[PATCH] D82740: [libclang]: check validity before visiting Stmt node

[Milian Wolff via Phabricator via cfe-commits]

milianw created this revision.
milianw added reviewers: bkramer, yvvan, nik.
Herald added subscribers: cfe-commits, arphaman.
Herald added a project: clang.

Fixes crash when visiting a partial AST after encountering
a parse error in the input code:

  #5  clang::Stmt::getStmtClass (this=<optimized out>) at llvm-project/clang/include/clang/AST/Stmt.h:1125
  #6  clang::cxcursor::MakeCXCursor (S=S at entry=0x0, Parent=0x0, TU=0x7f8c6c5186b0, RegionOfInterest=...) at llvm-project/clang/tools/libclang/CXCursor.cpp:132
  #7  0x00007f8caddc96e5 in clang::cxcursor::CursorVisitor::EnqueueWorkList (this=this at entry=0x7f8c9bffc330, WL=..., S=S at entry=0x0) at llvm-project/clang/tools/libclang/CIndex.cpp:3028
  #8  0x00007f8cadde4e2c in clang::cxcursor::CursorVisitor::Visit (this=this at entry=0x7f8c9bffc330, S=0x0) at llvm-project/clang/tools/libclang/CIndex.cpp:3256
  #9  0x00007f8cadde4604 in clang::cxcursor::CursorVisitor::RunVisitorWorkList (this=this at entry=0x7f8c9bffc330, WL=...) at llvm-project/clang/tools/libclang/CIndex.cpp:3214
  #10 0x00007f8cadde4e37 in clang::cxcursor::CursorVisitor::Visit (this=this at entry=0x7f8c9bffc330, S=0x7f8c6c17dc30) at llvm-project/clang/tools/libclang/CIndex.cpp:3257
  #11 0x00007f8cadddeccb in clang::cxcursor::CursorVisitor::VisitChildren (this=this at entry=0x7f8c9bffc330, Cursor=...) at llvm-project/clang/tools/libclang/CIndex.cpp:515
  #12 0x00007f8cadde688f in clang_visitChildren (parent=..., visitor=0x7f8caef6ddda <(anonymous namespace)::visitCursor(CXCursor, CXCursor, CXClientData)>, client_data=0x7f8c9bffe3b0) at llvm-project/clang/tools/libclang/CIndex.cpp:4450


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D82740

Files:
  clang/tools/libclang/CIndex.cpp


Index: clang/tools/libclang/CIndex.cpp
===================================================================
--- clang/tools/libclang/CIndex.cpp
+++ clang/tools/libclang/CIndex.cpp
@@ -3243,6 +3243,8 @@
 }
 
 bool CursorVisitor::Visit(const Stmt *S) {
+  if (!S)
+    return false;
   VisitorWorkList *WL = nullptr;
   if (!WorkListFreeList.empty()) {
     WL = WorkListFreeList.back();


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