Lazily declare default constructors. We now delay the construction of

declarations for implicit default constructors, copy constructors,
copy assignment operators, and destructors. On a "simple" translation
unit that includes a bunch of C++ standard library headers, we
generate relatively few of these implicit declarations now:

  4/159 implicit default constructors created
  18/236 implicit copy constructors created
  70/241 implicit copy assignment operators created
  0/173 implicit destructors created

And, on this translation unit, this optimization doesn't really
provide any benefit. I'll do some more performance measurements soon,
but this completes the implementation work for <rdar://problem/8151045>.

llvm-svn: 107551

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 4737abc3e35..2d52bd08d55 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -31,6 +31,8 @@
 
 using namespace clang;
 
+unsigned ASTContext::NumImplicitDefaultConstructors;
+unsigned ASTContext::NumImplicitDefaultConstructorsDeclared;
 unsigned ASTContext::NumImplicitCopyConstructors;
 unsigned ASTContext::NumImplicitCopyConstructorsDeclared;
 unsigned ASTContext::NumImplicitCopyAssignmentOperators;
@@ -261,6 +263,9 @@ void ASTContext::PrintStats() const {
   fprintf(stderr, "Total bytes = %d\n", int(TotalBytes));
 
   // Implicit special member functions.
+  fprintf(stderr, "  %u/%u implicit default constructors created\n",
+          NumImplicitDefaultConstructorsDeclared, 
+          NumImplicitDefaultConstructors);
   fprintf(stderr, "  %u/%u implicit copy constructors created\n",
           NumImplicitCopyConstructorsDeclared, 
           NumImplicitCopyConstructors);