union, rename, scalar types

Author: huixie90

clang/include/clang/Basic/Builtins.def

@@ -633,7 +633,7 @@ BUILTIN(__builtin_vsscanf, "icC*RcC*Ra", "FS:1:")
 BUILTIN(__builtin_thread_pointer, "v*", "nc")
 BUILTIN(__builtin_launder, "v*v*", "ntE")
 LANGBUILTIN(__builtin_is_constant_evaluated, "b", "nE", CXX_LANG)
-LANGBUILTIN(__builtin_zero_non_value_bits, "v.", "n", CXX_LANG)
+LANGBUILTIN(__builtin_clear_padding, "v.", "n", CXX_LANG)
 
 // GCC exception builtins
 BUILTIN(__builtin_eh_return, "vzv*", "r") // FIXME: Takes intptr_t, not size_t!

clang/lib/CodeGen/CGBuiltin.cpp

@@ -60,6 +60,7 @@
 #include "llvm/Support/ScopedPrinter.h"
 #include "llvm/TargetParser/AArch64TargetParser.h"
 #include "llvm/TargetParser/X86TargetParser.h"
+#include <algorithm>
 #include <optional>
 #include <sstream>
 
@@ -2468,7 +2469,12 @@ void ClearPaddingStruct(CodeGenFunction &CGF, Value *Ptr, QualType Ty, StructTyp
                         size_t CurrentStartOffset, size_t &RunningOffset, T&& WriteZeroAtOffset) {
   std::cerr << "\n struct! " << ST->getName().data() << std::endl;
   auto SL = CGF.CGM.getModule().getDataLayout().getStructLayout(ST);
-  auto R = cast<CXXRecordDecl>(Ty->getAsRecordDecl());
+
+  auto R = dyn_cast<CXXRecordDecl>(Ty->getAsRecordDecl());
+  if(!R) {
+    std::cerr << "\n not a CXXRecordDecl" << std::endl;
+
+  }
   const ASTRecordLayout &ASTLayout = CGF.getContext().getASTRecordLayout(R);
   for (auto Base : R->bases()) {
     std::cerr << "\n\n base!"  << std::endl;
@@ -2546,16 +2552,18 @@ void RecursivelyClearPaddingImpl(CodeGenFunction &CGF, Value *Ptr, QualType Ty,
   if (auto *AT = dyn_cast<ConstantArrayType>(Ty)) {
     ClearPaddingConstantArray(CGF, Ptr, Type, AT, CurrentStartOffset, RunningOffset, WriteZeroAtOffset);
   }
-  else if (auto *ST = dyn_cast<StructType>(Type)) {
+  else if (auto *ST = dyn_cast<StructType>(Type); ST && Ty->isRecordType()) {
     ClearPaddingStruct(CGF, Ptr, Ty, ST, CurrentStartOffset, RunningOffset, WriteZeroAtOffset);
+  } else if (Ty->isAtomicType()) {
+    RecursivelyClearPaddingImpl(CGF, Ptr, Ty.getAtomicUnqualifiedType(), CurrentStartOffset, RunningOffset, WriteZeroAtOffset);
   } else {
     std::cerr << "\n\n increment running offset from: " << RunningOffset << " to " << RunningOffset + Size << std::endl;
-    RunningOffset += Size;
+    RunningOffset = std::max(RunningOffset, CurrentStartOffset + static_cast<size_t>(Size));
   }
 
 }
 
-static void RecursivelyZeroNonValueBits(CodeGenFunction &CGF, Value *Ptr,
+static void RecursivelyClearPadding(CodeGenFunction &CGF, Value *Ptr,
                                         QualType Ty) {
   auto *I8Ptr = CGF.Builder.CreateBitCast(Ptr, CGF.Int8PtrTy);
   auto *Zero = ConstantInt::get(CGF.Int8Ty, 0);
@@ -2577,8 +2585,8 @@ static void RecursivelyZeroNonValueBits(CodeGenFunction &CGF, Value *Ptr,
 
   auto Size = CGF.CGM.getModule()
                     .getDataLayout()
-                    .getTypeSizeInBits(Type)
-                    .getKnownMinValue() / 8;
+                    .getTypeAllocSize(Type)
+                    .getKnownMinValue();
 
   std::cerr << "\n\n  zero tail padding  ["<< RunningOffset << ", " << Size << ")"<< std::endl;
   for (; RunningOffset < Size; ++RunningOffset) {
@@ -4445,11 +4453,11 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
 
     return RValue::get(Ptr);
   }
-  case Builtin::BI__builtin_zero_non_value_bits: {
+  case Builtin::BI__builtin_clear_padding: {
     const Expr *Op = E->getArg(0);
     Value *Address = EmitScalarExpr(Op);
     auto PointeeTy = Op->getType()->getPointeeType();
-    RecursivelyZeroNonValueBits(*this, Address, PointeeTy);
+    RecursivelyClearPadding(*this, Address, PointeeTy);
     return RValue::get(nullptr);
   }
   case Builtin::BI__sync_fetch_and_add:

clang/lib/Sema/SemaChecking.cpp

@@ -2327,24 +2327,23 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
   }
   case Builtin::BI__builtin_launder:
     return SemaBuiltinLaunder(*this, TheCall);
-  case Builtin::BI__builtin_zero_non_value_bits: {
-    // const Expr *PtrArg = TheCall->getArg(0)->IgnoreParenImpCasts();
-    // const QualType PtrArgType = PtrArg->getType();
-    // if (!PtrArgType->isPointerType() ||
-    //     !PtrArgType->getPointeeType()->isRecordType()) {
-    //   Diag(PtrArg->getBeginLoc(), diag::err_typecheck_convert_incompatible)
-    //       << PtrArgType << "structure pointer" << 1 << 0 << 3 << 1 << PtrArgType
-    //       << "structure pointer";
-    //   return ExprError();
-    // }
-    // if (PtrArgType->getPointeeType().isConstQualified()) {
-    //   Diag(PtrArg->getBeginLoc(), diag::err_typecheck_assign_const)
-    //       << TheCall->getSourceRange() << 5 /*ConstUnknown*/;
-    //   return ExprError();
-    // }
-    // if (RequireCompleteType(PtrArg->getBeginLoc(), PtrArgType->getPointeeType(),
-    //                         diag::err_typecheck_decl_incomplete_type))
-    //   return ExprError();
+  case Builtin::BI__builtin_clear_padding: {
+    const Expr *PtrArg = TheCall->getArg(0)->IgnoreParenImpCasts();
+    const QualType PtrArgType = PtrArg->getType();
+    if (!PtrArgType->isPointerType()) {
+      Diag(PtrArg->getBeginLoc(), diag::err_typecheck_convert_incompatible)
+          << PtrArgType << "pointer" << 1 << 0 << 3 << 1 << PtrArgType
+          << "pointer";
+      return ExprError();
+    }
+    if (PtrArgType->getPointeeType().isConstQualified()) {
+      Diag(PtrArg->getBeginLoc(), diag::err_typecheck_assign_const)
+          << TheCall->getSourceRange() << 5 /*ConstUnknown*/;
+      return ExprError();
+    }
+    if (RequireCompleteType(PtrArg->getBeginLoc(), PtrArgType->getPointeeType(),
+                            diag::err_typecheck_decl_incomplete_type))
+      return ExprError();
     break;
   }
   case Builtin::BI__sync_fetch_and_add:

clang/test/CodeGenCXX/builtin-zero-non-value-bits-codegen.cpp renamed to clang/test/CodeGenCXX/builtin-clear-padding-codegen.cpp

@@ -49,7 +49,7 @@ struct alignas(4) Baz : Foo {
 // CHECK: store i8 0, i8* [[PAD_7]]
 // CHECK: ret void
 void testBaz(Baz *baz) {
-  __builtin_zero_non_value_bits(baz);
+  __builtin_clear_padding(baz);
 }
 
 struct UnsizedTail {
@@ -78,7 +78,7 @@ struct UnsizedTail {
 // CHECK: store i8 0, i8* [[PAD_4]]
 // CHECK: ret void
 void testUnsizedTail(UnsizedTail *u) {
-  __builtin_zero_non_value_bits(u);
+  __builtin_clear_padding(u);
 }
 
 struct ArrOfStructsWithPadding {
@@ -108,5 +108,5 @@ struct ArrOfStructsWithPadding {
 // CHECK: store i8 0, i8* [[PAD_4]]
 // CHECK: ret void
 void testArrOfStructsWithPadding(ArrOfStructsWithPadding *arr) {
-  __builtin_zero_non_value_bits(arr);
+  __builtin_clear_padding(arr);
 }