[PATCH] D102069: [clang][PreProcessor] Cutoff parsing after hitting completion point

[Kadir Cetinkaya via Phabricator via cfe-commits]

kadircet created this revision.
kadircet added a reviewer: hokein.
kadircet requested review of this revision.
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This fixes a crash caused by Lexers being invalidated at code
completion points in
https://github.com/llvm/llvm-project/blob/main/clang/lib/Lex/PPLexerChange.cpp#L520.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D102069

Files:
  clang/lib/Lex/PPDirectives.cpp
  clang/test/CodeCompletion/crash-if-directive.cpp


Index: clang/test/CodeCompletion/crash-if-directive.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeCompletion/crash-if-directive.cpp
@@ -0,0 +1,3 @@
+#define FOO(X) X + 1
+#if FOO(
+// RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:2:9 %s | FileCheck %s --allow-empty
Index: clang/lib/Lex/PPDirectives.cpp
===================================================================
--- clang/lib/Lex/PPDirectives.cpp
+++ clang/lib/Lex/PPDirectives.cpp
@@ -3023,6 +3023,10 @@
   IdentifierInfo *IfNDefMacro = nullptr;
   const DirectiveEvalResult DER = EvaluateDirectiveExpression(IfNDefMacro);
   const bool ConditionalTrue = DER.Conditional;
+  // Lexer might become invalid if we hit code completion point while evulating
+  // expression.
+  if (!CurPPLexer)
+    return;
 
   // If this condition is equivalent to #ifndef X, and if this is the first
   // directive seen, handle it for the multiple-include optimization.


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