[RISCV][clang] Support RISC-V vectors in UninitializedValues.

[craig.topper]

Summary

RISC-V vectors are basically vectors, but we use builtin types to
restrict the possible types. Treat them the same as vectors and scalars
for this analysis.

[reames]

LGTM

clang/include/clang/AST/Type.h

 //===- Type.h - C Language Family Type Representation -----------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
#include "clang/Basic/OpenCLExtensionTypes.def"
   /// than implicitly __strong.
   bool isObjCARCImplicitlyUnretainedType() const;
 
   /// Check if the type is the CUDA device builtin surface type.
   bool isCUDADeviceBuiltinSurfaceType() const;
   /// Check if the type is the CUDA device builtin texture type.
   bool isCUDADeviceBuiltinTextureType() const;
 
+  bool isRVVType() const;
+
   /// Return the implicit lifetime for this type, which must not be dependent.
   Qualifiers::ObjCLifetime getObjCARCImplicitLifetime() const;
 
   enum ScalarTypeKind {
     STK_CPointer,
     STK_BlockPointer,
     STK_ObjCObjectPointer,
     STK_MemberPointer,
#include "clang/Basic/OpenCLExtensionTypes.def"
     false; // end of boolean or operation
 }
 
 inline bool Type::isOpenCLSpecificType() const {
   return isSamplerT() || isEventT() || isImageType() || isClkEventT() ||
          isQueueT() || isReserveIDT() || isPipeType() || isOCLExtOpaqueType();
 }
 
+inline bool Type::isRVVType() const {
+#define RVV_TYPE(Name, Id, SingletonId) \
+  isSpecificBuiltinType(BuiltinType::Id) ||
+  return
+#include "clang/Basic/RISCVVTypes.def"
+    false; // end of boolean or operation.
+}
+
 inline bool Type::isTemplateTypeParmType() const {
   return isa<TemplateTypeParmType>(CanonicalType);
 }
 
 inline bool Type::isSpecificBuiltinType(unsigned K) const {
   if (const BuiltinType *BT = getAs<BuiltinType>()) {
     return BT->getKind() == static_cast<BuiltinType::Kind>(K);
   }

clang/lib/Analysis/UninitializedValues.cpp

 //===- UninitializedValues.cpp - Find Uninitialized Values ----------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //

 
 #define DEBUG_LOGGING 0
 
 static bool isTrackedVar(const VarDecl *vd, const DeclContext *dc) {
   if (vd->isLocalVarDecl() && !vd->hasGlobalStorage() &&
       !vd->isExceptionVariable() && !vd->isInitCapture() &&
       !vd->isImplicit() && vd->getDeclContext() == dc) {
     QualType ty = vd->getType();
-    return ty->isScalarType() || ty->isVectorType() || ty->isRecordType();
+    return ty->isScalarType() || ty->isVectorType() || ty->isRecordType() ||
+           ty->isRVVType();
   }
   return false;
 }
 
 //------------------------------------------------------------------------====//
 // DeclToIndex: a mapping from Decls we track to value indices.
 //====------------------------------------------------------------------------//
 

clang/test/Sema/uninit-variables-riscv-vector.c

+// RUN: %clang_cc1 -triple riscv64 -fsyntax-only -Wuninitialized -fsyntax-only -target-feature +v %s -verify
+
+#pragma clang riscv intrinsic vector
+
+void test1(int *input, long vl) {
+  __rvv_int32m1_t x, y, z, w, X; // expected-note {{variable 'x' is declared here}} expected-note {{variable 'y' is declared here}} expected-note {{variable 'w' is declared here}}  expected-note {{variable 'z' is declared here}}
+  x = vxor_vv_i32m1(x,x, vl); // expected-warning {{variable 'x' is uninitialized when used here}}
+  y = vxor_vv_i32m1(y,y, vl); // expected-warning {{variable 'y' is uninitialized when used here}}
+  z = vxor_vv_i32m1(z,z, vl); // expected-warning {{variable 'z' is uninitialized when used here}}
+  w = vxor_vv_i32m1(w,w, vl); // expected-warning {{variable 'w' is uninitialized when used here}}
+  X = vle32_v_i32m1(&input[0], vl);
+  X = vxor_vv_i32m1(X,X, vl); // no-warning
+}
+