[TableGen] Make Record::getValueAsString and getValueAsListOfStrings return StringRefs instead of std::string

Internally both these methods just return the result of getValue on either a StringInit or a CodeInit object. In both cases this returns a StringRef pointing to a string allocated in the BumpPtrAllocator so its not going anywhere. So we can just pass that StringRef along.

This is a fairly naive patch that targets just the build failures caused by this change. There's additional work that can be done to avoid creating std::string at call sites that still think getValueAsString returns a std::string. I'll try to clean those up in future patches.

Differential Revision: https://reviews.llvm.org/D33710

llvm-svn: 304325

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/utils/TableGen/AsmWriterEmitter.cpp b/llvm/utils/TableGen/AsmWriterEmitter.cpp
index 40b7857ab99..4b06e9e247f 100644
--- a/llvm/utils/TableGen/AsmWriterEmitter.cpp
+++ b/llvm/utils/TableGen/AsmWriterEmitter.cpp
@@ -523,7 +523,7 @@ emitRegisterNameString(raw_ostream &O, StringRef AltName,
       // If the register has an alternate name for this index, use it.
       // Otherwise, leave it empty as an error flag.
       if (Idx < e) {
-        std::vector<std::string> AltNames =
+        std::vector<StringRef> AltNames =
           Reg.TheDef->getValueAsListOfStrings("AltNames");
         if (AltNames.size() <= Idx)
           PrintFatalError(Reg.TheDef->getLoc(),