hokein created this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
Fix a crash when evaluating a constexpr function which contains
recovery-exprs. https://bugs.llvm.org/show_bug.cgi?id=46837
Would be nice to have constant expression evaluator support general template
value-dependent expressions, but it requires more work.
This patch is a good start I think, to handle the error-only
value-dependent expressions.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D84637
Files:
clang/lib/AST/ExprConstant.cpp
clang/test/SemaCXX/constexpr-function-recovery-crash.cpp
clang/test/SemaCXX/enable_if.cpp
clang/test/SemaCXX/recovery-expr-type.cpp
Index: clang/test/SemaCXX/recovery-expr-type.cpp
===================================================================
--- clang/test/SemaCXX/recovery-expr-type.cpp
+++ clang/test/SemaCXX/recovery-expr-type.cpp
@@ -53,14 +53,12 @@
return 2;
}
static constexpr int foo2() {
- return AA<T>::getB(); // expected-error{{no matching function for call to 'getB'}} \
- // expected-note {{subexpression not valid in a constant expression}}
+ return AA<T>::getB(); // expected-error{{no matching function for call to 'getB'}}
}
};
// FIXME: should we suppress the "be initialized by a constant expression" diagnostic?
constexpr auto x2 = AA<int>::foo2(); // expected-error {{be initialized by a constant expression}} \
- // expected-note {{in instantiation of member function}} \
- // expected-note {{in call to}}
+ // expected-note {{in instantiation of member function}}
}
// verify no assertion failure on violating value category.
Index: clang/test/SemaCXX/enable_if.cpp
===================================================================
--- clang/test/SemaCXX/enable_if.cpp
+++ clang/test/SemaCXX/enable_if.cpp
@@ -415,7 +415,7 @@
template <int N> constexpr int callTemplated() { return templated<N>(); }
constexpr int B = 10 + // expected-error {{initialized by a constant expression}}
- callTemplated<0>(); // expected-error@-3{{no matching function for call to 'templated'}} expected-note{{in instantiation of function template}} expected-note@-10{{candidate disabled}} expected-note {{in call to 'callTemplated()'}} expected-note@-3 {{subexpression not valid in a constant expression}}
+ callTemplated<0>(); // expected-error@-3{{no matching function for call to 'templated'}} expected-note{{in instantiation of function template}} expected-note@-10{{candidate disabled}}
static_assert(callTemplated<1>() == 1, "");
}
Index: clang/test/SemaCXX/constexpr-function-recovery-crash.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/constexpr-function-recovery-crash.cpp
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 %s -std=c++20 -fsyntax-only -verify
+
+// verify no value-dependent-assertion crash in constexpr function body.
+class Foo {
+ constexpr Foo() {
+ while (invalid()) {} // expected-error {{use of undeclared identifier}}
+ if (invalid()) {} // expected-error {{use of undeclared identifier}}
+ }
+};
+
+constexpr void test1() {
+ while (invalid()) {} // expected-error {{use of undeclared identifier}}
+ if (invalid()) {} // expected-error {{use of undeclared identifier}}
+}
\ No newline at end of file
Index: clang/lib/AST/ExprConstant.cpp
===================================================================
--- clang/lib/AST/ExprConstant.cpp
+++ clang/lib/AST/ExprConstant.cpp
@@ -1868,6 +1868,7 @@
/// result.
/// \return \c true if the caller should keep evaluating.
static bool EvaluateIgnoredValue(EvalInfo &Info, const Expr *E) {
+ assert(!E->isValueDependent());
APValue Scratch;
if (!Evaluate(Scratch, Info, E))
// We don't need the value, but we might have skipped a side effect here.
@@ -2369,6 +2370,7 @@
static bool EvaluateAsBooleanCondition(const Expr *E, bool &Result,
EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && "missing lvalue-to-rvalue conv in bool condition");
APValue Val;
if (!Evaluate(Val, Info, E))
@@ -4611,6 +4613,7 @@
/// Evaluate a condition (either a variable declaration or an expression).
static bool EvaluateCond(EvalInfo &Info, const VarDecl *CondDecl,
const Expr *Cond, bool &Result) {
+ assert(!Cond->isValueDependent());
FullExpressionRAII Scope(Info);
if (CondDecl && !EvaluateDecl(Info, CondDecl))
return false;
@@ -4868,6 +4871,10 @@
switch (S->getStmtClass()) {
default:
if (const Expr *E = dyn_cast<Expr>(S)) {
+ if (E->isValueDependent()) {
+ assert(E->containsErrors());
+ return ESR_Failed;
+ }
// Don't bother evaluating beyond an expression-statement which couldn't
// be evaluated.
// FIXME: Do we need the FullExpressionRAII object here?
@@ -4900,6 +4907,10 @@
case Stmt::ReturnStmtClass: {
const Expr *RetExpr = cast<ReturnStmt>(S)->getRetValue();
FullExpressionRAII Scope(Info);
+ if (RetExpr && RetExpr->isValueDependent()) {
+ assert(RetExpr->containsErrors());
+ return ESR_Failed;
+ }
if (RetExpr &&
!(Result.Slot
? EvaluateInPlace(Result.Value, Info, *Result.Slot, RetExpr)
@@ -4940,6 +4951,10 @@
return ESR;
}
}
+ if (IS->getCond()->isValueDependent()) {
+ assert(IS->getCond()->containsErrors());
+ return ESR_Failed;
+ }
bool Cond;
if (!EvaluateCond(Info, IS->getConditionVariable(), IS->getCond(), Cond))
return ESR_Failed;
@@ -4958,6 +4973,10 @@
case Stmt::WhileStmtClass: {
const WhileStmt *WS = cast<WhileStmt>(S);
while (true) {
+ if (WS->getCond()->isValueDependent()) {
+ assert(WS->getCond()->containsErrors());
+ return ESR_Failed;
+ }
BlockScopeRAII Scope(Info);
bool Continue;
if (!EvaluateCond(Info, WS->getConditionVariable(), WS->getCond(),
@@ -4987,6 +5006,10 @@
return ESR;
Case = nullptr;
+ if (DS->getCond()->isValueDependent()) {
+ assert(DS->getCond()->containsErrors());
+ return ESR_Failed;
+ }
FullExpressionRAII CondScope(Info);
if (!EvaluateAsBooleanCondition(DS->getCond(), Continue, Info) ||
!CondScope.destroy())
@@ -5007,6 +5030,10 @@
}
}
while (true) {
+ if (FS->getCond() && FS->getCond()->isValueDependent()) {
+ assert(FS->getCond()->containsErrors());
+ return ESR_Failed;
+ }
BlockScopeRAII IterScope(Info);
bool Continue = true;
if (FS->getCond() && !EvaluateCond(Info, FS->getConditionVariable(),
@@ -5073,6 +5100,10 @@
while (true) {
// Condition: __begin != __end.
{
+ if (FS->getCond()->isValueDependent()) {
+ assert(FS->getCond()->containsErrors());
+ return ESR_Failed;
+ }
bool Continue = true;
FullExpressionRAII CondExpr(Info);
if (!EvaluateAsBooleanCondition(FS->getCond(), Continue, Info))
@@ -5097,6 +5128,10 @@
return ESR_Failed;
return ESR;
}
+ if (FS->getInc()->isValueDependent()) {
+ assert(FS->getInc()->containsErrors());
+ return ESR_Failed;
+ }
// Increment: ++__begin
if (!EvaluateIgnoredValue(Info, FS->getInc()))
@@ -7750,6 +7785,7 @@
/// * @selector() expressions in Objective-C
static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
bool InvalidBaseOK) {
+ assert(!E->isValueDependent());
assert(E->isGLValue() || E->getType()->isFunctionType() ||
E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E));
return LValueExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
@@ -8280,6 +8316,7 @@
static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info,
bool InvalidBaseOK) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->hasPointerRepresentation());
return PointerExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
}
@@ -9157,6 +9194,7 @@
static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->isMemberPointerType());
return MemberPointerExprEvaluator(Info, Result).Visit(E);
}
@@ -9631,6 +9669,7 @@
static bool EvaluateRecord(const Expr *E, const LValue &This,
APValue &Result, EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->isRecordType() &&
"can't evaluate expression as a record rvalue");
return RecordExprEvaluator(Info, This, Result).Visit(E);
@@ -9686,6 +9725,7 @@
/// Evaluate an expression of record type as a temporary.
static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->isRecordType());
return TemporaryExprEvaluator(Info, Result).Visit(E);
}
@@ -9972,6 +10012,7 @@
static bool EvaluateArray(const Expr *E, const LValue &This,
APValue &Result, EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->isArrayType() && "not an array rvalue");
return ArrayExprEvaluator(Info, This, Result).Visit(E);
}
@@ -9979,6 +10020,7 @@
static bool EvaluateArrayNewInitList(EvalInfo &Info, LValue &This,
APValue &Result, const InitListExpr *ILE,
QualType AllocType) {
+ assert(!ILE->isValueDependent());
assert(ILE->isRValue() && ILE->getType()->isArrayType() &&
"not an array rvalue");
return ArrayExprEvaluator(Info, This, Result)
@@ -9989,6 +10031,7 @@
APValue &Result,
const CXXConstructExpr *CCE,
QualType AllocType) {
+ assert(!CCE->isValueDependent());
assert(CCE->isRValue() && CCE->getType()->isArrayType() &&
"not an array rvalue");
return ArrayExprEvaluator(Info, This, Result)
@@ -10366,11 +10409,13 @@
/// like char*).
static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->isIntegralOrEnumerationType());
return IntExprEvaluator(Info, Result).Visit(E);
}
static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info) {
+ assert(!E->isValueDependent());
APValue Val;
if (!EvaluateIntegerOrLValue(E, Val, Info))
return false;
@@ -10392,6 +10437,7 @@
static bool EvaluateFixedPoint(const Expr *E, APFixedPoint &Result,
EvalInfo &Info) {
+ assert(!E->isValueDependent());
if (E->getType()->isFixedPointType()) {
APValue Val;
if (!FixedPointExprEvaluator(Info, Val).Visit(E))
@@ -10407,6 +10453,7 @@
static bool EvaluateFixedPointOrInteger(const Expr *E, APFixedPoint &Result,
EvalInfo &Info) {
+ assert(!E->isValueDependent());
if (E->getType()->isIntegerType()) {
auto FXSema = Info.Ctx.getFixedPointSemantics(E->getType());
APSInt Val;
@@ -12026,6 +12073,7 @@
static bool
EvaluateComparisonBinaryOperator(EvalInfo &Info, const BinaryOperator *E,
SuccessCB &&Success, AfterCB &&DoAfter) {
+ assert(!E->isValueDependent());
assert(E->isComparisonOp() && "expected comparison operator");
assert((E->getOpcode() == BO_Cmp ||
E->getType()->isIntegralOrEnumerationType()) &&
@@ -13054,6 +13102,7 @@
} // end anonymous namespace
static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->isRealFloatingType());
return FloatExprEvaluator(Info, Result).Visit(E);
}
@@ -13287,6 +13336,7 @@
static bool EvaluateComplex(const Expr *E, ComplexValue &Result,
EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->isAnyComplexType());
return ComplexExprEvaluator(Info, Result).Visit(E);
}
@@ -13809,6 +13859,7 @@
static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->isAtomicType());
return AtomicExprEvaluator(Info, This, Result).Visit(E);
}
@@ -13933,6 +13984,7 @@
}
static bool EvaluateVoid(const Expr *E, EvalInfo &Info) {
+ assert(!E->isValueDependent());
assert(E->isRValue() && E->getType()->isVoidType());
return VoidExprEvaluator(Info).Visit(E);
}
@@ -13942,6 +13994,7 @@
//===----------------------------------------------------------------------===//
static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E) {
+ assert(!E->isValueDependent());
// In C, function designators are not lvalues, but we evaluate them as if they
// are.
QualType T = E->getType();
@@ -14052,6 +14105,7 @@
/// EvaluateAsRValue - Try to evaluate this expression, performing an implicit
/// lvalue-to-rvalue cast if it is an lvalue.
static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result) {
+ assert(!E->isValueDependent());
if (Info.EnableNewConstInterp) {
if (!Info.Ctx.getInterpContext().evaluateAsRValue(Info, E, Result))
return false;
@@ -14115,6 +14169,7 @@
static bool EvaluateAsRValue(const Expr *E, Expr::EvalResult &Result,
const ASTContext &Ctx, EvalInfo &Info) {
+ assert(!E->isValueDependent());
bool IsConst;
if (FastEvaluateAsRValue(E, Result, Ctx, IsConst))
return IsConst;
@@ -14126,6 +14181,7 @@
const ASTContext &Ctx,
Expr::SideEffectsKind AllowSideEffects,
EvalInfo &Info) {
+ assert(!E->isValueDependent());
if (!E->getType()->isIntegralOrEnumerationType())
return false;
@@ -14141,6 +14197,7 @@
const ASTContext &Ctx,
Expr::SideEffectsKind AllowSideEffects,
EvalInfo &Info) {
+ assert(!E->isValueDependent());
if (!E->getType()->isFixedPointType())
return false;
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