[PATCH] D122391: [llvm] Fix string copy confusion

[Nathan Sidwell via Phabricator via llvm-commits]

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The microsoft demangler makes copies of the demangled strings, but has some confusion between StringView representation (sans NUL), and C-strings (with NUL).  Here we also have a use of strcpy, which happens to work because the incoming string view happens to have a trailing NUL.  But a simple memcpy excluding the NUL is sufficient.

This is broken out of D120990 <https://reviews.llvm.org/D120990> and is a prerequisite of that patch.


https://reviews.llvm.org/D122391

Files:
  llvm/lib/Demangle/MicrosoftDemangle.cpp


Index: llvm/lib/Demangle/MicrosoftDemangle.cpp
===================================================================
--- llvm/lib/Demangle/MicrosoftDemangle.cpp
+++ llvm/lib/Demangle/MicrosoftDemangle.cpp
@@ -245,8 +245,8 @@
 }
 
 StringView Demangler::copyString(StringView Borrowed) {
-  char *Stable = Arena.allocUnalignedBuffer(Borrowed.size() + 1);
-  std::strcpy(Stable, Borrowed.begin());
+  char *Stable = Arena.allocUnalignedBuffer(Borrowed.size());
+  std::memcpy(Stable, Borrowed.begin(), Borrowed.size());
 
   return {Stable, Borrowed.size()};
 }


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