[clang][ifs] Clang Interface Stubs ToolChain plumbing.

Second Landing Attempt:

This patch enables end to end support for generating ELF interface stubs
directly from clang. Now the following:

clang -emit-interface-stubs -o libfoo.so a.cpp b.cpp c.cpp

will product an ELF binary with visible symbols populated. Visibility attributes
and -fvisibility can be used to control what gets populated.

* Adding ToolChain support for clang Driver IFS Merge Phase
* Implementing a default InterfaceStubs Merge clang Tool, used by ToolChain
* Adds support for the clang Driver to involve llvm-ifs on ifs files.
* Adds -emit-merged-ifs flag, to tell llvm-ifs to emit a merged ifs text file
  instead of the final object format (normally ELF)


Differential Revision: https://reviews.llvm.org/D63978

llvm-svn: 374061

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/lib/Driver/Phases.cpp b/clang/lib/Driver/Phases.cpp
index 5b776c63f71..01598c59bd9 100644
--- a/clang/lib/Driver/Phases.cpp
+++ b/clang/lib/Driver/Phases.cpp
@@ -20,6 +20,7 @@ const char *phases::getPhaseName(ID Id) {
   case Backend: return "backend";
   case Assemble: return "assembler";
   case Link: return "linker";
+  case IfsMerge: return "ifsmerger";
   }
 
   llvm_unreachable("Invalid phase id.");