Refactor user/group name resolving code

Summary:
This creates an abstract base class called "UserIDResolver", which can
be implemented to provide user/group ID resolution capabilities for
various objects. Posix host implement a PosixUserIDResolver, which does
that using posix apis (getpwuid and friends).  PlatformGDBRemote
forwards queries over the gdb-remote link, etc. ProcessInstanceInfo
class is refactored to make use of this interface instead of taking a
platform pointer as an argument. The base resolver class already
implements caching and thread-safety, so implementations don't have to
worry about that.

The main motivating factor for this was to remove external dependencies
from the ProcessInstanceInfo class (so it can be put next to
ProcessLaunchInfo and friends), but it has other benefits too:
- ability to test the user name caching code
- ability to test ProcessInstanceInfo dumping code
- consistent interface for user/group resolution between Platform and
  Host classes.

Reviewers: zturner, clayborg, jingham

Subscribers: mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D58167

llvm-svn: 355323

1 files changed, 6 insertions, 6 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
index c7a4127d9d4..5bc0c25c587 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
@@ -436,10 +436,10 @@ GDBRemoteCommunicationServerCommon::Handle_qUserName(
   packet.SetFilePos(::strlen("qUserName:"));
   uint32_t uid = packet.GetU32(UINT32_MAX);
   if (uid != UINT32_MAX) {
-    std::string name;
-    if (HostInfo::LookupUserName(uid, name)) {
+    if (llvm::Optional<llvm::StringRef> name =
+            HostInfo::GetUserIDResolver().GetUserName(uid)) {
       StreamString response;
-      response.PutStringAsRawHex8(name);
+      response.PutStringAsRawHex8(*name);
       return SendPacketNoLock(response.GetString());
     }
   }
@@ -457,10 +457,10 @@ GDBRemoteCommunicationServerCommon::Handle_qGroupName(
   packet.SetFilePos(::strlen("qGroupName:"));
   uint32_t gid = packet.GetU32(UINT32_MAX);
   if (gid != UINT32_MAX) {
-    std::string name;
-    if (HostInfo::LookupGroupName(gid, name)) {
+    if (llvm::Optional<llvm::StringRef> name =
+            HostInfo::GetUserIDResolver().GetGroupName(gid)) {
       StreamString response;
-      response.PutStringAsRawHex8(name);
+      response.PutStringAsRawHex8(*name);
       return SendPacketNoLock(response.GetString());
     }
   }