[lldb] Print better diagnostics for user expressions and modules

Summary:
Currently our expression evaluators only prints very basic errors that are not very useful when writing complex expressions.

For example, in the expression below the user made a type error, but it's not clear from the diagnostic what went wrong:
```
(lldb) expr printf("Modulos are:", foobar%mo1, foobar%mo2, foobar%mo3)
error: invalid operands to binary expression ('int' and 'double')
```

This patch enables full Clang diagnostics in our expression evaluator. After this patch the diagnostics for the expression look like this:

```
(lldb) expr printf("Modulos are:", foobar%mo1, foobar%mo2, foobar%mo3)
error: <user expression 1>:1:54: invalid operands to binary expression ('int' and 'float')
printf("Modulos are:", foobar%mo1, foobar%mo2, foobar%mo3)
                                               ~~~~~~^~~~
```

To make this possible, we now emulate a user expression file within our diagnostics. This prevents that the user is exposed to
our internal wrapper code we inject.

Note that the diagnostics that refer to declarations from the debug information (e.g. 'note' diagnostics pointing to a called function)
will not be improved by this as they don't have any source locations associated with them, so caret or line printing isn't possible.
We instead just suppress these diagnostics as we already do with warnings as they would otherwise just be a context message
without any context (and the original diagnostic in the user expression should be enough to explain the issue).

Fixes rdar://24306342

Reviewers: JDevlieghere, aprantl, shafik, #lldb

Reviewed By: JDevlieghere, #lldb

Subscribers: usaxena95, davide, jingham, aprantl, arphaman, kadircet, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D65646

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@372203 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticOptions.def b/include/clang/Basic/DiagnosticOptions.def
index baafd7ac723f6b83761e68a2697b5a27ad4b3452..6d1a1af92821b744b82f28626cbc8c7388d531dc 100644 (file)
--- a/include/clang/Basic/DiagnosticOptions.def
+++ b/include/clang/Basic/DiagnosticOptions.def
@@ -49,6 +49,7 @@ DIAGOPT(Pedantic, 1, 0)         /// -pedantic
 DIAGOPT(PedanticErrors, 1, 0)   /// -pedantic-errors
 DIAGOPT(ShowColumn, 1, 1)       /// Show column number on diagnostics.
 DIAGOPT(ShowLocation, 1, 1)     /// Show source location information.
+DIAGOPT(ShowLevel, 1, 1)        /// Show diagnostic level.
 DIAGOPT(AbsolutePath, 1, 0)     /// Use absolute paths.
 DIAGOPT(ShowCarets, 1, 1)       /// Show carets in diagnostics.
 DIAGOPT(ShowFixits, 1, 1)       /// Show fixit information.

diff --git a/lib/Frontend/TextDiagnostic.cpp b/lib/Frontend/TextDiagnostic.cpp
index d6e75a9180cf54d2ee0e6ae938a3f972a45b8f30..7bb6c5b74d5f60bbdbbace1c825d6bbf5dcae5e7 100644 (file)
--- a/lib/Frontend/TextDiagnostic.cpp
+++ b/lib/Frontend/TextDiagnostic.cpp
@@ -683,8 +683,9 @@ void TextDiagnostic::emitDiagnosticMessage(
   if (DiagOpts->ShowColors)
     OS.resetColor();
 
-  printDiagnosticLevel(OS, Level, DiagOpts->ShowColors,
-                       DiagOpts->CLFallbackMode);
+  if (DiagOpts->ShowLevel)
+    printDiagnosticLevel(OS, Level, DiagOpts->ShowColors,
+                         DiagOpts->CLFallbackMode);
   printDiagnosticMessage(OS,
                          /*IsSupplemental*/ Level == DiagnosticsEngine::Note,
                          Message, OS.tell() - StartOfLocationInfo,