gnu: Add mozjs-38 (Mozilla SpiderMonkey 38).

* gnu/packages/gnuzilla.scm (mozjs-38): New variable.
* gnu/packages/patches/mozjs38-pkg-config-version.patch,
gnu/packages/patches/mozjs38-shell-version.patch,
gnu/packages/patches/mozjs38-tracelogger.patch,
gnu/packages/patches/mozjs38-version-detection.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.

Co-authored-by: ng0 <ng0@no-reply.pragmatique.xyz>

1 files changed, 608 insertions, 0 deletions

diff --git a/gnu/packages/patches/mozjs38-tracelogger.patch b/gnu/packages/patches/mozjs38-tracelogger.patch
new file mode 100644
index 0000000000..0375ec36cc
--- /dev/null
+++ b/gnu/packages/patches/mozjs38-tracelogger.patch
@@ -0,0 +1,608 @@
+Squashed version of several commits to fix the tracelogger.
+
+Taken from
+https://github.com/GNOME/jhbuild/blob/master/patches/mozjs38-fix-tracelogger.patch.
+
+# === Fix the SM38 tracelogger ===
+# This patch is a squashed version of several patches that were adapted
+# to fix failing hunks.
+#
+# Applied in the following order, they are:
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1223767
+#    Assertion failure: i < size_, at js/src/vm/TraceLoggingTypes.h:210 
+#    Also fix stop-information to make reduce.py work correctly.
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1227914
+#    Limit the memory tracelogger can take.
+#    This causes tracelogger to flush data to the disk regularly and prevents out of 
+#    memory issues if a lot of data gets logged.
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1155618
+#    Fix tracelogger destructor that touches possibly uninitialised hash table.
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1223636
+#    Don't treat extraTextId as containing only extra ids.
+#    This fixes an assertion failure: id == nextTextId at js/src/vm/TraceLoggingGraph.cpp
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1227028
+#    Fix when to keep the payload of a TraceLogger event.
+#    This fixes an assertion failure: textId < uint32_t(1 << 31) at js/src/vm/TraceLoggingGraph.h
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1266649
+#    Handle failing to add to pointermap gracefully.
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1280648
+#    Don't cache based on pointers to movable GC things.
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1224123
+#    Fix the use of LastEntryId in tracelogger.h.
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1231170
+#    Use size in debugger instead of the current id to track last logged item.
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1221844
+#    Move TraceLogger_Invalidation to LOG_ITEM.
+#    Add some debug checks to logTimestamp.
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1255766
+#    Also mark resizing of memory.
+# * https://bugzilla.mozilla.org/show_bug.cgi?id=1259403
+#    Only increase capacity by multiples of 2.
+#    Always make sure there are 3 free slots for events.
+# ===
+
+diff --git a/js/src/jit-test/tests/tracelogger/bug1231170.js b/js/src/jit-test/tests/tracelogger/bug1231170.js
+new file mode 100644
+index 0000000..023e93e
+--- /dev/null
++++ b/js/src/jit-test/tests/tracelogger/bug1231170.js
+@@ -0,0 +1,3 @@
++var du = new Debugger();
++if (typeof du.drainTraceLogger === "function")
++    du.drainTraceLogger();
+diff --git a/js/src/jit-test/tests/tracelogger/bug1266649.js b/js/src/jit-test/tests/tracelogger/bug1266649.js
+new file mode 100644
+index 0000000..81ae7ad
+--- /dev/null
++++ b/js/src/jit-test/tests/tracelogger/bug1266649.js
+@@ -0,0 +1,10 @@
++
++var du = new Debugger();
++if (typeof du.setupTraceLogger === "function" &&
++    typeof oomTest === 'function')
++{
++    du.setupTraceLogger({
++        Scripts: true
++    })
++    oomTest(() => function(){});
++}
+diff --git a/js/src/jit/Ion.cpp b/js/src/jit/Ion.cpp
+index 93e2fda..09049d6 100644
+--- a/js/src/jit/Ion.cpp
++++ b/js/src/jit/Ion.cpp
+@@ -1055,6 +1055,8 @@ IonScript::Destroy(FreeOp* fop, IonScript* script)
+ 
+     script->destroyCaches();
+     script->unlinkFromRuntime(fop);
++    // Frees the potential event we have set.
++    script->traceLoggerScriptEvent_ = TraceLoggerEvent();
+     fop->free_(script);
+ }
+ 
+diff --git a/js/src/vm/Debugger.cpp b/js/src/vm/Debugger.cpp
+index 26262fd..af7f313 100644
+--- a/js/src/vm/Debugger.cpp
++++ b/js/src/vm/Debugger.cpp
+@@ -369,10 +369,10 @@ Debugger::Debugger(JSContext* cx, NativeObject* dbg)
+     objects(cx),
+     environments(cx),
+ #ifdef NIGHTLY_BUILD
+-    traceLoggerLastDrainedId(0),
++    traceLoggerLastDrainedSize(0),
+     traceLoggerLastDrainedIteration(0),
+ #endif
+-    traceLoggerScriptedCallsLastDrainedId(0),
++    traceLoggerScriptedCallsLastDrainedSize(0),
+     traceLoggerScriptedCallsLastDrainedIteration(0)
+ {
+     assertSameCompartment(cx, dbg);
+@@ -3907,9 +3907,9 @@ Debugger::drainTraceLogger(JSContext* cx, unsigned argc, Value* vp)
+     size_t num;
+     TraceLoggerThread* logger = TraceLoggerForMainThread(cx->runtime());
+     bool lostEvents = logger->lostEvents(dbg->traceLoggerLastDrainedIteration,
+-                                         dbg->traceLoggerLastDrainedId);
++                                         dbg->traceLoggerLastDrainedSize);
+     EventEntry* events = logger->getEventsStartingAt(&dbg->traceLoggerLastDrainedIteration,
+-                                                     &dbg->traceLoggerLastDrainedId,
++                                                     &dbg->traceLoggerLastDrainedSize,
+                                                      &num);
+ 
+     RootedObject array(cx, NewDenseEmptyArray(cx));
+@@ -4002,10 +4002,10 @@ Debugger::drainTraceLoggerScriptCalls(JSContext* cx, unsigned argc, Value* vp)
+     size_t num;
+     TraceLoggerThread* logger = TraceLoggerForMainThread(cx->runtime());
+     bool lostEvents = logger->lostEvents(dbg->traceLoggerScriptedCallsLastDrainedIteration,
+-                                         dbg->traceLoggerScriptedCallsLastDrainedId);
++                                         dbg->traceLoggerScriptedCallsLastDrainedSize);
+     EventEntry* events = logger->getEventsStartingAt(
+                                          &dbg->traceLoggerScriptedCallsLastDrainedIteration,
+-                                         &dbg->traceLoggerScriptedCallsLastDrainedId,
++                                         &dbg->traceLoggerScriptedCallsLastDrainedSize,
+                                          &num);
+ 
+     RootedObject array(cx, NewDenseEmptyArray(cx));
+diff --git a/js/src/vm/Debugger.h b/js/src/vm/Debugger.h
+index 8cac36a..c92d685 100644
+--- a/js/src/vm/Debugger.h
++++ b/js/src/vm/Debugger.h
+@@ -314,10 +314,10 @@ class Debugger : private mozilla::LinkedListElement<Debugger>
+      * lost events.
+      */
+ #ifdef NIGHTLY_BUILD
+-    uint32_t traceLoggerLastDrainedId;
++    uint32_t traceLoggerLastDrainedSize;
+     uint32_t traceLoggerLastDrainedIteration;
+ #endif
+-    uint32_t traceLoggerScriptedCallsLastDrainedId;
++    uint32_t traceLoggerScriptedCallsLastDrainedSize;
+     uint32_t traceLoggerScriptedCallsLastDrainedIteration;
+ 
+     class FrameRange;
+diff --git a/js/src/vm/TraceLogging.cpp b/js/src/vm/TraceLogging.cpp
+index 6715b36..9766a6f 100644
+--- a/js/src/vm/TraceLogging.cpp
++++ b/js/src/vm/TraceLogging.cpp
+@@ -131,7 +131,7 @@ TraceLoggerThread::init()
+ {
+     if (!pointerMap.init())
+         return false;
+-    if (!extraTextId.init())
++    if (!textIdPayloads.init())
+         return false;
+     if (!events.init())
+         return false;
+@@ -185,10 +185,10 @@ TraceLoggerThread::~TraceLoggerThread()
+         graph = nullptr;
+     }
+ 
+-    for (TextIdHashMap::Range r = extraTextId.all(); !r.empty(); r.popFront())
+-        js_delete(r.front().value());
+-    extraTextId.finish();
+-    pointerMap.finish();
++    if (textIdPayloads.initialized()) {
++        for (TextIdHashMap::Range r = textIdPayloads.all(); !r.empty(); r.popFront())
++            js_delete(r.front().value());
++    }
+ }
+ 
+ bool
+@@ -287,7 +287,7 @@ TraceLoggerThread::eventText(uint32_t id)
+     if (id < TraceLogger_Last)
+         return TLTextIdString(static_cast<TraceLoggerTextId>(id));
+ 
+-    TextIdHashMap::Ptr p = extraTextId.lookup(id);
++    TextIdHashMap::Ptr p = textIdPayloads.lookup(id);
+     MOZ_ASSERT(p);
+ 
+     return p->value()->string();
+@@ -341,13 +341,15 @@ TraceLoggerThread::extractScriptDetails(uint32_t textId, const char** filename,
+ TraceLoggerEventPayload*
+ TraceLoggerThread::getOrCreateEventPayload(TraceLoggerTextId textId)
+ {
+-    TextIdHashMap::AddPtr p = extraTextId.lookupForAdd(textId);
+-    if (p)
++    TextIdHashMap::AddPtr p = textIdPayloads.lookupForAdd(textId);
++    if (p) {
++        MOZ_ASSERT(p->value()->textId() == textId); // Sanity check.
+         return p->value();
++    }
+ 
+     TraceLoggerEventPayload* payload = js_new<TraceLoggerEventPayload>(textId, (char*)nullptr);
+ 
+-    if (!extraTextId.add(p, textId, payload))
++    if (!textIdPayloads.add(p, textId, payload))
+         return nullptr;
+ 
+     return payload;
+@@ -357,8 +359,10 @@ TraceLoggerEventPayload*
+ TraceLoggerThread::getOrCreateEventPayload(const char* text)
+ {
+     PointerHashMap::AddPtr p = pointerMap.lookupForAdd((const void*)text);
+-    if (p)
++    if (p) {
++        MOZ_ASSERT(p->value()->textId() < nextTextId); // Sanity check.
+         return p->value();
++    }
+ 
+     size_t len = strlen(text);
+     char* str = js_pod_malloc<char>(len + 1);
+@@ -369,7 +373,7 @@ TraceLoggerThread::getOrCreateEventPayload(const char* text)
+     MOZ_ASSERT(ret == len);
+     MOZ_ASSERT(strlen(str) == len);
+ 
+-    uint32_t textId = extraTextId.count() + TraceLogger_Last;
++    uint32_t textId = nextTextId;
+ 
+     TraceLoggerEventPayload* payload = js_new<TraceLoggerEventPayload>(textId, str);
+     if (!payload) {
+@@ -377,17 +381,19 @@ TraceLoggerThread::getOrCreateEventPayload(const char* text)
+         return nullptr;
+     }
+ 
+-    if (!extraTextId.putNew(textId, payload)) {
++    if (!textIdPayloads.putNew(textId, payload)) {
+         js_delete(payload);
+         return nullptr;
+     }
+ 
+-    if (!pointerMap.add(p, text, payload))
+-        return nullptr;
+-
+     if (graph.get())
+         graph->addTextId(textId, str);
+ 
++    nextTextId++;
++
++    if (!pointerMap.add(p, text, payload))
++        return nullptr;
++
+     return payload;
+ }
+ 
+@@ -407,9 +413,14 @@ TraceLoggerThread::getOrCreateEventPayload(TraceLoggerTextId type, const char* f
+     if (!traceLoggerState->isTextIdEnabled(type))
+         return getOrCreateEventPayload(type);
+ 
+-    PointerHashMap::AddPtr p = pointerMap.lookupForAdd(ptr);
+-    if (p)
+-        return p->value();
++    PointerHashMap::AddPtr p;
++    if (ptr) {
++        p = pointerMap.lookupForAdd(ptr);
++        if (p) {
++            MOZ_ASSERT(p->value()->textId() < nextTextId); // Sanity check.
++            return p->value();
++        }
++    }
+ 
+     // Compute the length of the string to create.
+     size_t lenFilename = strlen(filename);
+@@ -428,24 +439,28 @@ TraceLoggerThread::getOrCreateEventPayload(TraceLoggerTextId type, const char* f
+     MOZ_ASSERT(ret == len);
+     MOZ_ASSERT(strlen(str) == len);
+ 
+-    uint32_t textId = extraTextId.count() + TraceLogger_Last;
++    uint32_t textId = nextTextId;
+     TraceLoggerEventPayload* payload = js_new<TraceLoggerEventPayload>(textId, str);
+     if (!payload) {
+         js_free(str);
+         return nullptr;
+     }
+ 
+-    if (!extraTextId.putNew(textId, payload)) {
++    if (!textIdPayloads.putNew(textId, payload)) {
+         js_delete(payload);
+         return nullptr;
+     }
+ 
+-    if (!pointerMap.add(p, ptr, payload))
+-        return nullptr;
+-
+     if (graph.get())
+         graph->addTextId(textId, str);
+ 
++    nextTextId++;
++
++    if (ptr) {
++        if (!pointerMap.add(p, ptr, payload))
++            return nullptr;
++    }
++
+     return payload;
+ }
+ 
+@@ -453,14 +468,14 @@ TraceLoggerEventPayload*
+ TraceLoggerThread::getOrCreateEventPayload(TraceLoggerTextId type, JSScript* script)
+ {
+     return getOrCreateEventPayload(type, script->filename(), script->lineno(), script->column(),
+-                                   script);
++                                   nullptr);
+ }
+ 
+ TraceLoggerEventPayload*
+ TraceLoggerThread::getOrCreateEventPayload(TraceLoggerTextId type,
+                                            const JS::ReadOnlyCompileOptions& script)
+ {
+-    return getOrCreateEventPayload(type, script.filename(), script.lineno, script.column, &script);
++    return getOrCreateEventPayload(type, script.filename(), script.lineno, script.column, nullptr);
+ }
+ 
+ void
+@@ -485,7 +500,7 @@ TraceLoggerThread::startEvent(uint32_t id)
+     if (!traceLoggerState->isTextIdEnabled(id))
+        return;
+ 
+-    logTimestamp(id);
++    log(id);
+ }
+ 
+ void
+@@ -510,7 +525,7 @@ TraceLoggerThread::stopEvent(uint32_t id)
+     if (!traceLoggerState->isTextIdEnabled(id))
+         return;
+ 
+-    logTimestamp(TraceLogger_Stop);
++    log(TraceLogger_Stop);
+ }
+ 
+ void
+@@ -522,23 +537,57 @@ TraceLoggerThread::logTimestamp(TraceLoggerTextId id)
+ void
+ TraceLoggerThread::logTimestamp(uint32_t id)
+ {
++    MOZ_ASSERT(id > TraceLogger_LastTreeItem && id < TraceLogger_Last);
++    log(id);
++}
++
++void
++TraceLoggerThread::log(uint32_t id)
++{
+     if (enabled == 0)
+         return;
+ 
+     MOZ_ASSERT(traceLoggerState);
+-    if (!events.ensureSpaceBeforeAdd()) {
++
++    // We request for 3 items to add, since if we don't have enough room
++    // we record the time it took to make more place. To log this information
++    // we need 2 extra free entries.
++    if (!events.hasSpaceForAdd(3)) {
+         uint64_t start = rdtsc() - traceLoggerState->startupTime;
+ 
+-        if (graph.get())
+-            graph->log(events);
++        if (!events.ensureSpaceBeforeAdd(3)) {
++            if (graph.get())
++                graph->log(events);
++
++            iteration_++;
++            events.clear();
++
++            // Remove the item in the pointerMap for which the payloads
++            // have no uses anymore
++            for (PointerHashMap::Enum e(pointerMap); !e.empty(); e.popFront()) {
++                if (e.front().value()->uses() != 0)
++                    continue;
++
++                TextIdHashMap::Ptr p = textIdPayloads.lookup(e.front().value()->textId());
++                MOZ_ASSERT(p);
++                textIdPayloads.remove(p);
++
++                e.removeFront();
++            }
+ 
+-        iteration_++;
+-        events.clear();
++            // Free all payloads that have no uses anymore.
++            for (TextIdHashMap::Enum e(textIdPayloads); !e.empty(); e.popFront()) {
++                if (e.front().value()->uses() == 0) {
++                    js_delete(e.front().value());
++                    e.removeFront();
++                }
++            }
++        }
+ 
+         // Log the time it took to flush the events as being from the
+         // Tracelogger.
+         if (graph.get()) {
+-            MOZ_ASSERT(events.capacity() > 2);
++            MOZ_ASSERT(events.hasSpaceForAdd(2));
+             EventEntry& entryStart = events.pushUninitialized();
+             entryStart.time = start;
+             entryStart.textId = TraceLogger_Internal;
+@@ -548,13 +597,6 @@ TraceLoggerThread::logTimestamp(uint32_t id)
+             entryStop.textId = TraceLogger_Stop;
+         }
+ 
+-        // Free all TextEvents that have no uses anymore.
+-        for (TextIdHashMap::Enum e(extraTextId); !e.empty(); e.popFront()) {
+-            if (e.front().value()->uses() == 0) {
+-                js_delete(e.front().value());
+-                e.removeFront();
+-            }
+-        }
+     }
+ 
+     uint64_t time = rdtsc() - traceLoggerState->startupTime;
+@@ -956,3 +998,16 @@ TraceLoggerEvent::~TraceLoggerEvent()
+     if (payload_)
+         payload_->release();
+ }
++
++TraceLoggerEvent&
++TraceLoggerEvent::operator=(const TraceLoggerEvent& other)
++{
++    if (hasPayload())
++        payload()->release();
++    if (other.hasPayload())
++        other.payload()->use();
++
++    payload_ = other.payload_;
++
++    return *this;
++}
+diff --git a/js/src/vm/TraceLogging.h b/js/src/vm/TraceLogging.h
+index a124dcb..91a1eb0 100644
+--- a/js/src/vm/TraceLogging.h
++++ b/js/src/vm/TraceLogging.h
+@@ -110,6 +110,9 @@ class TraceLoggerEvent {
+     bool hasPayload() const {
+         return !!payload_;
+     }
++
++    TraceLoggerEvent& operator=(const TraceLoggerEvent& other);
++    TraceLoggerEvent(const TraceLoggerEvent& event) = delete;
+ };
+ 
+ /**
+@@ -130,6 +133,10 @@ class TraceLoggerEventPayload {
+         uses_(0)
+     { }
+ 
++    ~TraceLoggerEventPayload() {
++        MOZ_ASSERT(uses_ == 0);
++    }
++
+     uint32_t textId() {
+         return textId_;
+     }
+@@ -166,7 +173,8 @@ class TraceLoggerThread
+     mozilla::UniquePtr<TraceLoggerGraph> graph;
+ 
+     PointerHashMap pointerMap;
+-    TextIdHashMap extraTextId;
++    TextIdHashMap textIdPayloads;
++    uint32_t nextTextId;
+ 
+     ContinuousSpace<EventEntry> events;
+ 
+@@ -181,6 +189,7 @@ class TraceLoggerThread
+       : enabled(0),
+         failed(false),
+         graph(),
++        nextTextId(TraceLogger_Last),
+         iteration_(0),
+         top(nullptr)
+     { }
+@@ -195,22 +204,22 @@ class TraceLoggerThread
+     bool enable(JSContext* cx);
+     bool disable();
+ 
+-    // Given the previous iteration and lastEntryId, return an array of events
++    // Given the previous iteration and size, return an array of events
+     // (there could be lost events). At the same time update the iteration and
+-    // lastEntry and gives back how many events there are.
+-    EventEntry* getEventsStartingAt(uint32_t* lastIteration, uint32_t* lastEntryId, size_t* num) {
++    // size and gives back how many events there are.
++    EventEntry* getEventsStartingAt(uint32_t* lastIteration, uint32_t* lastSize, size_t* num) {
+         EventEntry* start;
+         if (iteration_ == *lastIteration) {
+-            MOZ_ASSERT(events.lastEntryId() >= *lastEntryId);
+-            *num = events.lastEntryId() - *lastEntryId;
+-            start = events.data() + *lastEntryId + 1;
++            MOZ_ASSERT(*lastSize <= events.size());
++            *num = events.size() - *lastSize;
++            start = events.data() + *lastSize;
+         } else {
+-            *num = events.lastEntryId() + 1;
++            *num = events.size();
+             start = events.data();
+         }
+ 
+         *lastIteration = iteration_;
+-        *lastEntryId = events.lastEntryId();
++        *lastSize = events.size();
+         return start;
+     }
+ 
+@@ -220,16 +229,16 @@ class TraceLoggerThread
+                               const char** lineno, size_t* lineno_len, const char** colno,
+                               size_t* colno_len);
+ 
+-    bool lostEvents(uint32_t lastIteration, uint32_t lastEntryId) {
++    bool lostEvents(uint32_t lastIteration, uint32_t lastSize) {
+         // If still logging in the same iteration, there are no lost events.
+         if (lastIteration == iteration_) {
+-            MOZ_ASSERT(lastEntryId <= events.lastEntryId());
++            MOZ_ASSERT(lastSize <= events.size());
+             return false;
+         }
+ 
+-        // When proceeded to the next iteration and lastEntryId points to
+-        // the maximum capacity there are no logs that are lost.
+-        if (lastIteration + 1 == iteration_ && lastEntryId == events.capacity())
++        // If we are in a consecutive iteration we are only sure we didn't lose any events,
++        // when the lastSize equals the maximum size 'events' can get.
++        if (lastIteration == iteration_ - 1 && lastSize == events.maxSize())
+             return false;
+ 
+         return true;
+@@ -268,6 +277,7 @@ class TraceLoggerThread
+     void stopEvent(uint32_t id);
+   private:
+     void stopEvent();
++    void log(uint32_t id);
+ 
+   public:
+     static unsigned offsetOfEnabled() {
+diff --git a/js/src/vm/TraceLoggingGraph.cpp b/js/src/vm/TraceLoggingGraph.cpp
+index d1b7f2e..a4eb273 100644
+--- a/js/src/vm/TraceLoggingGraph.cpp
++++ b/js/src/vm/TraceLoggingGraph.cpp
+@@ -276,7 +276,7 @@ TraceLoggerGraph::flush()
+         if (bytesWritten < tree.size())
+             return false;
+ 
+-        treeOffset += tree.lastEntryId();
++        treeOffset += tree.size();
+         tree.clear();
+     }
+ 
+@@ -359,7 +359,7 @@ TraceLoggerGraph::startEventInternal(uint32_t id, uint64_t timestamp)
+ 
+     if (parent.lastChildId() == 0) {
+         MOZ_ASSERT(!entry.hasChildren());
+-        MOZ_ASSERT(parent.treeId() == tree.lastEntryId() + treeOffset);
++        MOZ_ASSERT(parent.treeId() == treeOffset + tree.size() - 1);
+ 
+         if (!updateHasChildren(parent.treeId()))
+             return false;
+diff --git a/js/src/vm/TraceLoggingTypes.h b/js/src/vm/TraceLoggingTypes.h
+index f1c9d0c..10b76d6 100644
+--- a/js/src/vm/TraceLoggingTypes.h
++++ b/js/src/vm/TraceLoggingTypes.h
+@@ -21,7 +21,6 @@
+     _(Internal)                                       \
+     _(Interpreter)                                    \
+     _(InlinedScripts)                                 \
+-    _(Invalidation)                                   \
+     _(IonCompilation)                                 \
+     _(IonCompilationPaused)                           \
+     _(IonLinking)                                     \
+@@ -60,6 +59,7 @@
+ 
+ #define TRACELOGGER_LOG_ITEMS(_)                      \
+     _(Bailout)                                        \
++    _(Invalidation)                                   \
+     _(Disable)                                        \
+     _(Enable)                                         \
+     _(Stop)
+@@ -130,6 +130,9 @@ class ContinuousSpace {
+     uint32_t size_;
+     uint32_t capacity_;
+ 
++    // The maximum amount of ram memory a continuous space structure can take (in bytes).
++    static const uint32_t LIMIT = 200 * 1024 * 1024;
++
+   public:
+     ContinuousSpace ()
+      : data_(nullptr)
+@@ -151,6 +154,10 @@ class ContinuousSpace {
+         data_ = nullptr;
+     }
+ 
++    static uint32_t maxSize() {
++        return LIMIT / sizeof(T);
++    }
++
+     T* data() {
+         return data_;
+     }
+@@ -187,11 +194,14 @@ class ContinuousSpace {
+         if (hasSpaceForAdd(count))
+             return true;
+ 
++        // Limit the size of a continuous buffer.
++        if (size_ + count > maxSize())
++            return false;
++
+         uint32_t nCapacity = capacity_ * 2;
+-        if (size_ + count > nCapacity)
+-            nCapacity = size_ + count;
+-        T* entries = (T*) js_realloc(data_, nCapacity * sizeof(T));
++        nCapacity = (nCapacity < maxSize()) ? nCapacity : maxSize();
+ 
++        T* entries = (T*) js_realloc(data_, nCapacity * sizeof(T));
+         if (!entries)
+             return false;
+