[clang] [clang][SME] Ignore flatten/clang::always_inline statements for callees with mismatched streaming attributes (PR #116391)

[Benjamin Maxwell via cfe-commits]

================
@@ -1143,30 +1146,63 @@ void AArch64TargetCodeGenInfo::checkFunctionABI(
   }
 }
 
-void AArch64TargetCodeGenInfo::checkFunctionCallABIStreaming(
-    CodeGenModule &CGM, SourceLocation CallLoc, const FunctionDecl *Caller,
-    const FunctionDecl *Callee) const {
-  if (!Caller || !Callee || !Callee->hasAttr<AlwaysInlineAttr>())
-    return;
+enum class ArmSMEInlinability : uint8_t {
+  Ok = 0,
+  MismatchedStreamingCompatibility = 1 << 0,
+  IncompatibleStreamingModes = 1 << 1,
+  CalleeRequiresNewZA = 1 << 2,
+  LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/CalleeRequiresNewZA),
+};
 
+/// Determines if there are any Arm SME ABI issues with inlining \p Callee into
+/// \p Caller. Returns the issues in the ArmSMEInlinability bit enum (multiple
+/// bits can be set).
+static ArmSMEInlinability GetArmSMEInlinability(const FunctionDecl *Caller,
+                                                const FunctionDecl *Callee) {
   bool CallerIsStreaming =
       IsArmStreamingFunction(Caller, /*IncludeLocallyStreaming=*/true);
   bool CalleeIsStreaming =
       IsArmStreamingFunction(Callee, /*IncludeLocallyStreaming=*/true);
   bool CallerIsStreamingCompatible = isStreamingCompatible(Caller);
   bool CalleeIsStreamingCompatible = isStreamingCompatible(Callee);
 
+  ArmSMEInlinability Inlinability = ArmSMEInlinability::Ok;
+
   if (!CalleeIsStreamingCompatible &&
-      (CallerIsStreaming != CalleeIsStreaming || CallerIsStreamingCompatible))
-    CGM.getDiags().Report(
-        CallLoc, CalleeIsStreaming
-                     ? diag::err_function_always_inline_attribute_mismatch
-                     : diag::warn_function_always_inline_attribute_mismatch)
-        << Caller->getDeclName() << Callee->getDeclName() << "streaming";
+      (CallerIsStreaming != CalleeIsStreaming || CallerIsStreamingCompatible)) {
+    Inlinability |= ArmSMEInlinability::MismatchedStreamingCompatibility;
+    if (CalleeIsStreaming)
+      Inlinability |= ArmSMEInlinability::IncompatibleStreamingModes;
+  }
----------------
MacDue wrote:

Done :+1: 

https://github.com/llvm/llvm-project/pull/116391