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SemaChecking.cpp
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SemaChecking.cpp
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//===- SemaChecking.cpp - Extra Semantic Checking -------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements extra semantic analysis beyond what is enforced
// by the C type system.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/APValue.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
#include "clang/AST/AttrIterator.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclBase.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclarationName.h"
#include "clang/AST/EvaluatedExprVisitor.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/ExprOpenMP.h"
#include "clang/AST/FormatString.h"
#include "clang/AST/NSAPI.h"
#include "clang/AST/NonTrivialTypeVisitor.h"
#include "clang/AST/OperationKinds.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/TemplateBase.h"
#include "clang/AST/Type.h"
#include "clang/AST/TypeLoc.h"
#include "clang/AST/UnresolvedSet.h"
#include "clang/Basic/AddressSpaces.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/OpenCLOptions.h"
#include "clang/Basic/OperatorKinds.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/Specifiers.h"
#include "clang/Basic/SyncScope.h"
#include "clang/Basic/TargetBuiltins.h"
#include "clang/Basic/TargetCXXABI.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Basic/TypeTraits.h"
#include "clang/Lex/Lexer.h" // TODO: Extract static functions to fix layering.
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/Ownership.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/Sema.h"
#include "clang/Sema/SemaInternal.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Support/AtomicOrdering.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/Locale.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cstddef>
#include <cstdint>
#include <functional>
#include <limits>
#include <string>
#include <tuple>
#include <utility>
using namespace clang;
using namespace sema;
SourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL,
unsigned ByteNo) const {
return SL->getLocationOfByte(ByteNo, getSourceManager(), LangOpts,
Context.getTargetInfo());
}
/// Checks that a call expression's argument count is the desired number.
/// This is useful when doing custom type-checking. Returns true on error.
static bool checkArgCount(Sema &S, CallExpr *call, unsigned desiredArgCount) {
unsigned argCount = call->getNumArgs();
if (argCount == desiredArgCount) return false;
if (argCount < desiredArgCount)
return S.Diag(call->getEndLoc(), diag::err_typecheck_call_too_few_args)
<< 0 /*function call*/ << desiredArgCount << argCount
<< call->getSourceRange();
// Highlight all the excess arguments.
SourceRange range(call->getArg(desiredArgCount)->getBeginLoc(),
call->getArg(argCount - 1)->getEndLoc());
return S.Diag(range.getBegin(), diag::err_typecheck_call_too_many_args)
<< 0 /*function call*/ << desiredArgCount << argCount
<< call->getArg(1)->getSourceRange();
}
/// Check that the first argument to __builtin_annotation is an integer
/// and the second argument is a non-wide string literal.
static bool SemaBuiltinAnnotation(Sema &S, CallExpr *TheCall) {
if (checkArgCount(S, TheCall, 2))
return true;
// First argument should be an integer.
Expr *ValArg = TheCall->getArg(0);
QualType Ty = ValArg->getType();
if (!Ty->isIntegerType()) {
S.Diag(ValArg->getBeginLoc(), diag::err_builtin_annotation_first_arg)
<< ValArg->getSourceRange();
return true;
}
// Second argument should be a constant string.
Expr *StrArg = TheCall->getArg(1)->IgnoreParenCasts();
StringLiteral *Literal = dyn_cast<StringLiteral>(StrArg);
if (!Literal || !Literal->isAscii()) {
S.Diag(StrArg->getBeginLoc(), diag::err_builtin_annotation_second_arg)
<< StrArg->getSourceRange();
return true;
}
TheCall->setType(Ty);
return false;
}
static bool SemaBuiltinMSVCAnnotation(Sema &S, CallExpr *TheCall) {
// We need at least one argument.
if (TheCall->getNumArgs() < 1) {
S.Diag(TheCall->getEndLoc(), diag::err_typecheck_call_too_few_args_at_least)
<< 0 << 1 << TheCall->getNumArgs()
<< TheCall->getCallee()->getSourceRange();
return true;
}
// All arguments should be wide string literals.
for (Expr *Arg : TheCall->arguments()) {
auto *Literal = dyn_cast<StringLiteral>(Arg->IgnoreParenCasts());
if (!Literal || !Literal->isWide()) {
S.Diag(Arg->getBeginLoc(), diag::err_msvc_annotation_wide_str)
<< Arg->getSourceRange();
return true;
}
}
return false;
}
/// Check that the argument to __builtin_addressof is a glvalue, and set the
/// result type to the corresponding pointer type.
static bool SemaBuiltinAddressof(Sema &S, CallExpr *TheCall) {
if (checkArgCount(S, TheCall, 1))
return true;
ExprResult Arg(TheCall->getArg(0));
QualType ResultType = S.CheckAddressOfOperand(Arg, TheCall->getBeginLoc());
if (ResultType.isNull())
return true;
TheCall->setArg(0, Arg.get());
TheCall->setType(ResultType);
return false;
}
/// Check the number of arguments and set the result type to
/// the argument type.
static bool SemaBuiltinPreserveAI(Sema &S, CallExpr *TheCall) {
if (checkArgCount(S, TheCall, 1))
return true;
TheCall->setType(TheCall->getArg(0)->getType());
return false;
}
/// Check that the value argument for __builtin_is_aligned(value, alignment) and
/// __builtin_aligned_{up,down}(value, alignment) is an integer or a pointer
/// type (but not a function pointer) and that the alignment is a power-of-two.
static bool SemaBuiltinAlignment(Sema &S, CallExpr *TheCall, unsigned ID) {
if (checkArgCount(S, TheCall, 2))
return true;
clang::Expr *Source = TheCall->getArg(0);
bool IsBooleanAlignBuiltin = ID == Builtin::BI__builtin_is_aligned;
auto IsValidIntegerType = [](QualType Ty) {
return Ty->isIntegerType() && !Ty->isEnumeralType() && !Ty->isBooleanType();
};
QualType SrcTy = Source->getType();
// We should also be able to use it with arrays (but not functions!).
if (SrcTy->canDecayToPointerType() && SrcTy->isArrayType()) {
SrcTy = S.Context.getDecayedType(SrcTy);
}
if ((!SrcTy->isPointerType() && !IsValidIntegerType(SrcTy)) ||
SrcTy->isFunctionPointerType()) {
// FIXME: this is not quite the right error message since we don't allow
// floating point types, or member pointers.
S.Diag(Source->getExprLoc(), diag::err_typecheck_expect_scalar_operand)
<< SrcTy;
return true;
}
clang::Expr *AlignOp = TheCall->getArg(1);
if (!IsValidIntegerType(AlignOp->getType())) {
S.Diag(AlignOp->getExprLoc(), diag::err_typecheck_expect_int)
<< AlignOp->getType();
return true;
}
Expr::EvalResult AlignResult;
unsigned MaxAlignmentBits = S.Context.getIntWidth(SrcTy) - 1;
// We can't check validity of alignment if it is value dependent.
if (!AlignOp->isValueDependent() &&
AlignOp->EvaluateAsInt(AlignResult, S.Context,
Expr::SE_AllowSideEffects)) {
llvm::APSInt AlignValue = AlignResult.Val.getInt();
llvm::APSInt MaxValue(
llvm::APInt::getOneBitSet(MaxAlignmentBits + 1, MaxAlignmentBits));
if (AlignValue < 1) {
S.Diag(AlignOp->getExprLoc(), diag::err_alignment_too_small) << 1;
return true;
}
if (llvm::APSInt::compareValues(AlignValue, MaxValue) > 0) {
S.Diag(AlignOp->getExprLoc(), diag::err_alignment_too_big)
<< toString(MaxValue, 10);
return true;
}
if (!AlignValue.isPowerOf2()) {
S.Diag(AlignOp->getExprLoc(), diag::err_alignment_not_power_of_two);
return true;
}
if (AlignValue == 1) {
S.Diag(AlignOp->getExprLoc(), diag::warn_alignment_builtin_useless)
<< IsBooleanAlignBuiltin;
}
}
ExprResult SrcArg = S.PerformCopyInitialization(
InitializedEntity::InitializeParameter(S.Context, SrcTy, false),
SourceLocation(), Source);
if (SrcArg.isInvalid())
return true;
TheCall->setArg(0, SrcArg.get());
ExprResult AlignArg =
S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
S.Context, AlignOp->getType(), false),
SourceLocation(), AlignOp);
if (AlignArg.isInvalid())
return true;
TheCall->setArg(1, AlignArg.get());
// For align_up/align_down, the return type is the same as the (potentially
// decayed) argument type including qualifiers. For is_aligned(), the result
// is always bool.
TheCall->setType(IsBooleanAlignBuiltin ? S.Context.BoolTy : SrcTy);
return false;
}
static bool SemaBuiltinOverflow(Sema &S, CallExpr *TheCall,
unsigned BuiltinID) {
if (checkArgCount(S, TheCall, 3))
return true;
// First two arguments should be integers.
for (unsigned I = 0; I < 2; ++I) {
ExprResult Arg = S.DefaultFunctionArrayLvalueConversion(TheCall->getArg(I));
if (Arg.isInvalid()) return true;
TheCall->setArg(I, Arg.get());
QualType Ty = Arg.get()->getType();
if (!Ty->isIntegerType()) {
S.Diag(Arg.get()->getBeginLoc(), diag::err_overflow_builtin_must_be_int)
<< Ty << Arg.get()->getSourceRange();
return true;
}
}
// Third argument should be a pointer to a non-const integer.
// IRGen correctly handles volatile, restrict, and address spaces, and
// the other qualifiers aren't possible.
{
ExprResult Arg = S.DefaultFunctionArrayLvalueConversion(TheCall->getArg(2));
if (Arg.isInvalid()) return true;
TheCall->setArg(2, Arg.get());
QualType Ty = Arg.get()->getType();
const auto *PtrTy = Ty->getAs<PointerType>();
if (!PtrTy ||
!PtrTy->getPointeeType()->isIntegerType() ||
PtrTy->getPointeeType().isConstQualified()) {
S.Diag(Arg.get()->getBeginLoc(),
diag::err_overflow_builtin_must_be_ptr_int)
<< Ty << Arg.get()->getSourceRange();
return true;
}
}
// Disallow signed ExtIntType args larger than 128 bits to mul function until
// we improve backend support.
if (BuiltinID == Builtin::BI__builtin_mul_overflow) {
for (unsigned I = 0; I < 3; ++I) {
const auto Arg = TheCall->getArg(I);
// Third argument will be a pointer.
auto Ty = I < 2 ? Arg->getType() : Arg->getType()->getPointeeType();
if (Ty->isExtIntType() && Ty->isSignedIntegerType() &&
S.getASTContext().getIntWidth(Ty) > 128)
return S.Diag(Arg->getBeginLoc(),
diag::err_overflow_builtin_ext_int_max_size)
<< 128;
}
}
return false;
}
static bool SemaBuiltinCallWithStaticChain(Sema &S, CallExpr *BuiltinCall) {
if (checkArgCount(S, BuiltinCall, 2))
return true;
SourceLocation BuiltinLoc = BuiltinCall->getBeginLoc();
Expr *Builtin = BuiltinCall->getCallee()->IgnoreImpCasts();
Expr *Call = BuiltinCall->getArg(0);
Expr *Chain = BuiltinCall->getArg(1);
if (Call->getStmtClass() != Stmt::CallExprClass) {
S.Diag(BuiltinLoc, diag::err_first_argument_to_cwsc_not_call)
<< Call->getSourceRange();
return true;
}
auto CE = cast<CallExpr>(Call);
if (CE->getCallee()->getType()->isBlockPointerType()) {
S.Diag(BuiltinLoc, diag::err_first_argument_to_cwsc_block_call)
<< Call->getSourceRange();
return true;
}
const Decl *TargetDecl = CE->getCalleeDecl();
if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
if (FD->getBuiltinID()) {
S.Diag(BuiltinLoc, diag::err_first_argument_to_cwsc_builtin_call)
<< Call->getSourceRange();
return true;
}
if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens())) {
S.Diag(BuiltinLoc, diag::err_first_argument_to_cwsc_pdtor_call)
<< Call->getSourceRange();
return true;
}
ExprResult ChainResult = S.UsualUnaryConversions(Chain);
if (ChainResult.isInvalid())
return true;
if (!ChainResult.get()->getType()->isPointerType()) {
S.Diag(BuiltinLoc, diag::err_second_argument_to_cwsc_not_pointer)
<< Chain->getSourceRange();
return true;
}
QualType ReturnTy = CE->getCallReturnType(S.Context);
QualType ArgTys[2] = { ReturnTy, ChainResult.get()->getType() };
QualType BuiltinTy = S.Context.getFunctionType(
ReturnTy, ArgTys, FunctionProtoType::ExtProtoInfo());
QualType BuiltinPtrTy = S.Context.getPointerType(BuiltinTy);
Builtin =
S.ImpCastExprToType(Builtin, BuiltinPtrTy, CK_BuiltinFnToFnPtr).get();
BuiltinCall->setType(CE->getType());
BuiltinCall->setValueKind(CE->getValueKind());
BuiltinCall->setObjectKind(CE->getObjectKind());
BuiltinCall->setCallee(Builtin);
BuiltinCall->setArg(1, ChainResult.get());
return false;
}
namespace {
class EstimateSizeFormatHandler
: public analyze_format_string::FormatStringHandler {
size_t Size;
public:
EstimateSizeFormatHandler(StringRef Format)
: Size(std::min(Format.find(0), Format.size()) +
1 /* null byte always written by sprintf */) {}
bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS,
const char *, unsigned SpecifierLen) override {
const size_t FieldWidth = computeFieldWidth(FS);
const size_t Precision = computePrecision(FS);
// The actual format.
switch (FS.getConversionSpecifier().getKind()) {
// Just a char.
case analyze_format_string::ConversionSpecifier::cArg:
case analyze_format_string::ConversionSpecifier::CArg:
Size += std::max(FieldWidth, (size_t)1);
break;
// Just an integer.
case analyze_format_string::ConversionSpecifier::dArg:
case analyze_format_string::ConversionSpecifier::DArg:
case analyze_format_string::ConversionSpecifier::iArg:
case analyze_format_string::ConversionSpecifier::oArg:
case analyze_format_string::ConversionSpecifier::OArg:
case analyze_format_string::ConversionSpecifier::uArg:
case analyze_format_string::ConversionSpecifier::UArg:
case analyze_format_string::ConversionSpecifier::xArg:
case analyze_format_string::ConversionSpecifier::XArg:
Size += std::max(FieldWidth, Precision);
break;
// %g style conversion switches between %f or %e style dynamically.
// %f always takes less space, so default to it.
case analyze_format_string::ConversionSpecifier::gArg:
case analyze_format_string::ConversionSpecifier::GArg:
// Floating point number in the form '[+]ddd.ddd'.
case analyze_format_string::ConversionSpecifier::fArg:
case analyze_format_string::ConversionSpecifier::FArg:
Size += std::max(FieldWidth, 1 /* integer part */ +
(Precision ? 1 + Precision
: 0) /* period + decimal */);
break;
// Floating point number in the form '[-]d.ddde[+-]dd'.
case analyze_format_string::ConversionSpecifier::eArg:
case analyze_format_string::ConversionSpecifier::EArg:
Size +=
std::max(FieldWidth,
1 /* integer part */ +
(Precision ? 1 + Precision : 0) /* period + decimal */ +
1 /* e or E letter */ + 2 /* exponent */);
break;
// Floating point number in the form '[-]0xh.hhhhp±dd'.
case analyze_format_string::ConversionSpecifier::aArg:
case analyze_format_string::ConversionSpecifier::AArg:
Size +=
std::max(FieldWidth,
2 /* 0x */ + 1 /* integer part */ +
(Precision ? 1 + Precision : 0) /* period + decimal */ +
1 /* p or P letter */ + 1 /* + or - */ + 1 /* value */);
break;
// Just a string.
case analyze_format_string::ConversionSpecifier::sArg:
case analyze_format_string::ConversionSpecifier::SArg:
Size += FieldWidth;
break;
// Just a pointer in the form '0xddd'.
case analyze_format_string::ConversionSpecifier::pArg:
Size += std::max(FieldWidth, 2 /* leading 0x */ + Precision);
break;
// A plain percent.
case analyze_format_string::ConversionSpecifier::PercentArg:
Size += 1;
break;
default:
break;
}
Size += FS.hasPlusPrefix() || FS.hasSpacePrefix();
if (FS.hasAlternativeForm()) {
switch (FS.getConversionSpecifier().getKind()) {
default:
break;
// Force a leading '0'.
case analyze_format_string::ConversionSpecifier::oArg:
Size += 1;
break;
// Force a leading '0x'.
case analyze_format_string::ConversionSpecifier::xArg:
case analyze_format_string::ConversionSpecifier::XArg:
Size += 2;
break;
// Force a period '.' before decimal, even if precision is 0.
case analyze_format_string::ConversionSpecifier::aArg:
case analyze_format_string::ConversionSpecifier::AArg:
case analyze_format_string::ConversionSpecifier::eArg:
case analyze_format_string::ConversionSpecifier::EArg:
case analyze_format_string::ConversionSpecifier::fArg:
case analyze_format_string::ConversionSpecifier::FArg:
case analyze_format_string::ConversionSpecifier::gArg:
case analyze_format_string::ConversionSpecifier::GArg:
Size += (Precision ? 0 : 1);
break;
}
}
assert(SpecifierLen <= Size && "no underflow");
Size -= SpecifierLen;
return true;
}
size_t getSizeLowerBound() const { return Size; }
private:
static size_t computeFieldWidth(const analyze_printf::PrintfSpecifier &FS) {
const analyze_format_string::OptionalAmount &FW = FS.getFieldWidth();
size_t FieldWidth = 0;
if (FW.getHowSpecified() == analyze_format_string::OptionalAmount::Constant)
FieldWidth = FW.getConstantAmount();
return FieldWidth;
}
static size_t computePrecision(const analyze_printf::PrintfSpecifier &FS) {
const analyze_format_string::OptionalAmount &FW = FS.getPrecision();
size_t Precision = 0;
// See man 3 printf for default precision value based on the specifier.
switch (FW.getHowSpecified()) {
case analyze_format_string::OptionalAmount::NotSpecified:
switch (FS.getConversionSpecifier().getKind()) {
default:
break;
case analyze_format_string::ConversionSpecifier::dArg: // %d
case analyze_format_string::ConversionSpecifier::DArg: // %D
case analyze_format_string::ConversionSpecifier::iArg: // %i
Precision = 1;
break;
case analyze_format_string::ConversionSpecifier::oArg: // %d
case analyze_format_string::ConversionSpecifier::OArg: // %D
case analyze_format_string::ConversionSpecifier::uArg: // %d
case analyze_format_string::ConversionSpecifier::UArg: // %D
case analyze_format_string::ConversionSpecifier::xArg: // %d
case analyze_format_string::ConversionSpecifier::XArg: // %D
Precision = 1;
break;
case analyze_format_string::ConversionSpecifier::fArg: // %f
case analyze_format_string::ConversionSpecifier::FArg: // %F
case analyze_format_string::ConversionSpecifier::eArg: // %e
case analyze_format_string::ConversionSpecifier::EArg: // %E
case analyze_format_string::ConversionSpecifier::gArg: // %g
case analyze_format_string::ConversionSpecifier::GArg: // %G
Precision = 6;
break;
case analyze_format_string::ConversionSpecifier::pArg: // %d
Precision = 1;
break;
}
break;
case analyze_format_string::OptionalAmount::Constant:
Precision = FW.getConstantAmount();
break;
default:
break;
}
return Precision;
}
};
} // namespace
/// Check a call to BuiltinID for buffer overflows. If BuiltinID is a
/// __builtin_*_chk function, then use the object size argument specified in the
/// source. Otherwise, infer the object size using __builtin_object_size.
void Sema::checkFortifiedBuiltinMemoryFunction(FunctionDecl *FD,
CallExpr *TheCall) {
// FIXME: There are some more useful checks we could be doing here:
// - Evaluate strlen of strcpy arguments, use as object size.
if (TheCall->isValueDependent() || TheCall->isTypeDependent() ||
isConstantEvaluated())
return;
unsigned BuiltinID = FD->getBuiltinID(/*ConsiderWrappers=*/true);
if (!BuiltinID)
return;
const TargetInfo &TI = getASTContext().getTargetInfo();
unsigned SizeTypeWidth = TI.getTypeWidth(TI.getSizeType());
unsigned DiagID = 0;
bool IsChkVariant = false;
Optional<llvm::APSInt> UsedSize;
unsigned SizeIndex, ObjectIndex;
switch (BuiltinID) {
default:
return;
case Builtin::BIsprintf:
case Builtin::BI__builtin___sprintf_chk: {
size_t FormatIndex = BuiltinID == Builtin::BIsprintf ? 1 : 3;
auto *FormatExpr = TheCall->getArg(FormatIndex)->IgnoreParenImpCasts();
if (auto *Format = dyn_cast<StringLiteral>(FormatExpr)) {
if (!Format->isAscii() && !Format->isUTF8())
return;
StringRef FormatStrRef = Format->getString();
EstimateSizeFormatHandler H(FormatStrRef);
const char *FormatBytes = FormatStrRef.data();
const ConstantArrayType *T =
Context.getAsConstantArrayType(Format->getType());
assert(T && "String literal not of constant array type!");
size_t TypeSize = T->getSize().getZExtValue();
// In case there's a null byte somewhere.
size_t StrLen =
std::min(std::max(TypeSize, size_t(1)) - 1, FormatStrRef.find(0));
if (!analyze_format_string::ParsePrintfString(
H, FormatBytes, FormatBytes + StrLen, getLangOpts(),
Context.getTargetInfo(), false)) {
DiagID = diag::warn_fortify_source_format_overflow;
UsedSize = llvm::APSInt::getUnsigned(H.getSizeLowerBound())
.extOrTrunc(SizeTypeWidth);
if (BuiltinID == Builtin::BI__builtin___sprintf_chk) {
IsChkVariant = true;
ObjectIndex = 2;
} else {
IsChkVariant = false;
ObjectIndex = 0;
}
break;
}
}
return;
}
case Builtin::BI__builtin___memcpy_chk:
case Builtin::BI__builtin___memmove_chk:
case Builtin::BI__builtin___memset_chk:
case Builtin::BI__builtin___strlcat_chk:
case Builtin::BI__builtin___strlcpy_chk:
case Builtin::BI__builtin___strncat_chk:
case Builtin::BI__builtin___strncpy_chk:
case Builtin::BI__builtin___stpncpy_chk:
case Builtin::BI__builtin___memccpy_chk:
case Builtin::BI__builtin___mempcpy_chk: {
DiagID = diag::warn_builtin_chk_overflow;
IsChkVariant = true;
SizeIndex = TheCall->getNumArgs() - 2;
ObjectIndex = TheCall->getNumArgs() - 1;
break;
}
case Builtin::BI__builtin___snprintf_chk:
case Builtin::BI__builtin___vsnprintf_chk: {
DiagID = diag::warn_builtin_chk_overflow;
IsChkVariant = true;
SizeIndex = 1;
ObjectIndex = 3;
break;
}
case Builtin::BIstrncat:
case Builtin::BI__builtin_strncat:
case Builtin::BIstrncpy:
case Builtin::BI__builtin_strncpy:
case Builtin::BIstpncpy:
case Builtin::BI__builtin_stpncpy: {
// Whether these functions overflow depends on the runtime strlen of the
// string, not just the buffer size, so emitting the "always overflow"
// diagnostic isn't quite right. We should still diagnose passing a buffer
// size larger than the destination buffer though; this is a runtime abort
// in _FORTIFY_SOURCE mode, and is quite suspicious otherwise.
DiagID = diag::warn_fortify_source_size_mismatch;
SizeIndex = TheCall->getNumArgs() - 1;
ObjectIndex = 0;
break;
}
case Builtin::BImemcpy:
case Builtin::BI__builtin_memcpy:
case Builtin::BImemmove:
case Builtin::BI__builtin_memmove:
case Builtin::BImemset:
case Builtin::BI__builtin_memset:
case Builtin::BImempcpy:
case Builtin::BI__builtin_mempcpy: {
DiagID = diag::warn_fortify_source_overflow;
SizeIndex = TheCall->getNumArgs() - 1;
ObjectIndex = 0;
break;
}
case Builtin::BIsnprintf:
case Builtin::BI__builtin_snprintf:
case Builtin::BIvsnprintf:
case Builtin::BI__builtin_vsnprintf: {
DiagID = diag::warn_fortify_source_size_mismatch;
SizeIndex = 1;
ObjectIndex = 0;
break;
}
}
llvm::APSInt ObjectSize;
// For __builtin___*_chk, the object size is explicitly provided by the caller
// (usually using __builtin_object_size). Use that value to check this call.
if (IsChkVariant) {
Expr::EvalResult Result;
Expr *SizeArg = TheCall->getArg(ObjectIndex);
if (!SizeArg->EvaluateAsInt(Result, getASTContext()))
return;
ObjectSize = Result.Val.getInt();
// Otherwise, try to evaluate an imaginary call to __builtin_object_size.
} else {
// If the parameter has a pass_object_size attribute, then we should use its
// (potentially) more strict checking mode. Otherwise, conservatively assume
// type 0.
int BOSType = 0;
if (const auto *POS =
FD->getParamDecl(ObjectIndex)->getAttr<PassObjectSizeAttr>())
BOSType = POS->getType();
Expr *ObjArg = TheCall->getArg(ObjectIndex);
uint64_t Result;
if (!ObjArg->tryEvaluateObjectSize(Result, getASTContext(), BOSType))
return;
// Get the object size in the target's size_t width.
ObjectSize = llvm::APSInt::getUnsigned(Result).extOrTrunc(SizeTypeWidth);
}
// Evaluate the number of bytes of the object that this call will use.
if (!UsedSize) {
Expr::EvalResult Result;
Expr *UsedSizeArg = TheCall->getArg(SizeIndex);
if (!UsedSizeArg->EvaluateAsInt(Result, getASTContext()))
return;
UsedSize = Result.Val.getInt().extOrTrunc(SizeTypeWidth);
}
if (UsedSize.getValue().ule(ObjectSize))
return;
StringRef FunctionName = getASTContext().BuiltinInfo.getName(BuiltinID);
// Skim off the details of whichever builtin was called to produce a better
// diagnostic, as it's unlikley that the user wrote the __builtin explicitly.
if (IsChkVariant) {
FunctionName = FunctionName.drop_front(std::strlen("__builtin___"));
FunctionName = FunctionName.drop_back(std::strlen("_chk"));
} else if (FunctionName.startswith("__builtin_")) {
FunctionName = FunctionName.drop_front(std::strlen("__builtin_"));
}
DiagRuntimeBehavior(TheCall->getBeginLoc(), TheCall,
PDiag(DiagID)
<< FunctionName << toString(ObjectSize, /*Radix=*/10)
<< toString(UsedSize.getValue(), /*Radix=*/10));
}
static bool SemaBuiltinSEHScopeCheck(Sema &SemaRef, CallExpr *TheCall,
Scope::ScopeFlags NeededScopeFlags,
unsigned DiagID) {
// Scopes aren't available during instantiation. Fortunately, builtin
// functions cannot be template args so they cannot be formed through template
// instantiation. Therefore checking once during the parse is sufficient.
if (SemaRef.inTemplateInstantiation())
return false;
Scope *S = SemaRef.getCurScope();
while (S && !S->isSEHExceptScope())
S = S->getParent();
if (!S || !(S->getFlags() & NeededScopeFlags)) {
auto *DRE = cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
SemaRef.Diag(TheCall->getExprLoc(), DiagID)
<< DRE->getDecl()->getIdentifier();
return true;
}
return false;
}
static inline bool isBlockPointer(Expr *Arg) {
return Arg->getType()->isBlockPointerType();
}
/// OpenCL C v2.0, s6.13.17.2 - Checks that the block parameters are all local
/// void*, which is a requirement of device side enqueue.
static bool checkOpenCLBlockArgs(Sema &S, Expr *BlockArg) {
const BlockPointerType *BPT =
cast<BlockPointerType>(BlockArg->getType().getCanonicalType());
ArrayRef<QualType> Params =
BPT->getPointeeType()->castAs<FunctionProtoType>()->getParamTypes();
unsigned ArgCounter = 0;
bool IllegalParams = false;
// Iterate through the block parameters until either one is found that is not
// a local void*, or the block is valid.
for (ArrayRef<QualType>::iterator I = Params.begin(), E = Params.end();
I != E; ++I, ++ArgCounter) {
if (!(*I)->isPointerType() || !(*I)->getPointeeType()->isVoidType() ||
(*I)->getPointeeType().getQualifiers().getAddressSpace() !=
LangAS::opencl_local) {
// Get the location of the error. If a block literal has been passed
// (BlockExpr) then we can point straight to the offending argument,
// else we just point to the variable reference.
SourceLocation ErrorLoc;
if (isa<BlockExpr>(BlockArg)) {
BlockDecl *BD = cast<BlockExpr>(BlockArg)->getBlockDecl();
ErrorLoc = BD->getParamDecl(ArgCounter)->getBeginLoc();
} else if (isa<DeclRefExpr>(BlockArg)) {
ErrorLoc = cast<DeclRefExpr>(BlockArg)->getBeginLoc();
}
S.Diag(ErrorLoc,
diag::err_opencl_enqueue_kernel_blocks_non_local_void_args);
IllegalParams = true;
}
}
return IllegalParams;
}
static bool checkOpenCLSubgroupExt(Sema &S, CallExpr *Call) {
if (!S.getOpenCLOptions().isSupported("cl_khr_subgroups", S.getLangOpts())) {
S.Diag(Call->getBeginLoc(), diag::err_opencl_requires_extension)
<< 1 << Call->getDirectCallee() << "cl_khr_subgroups";
return true;
}
return false;
}
static bool SemaOpenCLBuiltinNDRangeAndBlock(Sema &S, CallExpr *TheCall) {
if (checkArgCount(S, TheCall, 2))
return true;
if (checkOpenCLSubgroupExt(S, TheCall))
return true;
// First argument is an ndrange_t type.
Expr *NDRangeArg = TheCall->getArg(0);
if (NDRangeArg->getType().getUnqualifiedType().getAsString() != "ndrange_t") {
S.Diag(NDRangeArg->getBeginLoc(), diag::err_opencl_builtin_expected_type)
<< TheCall->getDirectCallee() << "'ndrange_t'";
return true;
}
Expr *BlockArg = TheCall->getArg(1);
if (!isBlockPointer(BlockArg)) {
S.Diag(BlockArg->getBeginLoc(), diag::err_opencl_builtin_expected_type)
<< TheCall->getDirectCallee() << "block";
return true;
}
return checkOpenCLBlockArgs(S, BlockArg);
}
/// OpenCL C v2.0, s6.13.17.6 - Check the argument to the
/// get_kernel_work_group_size
/// and get_kernel_preferred_work_group_size_multiple builtin functions.
static bool SemaOpenCLBuiltinKernelWorkGroupSize(Sema &S, CallExpr *TheCall) {
if (checkArgCount(S, TheCall, 1))
return true;
Expr *BlockArg = TheCall->getArg(0);
if (!isBlockPointer(BlockArg)) {
S.Diag(BlockArg->getBeginLoc(), diag::err_opencl_builtin_expected_type)
<< TheCall->getDirectCallee() << "block";
return true;
}
return checkOpenCLBlockArgs(S, BlockArg);
}
/// Diagnose integer type and any valid implicit conversion to it.
static bool checkOpenCLEnqueueIntType(Sema &S, Expr *E,
const QualType &IntType);
static bool checkOpenCLEnqueueLocalSizeArgs(Sema &S, CallExpr *TheCall,
unsigned Start, unsigned End) {
bool IllegalParams = false;
for (unsigned I = Start; I <= End; ++I)
IllegalParams |= checkOpenCLEnqueueIntType(S, TheCall->getArg(I),
S.Context.getSizeType());
return IllegalParams;
}
/// OpenCL v2.0, s6.13.17.1 - Check that sizes are provided for all
/// 'local void*' parameter of passed block.
static bool checkOpenCLEnqueueVariadicArgs(Sema &S, CallExpr *TheCall,
Expr *BlockArg,
unsigned NumNonVarArgs) {
const BlockPointerType *BPT =
cast<BlockPointerType>(BlockArg->getType().getCanonicalType());
unsigned NumBlockParams =
BPT->getPointeeType()->castAs<FunctionProtoType>()->getNumParams();
unsigned TotalNumArgs = TheCall->getNumArgs();
// For each argument passed to the block, a corresponding uint needs to
// be passed to describe the size of the local memory.
if (TotalNumArgs != NumBlockParams + NumNonVarArgs) {
S.Diag(TheCall->getBeginLoc(),
diag::err_opencl_enqueue_kernel_local_size_args);
return true;
}
// Check that the sizes of the local memory are specified by integers.
return checkOpenCLEnqueueLocalSizeArgs(S, TheCall, NumNonVarArgs,
TotalNumArgs - 1);
}
/// OpenCL C v2.0, s6.13.17 - Enqueue kernel function contains four different
/// overload formats specified in Table 6.13.17.1.
/// int enqueue_kernel(queue_t queue,
/// kernel_enqueue_flags_t flags,
/// const ndrange_t ndrange,
/// void (^block)(void))
/// int enqueue_kernel(queue_t queue,
/// kernel_enqueue_flags_t flags,
/// const ndrange_t ndrange,
/// uint num_events_in_wait_list,
/// clk_event_t *event_wait_list,
/// clk_event_t *event_ret,
/// void (^block)(void))
/// int enqueue_kernel(queue_t queue,
/// kernel_enqueue_flags_t flags,
/// const ndrange_t ndrange,
/// void (^block)(local void*, ...),
/// uint size0, ...)
/// int enqueue_kernel(queue_t queue,
/// kernel_enqueue_flags_t flags,
/// const ndrange_t ndrange,
/// uint num_events_in_wait_list,
/// clk_event_t *event_wait_list,
/// clk_event_t *event_ret,
/// void (^block)(local void*, ...),
/// uint size0, ...)
static bool SemaOpenCLBuiltinEnqueueKernel(Sema &S, CallExpr *TheCall) {
unsigned NumArgs = TheCall->getNumArgs();
if (NumArgs < 4) {
S.Diag(TheCall->getBeginLoc(),
diag::err_typecheck_call_too_few_args_at_least)
<< 0 << 4 << NumArgs;
return true;
}
Expr *Arg0 = TheCall->getArg(0);
Expr *Arg1 = TheCall->getArg(1);
Expr *Arg2 = TheCall->getArg(2);
Expr *Arg3 = TheCall->getArg(3);
// First argument always needs to be a queue_t type.
if (!Arg0->getType()->isQueueT()) {
S.Diag(TheCall->getArg(0)->getBeginLoc(),
diag::err_opencl_builtin_expected_type)
<< TheCall->getDirectCallee() << S.Context.OCLQueueTy;
return true;
}
// Second argument always needs to be a kernel_enqueue_flags_t enum value.
if (!Arg1->getType()->isIntegerType()) {
S.Diag(TheCall->getArg(1)->getBeginLoc(),
diag::err_opencl_builtin_expected_type)
<< TheCall->getDirectCallee() << "'kernel_enqueue_flags_t' (i.e. uint)";
return true;
}
// Third argument is always an ndrange_t type.
if (Arg2->getType().getUnqualifiedType().getAsString() != "ndrange_t") {
S.Diag(TheCall->getArg(2)->getBeginLoc(),
diag::err_opencl_builtin_expected_type)
<< TheCall->getDirectCallee() << "'ndrange_t'";
return true;
}
// With four arguments, there is only one form that the function could be
// called in: no events and no variable arguments.
if (NumArgs == 4) {
// check that the last argument is the right block type.
if (!isBlockPointer(Arg3)) {
S.Diag(Arg3->getBeginLoc(), diag::err_opencl_builtin_expected_type)
<< TheCall->getDirectCallee() << "block";
return true;
}
// we have a block type, check the prototype