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llvm-project/clang/lib/Sema/SemaStmt.cpp

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//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements semantic analysis for statements.
//
//===----------------------------------------------------------------------===//
#include "Sema.h"
#include "clang/AST/APValue.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/StmtObjC.h"
#include "clang/AST/StmtCXX.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
using namespace clang;
Sema::OwningStmtResult Sema::ActOnExprStmt(FullExprArg expr) {
Expr *E = expr->takeAs<Expr>();
assert(E && "ActOnExprStmt(): missing expression");
if (E->getType()->isObjCInterfaceType()) {
if (LangOpts.ObjCNonFragileABI)
Diag(E->getLocEnd(), diag::err_indirection_requires_nonfragile_object)
<< E->getType();
else
Diag(E->getLocEnd(), diag::err_direct_interface_unsupported)
<< E->getType();
return StmtError();
}
// C99 6.8.3p2: The expression in an expression statement is evaluated as a
// void expression for its side effects. Conversion to void allows any
// operand, even incomplete types.
// Same thing in for stmt first clause (when expr) and third clause.
return Owned(static_cast<Stmt*>(E));
}
Sema::OwningStmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) {
return Owned(new (Context) NullStmt(SemiLoc));
}
Sema::OwningStmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg,
SourceLocation StartLoc,
SourceLocation EndLoc) {
DeclGroupRef DG = dg.getAsVal<DeclGroupRef>();
// If we have an invalid decl, just return an error.
if (DG.isNull()) return StmtError();
return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc));
}
void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
const Expr *E = dyn_cast_or_null<Expr>(S);
if (!E)
return;
// Ignore expressions that have void type.
if (E->getType()->isVoidType())
return;
SourceLocation Loc;
SourceRange R1, R2;
if (!E->isUnusedResultAWarning(Loc, R1, R2))
return;
// Okay, we have an unused result. Depending on what the base expression is,
// we might want to make a more specific diagnostic. Check for one of these
// cases now.
unsigned DiagID = diag::warn_unused_expr;
E = E->IgnoreParens();
if (isa<ObjCImplicitSetterGetterRefExpr>(E))
DiagID = diag::warn_unused_property_expr;
Diag(Loc, DiagID) << R1 << R2;
}
Action::OwningStmtResult
Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
MultiStmtArg elts, bool isStmtExpr) {
unsigned NumElts = elts.size();
Stmt **Elts = reinterpret_cast<Stmt**>(elts.release());
// If we're in C89 mode, check that we don't have any decls after stmts. If
// so, emit an extension diagnostic.
if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) {
// Note that __extension__ can be around a decl.
unsigned i = 0;
// Skip over all declarations.
for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i)
/*empty*/;
// We found the end of the list or a statement. Scan for another declstmt.
for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i)
/*empty*/;
if (i != NumElts) {
Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin();
Diag(D->getLocation(), diag::ext_mixed_decls_code);
}
}
// Warn about unused expressions in statements.
for (unsigned i = 0; i != NumElts; ++i) {
// Ignore statements that are last in a statement expression.
if (isStmtExpr && i == NumElts - 1)
continue;
DiagnoseUnusedExprResult(Elts[i]);
}
return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R));
}
Action::OwningStmtResult
Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprArg lhsval,
SourceLocation DotDotDotLoc, ExprArg rhsval,
SourceLocation ColonLoc) {
assert((lhsval.get() != 0) && "missing expression in case statement");
// C99 6.8.4.2p3: The expression shall be an integer constant.
// However, GCC allows any evaluatable integer expression.
Expr *LHSVal = static_cast<Expr*>(lhsval.get());
if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() &&
VerifyIntegerConstantExpression(LHSVal))
return StmtError();
// GCC extension: The expression shall be an integer constant.
Expr *RHSVal = static_cast<Expr*>(rhsval.get());
if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() &&
VerifyIntegerConstantExpression(RHSVal)) {
RHSVal = 0; // Recover by just forgetting about it.
rhsval = 0;
}
if (getSwitchStack().empty()) {
Diag(CaseLoc, diag::err_case_not_in_switch);
return StmtError();
}
// Only now release the smart pointers.
lhsval.release();
rhsval.release();
CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc,
ColonLoc);
getSwitchStack().back()->addSwitchCase(CS);
return Owned(CS);
}
/// ActOnCaseStmtBody - This installs a statement as the body of a case.
void Sema::ActOnCaseStmtBody(StmtTy *caseStmt, StmtArg subStmt) {
CaseStmt *CS = static_cast<CaseStmt*>(caseStmt);
Stmt *SubStmt = subStmt.takeAs<Stmt>();
CS->setSubStmt(SubStmt);
}
Action::OwningStmtResult
Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
StmtArg subStmt, Scope *CurScope) {
Stmt *SubStmt = subStmt.takeAs<Stmt>();
if (getSwitchStack().empty()) {
Diag(DefaultLoc, diag::err_default_not_in_switch);
return Owned(SubStmt);
}
DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt);
getSwitchStack().back()->addSwitchCase(DS);
return Owned(DS);
}
Action::OwningStmtResult
Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II,
SourceLocation ColonLoc, StmtArg subStmt) {
Stmt *SubStmt = subStmt.takeAs<Stmt>();
// Look up the record for this label identifier.
LabelStmt *&LabelDecl = getLabelMap()[II];
// If not forward referenced or defined already, just create a new LabelStmt.
if (LabelDecl == 0)
return Owned(LabelDecl = new (Context) LabelStmt(IdentLoc, II, SubStmt));
assert(LabelDecl->getID() == II && "Label mismatch!");
// Otherwise, this label was either forward reference or multiply defined. If
// multiply defined, reject it now.
if (LabelDecl->getSubStmt()) {
Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID();
Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition);
return Owned(SubStmt);
}
// Otherwise, this label was forward declared, and we just found its real
// definition. Fill in the forward definition and return it.
LabelDecl->setIdentLoc(IdentLoc);
LabelDecl->setSubStmt(SubStmt);
return Owned(LabelDecl);
}
Action::OwningStmtResult
Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal,
StmtArg ThenVal, SourceLocation ElseLoc,
StmtArg ElseVal) {
OwningExprResult CondResult(CondVal.release());
Expr *condExpr = CondResult.takeAs<Expr>();
assert(condExpr && "ActOnIfStmt(): missing expression");
if (!condExpr->isTypeDependent()) {
DefaultFunctionArrayConversion(condExpr);
// Take ownership again until we're past the error checking.
CondResult = condExpr;
QualType condType = condExpr->getType();
if (getLangOptions().CPlusPlus) {
if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4
return StmtError();
} else if (!condType->isScalarType()) // C99 6.8.4.1p1
return StmtError(Diag(IfLoc,
diag::err_typecheck_statement_requires_scalar)
<< condType << condExpr->getSourceRange());
}
Stmt *thenStmt = ThenVal.takeAs<Stmt>();
DiagnoseUnusedExprResult(thenStmt);
// Warn if the if block has a null body without an else value.
// this helps prevent bugs due to typos, such as
// if (condition);
// do_stuff();
if (!ElseVal.get()) {
if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt))
Diag(stmt->getSemiLoc(), diag::warn_empty_if_body);
}
Stmt *elseStmt = ElseVal.takeAs<Stmt>();
DiagnoseUnusedExprResult(elseStmt);
CondResult.release();
return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt,
ElseLoc, elseStmt));
}
Action::OwningStmtResult
Sema::ActOnStartOfSwitchStmt(ExprArg cond) {
Expr *Cond = cond.takeAs<Expr>();
if (getLangOptions().CPlusPlus) {
// C++ 6.4.2.p2:
// The condition shall be of integral type, enumeration type, or of a class
// type for which a single conversion function to integral or enumeration
// type exists (12.3). If the condition is of class type, the condition is
// converted by calling that conversion function, and the result of the
// conversion is used in place of the original condition for the remainder
// of this section. Integral promotions are performed.
if (!Cond->isTypeDependent()) {
QualType Ty = Cond->getType();
// FIXME: Handle class types.
// If the type is wrong a diagnostic will be emitted later at
// ActOnFinishSwitchStmt.
if (Ty->isIntegralType() || Ty->isEnumeralType()) {
// Integral promotions are performed.
// FIXME: Integral promotions for C++ are not complete.
UsualUnaryConversions(Cond);
}
}
} else {
// C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr.
UsualUnaryConversions(Cond);
}
SwitchStmt *SS = new (Context) SwitchStmt(Cond);
getSwitchStack().push_back(SS);
return Owned(SS);
}
/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have
/// the specified width and sign. If an overflow occurs, detect it and emit
/// the specified diagnostic.
void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val,
unsigned NewWidth, bool NewSign,
SourceLocation Loc,
unsigned DiagID) {
// Perform a conversion to the promoted condition type if needed.
if (NewWidth > Val.getBitWidth()) {
// If this is an extension, just do it.
llvm::APSInt OldVal(Val);
Val.extend(NewWidth);
// If the input was signed and negative and the output is unsigned,
// warn.
if (!NewSign && OldVal.isSigned() && OldVal.isNegative())
Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10);
Val.setIsSigned(NewSign);
} else if (NewWidth < Val.getBitWidth()) {
// If this is a truncation, check for overflow.
llvm::APSInt ConvVal(Val);
ConvVal.trunc(NewWidth);
ConvVal.setIsSigned(NewSign);
ConvVal.extend(Val.getBitWidth());
ConvVal.setIsSigned(Val.isSigned());
if (ConvVal != Val)
Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10);
// Regardless of whether a diagnostic was emitted, really do the
// truncation.
Val.trunc(NewWidth);
Val.setIsSigned(NewSign);
} else if (NewSign != Val.isSigned()) {
// Convert the sign to match the sign of the condition. This can cause
// overflow as well: unsigned(INTMIN)
llvm::APSInt OldVal(Val);
Val.setIsSigned(NewSign);
if (Val.isNegative()) // Sign bit changes meaning.
Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10);
}
}
namespace {
struct CaseCompareFunctor {
bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
const llvm::APSInt &RHS) {
return LHS.first < RHS;
}
bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
return LHS.first < RHS.first;
}
bool operator()(const llvm::APSInt &LHS,
const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
return LHS < RHS.first;
}
};
}
/// CmpCaseVals - Comparison predicate for sorting case values.
///
static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs,
const std::pair<llvm::APSInt, CaseStmt*>& rhs) {
if (lhs.first < rhs.first)
return true;
if (lhs.first == rhs.first &&
lhs.second->getCaseLoc().getRawEncoding()
< rhs.second->getCaseLoc().getRawEncoding())
return true;
return false;
}
Action::OwningStmtResult
Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch,
StmtArg Body) {
Stmt *BodyStmt = Body.takeAs<Stmt>();
SwitchStmt *SS = getSwitchStack().back();
assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!");
SS->setBody(BodyStmt, SwitchLoc);
getSwitchStack().pop_back();
Expr *CondExpr = SS->getCond();
QualType CondType = CondExpr->getType();
if (!CondExpr->isTypeDependent() &&
!CondType->isIntegerType()) { // C99 6.8.4.2p1
Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer)
<< CondType << CondExpr->getSourceRange();
return StmtError();
}
// Get the bitwidth of the switched-on value before promotions. We must
// convert the integer case values to this width before comparison.
bool HasDependentValue
= CondExpr->isTypeDependent() || CondExpr->isValueDependent();
unsigned CondWidth
= HasDependentValue? 0
: static_cast<unsigned>(Context.getTypeSize(CondType));
bool CondIsSigned = CondType->isSignedIntegerType();
// Accumulate all of the case values in a vector so that we can sort them
// and detect duplicates. This vector contains the APInt for the case after
// it has been converted to the condition type.
typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy;
CaseValsTy CaseVals;
// Keep track of any GNU case ranges we see. The APSInt is the low value.
std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges;
DefaultStmt *TheDefaultStmt = 0;
bool CaseListIsErroneous = false;
for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue;
SC = SC->getNextSwitchCase()) {
if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) {
if (TheDefaultStmt) {
Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined);
Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev);
// FIXME: Remove the default statement from the switch block so that
// we'll return a valid AST. This requires recursing down the AST and
// finding it, not something we are set up to do right now. For now,
// just lop the entire switch stmt out of the AST.
CaseListIsErroneous = true;
}
TheDefaultStmt = DS;
} else {
CaseStmt *CS = cast<CaseStmt>(SC);
// We already verified that the expression has a i-c-e value (C99
// 6.8.4.2p3) - get that value now.
Expr *Lo = CS->getLHS();
if (Lo->isTypeDependent() || Lo->isValueDependent()) {
HasDependentValue = true;
break;
}
llvm::APSInt LoVal = Lo->EvaluateAsInt(Context);
// Convert the value to the same width/sign as the condition.
ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned,
CS->getLHS()->getLocStart(),
diag::warn_case_value_overflow);
// If the LHS is not the same type as the condition, insert an implicit
// cast.
ImpCastExprToType(Lo, CondType);
CS->setLHS(Lo);
// If this is a case range, remember it in CaseRanges, otherwise CaseVals.
if (CS->getRHS()) {
if (CS->getRHS()->isTypeDependent() ||
CS->getRHS()->isValueDependent()) {
HasDependentValue = true;
break;
}
CaseRanges.push_back(std::make_pair(LoVal, CS));
} else
CaseVals.push_back(std::make_pair(LoVal, CS));
}
}
if (!HasDependentValue) {
// Sort all the scalar case values so we can easily detect duplicates.
std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals);
if (!CaseVals.empty()) {
for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) {
if (CaseVals[i].first == CaseVals[i+1].first) {
// If we have a duplicate, report it.
Diag(CaseVals[i+1].second->getLHS()->getLocStart(),
diag::err_duplicate_case) << CaseVals[i].first.toString(10);
Diag(CaseVals[i].second->getLHS()->getLocStart(),
diag::note_duplicate_case_prev);
// FIXME: We really want to remove the bogus case stmt from the
// substmt, but we have no way to do this right now.
CaseListIsErroneous = true;
}
}
}
// Detect duplicate case ranges, which usually don't exist at all in
// the first place.
if (!CaseRanges.empty()) {
// Sort all the case ranges by their low value so we can easily detect
// overlaps between ranges.
std::stable_sort(CaseRanges.begin(), CaseRanges.end());
// Scan the ranges, computing the high values and removing empty ranges.
std::vector<llvm::APSInt> HiVals;
for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
CaseStmt *CR = CaseRanges[i].second;
Expr *Hi = CR->getRHS();
llvm::APSInt HiVal = Hi->EvaluateAsInt(Context);
// Convert the value to the same width/sign as the condition.
ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned,
CR->getRHS()->getLocStart(),
diag::warn_case_value_overflow);
// If the LHS is not the same type as the condition, insert an implicit
// cast.
ImpCastExprToType(Hi, CondType);
CR->setRHS(Hi);
// If the low value is bigger than the high value, the case is empty.
if (CaseRanges[i].first > HiVal) {
Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range)
<< SourceRange(CR->getLHS()->getLocStart(),
CR->getRHS()->getLocEnd());
CaseRanges.erase(CaseRanges.begin()+i);
--i, --e;
continue;
}
HiVals.push_back(HiVal);
}
// Rescan the ranges, looking for overlap with singleton values and other
// ranges. Since the range list is sorted, we only need to compare case
// ranges with their neighbors.
for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
llvm::APSInt &CRLo = CaseRanges[i].first;
llvm::APSInt &CRHi = HiVals[i];
CaseStmt *CR = CaseRanges[i].second;
// Check to see whether the case range overlaps with any
// singleton cases.
CaseStmt *OverlapStmt = 0;
llvm::APSInt OverlapVal(32);
// Find the smallest value >= the lower bound. If I is in the
// case range, then we have overlap.
CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(),
CaseVals.end(), CRLo,
CaseCompareFunctor());
if (I != CaseVals.end() && I->first < CRHi) {
OverlapVal = I->first; // Found overlap with scalar.
OverlapStmt = I->second;
}
// Find the smallest value bigger than the upper bound.
I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor());
if (I != CaseVals.begin() && (I-1)->first >= CRLo) {
OverlapVal = (I-1)->first; // Found overlap with scalar.
OverlapStmt = (I-1)->second;
}
// Check to see if this case stmt overlaps with the subsequent
// case range.
if (i && CRLo <= HiVals[i-1]) {
OverlapVal = HiVals[i-1]; // Found overlap with range.
OverlapStmt = CaseRanges[i-1].second;
}
if (OverlapStmt) {
// If we have a duplicate, report it.
Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case)
<< OverlapVal.toString(10);
Diag(OverlapStmt->getLHS()->getLocStart(),
diag::note_duplicate_case_prev);
// FIXME: We really want to remove the bogus case stmt from the
// substmt, but we have no way to do this right now.
CaseListIsErroneous = true;
}
}
}
}
// FIXME: If the case list was broken is some way, we don't have a good system
// to patch it up. Instead, just return the whole substmt as broken.
if (CaseListIsErroneous)
return StmtError();
Switch.release();
return Owned(SS);
}
Action::OwningStmtResult
Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, StmtArg Body) {
ExprArg CondArg(Cond.release());
Expr *condExpr = CondArg.takeAs<Expr>();
assert(condExpr && "ActOnWhileStmt(): missing expression");
if (!condExpr->isTypeDependent()) {
DefaultFunctionArrayConversion(condExpr);
CondArg = condExpr;
QualType condType = condExpr->getType();
if (getLangOptions().CPlusPlus) {
if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4
return StmtError();
} else if (!condType->isScalarType()) // C99 6.8.5p2
return StmtError(Diag(WhileLoc,
diag::err_typecheck_statement_requires_scalar)
<< condType << condExpr->getSourceRange());
}
Stmt *bodyStmt = Body.takeAs<Stmt>();
DiagnoseUnusedExprResult(bodyStmt);
CondArg.release();
return Owned(new (Context) WhileStmt(condExpr, bodyStmt, WhileLoc));
}
Action::OwningStmtResult
Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body,
SourceLocation WhileLoc, SourceLocation CondLParen,
ExprArg Cond, SourceLocation CondRParen) {
Expr *condExpr = Cond.takeAs<Expr>();
assert(condExpr && "ActOnDoStmt(): missing expression");
if (!condExpr->isTypeDependent()) {
DefaultFunctionArrayConversion(condExpr);
Cond = condExpr;
QualType condType = condExpr->getType();
if (getLangOptions().CPlusPlus) {
if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4
return StmtError();
} else if (!condType->isScalarType()) // C99 6.8.5p2
return StmtError(Diag(DoLoc,
diag::err_typecheck_statement_requires_scalar)
<< condType << condExpr->getSourceRange());
}
Stmt *bodyStmt = Body.takeAs<Stmt>();
DiagnoseUnusedExprResult(bodyStmt);
Cond.release();
return Owned(new (Context) DoStmt(bodyStmt, condExpr, DoLoc,
WhileLoc, CondRParen));
}
Action::OwningStmtResult
Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
StmtArg first, ExprArg second, ExprArg third,
SourceLocation RParenLoc, StmtArg body) {
Stmt *First = static_cast<Stmt*>(first.get());
Expr *Second = static_cast<Expr*>(second.get());
Expr *Third = static_cast<Expr*>(third.get());
Stmt *Body = static_cast<Stmt*>(body.get());
if (!getLangOptions().CPlusPlus) {
if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) {
// C99 6.8.5p3: The declaration part of a 'for' statement shall only
// declare identifiers for objects having storage class 'auto' or
// 'register'.
for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end();
DI!=DE; ++DI) {
VarDecl *VD = dyn_cast<VarDecl>(*DI);
if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage())
VD = 0;
if (VD == 0)
Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for);
// FIXME: mark decl erroneous!
}
}
}
if (Second && !Second->isTypeDependent()) {
DefaultFunctionArrayConversion(Second);
QualType SecondType = Second->getType();
if (getLangOptions().CPlusPlus) {
if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4
return StmtError();
} else if (!SecondType->isScalarType()) // C99 6.8.5p2
return StmtError(Diag(ForLoc,
diag::err_typecheck_statement_requires_scalar)
<< SecondType << Second->getSourceRange());
}
DiagnoseUnusedExprResult(First);
DiagnoseUnusedExprResult(Third);
DiagnoseUnusedExprResult(Body);
first.release();
second.release();
third.release();
body.release();
return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc,
LParenLoc, RParenLoc));
}
Action::OwningStmtResult
Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc,
SourceLocation LParenLoc,
StmtArg first, ExprArg second,
SourceLocation RParenLoc, StmtArg body) {
Stmt *First = static_cast<Stmt*>(first.get());
Expr *Second = static_cast<Expr*>(second.get());
Stmt *Body = static_cast<Stmt*>(body.get());
if (First) {
QualType FirstType;
if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) {
if (!DS->isSingleDecl())
return StmtError(Diag((*DS->decl_begin())->getLocation(),
diag::err_toomany_element_decls));
Decl *D = DS->getSingleDecl();
FirstType = cast<ValueDecl>(D)->getType();
// C99 6.8.5p3: The declaration part of a 'for' statement shall only
// declare identifiers for objects having storage class 'auto' or
// 'register'.
VarDecl *VD = cast<VarDecl>(D);
if (VD->isBlockVarDecl() && !VD->hasLocalStorage())
return StmtError(Diag(VD->getLocation(),
diag::err_non_variable_decl_in_for));
} else {
if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid)
return StmtError(Diag(First->getLocStart(),
diag::err_selector_element_not_lvalue)
<< First->getSourceRange());
FirstType = static_cast<Expr*>(First)->getType();
}
if (!FirstType->isObjCObjectPointerType() &&
!FirstType->isBlockPointerType())
Diag(ForLoc, diag::err_selector_element_type)
<< FirstType << First->getSourceRange();
}
if (Second) {
DefaultFunctionArrayConversion(Second);
QualType SecondType = Second->getType();
if (!SecondType->isObjCObjectPointerType())
Diag(ForLoc, diag::err_collection_expr_type)
<< SecondType << Second->getSourceRange();
}
first.release();
second.release();
body.release();
return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body,
ForLoc, RParenLoc));
}
Action::OwningStmtResult
Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc,
IdentifierInfo *LabelII) {
// If we are in a block, reject all gotos for now.
if (CurBlock)
return StmtError(Diag(GotoLoc, diag::err_goto_in_block));
// Look up the record for this label identifier.
LabelStmt *&LabelDecl = getLabelMap()[LabelII];
// If we haven't seen this label yet, create a forward reference.
if (LabelDecl == 0)
LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0);
return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc));
}
Action::OwningStmtResult
Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc,
ExprArg DestExp) {
// Convert operand to void*
Expr* E = DestExp.takeAs<Expr>();
if (!E->isTypeDependent()) {
QualType ETy = E->getType();
AssignConvertType ConvTy =
CheckSingleAssignmentConstraints(Context.VoidPtrTy, E);
if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy,
E, "passing"))
return StmtError();
}
return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E));
}
Action::OwningStmtResult
Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) {
Scope *S = CurScope->getContinueParent();
if (!S) {
// C99 6.8.6.2p1: A break shall appear only in or as a loop body.
return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop));
}
return Owned(new (Context) ContinueStmt(ContinueLoc));
}
Action::OwningStmtResult
Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) {
Scope *S = CurScope->getBreakParent();
if (!S) {
// C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body.
return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch));
}
return Owned(new (Context) BreakStmt(BreakLoc));
}
/// ActOnBlockReturnStmt - Utility routine to figure out block's return type.
///
Action::OwningStmtResult
Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
// If this is the first return we've seen in the block, infer the type of
// the block from it.
if (CurBlock->ReturnType.isNull()) {
if (RetValExp) {
// Don't call UsualUnaryConversions(), since we don't want to do
// integer promotions here.
DefaultFunctionArrayConversion(RetValExp);
CurBlock->ReturnType = RetValExp->getType();
if (BlockDeclRefExpr *CDRE = dyn_cast<BlockDeclRefExpr>(RetValExp)) {
// We have to remove a 'const' added to copied-in variable which was
// part of the implementation spec. and not the actual qualifier for
// the variable.
if (CDRE->isConstQualAdded())
CurBlock->ReturnType.removeConst();
}
} else
CurBlock->ReturnType = Context.VoidTy;
}
QualType FnRetType = CurBlock->ReturnType;
if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) {
Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr)
<< getCurFunctionOrMethodDecl()->getDeclName();
return StmtError();
}
// Otherwise, verify that this result type matches the previous one. We are
// pickier with blocks than for normal functions because we don't have GCC
// compatibility to worry about here.
if (CurBlock->ReturnType->isVoidType()) {
if (RetValExp) {
Diag(ReturnLoc, diag::err_return_block_has_expr);
RetValExp->Destroy(Context);
RetValExp = 0;
}
return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
}
if (!RetValExp)
return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr));
if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) {
// we have a non-void block with an expression, continue checking
QualType RetValType = RetValExp->getType();
// C99 6.8.6.4p3(136): The return statement is not an assignment. The
// overlap restriction of subclause 6.5.16.1 does not apply to the case of
// function return.
// In C++ the return statement is handled via a copy initialization.
// the C version of which boils down to CheckSingleAssignmentConstraints.
// FIXME: Leaks RetValExp.
if (PerformCopyInitialization(RetValExp, FnRetType, "returning"))
return StmtError();
if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
}
return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
}
/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that
/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15).
static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType,
Expr *RetExpr) {
QualType ExprType = RetExpr->getType();
// - in a return statement in a function with ...
// ... a class return type ...
if (!RetType->isRecordType())
return false;
// ... the same cv-unqualified type as the function return type ...
if (Ctx.getCanonicalType(RetType).getUnqualifiedType() !=
Ctx.getCanonicalType(ExprType).getUnqualifiedType())
return false;
// ... the expression is the name of a non-volatile automatic object ...
// We ignore parentheses here.
// FIXME: Is this compliant?
const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens());
if (!DR)
return false;
const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
if (!VD)
return false;
return VD->hasLocalStorage() && !VD->getType()->isReferenceType()
&& !VD->getType().isVolatileQualified();
}
Action::OwningStmtResult
Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) {
Expr *RetValExp = rex.takeAs<Expr>();
if (CurBlock)
return ActOnBlockReturnStmt(ReturnLoc, RetValExp);
QualType FnRetType;
if (const FunctionDecl *FD = getCurFunctionDecl()) {
FnRetType = FD->getResultType();
if (FD->hasAttr<NoReturnAttr>())
Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr)
<< getCurFunctionOrMethodDecl()->getDeclName();
} else if (ObjCMethodDecl *MD = getCurMethodDecl())
FnRetType = MD->getResultType();
else // If we don't have a function/method context, bail.
return StmtError();
if (FnRetType->isVoidType()) {
if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns)
unsigned D = diag::ext_return_has_expr;
if (RetValExp->getType()->isVoidType())
D = diag::ext_return_has_void_expr;
// return (some void expression); is legal in C++.
if (D != diag::ext_return_has_void_expr ||
!getLangOptions().CPlusPlus) {
NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
Diag(ReturnLoc, D)
<< CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl)
<< RetValExp->getSourceRange();
}
RetValExp = MaybeCreateCXXExprWithTemporaries(RetValExp, true);
}
return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
}
if (!RetValExp && !FnRetType->isDependentType()) {
unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4
// C99 6.8.6.4p1 (ext_ since GCC warns)
if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr;
if (FunctionDecl *FD = getCurFunctionDecl())
Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/;
else
Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/;
return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0));
}
if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) {
// we have a non-void function with an expression, continue checking
// C99 6.8.6.4p3(136): The return statement is not an assignment. The
// overlap restriction of subclause 6.5.16.1 does not apply to the case of
// function return.
// C++0x 12.8p15: When certain criteria are met, an implementation is
// allowed to omit the copy construction of a class object, [...]
// - in a return statement in a function with a class return type, when
// the expression is the name of a non-volatile automatic object with
// the same cv-unqualified type as the function return type, the copy
// operation can be omitted [...]
// C++0x 12.8p16: When the criteria for elision of a copy operation are met
// and the object to be copied is designated by an lvalue, overload
// resolution to select the constructor for the copy is first performed
// as if the object were designated by an rvalue.
// Note that we only compute Elidable if we're in C++0x, since we don't
// care otherwise.
bool Elidable = getLangOptions().CPlusPlus0x ?
IsReturnCopyElidable(Context, FnRetType, RetValExp) :
false;
// In C++ the return statement is handled via a copy initialization.
// the C version of which boils down to CheckSingleAssignmentConstraints.
// FIXME: Leaks RetValExp on error.
if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable))
return StmtError();
if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
}
if (RetValExp)
RetValExp = MaybeCreateCXXExprWithTemporaries(RetValExp, true);
return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
}
/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently
/// ignore "noop" casts in places where an lvalue is required by an inline asm.
/// We emulate this behavior when -fheinous-gnu-extensions is specified, but
/// provide a strong guidance to not use it.
///
/// This method checks to see if the argument is an acceptable l-value and
/// returns false if it is a case we can handle.
static bool CheckAsmLValue(const Expr *E, Sema &S) {
if (E->isLvalue(S.Context) == Expr::LV_Valid)
return false; // Cool, this is an lvalue.
// Okay, this is not an lvalue, but perhaps it is the result of a cast that we
// are supposed to allow.
const Expr *E2 = E->IgnoreParenNoopCasts(S.Context);
if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) {
if (!S.getLangOptions().HeinousExtensions)
S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue)
<< E->getSourceRange();
else
S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue)
<< E->getSourceRange();
// Accept, even if we emitted an error diagnostic.
return false;
}
// None of the above, just randomly invalid non-lvalue.
return true;
}
Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc,
bool IsSimple,
bool IsVolatile,
unsigned NumOutputs,
unsigned NumInputs,
std::string *Names,
MultiExprArg constraints,
MultiExprArg exprs,
ExprArg asmString,
MultiExprArg clobbers,
SourceLocation RParenLoc) {
unsigned NumClobbers = clobbers.size();
StringLiteral **Constraints =
reinterpret_cast<StringLiteral**>(constraints.get());
Expr **Exprs = reinterpret_cast<Expr **>(exprs.get());
StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get());
StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get());
llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos;
// The parser verifies that there is a string literal here.
if (AsmString->isWide())
return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character)
<< AsmString->getSourceRange());
for (unsigned i = 0; i != NumOutputs; i++) {
StringLiteral *Literal = Constraints[i];
if (Literal->isWide())
return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
<< Literal->getSourceRange());
TargetInfo::ConstraintInfo Info(Literal->getStrData(),
Literal->getByteLength(),
Names[i]);
if (!Context.Target.validateOutputConstraint(Info))
return StmtError(Diag(Literal->getLocStart(),
diag::err_asm_invalid_output_constraint)
<< Info.getConstraintStr());
// Check that the output exprs are valid lvalues.
Expr *OutputExpr = Exprs[i];
if (CheckAsmLValue(OutputExpr, *this)) {
return StmtError(Diag(OutputExpr->getLocStart(),
diag::err_asm_invalid_lvalue_in_output)
<< OutputExpr->getSourceRange());
}
OutputConstraintInfos.push_back(Info);
}
llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) {
StringLiteral *Literal = Constraints[i];
if (Literal->isWide())
return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
<< Literal->getSourceRange());
TargetInfo::ConstraintInfo Info(Literal->getStrData(),
Literal->getByteLength(),
Names[i]);
if (!Context.Target.validateInputConstraint(OutputConstraintInfos.data(),
NumOutputs, Info)) {
return StmtError(Diag(Literal->getLocStart(),
diag::err_asm_invalid_input_constraint)
<< Info.getConstraintStr());
}
Expr *InputExpr = Exprs[i];
// Only allow void types for memory constraints.
if (Info.allowsMemory() && !Info.allowsRegister()) {
if (CheckAsmLValue(InputExpr, *this))
return StmtError(Diag(InputExpr->getLocStart(),
diag::err_asm_invalid_lvalue_in_input)
<< Info.getConstraintStr()
<< InputExpr->getSourceRange());
}
if (Info.allowsRegister()) {
if (InputExpr->getType()->isVoidType()) {
return StmtError(Diag(InputExpr->getLocStart(),
diag::err_asm_invalid_type_in_input)
<< InputExpr->getType() << Info.getConstraintStr()
<< InputExpr->getSourceRange());
}
}
DefaultFunctionArrayConversion(Exprs[i]);
InputConstraintInfos.push_back(Info);
}
// Check that the clobbers are valid.
for (unsigned i = 0; i != NumClobbers; i++) {
StringLiteral *Literal = Clobbers[i];
if (Literal->isWide())
return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
<< Literal->getSourceRange());
std::string Clobber(Literal->getStrData(),
Literal->getStrData() +
Literal->getByteLength());
if (!Context.Target.isValidGCCRegisterName(Clobber.c_str()))
return StmtError(Diag(Literal->getLocStart(),
diag::err_asm_unknown_register_name) << Clobber);
}
constraints.release();
exprs.release();
asmString.release();
clobbers.release();
AsmStmt *NS =
new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs,
Names, Constraints, Exprs, AsmString, NumClobbers,
Clobbers, RParenLoc);
// Validate the asm string, ensuring it makes sense given the operands we
// have.
llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces;
unsigned DiagOffs;
if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) {
Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID)
<< AsmString->getSourceRange();
DeleteStmt(NS);
return StmtError();
}
// Validate tied input operands for type mismatches.
for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) {
TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
// If this is a tied constraint, verify that the output and input have
// either exactly the same type, or that they are int/ptr operands with the
// same size (int/long, int*/long, are ok etc).
if (!Info.hasTiedOperand()) continue;
unsigned TiedTo = Info.getTiedOperand();
Expr *OutputExpr = Exprs[TiedTo];
Expr *InputExpr = Exprs[i+NumOutputs];
QualType InTy = InputExpr->getType();
QualType OutTy = OutputExpr->getType();
if (Context.hasSameType(InTy, OutTy))
continue; // All types can be tied to themselves.
// Int/ptr operands have some special cases that we allow.
if ((OutTy->isIntegerType() || OutTy->isPointerType()) &&
(InTy->isIntegerType() || InTy->isPointerType())) {
// They are ok if they are the same size. Tying void* to int is ok if
// they are the same size, for example. This also allows tying void* to
// int*.
uint64_t OutSize = Context.getTypeSize(OutTy);
uint64_t InSize = Context.getTypeSize(InTy);
if (OutSize == InSize)
continue;
// If the smaller input/output operand is not mentioned in the asm string,
// then we can promote it and the asm string won't notice. Check this
// case now.
bool SmallerValueMentioned = false;
for (unsigned p = 0, e = Pieces.size(); p != e; ++p) {
AsmStmt::AsmStringPiece &Piece = Pieces[p];
if (!Piece.isOperand()) continue;
// If this is a reference to the input and if the input was the smaller
// one, then we have to reject this asm.
if (Piece.getOperandNo() == i+NumOutputs) {
if (InSize < OutSize) {
SmallerValueMentioned = true;
break;
}
}
// If this is a reference to the input and if the input was the smaller
// one, then we have to reject this asm.
if (Piece.getOperandNo() == TiedTo) {
if (InSize > OutSize) {
SmallerValueMentioned = true;
break;
}
}
}
// If the smaller value wasn't mentioned in the asm string, and if the
// output was a register, just extend the shorter one to the size of the
// larger one.
if (!SmallerValueMentioned &&
OutputConstraintInfos[TiedTo].allowsRegister())
continue;
}
Diag(InputExpr->getLocStart(),
diag::err_asm_tying_incompatible_types)
<< InTy << OutTy << OutputExpr->getSourceRange()
<< InputExpr->getSourceRange();
DeleteStmt(NS);
return StmtError();
}
return Owned(NS);
}
Action::OwningStmtResult
Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
SourceLocation RParen, DeclPtrTy Parm,
StmtArg Body, StmtArg catchList) {
Stmt *CatchList = catchList.takeAs<Stmt>();
ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>());
// PVD == 0 implies @catch(...).
if (PVD) {
// If we already know the decl is invalid, reject it.
if (PVD->isInvalidDecl())
return StmtError();
if (!PVD->getType()->isObjCObjectPointerType())
return StmtError(Diag(PVD->getLocation(),
diag::err_catch_param_not_objc_type));
if (PVD->getType()->isObjCQualifiedIdType())
return StmtError(Diag(PVD->getLocation(),
diag::err_illegal_qualifiers_on_catch_parm));
}
ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen,
PVD, Body.takeAs<Stmt>(), CatchList);
return Owned(CatchList ? CatchList : CS);
}
Action::OwningStmtResult
Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) {
return Owned(new (Context) ObjCAtFinallyStmt(AtLoc,
static_cast<Stmt*>(Body.release())));
}
Action::OwningStmtResult
Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc,
StmtArg Try, StmtArg Catch, StmtArg Finally) {
CurFunctionNeedsScopeChecking = true;
return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(),
Catch.takeAs<Stmt>(),
Finally.takeAs<Stmt>()));
}
Action::OwningStmtResult
Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) {
Expr *ThrowExpr = expr.takeAs<Expr>();
if (!ThrowExpr) {
// @throw without an expression designates a rethrow (which much occur
// in the context of an @catch clause).
Scope *AtCatchParent = CurScope;
while (AtCatchParent && !AtCatchParent->isAtCatchScope())
AtCatchParent = AtCatchParent->getParent();
if (!AtCatchParent)
return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch));
} else {
QualType ThrowType = ThrowExpr->getType();
// Make sure the expression type is an ObjC pointer or "void *".
if (!ThrowType->isObjCObjectPointerType()) {
const PointerType *PT = ThrowType->getAs<PointerType>();
if (!PT || !PT->getPointeeType()->isVoidType())
return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object)
<< ThrowExpr->getType() << ThrowExpr->getSourceRange());
}
}
return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr));
}
Action::OwningStmtResult
Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr,
StmtArg SynchBody) {
CurFunctionNeedsScopeChecking = true;
// Make sure the expression type is an ObjC pointer or "void *".
Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get());
if (!SyncExpr->getType()->isObjCObjectPointerType()) {
const PointerType *PT = SyncExpr->getType()->getAs<PointerType>();
if (!PT || !PT->getPointeeType()->isVoidType())
return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object)
<< SyncExpr->getType() << SyncExpr->getSourceRange());
}
return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc,
SynchExpr.takeAs<Stmt>(),
SynchBody.takeAs<Stmt>()));
}
/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block
/// and creates a proper catch handler from them.
Action::OwningStmtResult
Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl,
StmtArg HandlerBlock) {
// There's nothing to test that ActOnExceptionDecl didn't already test.
return Owned(new (Context) CXXCatchStmt(CatchLoc,
cast_or_null<VarDecl>(ExDecl.getAs<Decl>()),
HandlerBlock.takeAs<Stmt>()));
}
class TypeWithHandler {
QualType t;
CXXCatchStmt *stmt;
public:
TypeWithHandler(const QualType &type, CXXCatchStmt *statement)
: t(type), stmt(statement) {}
bool operator<(const TypeWithHandler &y) const {
if (t.getTypePtr() < y.t.getTypePtr())
return true;
else if (t.getTypePtr() > y.t.getTypePtr())
return false;
else if (t.getCVRQualifiers() < y.t.getCVRQualifiers())
return true;
else if (t.getCVRQualifiers() < y.t.getCVRQualifiers())
return false;
else
return getTypeSpecStartLoc() < y.getTypeSpecStartLoc();
}
bool operator==(const TypeWithHandler& other) const {
return t.getTypePtr() == other.t.getTypePtr()
&& t.getCVRQualifiers() == other.t.getCVRQualifiers();
}
QualType getQualType() const { return t; }
CXXCatchStmt *getCatchStmt() const { return stmt; }
SourceLocation getTypeSpecStartLoc() const {
return stmt->getExceptionDecl()->getTypeSpecStartLoc();
}
};
/// ActOnCXXTryBlock - Takes a try compound-statement and a number of
/// handlers and creates a try statement from them.
Action::OwningStmtResult
Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock,
MultiStmtArg RawHandlers) {
unsigned NumHandlers = RawHandlers.size();
assert(NumHandlers > 0 &&
"The parser shouldn't call this if there are no handlers.");
Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get());
llvm::SmallVector<TypeWithHandler, 8> TypesWithHandlers;
for(unsigned i = 0; i < NumHandlers; ++i) {
CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]);
if (!Handler->getExceptionDecl()) {
if (i < NumHandlers - 1)
return StmtError(Diag(Handler->getLocStart(),
diag::err_early_catch_all));
continue;
}
const QualType CaughtType = Handler->getCaughtType();
const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType);
TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler));
}
// Detect handlers for the same type as an earlier one.
if (NumHandlers > 1) {
llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end());
TypeWithHandler prev = TypesWithHandlers[0];
for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) {
TypeWithHandler curr = TypesWithHandlers[i];
if (curr == prev) {
Diag(curr.getTypeSpecStartLoc(),
diag::warn_exception_caught_by_earlier_handler)
<< curr.getCatchStmt()->getCaughtType().getAsString();
Diag(prev.getTypeSpecStartLoc(),
diag::note_previous_exception_handler)
<< prev.getCatchStmt()->getCaughtType().getAsString();
}
prev = curr;
}
}
// FIXME: We should detect handlers that cannot catch anything because an
// earlier handler catches a superclass. Need to find a method that is not
// quadratic for this.
// Neither of these are explicitly forbidden, but every compiler detects them
// and warns.
CurFunctionNeedsScopeChecking = true;
RawHandlers.release();
return Owned(new (Context) CXXTryStmt(TryLoc,
static_cast<Stmt*>(TryBlock.release()),
Handlers, NumHandlers));
}
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