[pseudo] Fix an out-of-bound issue in getReduceRules.

2022-07-01 20:16:06 +02:00 · 2022-07-01 20:16:06 +02:00 · c998273499
parent 6e8ec13d3f
commit c998273499
1 changed files with 4 additions and 1 deletions
--- a/clang-tools-extra/pseudo/include/clang-pseudo/grammar/LRTable.h
+++ b/clang-tools-extra/pseudo/include/clang-pseudo/grammar/LRTable.h
@ -140,8 +140,11 @@ public:
  //     // ...apply reduce...
  //   }
  llvm::ArrayRef<RuleID> getReduceRules(StateID State) const {
+    if (ReduceOffset[State] >= Reduces.size())
+      return {};
+    size_t Length = ReduceOffset[State + 1] - ReduceOffset[State];
    return llvm::makeArrayRef(&Reduces[ReduceOffset[State]],
-                              &Reduces[ReduceOffset[State + 1]]);
+                              Length);
  }
  // Returns whether Terminal can follow Nonterminal in a valid source file.
  bool canFollow(SymbolID Nonterminal, SymbolID Terminal) const {