[Templight] Template Instantiation Observer

This patch adds a base-class called TemplateInstantiationObserver which gets
notified whenever a template instantiation is entered or exited during
semantic analysis. This is a base class used to implement the template
profiling and debugging tool called
Templight (https://github.com/mikael-s-persson/templight).

The patch also makes a few more changes:

* ActiveTemplateInstantiation class is moved out of the Sema class (so it can be used with inclusion of Sema.h).
* CreateFrontendAction function in front-end utilities is given external linkage (not longer a hidden static function).
* TemplateInstObserverChain data member added to Sema class to hold the list of template-inst observers.
* Notifications to the template-inst observer are added at the key places where templates are instantiated.

Patch by: Abel Sinkovics!

Differential Revision: https://reviews.llvm.org/D5767

llvm-svn: 324808

1 files changed, 3 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index b107f65adf1..95fd1665b40 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1358,6 +1358,8 @@ static InputKind ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
       Opts.ProgramAction = frontend::PrintPreamble; break;
     case OPT_E:
       Opts.ProgramAction = frontend::PrintPreprocessedInput; break;
+    case OPT_templight_dump:
+      Opts.ProgramAction = frontend::TemplightDump; break;
     case OPT_rewrite_macros:
       Opts.ProgramAction = frontend::RewriteMacros; break;
     case OPT_rewrite_objc:
@@ -2620,6 +2622,7 @@ static bool isStrictlyPreprocessorAction(frontend::ActionKind Action) {
   case frontend::RewriteObjC:
   case frontend::RewriteTest:
   case frontend::RunAnalysis:
+  case frontend::TemplightDump:
   case frontend::MigrateSource:
     return false;