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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/Expr.h"
#include "clang/AST/ASTContext.h"
#include "clang/Basic/TargetInfo.h"
using namespace clang;
Sema::OwningStmtResult Sema::ActOnExprStmt(ExprArg expr) {
Expr *E = static_cast<Expr*>(expr.release());
assert(E && "ActOnExprStmt(): missing expression");
// 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(DeclTy *decl,
SourceLocation StartLoc,
SourceLocation EndLoc) {
if (decl == 0)
return StmtError();
Decl *D = static_cast<Decl *>(decl);
// This is a temporary hack until we are always passing around
// DeclGroupRefs.
llvm::SmallVector<Decl*, 10> decls;
while (D) {
Decl* d = D;
D = D->getNextDeclarator();
d->setNextDeclarator(0);
decls.push_back(d);
}
assert (!decls.empty());
if (decls.size() == 1) {
DeclGroupRef DG(*decls.begin());
return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc));
}
else {
DeclGroupRef DG(DeclGroup::Create(Context, decls.size(), &decls[0]));
return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc));
}
}
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) {
Expr *E = dyn_cast<Expr>(Elts[i]);
if (!E) continue;
// Warn about expressions with unused results if they are non-void and if
// this not the last stmt in a stmt expr.
if (E->getType()->isVoidType() || (isStmtExpr && i == NumElts-1))
continue;
SourceLocation Loc;
SourceRange R1, R2;
if (!E->isUnusedResultAWarning(Loc, R1, R2))
continue;
Diag(Loc, diag::warn_unused_expr) << R1 << R2;
}
return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R));
}
Action::OwningStmtResult
Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprArg lhsval,
SourceLocation DotDotDotLoc, ExprArg rhsval,
SourceLocation ColonLoc, StmtArg subStmt) {
Stmt *SubStmt = static_cast<Stmt*>(subStmt.release());
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 (VerifyIntegerConstantExpression(LHSVal))
return Owned(SubStmt);
// GCC extension: The expression shall be an integer constant.
Expr *RHSVal = static_cast<Expr*>(rhsval.get());
if (RHSVal && VerifyIntegerConstantExpression(RHSVal)) {
RHSVal = 0; // Recover by just forgetting about it.
rhsval = 0;
}
if (SwitchStack.empty()) {
Diag(CaseLoc, diag::err_case_not_in_switch);
return Owned(SubStmt);
}
// Only now release the smart pointers.
lhsval.release();
rhsval.release();
CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, SubStmt, CaseLoc);
SwitchStack.back()->addSwitchCase(CS);
return Owned(CS);
}
Action::OwningStmtResult
Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
StmtArg subStmt, Scope *CurScope) {
Stmt *SubStmt = static_cast<Stmt*>(subStmt.release());
if (SwitchStack.empty()) {
Diag(DefaultLoc, diag::err_default_not_in_switch);
return Owned(SubStmt);
}
DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, SubStmt);
SwitchStack.back()->addSwitchCase(DS);
return Owned(DS);
}
Action::OwningStmtResult
Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II,
SourceLocation ColonLoc, StmtArg subStmt) {
Stmt *SubStmt = static_cast<Stmt*>(subStmt.release());
// Look up the record for this label identifier.
LabelStmt *&LabelDecl = LabelMap[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, ExprArg CondVal,
StmtArg ThenVal, SourceLocation ElseLoc,
StmtArg ElseVal) {
Expr *condExpr = (Expr *)CondVal.release();
assert(condExpr && "ActOnIfStmt(): missing expression");
DefaultFunctionArrayConversion(condExpr);
// Take ownership again until we're past the error checking.
CondVal = 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 = (Stmt *)ThenVal.release();
// 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);
}
CondVal.release();
return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt,
(Stmt*)ElseVal.release()));
}
Action::OwningStmtResult
Sema::ActOnStartOfSwitchStmt(ExprArg cond) {
Expr *Cond = static_cast<Expr*>(cond.release());
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.
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);
SwitchStack.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 = (Stmt*)Body.release();
SwitchStmt *SS = SwitchStack.back();
assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!");
SS->setBody(BodyStmt, SwitchLoc);
SwitchStack.pop_back();
Expr *CondExpr = SS->getCond();
QualType CondType = CondExpr->getType();
if (!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.
unsigned CondWidth = 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;
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();
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())
CaseRanges.push_back(std::make_pair(LoVal, CS));
else
CaseVals.push_back(std::make_pair(LoVal, CS));
}
}
// 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, ExprArg Cond, StmtArg Body) {
Expr *condExpr = (Expr *)Cond.release();
assert(condExpr && "ActOnWhileStmt(): missing expression");
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(WhileLoc,
diag::err_typecheck_statement_requires_scalar)
<< condType << condExpr->getSourceRange());
Cond.release();
return Owned(new (Context) WhileStmt(condExpr, (Stmt*)Body.release(),
WhileLoc));
}
Action::OwningStmtResult
Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body,
SourceLocation WhileLoc, ExprArg Cond) {
Expr *condExpr = (Expr *)Cond.release();
assert(condExpr && "ActOnDoStmt(): missing expression");
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());
Cond.release();
return Owned(new (Context) DoStmt((Stmt*)Body.release(), condExpr, DoLoc));
}
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) {
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());
}
first.release();
second.release();
third.release();
body.release();
return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc));
}
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->hasSolitaryDecl())
return StmtError(Diag((*DS->decl_begin())->getLocation(),
diag::err_toomany_element_decls));
Decl *D = DS->getSolitaryDecl();
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 {
Expr::isLvalueResult lval = cast<Expr>(First)->isLvalue(Context);
if (lval != Expr::LV_Valid)
return StmtError(Diag(First->getLocStart(),
diag::err_selector_element_not_lvalue)
<< First->getSourceRange());
FirstType = static_cast<Expr*>(First)->getType();
}
if (!Context.isObjCObjectPointerType(FirstType))
Diag(ForLoc, diag::err_selector_element_type)
<< FirstType << First->getSourceRange();
}
if (Second) {
DefaultFunctionArrayConversion(Second);
QualType SecondType = Second->getType();
if (!Context.isObjCObjectPointerType(SecondType))
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 = LabelMap[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) {
// FIXME: Verify that the operand is convertible to void*.
return Owned(new (Context) IndirectGotoStmt((Expr*)DestExp.release()));
}
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 == 0) {
if (RetValExp) {
// Don't call UsualUnaryConversions(), since we don't want to do
// integer promotions here.
DefaultFunctionArrayConversion(RetValExp);
CurBlock->ReturnType = RetValExp->getType().getTypePtr();
} else
CurBlock->ReturnType = Context.VoidTy.getTypePtr();
}
QualType FnRetType = QualType(CurBlock->ReturnType, 0);
// 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));
}
Action::OwningStmtResult
Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) {
Expr *RetValExp = static_cast<Expr *>(rex.release());
if (CurBlock)
return ActOnBlockReturnStmt(ReturnLoc, RetValExp);
QualType FnRetType;
if (FunctionDecl *FD = getCurFunctionDecl())
FnRetType = FD->getResultType();
else
FnRetType = getCurMethodDecl()->getResultType();
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();
}
}
return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
}
if (!RetValExp) {
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
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));
}
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());
std::string OutputConstraint(Literal->getStrData(),
Literal->getByteLength());
TargetInfo::ConstraintInfo info;
if (!Context.Target.validateOutputConstraint(OutputConstraint.c_str(),info))
return StmtError(Diag(Literal->getLocStart(),
diag::err_asm_invalid_output_constraint) << OutputConstraint);
// Check that the output exprs are valid lvalues.
ParenExpr *OutputExpr = cast<ParenExpr>(Exprs[i]);
Expr::isLvalueResult Result = OutputExpr->isLvalue(Context);
if (Result != Expr::LV_Valid) {
return StmtError(Diag(OutputExpr->getSubExpr()->getLocStart(),
diag::err_asm_invalid_lvalue_in_output)
<< OutputExpr->getSubExpr()->getSourceRange());
}
OutputConstraintInfos.push_back(info);
}
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());
std::string InputConstraint(Literal->getStrData(),
Literal->getByteLength());
TargetInfo::ConstraintInfo info;
if (!Context.Target.validateInputConstraint(InputConstraint.c_str(),
&Names[0],
&Names[0] + NumOutputs,
&OutputConstraintInfos[0],
info)) {
return StmtError(Diag(Literal->getLocStart(),
diag::err_asm_invalid_input_constraint) << InputConstraint);
}
ParenExpr *InputExpr = cast<ParenExpr>(Exprs[i]);
// Only allow void types for memory constraints.
if ((info & TargetInfo::CI_AllowsMemory)
&& !(info & TargetInfo::CI_AllowsRegister)) {
if (InputExpr->isLvalue(Context) != Expr::LV_Valid)
return StmtError(Diag(InputExpr->getSubExpr()->getLocStart(),
diag::err_asm_invalid_lvalue_in_input)
<< InputConstraint << InputExpr->getSubExpr()->getSourceRange());
}
if (info & TargetInfo::CI_AllowsRegister) {
if (InputExpr->getType()->isVoidType()) {
return StmtError(Diag(InputExpr->getSubExpr()->getLocStart(),
diag::err_asm_invalid_type_in_input)
<< InputExpr->getType() << InputConstraint
<< InputExpr->getSubExpr()->getSourceRange());
}
DefaultFunctionArrayConversion(Exprs[i]);
}
}
// 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());
llvm::SmallString<16> 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.c_str());
}
constraints.release();
exprs.release();
asmString.release();
clobbers.release();
return Owned(new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs,
NumInputs, Names, Constraints, Exprs,
AsmString, NumClobbers,
Clobbers, RParenLoc));
}
Action::OwningStmtResult
Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
SourceLocation RParen, StmtArg Parm,
StmtArg Body, StmtArg catchList) {
Stmt *CatchList = static_cast<Stmt*>(catchList.release());
ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen,
static_cast<Stmt*>(Parm.release()), static_cast<Stmt*>(Body.release()),
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) {
return Owned(new (Context) ObjCAtTryStmt(AtLoc,
static_cast<Stmt*>(Try.release()),
static_cast<Stmt*>(Catch.release()),
static_cast<Stmt*>(Finally.release())));
}
Action::OwningStmtResult
Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) {
Expr *ThrowExpr = static_cast<Expr*>(expr.release());
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 (!Context.isObjCObjectPointerType(ThrowType)) {
const PointerType *PT = ThrowType->getAsPointerType();
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) {
return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc,
static_cast<Stmt*>(SynchExpr.release()),
static_cast<Stmt*>(SynchBody.release())));
}
/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block
/// and creates a proper catch handler from them.
Action::OwningStmtResult
Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclTy *ExDecl,
StmtArg HandlerBlock) {
// There's nothing to test that ActOnExceptionDecl didn't already test.
return Owned(new (Context) CXXCatchStmt(CatchLoc,
static_cast<VarDecl*>(ExDecl),
static_cast<Stmt*>(HandlerBlock.release())));
}
/// 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());
for(unsigned i = 0; i < NumHandlers - 1; ++i) {
CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]);
if (!Handler->getExceptionDecl())
return StmtError(Diag(Handler->getLocStart(), diag::err_early_catch_all));
}
// FIXME: We should detect handlers for the same type as an earlier one.
// This one is rather easy.
// 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.
RawHandlers.release();
return Owned(new (Context) CXXTryStmt(TryLoc,
static_cast<Stmt*>(TryBlock.release()),
Handlers, NumHandlers));
}
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