[llvm] Avoid out-of-order evaluation in DebugInfo (#125116)

This is an upstream proposal from
https://github.com/intel/intel-graphics-compiler/commit/e60884cb98c4332a0eecff8396eb353c5b86cd35
We observed malfunctioning StripNonLineTableDebugInfo during debugging
and it's caused by out-of-order evaluation, this is a C++ level semantic
ambiguity issue, refer
https://en.cppreference.com/w/cpp/language/eval_order
Solution is simply separating one line into two.

1 files changed, 5 insertions, 1 deletions

diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index 4ce5180..ea1d79d 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -798,7 +798,11 @@ private:
 
       return getReplacementMDNode(N);
     };
-    Replacements[N] = doRemap(N);
+    // Seperate recursive doRemap and operator [] into 2 lines to avoid
+    // out-of-order evaluations since both of them can access the same memory
+    // location in map Replacements.
+    auto Value = doRemap(N);
+    Replacements[N] = Value;
   }
 
   /// Do the remapping traversal.