test/Analysis/cast-value-notes.cpp - llvm-project/clang - Git at Google

 // RUN: %clang_analyze_cc1 -std=c++14 -triple amdgcn-unknown-unknown \
 // RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
 // RUN: -analyzer-output=text -verify -DX86 -DSUPPRESSED %s 2>&1 | FileCheck %s -check-prefix=X86-CHECK
 //
 // RUN: %clang_analyze_cc1 -std=c++14 -triple amdgcn-unknown-unknown \
 // RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
 // RUN:  -analyzer-config core.NullDereference:SuppressAddressSpaces=false\
 // RUN:  -analyzer-output=text -verify -DX86 -DNOT_SUPPRESSED %s 2>&1 | FileCheck %s -check-prefix=X86-CHECK
 //
 // RUN: %clang_analyze_cc1 -std=c++14 -triple amdgcn-unknown-unknown \
 // RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
 // RUN:  -analyzer-config core.NullDereference:SuppressAddressSpaces=true\
 // RUN:  -analyzer-output=text -verify -DX86 -DSUPPRESSED %s 2>&1 | FileCheck %s -check-prefix=X86-CHECK
 //
 // RUN: %clang_analyze_cc1 -std=c++14 -triple x86_64-unknown-unknown \
 // RUN:  -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
 // RUN:  -analyzer-output=text -verify -DX86 -DSUPPRESSED %s 2>&1 | FileCheck %s --check-prefix=X86-CHECK
 //
 // RUN: %clang_analyze_cc1 -std=c++14 -triple x86_64-unknown-unknown \
 // RUN:  -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
 // RUN:  -analyzer-config core.NullDereference:SuppressAddressSpaces=true\
 // RUN:  -analyzer-output=text -verify -DX86 -DSUPPRESSED %s 2>&1 | FileCheck %s --check-prefix=X86-CHECK-SUPPRESSED
 //
 // RUN: %clang_analyze_cc1 -std=c++14 -triple x86_64-unknown-unknown \
 // RUN:  -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
 // RUN:  -analyzer-config core.NullDereference:SuppressAddressSpaces=false\
 // RUN:  -analyzer-output=text -verify -DX86 -DNOT_SUPPRESSED %s 2>&1 | FileCheck %s --check-prefix=X86-CHECK
 //
 // RUN: %clang_analyze_cc1 -std=c++14 -triple mips-unknown-unknown \
 // RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
 // RUN: -analyzer-output=text -verify -DMIPS %s 2>&1
 //
 // RUN: %clang_analyze_cc1 -std=c++14 -triple mips-unknown-unknown \
 // RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
 // RUN: -analyzer-config core.NullDereference:SuppressAddressSpaces=false\
 // RUN: -analyzer-output=text -verify -DMIPS %s 2>&1
 //
 // RUN: %clang_analyze_cc1 -std=c++14 -triple mips-unknown-unknown \
 // RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
 // RUN: -analyzer-config core.NullDereference:SuppressAddressSpaces=true\
 // RUN: -analyzer-output=text -verify -DMIPS_SUPPRESSED %s

 #include "Inputs/llvm.h"

 // The amggcn triple case uses an intentionally different address space.
 // The core.NullDereference checker intentionally ignores checks
 // that use address spaces, so the case is differentiated here.
 //
 // From https://llvm.org/docs/AMDGPUUsage.html#address-spaces,
 // select address space 3 (local), since the pointer size is
 // different than Generic.
 #define DEVICE __attribute__((address_space(3)))

 namespace clang {
 struct Shape {
   template <typename T>
   const T *castAs() const;

   template <typename T>
   const T *getAs() const;
 };
 class Triangle : public Shape {};
 class Rectangle : public Shape {};
 class Hexagon : public Shape {};
 class Circle : public Shape {};
 } // namespace clang

 using namespace llvm;
 using namespace clang;

 void clang_analyzer_printState();

 #if defined(X86)
 void evalReferences(const Shape &S) {
   const auto &C = dyn_cast<Circle>(S);
   // expected-note@-1 {{Assuming 'S' is not a 'const class clang::Circle &'}}
   // expected-note@-2 {{Dereference of null pointer}}
   // expected-warning@-3 {{Dereference of null pointer}}
   clang_analyzer_printState();
   // XX86-CHECK:      "dynamic_types": [
   // XX86-CHECK-NEXT:   { "region": "SymRegion{reg_$0<const struct clang::Shape & S>}", "dyn_type": "const class clang::Circle &", "sub_classable": true }
   (void)C;
 }
 #if defined(SUPPRESSED)
 void evalReferences_addrspace(const Shape &S) {
   const auto &C = dyn_cast<DEVICE Circle>(S);
   clang_analyzer_printState();
   // X86-CHECK-SUPPRESSED: "dynamic_types": [
   // X86-CHECK-SUPPRESSED-NEXT: { "region": "SymRegion{reg_$0<const Shape & S>}", "dyn_type": "const __attribute__((address_space(3))) class clang::Circle &", "sub_classable": true }
   (void)C;
 }
 #endif
 #if defined(NOT_SUPPRESSED)
 void evalReferences_addrspace(const Shape &S) {
   const auto &C = dyn_cast<DEVICE Circle>(S);
   // expected-note@-1 {{Assuming 'S' is not a 'const __attribute__((address_space(3))) class clang::Circle &'}}
   // expected-note@-2 {{Dereference of null pointer}}
   // expected-warning@-3 {{Dereference of null pointer}}
   clang_analyzer_printState();
   // X86-CHECK: "dynamic_types": [
   // X86-CHECK-NEXT: { "region": "SymRegion{reg_$0<const Shape & S>}", "dyn_type": "const __attribute__((address_space(3))) class clang::Circle &", "sub_classable": true }
   (void)C;
 }
 #endif
 #elif defined(MIPS)
 void evalReferences(const Shape &S) {
   const auto &C = dyn_cast<Circle>(S);
   // expected-note@-1 {{Assuming 'S' is not a 'const class clang::Circle &'}}
   // expected-note@-2 {{Dereference of null pointer}}
   // expected-warning@-3 {{Dereference of null pointer}}
 }
 #if defined(MIPS_SUPPRESSED)
 void evalReferences_addrspace(const Shape &S) {
   const auto &C = dyn_cast<DEVICE Circle>(S);
   (void)C;
 }
 #endif
 #endif

 void evalNonNullParamNonNullReturnReference(const Shape &S) {
   const auto *C = dyn_cast_or_null<Circle>(S);
   // expected-note@-1 {{'C' initialized here}}

   if (!dyn_cast_or_null<Circle>(C)) {
     // expected-note@-1 {{Assuming 'C' is a 'const class clang::Circle *'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (dyn_cast_or_null<Triangle>(C)) {
     // expected-note@-1 {{Assuming 'C' is not a 'const class clang::Triangle *'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (dyn_cast_or_null<Rectangle>(C)) {
     // expected-note@-1 {{Assuming 'C' is not a 'const class clang::Rectangle *'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (dyn_cast_or_null<Hexagon>(C)) {
     // expected-note@-1 {{Assuming 'C' is not a 'const class clang::Hexagon *'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (isa<Triangle>(C)) {
     // expected-note@-1 {{'C' is not a 'Triangle'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (isa<Triangle, Rectangle>(C)) {
     // expected-note@-1 {{'C' is neither a 'Triangle' nor a 'Rectangle'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (isa<Triangle, Rectangle, Hexagon>(C)) {
     // expected-note@-1 {{'C' is neither a 'Triangle' nor a 'Rectangle' nor a 'Hexagon'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (isa<Circle, Rectangle, Hexagon>(C)) {
     // expected-note@-1 {{'C' is a 'Circle'}}
     // expected-note@-2 {{Taking true branch}}

     (void)(1 / !C);
     // expected-note@-1 {{'C' is non-null}}
     // expected-note@-2 {{Division by zero}}
     // expected-warning@-3 {{Division by zero}}
   }
 }

 void evalNonNullParamNonNullReturn(const Shape *S) {
   const auto *C = cast<Circle>(S);
   // expected-note@-1 {{'S' is a 'const class clang::Circle *'}}
   // expected-note@-2 {{'C' initialized here}}

   if (!dyn_cast_or_null<Circle>(C)) {
     // expected-note@-1 {{Assuming 'C' is a 'const class clang::Circle *'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (dyn_cast_or_null<Triangle>(C)) {
     // expected-note@-1 {{Assuming 'C' is not a 'const class clang::Triangle *'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (dyn_cast_or_null<Rectangle>(C)) {
     // expected-note@-1 {{Assuming 'C' is not a 'const class clang::Rectangle *'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (dyn_cast_or_null<Hexagon>(C)) {
     // expected-note@-1 {{Assuming 'C' is not a 'const class clang::Hexagon *'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (isa<Triangle>(C)) {
     // expected-note@-1 {{'C' is not a 'Triangle'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (isa<Triangle, Rectangle>(C)) {
     // expected-note@-1 {{'C' is neither a 'Triangle' nor a 'Rectangle'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (isa<Triangle, Rectangle, Hexagon>(C)) {
     // expected-note@-1 {{'C' is neither a 'Triangle' nor a 'Rectangle' nor a 'Hexagon'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (isa<Circle, Rectangle, Hexagon>(C)) {
     // expected-note@-1 {{'C' is a 'Circle'}}
     // expected-note@-2 {{Taking true branch}}

     (void)(1 / !C);
     // expected-note@-1 {{'C' is non-null}}
     // expected-note@-2 {{Division by zero}}
     // expected-warning@-3 {{Division by zero}}
   }
 }

 void evalNonNullParamNullReturn(const Shape *S) {
   const auto *C = dyn_cast_or_null<Circle>(S);
   // expected-note@-1 {{Assuming 'S' is not a 'const class clang::Circle *'}}

   if (const auto *T = dyn_cast_or_null<Triangle>(S)) {
     // expected-note@-1 {{Assuming 'S' is a 'const class clang::Triangle *'}}
     // expected-note@-2 {{'T' initialized here}}
     // expected-note@-3 {{'T' is non-null}}
     // expected-note@-4 {{Taking true branch}}

     (void)(1 / !T);
     // expected-note@-1 {{'T' is non-null}}
     // expected-note@-2 {{Division by zero}}
     // expected-warning@-3 {{Division by zero}}
   }
 }

 void evalNullParamNullReturn(const Shape *S) {
   const auto *C = dyn_cast_or_null<Circle>(S);
   // expected-note@-1 {{Assuming null pointer is passed into cast}}
   // expected-note@-2 {{'C' initialized to a null pointer value}}

   (void)(1 / (bool)C);
   // expected-note@-1 {{Division by zero}}
   // expected-warning@-2 {{Division by zero}}
 }

 void evalZeroParamNonNullReturnPointer(const Shape *S) {
   const auto *C = S->castAs<Circle>();
   // expected-note@-1 {{'S' is a 'const class clang::Circle *'}}
   // expected-note@-2 {{'C' initialized here}}

   (void)(1 / !C);
   // expected-note@-1 {{'C' is non-null}}
   // expected-note@-2 {{Division by zero}}
   // expected-warning@-3 {{Division by zero}}
 }

 void evalZeroParamNonNullReturn(const Shape &S) {
   const auto *C = S.castAs<Circle>();
   // expected-note@-1 {{'C' initialized here}}

   (void)(1 / !C);
   // expected-note@-1 {{'C' is non-null}}
   // expected-note@-2 {{Division by zero}}
   // expected-warning@-3 {{Division by zero}}
 }

 void evalZeroParamNullReturn(const Shape *S) {
   const auto &C = S->getAs<Circle>();
   // expected-note@-1 {{Assuming 'S' is not a 'const class clang::Circle *'}}
   // expected-note@-2 {{Storing null pointer value}}
   // expected-note@-3 {{'C' initialized here}}

   if (!dyn_cast_or_null<Triangle>(S)) {
     // expected-note@-1 {{Assuming 'S' is a 'const class clang::Triangle *'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   if (!dyn_cast_or_null<Triangle>(S)) {
     // expected-note@-1 {{'S' is a 'Triangle'}}
     // expected-note@-2 {{Taking false branch}}
     return;
   }

   (void)(1 / (bool)C);
   // expected-note@-1 {{Division by zero}}
   // expected-warning@-2 {{Division by zero}}
 }

 // don't crash
 // CastValueChecker was using QualType()->getPointeeCXXRecordDecl(), in
 // getNoteTag which evaluated to nullptr, then crashed when attempting to
 // deref an invocation to getNameAsString(). The fix is to use
 // QualType().getAsString().
 //
 // Example:
 // std::string CastToName =
 //       CastInfo ? CastInfo->to()->getAsCXXRecordDecl()->getNameAsString()
 //                : CastToTy->getPointeeCXXRecordDecl()->getNameAsString();
 // Changed to:
 // std::string CastToName =
 //       CastInfo ? CastInfo->to()->getAsCXXRecordDecl()->getNameAsString()
 //                : CastToTy.getAsString();
 namespace llvm {
 template <typename, typename a> void isa(a &);
 template <typename> class PointerUnion {
 public:
   template <typename T> T *getAs() {
     (void)isa<int>(*this);
     return nullptr;
   }
 };
 class LLVMContext {
   PointerUnion<LLVMContext> c;
   void d() { c.getAs<int>(); }
 };
 } // namespace llvm
	// RUN: %clang_analyze_cc1 -std=c++14 -triple amdgcn-unknown-unknown \
	// RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
	// RUN: -analyzer-output=text -verify -DX86 -DSUPPRESSED %s 2>&1 \| FileCheck %s -check-prefix=X86-CHECK
	//
	// RUN: %clang_analyze_cc1 -std=c++14 -triple amdgcn-unknown-unknown \
	// RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
	// RUN: -analyzer-config core.NullDereference:SuppressAddressSpaces=false\
	// RUN: -analyzer-output=text -verify -DX86 -DNOT_SUPPRESSED %s 2>&1 \| FileCheck %s -check-prefix=X86-CHECK
	//
	// RUN: %clang_analyze_cc1 -std=c++14 -triple amdgcn-unknown-unknown \
	// RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
	// RUN: -analyzer-config core.NullDereference:SuppressAddressSpaces=true\
	// RUN: -analyzer-output=text -verify -DX86 -DSUPPRESSED %s 2>&1 \| FileCheck %s -check-prefix=X86-CHECK
	//
	// RUN: %clang_analyze_cc1 -std=c++14 -triple x86_64-unknown-unknown \
	// RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
	// RUN: -analyzer-output=text -verify -DX86 -DSUPPRESSED %s 2>&1 \| FileCheck %s --check-prefix=X86-CHECK
	//
	// RUN: %clang_analyze_cc1 -std=c++14 -triple x86_64-unknown-unknown \
	// RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
	// RUN: -analyzer-config core.NullDereference:SuppressAddressSpaces=true\
	// RUN: -analyzer-output=text -verify -DX86 -DSUPPRESSED %s 2>&1 \| FileCheck %s --check-prefix=X86-CHECK-SUPPRESSED
	//
	// RUN: %clang_analyze_cc1 -std=c++14 -triple x86_64-unknown-unknown \
	// RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
	// RUN: -analyzer-config core.NullDereference:SuppressAddressSpaces=false\
	// RUN: -analyzer-output=text -verify -DX86 -DNOT_SUPPRESSED %s 2>&1 \| FileCheck %s --check-prefix=X86-CHECK
	//
	// RUN: %clang_analyze_cc1 -std=c++14 -triple mips-unknown-unknown \
	// RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
	// RUN: -analyzer-output=text -verify -DMIPS %s 2>&1
	//
	// RUN: %clang_analyze_cc1 -std=c++14 -triple mips-unknown-unknown \
	// RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
	// RUN: -analyzer-config core.NullDereference:SuppressAddressSpaces=false\
	// RUN: -analyzer-output=text -verify -DMIPS %s 2>&1
	//
	// RUN: %clang_analyze_cc1 -std=c++14 -triple mips-unknown-unknown \
	// RUN: -analyzer-checker=core,apiModeling.llvm.CastValue,debug.ExprInspection\
	// RUN: -analyzer-config core.NullDereference:SuppressAddressSpaces=true\
	// RUN: -analyzer-output=text -verify -DMIPS_SUPPRESSED %s

	#include "Inputs/llvm.h"

	// The amggcn triple case uses an intentionally different address space.
	// The core.NullDereference checker intentionally ignores checks
	// that use address spaces, so the case is differentiated here.
	//
	// From https://llvm.org/docs/AMDGPUUsage.html#address-spaces,
	// select address space 3 (local), since the pointer size is
	// different than Generic.
	#define DEVICE __attribute__((address_space(3)))

	namespace clang {
	struct Shape {
	template <typename T>
	const T *castAs() const;

	template <typename T>
	const T *getAs() const;
	};
	class Triangle : public Shape {};
	class Rectangle : public Shape {};
	class Hexagon : public Shape {};
	class Circle : public Shape {};
	} // namespace clang

	using namespace llvm;
	using namespace clang;

	void clang_analyzer_printState();

	#if defined(X86)
	void evalReferences(const Shape &S) {
	const auto &C = dyn_cast<Circle>(S);
	// expected-note@-1 {{Assuming 'S' is not a 'const class clang::Circle &'}}
	// expected-note@-2 {{Dereference of null pointer}}
	// expected-warning@-3 {{Dereference of null pointer}}
	clang_analyzer_printState();
	// XX86-CHECK: "dynamic_types": [
	// XX86-CHECK-NEXT: { "region": "SymRegion{reg_$0<const struct clang::Shape & S>}", "dyn_type": "const class clang::Circle &", "sub_classable": true }
	(void)C;
	}
	#if defined(SUPPRESSED)
	void evalReferences_addrspace(const Shape &S) {
	const auto &C = dyn_cast<DEVICE Circle>(S);
	clang_analyzer_printState();
	// X86-CHECK-SUPPRESSED: "dynamic_types": [
	// X86-CHECK-SUPPRESSED-NEXT: { "region": "SymRegion{reg_$0<const Shape & S>}", "dyn_type": "const __attribute__((address_space(3))) class clang::Circle &", "sub_classable": true }
	(void)C;
	}
	#endif
	#if defined(NOT_SUPPRESSED)
	void evalReferences_addrspace(const Shape &S) {
	const auto &C = dyn_cast<DEVICE Circle>(S);
	// expected-note@-1 {{Assuming 'S' is not a 'const __attribute__((address_space(3))) class clang::Circle &'}}
	// expected-note@-2 {{Dereference of null pointer}}
	// expected-warning@-3 {{Dereference of null pointer}}
	clang_analyzer_printState();
	// X86-CHECK: "dynamic_types": [
	// X86-CHECK-NEXT: { "region": "SymRegion{reg_$0<const Shape & S>}", "dyn_type": "const __attribute__((address_space(3))) class clang::Circle &", "sub_classable": true }
	(void)C;
	}
	#endif
	#elif defined(MIPS)
	void evalReferences(const Shape &S) {
	const auto &C = dyn_cast<Circle>(S);
	// expected-note@-1 {{Assuming 'S' is not a 'const class clang::Circle &'}}
	// expected-note@-2 {{Dereference of null pointer}}
	// expected-warning@-3 {{Dereference of null pointer}}
	}
	#if defined(MIPS_SUPPRESSED)
	void evalReferences_addrspace(const Shape &S) {
	const auto &C = dyn_cast<DEVICE Circle>(S);
	(void)C;
	}
	#endif
	#endif

	void evalNonNullParamNonNullReturnReference(const Shape &S) {
	const auto *C = dyn_cast_or_null<Circle>(S);
	// expected-note@-1 {{'C' initialized here}}

	if (!dyn_cast_or_null<Circle>(C)) {
	// expected-note@-1 {{Assuming 'C' is a 'const class clang::Circle *'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (dyn_cast_or_null<Triangle>(C)) {
	// expected-note@-1 {{Assuming 'C' is not a 'const class clang::Triangle *'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (dyn_cast_or_null<Rectangle>(C)) {
	// expected-note@-1 {{Assuming 'C' is not a 'const class clang::Rectangle *'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (dyn_cast_or_null<Hexagon>(C)) {
	// expected-note@-1 {{Assuming 'C' is not a 'const class clang::Hexagon *'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (isa<Triangle>(C)) {
	// expected-note@-1 {{'C' is not a 'Triangle'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (isa<Triangle, Rectangle>(C)) {
	// expected-note@-1 {{'C' is neither a 'Triangle' nor a 'Rectangle'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (isa<Triangle, Rectangle, Hexagon>(C)) {
	// expected-note@-1 {{'C' is neither a 'Triangle' nor a 'Rectangle' nor a 'Hexagon'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (isa<Circle, Rectangle, Hexagon>(C)) {
	// expected-note@-1 {{'C' is a 'Circle'}}
	// expected-note@-2 {{Taking true branch}}

	(void)(1 / !C);
	// expected-note@-1 {{'C' is non-null}}
	// expected-note@-2 {{Division by zero}}
	// expected-warning@-3 {{Division by zero}}
	}
	}

	void evalNonNullParamNonNullReturn(const Shape *S) {
	const auto *C = cast<Circle>(S);
	// expected-note@-1 {{'S' is a 'const class clang::Circle *'}}
	// expected-note@-2 {{'C' initialized here}}

	if (!dyn_cast_or_null<Circle>(C)) {
	// expected-note@-1 {{Assuming 'C' is a 'const class clang::Circle *'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (dyn_cast_or_null<Triangle>(C)) {
	// expected-note@-1 {{Assuming 'C' is not a 'const class clang::Triangle *'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (dyn_cast_or_null<Rectangle>(C)) {
	// expected-note@-1 {{Assuming 'C' is not a 'const class clang::Rectangle *'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (dyn_cast_or_null<Hexagon>(C)) {
	// expected-note@-1 {{Assuming 'C' is not a 'const class clang::Hexagon *'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (isa<Triangle>(C)) {
	// expected-note@-1 {{'C' is not a 'Triangle'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (isa<Triangle, Rectangle>(C)) {
	// expected-note@-1 {{'C' is neither a 'Triangle' nor a 'Rectangle'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (isa<Triangle, Rectangle, Hexagon>(C)) {
	// expected-note@-1 {{'C' is neither a 'Triangle' nor a 'Rectangle' nor a 'Hexagon'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (isa<Circle, Rectangle, Hexagon>(C)) {
	// expected-note@-1 {{'C' is a 'Circle'}}
	// expected-note@-2 {{Taking true branch}}

	(void)(1 / !C);
	// expected-note@-1 {{'C' is non-null}}
	// expected-note@-2 {{Division by zero}}
	// expected-warning@-3 {{Division by zero}}
	}
	}

	void evalNonNullParamNullReturn(const Shape *S) {
	const auto *C = dyn_cast_or_null<Circle>(S);
	// expected-note@-1 {{Assuming 'S' is not a 'const class clang::Circle *'}}

	if (const auto *T = dyn_cast_or_null<Triangle>(S)) {
	// expected-note@-1 {{Assuming 'S' is a 'const class clang::Triangle *'}}
	// expected-note@-2 {{'T' initialized here}}
	// expected-note@-3 {{'T' is non-null}}
	// expected-note@-4 {{Taking true branch}}

	(void)(1 / !T);
	// expected-note@-1 {{'T' is non-null}}
	// expected-note@-2 {{Division by zero}}
	// expected-warning@-3 {{Division by zero}}
	}
	}

	void evalNullParamNullReturn(const Shape *S) {
	const auto *C = dyn_cast_or_null<Circle>(S);
	// expected-note@-1 {{Assuming null pointer is passed into cast}}
	// expected-note@-2 {{'C' initialized to a null pointer value}}

	(void)(1 / (bool)C);
	// expected-note@-1 {{Division by zero}}
	// expected-warning@-2 {{Division by zero}}
	}

	void evalZeroParamNonNullReturnPointer(const Shape *S) {
	const auto *C = S->castAs<Circle>();
	// expected-note@-1 {{'S' is a 'const class clang::Circle *'}}
	// expected-note@-2 {{'C' initialized here}}

	(void)(1 / !C);
	// expected-note@-1 {{'C' is non-null}}
	// expected-note@-2 {{Division by zero}}
	// expected-warning@-3 {{Division by zero}}
	}

	void evalZeroParamNonNullReturn(const Shape &S) {
	const auto *C = S.castAs<Circle>();
	// expected-note@-1 {{'C' initialized here}}

	(void)(1 / !C);
	// expected-note@-1 {{'C' is non-null}}
	// expected-note@-2 {{Division by zero}}
	// expected-warning@-3 {{Division by zero}}
	}

	void evalZeroParamNullReturn(const Shape *S) {
	const auto &C = S->getAs<Circle>();
	// expected-note@-1 {{Assuming 'S' is not a 'const class clang::Circle *'}}
	// expected-note@-2 {{Storing null pointer value}}
	// expected-note@-3 {{'C' initialized here}}

	if (!dyn_cast_or_null<Triangle>(S)) {
	// expected-note@-1 {{Assuming 'S' is a 'const class clang::Triangle *'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	if (!dyn_cast_or_null<Triangle>(S)) {
	// expected-note@-1 {{'S' is a 'Triangle'}}
	// expected-note@-2 {{Taking false branch}}
	return;
	}

	(void)(1 / (bool)C);
	// expected-note@-1 {{Division by zero}}
	// expected-warning@-2 {{Division by zero}}
	}

	// don't crash
	// CastValueChecker was using QualType()->getPointeeCXXRecordDecl(), in
	// getNoteTag which evaluated to nullptr, then crashed when attempting to
	// deref an invocation to getNameAsString(). The fix is to use
	// QualType().getAsString().
	//
	// Example:
	// std::string CastToName =
	// CastInfo ? CastInfo->to()->getAsCXXRecordDecl()->getNameAsString()
	// : CastToTy->getPointeeCXXRecordDecl()->getNameAsString();
	// Changed to:
	// std::string CastToName =
	// CastInfo ? CastInfo->to()->getAsCXXRecordDecl()->getNameAsString()
	// : CastToTy.getAsString();
	namespace llvm {
	template <typename, typename a> void isa(a &);
	template <typename> class PointerUnion {
	public:
	template <typename T> T *getAs() {
	(void)isa<int>(*this);
	return nullptr;
	}
	};
	class LLVMContext {
	PointerUnion<LLVMContext> c;
	void d() { c.getAs<int>(); }
	};
	} // namespace llvm