[PATCH] D134334: [Clang] Fix crash in isCXXDeclarationSpecifier when attempting to annotate template name

[Shafik Yaghmour via Phabricator via cfe-commits]

shafik created this revision.
shafik added reviewers: aaron.ballman, erichkeane.
Herald added a project: All.
shafik requested review of this revision.

When attempting to decide if in C++17 a type template for class template argument deduction and the code is ill-formed the condition to break is checking the current token is an identifier when it should be checking if the next token is an identifier.

This fixes: https://github.com/llvm/llvm-project/issues/57495


https://reviews.llvm.org/D134334

Files:
  clang/docs/ReleaseNotes.rst
  clang/lib/Parse/ParseTentative.cpp
  clang/test/Parser/cxx1z-class-template-argument-deduction.cpp


Index: clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
===================================================================
--- clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
+++ clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
@@ -248,3 +248,11 @@
 };
 
 }
+
+namespace GH57495 {
+template <typename T> struct vector{};
+
+void f() {
+  GH57495::vector.d; // expected-error {{cannot use dot operator on a type}}
+}
+}
Index: clang/lib/Parse/ParseTentative.cpp
===================================================================
--- clang/lib/Parse/ParseTentative.cpp
+++ clang/lib/Parse/ParseTentative.cpp
@@ -1550,7 +1550,7 @@
             if (getLangOpts().CPlusPlus17) {
               if (TryAnnotateTypeOrScopeToken())
                 return TPResult::Error;
-              if (Tok.isNot(tok::identifier))
+              if (NextToken().isNot(tok::identifier))
                 break;
             }
 
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -160,6 +160,10 @@
   `Issue 53628 <https://github.com/llvm/llvm-project/issues/53628>`_
 - The template arguments of a variable template being accessed as a
   member will now be represented in the AST.
+- Fix C++17 mode assert when parsing malformed code and the compiler is
+  attempting to see if it could be type template for class template argument
+  deduction. This fixes
+  `Issue 57495 <https://github.com/llvm/llvm-project/issues/57495>`_
 
 
 Improvements to Clang's diagnostics


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