[llvm-branch-commits] [clang] be162f4 - PR45699: Fix crash if an unexpanded parameter pack appears in a

Richard Smith via llvm-branch-commits llvm-branch-commits at lists.llvm.org
Thu Dec 3 15:30:29 PST 2020


Author: Richard Smith
Date: 2020-12-03T15:26:06-08:00
New Revision: be162f4c0e8563c8de510121435281ae628c8654

URL: https://github.com/llvm/llvm-project/commit/be162f4c0e8563c8de510121435281ae628c8654
DIFF: https://github.com/llvm/llvm-project/commit/be162f4c0e8563c8de510121435281ae628c8654.diff

LOG: PR45699: Fix crash if an unexpanded parameter pack appears in a
requires-clause.

Added: 
    

Modified: 
    clang/include/clang/AST/ExprCXX.h
    clang/include/clang/AST/RecursiveASTVisitor.h
    clang/include/clang/Basic/DiagnosticSemaKinds.td
    clang/include/clang/Sema/Sema.h
    clang/lib/AST/ExprCXX.cpp
    clang/lib/Parse/ParseTemplate.cpp
    clang/lib/Sema/SemaDeclCXX.cpp
    clang/test/SemaTemplate/concepts.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h
index 2f89b43267b6..1efa78fc4294 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -2029,6 +2029,9 @@ class LambdaExpr final : public Expr,
   /// invented by use of an auto parameter).
   ArrayRef<NamedDecl *> getExplicitTemplateParameters() const;
 
+  /// Get the trailing requires clause, if any.
+  Expr *getTrailingRequiresClause() const;
+
   /// Whether this is a generic lambda.
   bool isGenericLambda() const { return getTemplateParameterList(); }
 

diff  --git a/clang/include/clang/AST/RecursiveASTVisitor.h b/clang/include/clang/AST/RecursiveASTVisitor.h
index 0a36ec9ad687..612e60cf4df1 100644
--- a/clang/include/clang/AST/RecursiveASTVisitor.h
+++ b/clang/include/clang/AST/RecursiveASTVisitor.h
@@ -2503,17 +2503,12 @@ DEF_TRAVERSE_STMT(LambdaExpr, {
     TypeLoc TL = S->getCallOperator()->getTypeSourceInfo()->getTypeLoc();
     FunctionProtoTypeLoc Proto = TL.getAsAdjusted<FunctionProtoTypeLoc>();
 
-    for (Decl *D : S->getExplicitTemplateParameters()) {
-      // Visit explicit template parameters.
-      TRY_TO(TraverseDecl(D));
-    }
+    TRY_TO(TraverseTemplateParameterListHelper(S->getTemplateParameterList()));
     if (S->hasExplicitParameters()) {
       // Visit parameters.
       for (unsigned I = 0, N = Proto.getNumParams(); I != N; ++I)
         TRY_TO(TraverseDecl(Proto.getParam(I)));
     }
-    if (S->hasExplicitResultType())
-      TRY_TO(TraverseTypeLoc(Proto.getReturnLoc()));
 
     auto *T = Proto.getTypePtr();
     for (const auto &E : T->exceptions())
@@ -2522,6 +2517,10 @@ DEF_TRAVERSE_STMT(LambdaExpr, {
     if (Expr *NE = T->getNoexceptExpr())
       TRY_TO_TRAVERSE_OR_ENQUEUE_STMT(NE);
 
+    if (S->hasExplicitResultType())
+      TRY_TO(TraverseTypeLoc(Proto.getReturnLoc()));
+    TRY_TO_TRAVERSE_OR_ENQUEUE_STMT(S->getTrailingRequiresClause());
+
     TRY_TO_TRAVERSE_OR_ENQUEUE_STMT(S->getBody());
   }
   ShouldVisitChildren = false;

diff  --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 44195cc9db45..23f374987c92 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -5158,7 +5158,8 @@ def err_unexpanded_parameter_pack : Error<
   "using declaration|friend declaration|qualifier|initializer|default argument|"
   "non-type template parameter type|exception type|partial specialization|"
   "__if_exists name|__if_not_exists name|lambda|block|type constraint|"
-  "requirement}0 contains%plural{0: an|:}1 unexpanded parameter pack"
+  "requirement|requires clause}0 "
+  "contains%plural{0: an|:}1 unexpanded parameter pack"
   "%plural{0:|1: %2|2:s %2 and %3|:s %2, %3, ...}1">;
 
 def err_pack_expansion_without_parameter_packs : Error<

diff  --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 8b4a18ab11d6..fc19e04e6c5d 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -2674,6 +2674,7 @@ class Sema final {
                                 SkipBodyInfo *SkipBody = nullptr);
   void ActOnStartTrailingRequiresClause(Scope *S, Declarator &D);
   ExprResult ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr);
+  ExprResult ActOnRequiresClause(ExprResult ConstraintExpr);
   void ActOnStartOfObjCMethodDef(Scope *S, Decl *D);
   bool isObjCMethodDecl(Decl *D) {
     return D && isa<ObjCMethodDecl>(D);
@@ -7927,6 +7928,9 @@ class Sema final {
 
     // A requirement in a requires-expression.
     UPPC_Requirement,
+
+    // A requires-clause.
+    UPPC_RequiresClause,
   };
 
   /// Diagnose unexpanded parameter packs.

diff  --git a/clang/lib/AST/ExprCXX.cpp b/clang/lib/AST/ExprCXX.cpp
index b7f677051ea2..8dc9d4296e14 100644
--- a/clang/lib/AST/ExprCXX.cpp
+++ b/clang/lib/AST/ExprCXX.cpp
@@ -1271,6 +1271,10 @@ ArrayRef<NamedDecl *> LambdaExpr::getExplicitTemplateParameters() const {
   return Record->getLambdaExplicitTemplateParameters();
 }
 
+Expr *LambdaExpr::getTrailingRequiresClause() const {
+  return getCallOperator()->getTrailingRequiresClause();
+}
+
 bool LambdaExpr::isMutable() const { return !getCallOperator()->isConst(); }
 
 LambdaExpr::child_range LambdaExpr::children() {

diff  --git a/clang/lib/Parse/ParseTemplate.cpp b/clang/lib/Parse/ParseTemplate.cpp
index 09ffc422e813..828b9b2277ff 100644
--- a/clang/lib/Parse/ParseTemplate.cpp
+++ b/clang/lib/Parse/ParseTemplate.cpp
@@ -141,9 +141,8 @@ Decl *Parser::ParseTemplateDeclarationOrSpecialization(
 
       if (TryConsumeToken(tok::kw_requires)) {
         OptionalRequiresClauseConstraintER =
-            Actions.CorrectDelayedTyposInExpr(
-                ParseConstraintLogicalOrExpression(
-                    /*IsTrailingRequiresClause=*/false));
+            Actions.ActOnRequiresClause(ParseConstraintLogicalOrExpression(
+                /*IsTrailingRequiresClause=*/false));
         if (!OptionalRequiresClauseConstraintER.isUsable()) {
           // Skip until the semi-colon or a '}'.
           SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);

diff  --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 593f4a937c79..0df022f036f2 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -3932,9 +3932,22 @@ void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) {
 }
 
 ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) {
+  return ActOnRequiresClause(ConstraintExpr);
+}
+
+ExprResult Sema::ActOnRequiresClause(ExprResult ConstraintExpr) {
+  if (ConstraintExpr.isInvalid())
+    return ExprError();
+
+  ConstraintExpr = CorrectDelayedTyposInExpr(ConstraintExpr);
   if (ConstraintExpr.isInvalid())
     return ExprError();
-  return CorrectDelayedTyposInExpr(ConstraintExpr);
+
+  if (DiagnoseUnexpandedParameterPack(ConstraintExpr.get(),
+                                      UPPC_RequiresClause))
+    return ExprError();
+
+  return ConstraintExpr;
 }
 
 /// This is invoked after parsing an in-class initializer for a

diff  --git a/clang/test/SemaTemplate/concepts.cpp b/clang/test/SemaTemplate/concepts.cpp
index db154a9a0f5b..d228ff07837d 100644
--- a/clang/test/SemaTemplate/concepts.cpp
+++ b/clang/test/SemaTemplate/concepts.cpp
@@ -23,3 +23,31 @@ namespace PR47025 {
   static_assert(!AllAddable3<int, void>);
   static_assert(!AllAddable6<int, void>);
 }
+
+namespace PR45699 {
+  template<class> concept C = true; // expected-note 2{{here}}
+  template<class ...Ts> void f1a() requires C<Ts>; // expected-error {{requires clause contains unexpanded parameter pack 'Ts'}}
+  template<class ...Ts> requires C<Ts> void f1b(); // expected-error {{requires clause contains unexpanded parameter pack 'Ts'}}
+  template<class ...Ts> void f2a() requires (C<Ts> && ...);
+  template<class ...Ts> requires (C<Ts> && ...) void f2b();
+  template<class ...Ts> void f3a() requires C<Ts...>; // expected-error {{pack expansion used as argument for non-pack parameter of concept}}
+  template<class ...Ts> requires C<Ts...> void f3b(); // expected-error {{pack expansion used as argument for non-pack parameter of concept}}
+  template<class ...Ts> void f4() {
+    ([] () requires C<Ts> {} ()); // expected-error {{expression contains unexpanded parameter pack 'Ts'}}
+    ([]<int = 0> requires C<Ts> () {} ()); // FIXME: expected-error {{lambda requires '()' before 'requires' clause}} expected-error 0+{{}}
+  }
+  template<class ...Ts> void f5() {
+    ([] () requires C<Ts> {} (), ...);
+    ([]<int = 0> requires C<Ts> () {} (), ...); // FIXME: expected-error {{lambda requires '()' before 'requires' clause}} expected-error 0+{{}}
+  }
+  void g() {
+    f1a();
+    f1b(); // FIXME: Bad error recovery. expected-error {{undeclared identifier}}
+    f2a();
+    f2b();
+    f3a();
+    f3b(); // FIXME: Bad error recovery. expected-error {{undeclared identifier}}
+    f4();
+    f5();
+  }
+}


        


More information about the llvm-branch-commits mailing list