[lldb] Unify CalculateMD5 return types

[Awfa]

This is a retake of #90921 which got reverted because I forgot to modify the CalculateMD5 unit test I had added in #88812

The prior failing build is here: https://lab.llvm.org/buildbot/#/builders/68/builds/73622
To make sure this error doesn't happen, I ran ninja ProcessGdbRemoteTests and then executed the resulting test binary and observed the CalculateMD5 test passed.

Overview

In my previous PR: #88812, @JDevlieghere suggested to match return types of the various calculate md5 functions.

This PR achieves that by changing the various calculate md5 functions to return llvm::ErrorOr<llvm::MD5::MD5Result>.
 
The suggestion was to go for std::optional<> but I opted for llvm::ErrorOr<> because local calculate md5 was already possibly returning ErrorOr.

To make sure I didn't break the md5 calculation functionality, I ran some tests for the gdb remote client, and things seem to work.

Testing

1. Remote file doesn't exist
   

2. Remote file differs
   

3. Remote file matches
   

Test gaps

Unfortunately, I had to modify lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp and I can't test the changes there. Hopefully, the existing test suite / code review from whomever is reading this will catch any issues.

[Awfa]

@JDevlieghere , do you know if there's a way to run buildbot on a merge of this PR and main branch - just to validate the build/tests work before this merge?

The llvm contributing guide says this is normal workflow - but I worry since I am using a lot of the maintainers' time to merge / revert the changes for me since I don't have write access.

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff d129ea8d2fa347e63deec0791faf389b84f20ce1 44223e9a62d116c50b52985ab944a5e2d48de95a -- lldb/include/lldb/Target/Platform.h lldb/include/lldb/Target/RemoteAwarePlatform.h lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.cpp lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.h lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h lldb/source/Target/Platform.cpp lldb/source/Target/RemoteAwarePlatform.cpp lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp

View the diff from clang-format here.

diff --git a/lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp b/lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp
index 6dcf7ef3ea..24111396b0 100644
--- a/lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp
+++ b/lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp
@@ -595,9 +595,8 @@ TEST_F(GDBRemoteCommunicationClientTest, WriteMemoryTags) {
 
 TEST_F(GDBRemoteCommunicationClientTest, CalculateMD5) {
   FileSpec file_spec("/foo/bar", FileSpec::Style::posix);
-  std::future<ErrorOr<MD5::MD5Result>> async_result = std::async(std::launch::async, [&] {
-    return client.CalculateMD5(file_spec);
-  });
+  std::future<ErrorOr<MD5::MD5Result>> async_result = std::async(
+      std::launch::async, [&] { return client.CalculateMD5(file_spec); });
 
   lldb_private::StreamString stream;
   stream.PutCString("vFile:MD5:");

[Awfa]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:
View the diff from clang-format here.

This formatter alert is outdated - by the time this arrived, my PR had the issue fixed already.

[JDevlieghere]

@JDevlieghere , do you know if there's a way to run buildbot on a merge of this PR and main branch - just to validate the build/tests work before this merge?

Not that I know. When failures are macOS specific I'm happy to apply a PR locally and run the test suite and other folks with specific configurations might do the same, but that's about all I can think of.

The llvm contributing guide says this is normal workflow - but I worry since I am using a lot of the maintainers' time to merge / revert the changes for me since I don't have write access.

No worries, it's totally normal and we're happy to help with that!

[Awfa]

@JDevlieghere , do you know if there's a way to run buildbot on a merge of this PR and main branch - just to validate the build/tests work before this merge?

Not that I know. When failures are macOS specific I'm happy to apply a PR locally and run the test suite and other folks with specific configurations might do the same, but that's about all I can think of.

The llvm contributing guide says this is normal workflow - but I worry since I am using a lot of the maintainers' time to merge / revert the changes for me since I don't have write access.

No worries, it's totally normal and we're happy to help with that!

Can I ask you merge this for me? Hopefully no reverts this time :)