Make functional-style casts emit correct messages, and fix a crash-on-invalid.

llvm-svn: 77451

clang/lib/Parse/ParseExprCXX.cpp

@@ -516,6 +516,10 @@ Parser::ParseCXXTypeConstructExpression(const DeclSpec &DS) {
   // Match the ')'.
   SourceLocation RParenLoc = MatchRHSPunctuation(tok::r_paren, LParenLoc);
 
+  // TypeRep could be null, if it references an invalid typedef.
+  if (!TypeRep)
+    return ExprError();
+
   assert((Exprs.size() == 0 || Exprs.size()-1 == CommaLocs.size())&&
          "Unexpected number of commas!");
   return Actions.ActOnCXXTypeConstructExpr(DS.getSourceRange(), TypeRep,

clang/lib/Sema/Sema.h

@@ -3171,8 +3171,9 @@ public:
                           bool ForceRValue = false);
 
   /// CheckCastTypes - Check type constraints for casting between types under
-  /// C semantics.
-  bool CheckCastTypes(SourceRange TyRange, QualType CastTy, Expr *&CastExpr);
+  /// C semantics, or forward to CXXCheckCStyleCast in C++.
+  bool CheckCastTypes(SourceRange TyRange, QualType CastTy, Expr *&CastExpr,
+                      bool FunctionalStyle = false);
 
   // CheckVectorCast - check type constraints for vectors. 
   // Since vectors are an extension, there are no C standard reference for this.
@@ -3189,7 +3190,8 @@ public:
 
   /// CXXCheckCStyleCast - Check constraints of a C-style or function-style
   /// cast under C++ semantics.
-  bool CXXCheckCStyleCast(SourceRange R, QualType CastTy, Expr *&CastExpr);
+  bool CXXCheckCStyleCast(SourceRange R, QualType CastTy, Expr *&CastExpr,
+                          bool FunctionalStyle);
 
   /// CheckMessageArgumentTypes - Check types in an Obj-C message send. 
   /// \param Method - May be null.

clang/lib/Sema/SemaCXXCast.cpp

@@ -999,7 +999,8 @@ static TryCastResult TryReinterpretCast(Sema &Self, Expr *SrcExpr,
 }
 
 
-bool Sema::CXXCheckCStyleCast(SourceRange R, QualType CastTy, Expr *&CastExpr)
+bool Sema::CXXCheckCStyleCast(SourceRange R, QualType CastTy, Expr *&CastExpr,
+                              bool FunctionalStyle)
 {
   // This test is outside everything else because it's the only case where
   // a non-lvalue-reference target type does not lead to decay.
@@ -1036,9 +1037,8 @@ bool Sema::CXXCheckCStyleCast(SourceRange R, QualType CastTy, Expr *&CastExpr)
     }
   }
 
-  // FIXME: Differentiate functional-style and C-style cast.
   if (tcr != TC_Success && msg != 0)
-    Diag(R.getBegin(), msg) << CT_CStyle
+    Diag(R.getBegin(), msg) << (FunctionalStyle ? CT_Functional : CT_CStyle)
       << CastExpr->getType() << CastTy << R;
 
   return tcr != TC_Success;

clang/lib/Sema/SemaExpr.cpp

@@ -2918,9 +2918,10 @@ Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist,
 }
 
 /// CheckCastTypes - Check type constraints for casting between types.
-bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr) {
+bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr,
+                          bool FunctionalStyle) {
   if (getLangOptions().CPlusPlus)
-    return CXXCheckCStyleCast(TyR, castType, castExpr);
+    return CXXCheckCStyleCast(TyR, castType, castExpr, FunctionalStyle);
 
   UsualUnaryConversions(castExpr);
 

clang/lib/Sema/SemaExprCXX.cpp

@@ -203,7 +203,7 @@ Sema::ActOnCXXTypeConstructExpr(SourceRange TypeRange, TypeTy *TypeRep,
   // corresponding cast expression.
   //
   if (NumExprs == 1) {
-    if (CheckCastTypes(TypeRange, Ty, Exprs[0]))
+    if (CheckCastTypes(TypeRange, Ty, Exprs[0], /*functional-style*/true))
       return ExprError();
     exprs.release();
     return Owned(new (Context) CXXFunctionalCastExpr(Ty.getNonReferenceType(),

clang/test/SemaCXX/functional-cast.cpp

@@ -1,4 +1,6 @@
-// RUN: clang-cc -fsyntax-only -verify %s
+// RUN: clang-cc -fsyntax-only -verify -faccess-control %s
+
+// ------------ not interpreted as C-style cast ------------
 
 struct SimpleValueInit {
   int i;
@@ -25,3 +27,293 @@ void test_cxx_function_cast_multi() {
   (void)NoValueInit(0, 0, 0); // expected-error{{no matching constructor for initialization}}
   (void)int(1, 2); // expected-error{{function-style cast to a builtin type can only take one argument}}
 }
+
+
+// ------------------ everything else --------------------
+
+struct A {};
+
+// ----------- const_cast --------------
+
+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);
+
+void t_cc()
+{
+  ccvpcvpp var = 0;
+  // Cast away deep consts and volatiles.
+  char ***var2 = cppp(var);
+  char ***const &var3 = var2;
+  // Const reference to reference.
+  char ***&var4 = cpppr(var3);
+  // Drop reference. Intentionally without qualifier change.
+  char *** var5 = cppp(var4);
+  const int ar[100] = {0};
+  // Array decay. Intentionally without qualifier change.
+  typedef int *intp;
+  int *pi = intp(ar);
+  f fp = 0;
+  // Don't misidentify fn** as a function pointer.
+  typedef f *fp_t;
+  f *fpp = fp_t(&fp);
+  int const A::* const A::*icapcap = 0;
+  typedef int A::* A::*iapap_t;
+  iapap_t iapap = iapap_t(icapcap);
+}
+
+// ----------- static_cast -------------
+
+struct B : public A {};             // Single public base.
+struct C1 : public virtual B {};    // Single virtual base.
+struct C2 : public virtual B {};
+struct D : public C1, public C2 {}; // Diamond
+struct E : private A {};            // Single private base.
+struct F : public C1 {};            // Single path to B with virtual.
+struct G1 : public B {};
+struct G2 : public B {};
+struct H : public G1, public G2 {}; // Ambiguous path to B.
+
+enum Enum { En1, En2 };
+enum Onom { On1, On2 };
+
+struct Co1 { operator int(); };
+struct Co2 { Co2(int); };
+struct Co3 { };
+struct Co4 { Co4(Co3); operator Co3(); };
+
+// Explicit implicits
+void t_529_2()
+{
+  int i = 1;
+  (void)float(i);
+  double d = 1.0;
+  (void)float(d);
+  (void)int(d);
+  (void)char(i);
+  typedef unsigned long ulong;
+  (void)ulong(i);
+  (void)int(En1);
+  (void)double(En1);
+  typedef int &intr;
+  (void)intr(i);
+  typedef const int &cintr;
+  (void)cintr(i);
+
+  int ar[1];
+  typedef const int *cintp;
+  (void)cintp(ar);
+  typedef void (*pfvv)();
+  (void)pfvv(t_529_2);
+
+  typedef void *voidp;
+  (void)voidp(0);
+  (void)voidp((int*)0);
+  typedef volatile const void *vcvoidp;
+  (void)vcvoidp((const int*)0);
+  typedef A *Ap;
+  (void)Ap((B*)0);
+  typedef A &Ar;
+  (void)Ar(*((B*)0));
+  typedef const B *cBp;
+  (void)cBp((C1*)0);
+  typedef B &Br;
+  (void)Br(*((C1*)0));
+  (void)Ap((D*)0);
+  typedef const A &cAr;
+  (void)cAr(*((D*)0));
+  typedef int B::*Bmp;
+  (void)Bmp((int A::*)0);
+  typedef void (B::*Bmfp)();
+  (void)Bmfp((void (A::*)())0);
+  (void)Ap((E*)0); // functional-style cast ignores access control
+  (void)voidp((const int*)0); // const_cast appended
+
+  (void)int(Co1());
+  (void)Co2(1);
+  (void)Co3((Co4)(Co3()));
+
+  // Bad code below
+  //(void)(A*)((H*)0); // {{static_cast from 'struct H *' to 'struct A *' is not allowed}}
+}
+
+// Anything to void
+void t_529_4()
+{
+  void(1);
+  (void(t_529_4));
+}
+
+// Static downcasts
+void t_529_5_8()
+{
+  typedef B *Bp;
+  (void)Bp((A*)0);
+  typedef B &Br;
+  (void)Br(*((A*)0));
+  typedef const G1 *cG1p;
+  (void)cG1p((A*)0);
+  typedef const G1 &cG1r;
+  (void)cG1r(*((A*)0));
+  (void)Bp((const A*)0); // const_cast appended
+  (void)Br(*((const A*)0)); // const_cast appended
+  typedef E *Ep;
+  (void)Ep((A*)0); // access control ignored
+  typedef E &Er;
+  (void)Er(*((A*)0)); // access control ignored
+
+  // Bad code below
+
+  typedef C1 *C1p;
+  (void)C1p((A*)0); // expected-error {{cannot cast 'struct A *' to 'C1p' (aka 'struct C1 *') via virtual base 'struct B'}}
+  typedef C1 &C1r;
+  (void)C1r(*((A*)0)); // expected-error {{cannot cast 'struct A' to 'C1r' (aka 'struct C1 &') via virtual base 'struct B'}}
+  typedef D *Dp;
+  (void)Dp((A*)0); // expected-error {{cannot cast 'struct A *' to 'Dp' (aka 'struct D *') via virtual base 'struct B'}}
+  typedef D &Dr;
+  (void)Dr(*((A*)0)); // expected-error {{cannot cast 'struct A' to 'Dr' (aka 'struct D &') via virtual base 'struct B'}}
+  typedef H *Hp;
+  (void)Hp((A*)0); // expected-error {{ambiguous cast from base 'struct A' to derived 'struct H':\n    struct A -> struct B -> struct G1 -> struct H\n    struct A -> struct B -> struct G2 -> struct H}}
+  typedef H &Hr;
+  (void)Hr(*((A*)0)); // expected-error {{ambiguous cast from base 'struct A' to derived 'struct H':\n    struct A -> struct B -> struct G1 -> struct H\n    struct A -> struct B -> struct G2 -> struct H}}
+
+  // TODO: Test DR427. This requires user-defined conversions, though.
+}
+
+// Enum conversions
+void t_529_7()
+{
+  (void)Enum(1);
+  (void)Enum(1.0);
+  (void)Onom(En1);
+
+  // Bad code below
+
+  (void)Enum((int*)0); // expected-error {{functional-style cast from 'int *' to 'enum Enum' is not allowed}}
+}
+
+// Void pointer to object pointer
+void t_529_10()
+{
+  typedef int *intp;
+  (void)intp((void*)0);
+  typedef const A *cAp;
+  (void)cAp((void*)0);
+  (void)intp((const void*)0); // const_cast appended
+}
+
+// Member pointer upcast.
+void t_529_9()
+{
+  typedef int A::*Amp;
+  (void)Amp((int B::*)0);
+
+  // Bad code below
+  (void)Amp((int H::*)0); // expected-error {{ambiguous conversion from pointer to member of derived class 'struct H'}}
+  (void)Amp((int F::*)0); // expected-error {{conversion from pointer to member of class 'struct F'}}
+}
+
+// -------- reinterpret_cast -----------
+
+enum test { testval = 1 };
+struct structure { int m; };
+typedef void (*fnptr)();
+
+// Test conversion between pointer and integral types, as in p3 and p4.
+void integral_conversion()
+{
+  typedef void *voidp;
+  void *vp = voidp(testval);
+  long l = long(vp);
+  typedef float *floatp;
+  (void)floatp(l);
+  fnptr fnp = fnptr(l);
+  (void)char(fnp); // expected-error {{cast from pointer to smaller type 'char' loses information}}
+  (void)long(fnp);
+}
+
+void pointer_conversion()
+{
+  int *p1 = 0;
+  typedef float *floatp;
+  float *p2 = floatp(p1);
+  typedef structure *structurep;
+  structure *p3 = structurep(p2);
+  typedef int **ppint;
+  typedef ppint *pppint;
+  ppint *deep = pppint(p3);
+  typedef fnptr fnptrp;
+  (void)fnptrp(deep);
+}
+
+void constness()
+{
+  int ***const ipppc = 0;
+  typedef int const *icp_t;
+  int const *icp = icp_t(ipppc);
+  typedef int *intp;
+  (void)intp(icp); // const_cast appended
+  typedef int const *const ** intcpcpp;
+  intcpcpp icpcpp = intcpcpp(ipppc); // const_cast appended
+  int *ip = intp(icpcpp);
+  (void)icp_t(ip);
+  typedef int const *const *const *intcpcpcp;
+  (void)intcpcpcp(ipppc);
+}
+
+void fnptrs()
+{
+  typedef int (*fnptr2)(int);
+  fnptr fp = 0;
+  (void)fnptr2(fp);
+  typedef void *voidp;
+  void *vp = voidp(fp);
+  (void)fnptr(vp);
+}
+
+void refs()
+{
+  long l = 0;
+  typedef char &charr;
+  char &c = charr(l);
+  // Bad: from rvalue
+  typedef int &intr;
+  (void)intr(&c); // expected-error {{functional-style cast from rvalue to reference type 'intr' (aka 'int &')}}
+}
+
+void memptrs()
+{
+  const int structure::*psi = 0;
+  typedef const float structure::*structurecfmp;
+  (void)structurecfmp(psi);
+  typedef int structure::*structureimp;
+  (void)structureimp(psi); // const_cast appended
+
+  void (structure::*psf)() = 0;
+  typedef int (structure::*structureimfp)();
+  (void)structureimfp(psf);
+
+  typedef void (structure::*structurevmfp)();
+  (void)structurevmfp(psi); // expected-error {{functional-style cast from 'int const struct structure::*' to 'structurevmfp' (aka 'void (struct structure::*)()') is not allowed}}
+  (void)structureimp(psf); // expected-error {{functional-style cast from 'void (struct structure::*)()' to 'structureimp' (aka 'int struct structure::*') is not allowed}}
+}
+
+// ---------------- misc ------------------
+
+void crash_on_invalid_1()
+{
+  typedef itn Typo; // expected-error {{unknown type name 'itn'}}
+  (void)Typo(1); // used to crash
+}

clang/test/SemaTemplate/instantiate-cast.cpp

@@ -89,7 +89,7 @@ template struct ConstCast0<int const *, float *>; // expected-note{{instantiatio
 template<typename T, typename U>
 struct FunctionalCast1 {
   void f(T t) {
-    (void)U(t); // expected-error{{C-style cast from 'struct A' to 'int'}}
+    (void)U(t); // expected-error{{functional-style cast from 'struct A' to 'int'}}
   }
 };