[clang] [clang][Sema] Optimize ~SemaDiagnosticBuilder (PR #142252)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>

Call getDiagnosticLevel(), which is expensive, only if ShowCallStack is set.

Small gains:
https://llvm-compile-time-tracker.com/compare.php?from=843e362318e884991e517a54446b4faeacdad789&to=5cef0c18466318a426924b3c45f7abaaa8f6b535&stat=instructions:u

---
Full diff: https://github.com/llvm/llvm-project/pull/142252.diff


1 Files Affected:

- (modified) clang/lib/Sema/Sema.cpp (+7-4) 


``````````diff
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 1901d19b14dfc..ff4c0d833e573 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -2062,11 +2062,14 @@ Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() {
   if (ImmediateDiag) {
     // Emit our diagnostic and, if it was a warning or error, output a callstack
     // if Fn isn't a priori known-emitted.
-    bool IsWarningOrError = S.getDiagnostics().getDiagnosticLevel(
-                                DiagID, Loc) >= DiagnosticsEngine::Warning;
     ImmediateDiag.reset(); // Emit the immediate diag.
-    if (IsWarningOrError && ShowCallStack)
-      emitCallStackNotes(S, Fn);
+
+    if (ShowCallStack) {
+      bool IsWarningOrError = S.getDiagnostics().getDiagnosticLevel(
+                                  DiagID, Loc) >= DiagnosticsEngine::Warning;
+      if (IsWarningOrError)
+        emitCallStackNotes(S, Fn);
+    }
   } else {
     assert((!PartialDiagId || ShowCallStack) &&
            "Must always show call stack for deferred diags.");

``````````

</details>


https://github.com/llvm/llvm-project/pull/142252