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, 14 insertions, 11 deletions

diff --git a/lldb/source/Plugins/ExpressionParser/Go/GoUserExpression.cpp b/lldb/source/Plugins/ExpressionParser/Go/GoUserExpression.cpp
index 0b074f87c16..0457bfe0f32 100644
--- a/lldb/source/Plugins/ExpressionParser/Go/GoUserExpression.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Go/GoUserExpression.cpp
@@ -26,7 +26,6 @@
 // Project includes
 #include "GoUserExpression.h"
 
-#include "lldb/lldb-private.h"
 #include "lldb/Core/ConstString.h"
 #include "lldb/Core/DataBufferHeap.h"
 #include "lldb/Core/DataEncoder.h"
@@ -37,10 +36,11 @@
 #include "lldb/Core/StreamString.h"
 #include "lldb/Core/ValueObjectConstResult.h"
 #include "lldb/Core/ValueObjectRegister.h"
+#include "lldb/Expression/DiagnosticManager.h"
 #include "lldb/Expression/ExpressionVariable.h"
-#include "lldb/Symbol/TypeList.h"
 #include "lldb/Symbol/GoASTContext.h"
 #include "lldb/Symbol/SymbolFile.h"
+#include "lldb/Symbol/TypeList.h"
 #include "lldb/Symbol/VariableList.h"
 #include "lldb/Target/ExecutionContext.h"
 #include "lldb/Target/Process.h"
@@ -49,6 +49,7 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Target/ThreadPlan.h"
 #include "lldb/Target/ThreadPlanCallUserExpression.h"
+#include "lldb/lldb-private.h"
 
 #include "Plugins/ExpressionParser/Go/GoAST.h"
 #include "Plugins/ExpressionParser/Go/GoParser.h"
@@ -247,8 +248,9 @@ GoUserExpression::GoUserExpression(ExecutionContextScope &exe_scope, const char
 }
 
 bool
-GoUserExpression::Parse(Stream &error_stream, ExecutionContext &exe_ctx, lldb_private::ExecutionPolicy execution_policy,
-                        bool keep_result_in_memory, bool generate_debug_info)
+GoUserExpression::Parse(DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
+                        lldb_private::ExecutionPolicy execution_policy, bool keep_result_in_memory,
+                        bool generate_debug_info)
 {
     InstallContext(exe_ctx);
     m_interpreter.reset(new GoInterpreter(exe_ctx, GetUserText()));
@@ -256,15 +258,16 @@ GoUserExpression::Parse(Stream &error_stream, ExecutionContext &exe_ctx, lldb_pr
         return true;
     const char *error_cstr = m_interpreter->error().AsCString();
     if (error_cstr && error_cstr[0])
-        error_stream.Printf("error: %s\n", error_cstr);
+        diagnostic_manager.PutCString(eDiagnosticSeverityError, error_cstr);
     else
-        error_stream.Printf("error: expression can't be interpreted or run\n");
+        diagnostic_manager.Printf(eDiagnosticSeverityError, "expression can't be interpreted or run");
     return false;
 }
 
 lldb::ExpressionResults
-GoUserExpression::Execute(Stream &error_stream, ExecutionContext &exe_ctx, const EvaluateExpressionOptions &options,
-                          lldb::UserExpressionSP &shared_ptr_to_me, lldb::ExpressionVariableSP &result)
+GoUserExpression::Execute(DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
+                          const EvaluateExpressionOptions &options, lldb::UserExpressionSP &shared_ptr_to_me,
+                          lldb::ExpressionVariableSP &result)
 {
     Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP));
 
@@ -281,7 +284,7 @@ GoUserExpression::Execute(Stream &error_stream, ExecutionContext &exe_ctx, const
             if (log)
                 log->Printf("== [GoUserExpression::Evaluate] Expression may not run, but is not constant ==");
 
-            error_stream.Printf("expression needed to run but couldn't");
+            diagnostic_manager.PutCString(eDiagnosticSeverityError, "expression needed to run but couldn't");
 
             return execution_results;
         }
@@ -296,9 +299,9 @@ GoUserExpression::Execute(Stream &error_stream, ExecutionContext &exe_ctx, const
     {
         const char *error_cstr = err.AsCString();
         if (error_cstr && error_cstr[0])
-            error_stream.Printf("error: %s\n", error_cstr);
+            diagnostic_manager.PutCString(eDiagnosticSeverityError, error_cstr);
         else
-            error_stream.Printf("error: expression can't be interpreted or run\n");
+            diagnostic_manager.PutCString(eDiagnosticSeverityError, "expression can't be interpreted or run");
         return lldb::eExpressionDiscarded;
     }
     result.reset(new ExpressionVariable(ExpressionVariable::eKindGo));