[clang] 5f94c9a - [AST][RecoveryExpr] Add error-bit TemplateArgument

[Haojian Wu via cfe-commits]

Author: Haojian Wu
Date: 2020-06-24T16:21:35+02:00
New Revision: 5f94c9a421ec7cc7ece2bd875e010639ee0783ec

URL: https://github.com/llvm/llvm-project/commit/5f94c9a421ec7cc7ece2bd875e010639ee0783ec
DIFF: https://github.com/llvm/llvm-project/commit/5f94c9a421ec7cc7ece2bd875e010639ee0783ec.diff

LOG: [AST][RecoveryExpr] Add error-bit TemplateArgument

Summary: We are missing the error-bit somehow if the error-bit is propagated
through the code path: "error type/expr" -> "template argument" ->
"template specialization type", which will lead to crashes.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82102

Added: 
    

Modified: 
    clang/include/clang/AST/DependenceFlags.h
    clang/lib/AST/Type.cpp
    clang/test/SemaCXX/invalid-template-base-specifier.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/AST/DependenceFlags.h b/clang/include/clang/AST/DependenceFlags.h
index 54e12ea47fd5..7e044865b254 100644
--- a/clang/include/clang/AST/DependenceFlags.h
+++ b/clang/include/clang/AST/DependenceFlags.h
@@ -64,6 +64,23 @@ struct TypeDependenceScope {
 };
 using TypeDependence = TypeDependenceScope::TypeDependence;
 
+struct TemplateArgumentDependenceScope {
+  enum TemplateArgumentDependence : uint8_t {
+    UnexpandedPack = 1,
+    Instantiation = 2,
+    Dependent = 4,
+
+    Error = 8,
+
+    DependentInstantiation = Dependent | Instantiation,
+    None = 0,
+    All = 15,
+    LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/Error)
+  };
+};
+using TemplateArgumentDependence =
+    TemplateArgumentDependenceScope ::TemplateArgumentDependence;
+
 #define LLVM_COMMON_DEPENDENCE(NAME)                                           \
   struct NAME##Scope {                                                         \
     enum NAME : uint8_t {                                                      \
@@ -82,7 +99,6 @@ using TypeDependence = TypeDependenceScope::TypeDependence;
 
 LLVM_COMMON_DEPENDENCE(NestedNameSpecifierDependence)
 LLVM_COMMON_DEPENDENCE(TemplateNameDependence)
-LLVM_COMMON_DEPENDENCE(TemplateArgumentDependence)
 #undef LLVM_COMMON_DEPENDENCE
 
 // A combined space of all dependence concepts for all node types.
@@ -137,8 +153,9 @@ class Dependence {
 
   Dependence(TemplateArgumentDependence D)
       : V(translate(D, TADependence::UnexpandedPack, UnexpandedPack) |
-             translate(D, TADependence::Instantiation, Instantiation) |
-             translate(D, TADependence::Dependent, Dependent)) {}
+          translate(D, TADependence::Instantiation, Instantiation) |
+          translate(D, TADependence::Dependent, Dependent) |
+          translate(D, TADependence::Error, Error)) {}
 
   Dependence(TemplateNameDependence D)
       : V(translate(D, TNDependence::UnexpandedPack, UnexpandedPack) |
@@ -170,7 +187,8 @@ class Dependence {
   TemplateArgumentDependence templateArgument() const {
     return translate(V, UnexpandedPack, TADependence::UnexpandedPack) |
            translate(V, Instantiation, TADependence::Instantiation) |
-           translate(V, Dependent, TADependence::Dependent);
+           translate(V, Dependent, TADependence::Dependent) |
+           translate(V, Error, TADependence::Error);
   }
 
   TemplateNameDependence templateName() const {

diff  --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index ba0d86befe1b..05962f34bbf1 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3591,7 +3591,7 @@ TemplateSpecializationType::TemplateSpecializationType(
 
   auto *TemplateArgs = reinterpret_cast<TemplateArgument *>(this + 1);
   for (const TemplateArgument &Arg : Args) {
-    // Update instantiation-dependent and variably-modified bits.
+    // Update instantiation-dependent, variably-modified, and error bits.
     // If the canonical type exists and is non-dependent, the template
     // specialization type can be non-dependent even if one of the type
     // arguments is. Given:

diff  --git a/clang/test/SemaCXX/invalid-template-base-specifier.cpp b/clang/test/SemaCXX/invalid-template-base-specifier.cpp
index c0f5aabae831..7a1a7f801c45 100644
--- a/clang/test/SemaCXX/invalid-template-base-specifier.cpp
+++ b/clang/test/SemaCXX/invalid-template-base-specifier.cpp
@@ -1,7 +1,6 @@
 // RUN: %clang_cc1 -frecovery-ast -verify %s
 
-bool Foo(int *); // expected-note {{candidate function not viable}} \
-                 // expected-note {{candidate function not viable}}
+bool Foo(int *); // expected-note 3{{candidate function not viable}}
 
 template <typename T>
 struct Crash : decltype(Foo(T())) { // expected-error {{no matching function for call to 'Foo'}}
@@ -18,3 +17,12 @@ struct Crash2 : decltype(Alias<T>()) { // expected-note {{in instantiation of te
 };
 
 void test2() { Crash2<int>(); } // expected-note {{in instantiation of template class 'Crash2<int>' requested here}}
+
+template <typename T>
+class Base {};
+template <typename T>
+struct Crash3 : Base<decltype(Foo(T()))> { // expected-error {{no matching function for call to 'Foo'}}
+  Crash3(){};
+};
+
+void test3() { Crash3<int>(); } // expected-note {{in instantiation of template class}}