[AVX] Make Inits Foldable

Manage Inits in a FoldingSet.  This provides several benefits:

- Memory for Inits is properly managed

- Duplicate Inits are folded into Flyweights, saving memory

- It enforces const-correctness, protecting against certain classes
  of bugs

The above benefits allow Inits to be used in more contexts, which in
turn provides more dynamism to TableGen.  This enhanced capability
will be used by the AVX code generator to a fold common patterns
together.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134907 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 4 deletions

diff --git a/utils/TableGen/ClangAttrEmitter.cpp b/utils/TableGen/ClangAttrEmitter.cpp
index 26bd8786a4..bca4bb61c2 100644
--- a/utils/TableGen/ClangAttrEmitter.cpp
+++ b/utils/TableGen/ClangAttrEmitter.cpp
@@ -21,17 +21,19 @@ using namespace llvm;
 
 static const std::vector<StringRef>
 getValueAsListOfStrings(Record &R, StringRef FieldName) {
-  ListInit *List = R.getValueAsListInit(FieldName);
+  const ListInit *List = R.getValueAsListInit(FieldName);
   assert (List && "Got a null ListInit");
 
   std::vector<StringRef> Strings;
   Strings.reserve(List->getSize());
 
-  for (ListInit::iterator i = List->begin(), e = List->end(); i != e; ++i) {
+  for (ListInit::const_iterator i = List->begin(), e = List->end();
+       i != e;
+       ++i) {
     assert(*i && "Got a null element in a ListInit");
-    if (StringInit *S = dynamic_cast<StringInit *>(*i))
+    if (const StringInit *S = dynamic_cast<const StringInit *>(*i))
       Strings.push_back(S->getValue());
-    else if (CodeInit *C = dynamic_cast<CodeInit *>(*i))
+    else if (const CodeInit *C = dynamic_cast<const CodeInit *>(*i))
       Strings.push_back(C->getValue());
     else
       assert(false && "Got a non-string, non-code element in a ListInit");