[PATCH] D84140: [clang] Set the error-bit for ill-formed semantic InitListExpr.

[Haojian Wu via Phabricator via cfe-commits]

hokein created this revision.
hokein added a reviewer: sammccall.
Herald added subscribers: kbobyrev, usaxena95, kadircet, arphaman, jkorous.
Herald added a project: clang.

When a semantic checking fails on a syntactic InitListExpr, we will
get an ill-formed semantic InitListExpr (e.g. some inits are nullptr),
using this semantic InitListExpr in clang (without setting the err-bits) is crashy.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D84140

Files:
  clang-tools-extra/clangd/unittests/HoverTests.cpp
  clang/include/clang/AST/Expr.h
  clang/lib/Sema/SemaInit.cpp


Index: clang/lib/Sema/SemaInit.cpp
===================================================================
--- clang/lib/Sema/SemaInit.cpp
+++ clang/lib/Sema/SemaInit.cpp
@@ -962,6 +962,8 @@
       FillInEmptyInitializations(Entity, FullyStructuredList,
                                  RequiresSecondPass, nullptr, 0);
   }
+  if (hadError && FullyStructuredList)
+    FullyStructuredList->markError();
 }
 
 int InitListChecker::numArrayElements(QualType DeclType) {
Index: clang/include/clang/AST/Expr.h
===================================================================
--- clang/include/clang/AST/Expr.h
+++ clang/include/clang/AST/Expr.h
@@ -4690,6 +4690,14 @@
       setDependence(getDependence() | expr->getDependence());
   }
 
+  /// Mark the semantic form of the InitListExpr as error when the semantic
+  /// analysis fails.
+  void markError() {
+    assert(isSemanticForm());
+    setDependence(getDependence() | ExprDependence::Error |
+                  ExprDependence::ValueInstantiation);
+  }
+
   /// Reserve space for some number of initializers.
   void reserveInits(const ASTContext &C, unsigned NumInits);
 
Index: clang-tools-extra/clangd/unittests/HoverTests.cpp
===================================================================
--- clang-tools-extra/clangd/unittests/HoverTests.cpp
+++ clang-tools-extra/clangd/unittests/HoverTests.cpp
@@ -957,6 +957,16 @@
           template <typename T> void foo() {
             (void)[[size^of]](T);
           })cpp",
+      R"cpp(// should not crash on invalid semantic form of init-list-expr.
+            /*error-ok*/
+            struct Foo {
+              int xyz = 0;
+            };
+            class Bar {};
+            constexpr Foo s = ^{
+              .xyz = Bar(),
+            };
+          )cpp",
       // literals
       "auto x = t^rue;",
       "auto x = '^A';",


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