[clang] [llvm] [Clang][SME] Detect always_inline used with mismatched streaming attributes (PR #77936)

[Sam Tebbs via cfe-commits]

================
@@ -814,6 +820,49 @@ Address AArch64ABIInfo::EmitMSVAArg(CodeGenFunction &CGF, Address VAListAddr,
                           /*allowHigherAlign*/ false);
 }
 
+class SMEAttributes {
+public:
+  bool IsStreaming = false;
+  bool IsStreamingCompatible = false;
+  bool HasNewZA = false;
+
+  SMEAttributes(const FunctionDecl *F) {
+    if (F->hasAttr<ArmLocallyStreamingAttr>())
+      IsStreaming = true;
+    if (auto *NewAttr = F->getAttr<ArmNewAttr>()) {
+      if (NewAttr->isNewZA())
+        HasNewZA = true;
+    }
+    if (const auto *T = F->getType()->getAs<FunctionProtoType>()) {
+      if (T->getAArch64SMEAttributes() & FunctionType::SME_PStateSMEnabledMask)
+        IsStreaming = true;
+      if (T->getAArch64SMEAttributes() &
+          FunctionType::SME_PStateSMCompatibleMask)
+        IsStreamingCompatible = true;
+    }
+  }
+};
+
+void AArch64TargetCodeGenInfo::checkFunctionCallABI(
+    CodeGenModule &CGM, SourceLocation CallLoc, const FunctionDecl *Caller,
+    const FunctionDecl *Callee, const CallArgList &Args) const {
+  if (!Callee->hasAttr<AlwaysInlineAttr>())
+    return;
+
+  SMEAttributes CalleeAttrs(Callee);
+  SMEAttributes CallerAttrs(Caller);
----------------
SamTebbs33 wrote:

`Caller` could actually be null here but based on where this function is called in `CGCall`, `Callee` can't. I've added a null check on `Caller`. Thanks!

https://github.com/llvm/llvm-project/pull/77936