Add a DiagnosticManager replace error streams in the expression parser.

We want to do a better job presenting errors that occur when evaluating
expressions. Key to this effort is getting away from a model where all
errors are spat out onto a stream where the client has to take or leave
all of them.

To this end, this patch adds a new class, DiagnosticManager, which
contains errors produced by the compiler or by LLDB as an expression
is created. The DiagnosticManager can dump itself to a log as well as
to a string. Clients will (in the future) be able to filter out the
errors they're interested in by ID or present subsets of these errors
to the user.

This patch is not intended to change the *users* of errors - only to
thread DiagnosticManagers to all the places where streams are used. I
also attempt to standardize our use of errors a bit, removing trailing
newlines and making clients omit 'error:', 'warning:' etc. and instead
pass the Severity flag.

The patch is testsuite-neutral, with modifications to one part of the
MI tests because it relied on "error: error:" being erroneously
printed. This patch fixes the MI variable handling and the testcase.

<rdar://problem/22864976>

llvm-svn: 263859

1 files changed, 27 insertions, 18 deletions

diff --git a/lldb/source/Plugins/SystemRuntime/MacOSX/AppleGetQueuesHandler.cpp b/lldb/source/Plugins/SystemRuntime/MacOSX/AppleGetQueuesHandler.cpp
index 3370b3257a2..e005d500e0c 100644
--- a/lldb/source/Plugins/SystemRuntime/MacOSX/AppleGetQueuesHandler.cpp
+++ b/lldb/source/Plugins/SystemRuntime/MacOSX/AppleGetQueuesHandler.cpp
@@ -18,6 +18,7 @@
 #include "lldb/Core/Module.h"
 #include "lldb/Core/StreamString.h"
 #include "lldb/Core/Value.h"
+#include "lldb/Expression/DiagnosticManager.h"
 #include "lldb/Expression/FunctionCaller.h"
 #include "lldb/Expression/UtilityFunction.h"
 #include "lldb/Symbol/ClangASTContext.h"
@@ -146,12 +147,12 @@ AppleGetQueuesHandler::Detach ()
 lldb::addr_t
 AppleGetQueuesHandler::SetupGetQueuesFunction (Thread &thread, ValueList &get_queues_arglist)
 {
-    ExecutionContext exe_ctx (thread.shared_from_this());
+    ExecutionContext exe_ctx(thread.shared_from_this());
     Address impl_code_address;
-    StreamString errors;
-    Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME));
+    DiagnosticManager diagnostics;
+    Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME));
     lldb::addr_t args_addr = LLDB_INVALID_ADDRESS;
-    
+
     FunctionCaller *get_queues_caller = nullptr;
 
     // Scope for mutex locker:
@@ -175,11 +176,14 @@ AppleGetQueuesHandler::SetupGetQueuesFunction (Thread &thread, ValueList &get_qu
                         log->Printf ("Failed to get UtilityFunction for queues introspection: %s.", error.AsCString());
                     return args_addr;
                 }
-                
-                if (!m_get_queues_impl_code_up->Install(errors, exe_ctx))
+
+                if (!m_get_queues_impl_code_up->Install(diagnostics, exe_ctx))
                 {
                     if (log)
-                        log->Printf ("Failed to install queues introspection: %s.", errors.GetData());
+                    {
+                        log->Printf("Failed to install queues introspection");
+                        diagnostics.Dump(log);
+                    }
                     m_get_queues_impl_code_up.reset();
                     return args_addr;
                 }
@@ -187,12 +191,14 @@ AppleGetQueuesHandler::SetupGetQueuesFunction (Thread &thread, ValueList &get_qu
             else
             {
                 if (log)
+                {
                     log->Printf("No queues introspection code found.");
-                errors.Printf ("No queues introspection code found.");
+                    diagnostics.Dump(log);
+                }
                 return LLDB_INVALID_ADDRESS;
             }
         }
-        
+
         // Next make the runner function for our implementation utility function.
         ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext();
         CompilerType get_queues_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
@@ -207,20 +213,23 @@ AppleGetQueuesHandler::SetupGetQueuesFunction (Thread &thread, ValueList &get_qu
             return args_addr;
         }
     }
-    
-    errors.Clear();
-    
+
+    diagnostics.Clear();
+
     // Now write down the argument values for this particular call.  This looks like it might be a race condition
     // if other threads were calling into here, but actually it isn't because we allocate a new args structure for
     // this call by passing args_addr = LLDB_INVALID_ADDRESS...
 
-    if (!get_queues_caller->WriteFunctionArguments (exe_ctx, args_addr, get_queues_arglist, errors))
+    if (!get_queues_caller->WriteFunctionArguments(exe_ctx, args_addr, get_queues_arglist, diagnostics))
     {
         if (log)
-            log->Printf ("Error writing get-queues function arguments: \"%s\".", errors.GetData());
+        {
+            log->Printf("Error writing get-queues function arguments.");
+            diagnostics.Dump(log);
+        }
         return args_addr;
     }
-        
+
     return args_addr;
 }
 
@@ -332,10 +341,10 @@ AppleGetQueuesHandler::GetCurrentQueues (Thread &thread, addr_t page_to_free, ui
         return return_value;
     }
 
-    StreamString errors;
+    DiagnosticManager diagnostics;
     ExecutionContext exe_ctx;
     EvaluateExpressionOptions options;
-    options.SetUnwindOnError (true);
+    options.SetUnwindOnError(true);
     options.SetIgnoreBreakpoints (true);
     options.SetStopOthers (true);
     options.SetTimeoutUsec(500000);
@@ -344,7 +353,7 @@ AppleGetQueuesHandler::GetCurrentQueues (Thread &thread, addr_t page_to_free, ui
 
     ExpressionResults func_call_ret;
     Value results;
-    func_call_ret =  get_queues_caller->ExecuteFunction (exe_ctx, &args_addr, options, errors, results);
+    func_call_ret = get_queues_caller->ExecuteFunction(exe_ctx, &args_addr, options, diagnostics, results);
     if (func_call_ret != eExpressionCompleted || !error.Success())
     {
         if (log)