();
836 } else {
837 aStream << "<Nothing>";
838 }
839 return aStream;
840 }
841};
842
843template <typename T>
844class Maybe<T&> {
845 public:
846 constexpr Maybe() = default;
847 constexpr MOZ_IMPLICIT Maybe(Nothing) {}
848
849 void emplace(T& aRef) { mValue = &aRef; }
850
851 /* Methods that check whether this Maybe contains a value */
852 constexpr explicit operator bool() const { return isSome(); }
853 constexpr bool isSome() const { return mValue; }
854 constexpr bool isNothing() const { return !mValue; }
855
856 T& ref() const {
857 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 857); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 857; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
858 return *mValue;
859 }
860
861 T* operator->() const { return &ref(); }
862 T& operator*() const { return ref(); }
863
864 // Deliberately not defining value and ptr accessors, as these may be
865 // confusing on a reference-typed Maybe.
866
867 // XXX Should we define refOr?
868
869 void reset() { mValue = nullptr; }
870
871 template <typename Func>
872 const Maybe& apply(Func&& aFunc) const {
873 if (isSome()) {
874 std::forward<Func>(aFunc)(ref());
875 }
876 return *this;
877 }
878
879 template <typename Func>
880 auto map(Func&& aFunc) const {
881 Maybe<decltype(std::forward<Func>(aFunc)(ref()))> val;
882 if (isSome()) {
883 val.emplace(std::forward<Func>(aFunc)(ref()));
884 }
885 return val;
886 }
887
888 template <typename Func>
889 constexpr auto andThen(Func&& aFunc) const {
890 static_assert(std::is_invocable_v<Func, T&>);
891 using U = std::invoke_result_t<Func, T&>;
892 static_assert(detail::IsMaybe<U>::value);
893 if (isSome()) {
894 return std::invoke(std::forward<Func>(aFunc), ref());
895 }
896 return std::remove_cv_t<std::remove_reference_t<U>>{};
897 }
898
899 template <typename Func>
900 constexpr Maybe orElse(Func&& aFunc) const {
901 static_assert(std::is_invocable_v<Func>);
902 using U = std::invoke_result_t<Func>;
903 static_assert(
904 std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>);
905 if (isSome()) {
906 return *this;
907 }
908 return std::invoke(std::forward<Func>(aFunc));
909 }
910
911 bool refEquals(const Maybe<T&>& aOther) const {
912 return mValue == aOther.mValue;
913 }
914
915 bool refEquals(const T& aOther) const { return mValue == &aOther; }
916
917 private:
918 T* mValue = nullptr;
919};
920
921template <typename T>
922constexpr T Maybe<T>::value() const& {
923 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 923); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 923; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
924 return ref();
925}
926
927template <typename T>
928constexpr T Maybe<T>::value() && {
929 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 929); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 929; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
930 return std::move(ref());
931}
932
933template <typename T>
934constexpr T Maybe<T>::value() const&& {
935 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 935); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 935; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
936 return std::move(ref());
937}
938
939template <typename T>
940T* Maybe<T>::ptr() {
941 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 941); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 941; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
942 return &ref();
943}
944
945template <typename T>
946constexpr const T* Maybe<T>::ptr() const {
947 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 947); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 947; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
948 return &ref();
949}
950
951template <typename T>
952constexpr T* Maybe<T>::operator->() {
953 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 953); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 953; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
954 return ptr();
955}
956
957template <typename T>
958constexpr const T* Maybe<T>::operator->() const {
959 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 959); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 959; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
960 return ptr();
961}
962
963template <typename T>
964constexpr T& Maybe<T>::ref() & {
965 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 965); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 965; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
966 return mStorage.val;
967}
968
969template <typename T>
970constexpr const T& Maybe<T>::ref() const& {
971 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 971); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 971; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
972 return mStorage.val;
973}
974
975template <typename T>
976constexpr T&& Maybe<T>::ref() && {
977 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 977); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 977; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
978 return std::move(mStorage.val);
979}
980
981template <typename T>
982constexpr const T&& Maybe<T>::ref() const&& {
983 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 983); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 983; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
984 return std::move(mStorage.val);
985}
986
987template <typename T>
988constexpr T& Maybe<T>::operator*() & {
989 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 989); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 989; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
990 return ref();
991}
992
993template <typename T>
994constexpr const T& Maybe<T>::operator*() const& {
995 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 995); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 995; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
996 return ref();
997}
998
999template <typename T>
1000constexpr T&& Maybe<T>::operator*() && {
1001 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 1001); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 1001; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
1002 return std::move(ref());
1003}
1004
1005template <typename T>
1006constexpr const T&& Maybe<T>::operator*() const&& {
1007 MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 1007); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()"
")"); do { *((volatile int*)__null) = 1007; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
1008 return std::move(ref());
1009}
1010
1011template <typename T>
1012template <typename... Args>
1013constexpr void Maybe<T>::emplace(Args&&... aArgs) {
1014 MOZ_RELEASE_ASSERT(!isSome())do { static_assert( mozilla::detail::AssertionConditionType<
decltype(!isSome())>::isValid, "invalid assertion condition"
); if ((__builtin_expect(!!(!(!!(!isSome()))), 0))) { do { } while
(false); MOZ_ReportAssertionFailure("!isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h"
, 1014); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "!isSome()"
")"); do { *((volatile int*)__null) = 1014; __attribute__((nomerge
)) ::abort(); } while (false); } } while (false)
;
1015 ::new (KnownNotNull, &mStorage.val) T(std::forward<Args>(aArgs)...);
1016 mIsSome = true;
1017}
1018
1019/*
1020 * Some() creates a Maybe<T> value containing the provided T value. If T has a
1021 * move constructor, it's used to make this as efficient as possible.
1022 *
1023 * Some() selects the type of Maybe it returns by removing any const, volatile,
1024 * or reference qualifiers from the type of the value you pass to it. This gives
1025 * it more intuitive behavior when used in expressions, but it also means that
1026 * if you need to construct a Maybe value that holds a const, volatile, or
1027 * reference value, you need to use emplace() instead.
1028 */
1029template <typename T, typename U>
1030constexpr Maybe<U> Some(T&& aValue) {
1031 return {std::forward<T>(aValue), typename Maybe<U>::SomeGuard{}};
1032}
1033
1034template <typename T>
1035constexpr Maybe<T&> SomeRef(T& aValue) {
1036 Maybe<T&> value;
1037 value.emplace(aValue);
1038 return value;
1039}
1040
1041template <typename T>
1042constexpr Maybe<T&> ToMaybeRef(T* const aPtr) {
1043 return aPtr ? SomeRef(*aPtr) : Nothing{};
1044}
1045
1046template <typename T>
1047Maybe<std::remove_cv_t<std::remove_reference_t<T>>> ToMaybe(T* aPtr) {
1048 if (aPtr) {
1049 return Some(*aPtr);
1050 }
1051 return Nothing();
1052}
1053
1054/*
1055 * Two Maybe<T> values are equal if
1056 * - both are Nothing, or
1057 * - both are Some, and the values they contain are equal.
1058 */
1059template <typename T>
1060constexpr bool operator==(const Maybe<T>& aLHS, const Maybe<T>& aRHS) {
1061 static_assert(!std::is_reference_v<T>,
1062 "operator== is not defined for Maybe<T&>, compare values or "
1063 "addresses explicitly instead");
1064 if (aLHS.isNothing() != aRHS.isNothing()) {
1065 return false;
1066 }
1067 return aLHS.isNothing() || *aLHS == *aRHS;
1068}
1069
1070template <typename T>
1071constexpr bool operator!=(const Maybe<T>& aLHS, const Maybe<T>& aRHS) {
1072 return !(aLHS == aRHS);
1073}
1074
1075/*
1076 * We support comparison to Nothing to allow reasonable expressions like:
1077 * if (maybeValue == Nothing()) { ... }
1078 */
1079template <typename T>
1080constexpr bool operator==(const Maybe<T>& aLHS, const Nothing& aRHS) {
1081 return aLHS.isNothing();
1082}
1083
1084template <typename T>
1085constexpr bool operator!=(const Maybe<T>& aLHS, const Nothing& aRHS) {
1086 return !(aLHS == aRHS);
1087}
1088
1089template <typename T>
1090constexpr bool operator==(const Nothing& aLHS, const Maybe<T>& aRHS) {
1091 return aRHS.isNothing();
1092}
1093
1094template <typename T>
1095constexpr bool operator!=(const Nothing& aLHS, const Maybe<T>& aRHS) {
1096 return !(aLHS == aRHS);
1097}
1098
1099/*
1100 * Maybe<T> values are ordered in the same way T values are ordered, except that
1101 * Nothing comes before anything else.
1102 */
1103template <typename T>
1104constexpr bool operator<(const Maybe<T>& aLHS, const Maybe<T>& aRHS) {
1105 if (aLHS.isNothing()) {
1106 return aRHS.isSome();
1107 }
1108 if (aRHS.isNothing()) {
1109 return false;
1110 }
1111 return *aLHS < *aRHS;
1112}
1113
1114template <typename T>
1115constexpr bool operator>(const Maybe<T>& aLHS, const Maybe<T>& aRHS) {
1116 return !(aLHS < aRHS || aLHS == aRHS);
1117}
1118
1119template <typename T>
1120constexpr bool operator<=(const Maybe<T>& aLHS, const Maybe<T>& aRHS) {
1121 return aLHS < aRHS || aLHS == aRHS;
1122}
1123
1124template <typename T>
1125constexpr bool operator>=(const Maybe<T>& aLHS, const Maybe<T>& aRHS) {
1126 return !(aLHS < aRHS);
1127}
1128
1129template <typename T>
1130inline void ImplCycleCollectionTraverse(
1131 nsCycleCollectionTraversalCallback& aCallback, mozilla::Maybe<T>& aField,
1132 const char* aName, uint32_t aFlags = 0) {
1133 if (aField) {
1134 ImplCycleCollectionTraverse(aCallback, aField.ref(), aName, aFlags);
1135 }
1136}
1137
1138template <typename T>
1139inline void ImplCycleCollectionUnlink(mozilla::Maybe<T>& aField) {
1140 if (aField) {
1141 ImplCycleCollectionUnlink(aField.ref());
1142 }
1143}
1144
1145} // namespace mozilla
1146
1147#endif /* mozilla_Maybe_h */

/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/MaybeStorageBase.h

1/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/* vim: set ts=8 sts=2 et sw=2 tw=80: */
3/* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7/* Internal storage class used e.g. by Maybe and Result. This file doesn't
8 * contain any public declarations. */
9
10#ifndef mfbt_MaybeStorageBase_h
11#define mfbt_MaybeStorageBase_h
12
13#include <type_traits>
14#include <utility>
15
16namespace mozilla::detail {
17
18template <typename T>
19constexpr bool IsTriviallyDestructibleAndCopyable =
20 std::is_trivially_destructible_v<T> &&
21 (std::is_trivially_copy_constructible_v<T> ||
22 !std::is_copy_constructible_v<T>);
23
24template <typename T, bool TriviallyDestructibleAndCopyable =
25 IsTriviallyDestructibleAndCopyable<T>>
26struct MaybeStorageBase;
27
28template <typename T>
29struct MaybeStorageBase<T, false> {
30 protected:
31 using NonConstT = std::remove_const_t<T>;
32
33 union Union {
34 Union() {}
6
Returning without writing to 'this->val.mProfilingStack'
35 explicit Union(const T& aVal) : val{aVal} {}
36 template <typename U,
37 typename = std::enable_if_t<std::is_move_constructible_v<U>>>
38 explicit Union(U&& aVal) : val{std::forward<U>(aVal)} {}
39 template <typename... Args>
40 explicit Union(std::in_place_t, Args&&... aArgs)
41 : val{std::forward<Args>(aArgs)...} {}
42
43 ~Union() {}
28
Calling '~AutoProfilerLabel'
44
45 NonConstT val;
46 } mStorage;
47
48 public:
49 MaybeStorageBase() = default;
5
Calling default constructor for 'Union'
7
Returning from default constructor for 'Union'
8
Returning without writing to 'this->mStorage.val.mProfilingStack'
50 explicit MaybeStorageBase(const T& aVal) : mStorage{aVal} {}
51 explicit MaybeStorageBase(T&& aVal) : mStorage{std::move(aVal)} {}
52 template <typename... Args>
53 explicit MaybeStorageBase(std::in_place_t, Args&&... aArgs)
54 : mStorage{std::in_place, std::forward<Args>(aArgs)...} {}
55
56 const T* addr() const { return &mStorage.val; }
57 T* addr() { return &mStorage.val; }
58};
59
60template <typename T>
61struct MaybeStorageBase<T, true> {
62 protected:
63 using NonConstT = std::remove_const_t<T>;
64
65 union Union {
66 constexpr Union() : dummy() {}
67 constexpr explicit Union(const T& aVal) : val{aVal} {}
68 constexpr explicit Union(T&& aVal) : val{std::move(aVal)} {}
69 template <typename... Args>
70 constexpr explicit Union(std::in_place_t, Args&&... aArgs)
71 : val{std::forward<Args>(aArgs)...} {}
72
73 NonConstT val;
74 char dummy;
75 } mStorage;
76
77 public:
78 constexpr MaybeStorageBase() = default;
79 constexpr explicit MaybeStorageBase(const T& aVal) : mStorage{aVal} {}
80 constexpr explicit MaybeStorageBase(T&& aVal) : mStorage{std::move(aVal)} {}
81
82 template <typename... Args>
83 constexpr explicit MaybeStorageBase(std::in_place_t, Args&&... aArgs)
84 : mStorage{std::in_place, std::forward<Args>(aArgs)...} {}
85
86 constexpr const T* addr() const { return &mStorage.val; }
87 constexpr T* addr() { return &mStorage.val; }
88};
89
90} // namespace mozilla::detail
91
92#endif

/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/ProfilerLabels.h

1/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/* vim: set ts=8 sts=2 et sw=2 tw=80: */
3/* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7// This header contains all definitions related to profiler labels.
8// It is safe to include unconditionally, and only defines empty macros if
9// MOZ_GECKO_PROFILER is not set.
10
11#ifndef ProfilerLabels_h
12#define ProfilerLabels_h
13
14#include "mozilla/ProfilerState.h"
15#include "mozilla/ProfilerThreadState.h"
16
17#include "js/ProfilingCategory.h"
18#include "js/ProfilingStack.h"
19#include "js/RootingAPI.h"
20#include "mozilla/Assertions.h"
21#include "mozilla/Atomics.h"
22#include "mozilla/Attributes.h"
23#include "mozilla/BaseProfilerRAIIMacro.h"
24#include "mozilla/Maybe.h"
25#include "mozilla/ProfilerThreadRegistration.h"
26#include "mozilla/ThreadLocal.h"
27#include "nsString.h"
28
29#include <stdint.h>
30
31struct JSContext;
32
33// Insert an RAII object in this scope to enter a label stack frame. Any
34// samples collected in this scope will contain this label in their stack.
35// The label argument must be a static C string. It is usually of the
36// form "ClassName::FunctionName". (Ideally we'd use the compiler to provide
37// that for us, but __func__ gives us the function name without the class
38// name.) If the label applies to only part of a function, you can qualify it
39// like this: "ClassName::FunctionName:PartName".
40//
41// Use AUTO_PROFILER_LABEL_DYNAMIC_* if you want to add additional / dynamic
42// information to the label stack frame, and AUTO_PROFILER_LABEL_HOT if you're
43// instrumenting functions for which overhead on the order of nanoseconds is
44// noticeable.
45#define AUTO_PROFILER_LABEL(label, categoryPair)mozilla::AutoProfilerLabel raiiObject45( label, nullptr, JS::
ProfilingCategoryPair::categoryPair)
\
46 mozilla::AutoProfilerLabel PROFILER_RAIIraiiObject46( \
47 label, nullptr, JS::ProfilingCategoryPair::categoryPair)
48
49// Like AUTO_PROFILER_LABEL, but for super-hot code where overhead must be
50// kept to the absolute minimum. This variant doesn't push the label if the
51// profiler isn't running.
52// Don't use this for long-running functions: If the profiler is started in
53// the middle of the function, this label won't be on the stack until the
54// function is entered the next time. As a result, category information for
55// samples at the start of the profile can be misleading.
56// For short-running functions, that's often an acceptable trade-off.
57#define AUTO_PROFILER_LABEL_HOT(label, categoryPair)mozilla::AutoProfilerLabelHot raiiObject57( label, nullptr, JS
::ProfilingCategoryPair::categoryPair)
\
58 mozilla::AutoProfilerLabelHot PROFILER_RAIIraiiObject58( \
59 label, nullptr, JS::ProfilingCategoryPair::categoryPair)
60
61// Similar to AUTO_PROFILER_LABEL, but that adds the RELEVANT_FOR_JS flag.
62#define AUTO_PROFILER_LABEL_RELEVANT_FOR_JS(label, categoryPair)mozilla::AutoProfilerLabel raiiObject62( label, nullptr, JS::
ProfilingCategoryPair::categoryPair, uint32_t(js::ProfilingStackFrame
::Flags::RELEVANT_FOR_JS))
\
63 mozilla::AutoProfilerLabel PROFILER_RAIIraiiObject63( \
64 label, nullptr, JS::ProfilingCategoryPair::categoryPair, \
65 uint32_t(js::ProfilingStackFrame::Flags::RELEVANT_FOR_JS))
66
67// Similar to AUTO_PROFILER_LABEL, but with only one argument: the category
68// pair. The label string is taken from the category pair. This is convenient
69// for labels like AUTO_PROFILER_LABEL_CATEGORY_PAIR(GRAPHICS_LayerBuilding)
70// which would otherwise just repeat the string.
71#define AUTO_PROFILER_LABEL_CATEGORY_PAIR(categoryPair)mozilla::AutoProfilerLabel raiiObject71( "", nullptr, JS::ProfilingCategoryPair
::categoryPair, uint32_t( js::ProfilingStackFrame::Flags::LABEL_DETERMINED_BY_CATEGORY_PAIR
))
\
72 mozilla::AutoProfilerLabel PROFILER_RAIIraiiObject72( \
73 "", nullptr, JS::ProfilingCategoryPair::categoryPair, \
74 uint32_t( \
75 js::ProfilingStackFrame::Flags::LABEL_DETERMINED_BY_CATEGORY_PAIR))
76
77// Similar to AUTO_PROFILER_LABEL_CATEGORY_PAIR but adding the RELEVANT_FOR_JS
78// flag.
79#define AUTO_PROFILER_LABEL_CATEGORY_PAIR_RELEVANT_FOR_JS(categoryPair)mozilla::AutoProfilerLabel raiiObject79( "", nullptr, JS::ProfilingCategoryPair
::categoryPair, uint32_t( js::ProfilingStackFrame::Flags::LABEL_DETERMINED_BY_CATEGORY_PAIR
) | uint32_t(js::ProfilingStackFrame::Flags::RELEVANT_FOR_JS)
)
\
80 mozilla::AutoProfilerLabel PROFILER_RAIIraiiObject80( \
81 "", nullptr, JS::ProfilingCategoryPair::categoryPair, \
82 uint32_t( \
83 js::ProfilingStackFrame::Flags::LABEL_DETERMINED_BY_CATEGORY_PAIR) | \
84 uint32_t(js::ProfilingStackFrame::Flags::RELEVANT_FOR_JS))
85
86// Similar to AUTO_PROFILER_LABEL, but with an additional string. The inserted
87// RAII object stores the cStr pointer in a field; it does not copy the string.
88//
89// WARNING: This means that the string you pass to this macro needs to live at
90// least until the end of the current scope. Be careful using this macro with
91// ns[C]String; the other AUTO_PROFILER_LABEL_DYNAMIC_* macros below are
92// preferred because they avoid this problem.
93//
94// If the profiler samples the current thread and walks the label stack while
95// this RAII object is on the stack, it will copy the supplied string into the
96// profile buffer. So there's one string copy operation, and it happens at
97// sample time.
98//
99// Compare this to the plain AUTO_PROFILER_LABEL macro, which only accepts
100// literal strings: When the label stack frames generated by
101// AUTO_PROFILER_LABEL are sampled, no string copy needs to be made because the
102// profile buffer can just store the raw pointers to the literal strings.
103// Consequently, AUTO_PROFILER_LABEL frames take up considerably less space in
104// the profile buffer than AUTO_PROFILER_LABEL_DYNAMIC_* frames.
105#define AUTO_PROFILER_LABEL_DYNAMIC_CSTR(label, categoryPair, cStr)mozilla::AutoProfilerLabel raiiObject105( label, cStr, JS::ProfilingCategoryPair
::categoryPair)
\
106 mozilla::AutoProfilerLabel PROFILER_RAIIraiiObject106( \
107 label, cStr, JS::ProfilingCategoryPair::categoryPair)
108
109// Like AUTO_PROFILER_LABEL_DYNAMIC_CSTR, but with the NONSENSITIVE flag to
110// note that it does not contain sensitive information (so we can include it
111// in, for example, the BackgroundHangMonitor)
112#define AUTO_PROFILER_LABEL_DYNAMIC_CSTR_NONSENSITIVE(label, categoryPair, \mozilla::AutoProfilerLabel raiiObject113( label, cStr, JS::ProfilingCategoryPair
::categoryPair, uint32_t(js::ProfilingStackFrame::Flags::NONSENSITIVE
))
113 cStr)mozilla::AutoProfilerLabel raiiObject113( label, cStr, JS::ProfilingCategoryPair
::categoryPair, uint32_t(js::ProfilingStackFrame::Flags::NONSENSITIVE
))
\
114 mozilla::AutoProfilerLabel PROFILER_RAIIraiiObject114( \
115 label, cStr, JS::ProfilingCategoryPair::categoryPair, \
116 uint32_t(js::ProfilingStackFrame::Flags::NONSENSITIVE))
117
118// Similar to AUTO_PROFILER_LABEL_DYNAMIC_CSTR, but takes an nsACString.
119//
120// Note: The use of the Maybe<>s ensures the scopes for the dynamic string and
121// the AutoProfilerLabel are appropriate, while also not incurring the runtime
122// cost of the string assignment unless the profiler is active. Therefore,
123// unlike AUTO_PROFILER_LABEL and AUTO_PROFILER_LABEL_DYNAMIC_CSTR, this macro
124// doesn't push/pop a label when the profiler is inactive.
125#define AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING(label, categoryPair, nsCStr)mozilla::Maybe<nsAutoCString> autoCStr; mozilla::Maybe<
mozilla::AutoProfilerLabel> raiiObjectNsCString; if (profiler_is_active
()) { autoCStr.emplace(nsCStr); raiiObjectNsCString.emplace(label
, autoCStr->get(), JS::ProfilingCategoryPair::categoryPair
); }
\
126 mozilla::Maybe<nsAutoCString> autoCStr; \
127 mozilla::Maybe<mozilla::AutoProfilerLabel> raiiObjectNsCString; \
128 if (profiler_is_active()) { \
129 autoCStr.emplace(nsCStr); \
130 raiiObjectNsCString.emplace(label, autoCStr->get(), \
131 JS::ProfilingCategoryPair::categoryPair); \
132 }
133
134#define AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING_RELEVANT_FOR_JS( \mozilla::Maybe<nsAutoCString> autoCStr; mozilla::Maybe<
mozilla::AutoProfilerLabel> raiiObjectNsCString; if (profiler_is_active
()) { autoCStr.emplace(nsCStr); raiiObjectNsCString.emplace( label
, autoCStr->get(), JS::ProfilingCategoryPair::categoryPair
, uint32_t(js::ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
}
135 label, categoryPair, nsCStr)mozilla::Maybe<nsAutoCString> autoCStr; mozilla::Maybe<
mozilla::AutoProfilerLabel> raiiObjectNsCString; if (profiler_is_active
()) { autoCStr.emplace(nsCStr); raiiObjectNsCString.emplace( label
, autoCStr->get(), JS::ProfilingCategoryPair::categoryPair
, uint32_t(js::ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
}
\
136 mozilla::Maybe<nsAutoCString> autoCStr; \
137 mozilla::Maybe<mozilla::AutoProfilerLabel> raiiObjectNsCString; \
138 if (profiler_is_active()) { \
139 autoCStr.emplace(nsCStr); \
140 raiiObjectNsCString.emplace( \
141 label, autoCStr->get(), JS::ProfilingCategoryPair::categoryPair, \
142 uint32_t(js::ProfilingStackFrame::Flags::RELEVANT_FOR_JS)); \
143 }
144
145// Match the conditions for MOZ_ENABLE_BACKGROUND_HANG_MONITOR
146#if defined(NIGHTLY_BUILD1) && !defined(MOZ_DEBUG1) && !defined(MOZ_TSAN) && \
147 !defined(MOZ_ASAN)
148# define SHOULD_CREATE_ALL_NONSENSITIVE_LABEL_FRAMESprofiler_is_active() true
149#else
150# define SHOULD_CREATE_ALL_NONSENSITIVE_LABEL_FRAMESprofiler_is_active() profiler_is_active()
151#endif
152
153// See note above AUTO_PROFILER_LABEL_DYNAMIC_CSTR_NONSENSITIVE
154#define AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING_NONSENSITIVE( \mozilla::Maybe<nsAutoCString> autoCStr; mozilla::Maybe<
mozilla::AutoProfilerLabel> raiiObjectNsCString; if (profiler_is_active
()) { autoCStr.emplace(nsCStr); raiiObjectNsCString.emplace( label
, autoCStr->get(), JS::ProfilingCategoryPair::categoryPair
, uint32_t(js::ProfilingStackFrame::Flags::NONSENSITIVE)); }
155 label, categoryPair, nsCStr)mozilla::Maybe<nsAutoCString> autoCStr; mozilla::Maybe<
mozilla::AutoProfilerLabel> raiiObjectNsCString; if (profiler_is_active
()) { autoCStr.emplace(nsCStr); raiiObjectNsCString.emplace( label
, autoCStr->get(), JS::ProfilingCategoryPair::categoryPair
, uint32_t(js::ProfilingStackFrame::Flags::NONSENSITIVE)); }
\
156 mozilla::Maybe<nsAutoCString> autoCStr; \
157 mozilla::Maybe<mozilla::AutoProfilerLabel> raiiObjectNsCString; \
158 if (SHOULD_CREATE_ALL_NONSENSITIVE_LABEL_FRAMESprofiler_is_active()) { \
159 autoCStr.emplace(nsCStr); \
160 raiiObjectNsCString.emplace( \
161 label, autoCStr->get(), JS::ProfilingCategoryPair::categoryPair, \
162 uint32_t(js::ProfilingStackFrame::Flags::NONSENSITIVE)); \
163 }
164
165// Similar to AUTO_PROFILER_LABEL_DYNAMIC_CSTR, but takes an nsString that is
166// is lossily converted to an ASCII string.
167//
168// Note: The use of the Maybe<>s ensures the scopes for the converted dynamic
169// string and the AutoProfilerLabel are appropriate, while also not incurring
170// the runtime cost of the string conversion unless the profiler is active.
171// Therefore, unlike AUTO_PROFILER_LABEL and AUTO_PROFILER_LABEL_DYNAMIC_CSTR,
172// this macro doesn't push/pop a label when the profiler is inactive.
173#define AUTO_PROFILER_LABEL_DYNAMIC_LOSSY_NSSTRING(label, categoryPair, nsStr)mozilla::Maybe<NS_LossyConvertUTF16toASCII> asciiStr; mozilla
::Maybe<mozilla::AutoProfilerLabel> raiiObjectLossyNsString
; if (profiler_is_active()) { asciiStr.emplace(nsStr); raiiObjectLossyNsString
.emplace(label, asciiStr->get(), JS::ProfilingCategoryPair
::categoryPair); }
\
174 mozilla::Maybe<NS_LossyConvertUTF16toASCII> asciiStr; \
175 mozilla::Maybe<mozilla::AutoProfilerLabel> raiiObjectLossyNsString; \
176 if (profiler_is_active()) { \
177 asciiStr.emplace(nsStr); \
178 raiiObjectLossyNsString.emplace(label, asciiStr->get(), \
179 JS::ProfilingCategoryPair::categoryPair); \
180 }
181
182// Similar to AUTO_PROFILER_LABEL, but accepting a JSContext* parameter, and a
183// no-op if the profiler is disabled.
184// Used to annotate functions for which overhead in the range of nanoseconds is
185// noticeable. It avoids overhead from the TLS lookup because it can get the
186// ProfilingStack from the JS context, and avoids almost all overhead in the
187// case where the profiler is disabled.
188#define AUTO_PROFILER_LABEL_FAST(label, categoryPair, ctx)mozilla::AutoProfilerLabelHot raiiObject188( ctx, label, nullptr
, JS::ProfilingCategoryPair::categoryPair)
\
189 mozilla::AutoProfilerLabelHot PROFILER_RAIIraiiObject189( \
190 ctx, label, nullptr, JS::ProfilingCategoryPair::categoryPair)
191
192// Similar to AUTO_PROFILER_LABEL_FAST, but also takes an extra string and an
193// additional set of flags. The flags parameter should carry values from the
194// js::ProfilingStackFrame::Flags enum.
195#define AUTO_PROFILER_LABEL_DYNAMIC_FAST(label, dynamicString, categoryPair, \mozilla::AutoProfilerLabelHot raiiObject196( ctx, label, dynamicString
, JS::ProfilingCategoryPair::categoryPair, flags)
196 ctx, flags)mozilla::AutoProfilerLabelHot raiiObject196( ctx, label, dynamicString
, JS::ProfilingCategoryPair::categoryPair, flags)
\
197 mozilla::AutoProfilerLabelHot PROFILER_RAIIraiiObject197( \
198 ctx, label, dynamicString, JS::ProfilingCategoryPair::categoryPair, \
199 flags)
200
201namespace mozilla {
202
203#ifndef MOZ_GECKO_PROFILER1
204
205class MOZ_RAII AutoProfilerLabel {
206 public:
207 // This is the AUTO_PROFILER_LABEL and AUTO_PROFILER_LABEL_DYNAMIC variant.
208 AutoProfilerLabel(const char* aLabel, const char* aDynamicString,
209 JS::ProfilingCategoryPair aCategoryPair,
210 uint32_t aFlags = 0) {}
211
212 ~AutoProfilerLabel() {}
213};
214
215class MOZ_RAII AutoProfilerLabelHot {
216 public:
217 // This is the AUTO_PROFILER_LABEL_HOT variant.
218 AutoProfilerLabelHot(const char* aLabel, const char* aDynamicString,
219 JS::ProfilingCategoryPair aCategoryPair,
220 uint32_t aFlags = 0) {}
221
222 // This is the AUTO_PROFILER_LABEL_FAST variant.
223 AutoProfilerLabelHot(JSContext* aJSContext, const char* aLabel,
224 const char* aDynamicString,
225 JS::ProfilingCategoryPair aCategoryPair,
226 uint32_t aFlags) {}
227
228 ~AutoProfilerLabelHot() {}
229};
230
231#else // !MOZ_GECKO_PROFILER
232
233// This class creates a non-owning ProfilingStack reference. Objects of this
234// class are stack-allocated, and so exist within a thread, and are thus bounded
235// by the lifetime of the thread, which ensures that the references held can't
236// be used after the ProfilingStack is destroyed.
237class MOZ_RAII AutoProfilerLabel {
238 public:
239 // This is the AUTO_PROFILER_LABEL and AUTO_PROFILER_LABEL_DYNAMIC variant.
240 AutoProfilerLabel(const char* aLabel, const char* aDynamicString,
241 JS::ProfilingCategoryPair aCategoryPair,
242 uint32_t aFlags = 0) {
243 // Get the ProfilingStack from TLS.
244 mProfilingStack = profiler::ThreadRegistration::WithOnThreadRefOr(
245 [](profiler::ThreadRegistration::OnThreadRef aThread) {
246 return &aThread.UnlockedConstReaderAndAtomicRWRef()
247 .ProfilingStackRef();
248 },
249 nullptr);
250 if (mProfilingStack) {
251 mProfilingStack->pushLabelFrame(aLabel, aDynamicString, this,
252 aCategoryPair, aFlags);
253 }
254 }
255
256 ~AutoProfilerLabel() {
257 // This function runs both on and off the main thread.
258
259 if (mProfilingStack) {
29
Branch condition evaluates to a garbage value
260 mProfilingStack->pop();
261 }
262 }
263
264 private:
265 // We save a ProfilingStack pointer in the ctor so we don't have to redo the
266 // TLS lookup in the dtor.
267 ProfilingStack* mProfilingStack;
268};
269
270class MOZ_RAII AutoProfilerLabelHot {
271 public:
272 // This is the AUTO_PROFILER_LABEL_HOT variant. It does nothing if
273 // the profiler is inactive.
274 AutoProfilerLabelHot(const char* aLabel, const char* aDynamicString,
275 JS::ProfilingCategoryPair aCategoryPair,
276 uint32_t aFlags = 0) {
277 if (MOZ_LIKELY(!profiler_is_active())(__builtin_expect(!!(!profiler_is_active()), 1))) {
278 mProfilingStack = nullptr;
279 return;
280 }
281
282 // Get the ProfilingStack from TLS.
283 mProfilingStack = profiler::ThreadRegistration::WithOnThreadRefOr(
284 [](profiler::ThreadRegistration::OnThreadRef aThread) {
285 return &aThread.UnlockedConstReaderAndAtomicRWRef()
286 .ProfilingStackRef();
287 },
288 nullptr);
289 if (mProfilingStack) {
290 mProfilingStack->pushLabelFrame(aLabel, aDynamicString, this,
291 aCategoryPair, aFlags);
292 }
293 }
294
295 // This is the AUTO_PROFILER_LABEL_FAST variant. It retrieves the
296 // ProfilingStack from the JSContext and does nothing if the profiler is
297 // inactive.
298 AutoProfilerLabelHot(JSContext* aJSContext, const char* aLabel,
299 const char* aDynamicString,
300 JS::ProfilingCategoryPair aCategoryPair,
301 uint32_t aFlags) {
302 mProfilingStack = js::GetContextProfilingStackIfEnabled(aJSContext);
303 if (MOZ_UNLIKELY(mProfilingStack)(__builtin_expect(!!(mProfilingStack), 0))) {
304 mProfilingStack->pushLabelFrame(aLabel, aDynamicString, this,
305 aCategoryPair, aFlags);
306 }
307 }
308
309 ~AutoProfilerLabelHot() {
310 // This function runs both on and off the main thread.
311 if (MOZ_UNLIKELY(mProfilingStack)(__builtin_expect(!!(mProfilingStack), 0))) {
312 mProfilingStack->pop();
313 }
314 }
315
316 private:
317 // We save a ProfilingStack pointer in the ctor so we don't have to redo the
318 // TLS lookup in the dtor.
319 ProfilingStack* mProfilingStack;
320};
321
322#endif // !MOZ_GECKO_PROFILER
323
324} // namespace mozilla
325
326#endif // ProfilerLabels_h