[PATCH] D84222: [AST][RecoveryExpr] Error-dependent expression should not be treat as a nullptr pointer constant.

[Haojian Wu via Phabricator via cfe-commits]

hokein created this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

If an expression is contains-error and its type is unknown (dependent), we
don't treat it as a null pointer constant.

Fix a recovery-ast crash on C.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D84222

Files:
  clang/lib/AST/Expr.cpp
  clang/test/AST/ast-dump-recovery.c


Index: clang/test/AST/ast-dump-recovery.c
===================================================================
--- clang/test/AST/ast-dump-recovery.c
+++ clang/test/AST/ast-dump-recovery.c
@@ -39,3 +39,14 @@
   // CHECK-NEXT:  `-DeclRefExpr {{.*}} 'a' 'const int'
   static int foo = a++; // verify no crash on local static var decl.
 }
+
+void test2() {
+  int* ptr;
+  // FIXME: the top-level expr should be a binary operator.
+  // CHECK:      ImplicitCastExpr {{.*}} contains-errors <LValueToRValue>
+  // CHECK-NEXT: `-RecoveryExpr {{.*}} contains-errors lvalue
+  // CHECK-NEXT:   |-DeclRefExpr {{.*}} 'ptr' 'int *'
+  // CHECK-NEXT:   `-RecoveryExpr {{.*}}
+  // CHECK-NEXT:     `-DeclRefExpr {{.*}} 'some_func'
+  ptr = some_func(); // should not crash
+}
Index: clang/lib/AST/Expr.cpp
===================================================================
--- clang/lib/AST/Expr.cpp
+++ clang/lib/AST/Expr.cpp
@@ -3744,7 +3744,8 @@
     case NPC_NeverValueDependent:
       llvm_unreachable("Unexpected value dependent expression!");
     case NPC_ValueDependentIsNull:
-      if (isTypeDependent() || getType()->isIntegralType(Ctx))
+      if ((!containsErrors() && isTypeDependent()) ||
+          getType()->isIntegralType(Ctx))
         return NPCK_ZeroExpression;
       else
         return NPCK_NotNull;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D84222.279429.patch
Type: text/x-patch
Size: 1316 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200721/679a9870/attachment.bin>