[clang] [Clang] Implement P2809: Trivial infinite loops are not Undefined Behavior (PR #90066)

[Eli Friedman via cfe-commits]

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@@ -908,6 +908,74 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
     incrementProfileCounter(&S);
 }
 
+bool CodeGenFunction::checkIfLoopMustProgress(const Expr *ControllingExpression,
+                                              bool IsTrivialCXXLoop) {
+  if (CGM.getCodeGenOpts().getFiniteLoops() ==
+      CodeGenOptions::FiniteLoopsKind::Never)
+    return false;
+
+  if (CGM.getCodeGenOpts().getFiniteLoops() ==
+          CodeGenOptions::FiniteLoopsKind::Always &&
+      !getLangOpts().CPlusPlus11)
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efriedma-quic wrote:

If we're going to define -ffinite-loops to allow trivial infinite loops, might as well do it in all modes, not just C++11 mode?

https://github.com/llvm/llvm-project/pull/90066