Fix clang_analyzer failure (#8492)

Summary:
Previously, the following command:
```USE_CLANG=1 TEST_TMPDIR=/dev/shm/rocksdb OPT=-g make -j$(nproc) analyze```
was raising an error/warning the new_mem could potentially be a `nullptr`. This error appeared due to code changes from https://github.com/facebook/rocksdb/issues/8454, including an if-statement containing "`... && new_mem != nullptr && ...`", which made the analyzer believe that past this `if`-statement, a `new_mem==nullptr` was a possible scenario.
This code patch simply introduces `assert`s and removes this condition in the `if`-statement.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8492

Reviewed By: jay-zhuang

Differential Revision: D29571275

Pulled By: bjlemaire

fbshipit-source-id: 75d72246b70ebbbae7dea11ccb5778686d8bcbea
This commit is contained in:
Baptiste Lemaire 2021-07-06 18:47:59 -07:00 committed by Facebook GitHub Bot
parent df4197ca6e
commit 714ce5041d

View File

@ -2113,14 +2113,13 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
}
cfd->mem()->SetNextLogNumber(logfile_number_);
assert(new_mem != nullptr);
// By default, it is assumed that the 'old' memtable
// will be added to the Imm memtable list and will therefore
// contribute to the Imm memory footprint.
bool noImmMemoryContribution = false;
// If MemPurge activated, purge and delete current memtable.
if (immutable_db_options_.experimental_allow_mempurge &&
(new_mem != nullptr) &&
((cfd->GetFlushReason() == FlushReason::kOthers) ||
(cfd->GetFlushReason() == FlushReason::kManualFlush))) {
Status mempurge_s = MemPurge(cfd, new_mem);
@ -2135,9 +2134,8 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
noImmMemoryContribution = true;
} else {
// If mempurge failed, go back to regular mem->imm->flush workflow.
if (new_mem) {
delete new_mem;
}
assert(new_mem != nullptr);
delete new_mem;
SuperVersion* new_superversion =
context->superversion_context.new_superversion.release();
if (new_superversion != nullptr) {
@ -2145,6 +2143,7 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
}
SequenceNumber seq = versions_->LastSequence();
new_mem = cfd->ConstructNewMemtable(mutable_cf_options, seq);
assert(new_mem != nullptr);
context->superversion_context.NewSuperVersion();
cfd->imm()->Add(cfd->mem(), &context->memtables_to_free_);
}