[cfe-commits] [PATCH] Encoding calling conventions in FunctionTypes
Charles Davis
cdavis at mymail.mines.edu
Mon Dec 21 19:01:48 PST 2009
Douglas Gregor wrote:
> On Dec 16, 2009, at 1:12 PM, Charles Davis wrote:
>
>> Hi,
>>
>> This patch encodes calling conventions into FunctionType objects. Right
>> now, only cdecl, stdcall, and fastcall are supported. No real users yet,
>> but I went through and fixed all the users of
>> ASTContext::getFunctionType() and friends to respect the calling
>> convention.
>>
>> Next up: applying calling convention attributes to the function types.
>
> Comments below.
How's the attached patch? (Responses to particular comments below.)
>
>> Index: include/clang/AST/ASTContext.h
>> ===================================================================
>> --- include/clang/AST/ASTContext.h (revision 91549)
>> +++ include/clang/AST/ASTContext.h (working copy)
>> @@ -399,6 +399,11 @@
>> /// BlockPointer.
>> QualType getNoReturnType(QualType T, bool AddNoReturn = true);
>>
>> + /// getCallConvType - Adds the specified calling convention
>> attribute to
>> + /// the given type, which must be a FunctionType or a pointer to an
>> + /// allowable type.
>> + QualType getCallConvType(QualType T, unsigned CallConv);
>> +
>
> The calling convention needs to be an enumeration (defined in Type.h)
> rather than just an "unsigned". We're only likely to support a few
> calling conventions, and adding new ones will be a non-trivial undertaking.
Done.
>
>> /// getComplexType - Return the uniqued reference to the type for a
>> complex
>> /// number with the specified element type.
>> QualType getComplexType(QualType T);
>> @@ -515,7 +520,8 @@
>>
>> /// getFunctionNoProtoType - Return a K&R style C function type like
>> 'int()'.
>> ///
>> - QualType getFunctionNoProtoType(QualType ResultTy, bool NoReturn =
>> false);
>> + QualType getFunctionNoProtoType(QualType ResultTy, bool NoReturn =
>> false,
>> + unsigned CallConv = 0);
>>
>> /// getFunctionType - Return a normal function type with a typed
>> argument
>> /// list. isVariadic indicates whether the argument list includes
>> '...'.
>> @@ -524,7 +530,7 @@
>> unsigned TypeQuals, bool hasExceptionSpec =
>> false,
>> bool hasAnyExceptionSpec = false,
>> unsigned NumExs = 0, const QualType
>> *ExArray = 0,
>> - bool NoReturn = false);
>> + bool NoReturn = false, unsigned CallConv =
>> 0);
>>
>> /// getTypeDeclType - Return the unique reference to the type for
>> /// the specified type declaration.
>> Index: include/clang/AST/Type.h
>> ===================================================================
>> --- include/clang/AST/Type.h (revision 91549)
>> +++ include/clang/AST/Type.h (working copy)
>> @@ -1708,21 +1708,26 @@
>> /// NoReturn - Indicates if the function type is attribute noreturn.
>> unsigned NoReturn : 1;
>>
>> + /// CallConv - The calling convention used by the function. Is 0
>> + /// for default, 1 for C, 2 for stdcall, and 3 for fastcall.
>> + unsigned CallConv : 2;
>> +
>> // The type returned by the function.
>> QualType ResultType;
>> protected:
>> FunctionType(TypeClass tc, QualType res, bool SubclassInfo,
>> unsigned typeQuals, QualType Canonical, bool Dependent,
>> - bool noReturn = false)
>> + bool noReturn = false, unsigned callConv = 0)
>> : Type(tc, Canonical, Dependent),
>> SubClassData(SubclassInfo), TypeQuals(typeQuals),
>> NoReturn(noReturn),
>> - ResultType(res) {}
>> + CallConv(callConv), ResultType(res) {}
>> bool getSubClassData() const { return SubClassData; }
>> unsigned getTypeQuals() const { return TypeQuals; }
>> public:
>>
>> QualType getResultType() const { return ResultType; }
>> bool getNoReturnAttr() const { return NoReturn; }
>> + unsigned getCallConv() const { return CallConv; }
>
> Any change to one of the ASTs requires a (de-)serialization code for
> Clang's precompiled headers. PCHWriter.cpp and PCHReader.cpp will need
> to be updated to include the calling convention.
Are you sure? I looked at PCHWriter.cpp, and I didn't see any special
handling for the noreturn attribute, even when it's stored as part of
the type. It looks like PCHWriter just stores the noreturn attribute
itself into the PCH.
>
> Also, when you get to applying calling convention attributes to function
> types, please make sure to update the type printer as well.
Will do.
>
>> static bool classof(const Type *T) {
>> return T->getTypeClass() == FunctionNoProto ||
>> @@ -1735,9 +1740,9 @@
>> /// no information available about its arguments.
>> class FunctionNoProtoType : public FunctionType, public
>> llvm::FoldingSetNode {
>> FunctionNoProtoType(QualType Result, QualType Canonical,
>> - bool NoReturn = false)
>> + bool NoReturn = false, unsigned CallConv = 0)
>> : FunctionType(FunctionNoProto, Result, false, 0, Canonical,
>> - /*Dependent=*/false, NoReturn) {}
>> + /*Dependent=*/false, NoReturn, CallConv) {}
>> friend class ASTContext; // ASTContext creates these.
>> public:
>> // No additional state past what FunctionType provides.
>> @@ -1779,10 +1784,12 @@
>> FunctionProtoType(QualType Result, const QualType *ArgArray,
>> unsigned numArgs,
>> bool isVariadic, unsigned typeQuals, bool hasExs,
>> bool hasAnyExs, const QualType *ExArray,
>> - unsigned numExs, QualType Canonical, bool NoReturn)
>> + unsigned numExs, QualType Canonical, bool NoReturn,
>> + unsigned CallConv = 0)
>> : FunctionType(FunctionProto, Result, isVariadic, typeQuals,
>> Canonical,
>> (Result->isDependentType() ||
>> - hasAnyDependentType(ArgArray, numArgs)), NoReturn),
>> + hasAnyDependentType(ArgArray, numArgs)), NoReturn,
>> + CallConv),
>> NumArgs(numArgs), NumExceptions(numExs), HasExceptionSpec(hasExs),
>> AnyExceptionSpec(hasAnyExs) {
>> // Fill in the trailing argument array.
>> Index: lib/Sema/SemaTemplateInstantiateDecl.cpp
>> ===================================================================
>> --- lib/Sema/SemaTemplateInstantiateDecl.cpp (revision 91549)
>> +++ lib/Sema/SemaTemplateInstantiateDecl.cpp (working copy)
>> @@ -1523,7 +1523,8 @@
>>
>> Proto->hasAnyExceptionSpec(),
>> Exceptions.size(),
>> Exceptions.data(),
>> -
>> Proto->getNoReturnAttr()));
>> +
>> Proto->getNoReturnAttr(),
>> + Proto->getCallConv()));
>> }
>>
>> return false;
>> Index: lib/AST/ASTContext.cpp
>> ===================================================================
>> --- lib/AST/ASTContext.cpp (revision 91549)
>> +++ lib/AST/ASTContext.cpp (working copy)
>> @@ -1222,7 +1222,8 @@
>> return T;
>>
>> if (const FunctionNoProtoType *FNPT =
>> dyn_cast<FunctionNoProtoType>(F)) {
>> - ResultType = getFunctionNoProtoType(FNPT->getResultType(),
>> AddNoReturn);
>> + ResultType = getFunctionNoProtoType(FNPT->getResultType(),
>> AddNoReturn,
>> + FNPT->getCallConv());
>> } else {
>> const FunctionProtoType *FPT = cast<FunctionProtoType>(F);
>> ResultType
>> @@ -1231,7 +1232,7 @@
>> FPT->getTypeQuals(),
>> FPT->hasExceptionSpec(),
>> FPT->hasAnyExceptionSpec(),
>> FPT->getNumExceptions(),
>> FPT->exception_begin(),
>> - AddNoReturn);
>> + AddNoReturn, FPT->getCallConv());
>> }
>> } else
>> return T;
>> @@ -1239,6 +1240,38 @@
>> return getQualifiedType(ResultType, T.getLocalQualifiers());
>> }
>>
>> +QualType ASTContext::getCallConvType(QualType T, unsigned CallConv) {
>> + QualType ResultType;
>> + if (const PointerType *Pointer = T->getAs<PointerType>()) {
>> + QualType Pointee = Pointer->getPointeeType();
>> + ResultType = getCallConvType(Pointee, CallConv);
>> + if (ResultType == Pointee)
>> + return T;
>> +
>> + ResultType = getPointerType(ResultType);
>> + } else if (const FunctionType *F = T->getAs<FunctionType>()) {
>> + if (F->getCallConv() == CallConv)
>> + return T;
>> +
>> + if (const FunctionNoProtoType *FNPT =
>> dyn_cast<FunctionNoProtoType>(F)) {
>> + ResultType = getFunctionNoProtoType(FNPT->getResultType(),
>> + FNPT->getNoReturn(),
>> CallConv);
>> + } else {
>> + const FunctionProtoType *FPT = cast<FunctionProtoType>(F);
>> + ResultType
>> + = getFunctionType(FPT->getResultType(), FPT->arg_type_begin(),
>> + FPT->getNumArgs(), FPT->isVariadic(),
>> + FPT->getTypeQuals(),
>> + FPT->hasExceptionSpec(),
>> FPT->hasAnyExceptionSpec(),
>> + FPT->getNumExceptions(),
>> FPT->exception_begin(),
>> + FPT->getNoReturn(), CallConv);
>> + }
>> + } else
>> + return T;
>> +
>> + return getQualifiedType(ResultType, T.getLocalQualifiers());
>> +}
>
> It's really unfortunate that this code is nearly a copy of
> getNoReturnType. Is there a way to consolidate the two?
Took me a while, but I found one. The problem was that, when I called
the common function from getNoReturnType() (or its brother
getCallConvType()), I needed a default value for the attribute I wasn't
setting. The obvious place to get it from would be from the type itself,
but then there's the case where the get*Type() methods get called on
something that isn't a function type. So I added a method to QualType
that does the check and grabs the calling convention from the FunctionType.
>
>> /// getComplexType - Return the uniqued reference to the type for a
>> complex
>> /// number with the specified element type.
>> QualType ASTContext::getComplexType(QualType T) {
>> @@ -1690,7 +1723,8 @@
>>
>> /// getFunctionNoProtoType - Return a K&R style C function type like
>> 'int()'.
>> ///
>> -QualType ASTContext::getFunctionNoProtoType(QualType ResultTy, bool
>> NoReturn) {
>> +QualType ASTContext::getFunctionNoProtoType(QualType ResultTy, bool
>> NoReturn,
>> + unsigned CallConv) {
>> // Unique functions, to guarantee there is only one function of a
>> particular
>> // structure.
>> llvm::FoldingSetNodeID ID;
>> @@ -1703,7 +1737,8 @@
>>
>> QualType Canonical;
>> if (!ResultTy.isCanonical()) {
>> - Canonical = getFunctionNoProtoType(getCanonicalType(ResultTy),
>> NoReturn);
>> + Canonical = getFunctionNoProtoType(getCanonicalType(ResultTy),
>> NoReturn,
>> + CallConv);
>>
>> // Get the new insert position for the node we care about.
>> FunctionNoProtoType *NewIP =
>> @@ -1724,7 +1759,8 @@
>> unsigned NumArgs, bool isVariadic,
>> unsigned TypeQuals, bool
>> hasExceptionSpec,
>> bool hasAnyExceptionSpec,
>> unsigned NumExs,
>> - const QualType *ExArray, bool
>> NoReturn) {
>> + const QualType *ExArray, bool
>> NoReturn,
>> + unsigned CallConv) {
>> // Unique functions, to guarantee there is only one function of a
>> particular
>> // structure.
>> llvm::FoldingSetNodeID ID;
>> @@ -1755,7 +1791,7 @@
>> Canonical = getFunctionType(getCanonicalType(ResultTy),
>> CanonicalArgs.data(), NumArgs,
>> isVariadic, TypeQuals, false,
>> - false, 0, 0, NoReturn);
>> + false, 0, 0, NoReturn, CallConv);
>>
>> // Get the new insert position for the node we care about.
>> FunctionProtoType *NewIP =
>> @@ -1772,7 +1808,7 @@
>> NumExs*sizeof(QualType), TypeAlignment);
>> new (FTP) FunctionProtoType(ResultTy, ArgArray, NumArgs, isVariadic,
>> TypeQuals, hasExceptionSpec,
>> hasAnyExceptionSpec,
>> - ExArray, NumExs, Canonical, NoReturn);
>> + ExArray, NumExs, Canonical, NoReturn,
>> CallConv);
>> Types.push_back(FTP);
>> FunctionProtoTypes.InsertNode(FTP, InsertPos);
>> return QualType(FTP, 0);
>> @@ -4213,6 +4249,11 @@
>> allLTypes = false;
>> if (NoReturn != rbase->getNoReturnAttr())
>> allRTypes = false;
>> + unsigned lcc = lbase->getCallConv();
>> + unsigned rcc = rbase->getCallConv();
>> + // Compatible functions must have the same calling convention
>> + if((lcc == 0 || rcc != 0) && lcc != rcc)
>> + return QualType();
>>
>> if (lproto && rproto) { // two C99 style function prototypes
>> assert(!lproto->hasExceptionSpec() && !rproto->hasExceptionSpec() &&
>> @@ -4248,7 +4289,7 @@
>> if (allRTypes) return rhs;
>> return getFunctionType(retType, types.begin(), types.size(),
>> lproto->isVariadic(), lproto->getTypeQuals(),
>> - NoReturn);
>> + NoReturn, lcc);
>> }
>>
>> if (lproto) allRTypes = false;
>> @@ -4275,12 +4316,12 @@
>> if (allRTypes) return rhs;
>> return getFunctionType(retType, proto->arg_type_begin(),
>> proto->getNumArgs(), proto->isVariadic(),
>> - proto->getTypeQuals(), NoReturn);
>> + proto->getTypeQuals(), NoReturn, lcc);
>> }
>>
>> if (allLTypes) return lhs;
>> if (allRTypes) return rhs;
>> - return getFunctionNoProtoType(retType, NoReturn);
>> + return getFunctionNoProtoType(retType, NoReturn, lcc);
>> }
>>
>> QualType ASTContext::mergeTypes(QualType LHS, QualType RHS) {
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>
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