[llvm] [CAS] Add OnDiskGraphDB and OnDiskKeyValueDB (PR #114102)

[Paul Osmialowski via llvm-commits]

pawosm-arm wrote:

Good news is that I've managed to reproduce it manually, outside of our CI, which means the problem isn't of CI-magical class:

```
******************** TEST 'LLVM-Unit :: CAS/./CASTests/1/22' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests-LLVM-Unit-20248-1-22.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=22 GTEST_SHARD_INDEX=1 /home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests
--

Note: This is test shard 2 of 22.
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from OnDiskCASTest
[ RUN      ] OnDiskCASTest.OnDiskGraphDBFaultInSingleNode
Failure value returned from cantFail wrapped call
data record span passed the end of the data pool
UNREACHABLE executed at /home/testuser/arm-toolchain/llvm/include/llvm/Support/Error.h:810!
 #0 0x0000000000466d30 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x466d30)
 #1 0x0000000000464918 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x0000e7c3b8b408f8 (linux-vdso.so.1+0x8f8)
 #3 0x0000e7c3b865b880 __pthread_kill_implementation (/lib64/libc.so.6+0x8b880)
 #4 0x0000e7c3b860aa40 gsignal (/lib64/libc.so.6+0x3aa40)
 #5 0x0000e7c3b85f5988 abort (/lib64/libc.so.6+0x25988)
 #6 0x000000000044f92c (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x44f92c)
 #7 0x0000000000494044 getContentFromHandle(llvm::cas::OnDiskDataAllocator const&, llvm::cas::ondisk::ObjectHandle) OnDiskGraphDB.cpp:0:0
 #8 0x000000000049413c llvm::cas::ondisk::OnDiskGraphDB::getObjectData(llvm::cas::ondisk::ObjectHandle) const (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x49413c)
 #9 0x000000000049883c llvm::cas::ondisk::OnDiskGraphDB::importSingleNode(llvm::cas::ondisk::ObjectID, llvm::cas::ondisk::ObjectHandle) (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x49883c)
#10 0x0000000000499be4 llvm::cas::ondisk::OnDiskGraphDB::faultInFromUpstream(llvm::cas::ondisk::ObjectID) (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x499be4)
#11 0x0000000000498cc4 llvm::cas::ondisk::OnDiskGraphDB::load(llvm::cas::ondisk::ObjectID) (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x498cc4)
#12 0x0000000000426a6c OnDiskCASTest_OnDiskGraphDBFaultInSingleNode_Test::TestBody() (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x426a6c)
#13 0x00000000004b74d0 testing::Test::Run() (.part.0) gtest-all.cc:0:0
#14 0x00000000004bdd70 testing::TestInfo::Run() (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x4bdd70)
#15 0x00000000004c8280 testing::TestSuite::Run() (.part.0) gtest-all.cc:0:0
#16 0x00000000004c8d64 testing::internal::UnitTestImpl::RunAllTests() (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x4c8d64)
#17 0x00000000004c92fc testing::UnitTest::Run() (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x4c92fc)
#18 0x0000000000408d70 main (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x408d70)
#19 0x0000e7c3b85f609c __libc_start_call_main (/lib64/libc.so.6+0x2609c)
#20 0x0000e7c3b85f617c __libc_start_main at GLIBC_2.17 (/lib64/libc.so.6+0x2617c)
#21 0x00000000004093f0 _start (/home/testuser/arm-toolchain/arm-software/linux/build/stage/bootstrap_compiler/unittests/CAS/./CASTests+0x4093f0)
```

The bad news, I still don't know what the root cause could be.


https://github.com/llvm/llvm-project/pull/114102