[lldb] Turn lldb_private::Status into a value type. (#106163)

This patch removes all of the Set.* methods from Status.

This cleanup is part of a series of patches that make it harder use the
anti-pattern of keeping a long-lives Status object around and updating
it while dropping any errors it contains on the floor.

This patch is largely NFC, the more interesting next steps this enables
is to:
1. remove Status.Clear()
2. assert that Status::operator=() never overwrites an error
3. remove Status::operator=()

Note that step (2) will bring 90% of the benefits for users, and step
(3) will dramatically clean up the error handling code in various
places. In the end my goal is to convert all APIs that are of the form

`    ResultTy DoFoo(Status& error)
`
to

`    llvm::Expected<ResultTy> DoFoo()
`
How to read this patch?

The interesting changes are in Status.h and Status.cpp, all other
changes are mostly

` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git
grep -l SetErrorString lldb/source)
`
plus the occasional manual cleanup.

1 files changed, 8 insertions, 8 deletions

diff --git a/lldb/source/Commands/CommandObjectMemory.cpp b/lldb/source/Commands/CommandObjectMemory.cpp
index baf5d91..f93081d3 100644
--- a/lldb/source/Commands/CommandObjectMemory.cpp
+++ b/lldb/source/Commands/CommandObjectMemory.cpp
@@ -68,7 +68,7 @@ public:
     case 'l':
       error = m_num_per_line.SetValueFromString(option_value);
       if (m_num_per_line.GetCurrentValue() == 0)
-        error.SetErrorStringWithFormat(
+        error = Status::FromErrorStringWithFormat(
             "invalid value for --num-per-line option '%s'",
             option_value.str().c_str());
       break;
@@ -176,7 +176,7 @@ public:
     case eFormatBytesWithASCII:
       if (byte_size_option_set) {
         if (byte_size_value > 1)
-          error.SetErrorStringWithFormat(
+          error = Status::FromErrorStringWithFormat(
               "display format (bytes/bytes with ASCII) conflicts with the "
               "specified byte size %" PRIu64 "\n"
               "\tconsider using a different display format or don't specify "
@@ -913,12 +913,12 @@ public:
 
       case 'c':
         if (m_count.SetValueFromString(option_value).Fail())
-          error.SetErrorString("unrecognized value for count");
+          error = Status::FromErrorString("unrecognized value for count");
         break;
 
       case 'o':
         if (m_offset.SetValueFromString(option_value).Fail())
-          error.SetErrorString("unrecognized value for dump-offset");
+          error = Status::FromErrorString("unrecognized value for dump-offset");
         break;
 
       default:
@@ -1150,16 +1150,16 @@ public:
         FileSystem::Instance().Resolve(m_infile);
         if (!FileSystem::Instance().Exists(m_infile)) {
           m_infile.Clear();
-          error.SetErrorStringWithFormat("input file does not exist: '%s'",
-                                         option_value.str().c_str());
+          error = Status::FromErrorStringWithFormat(
+              "input file does not exist: '%s'", option_value.str().c_str());
         }
         break;
 
       case 'o': {
         if (option_value.getAsInteger(0, m_infile_offset)) {
           m_infile_offset = 0;
-          error.SetErrorStringWithFormat("invalid offset string '%s'",
-                                         option_value.str().c_str());
+          error = Status::FromErrorStringWithFormat(
+              "invalid offset string '%s'", option_value.str().c_str());
         }
       } break;