Does Project-specific compiler warning suppression affect LSP diagnostics in RAD Studio?

Question

In RAD Studio 12, developers can suppress specific compiler warnings (such as W1000) through Project > Options > Delphi Compiler > Hints and Warnings. This ensures that the Message View remains clean during build processes by filtering out known non-critical issues.

However, the Language Server Protocol (LSP) based Code Insight engine provides real-time diagnostics directly in the editor gutter. These diagnostics are governed by global settings under Tools > Options > Language > Code Insight, creating a potential discrepancy where a warning is suppressed during the build but remains visible as a gutter marker during active coding.

What is the mechanism for synchronizing project-level warning suppressions with the real-time LSP diagnostics engine? Is there a way to ensure that warnings disabled in the project options are also hidden from the editor's real-time diagnostics without disabling global Code Insight settings?

Tasadduq Burney · Answer

Direct Answer
No. Project-specific compiler warning suppressions set in Project > Options > Delphi Compiler > Hints and Warnings do not propagate to the Language Server Protocol (LSP) diagnostics engine in RAD Studio 12. The two systems operate independently.

Confirmed Behavior

Build-time suppression (project options) affects only the command-line compilers (dcc32, dcc64, dccosx64, etc.) during explicit builds. The Message View reflects these settings.
Real-time LSP diagnostics are governed exclusively by global settings at Tools > Options > Language > Code Insight > Delphi > Diagnostics. The DelphiLSP server reads its configuration from the user registry hive HKCU\Software\Embarcadero\BDS\23.0\LSP\Delphi and does not parse .dproj files for warning masks.
A warning disabled in project options (e.g., W1000) will still appear as a gutter marker, in the Structure pane, and in the LSP Diagnostics panel until the same diagnostic is disabled globally.

Why the Discrepancy Exists
The DelphiLSP server is a separate process (DelphiLSP.exe) that starts once per IDE session. It loads its diagnostic configuration at startup from the global registry key and caches it. Project files are not consulted for LSP diagnostic rules in RAD Studio 12.0–12.2.

Workarounds

Global disable (simplest): Open Tools > Options > Language > Code Insight > Delphi > Diagnostics, uncheck the specific warning (e.g., W1000), then restart the LSP server with Ctrl+Shift+Alt+L or restart the IDE. This hides the diagnostic for all projects.
Per-project illusion via global profile: Create a named Code Insight profile that matches your project's suppression list. Switch to that profile when working on the project. This is manual; the IDE does not auto-switch profiles per project.
Accept the gutter noise: Keep global diagnostics enabled and treat the gutter markers as reminders that the warning exists in other codebases.

Verification Steps

Open a project, suppress W1000 in Project Options > Delphi Compiler > Hints and Warnings.
Write code that triggers W1000 (e.g., an unused unit in uses).
Observe the gutter marker and LSP Diagnostics panel — the warning appears despite project suppression.
Go to global Code Insight Diagnostics, uncheck W1000, press Ctrl+Shift+Alt+L.
The gutter marker disappears. Re-enable globally; it returns.
Optional: Open View > LSP Log and filter for "diagnostic" entries; they reference global settings only.

One Clarifying Detail
Are you using RAD Studio 12.0, 12.1, or 12.2? If a 12.3 update has been released, project-scoped LSP settings might have been added — though no public roadmap confirmed this as of the 2026-11-13 knowledge cutoff. The workaround above applies to all 12.x versions prior to such a change.

Does Project-specific compiler warning suppression affect LSP diagnostics in RAD Studio?

1 answer

Direct Answer

Confirmed Behavior

Why the Discrepancy Exists

Workarounds

Verification Steps

One Clarifying Detail

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