[clang] [HLSL] Strict Availability Diagnostics (PR #93860)

[Helena Kotas via cfe-commits]

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@@ -834,34 +829,55 @@ void DiagnoseUnguardedAvailability::DiagnoseDeclAvailability(
                                              OffendingDecl))
       return;
 
-    // We would like to emit the diagnostic even if -Wunguarded-availability is
-    // not specified for deployment targets >= to iOS 11 or equivalent or
-    // for declarations that were introduced in iOS 11 (macOS 10.13, ...) or
-    // later.
-    bool UseNewDiagKind = shouldDiagnoseAvailabilityByDefault(
-        SemaRef.Context,
-        SemaRef.Context.getTargetInfo().getPlatformMinVersion(), Introduced);
-
     const TargetInfo &TI = SemaRef.getASTContext().getTargetInfo();
+
+    // In HLSL, emit diagnostic here during parsing only if the diagnostic
+    // mode is set to strict (-fhlsl-strict-availability), and either the decl
+    // availability is not restricted to a specific environment/shader stage,
+    // or the target stage is known (= it is not shader library).
+    const LangOptions &LandOpts = SemaRef.getLangOpts();
+    if (LandOpts.HLSL) {
+      if (!LandOpts.HLSLStrictAvailability ||
+          (AA->getEnvironment() != nullptr &&
+           TI.getTriple().getEnvironment() ==
+               llvm::Triple::EnvironmentType::Library))
+        return;
+    }
----------------
hekota wrote:

`shouldDiagnoseAvailabilityByDefault` just determines which diag id to use, not wherther to skip the diagnostic. But I can move it to `ShouldDiagnoseAvailabilityInContext`.

https://github.com/llvm/llvm-project/pull/93860