Represent C++ direct initializers as ParenListExprs before semantic analysis

instead of having a special-purpose function.

- ActOnCXXDirectInitializer, which was mostly duplication of
  AddInitializerToDecl (leading e.g. to PR10620, which Eli fixed a few days
  ago), is dropped completely.
- MultiInitializer, which was an ugly hack I added, is dropped again.
- We now have the infrastructure in place to distinguish between
  int x = {1};
  int x({1});
  int x{1};
-- VarDecl now has getInitStyle(), which indicates which of the above was used.
-- CXXConstructExpr now has a flag to indicate that it represents list-
   initialization, although this is not yet used.
- InstantiateInitializer was renamed to SubstInitializer and simplified.
- ActOnParenOrParenListExpr has been replaced by ActOnParenListExpr, which
  always produces a ParenListExpr. Placed that so far failed to convert that
  back to a ParenExpr containing comma operators have been fixed. I'm pretty
  sure I could have made a crashing test case before this.

The end result is a (I hope) considerably cleaner design of initializers.
More importantly, the fact that I can now distinguish between the various
initialization kinds means that I can get the tricky generalized initializer
test cases Johannes Schaub supplied to work. (This is not yet done.)

This commit passed self-host, with the resulting compiler passing the tests. I
hope it doesn't break more complicated code. It's a pretty big change, but one
that I feel is necessary.

llvm-svn: 150318

1 files changed, 13 insertions, 9 deletions

diff --git a/clang/lib/AST/DeclPrinter.cpp b/clang/lib/AST/DeclPrinter.cpp
index 5a6686d1648..32bdba1a0b2 100644
--- a/clang/lib/AST/DeclPrinter.cpp
+++ b/clang/lib/AST/DeclPrinter.cpp
@@ -621,16 +621,20 @@ void DeclPrinter::VisitVarDecl(VarDecl *D) {
   Out << Name;
   Expr *Init = D->getInit();
   if (!Policy.SuppressInitializers && Init) {
-    if (D->hasCXXDirectInitializer())
-      Out << "(";
-    else {
-        CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init);
-        if (!CCE || CCE->getConstructor()->isCopyOrMoveConstructor())
-          Out << " = ";
+    bool ImplicitInit = false;
+    if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init))
+      ImplicitInit = D->getInitStyle() == VarDecl::CallInit &&
+          Construct->getNumArgs() == 0 && !Construct->isListInitialization();
+    if (!ImplicitInit) {
+      if (D->getInitStyle() == VarDecl::CallInit)
+        Out << "(";
+      else if (D->getInitStyle() == VarDecl::CInit) {
+        Out << " = ";
+      }
+      Init->printPretty(Out, Context, 0, Policy, Indentation);
+      if (D->getInitStyle() == VarDecl::CallInit)
+        Out << ")";
     }
-    Init->printPretty(Out, Context, 0, Policy, Indentation);
-    if (D->hasCXXDirectInitializer())
-      Out << ")";
   }
   prettyPrintAttributes(D);
 }