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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/Basic/TargetInfo.h"
#include "clang/Basic/Diagnostic.h"
using namespace clang;
Sema::StmtResult Sema::ActOnExprStmt(ExprTy *expr) {
Expr *E = static_cast<Expr*>(expr);
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 E;
}
Sema::StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) {
return new NullStmt(SemiLoc);
}
Sema::StmtResult Sema::ActOnDeclStmt(DeclTy *decl, SourceLocation StartLoc,
SourceLocation EndLoc) {
if (decl == 0)
return true;
ScopedDecl *SD = cast<ScopedDecl>(static_cast<Decl *>(decl));
// This is a temporary hack until we are always passing around
// DeclGroupRefs.
llvm::SmallVector<Decl*, 10> decls;
while (SD) {
ScopedDecl* d = SD;
SD = SD->getNextDeclarator();
d->setNextDeclarator(0);
decls.push_back(d);
}
assert (!decls.empty());
if (decls.size() == 1) {
DeclGroupOwningRef DG(*decls.begin());
return new DeclStmt(DG, StartLoc, EndLoc);
}
else {
DeclGroupOwningRef DG(DeclGroup::Create(Context, decls.size(), &decls[0]));
return new DeclStmt(DG, StartLoc, EndLoc);
}
}
Action::StmtResult
Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
StmtTy **elts, unsigned NumElts, bool isStmtExpr) {
Stmt **Elts = reinterpret_cast<Stmt**>(elts);
// 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) {
ScopedDecl *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 (E->hasLocalSideEffect() || E->getType()->isVoidType())
continue;
// The last expr in a stmt expr really is used.
if (isStmtExpr && i == NumElts-1)
continue;
/// DiagnoseDeadExpr - This expression is side-effect free and evaluated in
/// a context where the result is unused. Emit a diagnostic to warn about
/// this.
if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E))
Diag(BO->getOperatorLoc(), diag::warn_unused_expr)
<< BO->getLHS()->getSourceRange() << BO->getRHS()->getSourceRange();
else if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E))
Diag(UO->getOperatorLoc(), diag::warn_unused_expr)
<< UO->getSubExpr()->getSourceRange();
else
Diag(E->getExprLoc(), diag::warn_unused_expr) << E->getSourceRange();
}
return new CompoundStmt(Elts, NumElts, L, R);
}
Action::StmtResult
Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprTy *lhsval,
SourceLocation DotDotDotLoc, ExprTy *rhsval,
SourceLocation ColonLoc, StmtTy *subStmt) {
Stmt *SubStmt = static_cast<Stmt*>(subStmt);
Expr *LHSVal = ((Expr *)lhsval), *RHSVal = ((Expr *)rhsval);
assert((LHSVal != 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.
if (VerifyIntegerConstantExpression(LHSVal))
return SubStmt;
// GCC extension: The expression shall be an integer constant.
if (RHSVal && VerifyIntegerConstantExpression(RHSVal))
RHSVal = 0; // Recover by just forgetting about it.
if (SwitchStack.empty()) {
Diag(CaseLoc, diag::err_case_not_in_switch);
return SubStmt;
}
CaseStmt *CS = new CaseStmt(LHSVal, RHSVal, SubStmt, CaseLoc);
SwitchStack.back()->addSwitchCase(CS);
return CS;
}
Action::StmtResult
Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
StmtTy *subStmt, Scope *CurScope) {
Stmt *SubStmt = static_cast<Stmt*>(subStmt);
if (SwitchStack.empty()) {
Diag(DefaultLoc, diag::err_default_not_in_switch);
return SubStmt;
}
DefaultStmt *DS = new DefaultStmt(DefaultLoc, SubStmt);
SwitchStack.back()->addSwitchCase(DS);
return DS;
}
Action::StmtResult
Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II,
SourceLocation ColonLoc, StmtTy *subStmt) {
Stmt *SubStmt = static_cast<Stmt*>(subStmt);
// 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 LabelDecl = new 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 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 LabelDecl;
}
Action::StmtResult
Sema::ActOnIfStmt(SourceLocation IfLoc, ExprTy *CondVal,
StmtTy *ThenVal, SourceLocation ElseLoc,
StmtTy *ElseVal) {
Expr *condExpr = (Expr *)CondVal;
Stmt *thenStmt = (Stmt *)ThenVal;
assert(condExpr && "ActOnIfStmt(): missing expression");
DefaultFunctionArrayConversion(condExpr);
QualType condType = condExpr->getType();
if (getLangOptions().CPlusPlus) {
if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4
return true;
} else if (!condType->isScalarType()) // C99 6.8.4.1p1
return Diag(IfLoc, diag::err_typecheck_statement_requires_scalar)
<< condType << condExpr->getSourceRange();
// 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) {
if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt))
Diag(stmt->getSemiLoc(), diag::warn_empty_if_body);
}
return new IfStmt(IfLoc, condExpr, thenStmt, (Stmt*)ElseVal);
}
Action::StmtResult
Sema::ActOnStartOfSwitchStmt(ExprTy *cond) {
Expr *Cond = static_cast<Expr*>(cond);
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 SwitchStmt(Cond);
SwitchStack.push_back(SS);
return 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::StmtResult
Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtTy *Switch,
ExprTy *Body) {
Stmt *BodyStmt = (Stmt*)Body;
SwitchStmt *SS = SwitchStack.back();
assert(SS == (SwitchStmt*)Switch && "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 true;
}
// 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 true;
return SS;
}
Action::StmtResult
Sema::ActOnWhileStmt(SourceLocation WhileLoc, ExprTy *Cond, StmtTy *Body) {
Expr *condExpr = (Expr *)Cond;
assert(condExpr && "ActOnWhileStmt(): missing expression");
DefaultFunctionArrayConversion(condExpr);
QualType condType = condExpr->getType();
if (getLangOptions().CPlusPlus) {
if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4
return true;
} else if (!condType->isScalarType()) // C99 6.8.5p2
return Diag(WhileLoc, diag::err_typecheck_statement_requires_scalar)
<< condType << condExpr->getSourceRange();
return new WhileStmt(condExpr, (Stmt*)Body, WhileLoc);
}
Action::StmtResult
Sema::ActOnDoStmt(SourceLocation DoLoc, StmtTy *Body,
SourceLocation WhileLoc, ExprTy *Cond) {
Expr *condExpr = (Expr *)Cond;
assert(condExpr && "ActOnDoStmt(): missing expression");
DefaultFunctionArrayConversion(condExpr);
QualType condType = condExpr->getType();
if (getLangOptions().CPlusPlus) {
if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4
return true;
} else if (!condType->isScalarType()) // C99 6.8.5p2
return Diag(DoLoc, diag::err_typecheck_statement_requires_scalar)
<< condType << condExpr->getSourceRange();
return new DoStmt((Stmt*)Body, condExpr, DoLoc);
}
Action::StmtResult
Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
StmtTy *first, ExprTy *second, ExprTy *third,
SourceLocation RParenLoc, StmtTy *body) {
Stmt *First = static_cast<Stmt*>(first);
Expr *Second = static_cast<Expr*>(second);
Expr *Third = static_cast<Expr*>(third);
Stmt *Body = static_cast<Stmt*>(body);
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 true;
} else if (!SecondType->isScalarType()) // C99 6.8.5p2
return Diag(ForLoc, diag::err_typecheck_statement_requires_scalar)
<< SecondType << Second->getSourceRange();
}
return new ForStmt(First, Second, Third, Body, ForLoc);
}
Action::StmtResult
Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc,
SourceLocation LParenLoc,
StmtTy *first, ExprTy *second,
SourceLocation RParenLoc, StmtTy *body) {
Stmt *First = static_cast<Stmt*>(first);
Expr *Second = static_cast<Expr*>(second);
Stmt *Body = static_cast<Stmt*>(body);
if (First) {
QualType FirstType;
if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) {
if (!DS->hasSolitaryDecl())
return Diag((*DS->decl_begin())->getLocation(),
diag::err_toomany_element_decls);
ScopedDecl *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 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 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();
}
return new ObjCForCollectionStmt(First, Second, Body, ForLoc, RParenLoc);
}
Action::StmtResult
Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc,
IdentifierInfo *LabelII) {
// If we are in a block, reject all gotos for now.
if (CurBlock)
return 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 LabelStmt(LabelLoc, LabelII, 0);
return new GotoStmt(LabelDecl, GotoLoc, LabelLoc);
}
Action::StmtResult
Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc,SourceLocation StarLoc,
ExprTy *DestExp) {
// FIXME: Verify that the operand is convertible to void*.
return new IndirectGotoStmt((Expr*)DestExp);
}
Action::StmtResult
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.
Diag(ContinueLoc, diag::err_continue_not_in_loop);
return true;
}
return new ContinueStmt(ContinueLoc);
}
Action::StmtResult
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.
Diag(BreakLoc, diag::err_break_not_in_loop_or_switch);
return true;
}
return new BreakStmt(BreakLoc);
}
/// ActOnBlockReturnStmt - Utility routine to figure out block's return type.
///
Action::StmtResult
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();
return new ReturnStmt(ReturnLoc, RetValExp);
}
// 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);
delete RetValExp;
RetValExp = 0;
}
return new ReturnStmt(ReturnLoc, RetValExp);
}
if (!RetValExp) {
Diag(ReturnLoc, diag::err_block_return_missing_expr);
return true;
}
// we have a non-void block with an expression, continue checking
QualType RetValType = RetValExp->getType();
// For now, restrict multiple return statements in a block to have
// strict compatible types only.
QualType BlockQT = QualType(CurBlock->ReturnType, 0);
if (Context.getCanonicalType(BlockQT).getTypePtr()
!= Context.getCanonicalType(RetValType).getTypePtr()) {
DiagnoseAssignmentResult(Incompatible, ReturnLoc, BlockQT,
RetValType, RetValExp, "returning");
return true;
}
if (RetValExp) CheckReturnStackAddr(RetValExp, BlockQT, ReturnLoc);
return new ReturnStmt(ReturnLoc, (Expr*)RetValExp);
}
Action::StmtResult
Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprTy *rex) {
Expr *RetValExp = static_cast<Expr *>(rex);
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 new 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 new 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.
if (PerformCopyInitialization(RetValExp, FnRetType, "returning"))
return true;
if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
}
return new ReturnStmt(ReturnLoc, (Expr*)RetValExp);
}
Sema::StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc,
bool IsSimple,
bool IsVolatile,
unsigned NumOutputs,
unsigned NumInputs,
std::string *Names,
ExprTy **constraints,
ExprTy **exprs,
ExprTy *asmString,
unsigned NumClobbers,
ExprTy **clobbers,
SourceLocation RParenLoc) {
StringLiteral **Constraints = reinterpret_cast<StringLiteral**>(constraints);
Expr **Exprs = reinterpret_cast<Expr **>(exprs);
StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString);
StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers);
// The parser verifies that there is a string literal here.
if (AsmString->isWide())
// FIXME: We currently leak memory here.
return Diag(AsmString->getLocStart(), diag::err_asm_wide_character)
<< AsmString->getSourceRange();
for (unsigned i = 0; i != NumOutputs; i++) {
StringLiteral *Literal = Constraints[i];
if (Literal->isWide())
// FIXME: We currently leak memory here.
return 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))
// FIXME: We currently leak memory here.
return 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) {
// FIXME: We currently leak memory here.
return Diag(OutputExpr->getSubExpr()->getLocStart(),
diag::err_asm_invalid_lvalue_in_output)
<< OutputExpr->getSubExpr()->getSourceRange();
}
}
for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) {
StringLiteral *Literal = Constraints[i];
if (Literal->isWide())
// FIXME: We currently leak memory here.
return 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(),
NumOutputs, info)) {
// FIXME: We currently leak memory here.
return Diag(Literal->getLocStart(),
diag::err_asm_invalid_input_constraint) << InputConstraint;
}
// Check that the input exprs aren't of type void.
ParenExpr *InputExpr = cast<ParenExpr>(Exprs[i]);
if (InputExpr->getType()->isVoidType()) {
// FIXME: We currently leak memory here.
return Diag(InputExpr->getSubExpr()->getLocStart(),
diag::err_asm_invalid_type_in_input)
<< InputExpr->getType() << InputConstraint
<< InputExpr->getSubExpr()->getSourceRange();
}
}
// Check that the clobbers are valid.
for (unsigned i = 0; i != NumClobbers; i++) {
StringLiteral *Literal = Clobbers[i];
if (Literal->isWide())
// FIXME: We currently leak memory here.
return 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()))
// FIXME: We currently leak memory here.
return Diag(Literal->getLocStart(),
diag::err_asm_unknown_register_name) << Clobber.c_str();
}
return new AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs,
Names, Constraints, Exprs, AsmString, NumClobbers,
Clobbers, RParenLoc);
}
Action::StmtResult
Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
SourceLocation RParen, StmtTy *Parm,
StmtTy *Body, StmtTy *CatchList) {
ObjCAtCatchStmt *CS = new ObjCAtCatchStmt(AtLoc, RParen,
static_cast<Stmt*>(Parm), static_cast<Stmt*>(Body),
static_cast<Stmt*>(CatchList));
return CatchList ? CatchList : CS;
}
Action::StmtResult
Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtTy *Body) {
ObjCAtFinallyStmt *FS = new ObjCAtFinallyStmt(AtLoc,
static_cast<Stmt*>(Body));
return FS;
}
Action::StmtResult
Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc,
StmtTy *Try, StmtTy *Catch, StmtTy *Finally) {
ObjCAtTryStmt *TS = new ObjCAtTryStmt(AtLoc, static_cast<Stmt*>(Try),
static_cast<Stmt*>(Catch),
static_cast<Stmt*>(Finally));
return TS;
}
Action::StmtResult
Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, StmtTy *Throw) {
ObjCAtThrowStmt *TS = new ObjCAtThrowStmt(AtLoc, static_cast<Stmt*>(Throw));
return TS;
}
Action::StmtResult
Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprTy *SynchExpr,
StmtTy *SynchBody) {
ObjCAtSynchronizedStmt *SS = new ObjCAtSynchronizedStmt(AtLoc,
static_cast<Stmt*>(SynchExpr), static_cast<Stmt*>(SynchBody));
return SS;
}
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