[PATCH] D116826: Initialize output parameters

[Vitaly Buka via Phabricator via llvm-commits]

vitalybuka created this revision.
vitalybuka added reviewers: kda, eugenis.
Herald added subscribers: dexonsmith, hiraditya.
vitalybuka requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

If the function returns true, it should
set all output paremeters, similar to Output::preflightElement, or we
have UB on code like:

  void *SaveInfo;
  if (io.preflightFlowElement(i, SaveInfo))
    io.postflightFlowElement(SaveInfo);

It's going to be detected by msan with:
-Xclang -enable-noundef-analysis -mllvm -msan-eager-checks=1


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D116826

Files:
  llvm/lib/Support/YAMLTraits.cpp


Index: llvm/lib/Support/YAMLTraits.cpp
===================================================================
--- llvm/lib/Support/YAMLTraits.cpp
+++ llvm/lib/Support/YAMLTraits.cpp
@@ -629,7 +629,7 @@
   outputUpToEndOfLine(" ]");
 }
 
-bool Output::preflightFlowElement(unsigned, void *&) {
+bool Output::preflightFlowElement(unsigned, void *&SaveInfo) {
   if (NeedFlowSequenceComma)
     output(", ");
   if (WrapColumn && Column > WrapColumn) {
@@ -639,6 +639,7 @@
     Column = ColumnAtFlowStart;
     output("  ");
   }
+  SaveInfo = nullptr;
   return true;
 }
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D116826.398197.patch
Type: text/x-patch
Size: 568 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220107/fcefdeb7/attachment.bin>