lldb expression inline note prints "note: " twice

[DavidSpickett]

With this program:

int main()
{
    const int a = 0;
    return 0;
}

And this expression:

(lldb) p a=10
          ˄
          ╰─ error: cannot assign to variable 'a' with const-qualified type 'const int &'
note: note: variable 'a' declared const here

LLDB prints "note: " then "note: " again.

Also, "here" seems like it would be accompanied by some location but is not.

[llvmbot]

@llvm/issue-subscribers-lldb

Author: David Spickett (DavidSpickett)

With this program: ``` int main() { const int a = 0; return 0; } ``` And this expression: ``` (lldb) p a=10 ˄ ╰─ error: cannot assign to variable 'a' with const-qualified type 'const int &' note: note: variable 'a' declared const here ``` LLDB prints "note: " then "note: " again.

Also, "here" seems like it would be accompanied by some location but is not.

[DavidSpickett]

@adrian-prantl maybe you are aware of this but I figured I would report it anyway.

[Michael137]

Not sure where the redundant note: comes from, but the declared const here message comes from the Clang parser and we just don't attach source locations to decls in LLDB's AST, so we get this diagnostic that points to nothing (something I want to address in #127829, though got side-tracked with other things currently)

[svs-quic]

Sort of a hacky fix but the following diff seems to work:

diff --git a/lldb/source/Utility/DiagnosticsRendering.cpp b/lldb/source/Utility/DiagnosticsRendering.cpp
index 368e2199b749..e94ad0885bcd 100644
--- a/lldb/source/Utility/DiagnosticsRendering.cpp
+++ b/lldb/source/Utility/DiagnosticsRendering.cpp
@@ -220,7 +220,10 @@ void RenderDiagnosticDetails(Stream &stream,
 
   // Print the non-located details.
   for (const DiagnosticDetail &detail : other_details) {
-    PrintSeverity(stream, detail.severity);
+    if ((detail.rendered.find("note:") != std::string::npos) &&
+        (detail.rendered.find("error:") != std::string::npos) &&
+        (detail.rendered.find("warning:") != std::string::npos))
+      PrintSeverity(stream, detail.severity);
     stream << detail.rendered << '\n';
     did_print = true;
   }

[jimingham]

Sort of a hacky fix but the following diff seems to work:

diff --git a/lldb/source/Utility/DiagnosticsRendering.cpp b/lldb/source/Utility/DiagnosticsRendering.cpp
index 368e2199b749..e94ad0885bcd 100644
--- a/lldb/source/Utility/DiagnosticsRendering.cpp
+++ b/lldb/source/Utility/DiagnosticsRendering.cpp
@@ -220,7 +220,10 @@ void RenderDiagnosticDetails(Stream &stream,
 
   // Print the non-located details.
   for (const DiagnosticDetail &detail : other_details) {
-    PrintSeverity(stream, detail.severity);
+    if ((detail.rendered.find("note:") != std::string::npos) &&
+        (detail.rendered.find("error:") != std::string::npos) &&
+        (detail.rendered.find("warning:") != std::string::npos))
+      PrintSeverity(stream, detail.severity);
     stream << detail.rendered << '\n';
     did_print = true;
   }

This would be okay if you just checked for it as the beginning of the string. You wouldn't want to suppress this leading text just because somewhere in the diagnostic detail it said "warning:"...

[adrian-prantl]

I suspect that because the note is not attached to a source location we go through the old code path here. The right thing to do would be to take the non-rendered version of the diagnostic and have LLDB print the note: with the optional color.