[clang] 6f428e0 - [AST] Fix crashes on decltype(recovery-expr).

Yung, Douglas via cfe-commits cfe-commits at lists.llvm.org
Wed Apr 1 11:28:22 PDT 2020


Hi Haojian,

I noticed that after your change, the compiler is now giving an error when trying to create a vector of >= 1024 elements when previously it worked, and gcc has no problem with the same code. Is that intentional? I have put the details in PR45387, can you take a look?

Douglas Yung

-----Original Message-----
From: cfe-commits <cfe-commits-bounces at lists.llvm.org> On Behalf Of Haojian Wu via cfe-commits
Sent: Monday, March 30, 2020 5:57
To: cfe-commits at lists.llvm.org
Subject: [clang] 6f428e0 - [AST] Fix crashes on decltype(recovery-expr).


Author: Haojian Wu
Date: 2020-03-30T14:56:33+02:00
New Revision: 6f428e09fbe8ce7e3510ae024031a5fc19653483

URL: https://github.com/llvm/llvm-project/commit/6f428e09fbe8ce7e3510ae024031a5fc19653483
DIFF: https://github.com/llvm/llvm-project/commit/6f428e09fbe8ce7e3510ae024031a5fc19653483.diff

LOG: [AST] Fix crashes on decltype(recovery-expr).

Summary: We mark these decls as invalid.

Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77037

Added: 
    

Modified: 
    clang/include/clang/AST/DependenceFlags.h
    clang/include/clang/AST/Type.h
    clang/lib/Parse/ParseExprCXX.cpp
    clang/lib/Sema/SemaType.cpp
    clang/test/AST/ast-dump-expr-errors.cpp
    clang/test/Sema/invalid-member.cpp
    clang/unittests/Sema/CodeCompleteTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/AST/DependenceFlags.h b/clang/include/clang/AST/DependenceFlags.h
index 75c9aa1656b8..0b24bae6df9b 100644
--- a/clang/include/clang/AST/DependenceFlags.h
+++ b/clang/include/clang/AST/DependenceFlags.h
@@ -50,14 +50,16 @@ struct TypeDependenceScope {
     /// Whether this type is a variably-modified type (C99 6.7.5).
     VariablyModified = 8,
 
-    // FIXME: add Error bit.
+    /// Whether this type references an error, e.g. decltype(err-expression)
+    /// yields an error type.
+    Error = 16,
 
     None = 0,
-    All = 15,
+    All = 31,
 
     DependentInstantiation = Dependent | Instantiation,
 
-    LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/VariablyModified)
+    LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/Error)
   };
 };
 using TypeDependence = TypeDependenceScope::TypeDependence;
@@ -147,6 +149,7 @@ class Dependence {
     return translate(V, UnexpandedPack, TypeDependence::UnexpandedPack) |
            translate(V, Instantiation, TypeDependence::Instantiation) |
            translate(V, Dependent, TypeDependence::Dependent) |
+           translate(V, Error, TypeDependence::Error) |
            translate(V, VariablyModified, TypeDependence::VariablyModified);
   }
 

diff  --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h index 248fbcfba98e..5d2c035ea0fe 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -2139,6 +2139,11 @@ class alignas(8) Type : public ExtQualsTypeCommonBase {
     return static_cast<TypeDependence>(TypeBits.Dependence);
   }
 
+  /// Whether this type is an error type.
+  bool containsErrors() const {
+    return getDependence() & TypeDependence::Error;  }
+
   /// Whether this type is a dependent type, meaning that its definition
   /// somehow depends on a template parameter (C++ [temp.dep.type]).
   bool isDependentType() const {

diff  --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp
index 761fad9456be..4389c8777c6d 100644
--- a/clang/lib/Parse/ParseExprCXX.cpp
+++ b/clang/lib/Parse/ParseExprCXX.cpp
@@ -3105,10 +3105,14 @@ Parser::ParseCXXNewExpression(bool UseGlobal, SourceLocation Start) {
       auto RunSignatureHelp = [&]() {
         ParsedType TypeRep =
             Actions.ActOnTypeName(getCurScope(), DeclaratorInfo).get();
-        assert(TypeRep && "invalid types should be handled before");
-        QualType PreferredType = Actions.ProduceConstructorSignatureHelp(
-            getCurScope(), TypeRep.get()->getCanonicalTypeInternal(),
-            DeclaratorInfo.getEndLoc(), ConstructorArgs, ConstructorLParen);
+        QualType PreferredType;
+        // ActOnTypeName might adjust DeclaratorInfo and return a null type even
+        // the passing DeclaratorInfo is valid, e.g. running SignatureHelp on
+        // `new decltype(invalid) (^)`.
+        if (TypeRep)
+          PreferredType = Actions.ProduceConstructorSignatureHelp(
+              getCurScope(), TypeRep.get()->getCanonicalTypeInternal(),
+              DeclaratorInfo.getEndLoc(), ConstructorArgs, 
+ ConstructorLParen);
         CalledSignatureHelp = true;
         return PreferredType;
       };

diff  --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp index 55ce028fb8c2..e128ebf31270 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -1678,6 +1678,12 @@ static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
     break;
   }
 
+  // FIXME: we want resulting declarations to be marked invalid, but 
+ claiming  // the type is invalid is too strong - e.g. it causes 
+ ActOnTypeName to return  // a null type.
+  if (Result->containsErrors())
+    declarator.setInvalidType();
+
   if (S.getLangOpts().OpenCL &&
       S.checkOpenCLDisabledTypeDeclSpec(DS, Result))
     declarator.setInvalidType(true);

diff  --git a/clang/test/AST/ast-dump-expr-errors.cpp b/clang/test/AST/ast-dump-expr-errors.cpp
index e623fad04f4c..9334b73a4354 100644
--- a/clang/test/AST/ast-dump-expr-errors.cpp
+++ b/clang/test/AST/ast-dump-expr-errors.cpp
@@ -42,5 +42,9 @@ int d = static_cast<int>(bar() + 1);
 
 // FIXME: store initializer even when 'auto' could not be deduced.
 // Expressions with errors currently do not keep initializers around.
-// CHECK:     `-VarDecl {{.*}} invalid e 'auto'
+// CHECK: -VarDecl {{.*}} invalid e 'auto'
 auto e = bar();
+
+// Error type should result in an invalid decl.
+// CHECK: -VarDecl {{.*}} invalid f 'decltype(<recovery-expr>(bar))'
+decltype(bar()) f;

diff  --git a/clang/test/Sema/invalid-member.cpp b/clang/test/Sema/invalid-member.cpp
index 5475157e936e..544979980fc9 100644
--- a/clang/test/Sema/invalid-member.cpp
+++ b/clang/test/Sema/invalid-member.cpp
@@ -1,7 +1,15 @@
-// RUN: %clang_cc1 -verify -fsyntax-only %s -void foo(); // expected-note {{requires 0 arguments}}
+// RUN: %clang_cc1 -verify -fsyntax-only -fno-recovery-ast %s // RUN: 
+%clang_cc1 -verify -fsyntax-only -frecovery-ast %s
+
+void foo(); // expected-note 2{{requires 0 arguments}}
 class X {
   decltype(foo(42)) invalid; // expected-error {{no matching function}}  };  // Should be able to evaluate sizeof without crashing.
 static_assert(sizeof(X) == 1, "No valid members");
+
+class Y {
+  typeof(foo(42)) invalid; // expected-error {{no matching function}} 
+}; // Should be able to evaluate sizeof without crashing.
+static_assert(sizeof(Y) == 1, "No valid members");

diff  --git a/clang/unittests/Sema/CodeCompleteTest.cpp b/clang/unittests/Sema/CodeCompleteTest.cpp
index a9441a679cac..d8b303d77bb9 100644
--- a/clang/unittests/Sema/CodeCompleteTest.cpp
+++ b/clang/unittests/Sema/CodeCompleteTest.cpp
@@ -486,7 +486,10 @@ TEST(PreferredTypeTest, NoCrashOnInvalidTypes) {
   StringRef Code = R"cpp(
     auto x = decltype(&1)(^);
     auto y = new decltype(&1)(^);
+    // GNU decimal type extension is not supported in clang.
+    auto z = new _Decimal128(^);
   )cpp";
   EXPECT_THAT(collectPreferredTypes(Code), Each("NULL TYPE"));  }
+
 } // namespace


        
_______________________________________________
cfe-commits mailing list
cfe-commits at lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits


More information about the cfe-commits mailing list