From 2f639b9f3c6b081f076d2ac6d75115ce44bfa249 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Fri, 24 Oct 2008 15:36:09 +0000
Subject: [PATCH] Semantic analysis for C++ reinterpret_cast and const_cast.
Patch by Sebastian Redl.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@58094 91177308-0d34-0410-b5e6-96231b3b80d8
---
include/clang/Basic/DiagnosticKinds.def | 19 ++
lib/Sema/Sema.cpp | 7 +
lib/Sema/Sema.h | 9 +
lib/Sema/SemaExpr.cpp | 2 +-
lib/Sema/SemaExprCXX.cpp | 339 ++++++++++++++++++-
lib/Sema/SemaType.cpp | 2 +-
test/SemaCXX/const-cast.cpp | 56 +++
test/SemaCXX/reinterpret-cast.cpp | 72 ++++
test/SemaCXX/reinterpret-fn-obj-pedantic.cpp | 9 +
9 files changed, 507 insertions(+), 8 deletions(-)
create mode 100644 test/SemaCXX/const-cast.cpp
create mode 100644 test/SemaCXX/reinterpret-cast.cpp
create mode 100644 test/SemaCXX/reinterpret-fn-obj-pedantic.cpp
diff --git a/include/clang/Basic/DiagnosticKinds.def b/include/clang/Basic/DiagnosticKinds.def
index f4e791ca918..342378ecbf9 100644
--- a/include/clang/Basic/DiagnosticKinds.def
+++ b/include/clang/Basic/DiagnosticKinds.def
@@ -1051,6 +1051,25 @@ DIAG(err_builtin_direct_init_more_than_one_arg, ERROR,
"initializer of a builtin type can only take one argument")
DIAG(err_value_init_for_array_type, ERROR,
"array types cannot be value-initialized")
+
+// C++ casts
+DIAG(err_bad_cxx_cast_generic, ERROR,
+ "%0 from '%2' to '%1' is not allowed")
+DIAG(err_bad_cxx_cast_rvalue, ERROR,
+ "%0 from rvalue to reference type '%1'")
+DIAG(err_bad_cxx_cast_const_away, ERROR,
+ "%0 from '%2' to '%1' casts away constness")
+DIAG(err_bad_const_cast_dest, ERROR,
+ "const_cast to '%0', which is not a reference, pointer-to-object, "
+ "or pointer-to-data-member")
+DIAG(err_bad_reinterpret_cast_same_type, ERROR,
+ "source and destination type of reinterpret_cast are not distinct")
+DIAG(ext_reinterpret_cast_fn_obj, EXTENSION,
+ "reinterpret_cast between pointer-to-function and pointer-to-object is "
+ "an extension")
+DIAG(err_bad_reinterpret_cast_small_int, ERROR,
+ "cast from pointer to smaller type '%0' loses information")
+
DIAG(err_invalid_use_of_function_type, ERROR,
"a function type is not allowed here")
DIAG(err_invalid_use_of_array_type, ERROR,
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index 21134177537..c2a8c5cd647 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -181,6 +181,13 @@ bool Sema::Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg1,
return true;
}
+bool Sema::Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg1,
+ const std::string &Msg2, const std::string &Msg3) {
+ std::string MsgArr[] = { Msg1, Msg2, Msg3 };
+ PP.getDiagnostics().Report(PP.getFullLoc(Loc), DiagID, MsgArr, 3);
+ return true;
+}
+
bool Sema::Diag(SourceLocation Loc, unsigned DiagID, const SourceRange& Range) {
PP.getDiagnostics().Report(PP.getFullLoc(Loc), DiagID, 0, 0, &Range,1);
return true;
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index ba07a9c174e..ab5b7b0b009 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -231,6 +231,8 @@ public:
bool Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg);
bool Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg1,
const std::string &Msg2);
+ bool Diag(SourceLocation Loc, unsigned DiagId, const std::string &Msg1,
+ const std::string &Msg2, const std::string &Msg3);
/// More expressive diagnostic helpers for expressions (say that 6 times:-)
bool Diag(SourceLocation Loc, unsigned DiagID, const SourceRange& R1);
@@ -699,6 +701,13 @@ public:
SourceLocation LParenLoc, ExprTy *E,
SourceLocation RParenLoc);
+ // Helpers for ActOnCXXCasts
+ bool CastsAwayConstness(QualType SrcType, QualType DestType);
+ void CheckConstCast(SourceLocation OpLoc, Expr *&SrcExpr, QualType DestType);
+ void CheckReinterpretCast(SourceLocation OpLoc, Expr *&SrcExpr,
+ QualType DestType);
+ void CheckStaticCast(SourceLocation OpLoc, Expr *&SrcExpr, QualType DestType);
+
//// ActOnCXXThis - Parse 'this' pointer.
virtual ExprResult ActOnCXXThis(SourceLocation ThisLoc);
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index ecc8e240c74..9b1543f7901 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -1802,7 +1802,7 @@ Sema::CheckSingleAssignmentConstraints(QualType lhsType, Expr *&rExpr) {
// DeclExpr's (created by ActOnIdentifierExpr), it would mess up the unary
// expressions that surpress this implicit conversion (&, sizeof).
//
- // Suppress this for references: C99 8.5.3p5. FIXME: revisit when references
+ // Suppress this for references: C++ 8.5.3p5. FIXME: revisit when references
// are better understood.
if (!lhsType->isReferenceType())
DefaultFunctionArrayConversion(rExpr);
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index c206e1a9cdd..5c62a936f19 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -17,6 +17,8 @@
#include "clang/Parse/DeclSpec.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Basic/Diagnostic.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Debug.h"
using namespace clang;
/// ActOnCXXCasts - Parse {dynamic,static,reinterpret,const}_cast's.
@@ -27,22 +29,347 @@ Sema::ActOnCXXCasts(SourceLocation OpLoc, tok::TokenKind Kind,
SourceLocation LParenLoc, ExprTy *E,
SourceLocation RParenLoc) {
CXXCastExpr::Opcode Op;
+ Expr *Ex = (Expr*)E;
+ QualType DestType = QualType::getFromOpaquePtr(Ty);
switch (Kind) {
default: assert(0 && "Unknown C++ cast!");
- case tok::kw_const_cast: Op = CXXCastExpr::ConstCast; break;
- case tok::kw_dynamic_cast: Op = CXXCastExpr::DynamicCast; break;
- case tok::kw_reinterpret_cast: Op = CXXCastExpr::ReinterpretCast; break;
- case tok::kw_static_cast: Op = CXXCastExpr::StaticCast; break;
+ case tok::kw_const_cast:
+ Op = CXXCastExpr::ConstCast;
+ CheckConstCast(OpLoc, Ex, DestType);
+ break;
+ case tok::kw_dynamic_cast:
+ Op = CXXCastExpr::DynamicCast;
+ break;
+ case tok::kw_reinterpret_cast:
+ Op = CXXCastExpr::ReinterpretCast;
+ CheckReinterpretCast(OpLoc, Ex, DestType);
+ break;
+ case tok::kw_static_cast:
+ Op = CXXCastExpr::StaticCast;
+ break;
}
- return new CXXCastExpr(Op, QualType::getFromOpaquePtr(Ty), (Expr*)E, OpLoc);
+ return new CXXCastExpr(Op, DestType, Ex, OpLoc);
+}
+
+/// CheckConstCast - Check that a const_cast\<DestType\>(SrcExpr) is valid.
+/// Refer to C++ 5.2.11 for details. const_cast is typically used in code
+/// like this:
+/// const char *str = "literal";
+/// legacy_function(const_cast\<char*\>(str));
+void
+Sema::CheckConstCast(SourceLocation OpLoc, Expr *&SrcExpr, QualType DestType)
+{
+ QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
+
+ DestType = Context.getCanonicalType(DestType);
+ QualType SrcType = SrcExpr->getType();
+ if (const ReferenceType *DestTypeTmp = DestType->getAsReferenceType()) {
+ if (SrcExpr->isLvalue(Context) != Expr::LV_Valid) {
+ // Cannot cast non-lvalue to reference type.
+ Diag(OpLoc, diag::err_bad_cxx_cast_rvalue,
+ "const_cast", OrigDestType.getAsString());
+ return;
+ }
+
+ // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
+ // [...] if a pointer to T1 can be [cast] to the type pointer to T2.
+ DestType = Context.getPointerType(DestTypeTmp->getPointeeType());
+ if (const ReferenceType *SrcTypeTmp = SrcType->getAsReferenceType()) {
+ // FIXME: This shouldn't actually be possible, but right now it is.
+ SrcType = SrcTypeTmp->getPointeeType();
+ }
+ SrcType = Context.getPointerType(SrcType);
+ } else {
+ // C++ 5.2.11p1: Otherwise, the result is an rvalue and the
+ // lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
+ // conversions are performed on the expression.
+ DefaultFunctionArrayConversion(SrcExpr);
+ SrcType = SrcExpr->getType();
+ }
+
+ if (!DestType->isPointerType()) {
+ // Cannot cast to non-pointer, non-reference type. Note that, if DestType
+ // was a reference type, we converted it to a pointer above.
+ // C++ 5.2.11p3: For two pointer types [...]
+ Diag(OpLoc, diag::err_bad_const_cast_dest, OrigDestType.getAsString());
+ return;
+ }
+ if (DestType->isFunctionPointerType()) {
+ // Cannot cast direct function pointers.
+ // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
+ // T is the ultimate pointee of source and target type.
+ Diag(OpLoc, diag::err_bad_const_cast_dest, OrigDestType.getAsString());
+ return;
+ }
+ SrcType = Context.getCanonicalType(SrcType);
+
+ // Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
+ // completely equal.
+ // FIXME: const_cast should probably not be able to convert between pointers
+ // to different address spaces.
+ // C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
+ // in multi-level pointers may change, but the level count must be the same,
+ // as must be the final pointee type.
+ while (SrcType != DestType && UnwrapSimilarPointerTypes(SrcType, DestType)) {
+ SrcType = SrcType.getUnqualifiedType();
+ DestType = DestType.getUnqualifiedType();
+ }
+
+ // Doug Gregor said to disallow this until users complain.
+#if 0
+ // If we end up with constant arrays of equal size, unwrap those too. A cast
+ // from const int [N] to int (&)[N] is invalid by my reading of the
+ // standard, but g++ accepts it even with -ansi -pedantic.
+ // No more than one level, though, so don't embed this in the unwrap loop
+ // above.
+ const ConstantArrayType *SrcTypeArr, *DestTypeArr;
+ if ((SrcTypeArr = Context.getAsConstantArrayType(SrcType)) &&
+ (DestTypeArr = Context.getAsConstantArrayType(DestType)))
+ {
+ if (SrcTypeArr->getSize() != DestTypeArr->getSize()) {
+ // Different array sizes.
+ Diag(OpLoc, diag::err_bad_cxx_cast_generic, "const_cast",
+ OrigDestType.getAsString(), OrigSrcType.getAsString());
+ return;
+ }
+ SrcType = SrcTypeArr->getElementType().getUnqualifiedType();
+ DestType = DestTypeArr->getElementType().getUnqualifiedType();
+ }
+#endif
+
+ // Since we're dealing in canonical types, the remainder must be the same.
+ if (SrcType != DestType) {
+ // Cast between unrelated types.
+ Diag(OpLoc, diag::err_bad_cxx_cast_generic, "const_cast",
+ OrigDestType.getAsString(), OrigSrcType.getAsString());
+ return;
+ }
+}
+
+/// CheckReinterpretCast - Check that a reinterpret_cast\<DestType\>(SrcExpr) is
+/// valid.
+/// Refer to C++ 5.2.10 for details. reinterpret_cast is typically used in code
+/// like this:
+/// char *bytes = reinterpret_cast\<char*\>(int_ptr);
+void
+Sema::CheckReinterpretCast(SourceLocation OpLoc, Expr *&SrcExpr,
+ QualType DestType)
+{
+ QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
+
+ DestType = Context.getCanonicalType(DestType);
+ QualType SrcType = SrcExpr->getType();
+ if (const ReferenceType *DestTypeTmp = DestType->getAsReferenceType()) {
+ if (SrcExpr->isLvalue(Context) != Expr::LV_Valid) {
+ // Cannot cast non-lvalue to reference type.
+ Diag(OpLoc, diag::err_bad_cxx_cast_rvalue,
+ "reinterpret_cast", OrigDestType.getAsString());
+ return;
+ }
+
+ // C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
+ // same effect as the conversion *reinterpret_cast<T*>(&x) with the
+ // built-in & and * operators.
+ // This code does this transformation for the checked types.
+ DestType = Context.getPointerType(DestTypeTmp->getPointeeType());
+ if (const ReferenceType *SrcTypeTmp = SrcType->getAsReferenceType()) {
+ // FIXME: This shouldn't actually be possible, but right now it is.
+ SrcType = SrcTypeTmp->getPointeeType();
+ }
+ SrcType = Context.getPointerType(SrcType);
+ } else {
+ // C++ 5.2.10p1: [...] the lvalue-to-rvalue, array-to-pointer, and
+ // function-to-pointer standard conversions are performed on the
+ // expression v.
+ DefaultFunctionArrayConversion(SrcExpr);
+ SrcType = SrcExpr->getType();
+ }
+
+ // Canonicalize source for comparison.
+ SrcType = Context.getCanonicalType(SrcType);
+
+ bool destIsPtr = DestType->isPointerType();
+ bool srcIsPtr = SrcType->isPointerType();
+ if (!destIsPtr && !srcIsPtr) {
+ // Except for std::nullptr_t->integer, which is not supported yet, and
+ // lvalue->reference, which is handled above, at least one of the two
+ // arguments must be a pointer.
+ Diag(OpLoc, diag::err_bad_cxx_cast_generic, "reinterpret_cast",
+ OrigDestType.getAsString(), OrigSrcType.getAsString());
+ return;
+ }
+
+ if (SrcType == DestType) {
+ // C++ 5.2.10p2 has a note that mentions that, subject to all other
+ // restrictions, a cast to the same type is allowed. The intent is not
+ // entirely clear here, since all other paragraphs explicitly forbid casts
+ // to the same type. However, the behavior of compilers is pretty consistent
+ // on this point: allow same-type conversion if the involved are pointers,
+ // disallow otherwise.
+ return;
+ }
+
+ // Note: Clang treats enumeration types as integral types. If this is ever
+ // changed for C++, the additional check here will be redundant.
+ if (DestType->isIntegralType() && !DestType->isEnumeralType()) {
+ assert(srcIsPtr);
+ // C++ 5.2.10p4: A pointer can be explicitly converted to any integral
+ // type large enough to hold it.
+ if (Context.getTypeSize(SrcType) > Context.getTypeSize(DestType)) {
+ Diag(OpLoc, diag::err_bad_reinterpret_cast_small_int,
+ OrigDestType.getAsString());
+ }
+ return;
+ }
+
+ if (SrcType->isIntegralType() || SrcType->isEnumeralType()) {
+ assert(destIsPtr);
+ // C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
+ // converted to a pointer.
+ return;
+ }
+
+ if (!destIsPtr || !srcIsPtr) {
+ // With the valid non-pointer conversions out of the way, we can be even
+ // more stringent.
+ Diag(OpLoc, diag::err_bad_cxx_cast_generic, "reinterpret_cast",
+ OrigDestType.getAsString(), OrigSrcType.getAsString());
+ return;
+ }
+
+ // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
+ if (CastsAwayConstness(SrcType, DestType)) {
+ Diag(OpLoc, diag::err_bad_cxx_cast_const_away, "reinterpret_cast",
+ OrigDestType.getAsString(), OrigSrcType.getAsString());
+ return;
+ }
+
+ // Not casting away constness, so the only remaining check is for compatible
+ // pointer categories.
+
+ if (SrcType->isFunctionPointerType()) {
+ if (DestType->isFunctionPointerType()) {
+ // C++ 5.2.10p6: A pointer to a function can be explicitly converted to
+ // a pointer to a function of a different type.
+ return;
+ }
+
+ // FIXME: Handle member pointers.
+
+ // C++0x 5.2.10p8: Converting a pointer to a function into a pointer to
+ // an object type or vice versa is conditionally-supported.
+ // Compilers support it in C++03 too, though, because it's necessary for
+ // casting the return value of dlsym() and GetProcAddress().
+ // FIXME: Conditionally-supported behavior should be configurable in the
+ // TargetInfo or similar.
+ if (!getLangOptions().CPlusPlus0x) {
+ Diag(OpLoc, diag::ext_reinterpret_cast_fn_obj);
+ }
+ return;
+ }
+
+ // FIXME: Handle member pointers.
+
+ if (DestType->isFunctionPointerType()) {
+ // See above.
+ if (!getLangOptions().CPlusPlus0x) {
+ Diag(OpLoc, diag::ext_reinterpret_cast_fn_obj);
+ }
+ return;
+ }
+
+ // C++ 5.2.10p7: A pointer to an object can be explicitly converted to
+ // a pointer to an object of different type.
+ // Void pointers are not specified, but supported by every compiler out there.
+ // So we finish by allowing everything that remains - it's got to be two
+ // object pointers.
+}
+
+/// Check if the pointer conversion from SrcType to DestType casts away
+/// constness as defined in C++ 5.2.11p8ff. This is used by the cast checkers.
+/// Both arguments must denote pointer types.
+bool
+Sema::CastsAwayConstness(QualType SrcType, QualType DestType)
+{
+ // Casting away constness is defined in C++ 5.2.11p8 with reference to
+ // C++ 4.4.
+ // We piggyback on Sema::IsQualificationConversion for this, since the rules
+ // are non-trivial. So first we construct Tcv *...cv* as described in
+ // C++ 5.2.11p8.
+ SrcType = Context.getCanonicalType(SrcType);
+ DestType = Context.getCanonicalType(DestType);
+
+ QualType UnwrappedSrcType = SrcType, UnwrappedDestType = DestType;
+ llvm::SmallVector<unsigned, 8> cv1, cv2;
+
+ // Find the qualifications.
+ while (UnwrapSimilarPointerTypes(UnwrappedSrcType, UnwrappedDestType)) {
+ cv1.push_back(UnwrappedSrcType.getCVRQualifiers());
+ cv2.push_back(UnwrappedDestType.getCVRQualifiers());
+ }
+ assert(cv1.size() > 0 && "Must have at least one pointer level.");
+
+ // Construct void pointers with those qualifiers (in reverse order of
+ // unwrapping, of course).
+ QualType SrcConstruct = Context.VoidTy;
+ QualType DestConstruct = Context.VoidTy;
+ for (llvm::SmallVector<unsigned, 8>::reverse_iterator i1 = cv1.rbegin(),
+ i2 = cv2.rbegin();
+ i1 != cv1.rend(); ++i1, ++i2)
+ {
+ SrcConstruct = Context.getPointerType(SrcConstruct.getQualifiedType(*i1));
+ DestConstruct = Context.getPointerType(DestConstruct.getQualifiedType(*i2));
+ }
+
+ // Test if they're compatible.
+ return SrcConstruct != DestConstruct &&
+ !IsQualificationConversion(SrcConstruct, DestConstruct);
+}
+
+/// CheckStaticCast - Check that a static_cast\<DestType\>(SrcExpr) is valid.
+void
+Sema::CheckStaticCast(SourceLocation OpLoc, Expr *&SrcExpr, QualType DestType)
+{
+#if 0
+ // 5.2.9/1 sets the ground rule of disallowing casting away constness.
+ // 5.2.9/2 permits everything allowed for direct-init, deferring to 8.5.
+ // Note: for class destination, that's overload resolution over dest's
+ // constructors. Src's conversions are only considered in overload choice.
+ // For any other destination, that's just the clause 4 standards convs.
+ // 5.2.9/4 permits static_cast<cv void>(anything), which is a no-op.
+ // 5.2.9/5 permits explicit non-dynamic downcasts for lvalue-to-reference.
+ // 5.2.9/6 permits reversing all implicit conversions except lvalue-to-rvalue,
+ // function-to-pointer, array decay and to-bool, with some further
+ // restrictions. Defers to 4.
+ // 5.2.9/7 permits integer-to-enum conversion. Interesting note: if the
+ // integer does not correspond to an enum value, the result is unspecified -
+ // but it still has to be some value of the enum. I don't think any compiler
+ // complies with that.
+ // 5.2.9/8 is 5.2.9/5 for pointers.
+ // 5.2.9/9 messes with member pointers. TODO. No need to think about that yet.
+ // 5.2.9/10 permits void* to T*.
+
+ QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
+ DestType = Context.getCanonicalType(DestType);
+ // Tests are ordered by simplicity and a wild guess at commonness.
+
+ if (const BuiltinType *BuiltinDest = DestType->getAsBuiltinType()) {
+ // 5.2.9/4
+ if (BuiltinDest->getKind() == BuiltinType::Void) {
+ return;
+ }
+
+ // Primitive conversions for 5.2.9/2 and 6.
+ }
+#endif
}
/// ActOnCXXBoolLiteral - Parse {true,false} literals.
Action::ExprResult
Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
- assert((Kind != tok::kw_true || Kind != tok::kw_false) &&
+ assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
"Unknown C++ Boolean value!");
return new CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc);
}
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 82e16cfc313..a12ec3ad7c8 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -541,7 +541,7 @@ QualType Sema::ObjCGetTypeForMethodDefinition(DeclTy *D) {
/// true. If T1 and T2 aren't pointer types or pointer-to-member
/// types, or if they are not similar at this level, returns false and
/// leaves T1 and T2 unchanged. Top-level qualifiers on T1 and T2 are
-/// ignord. This function will typically be called in a loop that
+/// ignored. This function will typically be called in a loop that
/// successively "unwraps" pointer and pointer-to-member types to
/// compare them at each level.
bool Sema::UnwrapSimilarPointerTypes(QualType& T1, QualType& T2)
diff --git a/test/SemaCXX/const-cast.cpp b/test/SemaCXX/const-cast.cpp
new file mode 100644
index 00000000000..90e8ed73789
--- /dev/null
+++ b/test/SemaCXX/const-cast.cpp
@@ -0,0 +1,56 @@
+// RUN: clang -fsyntax-only -verify %s
+
+// See if aliasing can confuse this baby.
+typedef char c;
+typedef c *cp;
+typedef cp *cpp;
+typedef cpp *cppp;
+typedef cppp &cpppr;
+typedef const cppp &cpppcr;
+typedef const char cc;
+typedef cc *ccp;
+typedef volatile ccp ccvp;
+typedef ccvp *ccvpp;
+typedef const volatile ccvpp ccvpcvp;
+typedef ccvpcvp *ccvpcvpp;
+typedef int iar[100];
+typedef iar &iarr;
+typedef int (*f)(int);
+
+char ***good_const_cast_test(ccvpcvpp var)
+{
+ // Cast away deep consts and volatiles.
+ char ***var2 = const_cast<cppp>(var);
+ char ***const &var3 = static_cast<cpppcr>(var2); // Different bug.
+ // Const reference to reference.
+ char ***&var4 = const_cast<cpppr>(var3);
+ // Drop reference. Intentionally without qualifier change.
+ char *** var5 = const_cast<cppp>(var4);
+ const int ar[100] = {0};
+ int (&rar)[100] = const_cast<iarr>(ar); // expected-warning {{statement was disambiguated as declaration}} expected-error {{const_cast from 'int const [100]' to 'iarr' is not allowed}}
+ // Array decay. Intentionally without qualifier change.
+ int *pi = const_cast<int*>(ar);
+ f fp = 0;
+ // Don't misidentify fn** as a function pointer.
+ f *fpp = const_cast<f*>(&fp);
+ return var4;
+}
+
+short *bad_const_cast_test(char const *volatile *const volatile *var)
+{
+ // Different pointer levels.
+ char **var2 = const_cast<char**>(var); // expected-error {{const_cast from 'char const *volatile *const volatile *' to 'char **' is not allowed}}
+ // Different final type.
+ short ***var3 = const_cast<short***>(var); // expected-error {{const_cast from 'char const *volatile *const volatile *' to 'short ***' is not allowed}}
+ // Rvalue to reference.
+ char ***&var4 = const_cast<cpppr>(&var2); // expected-error {{const_cast from rvalue to reference type 'cpppr'}}
+ // Non-pointer.
+ char v = const_cast<char>(**var2); // expected-error {{const_cast to 'char', which is not a reference, pointer-to-object, or pointer-to-data-member}}
+ const int *ar[100] = {0};
+ // Not even lenient g++ accepts this.
+ int *(*rar)[100] = const_cast<int *(*)[100]>(&ar); // expected-error {{const_cast from 'int const *(*)[100]' to 'int *(*)[100]' is not allowed}}
+ f fp1 = 0;
+ // Function pointers.
+ f fp2 = const_cast<f>(fp1); // expected-error {{const_cast to 'f', which is not a reference, pointer-to-object, or pointer-to-data-member}}
+ return **var3;
+}
diff --git a/test/SemaCXX/reinterpret-cast.cpp b/test/SemaCXX/reinterpret-cast.cpp
new file mode 100644
index 00000000000..6172c9f8d9e
--- /dev/null
+++ b/test/SemaCXX/reinterpret-cast.cpp
@@ -0,0 +1,72 @@
+// RUN: clang -fsyntax-only -verify %s
+
+enum test { testval = 1 };
+struct structure { int m; };
+typedef void (*fnptr)();
+
+// Test the conversion to self.
+void self_conversion()
+{
+ // T*->T* is allowed, T->T in general not.
+ int i = 0;
+ (void)reinterpret_cast<int>(i); // expected-error {{reinterpret_cast from 'int' to 'int' is not allowed}}
+ structure s;
+ (void)reinterpret_cast<structure>(s); // expected-error {{reinterpret_cast from 'struct structure' to 'struct structure' is not allowed}}
+ int *pi = 0;
+ (void)reinterpret_cast<int*>(pi);
+}
+
+// Test conversion between pointer and integral types, as in /3 and /4.
+void integral_conversion()
+{
+ void *vp = reinterpret_cast<void*>(testval);
+ long l = reinterpret_cast<long>(vp);
+ (void)reinterpret_cast<float*>(l);
+ fnptr fnp = reinterpret_cast<fnptr>(l);
+ (void)reinterpret_cast<char>(fnp); // expected-error {{cast from pointer to smaller type 'char' loses information}}
+ (void)reinterpret_cast<long>(fnp);
+}
+
+void pointer_conversion()
+{
+ int *p1 = 0;
+ float *p2 = reinterpret_cast<float*>(p1);
+ structure *p3 = reinterpret_cast<structure*>(p2);
+ typedef int **ppint;
+ ppint *deep = reinterpret_cast<ppint*>(p3);
+ (void)reinterpret_cast<fnptr*>(deep);
+}
+
+void constness()
+{
+ int ***const ipppc = 0;
+ // Valid: T1* -> T2 const*
+ int const *icp = reinterpret_cast<int const*>(ipppc);
+ // Invalid: T1 const* -> T2*
+ (void)reinterpret_cast<int*>(icp); // expected-error {{reinterpret_cast from 'int const *' to 'int *' casts away constness}}
+ // Invalid: T1*** -> T2 const* const**
+ int const *const **icpcpp = reinterpret_cast<int const* const**>(ipppc); // expected-error {{reinterpret_cast from 'int ***const' to 'int const *const **' casts away constness}}
+ // Valid: T1* -> T2*
+ int *ip = reinterpret_cast<int*>(icpcpp);
+ // Valid: T* -> T const*
+ (void)reinterpret_cast<int const*>(ip);
+ // Valid: T*** -> T2 const* const* const*
+ (void)reinterpret_cast<int const* const* const*>(ipppc);
+}
+
+void fnptrs()
+{
+ typedef int (*fnptr2)(int);
+ fnptr fp = 0;
+ (void)reinterpret_cast<fnptr2>(fp);
+ void *vp = reinterpret_cast<void*>(fp);
+ (void)reinterpret_cast<fnptr>(vp);
+}
+
+void refs()
+{
+ long l = 0;
+ char &c = reinterpret_cast<char&>(l);
+ // Bad: from rvalue
+ (void)reinterpret_cast<int&>(&c); // expected-error {{reinterpret_cast from rvalue to reference type 'int &'}}
+}
diff --git a/test/SemaCXX/reinterpret-fn-obj-pedantic.cpp b/test/SemaCXX/reinterpret-fn-obj-pedantic.cpp
new file mode 100644
index 00000000000..b39d1f0a69a
--- /dev/null
+++ b/test/SemaCXX/reinterpret-fn-obj-pedantic.cpp
@@ -0,0 +1,9 @@
+// RUN: clang -fsyntax-only -verify -std=c++98 -pedantic %s
+
+void fnptrs()
+{
+ typedef void (*fnptr)();
+ fnptr fp = 0;
+ void *vp = reinterpret_cast<void*>(fp); // expected-warning {{reinterpret_cast between pointer-to-function and pointer-to-object is an extension}}
+ (void)reinterpret_cast<fnptr>(vp); // expected-warning {{reinterpret_cast between pointer-to-function and pointer-to-object is an extension}}
+}
--
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