[clang] bdad0a1 - PR45083: Mark statement expressions as being dependent if they appear in
Benjamin Kramer via cfe-commits
cfe-commits at lists.llvm.org
Thu Mar 5 06:13:20 PST 2020
creduce produced this. It's a crash on invalid, but was created from a
valid input.
$ cat r.ii
template <class a> auto b(a) {
auto c = [](auto, int) -> decltype(({})) {};
return c(0, 0);
}
using d = decltype(b(0));
bool f = d ::e;
$ clang r.ii -std=c++17 -w
clang-11: clang/lib/AST/Decl.cpp:2343: clang::APValue
*clang::VarDecl::evaluateValue(SmallVectorImpl<clang::PartialDiagnosticAt>
&) const: Assertion `!Init->isValueDep
endent()' failed.
On Thu, Mar 5, 2020 at 2:18 PM Benjamin Kramer <benny.kra at gmail.com> wrote:
>
> It's still crashing clang, reverted this and
> f545ede91c9d9f271e7504282cab7bf509607ead in 66addf8e8036. c-reduce is
> still chewing on the reproducer.
>
> On Wed, Mar 4, 2020 at 10:20 PM Richard Smith via cfe-commits
> <cfe-commits at lists.llvm.org> wrote:
> >
> > We found a regression introduced by this patch; fixed in f545ede91c9d9f271e7504282cab7bf509607ead.
> >
> > On Wed, 4 Mar 2020 at 00:30, Hans Wennborg via cfe-commits <cfe-commits at lists.llvm.org> wrote:
> >>
> >> Pushed to 10.x as 3a843031a5ad83a00d2603f623881cb2b2bf719d. Please let
> >> me know if you hear about any follow-up issues.
> >>
> >> Thanks!
> >>
> >> On Wed, Mar 4, 2020 at 12:28 AM Richard Smith via cfe-commits
> >> <cfe-commits at lists.llvm.org> wrote:
> >> >
> >> >
> >> > Author: Richard Smith
> >> > Date: 2020-03-03T15:20:40-08:00
> >> > New Revision: bdad0a1b79273733df9acc1be4e992fa5d70ec56
> >> >
> >> > URL: https://github.com/llvm/llvm-project/commit/bdad0a1b79273733df9acc1be4e992fa5d70ec56
> >> > DIFF: https://github.com/llvm/llvm-project/commit/bdad0a1b79273733df9acc1be4e992fa5d70ec56.diff
> >> >
> >> > LOG: PR45083: Mark statement expressions as being dependent if they appear in
> >> > dependent contexts.
> >> >
> >> > We previously assumed they were neither value- nor
> >> > instantiation-dependent under any circumstances, which would lead to
> >> > crashes and other misbehavior.
> >> >
> >> > Added:
> >> >
> >> >
> >> > Modified:
> >> > clang/include/clang/AST/Expr.h
> >> > clang/include/clang/Sema/Sema.h
> >> > clang/lib/AST/ASTImporter.cpp
> >> > clang/lib/Parse/ParseExpr.cpp
> >> > clang/lib/Sema/SemaExpr.cpp
> >> > clang/lib/Sema/SemaExprCXX.cpp
> >> > clang/lib/Sema/TreeTransform.h
> >> > clang/test/SemaTemplate/dependent-expr.cpp
> >> >
> >> > Removed:
> >> >
> >> >
> >> >
> >> > ################################################################################
> >> > diff --git a/clang/include/clang/AST/Expr.h b/clang/include/clang/AST/Expr.h
> >> > index fcdb0b992134..87f9b883486a 100644
> >> > --- a/clang/include/clang/AST/Expr.h
> >> > +++ b/clang/include/clang/AST/Expr.h
> >> > @@ -3960,14 +3960,14 @@ class StmtExpr : public Expr {
> >> > Stmt *SubStmt;
> >> > SourceLocation LParenLoc, RParenLoc;
> >> > public:
> >> > - // FIXME: Does type-dependence need to be computed
> >> > diff erently?
> >> > - // FIXME: Do we need to compute instantiation instantiation-dependence for
> >> > - // statements? (ugh!)
> >> > StmtExpr(CompoundStmt *substmt, QualType T,
> >> > - SourceLocation lp, SourceLocation rp) :
> >> > + SourceLocation lp, SourceLocation rp, bool InDependentContext) :
> >> > + // Note: we treat a statement-expression in a dependent context as always
> >> > + // being value- and instantiation-dependent. This matches the behavior of
> >> > + // lambda-expressions and GCC.
> >> > Expr(StmtExprClass, T, VK_RValue, OK_Ordinary,
> >> > - T->isDependentType(), false, false, false),
> >> > - SubStmt(substmt), LParenLoc(lp), RParenLoc(rp) { }
> >> > + T->isDependentType(), InDependentContext, InDependentContext, false),
> >> > + SubStmt(substmt), LParenLoc(lp), RParenLoc(rp) {}
> >> >
> >> > /// Build an empty statement expression.
> >> > explicit StmtExpr(EmptyShell Empty) : Expr(StmtExprClass, Empty) { }
> >> >
> >> > diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
> >> > index 2304a9718567..5739808753e3 100644
> >> > --- a/clang/include/clang/Sema/Sema.h
> >> > +++ b/clang/include/clang/Sema/Sema.h
> >> > @@ -4964,7 +4964,7 @@ class Sema final {
> >> > LabelDecl *TheDecl);
> >> >
> >> > void ActOnStartStmtExpr();
> >> > - ExprResult ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt,
> >> > + ExprResult ActOnStmtExpr(Scope *S, SourceLocation LPLoc, Stmt *SubStmt,
> >> > SourceLocation RPLoc); // "({..})"
> >> > // Handle the final expression in a statement expression.
> >> > ExprResult ActOnStmtExprResult(ExprResult E);
> >> >
> >> > diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
> >> > index 52288318337d..0cf00f6ca15b 100644
> >> > --- a/clang/lib/AST/ASTImporter.cpp
> >> > +++ b/clang/lib/AST/ASTImporter.cpp
> >> > @@ -6631,8 +6631,9 @@ ExpectedStmt ASTNodeImporter::VisitStmtExpr(StmtExpr *E) {
> >> > if (Err)
> >> > return std::move(Err);
> >> >
> >> > - return new (Importer.getToContext()) StmtExpr(
> >> > - ToSubStmt, ToType, ToLParenLoc, ToRParenLoc);
> >> > + return new (Importer.getToContext())
> >> > + StmtExpr(ToSubStmt, ToType, ToLParenLoc, ToRParenLoc,
> >> > + E->isInstantiationDependent());
> >> > }
> >> >
> >> > ExpectedStmt ASTNodeImporter::VisitUnaryOperator(UnaryOperator *E) {
> >> >
> >> > diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
> >> > index 584de6b87d90..b038e6935d87 100644
> >> > --- a/clang/lib/Parse/ParseExpr.cpp
> >> > +++ b/clang/lib/Parse/ParseExpr.cpp
> >> > @@ -2655,7 +2655,8 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
> >> >
> >> > // If the substmt parsed correctly, build the AST node.
> >> > if (!Stmt.isInvalid()) {
> >> > - Result = Actions.ActOnStmtExpr(OpenLoc, Stmt.get(), Tok.getLocation());
> >> > + Result = Actions.ActOnStmtExpr(getCurScope(), OpenLoc, Stmt.get(),
> >> > + Tok.getLocation());
> >> > } else {
> >> > Actions.ActOnStmtExprError();
> >> > }
> >> >
> >> > diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
> >> > index f50a77a40510..1870e440199d 100644
> >> > --- a/clang/lib/Sema/SemaExpr.cpp
> >> > +++ b/clang/lib/Sema/SemaExpr.cpp
> >> > @@ -13911,9 +13911,8 @@ void Sema::ActOnStmtExprError() {
> >> > PopExpressionEvaluationContext();
> >> > }
> >> >
> >> > -ExprResult
> >> > -Sema::ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt,
> >> > - SourceLocation RPLoc) { // "({..})"
> >> > +ExprResult Sema::ActOnStmtExpr(Scope *S, SourceLocation LPLoc, Stmt *SubStmt,
> >> > + SourceLocation RPLoc) { // "({..})"
> >> > assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!");
> >> > CompoundStmt *Compound = cast<CompoundStmt>(SubStmt);
> >> >
> >> > @@ -13942,9 +13941,18 @@ Sema::ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt,
> >> > }
> >> > }
> >> >
> >> > + bool IsDependentContext = false;
> >> > + if (S)
> >> > + IsDependentContext = S->getTemplateParamParent() != nullptr;
> >> > + else
> >> > + // FIXME: This is not correct when substituting inside a templated
> >> > + // context that isn't a DeclContext (such as a variable template).
> >> > + IsDependentContext = CurContext->isDependentContext();
> >> > +
> >> > // FIXME: Check that expression type is complete/non-abstract; statement
> >> > // expressions are not lvalues.
> >> > - Expr *ResStmtExpr = new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc);
> >> > + Expr *ResStmtExpr =
> >> > + new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc, IsDependentContext);
> >> > if (StmtExprMayBindToTemp)
> >> > return MaybeBindToTemporary(ResStmtExpr);
> >> > return ResStmtExpr;
> >> >
> >> > diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
> >> > index c8c6d7c95a7f..e521ba1d4af1 100644
> >> > --- a/clang/lib/Sema/SemaExprCXX.cpp
> >> > +++ b/clang/lib/Sema/SemaExprCXX.cpp
> >> > @@ -6955,8 +6955,9 @@ Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) {
> >> > // a new AsmStmtWithTemporaries.
> >> > CompoundStmt *CompStmt = CompoundStmt::Create(
> >> > Context, SubStmt, SourceLocation(), SourceLocation());
> >> > - Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(),
> >> > - SourceLocation());
> >> > + Expr *E = new (Context)
> >> > + StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), SourceLocation(),
> >> > + CurContext->isDependentContext());
> >> > return MaybeCreateExprWithCleanups(E);
> >> > }
> >> >
> >> >
> >> > diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
> >> > index 002b73c3a1dd..05b41aa53da6 100644
> >> > --- a/clang/lib/Sema/TreeTransform.h
> >> > +++ b/clang/lib/Sema/TreeTransform.h
> >> > @@ -2549,10 +2549,9 @@ class TreeTransform {
> >> > ///
> >> > /// By default, performs semantic analysis to build the new expression.
> >> > /// Subclasses may override this routine to provide
> >> > diff erent behavior.
> >> > - ExprResult RebuildStmtExpr(SourceLocation LParenLoc,
> >> > - Stmt *SubStmt,
> >> > - SourceLocation RParenLoc) {
> >> > - return getSema().ActOnStmtExpr(LParenLoc, SubStmt, RParenLoc);
> >> > + ExprResult RebuildStmtExpr(SourceLocation LParenLoc, Stmt *SubStmt,
> >> > + SourceLocation RParenLoc) {
> >> > + return getSema().ActOnStmtExpr(nullptr, LParenLoc, SubStmt, RParenLoc);
> >> > }
> >> >
> >> > /// Build a new __builtin_choose_expr expression.
> >> > @@ -11888,6 +11887,8 @@ TreeTransform<Derived>::TransformLambdaExpr(LambdaExpr *E) {
> >> > NewTrailingRequiresClause = getDerived().TransformExpr(TRC);
> >> >
> >> > // Create the local class that will describe the lambda.
> >> > + // FIXME: KnownDependent below is wrong when substituting inside a templated
> >> > + // context that isn't a DeclContext (such as a variable template).
> >> > CXXRecordDecl *OldClass = E->getLambdaClass();
> >> > CXXRecordDecl *Class
> >> > = getSema().createLambdaClosureType(E->getIntroducerRange(),
> >> >
> >> > diff --git a/clang/test/SemaTemplate/dependent-expr.cpp b/clang/test/SemaTemplate/dependent-expr.cpp
> >> > index bb1e239c3490..e333ed927b9e 100644
> >> > --- a/clang/test/SemaTemplate/dependent-expr.cpp
> >> > +++ b/clang/test/SemaTemplate/dependent-expr.cpp
> >> > @@ -1,5 +1,4 @@
> >> > // RUN: %clang_cc1 -fsyntax-only -verify %s
> >> > -// expected-no-diagnostics
> >> >
> >> > // PR5908
> >> > template <typename Iterator>
> >> > @@ -108,3 +107,22 @@ namespace PR18152 {
> >> > };
> >> > template struct A<0>;
> >> > }
> >> > +
> >> > +template<typename T> void stmt_expr_1() {
> >> > + static_assert( ({ false; }), "" );
> >> > +}
> >> > +void stmt_expr_2() {
> >> > + static_assert( ({ false; }), "" ); // expected-error {{failed}}
> >> > +}
> >> > +
> >> > +namespace PR45083 {
> >> > + struct A { bool x; };
> >> > +
> >> > + template<typename> struct B : A {
> >> > + void f() {
> >> > + const int n = ({ if (x) {} 0; });
> >> > + }
> >> > + };
> >> > +
> >> > + template void B<int>::f();
> >> > +}
> >> >
> >> >
> >> >
> >> > _______________________________________________
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