[lldb] Apply KeyValueExtractorGDBRemote to qProcessInfo

[DavidSpickett]

Summary

The original logic is retained.

Unlike qHostInfo, qProcessInfo does not check whether
at least one key was parsed correctly. This allowed
me to move a lot of the Get calls next to where the
result is used.

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp

 //===-- GDBRemoteCommunicationClient.cpp ----------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
if (error)
       return error;
   }
   return -1;
 }
 
 bool GDBRemoteCommunicationClient::DecodeProcessInfoResponse(
     StringExtractorGDBRemote &response, ProcessInstanceInfo &process_info) {
   if (response.IsNormalResponse()) {
-    llvm::StringRef name;
-    llvm::StringRef value;
-    StringExtractor extractor;
+    KeyValueExtractorGDBRemote extractor(response);
 
-    uint32_t cpu = LLDB_INVALID_CPUTYPE;
-    uint32_t sub = 0;
-    std::string vendor;
-    std::string os_type;
+    process_info.SetProcessID(
+        extractor.GetWithDefault<lldb::pid_t>("pid", LLDB_INVALID_PROCESS_ID));
+    process_info.SetParentProcessID(
+        extractor.GetWithDefault<lldb::pid_t>("ppid", LLDB_INVALID_PROCESS_ID));
+    process_info.SetUserID(
+        extractor.GetWithDefault<uint32_t>("uid", UINT32_MAX));
+    process_info.SetEffectiveUserID(
+        extractor.GetWithDefault<uint32_t>("euid", UINT32_MAX));
+    process_info.SetGroupID(
+        extractor.GetWithDefault<uint32_t>("gid", UINT32_MAX));
+    process_info.SetEffectiveGroupID(
+        extractor.GetWithDefault<uint32_t>("egid", UINT32_MAX));
+
+    if (llvm::Optional<std::string> triple =
+            extractor.GetHexByteString("triple"))
+      process_info.GetArchitecture().SetTriple(triple->c_str());
 
-    while (response.GetNameColonValue(name, value)) {
-      if (name.equals("pid")) {
-        lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
-        value.getAsInteger(0, pid);
-        process_info.SetProcessID(pid);
-      } else if (name.equals("ppid")) {
-        lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
-        value.getAsInteger(0, pid);
-        process_info.SetParentProcessID(pid);
-      } else if (name.equals("uid")) {
-        uint32_t uid = UINT32_MAX;
-        value.getAsInteger(0, uid);
-        process_info.SetUserID(uid);
-      } else if (name.equals("euid")) {
-        uint32_t uid = UINT32_MAX;
-        value.getAsInteger(0, uid);
-        process_info.SetEffectiveUserID(uid);
-      } else if (name.equals("gid")) {
-        uint32_t gid = UINT32_MAX;
-        value.getAsInteger(0, gid);
-        process_info.SetGroupID(gid);
-      } else if (name.equals("egid")) {
-        uint32_t gid = UINT32_MAX;
-        value.getAsInteger(0, gid);
-        process_info.SetEffectiveGroupID(gid);
-      } else if (name.equals("triple")) {
-        StringExtractor extractor(value);
-        std::string triple;
-        extractor.GetHexByteString(triple);
-        process_info.GetArchitecture().SetTriple(triple.c_str());
-      } else if (name.equals("name")) {
-        StringExtractor extractor(value);
-        // The process name from ASCII hex bytes since we can't control the
-        // characters in a process name
-        std::string name;
-        extractor.GetHexByteString(name);
-        process_info.GetExecutableFile().SetFile(name, FileSpec::Style::native);
-      } else if (name.equals("args")) {
-        llvm::StringRef encoded_args(value), hex_arg;
+    if (llvm::Optional<std::string> name = extractor.GetHexByteString("name"))
+      process_info.GetExecutableFile().SetFile(*name, FileSpec::Style::native);
+
+    if (llvm::Optional<std::string> args = extractor.Get<std::string>("args")) {
+      llvm::StringRef encoded_args(*args), hex_arg;
 
-        bool is_arg0 = true;
-        while (!encoded_args.empty()) {
-          std::tie(hex_arg, encoded_args) = encoded_args.split('-');
-          std::string arg;
-          StringExtractor extractor(hex_arg);
-          if (extractor.GetHexByteString(arg) * 2 != hex_arg.size()) {
-            // In case of wrong encoding, we discard all the arguments
-            process_info.GetArguments().Clear();
-            process_info.SetArg0("");
-            break;
-          }
-          if (is_arg0)
-            process_info.SetArg0(arg);
-          else
-            process_info.GetArguments().AppendArgument(arg);
-          is_arg0 = false;
-        }
-      } else if (name.equals("cputype")) {
-        value.getAsInteger(0, cpu);
-      } else if (name.equals("cpusubtype")) {
-        value.getAsInteger(0, sub);
-      } else if (name.equals("vendor")) {
-        vendor = std::string(value);
-      } else if (name.equals("ostype")) {
-        os_type = std::string(value);
-      }
+      while (encoded_args.size()) {
     }
 
-    if (cpu != LLDB_INVALID_CPUTYPE && !vendor.empty() && !os_type.empty()) {
-      if (vendor == "apple") {
-        process_info.GetArchitecture().SetArchitecture(eArchTypeMachO, cpu,
+    llvm::Optional<uint32_t> cpu = extractor.Get<uint32_t>("cputype");
+    llvm::Optional<std::string> vendor = extractor.Get<std::string>("vendor");
+    llvm::Optional<std::string> os_type = extractor.Get<std::string>("ostype");
+
+    if (cpu && vendor && vendor->size() && os_type && os_type->size()) {
+      if (*vendor == "apple") {
+        uint32_t sub = extractor.GetWithDefault<uint32_t>("cpusubtype", 0);
+        process_info.GetArchitecture().SetArchitecture(eArchTypeMachO, *cpu,
                                                        sub);
         process_info.GetArchitecture().GetTriple().setVendorName(
-            llvm::StringRef(vendor));
+            llvm::StringRef(*vendor));
         process_info.GetArchitecture().GetTriple().setOSName(
-            llvm::StringRef(os_type));
+            llvm::StringRef(*os_type));
       }
     }
 
     if (process_info.GetProcessID() != LLDB_INVALID_PROCESS_ID)
       return true;
   }
   return false;
 }