Check pointer types for arguments of Neon load/store macros. rdar://9958031

The Neon load/store intrinsics need to be implemented as macros to avoid
hiding alignment attributes on the pointer arguments, and the macros can
only evaluate those pointer arguments once (in case they have side effects),
so it has been hard to get the right type checking for those pointers.
I tried various alternatives in the arm_neon.h header, but it's much more
straightforward to just check directly in Sema.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144075 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 54 insertions, 3 deletions

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 90b9738039..cd07358b15 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -268,11 +268,38 @@ static unsigned RFT(unsigned t, bool shift = false) {
   return 0;
 }
 
+/// getNeonEltType - Return the QualType corresponding to the elements of
+/// the vector type specified by the NeonTypeFlags.  This is used to check
+/// the pointer arguments for Neon load/store intrinsics.
+static QualType getNeonEltType(NeonTypeFlags Flags, ASTContext &Context) {
+  switch (Flags.getEltType()) {
+  case NeonTypeFlags::Int8:
+    return Flags.isUnsigned() ? Context.UnsignedCharTy : Context.SignedCharTy;
+  case NeonTypeFlags::Int16:
+    return Flags.isUnsigned() ? Context.UnsignedShortTy : Context.ShortTy;
+  case NeonTypeFlags::Int32:
+    return Flags.isUnsigned() ? Context.UnsignedIntTy : Context.IntTy;
+  case NeonTypeFlags::Int64:
+    return Flags.isUnsigned() ? Context.UnsignedLongLongTy : Context.LongLongTy;
+  case NeonTypeFlags::Poly8:
+    return Context.SignedCharTy;
+  case NeonTypeFlags::Poly16:
+    return Context.ShortTy;
+  case NeonTypeFlags::Float16:
+    return Context.UnsignedShortTy;
+  case NeonTypeFlags::Float32:
+    return Context.FloatTy;
+  }
+  return QualType();
+}
+
 bool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
   llvm::APSInt Result;
 
   unsigned mask = 0;
   unsigned TV = 0;
+  bool HasPtr = false;
+  bool HasConstPtr = false;
   switch (BuiltinID) {
 #define GET_NEON_OVERLOAD_CHECK
 #include "clang/Basic/arm_neon.inc"
@@ -281,15 +308,39 @@ bool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
   
   // For NEON intrinsics which are overloaded on vector element type, validate
   // the immediate which specifies which variant to emit.
+  unsigned ImmArg = TheCall->getNumArgs()-1;
   if (mask) {
-    unsigned ArgNo = TheCall->getNumArgs()-1;
-    if (SemaBuiltinConstantArg(TheCall, ArgNo, Result))
+    if (SemaBuiltinConstantArg(TheCall, ImmArg, Result))
       return true;
     
     TV = Result.getLimitedValue(64);
     if ((TV > 63) || (mask & (1 << TV)) == 0)
       return Diag(TheCall->getLocStart(), diag::err_invalid_neon_type_code)
-        << TheCall->getArg(ArgNo)->getSourceRange();
+        << TheCall->getArg(ImmArg)->getSourceRange();
+  }
+
+  if (HasPtr || HasConstPtr) {
+    // Check that pointer arguments have the specified type.
+    for (unsigned ArgNo = 0; ArgNo < ImmArg; ++ArgNo) {
+      Expr *Arg = TheCall->getArg(ArgNo);
+      if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg))
+        Arg = ICE->getSubExpr();
+      ExprResult RHS = DefaultFunctionArrayLvalueConversion(Arg);
+      QualType RHSTy = RHS.get()->getType();
+      if (!RHSTy->isPointerType())
+        continue;
+      QualType EltTy = getNeonEltType(NeonTypeFlags(TV), Context);
+      if (HasConstPtr)
+        EltTy = EltTy.withConst();
+      QualType LHSTy = Context.getPointerType(EltTy);
+      AssignConvertType ConvTy;
+      ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS);
+      if (RHS.isInvalid())
+        return true;
+      if (DiagnoseAssignmentResult(ConvTy, Arg->getLocStart(), LHSTy, RHSTy,
+                                   RHS.get(), AA_Assigning))
+        return true;
+    }
   }
   
   // For NEON intrinsics which take an immediate value as part of the